CARBAMYLOXY COMPOUNDS WHICH INHIBIT LEUKOCYTE ADHESION MEDIATED BY VLA-4

Abstract: Disclosed are compounds which bind VLA-4. Certain of these compounds also inhibit leukocyte adhesion and, in particular, leukocyte adhesion mediated by VLA-4. Such compounds are useful in the treatment of inflammatory diseases in a mammalian patient, e.g., human, such as asthma, Alzheimer's disease, atherosclerosis, AIDS dementia, diabetes, inflammatory bowel disease, rheumatoid arthritis, tissue transplantation, tumor metastasis and myocardial ischemia. The compounds can also be administered for the treatment of inflammatory brain diseases such as multiple sclerosis.

Description: CARBAMYLOXY COMPOUNDS WHICH INHIBIT LEUKOCYTE ADHESION MEDIATED BY VLA-4 BACKGROUND OF THE INVENTION Field of the Invention This invention relates to compounds which inhibit leukocyte adhesion and, in particular, leukocyte adhesion mediated by VLA-4. References The following publications, patents and patent applications are cited in this application as superscript numbers: ι Hemler and Takada, European Patent Application Publication No. 330,506, published August 30, 1989 2 Elices, et al. , Cell, 60:577-584 (1990) 3 Springer, Nature, 346:425-434 (1990) Osborn, Cell, 62:3-6 (1990) 5 Vedder, et al., Surgery, 106:509 (1989) 6 Pretolani, et al. , J. Exp. Med. , 180:795 (1994) 7 Abraham, et al. , J. Clin. Invest. , 93:776 (1994) 8 Mulligan, et al., J. Immunology, 150:2407 (1993) 9 Cybulsky, et al. , Science, 251:788 (1991) 10 Li, et al. , Arterioscler. Thromb. , 13: 197 (1993) 11 Sasseville, et al. , Am. J. Path. , 144:27 (1994) 12 Yang, et al., Proc. Nat. Acad. Science (USA), 90: 10494 (1993) 13 Burkly , et al. , Diabetes, 43 :529 (1994) 14 Baron, et al., J. Clin. Invest. , 93: 1700 (1994) 15 Hamann, et al., J. Immunology, 152:3238 (1994) 16 Yednock, et al., Nature, 356:63 (1992) " Baron, et al . , J. Exp. Med. , 177 : 57 ( 1993) 18 van Dinther-Janssen, et al., J. Immunology, 147:4207 (1991) 19 van Dinther-Janssen, et al., Annals. Rheumatic Dis. , 52:612 (1993) 20 Elices, et al., J. Clin. Invest. , 93:405 (1994) 21 Postigo, et al. , J. Clin. Invest. , 89: 1445 (1991) 22 Paul, et al., Transpl. Proceed. , 25:813 (1993) 23 Okarhara, et al., Can. Res. , 54:3233 (1994) 24 Paavonen, et al., Int. J. Can. , 58:298 (1994) 2 5 Schadendorf, et al., J. Path. , 170:429 (1993) 2 6 Bao, et al., Diff. , 52:239 (1993) 2 7 Lauri, et al., British J. Cancer, 68:862 (1993) 2 8 Kawaguchi, et al. , Japanese J. Cancer Res. , .83:1304 (1992) 29 Kogan, et al. , U.S. Patent No. 5,510,332, issued April 23, 1996 3 o International Patent Appl. Publication No. WO 96/01644 All of the above publications, patents and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety. State of the Art VLA-4 (also referred to as α4βl integrin and CD49d/CD29), first identified by Hemler and Takada 1 is a member of the βl integrin family of cell surface receptors, each of which comprises two subunits, an α chain and a β chain. VLA-4 contains an 4 chain and a βl chain. There are at least nine βl integrins, all sharing the same βl chain and each having a distinct α chain. These nine receptors all bind a different complement of the various cell matrix molecules, such as fibronectin, laminin, and collagen. VLA-4, for example, binds to fibronectin. VLA-4 is unique among integrins in that it also binds non-matrix molecules that are expressed by endothelial and other cells. These non-matrix molecules include VCAM-1, which is expressed on cytokine-activated human umbilical vein endothelial cells in culture. Distinct epitopes of VLA-4 are responsible for the fibronectin and VCAM-1 binding activities and each activity has been shown to be inhibited independently. 2 Intercellular adhesion mediated by VLA-4 and other cell surface receptors is associated with a number of inflammatory responses. At the site of an injury or other inflammatory stimulus, activated vascular endothelial cells express molecules that are adhesive for leukocytes. The mechanics of leukocyte adhesion to endothelial cells involves, in part, the recognition and binding of cell surface receptors on leukocytes to the corresponding cell surface molecules on endothelial cells. Once bound, the leukocytes migrate across the blood vessel wall to enter the injured site and release chemical mediators to combat infection. For reviews of adhesion receptors of the immune system, see, for example, Springer 3 and Osborn 4 . Inflammatory brain disorders, such as experimental autoimmune encephalomyelitis (EAE), multiple sclerosis (MS) and meningitis, are examples of central nervous system disorders in which the endothelium/leukocyte adhesion mechanism results in destruction to otherwise healthy brain tissue. Large numbers of leukocytes migrate across the blood brain barrier (BBB) in subjects with these inflammatory diseases. The leukocytes release toxic mediators that cause extensive tissue damage resulting in impaired nerve conduction and paralysis. In other organ systems, tissue damage also occurs via an adhesion mechanism resulting in migration or activation of leukocytes. For example, it has been shown that the initial insult following myocardial ischemia to heart tissue can be further complicated by leukocyte entry to the injured tissue causing still further insult (Vedder et al. 5 ). Other inflammatory conditions mediated by an adhesion mechanism include, by way of example, asthma 6"8 , Alzheimer's disease, atherosclerosis 9 10 , AIDS dementia 11 , diabetes 12 14 (including acute juvenile onset diabetis), inflammatory bowel disease 15 (including ulcerative colitis and Crohn' s disease), multiple sclerosis 16"17 , rheumatoid arthritis 1821 , tissue transplantation 22 , tumor metastasis 23 28 , meningitis, encephalitis, stroke, and other cerebral traumas, nephritis, retinitis, atopic dermatitis, psoriasis, myocardial ischemia and acute leukocyte-mediated lung injury such as that which occurs in adult respiratory distress syndrome. In view of the above, assays for determining the VLA-4 level in a biological sample containing VLA-4 would be useful, for example, to diagnosis VLA-4 mediated conditions. Additionally, despite these advances in the understanding of leukocyte adhesion, the art has only recently addressed the use of inhibitors of adhesion in the treatment of inflammatory brain diseases and other inflammatory conditions 2930 . The present invention addresses these and other needs. SUMMARY OF THE INVENTION This invention provides compounds which bind to VLA-4. Such compounds can be used, for example, to assay for the presence of VLA-4 in a sample and, in pharmaceutical compositions to inhibit cellular adhesion mediated by VLA-4, for example, binding of VCAM-1 to VLA-4. The compounds of this invention have a binding affinity to VLA-4 as expressed by an IC 50 of about 15 μM or less (measured as described in Example A below) which compounds are defined by formula I below: wherein R 1 is selected from the group consisting of alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocylic, heteroaryl and substituted heteroaryl; R 2 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heterocyclic, substituted heterocyclic, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, and R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 can form a heterocyclic or a substituted heterocyclic group; R 3 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic and, when R 2 does not form a heterocyclic group with R 1 , R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 can form a heterocyclic or a substituted heterocyclic group; R 5 is -(CH 2 ) X -Ar-R 5 where R 5 is selected from the group consisting of -O-Z-NR 8 R 8' and -O-Z-R 12 wherein R 8 and R 8' are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, and where R 8 and R 8 are joined to form a heterocycle or a substituted heterocycle, R 12 is selected from the group consisting of heterocycle and substituted heterocycle, and Z is selected from the group consisting of -C(O)- and -SQ-, Ar is aryl, heteroaryl, substituted aryl or substituted heteroaryl, x is an integer of from 1 to 4; Q is -C(X)NR 7 - wherein R 7 is selected from the group consisting of hydrogen and alkyl; and X is selected from the group consisting of oxygen and sulfur; and pharmaceutically acceptable salts thereof. In another embodiment, the compounds of this invention can also be provided as prodrugs which convert (e.g. , hydrolyze, metabolize, etc.) in vivo to a compound of formula I above. In a preferred example of such an embodiment, the carboxylic acid group of the compound of formula I is modified into a group which, in vivo, will convert to a carboxylic acid group (including salts thereof). In a particularly preferred embodiment, such prodrugs are represented by compounds of formula IA: IA wherein R 1 is selected from the group consisting of alkyl, substituted alkyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocylic, heteroaryl and substimted heteroaryl; R 2 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, substimted cycloalkyl, cycloalkenyl, substimted cycloalkenyl, heterocyclic, substimted heterocyclic, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, and R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 can form a heterocyclic or a substituted heterocyclic group; R 3 is selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and, when R 2 does not form a heterocyclic group with R 1 , R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 can form a heterocyclic or a substituted heterocyclic group; R 5 is -(CH 2 ) X -Ar-R 5 where R 5 is selected from the group consisting of -O-Z-NR 8 R 8 and -O-Z-R 12 wherein R 8 and R 8' are independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocyclic, and where R 8 and R 8 are joined to form a heterocycle or a substimted heterocycle, R 12 is selected from the group consisting of heterocycle and substimted heterocycle, and Z is selected from the group consisting of -C(O)- and -SO 2 -, Ar is aryl, heteroaryl, substituted aryl or substimted heteroaryl, x is an integer of from 1 to 4; R 6 is selected from the group consisting of 2,4-dioxo-tetrahydrofuran- 3-yl (3,4-enol), amino, alkoxy, substimted alkoxy, cycloalkoxy, substimted cycloalkoxy, -O-(N-succinimidyl), -NH-adamantyl, -O-cholest-5-en-3-β-yl, - NHOY where Y is hydrogen, alkyl, substimted alkyl, aryl, and substituted aryl, -NH(CH 2 ) p COOY where ? is an integer of from 1 to 8 and Y is as defined above, -OCH 2 NR 9 R 10 where R 9 is selected from the group consisting of -C(O)-aryl and -C(O)-substituted aryl and R 10 is selected from the group consisting of hydrogen and -CH 2 COOR u where R 11 is alkyl, and -NHSO 2 Z' where Z' is alkyl, substituted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic; Q is -C(X)NR 7 - wherein R 7 is selected from the group consisting of hydrogen and alkyl; and X is selected from the group consisting of oxygen and sulfur; and pharmaceutically acceptable salts thereof with the following provisos (A) when R 1 and R 2 together with the SO 2 group pendent to R 1 and the nitrogen pendent to R 2 form a saccharin-2-yl group, R 3 is -CH 3 , R 5 is -[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; (B) when R 1 is p-methylphenyl, R 2 and R 3 together with the nitrogen atom pendent to R 2 and the carbon atom pendent to R 3 form a pyrrodinyl ring derived from D-proline; R 5 is /?-[(4-methylpiperazin-l-yl)NC(O)O- jbenzyl derived from D-phenylalanine and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; (C) when R 1 is pyrimidin-2-yl, R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 form a pyrrolidinyl ring, R 5 is /?-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 . (D) when R 1 is /?-methylphenyl, R 2 and R 3 together with the nitrogen atom pendent to R 2 and the carbon atom pendent to R 3 form a (2S)-piperazin- 2-carbonyl ring; R 5 is /?-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 . Preferably, in the compounds of formula I and IA above, R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heterocyclic, substimted heterocylic, heteroaryl and substimted heteroaryl. Even more preferably R 1 is selected from the group consisting of methyl, isopropyl, n-butyl, benzyl, phenethyl, phenyl, 4- methylphenyl, 4-t-butylphenyl, 2,4,6-trimethylphenyl, 2-fluorophenyl, 3- fluorophenyl, 4-fluorophenyl, 2,4-difluorophenyl, 3,4-difluorophenyl, 3,5- difluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3,4- dichlorophenyl, 3,5-dichlorophenyl, 3-chloro-4-fluorophenyl, 4- bromophenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 3,4- dimethoxyphenyl, 4-t-butoxyphenyl, 4-(3 xdimethylamino-n-propoxy)- phenyl, 2-carboxyphenyl, 2-(methoxycarbonyl)phenyl, 4-(H 2 NC(O)-)phenyl, 4-(H 2 NC(S)-)phenyl, 4-cyanophenyl, 4-trifluoromethylphenyl, 4- trifluoromethoxyphenyl, 3,5-di-(trifluoromethyl)phenyl, 4-nitrophenyl, 4- aminophenyl, 4-(CH 3 C(O)NH-)phenyl, 4-(PhNHC(O)NH-)phenyl, 4- amidinophenyl, 4-methylamidinophenyl, 4-(CH 3 SC(=NH)-)phenyl, 4- chloro-3-(H 2 NS(O) 2 -)phenyl, 1-naphthyl, 2-naphthyl, pyridin-2-yl, pyridin-3- yl, pyrimidin-2-yl, quinolin-8-yl, 2-(trifluoroacetyl)-l,2,3,4- tetrahydroisoquinolin-7-yl, mo holin-4-yl, 2-thienyl, 5-chloro-2-thienyl, 2,5-dichloro-4-thienyl, l-N-methylimidazol-4-yl, l-N-methylpyrazol-3-yl, 1- N-methylpyrazol-4-yl, l-N-butylpyrazol-4-yl, l-N-methyl-3-methyl-5- chloropyrazol-4-yl , 1 -N-methyl-5-methy l-3-chloropyrazol-4-yl , 2-thiazolyl and 5-methyl-l ,3,4-thiadiazol-2-yl. Preferably, in the compounds of formula I and I A above, R 2 is hydrogen, methyl, phenyl, benzyl, -(CH 2 ) 2 -2-thienyl, and -(CH 2 ) 2 -φ. In one embodiment, R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 are joined to form a heterocyclic group or substimted heterocyclic group. Preferred heterocyclic and substimted heterocyclic groups include those having from 5 to 7 ring atoms having 2 to 3 heteroatoms in the ring selected from the group consisting of nitrogen, oxygen and sulfur which ring is optionally fused to another ring such as a phenyl or cyclohexyl ring to provide for a fused ring heterocycle of from 10 to 14 ring atoms having 2 to 4 heteroatoms in the ring selected from the group consisting of nitrogen, oxygen and sulfur. Specifically preferred RVR 2 joined groups include, by way of example, benzisothiazolonyl (saccharin-2-yl), N-2,10-camphorsultamyl and l,l-dioxo-2,3-dihydro-3,3- dimethyl- 1 ,2-benzisothiazol-2-yl . In one preferred embodiment, R 2 and R 3 together with the nitrogen atom bound to R 2 substiment and the carbon bound to the R 3 substiment form a heterocyclic group or a substimted heterocyclic group of 4 to 6 ring atoms having 1 to 2 heteroatoms in the ring selected from the group consisting of nitrogen, oxygen and sulfur which ring is optionally substimted with 1 to 2 substiments selected from the group consisting of fluoro, methyl, hydroxy, oxo ( = O), amino, phenyl, thiophenyl, thiobenzyl, (thiomorpholin-4- yl)C(O)O- , CH 3 S(O) 2 - and CH 3 S(O) 2 O-, or can be fused to another ring such as a phenyl or cycloalkyl ring to provide for a fused ring heterocycle of from 10 to 14 ring atoms having 1 to 2 heteroatoms in the ring selected from the group consisting of nitrogen, oxygen and sulfur. Such heterocyclic rings include azetidinyl (e.g., L-azetidinyl), thiazolidinyl (e.g. , L-thiazolidinyl), piperidinyl (e.g., L-piperidinyl), piperazinyl (e.g., L-piperazinyl), dihydroindolyl (e.g., L-2,3-dihydroindol-2-yl), tetrahydroquinolinyl (e.g., L-l,2,3,4-tetrahydroquinolin-2-yl), thiomorpholinyl (e.g., L-thiomorpholin- 3-yl), pyrrolidinyl (e.g., L-pyrrolidinyl), substimted pyrrolidinyl such as 4-hydroxypyrrolidinyl (e.g., 4-α-(or β-)hydroxy-L-pyrrolidinyl), 4- oxopyrrolidinyl (e.g., 4-oxo-L-pyrolidinyl), 4-fluoropyrrolidinyl (e.g., 4-α- (or β-)fluoro-L-pyrrolidinyl), 4,4-difluoropyrrolidinyl (e.g., 4,4-difluoro-L- pyrrolidinyl), 4-(thiomorpholin-4-ylC(O)O-)pyrrolidinyl (e.g., 4- -(or β-)- (thiomorpholin-4-ylC(O)O-)-L-pyrrolidinyl, 4-(CH 3 S(O) 2 O-)pyrrolidinyl (e.g. , 4- -(or β-)(CH 3 S(O) 2 O-)-L-pyrrolidinyl, 3-phenylpyrrolidinyl (e.g., 3- α-(or β-)phenyl-L-pyrrolidinyl), 3-thiophenylpyrrolidinyl (e.g., 3-α-(or β-)- thiophenyl-L-pyrrolidinyl), 4-aminopyrrolidinyl (e.g., 4-α-(or β-)amino-L- pyrrolidinyl), 3-methoxypyrrolidinyl (e.g., 3-α-(or β-)methoxy-L- pyrrolidinyl), 4,4-dimethylpyrrolidinyl, substimted piperazinyl such as 4-N- Cbz-piperazinyl and 4-(CH 3 S(O) 2 -)piperazinyl, substituted thiazolidinyl such as 5,5-dimethylthiazolindin-4-yl, 1,1-dioxo-thiazolidinyl (e.g., L-l,l-dioxo- thiazolidin-2-yl), substimted 1,1-dioxo-thiazolidinyl such as L-l,l-dioxo-5,5- dimethylthiazolidin-2-yl , 1,1 -dioxothiomorpholinyl (e.g., L- 1 , 1 -dioxo- thiomorpholin-3-yl) and the like. Preferably, in the compounds of formula I and I A above, R 3 includes all of the isomers arising by substitution with methyl, phenyl, benzyl, diphenylmethyl, -CH 2 CH 2 -COOH, -CH 2 -COOH, 2-amidoethyl, iso-b ty\, t- butyl, -CH 2 O-benzyl and hydroxymethyl. Additionally, in another preferred embodiment, R 3 and R 2 together with the nitrogen atom bound to R 2 can form a heterocyclic group or substimted heterocyclic group. Q is preferably -C(O)NH- or -C(S)NH-. Ar is preferably aryl or substimted aryl and, even more preferably, is phenyl or substimted phenyl. Preferably, x is 1. R 5 is preferably selected from all possible isomers arising by substitution with the following groups: 3-[(CH 3 ) 2 NC(O)O-]benzyl, 4-[(CH 3 ) 2 NC(O)O-]benzyl, 4-[(CH 3 ) 2 NS(O) 2 O-]benzyl, 4-[(piperidin-l Xyl)C(O)O-]benzyl, 4-[(piperidin-4Xyl)C(O)O-]benzyl, 4-[(r-methylpiρeridin-4 X yl)C(O)O-]benzyl, 4- [(4 '-hydroxypiperidin- 1 ' -yl)C(O)O-]benzyl , 4- [(4 ' -formyloxypiperidin- 1 ' -yl)C(O)O-]benzyl , 4-[(4Xethoxycarbonylpiperidin-l Xyl)C(O)O-]benzyl, 4-[(4 X carboxylpiperidin- -yl)C(O)O-]benzyl, 4-[(3 Xhydroxymethylpiperidin-1 Xyl)C(O)O-]benzyl, - [(4 ' -hydroxymethylpiperidin- 1 ' -y 1)C (O)O-] benzyl , -[(4'-phenyl-l '-Boc-piperidin-4'-yl)-C(O)O-]benzyl, -[(4 X piperidon-r-yl ethylene ketal)C(O)O-]benzyl, -[(piperazin-4Xyl)-C(O)O-]benzyl, -[(l '-Boc-piperazin-4'-yl)-C(O)O-]benzyl, - [(4 X methy lpiperazin- r-yl)C(O)O-]benzyl, -[(4 X methylhomopiperazin- -yl)C(O)O-]benzyl, -[(4 X (2-hydroxyethyl)piperazin-r-yl)C(O)O-]benzyl, -[(4 X phenylpiperazin- -yl)C(O)O-]benzyl , -[(4 X (pyridin-2-yl)piperazin-r-yl)C(O)O-]benzyl, - [(4 X (4-trifluoromethy lpyridin-2-y l)piperazin- 1 ' -y l)C(O)O-]benzyl , - [(4 X (pyrimidin-2-yl)piperazin- -yl)C(O)O-]benzyl , -[(4 X acetylpiperazin- 1 '-yl)C(O)O-]benzyl , -[(4 X (phenylC(O)-)piperazin-r-yl)C(O)O-]benzyl, -[(4 X (pyridin-4-ylC(O)-)piρerazin-r-yl)C(O)O-]benzyl, -[(4'-(phenylNHC(O)-)ρiρerazin-l '-yl)C(O)O-]benzyl, -[(4 X (phenylNHC(S)-)piperazin-r-yl)C(O)O-]benzyl, - [(4 ' -methanesulfony lpiperazin- 1 ' -y l-C(O)O-)benzyl , - [(4 xtrifluoromethanesulfony lpiperazin- 1 ' -y l-C(O)O-)benzyl , -[(morpholin-4Xyl)C(O)O-]benzyl, -nitro-4-[(morpholin-4Xyl)-C(O)O-]benzyl, -[(thiomorpholin-4Xyl)C(O)O-]benzyl, -[(thiomorpholin-4Xyl sulfone)-C(O)O-]benzyl, (alternative nomenclature 4-[(l,l-dioxothiomorpholin-4-yl)- C(O)O-]benzyl), -[(pyrrolidin-r-yl)C(O)O-]benzyl, -[(2'-methylpyrrolidin-l'-yl)C(O)O-]benzyl, -[(2 X (methoxycarbonyl)pyrrolidin- -yl)C(O)O-]benzyl, -[(2 X (hydroxymethyl)pyrrolidin-r-yl)C(O)O-]benzyl, -[(2 X (N,N-dimethylamino)ethyl)(CH 3 )NC(O)O-]benzyl, -[(2 X (N-methyl-N-toluene-4-sulfonylamino)ethyl)(CH 3 )N- C(O)O-]benzyl, 4-[(2'-(morpholin-4'-yl)ethyl)(CH 3 )NC(O)O-]benzyl, 4-[(2'-(hydroxy)ethyl)(CH 3 )NC(O)O-]benzyl, 4-[bis(2'-(hydroxy)ethyl)NC(O)O-]benzyl, 4-[(2X(formyloxy)ethyl)(CH 3 )NC(O)O-]benzyl, 4-[(CH 3 OC(O)CH 2 )HNC(O)O-]benzyl, 4-[2X(phenylNHC(O)O-)ethyl-]HNC(O)O-]benzyl, 3-chloro-4-[(CH 3 ) 2 NC(O)O-]benzyl, 3-chloro-4-[(4Xmethylpiperazin-r-yl)C(O)O-]benzyl, 3-chloro-4- [(4 X(pyridin-2-yl)piperazin- 1 ' -yl)C(O)O-]benzyl , 3-chloro-4- [(thiomorpholin-4 ' -yl)C(O)O-]benzy 1 , and 3-fluoro-4-[(CH 3 ) 2 NC(O)O-]benzyl. In another embodiment, R 5 is selected to form dimeric compounds of the formula: wherein each R 1 , R 2 and R 3 is as defined herein; Y is OH or R 6 , where R 6 is as defined herein; and A is a divalent group of the formula: -OC(O)N(R b )-R a -(R b )NC(O)O- or wherein each R a is independently selected from the group consisting of alkylene and substimted alkylene; each R b is independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, aryl, substimted aryl, cycloalkyl, substimted cyclalkyl, cycloalkenyl, substimted cycloalkenyl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic; and pharmaceutically acceptable salts thereof. Preferably, R a is ethylene (i.e., - H 2 H 2 -). In the compounds of formula IA, R 6 is preferably 2,4-dioxo- tetrahydrofuran-3-yl (3,4-enol), methoxy, ethoxy, rc-propoxy, isopropoxy, n- butoxy, t-butoxy, cyclopentoxy, cyclopropylmethoxy, neopentoxy, 2-α- isopropyl-4-β-methylcyclohexoxy, 2-β-isopropyl-4-β-methylcyclohexoxy, 2- methoxyphenoxy, 2-(morpholin-4-yl)ethoxy, -O(CH 2 CH 2 O) 2 CH 3 , 2- (phenoxy)ethoxy, -OCH 2 C(CH 3 ) 2 NHBoc, -NH 2 , benzyloxy, -NHCH 2 COOH, -NHCH 2 CH 2 COOH, -NH-adamantyl, -NHSO 2 -/?-CH 3 -φ, -NHCH 2 CH 2 COOCH 2 CH 3 , -NHOY' where Y' is hydrogen, methyl, iso- propyl or benzyl, O-(N-succinimidyl), -O-cholest-5-en-3-β-yl, -OCH 2 - OC(O)C(CH 3 ) 3 , -O(CH 2 ) 2 NHC(O)W where z is 1 or 2 and W is selected from the group consisting of pyrid-3-yl, N-methylpyridyl, and N-methyl-1,4- dihydro-pyrid-3-yl, -NR"C(O)-R' where R' is aryl, heteroaryl or heterocyclic and R" is hydrogen or -CH 2 C(O)OCH 2 CH 3 . Preferred compounds within the scope of formula I and IA above include by way of example: N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine n-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine cyclopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine n-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine cyclopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(isonipecotoyloxy)phenylalanine ethyl ester N-(α-toluenesulfonyl)-L-prolyl-L-4-(N- methylisonipecotoyloxy)phenylalanine ethyl ester N-( -toluenesulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-3-(N,N- dimethylcarbamyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(l-tert-butylcarbonyloxy-4- phenylpiperidin-4-ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-(5 ,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfony 1)-L- [( 1 , 1 -dioxo)thiamoφholin-3-carbonyl] -L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-[(l,l-dioxo)thiamoφholin-3-carbonyl]-L-4- (N,N-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(5 ,5-dimethyl)thiaprolyl-L-4-(4- methylpiperazin-l-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4- methy lpiperazin- 1 -y lcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)sarcosyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine N-( 1 -methy limidazole-4-sulfonyl)-L-proly l-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-aminobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(α-toluenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(piperazin-2-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-( -toluenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-adamantyl amide N-(toluene-4-sulfonyl)-L-ρrolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanylglycine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine methyl ester N-(toluene-4-sulfonyl)-L-(piperazin-2-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(4-benzyloxycarbonylpiperazin-2-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(isonipecotoyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-[(l,l-dioxo)thiamθφholin-3-carbonyl]-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-[(l ,l-dioxo)thiamθφholin-3-carbonyl]-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine N-(l-methylpyrazole-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxo-5,5-dimethyl)thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-( 1 -methylimidazole-4-sulfony l)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine 2-(saccharin-2-yl)propionoyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxo-5,5-dimethyl)thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(ρyridine-3-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-D-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-[(l,l-dioxo)thiamoφholin-3-carbonyl]-L-4- (N,N-dimethylaminosulfonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-N-methy lalany l-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(isonipecotoyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(pyrrolidin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine neopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine neopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-tert- butyloxycarbony lpiperazin- 1 -ylcarbonyloxy)pheny lalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine ethyl ester 2-(saccharin-2-yl)propionoyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester 2-(saccharin-2-yl)propionoyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)sarcosyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(l , l-dioxothiamoφholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(pyridine-3-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(pyrimidine-2-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)ρhenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l , l-dioxothiamoφholin-3-carbonyl)-L-4- (N,N-dimethylaminosulfonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l , 1 -dioxothiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-( 1 -methylpyrazole-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(piperazin-l- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfony l)-L-prolyl-L-4-( 1 -tert- butyloxycarbony lpiperazin- 1 -ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(piperazin- 1 - ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-acety lpiperazin- 1 - ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methanesulfonylpiperazin-l- ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4-ylcarbonyloxy)-3- nitrophenylalanine N-(toluene-4-sulfony l)-L-prolyl-L-4-( 1 -tert- butyloxycarbony lpiperazin- 1 -ylcarbonyloxy)pheny lalanine N-(toluene-4-sulfonyl)-L-N-methyl-2-(tert-butyl)glycinyl-L-4-(4- methy lpiperazin- 1-ylcarbony loxy )phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(l , l-dioxothiomoφholin-4-ylcarbonyloxy)pheny lalanine tert- butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (1 , l-dioxothiomoφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(l , 1 -dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(moφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-trifluoromethoxybenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester 3 - [N-(toluene-4-sulf ony l)-N-methy lamino] - 1 - [ 1 -tert-buty loxy carbony 1- 2-(N,N-dimethylcarbamyloxy)phenylethyl]azetidine N-(4-fluorobenzenesulfonyl)-L-(l,l-dioxo-5,5-dimethyl)thiaprolyl-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxo-5,5-dimethyl)thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3-carbonyl)-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(pyrimidine-2-sulfonyl)-L-proly l-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l ,l-dioxothiamoφholin-3-carbonyl)-L-4-(4- methy lpiperazin- 1-ylcarbony loxy )phenylalanine tert-butyl ester 3- [N-(toluene-4-sulfonyl)-N-methy lamino] - 1 - [ 1 -carboxy-2-(N,N- dimethylcarbamyloxy)phenylethyl]azetidine N-( 1 -methylpyrazole-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(isonipecotoyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(pyrrolidin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-( 1 , 1 -dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2,5-dichlorothiophene-3-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-acetamidobenzenesulfonyl)-L-prolyl-L-4-(N,N- di ethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-tert-butylbenzenesulfonyl)-L-(l , l-dioxothiamoφholin-3- carbonyl)-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(pyridine-2-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(2-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2,4-difluorobenzenesulfonyl)-L-(l , l-dioxothiamoφholin-3- carbonyl)-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-acetamidobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-trifluoromethoxybenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(3 , 3-dimethyl)ρrolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(3,3-dimethyl)ρrolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-( 1 -methylpyrazole-4-sulfonyl)-L-proly l-L-4-(N,N- dimethylcarbamyloxy)phenylalanine wo-propyl ester Ν-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l,4-dioxa-8-aza- spiro[4.5]decan-8-yl)carbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l,4-dioxa-8-aza- spiro[4.5]decan-8-yl)carbony loxy )pheny lalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -acety lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -methanesulfony lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-proly l-L-4-(4 ' -pheny lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-proly l-L-4-(piperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester 2-(saccharin-2-yl)propionyl-L-4-(4 ' -methy lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4'-methanesulfonylpiperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine (N -tert-butoxycarbonyl-2- amino-2-methylpropyl) ester N-(toluene-4-sulfonyl)-L-proly l-L-4-(4 ' -acety lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -hydroxypiperidin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -(moφholin-4x yl)ethyl)carbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l,4-dioxa-8-aza- spiro[4.5]decan-8-yl)carbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -hydroxyethyl)-N- methylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-4-(4 X(2-hydroxyethyl)piperazin- 1 - ylcarbonyloxy)-L-phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -formyloxyethyl)-N- methylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 X hydroxyethyl)-N- methylcarbamyloxy)phenylalanine isopropyl ester N-(toulene-4-sulfonyl)-L-prolyl-L-4-(N- (methoxycarbonylmethyl)carbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(4- N,N-dimethylcarbamy loxy )pheny lalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -methoxypiperidin- 1 - ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-proly l-L-4-(4 Xmethoxypiperidin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(N , N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-tra«5-4-hydroxyprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(moφholino-sulfonyl)-L-prolyl-L-(4-NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(moφholino-sulfonyl)-L-prolyl-L-(4-NN- dimethylcarbamyloxy)phenylalanine N-( 1 -methylpyrazole-4-sulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3- carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2-fluorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(2,4-difluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3- carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl-thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(N N-dimethylcarbamyloxy)phenylalanine N-( 1 -methylpyrazole-4-sulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 - carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(4-tert-butylbenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3- carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-(3,3-dimethyl)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(2,5-dichlorothiophene-3-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-methoxybenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-methoxybenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(l-oxo-thiomoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l-oxo-thiomoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-difluorobenzenesulfonyl)-L-prolyl-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-difluorobenzenesulfonyl)-L-prolyl-4-(NN- dimethylcarbamyloxy)phenylalanine N-(3 ,4-difluorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 - carbonyl)-L-4-(N N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-difluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3- carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine ethyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(pyridine-2-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(pyridine-2-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(pyridine-2-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(pyridine-2-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,5-difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2,4-difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2-chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-dichlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,5-dichlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-chlorobenzenesulfonyl)-L-(l , 1 -dioxothiamoφholin-3 -carbony 1)- L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-dichlorobenzenesulfonyl)-L-(l ,1 -dioxothiamoφholin-3- carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2-methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-dimethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2,4-difluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3 ,4-dichlorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 - carbonyl)-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(3-chlorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(3 -chloro-4-fluorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 - carbonyl)-L-4-(N N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-difluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)pheny lalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thioprolyl-L-(thiomoφholin-4- ylcarbonyloxy)phenylalanine isopropyl ester N-(3,4-difluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4- (N N-dimethylcarbamyloxy)phenylalanine N-(2,5-dichlorothiophene-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine isopropyl ester N-(8-quinolinesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(8-quinolinesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(8-quinolinesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isoproplyl ester N-(8-quinolinesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dirnethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-pheny lpiperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 x(ethoxycarbonyl)piperidin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3-sulfonamido-4-chloro-benzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfony l)-L-( 1 -oxothiomoφholin-3 -carbonyl)-L-4-(N N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2,4-difluorobenzenefulfonyl)-L-(l-oxothiomoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine 2,2-dimethylpropyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2,2-dimethylpropyl ester N-( 1 -methylpyrazole-4-sulfonyl)-L-(5 ,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamy loxy )pheny lalanine cyclopropylmethyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine methyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine ethyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine cyclopropylmethyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine 2-methoxyphenyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine «-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamy loxy )pheny lalanine n-propyl ester N-( 1 -methylpyrazole-4-sulfonyl)-L-(5 ,5-dimethyl)thiaprolyl-L-4- (N N-dimethylcarbamyloxy)phenylalanine 2,2- dimethylpropionyloxymethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(4'-(2'- aminoethyl)moφholino)carbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-[4-(carboxy)piperidin-l- ylcarbonyloxy]phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(NN-bis-(2- hydroxyethyl)carbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-[3-(hydroxymethyl)piperidin-l- ylcarbonyloxy]phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4- trifluoromethanesulfonylpiperazin-l-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-(N-phenylurea)benzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalamne tert-butyl ester N-(2-trifluoroacetyl-l,2,3,4-tetrahydroisoquinolin-7-sulfonyl)-L- prolyl-L-4-(N N-dimethylcarbamyloxy)pheny lalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(pyridine-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(pyridine-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(5 , 5 -dimethy l)thiaproly l-L-4-(N-methyl-N- (2-dimethylaminoethyl)carbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-methyl-Ν-(2- dimethylaminoethyl)carbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiapropyl-L-4-(N-methyl-N- (2-dimethylaminoethyl)carbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (4-methy lpiperazin- 1 -y lcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (NN-dimethycarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (N,N-dimethylcarbamyloxy)]phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (4-methy lpiperazin- 1 -ylcarbonyloxy)]pheny lalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-3-chloro-4-(N,N- dimethylcarbamyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (4-(2 ' -pyridyl)-piperazin- 1 -ylcarbonyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (4-(2'-pyridyl)-piperazin-l-ylcarbonyloxy)]pheny lalanine tert-butyl ester N-(4-nitrobenzenesulfonyl)-L-proly l-L-4-(N, N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-aminobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylcarbamylpiperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylcarbamylpiperazin-l- ylcarbonyloxy)phenylalanine N-(l-π-butylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (Ν,Ν-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(pyridin-4-ylcarbonyl)piperazin- l-ylcarbonyloxy)pheny lalanine isopropyl ester N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(Ν , N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-tratz5-4-hydroxyprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-aminobenzenesulfonyl)-L-proly l-L-4-(N N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4- [3 -(hydroxymethy l)piperidin- 1 - ylcarbonyloxy]phenylalanine N-(toluene-4-sulfonyl)-L-(4,4-difluoro)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(4,4-difluoro)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-(4-benzoy lpiperazin- 1 - ylcarbonyloxy)phenylalanine isopropyl ester N-(l -methyl- lH-imidazole-4-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-4-(thiomoφholin-4-ylcarbonyloxy)prolyl-L- 4-(thiomoφholin-4-ylcarbonyloxy)phenylalanine N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine isopropyl ester N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(N N- dimethylcarbamyloxy)phenylalanine methyl ester N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-4-hydroxyprolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-(4-benzoy lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine methyl ester N-(3-fluorobenzenesulfonyl)-L-prolyl-L-4-(N N- dimethylcarbanyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-[N-methyl-N-(2-(N-methyl-N- toluenesulfonyl-amino)ethyl)carbamyloxy]phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-[N-(2-(N- phenylaminocarbonyloxy)ethyl)carbamyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-4-(tran5-hydroxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-4-(tra«5-hydroxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine piperazine-1 ,4-dicarboxylic acid bis-{4-[(2S)-2-tert-butoxycarbonyl-2- ((4R)-5 ,5-dimethyl-3-(toluene-4-sulfonyl)thiazolidine-4- carboxamido)ethyl]phenyl} ester piperazine-1 ,4-dicarboxylic acid bis-{4-[(2S)-2-carboxy-2-((4R)-5,5- dimethyl-3-(toluene-4-sulfonyl)thiazolidine-4- carboxamido)ethyl]phenyl} ester N-(toluene-4-sulfonyl)-L-(pyrazin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(2- hydroxymethylpyrrolidin- 1 -ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(2- hydroxymethy lpyrrolidin- 1 -ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(2-methoxycarbonylpyrrolidin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine tert-butyl ester piperazine-1 ,4-dicarboxylic acid bis-{4-[(2S)-2-isopropoxycarbonyl-2- ((2R)-l-(toluene-4-sulfonyl)pyrrolidine-2-carboxamido)ethyl]phenyl} ester N-(toluene-4-sulfonyl)-L-(4-hydroxy)prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2-(2-methoxyethoxy)ethyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyrimidyl)piperazin- 1 -y lcarbonyloxy)]phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-fluoro-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(l -methanesulfony lpyrazin-3 -carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-[2-(l,l-dioxo-2,3-dihydro-3,3-dimethyl-l,2-benzisothiazol-2- yl)acetyl]-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-[2-(N-2, 10-camphorsultamyl)acetyl]-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-[2-(N-2, 10-camphorsultamyl)acetyl]-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-[2-(N-2, 10-camphorsultamyl)acetyl]-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(4-hydroxy)prolyl-L-4-(4-methylpiperazin-l- ylcarbony loxy )pheny lalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyrimidyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine piperazine- 1 ,4-dicarboxylic acid bis- {4-[(2S)-2-tert-butoxycarbonyl-2- ((2R)-l-(toluene-4-sulfonyl)pyrrolidine-2-carboxamido)ethyl]phenyl} ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(4-methylpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)]phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)]phenylalanine tert-butyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(N- phenylthiocarbonyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4- methylhomopiperazin-l-ylcarbonyloxy)phenylalanine tert-butyl ester piperazine-l,4-dicarboxylic acid bis-{4-[(2S)-2-carboxyl-2-((2R)-l- (toluene-4-sulfonyl)pyrrolidine-2-carboxamido)ethyl]phenyl } ester N-(toluene-4-sulfonyl)-L-4-(methanesulfonyloxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-aminocarbonylbenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-aminocarbonylbenzenesulfonyl)-L-prolyl-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)]phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (4-(2-pyridyl)piperazin-l-ylcarbonyloxy)]phenylalanine ethyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy)pheny lalanine N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4- methylhomopiperazin- 1 -ylcarbonyloxy)phenylalanine N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3- chloro-4-(NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)phenylalanine isopropyl ester N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin- 1 - ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l -methanesulfony lpyrazin-3 -carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-4-(methanesulfonyloxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(methanesulfonyl)-N-benzylglycinyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L- 4-(NN-dimethylcarbamyloxy)phenylalanine N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L- 4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L- 4-(4-(2-pyridyl)piperazin- 1 -ylcarbony loxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(4-hydroxy)prolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L- 4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine N-(l-methylimidazole-4-sulfonyl)-L-prolyl-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbony loxy )phenylalanine N-(l-methylimidazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4- (2-pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine N-( 1 -methylpyrazole-3-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine N-( 1 -methylpyrazole-3 -sulfonyl)-L-prolyl-L-4-(4-(2-pyridy l)piperazin- 1 -ylcarbonyloxy)phenylalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)phenylalanine tert-butyl ester N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-3-chloro-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)phenylalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2-phenoxyethyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3- chloro-4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3- chloro-4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine ethyl ester N-(3-chloro-l,5-dimethylpyrazole-3-sulfonyl)-L-(5,5- dimethyl)thiaprolyl-L-3-chloro-4-(4-(5-trifluoromethyl-2- pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine and pharmaceutically acceptable salts thereof as well as any of the ester compounds recited above wherein one ester is replaced with another ester selected from the group consisting of methyl ester, ethyl ester, «-propyl ester, isopropyl ester, n-butyl ester, isobutyl ester, sec-butyl ester, tert-butyl ester and neopentyl ester. This invention also provides methods for binding VLA-4 in a biological sample which method comprises contacting the biological sample with a compound of formula I or IA above under conditions wherein said compound binds to VLA-4. Certain of the compounds of formula I and IA above are also useful in reducing VLA-4 mediated inflammation in vivo. This invention also provides pharmaceutical compositions comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of one or more of the compounds of formula I or IA above with the exception that R 3 and R 5 are derived from L-amino acids or other similarly configured starting materials (alternatively racemic mixmres can be used). The pharmaceutical compositions may be used to treat VLA-4 mediated disease conditions. Such disease conditions include, by way of example, asthma, Alzheimer's disease, atherosclerosis, AIDS dementia, diabetes (including acute juvenile onset diabetis), inflammatory bowel disease (including ulcerative colitis and Crohn 's disease), multiple sclerosis, rheumatoid arthritis, tissue transplantation, mmor metastasis, meningitis, encephalitis, stroke, and other cerebral traumas, nephritis, retinitis, atopic dermatitis, psoriasis, myocardial ischemia and acute leukocyte-mediated lung injury such as that which occurs in adult respiratory distress syndrome. Accordingly, this invention also provides methods for the treatment of an inflammatory disease in a patient mediated by VLA-4 which methods comprise administering to the patient the pharmaceutical compositions described above. Preferred compounds of formula I and IA above include those set forth in Table I below: Table IA ■p t i- ^ 1- -P- 00 -P-. O o Ui t 00 O OS O σs t σs σ 00 ^1 O to -J w OS 00 VO 0o0 I 00 oo t oo 00 00 00 00 00 00 oo VO v O VO N V O o V VO σs O o 00 o o ot oaJ o O O t DETAILED DESCRIPTION OF THE INVENTION This invention relates to compounds which inhibit leukocyte adhesion and, in particular, leukocyte adhesion mediated by VLA-4. When describing the compounds, compositions and methods of this invention, the following terms have the following meanings, unless otherwise indicated. Definitions As used herein, "alkyl" refers to alkyl groups preferably having from 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms. This term is exemplified by groups such as methyl, t-butyl, n-heptyl, octyl and the like. "Substimted alkyl" refers to an alkyl group, preferably of from 1 to 10 carbon atoms, having from 1 to 5 substiments selected from the group consisting of alkoxy, substimted alkoxy, acyl, acylamino, thiocarbonylamino, acyloxy, amino, amidino, alkyl amidino, thioamidino, aminoacyl, aminocarbony lamino, aminothiocarbony lamino, aminocarbonyloxy, aryl, substimted aryl, aryloxy, substimted aryloxy, aryloxylaryl, substimted aryloxyaryl, cyano, halogen, hydroxyl, nitro, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl-cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl-substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheteroaryl, substimted thioheteroaryl, thioheterocyclic, substituted thioheterocyclic, heteroaryl, substituted aryl, substimted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substituted heterocyclyloxy, oxy carbony lamino, oxy thiocarbonylamino, -OS(O) 2 -alkyl, - OS(O) 2 -substituted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substituted aryl, -OS(O) 2 - heteroaryl, -OS(O) 2 -substimted heteroaryl, -OS(O) 2 -heterocyclic, -OS(O) 2 - substimted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substimted alkyl, -NRS(O) 2 -aryl, -NRS(O) 2 - substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substituted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substimted heterocyclic, -NRS(O) 2 -NR- alkyl, -NRS(O) 2 -NR-substimted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR- substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR-substituted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substimted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di-arylamino, mono- and di- substimted arylamino, mono- and di-heteroarylamino, mono- and di- substimted heteroarylamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substituted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substituted heteroaryl, heterocyclic and substimted heterocyclic and substimted alkyl groups having amino groups blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or alkyl/substituted alkyl groups substimted with -SC^-alkyl, - SO 2 -substituted alkyl, -SO 2 -alkenyl, -SO 2 -substituted alkenyl, -SO 2 - cycloalkyl, -SO 2 -substituted cycloalkyl, -SO 2 -aryl, -SO 2 -substituted aryl, - SO 2 -heteroaryl, -SO 2 -substituted heteroaryl, -SO 2 -heterocyclic, -SO 2 - substimted heterocyclic and -SO 2 NRR where R is hydrogen or alkyl. "Alkoxy" refers to the group "alkyl-O-" which includes, by way of example, methoxy, ethoxy, n-propoxy, Λsø-propoxy, n-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, and the like. "Substimted alkoxy" refers to the group "substimted alkyl-O-". "Acyl" refers to the groups H-C(O)-, alkyl-C(O)-, substimted alkyl- C(O)-, alkenyl-C(O)-, substimted alkenyl-C(O)-, alkynyl-C(O)-, substimted alkynyl-C(O)- cycloalkyl-C(O)-, substimted cycloalkyl-C(O)-, aryl-C(O)-, substimted aryl-C(O)-, heteroaryl-C(O)-, substimted heteroaryl-C(O), heterocyclic-C(O)-, and substimted heterocyclic-C(O)- wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Acylamino" refers to the group -C(O)NRR where each R is independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and where each R is joined to form together with the nitrogen atom a heterocyclic or substimted heterocyclic ring wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Thiocarbonylamino" refers to the group -C(S)NRR where each R is independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and where each R is joined to form, together with the nitrogen atom a heterocyclic or substimted heterocyclic ring wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substituted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Acyloxy" refers to the groups alkyl-C(O)O-, substimted alkyl- C(O)O-, alkenyl-C(O)O-, substimted alkenyl-C(O)O-, alkynyl-C(O)O-, substimted alkynyl-C(O)O-, aryl-C(O)O-, substimted aryl-C(O)O-, cycloalkyl-C(O)O-, substimted cycloalkyl-C(O)O-, heteroaryl-C(O)O-, substimted heteroaryl-C(O)O-, heterocyclic-C(O)O-, and substimted heterocyclic-C(O)O- wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Alkenyl" refers to alkenyl group preferably having from 2 to 10 carbon atoms and more preferably 2 to 6 carbon atoms and having at least 1 and preferably from 1-2 sites of alkenyl unsamration. "Substimted alkenyl" refers to alkenyl groups having from 1 to 5 substiments selected from the group consisting of alkoxy, substimted alkoxy, acyl, acylamino, thiocarbonylamino, acyloxy, amino, amidino, alkylamidino, thioamidino, aminoacyl, aminocarbonylamino, aminothiocarbony lamino, aminocarbonyloxy, aryl, substimted aryl, aryloxy, substimted aryloxy, aryloxyaryl, substimted aryloxyaryl, halogen, hydroxyl, cyano, nitro, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl- cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl- substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, cycloalkyl, substituted cycloalkyl, guanidino, guanidinosulfone, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheteroaryl, substimted thioheteroaryl, thioheterocyclic, substimted thioheterocyclic, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxycarbonylamino, oxy thiocarbonylamino, -OS(O) 2 -alkyl, -OS(O) 2 -substimted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substimted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substituted heteroaryl, -OS(O) 2 - heterocyclic, -OS(O) 2 -substituted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substituted alkyl, -NRS(O) 2 - aryl, -NRS(O) 2 -substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substimted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substituted heterocyclic, -NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substituted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR-substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR- substimted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substimted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di-arylamino, mono- and di- substimted arylamino, mono- and di-heteroary lamino, mono- and di- substimted heteroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and substimted alkenyl groups having amino groups blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or alkenyl/substituted alkenyl groups substimted with -SO 2 -alkyl, -SO 2 - substimted alkyl, -SO 2 -alkenyl, -SO 2 -substituted alkenyl, -SO 2 -cycloalkyl, -SO 2 -substimted cycloalkyl, -SO 2 -aryl, -SO 2 -substituted aryl, -SO 2 - heteroaryl, -SO 2 -substituted heteroaryl, -SO 2 -heterocyclic, -SO 2 -substituted heterocyclic and -SO 2 NRR where R is hydrogen or alkyl. "Alkynyl" refers to alkynyl group preferably having from 2 to 10 carbon atoms and more preferably 3 to 6 carbon atoms and having at least 1 and preferably from 1-2 sites of alkynyl unsamration. "Substimted alkynyl" refers to alkynyl groups having from 1 to 5 substiments selected from the group consisting of alkoxy, substimted alkoxy, acyl, acylamino, thiocarbonylamino, acyloxy, amino, amidino, alkylamidino, thioamidino, aminoacyl, aminocarbony lamino, aminothiocarbony lamino, aminocarbonyloxy, aryl, substimted aryl, aryloxy, substimted aryloxy, aryloxyaryl, substimted aryloxyaryl, halogen, hydroxyl, cyano, nitro, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl- cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl- substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheteroaryl, substimted thioheteroaryl, thioheterocyclic, substimted thioheterocyclic, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxy carbony lamino, oxy thiocarbonylamino, -OS(O) 2 -alkyl, -OS(O) 2 -substituted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substituted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substituted heteroaryl, -OS(O) 2 - heterocyclic, -OS(O) 2 -substituted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substituted alkyl, -NRS(O) 2 - aryl, -NRS(O) 2 -substituted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substituted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substituted heterocyclic, -NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substituted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR-substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR- substimted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substimted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di-ary lamino, mono- and di- substimted ary lamino, mono- and di-heteroary lamino, mono- and di- substimted heteroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substituted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and substimted alkynyl groups having amino groups blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or alkynyl/substituted alkynyl groups substituted with -SO 2 -alkyl, -SO 2 - substimted alkyl, -SO 2 -alkenyl, -SO 2 -substituted alkenyl, -SO 2 -cycloalkyl, -SO 2 -substimted cycloalkyl, -SO 2 -aryl, -SO 2 -substimted aryl, -SO 2 - heteroaryl, -SO 2 -substimted heteroaryl, -SO 2 -heterocyclic, -SO 2 -substimted heterocyclic and -SO 2 NRR where R is hydrogen or alkyl. "Alkylene" refers to a divalent alkylene group preferably having from 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms. This term is exemplified by groups such as methylene (-CH 2 -), ethylene (-CH 2 CH 2 -), the propylene isomers (e.g. , -CH 2 CH 2 CH 2 - and -CH(CH 3 )CH 2 -) and the like. "Substimted alkylene" refers to alkylene groups having from 1 to 5 substiments selected from the group consisting of alkoxy, substimted alkoxy, acyl, acylamino, thiocarbonylamino, acyloxy, amino, amidino, alkylamidino, thioamidino, aminoacyl, aminocarbony lamino, aminothiocarbony lamino, aminocarbony loxy, aryl, substimted aryl, aryloxy, substimted aryloxy, aryloxyaryl, substimted aryloxyaryl, halogen, hydroxyl, cyano, nitro, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl- cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl- substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheteroaryl, substituted thioheteroaryl, thioheterocyclic, substimted thioheterocyclic, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substituted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxycarbony lamino, oxy thiocarbonylamino, -OS(O) 2 -alkyl, -OS(O) 2 -substituted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substituted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substituted heteroaryl, -OS(O) 2 - heterocyclic, -OS(O) 2 -substimted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substimted alkyl, -NRS(O) 2 - aryl, -NRS(O) 2 -substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substimted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substimted heterocyclic, -NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substimted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR-substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR- substimted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substimted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substimted alkyl)amino, mono- and di-arylamino, mono- and di- substimted arylamino, mono- and di-heteroary lamino, mono- and di- substimted heteroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and substimted alkenyl groups having amino groups blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or alkenyl/ substimted alkenyl groups substimted with -SO 2 -alkyl, -SO 2 - substituted alkyl, -SO 2 -alkenyl, -SO 2 -substituted alkenyl, -SO 2 -cycloalkyl, -SO 2 -substituted cycloalkyl, -SO 2 -aryl, -SO 2 -substituted aryl, -SO 2 - heteroaryl, -SO 2 -substituted heteroaryl, -SO 2 -heterocyclic, -SO 2 -substituted heterocyclic and -SO 2 NRR where R is hydrogen or alkyl. "Amidino" refers to the group H 2 NC(=NH)- and the term "alkylamidino "refers to compounds having 1 to 3 alkyl groups (e.g., alkylHNC(=NH)-). "Thioamidino" refers to the group RSC(=NH)- where R is hydrogen or alkyl. "Aminoacyl" refers to the groups -NRC(O)alkyl, -NRC(O)substimted alkyl, -NRC(O)cycloalkyl, -NRC(O)substimted cycloalkyl, -NRC(O)alkenyl, -NRC(O)substituted alkenyl, -NRC(O)alkynyl, -NRC(O)substimted alkynyl, -NRC(O)aryl, -NRC(O)substimted aryl, -NRC(O)heteroaryl, -NRC(O)substituted heteroaryl, -NRC(O)heterocyclic, and -NRC(O)substimted heterocyclic where R is hydrogen or alkyl and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Aminocarbony loxy" refers to the groups -NRC(O)O-alkyl, -NRC(O)O-substituted alkyl, -NRC(O)O-alkenyl, -NRC(O)O-substituted alkenyl, -NRC(O)O-alkynyl, -NRC(O)O-substituted alkynyl, -NRC(O)O- cycloalkyl, -NRC(O)O-substituted cycloalkyl, -NRC(O)O-aryl, -NRC(O)O- substimted aryl, -NRC(O)O-heteroaryl, -NRC(O)O-substituted heteroaryl, -NRC(O)O-heterocyclic, and -NRC(O)O-substimted heterocyclic where R is hydrogen or alkyl and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Oxycarbonylamino" refers to the groups -OC(O)NH 2 , -OC(O)NRR, -OC(O)NR-alkyl, -OC(O)NR-substituted alkyl, -OC(O)NR-alkenyl, -OC(O)NR-substimted alkenyl, -OC(O)NR-alkynyl, -OC(O)NR-substituted alkynyl, -OC(O)NR-cycloalkyl, -OC(O)NR-substituted cycloalkyl, -OC(O)NR-aryl, -OC(O)NR-substimted aryl, -OC(O)NR-heteroaryl, -OC(O)NR-substituted heteroaryl,- OC(O)NR-heterocyclic, and -OC(O)NR-substimted heterocyclic where R is hydrogen, alkyl or where each R is joined to form, together with the nitrogen atom a heterocyclic or substimted heterocyclic ring and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Oxythiocarbonylamino" refers to the groups -OC(S)NH 2 , -OC(S)NRR, -OC(S)NR-alkyl, -OC(S)NR-substimted alkyl, -OC(S)NR- alkenyl, -OC(S)NR-substimted alkenyl, -OC(S)NR-alkynyl, -OC(S)NR- substimted alkynyl, -OC(S)NR-cycloalkyl, -OC(S)NR-substituted cycloalkyl, -OC(S)NR-aryl, -OC(S)NR-substimted aryl, -OC(S)NR-heteroaryl, - OC(S)NR-substimted heteroaryl, -OC(S)NR-heterocyclic, and -OC(S)NR-substimted heterocyclic where R is hydrogen, alkyl or where each R is joined to form together with the nitrogen atom a heterocyclic or substimted heterocyclic ring and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Aminocarbony lamino" refers to the groups -NRC(O)NRR, -NRC(O)NR-alkyl, -NRC(O)NR-substituted alkyl, -NRC(O)NR-alkenyl, -NRC(O)NR-substituted alkenyl, -NRC(O)NR-alkynyl, -NRC(O)NR-substimted alkynyl, -NRC(O)NR-aryl, -NRC(O)NR-substituted aryl, -NRC(O)NR-cycloalkyl, -NRC(O)NR-substituted cycloalkyl, - NRC(O)NR-heteroaryl, and -NRC(O)NR-substituted heteroaryl, - NRC(O)NR-heterocyclic, and -NRC(O)NR-substituted heterocyclic where each R is independently hydrogen, alkyl or where each R is joined to form together with the nitrogen atom a heterocyclic or substimted heterocyclic ring as well as where one of the amino groups is blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Aminothiocarbony lamino" refers to the groups -NRC(S)NRR, -NRC(S)NR-alkyl, -NRC(S)NR-substimted alkyl, -NRC(S)NR-alkenyl, -NRC(S)NR-substimted alkenyl, -NRC(S)NR-alkynyl, -NRC(S)NR- substimted alkynyl, -NRC(S)NR-aryl, -NRC(S)NR-substituted aryl, -NRC(S)NR-cycloalkyl, -NRC(S)NR-substituted cycloalkyl, -NRC(S)NR- heteroaryl, and -NRC(S)NR-substituted heteroaryl, -NRC(S)NR- heterocyclic, and -NRC(S)NR-substituted heterocyclic where each R is independently hydrogen, alkyl or where each R is joined to form together with the nitrogen atom a heterocyclic or substimted heterocyclic ring as well as where one of the amino groups is blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Aryl" or "Ar" refers to an unsaturated aromatic carbocyclic group of from 6 to 14 carbon atoms having a single ring (e.g. , phenyl) or multiple condensed rings (e.g. , naphthyl or anthryl) which condensed rings may or may not be aromatic (e.g., 2-benzoxazolinone, 2H-l,4-benzoxazin-3(4H)- one-7yl, and the like). Preferred aryls include phenyl and naphthyl. Substimted aryl refers to aryl groups which are substimted with from 1 to 3 substiments selected from the group consisting of hydroxy, acyl, acylamino, thiocarbonylamino, acyloxy, alkyl, substimted alkyl, alkoxy, substimted alkoxy, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, amidino, alkylamidino, thioamidino, amino, aminoacyl, aminocarbony loxy, aminocarbony lamino, ammothiocarbonylamino, aryl, substimted aryl, aryloxy, substituted aryloxy, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl-cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl- substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, carboxylamido, cyano, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thioheteroaryl, substimted thioheteroaryl, thiocycloalkyl, substituted thiocycloalkyl, thioheterocyclic, substimted thioheterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, halo, nitro, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxycarbonylamino, oxy thiocarbonylamino, -S(O) 2 -alkyl, -S(O) 2 -substituted alkyl, -S(O) 2 - cycloalkyl, -S(O) 2 -substituted cycloalkyl, -S(O) 2 -alkenyl, -S(O) 2 -substituted alkenyl, -S(O) 2 -aryl, -S(O) 2 -substituted aryl, -S(O) 2 -heteroaryl, -S(O) 2 - substimted heteroaryl, -S(O) 2 -heterocyclic, -S(O) 2 -substituted heterocyclic, - OS(O) 2 -alkyl, -OS(O) 2 -substimted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substimted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substituted heteroaryl, -OS(O) 2 - heterocyclic, -OS(O) 2 -substimted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substimted alkyl, -NRS(O) 2 - aryl, -NRS(O) 2 -substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substimted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substimted heterocyclic, - NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substimted alkyl, -NRS(O) 2 -NR-aryl, - NRS(O) 2 -NR-substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR- substituted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substituted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di-ary lamino, mono- and di- substimted ary lamino, mono- and di-heteroary lamino, mono- and di- substimted heteroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic and amino groups on the substimted aryl blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or substimted with -SO 2 NRR where R is hydrogen or alkyl. "Aryloxy" refers to the group aryl-O- which includes, by way of example, phenoxy, naphthoxy, and the like. "Substimted aryloxy" refers to substimted aryl-O- groups. "Aryloxyaryl" refers to the group -aryl-O-aryl. "Substimted aryloxyaryl" refers to aryloxyaryl groups substituted with from 1 to 3 substiments on either or both aryl rings selected from the group consisting of hydroxy, acyl, acylamino, thiocarbonylamino, acyloxy, alkyl, substimted alkyl, alkoxy, substimted alkoxy, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, amidino, alkylamidino, thioamidino, amino, aminoacyl, aminocarbonyloxy, aminocarbony lamino, aminothiocarbonylamino, aryl, substimted aryl, aryloxy, substimted aryloxy, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substituted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl-cycloalkyl, carboxyl- substimted cycloalkyl, carboxylaryl, carboxyl-substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, carboxylamido, cyano, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thioheteroaryl, substimted thioheteroaryl, thiocycloalkyl, substituted thiocycloalkyl, thioheterocyclic, substimted thioheterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, halo, nitro, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substituted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxycarbonylamino, oxy thiocarbonylamino, -S(O) 2 -alkyl, -S(O) 2 -substituted alkyl, -S(O) 2 -cycloalkyl, -S(O) 2 -substimted cycloalkyl, -S(O) 2 -alkenyl, -S(O) 2 -substimted alkenyl, -S(O) 2 -aryl, -S(O) 2 - substimted aryl, -S(O) 2 -heteroaryl, -S(O) 2 -substituted heteroaryl, -S(O) 2 - heterocyclic, -S(O) 2 -substimted heterocyclic, -OS(O) 2 -alkyl, -OS(O) 2 - substimted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substituted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substimted heteroaryl, -OS(O) 2 -heterocyclic, -OS(O) 2 -substimted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substituted alkyl, -NRS(O) 2 -aryl, -NRS(O) 2 - substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substimted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substimted heterocyclic, -NRS(O) 2 -NR- alkyl, -NRS(O) 2 -NR-substimted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR- substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR-substimted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substimted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di-arylamino, mono- and di- substimted ary lamino, mono- and di-heteroary lamino, mono- and di- substimted heteroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic and amino groups on the substimted aryl blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or substimted with -SO 2 NRR where R is hydrogen or alkyl. "Cycloalkyl" refers to cyclic alkyl groups of from 3 to 8 carbon atoms having a single cyclic ring including, by way of example, cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl and the like. Excluded from this definition are multi-ring alkyl groups such as adamantanyl, etc. "Cycloalkenyl" refers to cyclic alkenyl groups of frm 3 to 8 carbon atoms having a single cyclic ring. " Substimted cycloalkyl" and "substimted cycloalkenyl" refers to an cycloalkyl or cycloalkenyl group, preferably of from 3 to 8 carbon atoms, having from 1 to 5 substiments selected from the group consisting of oxo (=O), thioxo (=S), alkoxy, substimted alkoxy, acyl, acylamino, thiocarbonylamino, acyloxy, amino, amidino, alkylamidino, thioamidino, aminoacyl, aminocarbony lamino, aminothiocarbonylamino, aminocarbony loxy, aryl, substimted aryl, aryloxy, substimted aryloxy, aryloxyaryl, substimted aryloxyaryl, halogen, hydroxyl, cyano, nitro, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl-cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl-substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheteroaryl, substimted thioheteroaryl, thioheterocyclic, substimted thioheterocyclic, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxy carbony lamino, oxy thiocarbonylamino, -OS(O) 2 -alkyl, -OS(O) 2 - substimted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substituted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substituted heteroaryl, -OS(O) 2 -heterocyclic, -OS(O) 2 -substituted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substituted alkyl, -NRS(O) 2 -aryl, -NRS(O) 2 - substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substituted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 -substituted heterocyclic, -NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substituted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR-substituted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR- substituted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substituted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di-ary lamino, mono- and di- substimted ary lamino, mono- and di-heteroary lamino, mono- and di- substituted he teroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic and substimted alkynyl groups having amino groups blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or alkynyl/substituted alkynyl groups substimted with -S - alkyl, -SO 2 -substituted alkyl, -SO 2 -alkenyl, -SO 2 -substituted alkenyl, -SO 2 - cycloalkyl, -SO 2 -substituted cycloalkyl, -SO 2 -aryl, -SO 2 -substituted aryl, - SO 2 -heteroaryl, -SO 2 -substituted heteroaryl, -SO 2 -heterocyclic, -SO 2 - substimted heterocyclic and -SO 2 NRR where R is hydrogen or alkyl. "Cycloalkoxy" refers to -O-cycloalkyl groups. "Substimted cycloalkoxy" refers to -O-substimted cycloalkyl groups. "Guanidino" refers to the groups -NRC(=NR)NRR, -NRC(=NR)NR-alkyl, -NRC(=NR)NR-substituted alkyl, -NRC(=NR)NR- alkenyl, -NRC(=NR)NR-substituted alkenyl, -NRC(=NR)NR-alkynyl, -NRC(=NR)NR-substimted alkynyl, -NRC(=NR)NR-aryl, -NRC( = NR)NR-substituted aryl , -NRC( = NR)NR-cycloalkyl , -NRC(=NR)NR-heteroaryl, -NRC(=NR)NR-substimted heteroaryl, -NRC(=NR)NR-heterocyclic, and -NRC(=NR)NR-substimted heterocyclic where each R is independently hydrogen and alkyl as well as where one of the amino groups is blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substituted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "N,N-Dimethylcarbamyloxy" refers to the group -OC(O)Ν(CH 3 ) 2 . " Guanidinosulfone" refers to the groups -NRC(=NR)NRSO 2 -alkyl, -NRC( = NR)NRSO 2 -substimted alkyl, -NRC(=NR)NRSO 2 -alkenyl, -NRC(=NR)NRSO 2 -substimted alkenyl, -NRC(=NR)NRSO 2 -alkynyl, -NRC(=NR)NRSO 2 -substimted alkynyl, -NRC(=NR)NRSO 2 -aryl, -NRC(=NR)NRSO 2 -substimted aryl, -NRC(=NR)NRSO 2 -cycloalkyl, -NRC(=NR)NRSO 2 -substimted cycloalkyl, -NRC(=NR)NRSO 2 -heteroaryl, and -NRC(=NR)NRSO 2 -substituted heteroaryl, -NRC(=NR)NRSO 2 - heterocyclic, and -NRC(=NR)NRSO 2 -substituted heterocyclic where each R is independently hydrogen and alkyl and wherein alkyl, substimted alkyl, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic are as defined herein. "Halo" or "halogen" refers to fluoro, chloro, bromo and iodo and preferably is either chloro or bromo. "Heteroaryl" refers to an aromatic carbocyclic group of from 2 to 10 carbon atoms and 1 to 4 heteroatoms selected from the group consisting of oxygen, nitrogen and sulfur within the ring. Such heteroaryl groups can have a single ring (e.g. , pyridyl or furyl) or multiple condensed rings (e.g., indolizinyl or benzothienyl). Preferred heteroaryls include pyridyl, pyrrolyl, indolyl and furyl. "Substimted heteroaryl" refers to heteroaryl groups which are substimted with from 1 to 3 substiments selected from the group consisting of hydroxy, acyl, acylamino, thiocarbonylamino, acyloxy, alkyl, substimted alkyl, alkoxy, substituted alkoxy, alkenyl, substimted alkenyl, alkynyl, substimted alkynyl, amidino, alkylamidino, thioamidino, amino, aminoacyl, aminocarbony loxy, aminocarbony lamino, aminothiocarbonylamino, aryl, substimted aryl, aryloxy, substimted aryloxy, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl-cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl-substimted aryl, carboxylheteroaryl, carboxyl-substimted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, carboxylamido, cyano, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thioheteroaryl, substimted thioheteroaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheterocyclic, substimted thioheterocyclic, cycloalkyl, substimted cycloalkyl, guanidino, guanidinosulfone, halo, nitro, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, heterocyclyloxy, substimted heterocyclyloxy, oxycarbony lamino, oxy thiocarbonylamino, -S(O) 2 -alkyl, -S(O) 2 -substituted alkyl, -S(O) 2 -cycloalkyl, -S(O) 2 -substituted cycloalkyl, -S(O) 2 -alkenyl, -S(O) 2 -substituted alkenyl, -S(O) 2 -aryl, -S(O) 2 -substituted aryl, -S(O) 2 -heteroaryl, -S(O) 2 -substituted heteroaryl, -S(O) 2 -heterocyclic, -S(O) 2 -substituted heterocyclic, -OS(O) 2 -alkyl, -OS(O) 2 -substituted alkyl, -OS(O) 2 -aryl, -OS(O) 2 -substimted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 - substimted heteroaryl, -OS(O) 2 -heterocyclic, -OS(O) 2 -substituted heterocyclic, -OSO 2 -NRR where R is hydrogen or alkyl, -NRS(O) 2 -alkyl, -NRS(O) 2 -substimted alkyl, -NRS(O) 2 -aryl, -NRS(O) 2 -substimted aryl, -NRS(O) 2 -heteroaryl, -NRS(O) 2 -substimted heteroaryl, -NRS(O) 2 - heterocyclic, -NRS(O) 2 -substituted heterocyclic, -NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substimted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR- substimted aryl, -NRS(O) 2 -NR-heteroaryl, -NRS(O) 2 -NR-substimted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substituted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substimted alkyl)amino, mono- and di-arylamino, mono- and di- substimted ary lamino, mono- and di-heteroary lamino, mono- and di- substimted heteroary lamino, mono- and di-heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substituted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic and amino groups on the substimted aryl blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or substimted with -SO 2 NRR where R is hydrogen or alkyl. "Heteroaryloxy" refers to the group -O-heteroaryl and "substimted heteroaryloxy" refers to the group -O-substimted heteroaryl. "Heterocycle" or "heterocyclic" refers to a samrated or unsaturated group having a single ring or multiple condensed rings, from 1 to 10 carbon atoms and from 1 to 4 hetero atoms selected from the group consisting of nitrogen, sulfur or oxygen within the ring wherein, in fused ring systems, one or more the rings can be aryl or heteroaryl. "Substimted heterocyclic" refers to heterocycle groups which are substimted with from 1 to 3 substiments selected from the group consisting of oxo (=O), thioxo (=S), alkoxy, substimted alkoxy, acyl, acylamino, thiocarbonylamino, acyloxy, amino, amidino, alkylamidino, thioamidino, aminoacyl, aminocarbony lamino, aminothiocarbonylamino, aminocarbony loxy, aryl, substimted aryl, aryloxy, substimted aryloxy, aryloxyaryl, substimted aryloxyaryl, halogen, hydroxyl, cyano, nitro, carboxyl, carboxylalkyl, carboxyl-substimted alkyl, carboxyl-cycloalkyl, carboxyl-substimted cycloalkyl, carboxylaryl, carboxyl-substimted aryl, carboxylheteroaryl, carboxyl-substituted heteroaryl, carboxylheterocyclic, carboxyl-substimted heterocyclic, cycloalkyl, substituted cycloalkyl, guanidino, guanidinosulfone, thiol, thioalkyl, substimted thioalkyl, thioaryl, substimted thioaryl, thiocycloalkyl, substimted thiocycloalkyl, thioheteroaryl, substimted thioheteroaryl, thioheterocyclic, substimted thioheterocyclic, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic, cycloalkoxy, substimted cycloalkoxy, heteroaryloxy, substimted heteroaryloxy, -C(O)O-aryl, -C(O)O-substituted aryl, heterocyclyloxy, substimted heterocyclyloxy, oxycarbony lamino, oxy thiocarbonylamino, -OS(O) 2 -alkyl, -OS(O) 2 -substimted alkyl, -OS(O) 2 - aryl, -OS(O) 2 -substimted aryl, -OS(O) 2 -heteroaryl, -OS(O) 2 -substimted heteroaryl, -OS(O) 2 -heterocyclic, -OS(O) 2 -substimted heterocyclic, -OSO 2 - NRR where R is hydrogen or alkyl, -NRS^-alkyl, -NRS(O) 2 -substituted alkyl, -NRS(O) 2 -aryl, -NRS(O) 2 -substimted aryl, -NRS(O) 2 -heteroaryl, - NRS(O) 2 -substimted heteroaryl, -NRS(O) 2 -heterocyclic, -NRS(O) 2 - substituted heterocyclic, -NRS(O) 2 -NR-alkyl, -NRS(O) 2 -NR-substituted alkyl, -NRS(O) 2 -NR-aryl, -NRS(O) 2 -NR-substimted aryl, -NRS(O) 2 -NR- heteroaryl, -NRS(O) 2 -NR-substimted heteroaryl, -NRS(O) 2 -NR-heterocyclic, -NRS(O) 2 -NR-substimted heterocyclic where R is hydrogen or alkyl, mono- and di-alkylamino, mono- and di-(substituted alkyl)amino, mono- and di- arylamino, mono- and di-substimted arylamino, mono- and di- heteroary lamino, mono- and di-substimted heteroary lamino, mono- and di- heterocyclic amino, mono- and di-substimted heterocyclic amino, unsymmetric di-substimted amines having different substiments selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heteroaryl, substituted heteroaryl, heterocyclic and substimted heterocyclic and substimted alkynyl groups having amino groups blocked by conventional blocking groups such as Boc, Cbz, formyl, and the like or alkynyl/substituted alkynyl groups substimted with -SO 2 -alkyl, -SO 2 - substituted alkyl, -SO 2 -alkenyl, -SO 2 -substituted alkenyl, -SO 2 -cycloalkyl, - SO 2 -substituted cycloalkyl, -SO 2 -aryl, -SO 2 -substituted aryl, -SO 2 -heteroaryl, -SO 2 -substituted heteroaryl, -SO 2 -heterocyclic, -SO 2 -substituted heterocyclic and -SO 2 NRR where R is hydrogen or alkyl. Examples of heterocycles and heteroaryls include, but are not limited to, azetidine, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, indole, dihydroindole, indazole, purine, quinolizine, isoquinoline, quinoline, phthalazine, naphthylpyridine, quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, phenanthroline, isothiazole, phenazine, isoxazole, phenoxazine, phenothiazine, imidazolidine, imidazoline, piperidine, piperazine, indoline, phthalimide, 1,2,3,4-tetrahydroisoquinoline, 4,5,6,7- tetrahydrobenzo[b]thiophene, thiazole, thiazolidine, thiophene, benzo[b] thiophene, moφholinyl, thiomoφholinyl (also referred to as thiamoφholinyl), piperidinyl, pyrrolidine, tetrahydrofuranyl, and the like. "Heterocyclyloxy" refers to the group -O-heterocyclic and "substimted heterocyclyloxy" refers to the group -O-substimted heterocyclic. "Thiol" refers to the group -SH. "Thioalkyl" refers to the groups -S-alkyl "Substimted thioalkyl" refers to the group -S-substimted alkyl. "Thiocycloalkyl" refers to the groups -S-cycloalkyl. "Substimted thiocycloalkyl" refers to the group -S-substituted cycloalkyl. "Thioaryl" refers to the group -S-aryl and "substimted thioaryl" refers to the group -S-substituted aryl. "Thioheteroaryl" refers to the group -S-heteroaryl and "substimted thioheteroaryl" refers to the group -S-substituted heteroaryl. "Thioheterocyclic" refers to the group -S-heterocyclic and "substimted thioheterocyclic" refers to the group -S-substituted heterocyclic. " Pharmaceutically acceptable salt" refers to pharmaceutically acceptable salts of a compound of Formula I/IA which salts are derived from a variety of organic and inorganic counter ions well known in the art and include, by way of example only, sodium, potassium, calcium, magnesium, ammonium, tetraalkylammomum, and the like; and when the molecule contains a basic functionality, salts of organic or inorganic acids, such as hydrochloride, hydrobromide, tartrate, mesylate, acetate, maleate, oxalate and the like. Compound Preparation The compounds of this invention can be prepared from readily available starting materials using the following general methods and procedures. It will be appreciated that where typical or preferred process conditions (i.e., reaction temperatures, times, mole ratios of reactants, solvents, pressures, etc.) are given, other process conditions can also be used unless otherwise stated. Optimum reaction conditions may vary with the particular reactants or solvent used, but such conditions can be determined by one skilled in the art by routine optimization procedures. Additionally, as will be apparent to those skilled in the art, conventional protecting groups may be necessary to prevent certain functional groups from undergoing undesired reactions. Suitable protecting groups for various functional groups as well as suitable conditions for protecting and deprotecting particular functional groups are well known in the art. For example, numerous protecting groups are described in T. W. Greene and G. M. Wuts, Protecting Groups in Organic Synthesis, Second Edition, Wiley, New York, 1991, and references cited therein. Furthermore, the compounds of this invention will typically contain one or more chiral centers. Accordingly, if desired, such compounds can be prepared or isolated as pure stereoisomers, i.e., as individual enantiomers or diastereomers, or as stereoisomer-enriched mixmres. All such stereoisomers (and enriched mixmres) are included within the scope of this invention, unless otherwise indicated. Pure stereoisomers (or enriched mixmres) may be prepared using, for example, optically active starting materials or stereoselective reagents well-known in the art. Alternatively, racemic mixmres of such compounds can be separated using, for example, chiral column chromatography, chiral resolving agents and the like. In a preferred method of synthesis, the compounds of formula I and I A wherein Q is -C(O)NR 7 - are prepared by first coupling an amino acid of formula II: wherein R 2 and R3 are as defined herein (e.g., in formula I and IIA), with a sulfonyl chloride of formula III: O II R 1 -S— Cl HI II O wherein R 1 is as defined herein, to provide an N-sulfonyl amino acid of formula IV: O i i I R 1 -S-Ν-CH-COOH TV I I I 1 V o R 2 wherein R ! -R 3 are as defined herein. This reaction is typically conducted by reacting the amino acid of formula II with at least one equivalent, preferably about 1.1 to about 2 equivalents, of sulfonyl chloride III in an inert diluent such as dichloromethane and the like. Generally, the reaction is conducted at a temperamre ranging from about -70 °C to about 40 °C for about 1 to about 24 hours. Preferably, this reaction is conducted in the presence of a suitable base to scavenge the acid generated during the reaction. Suitable bases include, by way of example, tertiary amines, such as triethylamine, diisopropylethylamme, N-methylmoφholine and the like. Alternatively, the reaction can be conducted under Schotten-Baumann-type conditions using aqueous alkali, such as sodium hydroxide and the like, as the base. Upon completion of the reaction, the resulting N-sulfonyl amino acid IV is recovered by conventional methods including neutralization, extraction, precipitation, chromatography, filtration, and the like. The amino acids of formula II employed in the above reaction are either known compounds or compounds that can be prepared from known compounds by conventional synthetic procedures. Examples of suitable amino acids for use in this reaction include, but are not limited to, L-proline, trøns-4-hydroxyl-L-proline, c/.ϊ-4-hydroxyl-L-proline, tra«5-3-phenyl-L- proline, s-3-phenyl-L-proline, L-(2-mefhyl)proline, L-pipecolinic acid, L- azetidine-2-carboxylic acid, L-indoline-2-carboxylic acid, L-1,2,3,4- tetrahydroisoquinoline-3 -carboxylic acid, L-thiazolidine-4-carboxylic acid, L-(5 ,5-dimethyl)thiazolidine-4-carboxylic acid, L-thiamoφholine-3- carboxylic acid, glycine, 2-tert-butylglycine, D,L-phenylglycine, L-alanine, α-methylalanine, N-methyl-L-pheny lalanine, L-dipheny lalanine, sarcosine, D,L-phenylsarcosine, L-aspartic acid β-tert-butyl ester, L-glutamic acid γ- tert-butyl ester, L-(t9-benzyl)serine, 1-aminocyclopropanecarboxylic acid, 1- aminocyclobutanecarboxylic acid, 1-aminocyclopentanecarboxylic acid (cycloleucine) 1-aminocyclohexanecarboxylic acid, L-serine and the like. If desired, the corresponding carboxylic acid esters of the amino acids of formula II, such as the methyl esters, ethyl esters and the like, can be employed in the above reaction with the sulfonyl chloride III. Subsequent hydrolysis of the ester group to the carboxylic acid using conventional reagents and conditions, i.e., treatment with an alkali metal hydroxide in an inert diluent such as methanol/water, then provides the N-sulfonyl amino acid IV. Similarly, the sulfonyl chlorides of formula III employed in the above reaction are either known compounds or compounds that can be prepared from known compounds by conventional synthetic procedures. Such compounds are typically prepared from the corresponding sulfonic acid, i.e., from compounds of the formula R 1 -SO 3 H where R 1 is as defined above, using phosphorous trichloride and phosphorous pentachloride. This reaction is generally conducted by contacting the sulfonic acid with about 2 to 5 molar equivalents of phosphorous trichloride and phosphorous pentachloride, either neat or in an inert solvent, such as dichloromethane, at temperamre in the range of about 0°C to about 80 °C for about 1 to about 48 hours to afford the sulfonyl chloride. Alternatively, the sulfonyl chlorides of formula III can be prepared from the corresponding thiol compound, i.e., from compounds of the formula R^SH where R 1 is as defined herein, by treating the thiol with chlorine (Cl 2 ) and water under conventional reaction conditions. Examples of sulfonyl chlorides suitable for use in this invention include, but are not limited to, methanesulfony 1 chloride, 2-propanesulfonyl chloride, 1-butanesulfonyl chloride, benzenesulfonyl chloride, 1- naphthalenesulfonyl chloride, 2-naphthalenesulfonyl chloride, p- toluenesulfonyl chloride, -toluenesulfonyl chloride, 4- acetamidobenzenesulfonyl chloride, 4-amidinobenzenesulfonyl chloride, 4- rert-butylbenzenesulfonyl chloride, 4-bromobenzenesulfonyl chloride, 2- carboxybenzenesulfonyl chloride, 4-cyanobenzenesulfonyl chloride, 3,4- dichlorobenzenesulfonyl chloride, 3,5-dichlorobenzenesulfonyl chloride, 3,4- dimethoxybenzenesulfonyl chloride , 3 ,5-ditrifluoromethylbenzenesulfonyl chloride, 4-fluorobenzenesulfonyl chloride, 4-methoxybenzenesulfonyl chloride, 2-methoxy carbony lbenzenesulf ony 1 chloride, 4- methylamidobenzenesulfonyl chloride, 4-nitrobenzenesulfonyl chloride, 4- thioamidobenzenesulfonyl chloride, 4-trifluoromethy lbenzenesulf ony 1 chloride, 4-trifluoromethoxybenzenesulfonyl chloride, 2,4,6- trimethylbenzenesulfonyl chloride, 2-phenylethanesulfonyl chloride, 2- thiophenesulfonyl chloride, 5-chloro-2-thiophenesulfonyl chloride, 2,5- dichloro-4-thiophenesulfonyl chloride, 2-thiazolesulfonyl chloride, 2-methyl- 4-thiazolesulfonyl chloride, 1 -methy 1-4-imidazolesulfonyl chloride, 1- methyl-4-pyrazolesulfonyl chloride, 5 -chloro- 1,3 -dimethy 1-4- pyrazolesulfonyl chloride, 3-pyridinesulfonyl chloride, 2-pyrimidinesulfonyl chloride and the like. If desired, a sulfonyl fluoride, sulfonyl bromide or sulfonic acid anhydride may be used in place of the sulfonyl chloride in the above reaction to form the N-sulfonyl amino acids of formula IV. The intermediate N-sulfonyl amino acids of formula IV can also be prepared by reacting a sulfonamide of formula V: O II R 1 -S-Ν-R2 II H O wherein R 1 and R 2 are as defined herein, with a carboxylic acid derivative of the formula L(R 3 )CHCOOR where L is a leaving group, such as chloro, bromo, iodo, mesylate, tosylate and the like, R 3 is as defined herein and R is hydrogen or an alkyl group. This reaction is typically conducted by contacting the sulfonamide V with at least one equivalent, preferably 1.1 to 2 equivalents, of the carboxylic acid derivative in the presence of a suitable base, such as triethylamine, in an inert diluent, such as DMF, at a temperamre ranging from about 24 °C to about 37 °C for about 0.5 to about 4 hours. This reaction is further described in Zuckermann et al. , J. Am. Chem. Soc , 1992, 114, 10646-10647. Preferred carboxylic acid derivatives for use in this reaction are α-chloro and α-bromocarboxylic acid esters such as tert-butyl bromoacetate and the like. When a carboxylic acid ester is employed in this reaction, the ester group is subsequently hydrolyzed using conventional procedures to afford an N-sulfonyl amino acid of formula IV. The compounds of formula I/IA are then prepared by coupling the intermediate N-sulfonyl amino acid of formula IV with an amino acid derivative of formula VI: wherein R 5 -R 7 are as defined herein. This coupling reaction is typically conducted using well-known coupling reagents such as carbodiimides, BOP reagent (benzotriazol- 1 -y loxy-tris(dimethylamino)phosphonium hexafluorophosphonate) and the like. Suitable carbodiimides include, by way of example, dicyclohexylcarbodiimide (DCC), l-(3-dimethylamino- propyl)-3-ethylcarbodiimide (EDC) and the like. If desired, polymer supported forms of carbodumide coupling reagents may also be used including, for example, those described in Tetrahedron Letters, 34(48), 7685 (1993). Additionally, well-known coupling promoters, such as N- hydroxysuccinimide, 1-hydroxybenzotriazole and the like, may be used to facilitate the coupling reaction. This coupling reaction is typically conducted by contacting the N- sulfonylamino acid IV with about 1 to about 2 equivalents of the coupling reagent and at least one equivalent, preferably about 1 to about 1.2 equivalents, of amino acid derivative VI in an inert diluent, such as dichloromethane, chloroform, acetonitrile, tetrahydrofuran, N,N- dimethylformamide and the like. Generally, this reaction is conducted at a temperamre ranging from about 0°C to about 37°C for about 12 to about 24 hours. Upon completion of the reaction, the compound of formula I/IA is recovered by conventional methods including neutralization, extraction, precipitation, chromatography, filtration, and the like. Alternatively, the N-sulfonyl amino acid IV can be converted into an acid halide and the acid halide coupled with amino acid derivative VI to provide compounds of formula I/IA. The acid halide of VI can be prepared by contacting VI with an inorganic acid halide, such as thionyl chloride, phosphorous trichloride, phosphorous tribromide or phosphorous pentachloride, or preferably, with oxalyl chloride under conventional conditions. Generally, this reaction is conducted using about 1 to 5 molar equivalents of the inorganic acid halide or oxalyl chloride, either neat or in an inert solvent, such as dichloromethane or carbon tetrachloride, at temperamre in the range of about 0°C to about 80°C for about 1 to about 48 hours. A catalyst, such as DMF, may also be used in this reaction. The acid halide of N-sulfonyl amino acid IV is then contacted with at least one equivalent, preferably about 1.1 to about 1.5 equivalents, of amino acid derivative VI in an inert diluent, such as dichloromethane, at a temperamre ranging from about -70 °C to about 40 °C for about 1 to about 24 hours. Preferably, this reaction is conducted in the presence of a suitable base to scavenge the acid generated during the reaction. Suitable bases include, by way of example, tertiary amines, such as triethylamine, diisopropylethylamme, N-methylmoφholine and the like. Alternatively, the reaction can be conducted under Schotten-Baumann-type conditions using aqueous alkali, such as sodium hydroxide and the like. Upon completion of the reaction, the compound of formula I/IA is recovered by conventional methods including neutralization, extraction, precipitation, chromatography, filtration, and the like. Alternatively, the compounds of formula I/IA can be prepared by first forming a diamino acid derivative of formula VII: wherein R 2 , R 3 , R 5 , R 6 and R 7 are as defined herein. The diamino acid derivatives of formula VII can be readily prepared by coupling an amino acid of formula II with an amino acid derivative of formula VI using conventional amino acid coupling techniques and reagents, such carbodiimides, BOP reagent and the like, as described above. Diamino acid VII can then be sulfonated using a sulfonyl chloride of formula III and using the synthetic procedures described above to provide a compound of formula I/IA. The amino acid derivatives of formula VI employed in the above reactions are either known compounds or compounds that can be prepared from known compounds by conventional synthetic procedures. For example, amino acid derivatives of formula VI can be prepared by C- alkylating commercially available diethyl 2-acetamidomalonate (Aldrich, Milwaukee, Wisconsin, USA) with an alkyl or substimted alkyl halide. This reaction is typically conducted by treating the diethyl 2-acetamidomalonate with at least one equivalent of sodium ethoxide and at least one equivalent of an alkyl or substituted alkyl halide in refluxing ethanol for about 6 to about 12 hours. The resulting C-alkylated malonate is then deacetylated, hydrolyzed and decarboxylated by heating in aqueous hydrochloric acid at reflux for about 6 to about 12 hours to provide the amino acid, typically as the hydrochloride salt. Examples of amino acid derivatives of formula VI suitable for use in the above reactions include, but are not limited to, L-tyrosine methyl ester, L-3,5-diiodotyrosine methyl ester, L-3-iodotyrosine methyl ester, β-(4- hydroxy-naphth-l-yl)-L-alanine methyl ester, β-(6-hydroxy-naphth-2-yl)-L- alanine methyl ester, and the like. If desired, of course, other esters or amides of the above-described compounds may also be employed. For ease of synthesis, the compounds of formula I are typically prepared as an ester, i.e., where R 6 is an alkoxy or substimted alkoxy group and the like. If desired, the ester group can be hydrolysed using conventional conditions and reagents to provide the corresponding carboxylic acid. Typically, this reaction is conducted by treating the ester with at least one equivalent of an alkali metal hydroxide, such as lithium, sodium or potassium hydroxide, in an inert diluent, such as methanol or mixmres of methanol and water, at a temperamre ranging about 0°C to about 24°C for about 1 to about 10 hours. Alternatively, benzyl esters may be removed by hydrogenolysis using a palladium catalyst, such as palladium on carbon. The resulting carboxylic acids may be coupled, if desired, to amines such as β-alanine ethyl ester, hydroxyamines such as hydroxylamine and N- hydroxysuccinimide, alkoxyamines and substimted alkoxyamines such as O- methylhydroxylamine and O-benzylhydroxylamine, and the like, using conventional coupling reagents and conditions as described above. As will be apparent to those skilled in the art, other functional groups present on any of the substiments of the compounds of formula I can be readily modified or derivatized either before or after the above-described coupling reactions using well-known synthetic procedures. For example, a nitro group present on a substiment of a compound of formula I/IA or an intermediate thereof may be readily reduced by hydrogenation in the presence of a palladium catalyst, such as palladium on carbon, to provide the corresponding amino group. This reaction is typically conducted at a temperamre of from about 20 °C to about 50 °C for about 6 to about 24 hours in an inert diluent, such as methanol. Compounds having a nitro group on, e.g., the R 3 substiment, can be prepared, for example, by using a 4- nitrophenylalanine derivative and the like in the above-described coupling reactions. Similarly, a pyridyl group can be hydrogenated in the presence of a platinum catalyst, such as platinum oxide, in an acidic diluent to provide the corresponding piperidinyl analogue. Generally, this reaction is conducted by treating the pyridine compound with hydrogen at a pressure ranging from about 20 psi to about 60 psi, preferably about 40 psi, in the presence of the catalyst at a temperamre of about 20°C to about 50°C for about 2 to about 24 hours in an acidic diluent, such as a mixmre of methanol and aqueous hydrochloric acid. Compounds having a pyridyl group can be readily prepared by using, for example, β-(2-pyridyl)-, β-(3-pyridyl)- or β-(4- pyridyl)-L-alanine derivatives in the above-described coupling reactions. Additionally, when a substiment of a compound of formula I/IA or an intermediate thereof contains a primary or secondary amino group, such amino groups can be further derivatized either before or after the above coupling reactions to provide, by way of example, amides, sulfonamides, ureas, thioureas, carbamates, secondary or tertiary amines and the like. Compounds having a primary amino group on such a substiment may be prepared, for example, by reduction of the corresponding nitro compound as described above. Alternatively, such compounds can be prepared by using an amino acid derivative of formula VI derived from lysine, 4- aminophenylalanine and the like in the above-described coupling reactions. By way of illustration, a compound of formula I/IA or an intermediate thereof having a substiment containing a primary or secondary amino group can be readily N-acylated using conventional acylating reagents and conditions to provide the corresponding amide. This acylation reaction is typically conducted by treating the amino compound with at least one equivalent, preferably about 1.1 to about 1.2 equivalents, of a carboxylic acid in the presence of a coupling reagent such as a carbodumide, BOP reagent (benzotriazol- 1 -yloxy-tris(dimethylamino)-phosphonium hexafluorophosphonate) and the like, in an inert diluent, such as dichloromethane, chloroform, acetonitrile, tetrahydrofuran, N,N- dimethylformamide and the like, at a temperamre ranging from about 0°C to about 37 °C for about 4 to about 24 hours. Preferably, a promoter, such as N-hydroxysuccinimide, 1 -hydroxy benzotriazole and the like, is used to facilitate the acylation reaction. Examples of carboxylic acids suitable for use in this reaction include, but are not limited to, N-tert- buty loxycarbonylglycine , N-tert-buty loxycarbonyl-L-phenylalanine , N-tert- butyloxycarbonyl-L-aspartic acid benzyl ester, benzoic acid, N-tert- butyloxycarbonylisonipecotic acid, N-methylisonipecotic acid, N-tert- buty loxy carbony lnipecotic acid, N-tert-buty loxy carbony 1-L- tetrahydroisoquinoline-3-carboxylic acid, N-(toluene-4-sulfonyl)-L-proline and the like. Alternatively, a compound of formula I/IA or an intermediate thereof containing a primary or secondary amino group can be N-acylated using an acyl halide or a carboxylic acid anhydride to form the corresponding amide. This reaction is typically conducted by contacting the amino compound with at least one equivalent, preferably about 1.1 to about 1.2 equivalents, of the acyl halide or carboxylic acid anhydride in an inert diluent, such as dichloromethane, at a temperamre ranging from about of about -70 °C to about 40°C for about 1 to about 24 hours. If desired, an acylation catalyst such as 4-(N,N-dirnethylamino)pyridine may be used to promote the acylation reaction. The acylation reaction is preferably conducted in the presence of a suitable base to scavenge the acid generated during the reaction. Suitable bases include, by way of example, tertiary amines, such as triethylamine, diisopropylethylamine, N-methylmoφholine and the like. Alternatively, the reaction can be conducted under Schotten-Baumann-type conditions using aqueous alkali, such as sodium hydroxide and the like. Examples of acyl halides and carboxylic acid anhydrides suitable for use in this reaction include, but are not limited to, 2-methylpropionyl chloride, trimethylacetyl chloride, phenylacetyl chloride, benzoyl chloride, 2-bromobenzoyl chloride, 2-methylbenzoyl chloride, 2- trifluoromethylbenzoyl chloride, isonicotinoyl chloride, nicotinoyl chloride, picolinoyl chloride, acetic anhydride, succinic anhydride and the like. Carbamyl chlorides, such as N,N-dimethylcarbamyl chloride, N,N- diethylcarbamyl chloride and the like, can also be used in this reaction to provide ureas. Similarly, dicarbonates, such as di-tert-butyl dicarbonate, may be employed to provide carbamates. In a similar manner, a compound of formula I/IA or an intermediate thereof containing a primary or secondary amino group may be N-sulfonated to form a sulfonamide using a sulfonyl halide or a sulfonic acid anhydride. Sulfonyl halides and sulfonic acid anhydrides suitable for use in this reaction include, but are not limited to, methanesulfonyl chloride, chloromethanesulfonyl chloride, p-tofuenesulfonyl chloride, trifluoromethanesulfonic anhydride and the like. Similarly, sulfamoyl chlorides, such as dimethylsulfamoyl chloride, can be used to provide sulfamides (e.g. , > Ν-SO 2 -Ν < ). Additionally, a primary and secondary amino group present on a substiment of a compound of formula I/IA or an intermediate thereof can be reacted with an isocyanate or a thioisocyanate to give a urea or thiourea, respectively. This reaction is typically conducted by contacting the amino compound with at least one equivalent, preferably about 1.1 to about 1.2 equivalents, of the isocyanate or thioisocyanate in an inert diluent, such as toluene and the like, at a temperamre ranging from about 24 °C to about 37 °C for about 12 to about 24 hours. The isocyanates and thioisocyanates used in this reaction are commercially available or can be prepared from commercially available compounds using well-known synthetic procedures. For example, isocyanates and thioisocyanates are readily prepared by reacting the appropriate amine with phosgene or thiophosgene. Examples of isocyanates and thioisocyanates suitable for use in this reaction include, but are not limited to, ethyl isocyanate, n-propyl isocyanate, 4-cyanophenyl isocyanate, 3-methoxyphenyl isocyanate, 2-phenylethyl isocyanate, methyl thioisocyanate, ethyl thioisocyanate, 2-phenylethyl thioisocyanate, 3- phenylpropyl thioisocyanate, 3-(N,N-diethylamino)propyl thioisocyanate, phenyl thioisocyanate, benzyl thioisocyanate, 3 -pyridyl thioisocyanate, fluorescein isothiocyanate (isomer I), and the like. Furthermore, when a compound of formula I/IA or an intermediate thereof contains a primary or secondary amino group, the amino group can be reductively alkylated using aldehydes or ketones to form a secondary or tertiary amino group. This reaction is typically conducted by contacting the amino compound with at least one equivalent, preferably about 1.1 to about 1.5 equivalents, of an aldehyde or ketone and at least one equivalent based on the amino compound of a metal hydride reducing agent, such as sodium cyanoborohydride, in an inert diluent, such as methanol, tetrahydromran, mixtures thereof and the like, at a temperamre ranging from about 0°C to about 50 °C for about 1 to about 72 hours. Aldehydes and ketones suitable for use in this reaction include, by way of example, benzaldehyde, 4- chlorobenzaldehyde, valeraldehyde and the like. In a similar manner, when a compound of formula I/IA or an intermediate thereof has a substiment containing a hydroxyl group, the hydroxyl group can be further modified or derivatized either before or after the above coupling reactions to provide, by way of example, ethers, carbamates and the like. Compounds having a hydroxyl group on the R 5 substiment, for example, can be prepared using an amino acid derivative of formula VI derived from tyrosine and the like in the above-described reactions. By way of example, a compound of formula I/IA or an intermediate thereof having a substiment containing a hydroxyl group can be readily 0-alkylated to form ethers. This (9-alkylation reaction is typically conducted by contacting the hydroxy compound with a suitable alkali or alkaline earth metal base, such as potassium carbonate, in an inert diluent, such as acetone, 2-butanone and the like, to form the alkali or alkaline earth metal salt of the hydroxyl group. This salt is generally not isolated, but is reacted in situ with at least one equivalent of an alkyl or substimted alkyl halide or sulfonate, such as an alkyl chloride, bromide, iodide, mesylate or tosylate, to afford the ether. Generally, this reaction is conducted at a temperamre ranging from about 60 °C to about 150°C for about 24 to about 72 hours. Preferably, a catalytic amount of sodium or potassium iodide is added to the reaction mixmre when an alkyl chloride or bromide is employed in the reaction. Examples of alkyl or substimted alkyl halides and sulfonates suitable for use in this reaction include, but are not limited to, tert-butyl bromoacetate, N-tert-buty 1 chloroacetamide, 1-bromoethylbenzene, ethyl α- bromophenylacetate, 2-(N-ethyl-N-phenylamino)ethyl chloride, 2-(N,N- ethylamino)ethyl chloride, 2-(N,N-diisopropylamino)ethyl chloride, 2-(N,N- dibenzylamino)ethyl chloride, 3-(N,N-ethylamino)propyl chloride, 3-(N- benzyl-N-methylamino)propyl chloride, N-(2-chloroethyl)moφholine, 2- (hexamethyleneimino)ethyl chloride, 3-(N-methylpiperazine)propyl chloride, 1 -(3-chlorophenyl)-4-(3-chloropropyl)piperazine , 2-(4-hydroxy-4- phenylpiperidine)ethyl chloride, N-tert-butyloxycarbonyl-3-piperidinemethyl tosylate and the like. Alternatively, a hydroxyl group present on a substiment of a compound of formula I/IA or an intermediate thereof can be -alkylating using the Mitsunobu reaction. In this reaction, an alcohol, such as 3-(N,N- dimethylamino)-l-propanol and the like, is reacted with about 1.0 to about 1.3 equivalents of triphenylphosphine and about 1.0 to about 1.3 equivalents of diethyl azodicarboxylate in an inert diluent, such as tetrahydrofuran, at a temperamre ranging from about -10°C to about 5°C for about 0.25 to about 1 hour. About 1.0 to about 1.3 equivalents of a hydroxy compound, such as N-tert-buty ltyrosine methyl ester, is then added and the reaction mixmre is stirred at a temperamre of about 0°C to about 30 °C for about 2 to about 48 hours to provide the Oalkylated product. In a similar manner, a compound of formula I/IA or an intermediate thereof containing a aryl hydroxy group can be reacted with an aryl iodide to provide a diaryl ether. Generally, this reaction is conducted by forming the alkali metal salt of the hydroxyl group using a suitable base, such as sodium hydride, in an inert diluent such as xylenes at a temperamre of about -25 °C to about 10 °C. The salt is then treated with about 1.1 to about 1.5 equivalents of cuprous bromide dimethyl sulfide complex at a temperamre ranging from about 10 °C to about 30 °C for about 0.5 to about 2.0 hours, followed by about 1.1 to about 1.5 equivalents of an aryl iodide, such as sodium 2-iodobenzoate and the like. The reaction is then heated to about 70 °C to about 150°C for about 2 to about 24 hours to provide the diaryl ether. Additionally, a hydroxy-containing compound can also be readily derivatized to form a carbamate. In one method for preparing such carbamates, a hydroxy compound of formula I/IA or an intermediate thereof is contacted with about 1.0 to about 1.2 equivalents of 4-nitrophenyl chloroformate in an inert diluent, such as dichloromethane, at a temperature ranging from about -25 °C to about 0°C for about 0.5 to about 2.0 hours. Treatment of the resulting carbonate with an excess, preferably about 2 to about 5 equivalents, of a trialkylamine, such as triethylamine, for about 0.5 to 2 hours, followed by about 1.0 to about 1.5 equivalents of a primary or secondary amine provides the carbamate. Examples of amines suitable for using in this reaction include, but are not limited to, piperazine, 1- methylpiperazine, 1 -acety lpiperazine, moφholine, thiomoφholine, pyrrolidine, piperidine and the like. Alternatively, in another method for preparing carbamates, a hydroxy-containing compound is contacted with about 1.0 to about 1.5 equivalents of a carbamyl chloride in an inert diluent, such as dichloromethane, at a temperamre ranging from about 25 °C to about 70 °C for about 2 to about 72 hours. Typically, this reaction is conducted in the presence of a suitable base to scavenge the acid generated during the reaction. Suitable bases include, by way of example, tertiary amines, such as triethylamine, diisopropylethylamine, N-methylmoφholine and the like. Additionally, at least one equivalent (based on the hydroxy compound) of 4- (NN-dimethylamino)pyridine is preferably added to the reaction mixture to facilitate the reaction. Examples of carbamyl chlorides suitable for use in this reaction include, by way of example, dimethylcarbamyl chloride, diethylcarbamyl chloride and the like. Likewise, when a compound of formula I/IA or an intermediate thereof contains a primary or secondary hydroxyl group, such hydroxyl groups can be readily converted into a leaving group and displaced to form, for example, amines, sulfides and fluorides. For example, derivatives of 4- hydroxy-L-proline can be converted into the corresponding 4-amino, 4-thio or 4-fluoro-L-proline derivatives via nucleophilic displacement of the derivatized hydroxyl group. Generally, when a chiral compound is employed in these reactions, the stereochemistry at the carbon atom attached to the derivatized hydroxyl group is typically inverted. These reactions are typically conducted by first converting the hydroxyl group into a leaving group, such as a tosylate, by treatment of the hydroxy compound with at least one equivalent of a sulfonyl halide, such as p-toluenesulfonyl chloride and the like, in pyridine. This reaction is generally conducted at a temperamre of from about 0°C to about 70 °C for about 1 to about 48 hours. The resulting tosylate can then be readily displaced with sodium azide, for example, by contacting the tosylate with at least one equivalent of sodium azide in an inert diluent, such as a mixmre of N,N-dimethylformamide and water, at a temperamre ranging from about 0°C to about 37 °C for about 1 to about 12 hours to provide the corresponding azido compound. The azido group can then be reduced by, for example, hydrogenation using a palladium on carbon catalyst to provide the amino (- ΝH 2 ) compound. Similarly, a tosylate group can be readily displaced by a thiol to form a sulfide. This reaction is typically conducted by contacting the tosylate with at least one equivalent of a thiol, such as thiophenol, in the presence of a suitable base, such as l,8-diazabicyclo[5.4.0]undec-7-ene (DBU), in an inert diluent, such as N,N-dimethylformamide, at a temperamre of from about 0°C to about 37 °C for about 1 to about 12 hours to provide the sulfide. Additionally, treatment of a tosylate with moφholinosulfur trifluoride in an inert diluent, such as dichloromethane, at a temperamre ranging from about 0°C to about 37°C for about 12 to about 24 hours affords the corresponding fluoro compound. Furthermore, a compound of formula I/IA or an intermediate thereof having a substiment containing an iodoaryl group, for example, when R 5 is a (4-iodophenyl)methyl group, can be readily converted either before or after the above coupling reactions into a biaryl compound. Typically, this reaction is conducted by treating the iodoaryl compound with about 1.1 to about 2 equivalents of an arylzinc iodide, such as 2- (methoxycarbonyOphenylzinc iodide, in the presence of a palladium catalyst, such as palladium tetra(triphenylphosphine), in an inert diluent, such as tetrahydrofuran, at a temperature ranging from about 24°C to about 30°C until the reaction is complete. This reaction is further described, for example, in Rieke, J. Org. Chem. 1991, 56, 1445. In some cases, the compounds of formula I/IA or intermediates thereof may contain substiments having one or more sulfur atoms. Such sulfur atoms will be present, for example, when the amino acid of formula II employed in the above reactions is derived from L-thiazolidine-4-carboxylic acid, L-(5,5-dimethyl)thiazolidine-4-carboxylic acid, L-thiamoφholine-3- carboxylic acid and the like. When present, such sulfur atoms can be oxidized either before or after the above coupling reactions to provide a sulfoxide or sulfone compound using conventional reagents and reaction conditions. Suitable reagents for oxidizing a sulfide compound to a sulfoxide include, by way of example, hydrogen peroxide, 3-chloroperoxybenzoic acid (MCPBA), sodium periodate and the like. The oxidation reaction is typically conducted by contacting the sulfide compound with about 0.95 to about 1.1 equivalents of the oxidizing reagent in an inert diluent, such as dichloromethane, at a temperamre ranging from about -50 °C to about 75 °C for about 1 to about 24 hours. The resulting sulfoxide can then be further oxidized to the corresponding sulfone by contacting the sulfoxide with at least one additional equivalent of an oxidizing reagent, such as hydrogen peroxide, MCPBA, potassium permanganate and the like. Alternatively, the sulfone can be prepared directly by contacting the sulfide with at least two equivalents, and preferably an excess, of the oxidizing reagent. Such reactions are described further in March, "Advanced Organic Chemistry", 4th Ed., pp. 1202-1202, Wiley Publishers, (1992). As described above, the compounds of formula I/IA having an R 2 substiment other an hydrogen can be prepared using an N-substituted amino acid of formula II, such as sarcosine, N-methyl-L-pheny lalanine and the like, in the above-described coupling reactions. Alternatively, such compounds can be prepared by N-alkylation of a sulfonamide of formula I or IV (where R 2 is hydrogen) using conventional synthetic procedures. Typically, this N- alkylation reaction is conducted by contacting the sulfonamide with at least one equivalent, preferably 1.1 to 2 equivalents, of an alkyl or substimted alkyl halide in the presence of a suitable base, such as potassium carbonate, in an inert diluent, such as acetone, 2-butanone and the like, at a temperamre ranging from about 25 °C to about 70 °C for about 2 to about 48 hours. Examples of alkyl or substimted alkyl halides suitable for use in this reaction include, but are not limited to, methyl iodide, and the like. Additionally, the sulfonamides of formula I or IV wherein R 2 is hydrogen and R 1 is a 2-alkoxycarbonylaryl group can be intramolecularly cyclized to form l,2-benzisothiazol-3-one derivatives or analogues thereof. This reaction is typically conducted by treating a sulfonamide, such as N-(2- methoxycarbonylphenylsulfonyOglycine-L-phenylalanine benzyl ester, with about 1.0 to 1.5 equivalents of a suitable base, such as an alkali metal hydride, in a inert diluent, such as tetrahydrofuran, at a temperamre ranging from about 0°C to about 30 °C for about 2 to about 48 hours to afford the cyclized 1 ,2-benzisothiazol-3-one derivative. Lastly, the compounds of formula I where Q is -C(S)ΝR 7 - are prepared by using an amino thionoacid derivative in place of amino acid II in the above described synthetic procedures. Such amino thionoacid derivatives can be prepared by the procedures described in Shalaky, et al. , J. Org. Chem., 61:9045-9048 (1996) and Brain, et al. , J. Org. Chem., 62: 3808- 3809 (1997) and references cited therein. Pharmaceutical Formulations When employed as pharmaceuticals, the compounds of formula I and I A are usually administered in the form of pharmaceutical compositions. These compounds can be administered by a variety of routes including oral, rectal, transdermal, subcutaneous, intravenous, intramuscular, and intranasal. These compounds are effective as both injectable and oral compositions. Such compositions are prepared in a manner well known in the pharmaceutical art and comprise at least one active compound. This invention also includes pharmaceutical compositions which contain, as the active ingredient, one or more of the compounds of formula I and I A above associated with pharmaceutically acceptable carriers. In making the compositions of this invention, the active ingredient is usually mixed with an excipient, diluted by an excipient or enclosed within such a carrier which can be in the form of a capsule, sachet, paper or other container. When the excipient serves as a diluent, it can be a solid, semi- solid, or liquid material, which acts as a vehicle, carrier or medium for the active ingredient. Thus, the compositions can be in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as a solid or in a liquid medium), ointments containing, for example, up to 10% by weight of the active compound, soft and hard gelatin capsules, suppositories, sterile injectable solutions, and sterile packaged powders. In preparing a formulation, it may be necessary to mill the active compound to provide the appropriate particle size prior to combining with the other ingredients. If the active compound is substantially insoluble, it ordinarily is milled to a particle size of less than 200 mesh. If the active compound is substantially water soluble, the particle size is normally adjusted by milling to provide a substantially uniform distribution in the formulation, e.g. about 40 mesh. Some examples of suitable excipients include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, and methyl cellulose. The formulations can additionally include: lubricating agents such as talc, magnesium stearate, and mineral oil; wetting agents; emulsifying and suspending agents; preserving agents such as methyl- and propylhydroxy- benzoates; sweetening agents; and flavoring agents. The compositions of the invention can be formulated so as to provide quick, sustained or delayed release of the active ingredient after administration to the patient by employing procedures known in the art. The compositions are preferably formulated in a unit dosage form, each dosage containing from about 5 to about 100 mg, more usually about 10 to about 30 mg, of the active ingredient. The term "unit dosage forms" refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical excipient. The active compound is effective over a wide dosage range and is generally administered in a pharmaceutically effective amount. It, will be understood, however, that the amount of the compound actually administered will be determined by a physician, in the light of the relevant circumstances, including the condition to be treated, the chosen route of administration, the acmal compound administered, the age, weight, and response of the individual patient, the severity of the patient's symptoms, and the like. For preparing solid compositions such as tablets, the principal active ingredient is mixed with a pharmaceutical excipient to form a solid preformulation composition containing a homogeneous mixmre of a compound of the present invention. When referring to these preformulation compositions as homogeneous, it is meant that the active ingredient is dispersed evenly throughout the composition so that the composition may be readily subdivided into equally effective unit dosage forms such as tablets, pills and capsules. This solid preformulation is then subdivided into unit dosage forms of the type described above containing from, for example, 0.1 to about 500 mg of the active ingredient of the present invention. The tablets or pills of the present invention may be coated or otherwise compounded to provide a dosage form affording the advantage of prolonged action. For example, the tablet or pill can comprise an inner dosage and an outer dosage component, the latter being in the form of an envelope over the former. The two components can separated by an enteric layer which serves to resist disintegration in the stomach and permit the inner component to pass intact into the duodenum or to be delayed in release. A variety of materials can be used for such enteric layers or coatings, such materials including a number of polymeric acids and mixmres of polymeric acids with such materials as shellac, cetyl alcohol, and cellulose acetate. The liquid forms in which the novel compositions of the present invention may be incoφorated for administration orally or by injection include aqueous solutions suitably flavored syrups, aqueous or oil suspensions, and flavored emulsions with edible oils such as cottonseed oil, sesame oil, coconut oil, or peanut oil, as well as elixirs and similar pharmaceutical vehicles. Compositions for inhalation or insufflation include solutions and suspensions in pharmaceutically acceptable, aqueous or organic solvents, or mixmres thereof, and powders. The liquid or solid compositions may contain suitable pharmaceutically acceptable excipients as described supra. Preferably the compositions are administered by the oral or nasal respiratory route for local or systemic effect. Compositions in preferably pharmaceutically acceptable solvents may be nebulized by use of inert gases. Nebulized solutions may be breathed directly from the nebulizing device or the nebulizing device may be attached to a face masks tent, or intermittent positive pressure breathing machine. Solution, suspension, or powder compositions may be administered, preferably orally or nasally, from devices which deliver the formulation in an appropriate manner. The following formulation examples illustrate the pharmaceutical compositions of the present invention. Formulation Example 1 Hard gelatin capsules containing the following ingredients are prepared: Quantity Ingredient (mg/capsule) Active Ingredient 30.0 Starch 305.0 Magnesium stearate 5.0 The above ingredients are mixed and filled into hard gelatin capsules in 340 mg quantities. Formulation Example 2 A tablet formula is prepared using the ingredients below: Quantity Ingredient (mg/tablet) Active Ingredient 25.0 Cellulose, microcrystalline 200.0 Colloidal silicon dioxide 10.0 Stearic acid 5.0 The components are blended and compressed to form tablets, each weighing 240 mg. Formulation Example 3 A dry powder inhaler formulation is prepared containing the following components: Ingredient Weight % Active Ingredient 5 Lactose 95 The active mixmre is mixed with the lactose and the mixmre is added to a dry powder inhaling appliance. Formulation Example 4 Tablets, each contaimng 30 mg of active ingredient, are prepared as follows: Quantity Ingredient (mg/tablet) Active Ingredient 30.0 mg Starch 45.0 mg Microcrystalline cellulose 35.0 mg Polyvinylpyrrolidone (as 10% solution in water) 4.0 mg Sodium carboxymethyl starch 4.5 mg Magnesium stearate 0.5 mg Talc 1.0 mg Total 120 mg The active ingredient, starch and cellulose are passed through a No. 20 mesh U.S. sieve and mixed thoroughly. The solution of polyvinyl- pyrrolidone is mixed with the resultant powders, which are then passed through a 16 mesh U.S. sieve. The granules so produced are dried at 50° to 60 °C and passed through a 16 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate, and talc, previously passed through a No. 30 mesh U.S. sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets each weighing 150 mg. Formulation Example 5 Capsules, each containing 40 mg of medicament are made as follows: Quantity Ingredient (mg/capsule) Active Ingredient 40.0 mg Starch 109.0 mg Magnesium stearate 1.0 mg Total 150.0 mg The active ingredient, cellulose, starch, an magnesium stearate are blended, passed through a No. 20 mesh U.S. sieve, and filled into hard gelatin capsules in 150 mg quantities. Formulation Example 6 Suppositories, each containing 25 mg of active ingredient are made as follows: Ingredient Amount Active Ingredient 25 mg Samrated fatty acid glycerides to 2,000 mg The active ingredient is passed through a No. 60 mesh U.S. sieve and suspended in the samrated fatty acid glycerides previously melted using the minimum heat necessary. The mixmre is then poured into a suppository mold of nominal 2.0 g capacity and allowed to cool. Formulation Example 7 Suspensions, each containing 50 mg of medicament per 5.0 ml dose are made as follows: Ingredient Amount Active Ingredient 50.0 mg Xanthan gum 4.0 mg Sodium carboxymethyl cellulose (11 %) Microcrystalline cellulose (89%) 50.0 mg Sucrose 1.75 g Sodium benzoate 10.0 mg Flavor and Color q.v. Purified water to 5.0 ml The medicament, sucrose and xanthan gum are blended, passed through a No. 10 mesh U.S. sieve, and then mixed with a previously made solution of the microcrystalline cellulose and sodium carboxymethyl cellulose in water. The sodium benzoate, flavor, and color are diluted with some of the water and added with stirring. Sufficient water is then added to produce the required volume. Formulation Example 8 Quantity Ingredient (mg/capsule) Active Ingredient 15.0 mg Starch 407.0 mg Magnesium stearate 3.0 mg Total 425.0 mg The active ingredient, cellulose, starch, and magnesium stearate are blended, passed through a No. 20 mesh U.S. sieve, and filled into hard gelatin capsules in 560 mg quantities. Formulation Example 9 An intravenous formulation may be prepared as follows: Ingredient Quantity Active Ingredient 250.0 mg Isotonic saline 1000 mL Formulation Example 10 A topical formulation may be prepared as follows: Ingredient Quantity Active Ingredient 1-10 g Emulsifying Wax 30 g Liquid Paraffin 20 g White Soft Paraffin to 100 g The white soft paraffin is heated until molten. The liquid paraffin and emulsifying wax are incoφorated and stirred until dissolved. The active ingredient is added and stirring is continued until dispersed. The mixmre is then cooled until solid. Another preferred formulation employed in the methods of the present invention employs transdermal delivery devices ("patches"). Such transdermal patches may be used to provide continuous or discontinuous infusion of the compounds of the present invention in controlled amounts. The construction and use of transdermal patches for the delivery of pharmaceutical agents is well known in the art. See, e.g., U.S. Patent 5,023,252, issued June 11, 1991, which is incoφorated herein by reference in its entirety. Such patches may be constructed for continuous, pulsatile, or on demand delivery of pharmaceutical agents. When it is desirable or necessary to introduce the pharmaceutical composition to the brain, either direct or indirect techniques may be employed. Direct techniques usually involve placement of a drug delivery catheter into the host's ventricular system to bypass the blood-brain barrier. One such implantable delivery system used for the transport of biological factors to specific anatomical regions of the body is described in U.S. Patent 5,011,472 which is incoφorated herein by reference in its entirety. Indirect techniques, which are generally preferred, usually involve formulating the compositions to provide for drug latentiation by the conversion of hydrophilic drugs into lipid-soluble drugs. Latentiation is generally achieved through blocking of the hydroxy, carbonyl, sulfate, and primary amine groups present on the drug to render the drug more lipid soluble and amenable to transportation across the blood-brain barrier. Alternatively, the delivery of hydrophilic drugs may be enhanced by intra-arterial infusion of hypertonic solutions which can transiently open the blood-brain barrier. Utility The compounds of this invention can be employed to bind VLA-4 integrin) in biological samples and, accordingly have utility in, for example, assaying such samples for VLA-4. In such assays, the compounds can be bound to a solid support and the VLA-4 sample added thereto. The amount of VLA-4 in the sample can be determined by conventional methods such as use of a sandwich ELISA assay. Alternatively, labeled VLA-4 can be used in a competitive assay to measure for the presence of VLA-4 in the sample. Other suitable assays are well known in the art. In addition, certain of the compounds of this invention inhibit, in vivo, adhesion of leukocytes to endothelial cells mediated by VLA-4 and, accordingly, can be used in the treatment of diseases mediated by VLA-4. Such diseases include inflammatory diseases in mammalian patients such as asthma, Alzheimer's disease, atherosclerosis, AIDS dementia, diabetes (including acute juvenile onset diabetes), inflammatory bowel disease (including ulcerative colitis and Crohn 's disease), multiple sclerosis, rheumatoid arthritis, tissue transplantation, mmor metastasis, meningitis, encephalitis, stroke, and other cerebral traumas, nephritis, retinitis, atopic dermatitis, psoriasis, myocardial ischemia and acute leukocyte-mediated lung injury such as that which occurs in adult respiratory distress syndrome. The biological activity of the compounds identified above may be assayed in a variety of systems. For example, a compound can be immobilized on a solid surface and adhesion of cells expressing VLA-4 can be measured. Using such formats, large numbers of compounds can be screened. Cells suitable for this assay include any leukocytes known to express VLA-4 such as T cells, B cells, monocytes, eosinophils, and basophils. A number of leukocyte cell lines can also be used, examples include Jurkat and U937. The test compounds can also be tested for the ability to competitively inhibit binding between VLA-4 and VCAM-1, or between VLA-4 and a labeled compound known to bind VLA-4 such as a compound of this invention or antibodies to VLA-4. In these assays, the VCAM-1 can be immobilized on a solid surface. VCAM-1 may also be expressed as a recombinant fusion protein having an Ig tail (e.g., IgG^ so that binding to VLA-4 may be detected in an immunoassay. Alternatively, VCAM-1 expressing cells, such as activated endothelial cells or VCAM-1 transfected fibroblasts can be used. For assays to measure the ability to block adhesion to brain endothelial cells, the assays described in International Patent Application Publication No. WO 91/05038 are particularly preferred. This application is incoφorated herein by reference in its entirety. Many assay formats employ labelled assay components. The labelling systems can be in a variety of forms. The label may be coupled directly or indirectly to the desired component of the assay according to methods well known in the art. A wide variety of labels may be used. The component may be labelled by any one of several methods. The most common method of detection is the use of autoradiography with 3 H, 125 1, 35 S, 14 C, or 32 P labelled compounds and the like. Non-radioactive labels include ligands which bind to labelled antibodies, fluorophores, chemiluminescent agents, enzymes and antibodies which can serve as specific binding pair members for a labelled ligand. The choice of label depends on sensitivity required, ease of conjugation with the compound, stability requirements, and available instrumentation. Appropriate in vivo models for demonstrating efficacy in treating inflammatory responses include EAE (experimental autoimmune encephalomyelitis) in mice, rats, guinea pigs or primates, as well as other inflammatory models dependent upon α4 integrins. Compounds having the desired biological activity may be modified as necessary to provide desired properties such as improved pharmacological properties (e.g. , in vivo stability, bio-availability), or the ability to be detected in diagnostic applications. For instance, inclusion of one or more D-amino acids in the sulfonamides of this invention typically increases in vivo stability. Stability can be assayed in a variety of ways such as by measuring the half-life of the proteins during incubation with peptidases or human plasma or serum. A number of such protein stability assays have been described (see, e.g., Verhoef, et al., Eur. J. Drug Metab. Pharmacokinet., 1990, 15{2}:83-93). For diagnostic puφoses, a wide variety of labels may be linked to the compounds, which may provide, directly or indirectly, a detectable signal. Thus, the compounds of the subject invention may be modified in a variety of ways for a variety of end puφoses while still retaining biological activity. In addition, various reactive sites may be introduced at the terminus for linking to particles, solid substrates, macromolecules, and the like. Labeled compounds can be used in a variety of in vivo or in vitro applications. A wide variety of labels may be employed, such as radionuclides (e.g., gamma-emitting radioisotopes such as technetium-99 or indium- 111), fluorescers (e.g., fluorescein), enzymes, enzyme substrates, enzyme cofactors, enzyme inhibitors, chemiluminescent compounds, bioluminescent compounds, and the like. Those of ordinary skill in the art will know of other suitable labels for binding to the complexes, or will be able to ascertain such using routine experimentation. The binding of these labels is achieved using standard techniques common to those of ordinary skill in the art. In vitro uses include diagnostic applications such as monitoring inflammatory responses by detecting the presence of leukocytes expressing VLA-4. The compounds of this invention can also be used for isolating or labeling such cells. In addition, as mentioned above, the compounds of the invention can be used to assay for potential inhibitors of VLA-4/VCAM-1 interactions. For in vivo diagnostic imaging to identify, e.g. , sites of inflammation, radioisotopes are typically used in accordance with well known techniques. The radioisotopes may be bound to the peptide either directly or indirectly using intermediate functional groups. For instance, chelating agents such as diethylenetriaminepentacetic acid (DTP A) and ethylenediaminetetraacetic acid (EDTA) and similar molecules have been used to bind proteins to metallic ion radioisotopes. The complexes can also be labeled with a paramagnetic isotope for puφoses of in vivo diagnosis, as in magnetic resonance imaging (MRI) or electron spin resonance (ESR), both of which are well known. In general, any conventional method for visualizing diagnostic images can be used. Usually gamma- and positron-emitting radioisotopes are used for camera imaging and paramagnetic isotopes are used for MRI. Thus, the compounds can be used to monitor the course of amelioration of an inflammatory response in an individual. By measuring the increase or decrease in lymphocytes expressing VLA-4 it is possible to determine whether a particular therapeutic regimen aimed at ameliorating the disease is effective. The pharmaceutical compositions of the present invention can be used to block or inhibit cellular adhesion associated with a number of diseases and disorders. For instance, a number of inflammatory disorders are associated with integrins or leukocytes. Treatable disorders include, e.g., transplantation rejection (e.g., allograft rejection), Alzheimer's disease, atherosclerosis, AIDS dementia, diabetes (including acute juvenile onset diabetes), retinitis, cancer metastases, rheumatoid arthritis, acute leukocyte-mediated lung injury (e.g., adult respiratory distress syndrome), asthma, nephritis, and acute and chronic inflammation, including atopic dermatitis, psoriasis, myocardial ischemia, and inflammatory bowel disease (including Crohn' s disease and ulcerative colitis). In preferred embodiments, the pharmaceutical compositions are used to treat inflammatory brain disorders, such as Alzheimer's disease, AIDS dementia, multiple sclerosis (MS), viral meningitis and encephalitis. Inflammatory bowel disease is a collective term for two similar diseases referred to as Crohn' s disease and ulcerative colitis. Crohn' s disease is an idiopathic, chronic ulceroconstrictive inflammatory disease characterized by shaφly delimited and typically transmural involvement of all layers of the bowel wall by a granulomatous inflammatory reaction. Any segment of the gastrointestinal tract, from the mouth to the anus, may be involved, although the disease most commonly affects the terminal ileum and/or colon. Ulcerative colitis is an inflammatory response limited largely to the colonic mucosa and submucosa. Lymphocytes and macrophages are numerous in lesions of inflammatory bowel disease and may contribute to inflammatory injury. Asthma is a disease characterized by increased responsiveness of the tracheobronchial tree to various stimuli potentiating paroxysmal constriction of the bronchial airways. The stimuli cause release of various mediators of inflammation from IgE-coated mast cells including histamine, eosinophilic and neutrophilic chemotactic factors, leukotrines, prostaglandin and platelet activating factor. Release of these factors recruits basophils, eosinophils and neutrophils, which cause inflammatory injury. Atherosclerosis is a disease of arteries (e.g., coronary, carotid, aorta and iliac). The basic lesion, the atheroma, consists of a raised focal plaque within the intima, having a core of lipid and a covering fibrous cap. Atheromas compromise arterial blood flow and weaken affected arteries. Myocardial and cerebral infarcts are a major consequence of this disease. Macrophages and leukocytes are recruited to atheromas and contribute to inflammatory injury. Rheumatoid arthritis is a chronic, relapsing inflammatory disease that primarily causes impairment and destruction of joints. Rheumatoid arthritis usually first affects the small joints of the hands and feet but then may involve the wrists, elbows, ankles and knees. The arthritis results from interaction of synovial cells with leukocytes that infiltrate from the circulation into the synovial lining of the joints. See e.g., Paul, Immunology (3d ed. , Raven Press, 1993). Another indication for the compounds of this invention is in treatment of organ or graft rejection mediated by VLA-4. Over recent years there has been a considerable improvement in the efficiency of surgical techniques for transplanting tissues and organs such as skin, kidney, liver, heart, lung, pancreas and bone marrow. Perhaps the principal outstanding problem is the lack of satisfactory agents for inducing immunotolerance in the recipient to the transplanted allograft or organ. When allogeneic cells or organs are transplanted into a host (i.e. , the donor and donee are different individuals from the same species), the host immune system is likely to mount an immune response to foreign antigens in the transplant (host-versus-graft disease) leading to destruction of the transplanted tissue. CD8 + cells, CD4 cells and monocytes are all involved in the rejection of transplant tissues. Compounds of this invention which bind to alpha-4 integrin are useful, inter alia, to block alloantigen-induced immune responses in the donee thereby preventing such cells from participating in the destruction of the transplanted tissue or organ. See, e.g., Paul et al. , Transplant International 9, 420-425 (1996); Georczynski et al., Immunology 87, 573-580 (1996); Georcyznski et al., Transplant. Immunol. 3, 55-61 (1995); Yang et al., Transplantation 60, 71-76 (1995); Anderson et al. , APMIS 102, 23-27 (1994). A related use for compounds of this invention which bind to VLA-4 is in modulating the immune response involved in "graft versus host" disease (GVHD). See e.g., Schlegel et al. , J. Immunol. 155, 3856-3865 (1995). GVHD is a potentially fatal disease that occurs when immunologically competent cells are transferred to an allogeneic recipient. In this situation, the donor's immunocompetent cells may attack tissues in the recipient. Tissues of the skin, gut epithelia and liver are frequent targets and may be destroyed during the course of GVHD. The disease presents an especially severe problem when immune tissue is being transplanted, such as in bone marrow transplantation; but less severe GVHD has also been reported in other cases as well, including heart and liver transplants. The therapeutic agents of the present invention are used, inter alia, to block activation of the donor T-cells thereby interfering with their ability to lyse target cells in the host. A further use of the compounds of this invention is inhibiting mmor metastasis. Several mmor cells have been reported to express VLA-4 and compounds which bind VLA-4 block adhesion of such cells to endothelial cells. Steinback et al., Urol. Res. 23, 175-83 (1995); Orosz et al., Int. J. Cancer 60, 867-71 (1995); Freedman et al., Leuk. Lymphoma 13, 47-52 (1994); Okahara et al., Cancer Res. 54, 3233-6 (1994). A further use of the compounds of this invention is in treating multiple sclerosis. Multiple sclerosis is a progressive neurological autoimmune disease that affects an estimated 250,000 to 350,000 people in the United States. Multiple sclerosis is thought to be the result of a specific autoimmune reaction in which certain leukocytes attack and initiate the destruction of myelin, the insulating sheath covering nerve fibers. In an animal model for multiple sclerosis, murine monoclonal antibodies directed against VLA-4 have been shown to block the adhesion of leukocytes to the endothelium, and thus prevent inflammation of the central nervous system and subsequent paralysis in the animals. 16 Pharmaceutical compositions of the invention are suitable for use in a variety of drug delivery systems. Suitable formulations for use in the present invention are found in Remington 's Pharmaceutical Sciences, Mace Publishing Company, Philadelphia, PA, 17th ed. (1985). In order to enhance serum half-life, the compounds may be encapsulated, introduced into the lumen of liposomes, prepared as a colloid, or other conventional techniques may be employed which provide an extended serum half-life of the compounds. A variety of methods are available for preparing liposomes, as described in, e.g., Szoka, et al., U.S. Patent Nos. 4,235,871, 4,501,728 and 4,837,028 each of which is incoφorated herein by reference. The amount administered to the patient will vary depending upon what is being administered, the puφose of the administration, such as prophylaxis or therapy, the state of the patient, the manner of administration, and the like. In therapeutic applications, compositions are administered to a patient already suffering from a disease in an amount sufficient to cure or at least partially arrest the symptoms of the disease and its complications. An amount adequate to accomplish this is defined as "therapeutically effective dose. " Amounts effective for this use will depend on the disease condition being treated as well as by the judgment of the attending clinician depending upon factors such as the severity of the inflammation, the age, weight and general condition of the patient, and the like. The compositions administered to a patient are in the form of pharmaceutical compositions described above. These compositions may be sterilized by conventional sterilization techniques, or may be sterile filtered. The resulting aqueous solutions may be packaged for use as is, or lyophilized, the lyophilized preparation being combined with a sterile aqueous carrier prior to administration. The pH of the compound preparations typically will be between 3 and 11 , more preferably from 5 to 9 and most preferably from 7 to 8. It will be understood that use of certain of the foregoing excipients, carriers, or stabilizers will result in the formation of pharmaceutical salts. The therapeutic dosage of the compounds of the present invention will vary according to, for example, the particular use for which the treatment is made, the manner of administration of the compound, the health and condition of the patient, and the judgment of the prescribing physician. For example, for intravenous administration, the dose will typically be in the range of about 20 μg to about 500 μg per kilogram body weight, preferably about 100 μg to about 300 μg per kilogram body weight. Suitable dosage ranges for intranasal administration are generally about 0.1 pg to 1 mg per kilogram body weight. Effective doses can be extrapolated from dose-response curves derived from in vitro or animal model test systems. The following synthetic and biological examples are offered to illustrate this invention and are not to be construed in any way as limiting the scope of this invention. Unless otherwise stated, all temperatures are in degrees Celsius. EXAMPLES In the examples below, the following abbreviations have the following meanings. If an abbreviation is not defined, it has its generally accepted meaning. aq or aq. aqueous AcOH acetic acid bd broad doublet bm broad multiplet bs broad singlet Bn benzyl Boc tert-butoxycarbonyl Boc 2 O di-tert-butyl dicarbonate BOP benzotriazol- 1 -yloxy- tr is (dimethy lamino)phosphonium hexafluorophosphate Cbz carbobenzyloxy CHC1 3 chloroform CH 2 C1 2 dichloromethane (COCl) 2 oxalyl chloride d doublet dd doublet of doublets dt doublet of triplets DBU 1 , 8-diazabicyclo [5.4.0]undec-7-ene DCC 1 ,3-dicyclohexylcarbodiimide DMAP 4-N,N-dimethylaminopyridine DME ethylene glycol dimethyl ether DMF N N-dimethy If ormamide DMSO dimethylsulfoxide EDC — l-(3-dimethylaminopropyl)-3- ethylcarbodiimide hydrochloride Et 3 N = triethylamine EtjO = diethyl ether EtOAc = ethyl acetate EtOH = ethanol eq or eq. = equivalent Fmoc = N-(9-fluorenylmethoxycarbonyl) FmocONSu = N-(9-fluorenylmethoxycarbonyl)- succinimide g = grams h = hour H 2 O = water HBr = hydrobromic acid HCl = hydrochloric acid HOBT = 1-hydroxybenzotriazole hydrate hr = hour K 2 CO 3 = potassium carbonate L = liter m = multiplet MeOH = methanol mg = milligram MgSO 4 = magnesium sulfate mL = milliliter mm = millimeter mM = millimolar mmol = millimol mp = melting point N = normal NaCl = sodium chloride Na 2 CO 3 = sodium carbonate NaHCO 3 = sodium bicarbonate NaOEt = sodium ethoxide NaOH = sodium hydroxide NH 4 C1 = ammonium chloride NMM = N-methylmoφholine Phe = L-phenylalanine Pro = L-proline psi = pounds per square inch PtO 2 = platinum oxide q = quartet quint. = quintet rt = room temperamre s = singlet sat = samrated t = triplet t-BuOH = rt-butanol TFA = trifluoroacetic acid THF = tetrahydrofuran TLC or tic = thin layer chromatography Ts = tosyl TsCl = tosyl chloride TsOH = tosylate μL = microliter In the examples below, all temperatures are in degrees Celsius (unless otherwise indicated). The following Methods were used to prepare the compounds set forth below as indicated. Method 1 N-Tosylation Procedure N-Tosylation of the appropriate amino acid was conducted via the method of Cupps, Boutin and Rapoport J. Org. Chem. 1985, 50, 3972. Method 2 Methyl Ester Preparation Procedure Amino acid methyl esters were prepared using the method of Brenner and Huber Helv. Chim. Acta 1953, 36, 1109. Method 3 BOP Coupling Procedure The desired dipeptide ester was prepared by the reaction of a suitable Ν- protected amino acid (1 equivalent) with the appropriate amino acid ester or amino acid ester hydrochloride (1 equivalent), benzotriazol-1-yloxy- tris(dimethylamino)phosphonium hexafluorophosphate [BOP] (2.0 equivalent), triethylamine (1.1 equivalent), and DMF. The reaction mixture was stirred at room temperamre overnight. The crude product is purified flash chromatography to afford the dipeptide ester. Method 4 Hydrogenation Procedure I Hydrogenation was performed using 10% palladium on carbon (10% by weight) in methanol at 30 psi overnight. The mixmre was filtered through a pad of Celite and the filtrate concentrated to yield the desired amino compound. Method 5 Hydrolysis Procedure I To a chilled (0°C) THF/H 2 O solution (2: 1 , 5 - 10 mL) of the appropriate ester was added LiOH (or NaOH) (0.95 equivalents). The temperamre was maintained at 0°C and the reaction was complete in 1-3 hours. The reaction mixmre was extracted with ethyl acetate and the aqueous phase was lyophilized resulting in the desired carboxylate salt. Method 6 Ester Hydrolysis Procedure II To a chilled (0°C) THF/H 2 O solution (2:1, 5 - 10 mL) of the appropriate ester was added LiOH (1.1 equivalents). The temperature was maintained at 0°C and the reaction was complete in 1-3 hours. The reaction mixmre was concentrated and the residue was taken up into H 2 O and the pH adjusted to 2-3 with aqueous HCl. The product was extracted with ethyl acetate and the combined organic phase was washed with brine, dried over MgSO 4 , filtered and concentrated to yield the desired acid. Method 7 Ester Hydrolysis Procedure III The appropriate ester was dissolved in dioxane/H 2 O (1: 1) and 0.9 equivalents of 0.5 N NaOH was added. The reaction was stirred for 3-16 hours and than concentrated. The resulting residue was dissolved in HjO and extracted with ethyl acetate. The aqueous phase was lyophilized to yield the desired carboxylate sodium salt. Method 8 Sulfonylation Procedure I To the appropriately protected aminopheny lalanine analog (11.2 mmol), dissolved in methylene chloride (25ml) and cooled to -78 °C was added the desired sulfonyl chloride (12 mmol) followed by dropwise addition of pyridine (2 mL). The solution was allowed to warm to room temperamre and was stirred for 48 hr. The reaction solution was transferred to a 250 mL separatory funnel with methylene chloride (100 mL) and extracted with IN HCl (50 mL x 3), brine (50 mL), and water (100 mL). The organic phase was dried (MgSO4) and the solvent concentrated to yield the desired product. Method 9 Reductive Amination Procedure Reductive amination of Tos-Pro-p-NH2-Phe with the appropriate aldehyde was conducted using acetic acid, sodium triacetoxyborohydride, methylene chloride and the combined mixmre was stirred at room temperamre overnight. The crude product was purified by flash chromatography. Method 10 BOC Removal Procedure Anhydrous hydrochloride (HCl) gas was bubbled through a methanolic solution of the appropriate Boc-amino acid ester at 0°C for 15 minutes and the reaction mixmre was stirred for three hours. The solution was concentrated to a syrup and dissolved in Et 2 O and reconcentrated. This procedure was repeated and the resulting solid was placed under high vacuum overnight. Method 11 tert-Butyl Ester Hydrolysis Procedure I The tert-butyl ester was dissolved in CH 2 C1 2 and treated with TFA. The reaction was complete in 1-3 hr at which time the reaction mixmre was concentrated and the residue dissolved in H 2 O and lyophilized to yield the desired acid. Method 12 EDC Coupling Procedure I To a CH 2 C1 2 solution (5-20 mL) of N-(toluene-4-sulfonyl)-L-proline (1 equivalent), the appropriate amino acid ester hydrochloride (1 equivalent), N-methylmoφholine (1.1-2.2 equivalents) and 1-hydroxybenzotriazole (2 equivalents) were mixed, placed in an ice bath and l-(3- dimethylaminopropyl)-3 -ethyl carbodumide (1.1 equivalents) added. The reaction was allowed to rise to room temperamre and stirred overnight. The reaction mixmre was poured into H 2 O and the organic phase was washed with sat. NaHCO 3 , brine, dried (MgSO 4 or Na 2 SO 4 ), filtered and concentrated. The crude product was purified by column chromatography. Method 13 EDC Coupling Procedure II To a DMF solution (5-20 mL) of the appropriate N-protected amino acid (1 equivalent), the appropriated amino acid ester hydrochloride (1 equivalent), Et 3 N (1.1 equivalents) and 1 -hydroxy benzotriazole (2 equivalents) were mixed, placed in an ice bath and l-(3- dimethylaminopropyl)-3-ethyl carbodumide (1.1 equivalents) added. The reaction was allowed to rise to room temperamre and stirred overnight. The reaction mixmre was partitioned between EtOAc and H 2 O and the organic phase washed with 0.2 N citric acid, H 2 O, sat. NaHCO 3 , brine, dried (MgSO 4 or Na 2 SO 4 ), filtered and concentrated. The crude product was purified by column chromatography or preparative TLC. Method 14 Sulfonylation Procedure II The appropriate sulfonyl chloride was dissolved in CH 2 C1 2 and placed in an ice bath. L-Pro-L-Phe-OMe • HCl (1 equivalent) and Et 3 N (1.1 equivalent) was added and the reaction allowed to warm to room temperamre and stirred overnight under an atmosphere of nitrogen. The reaction mixmre was concentrated and the residue partitioned between EtOAc and H 2 O and the organic phase washed with sat. NaHCO 3 , brine, dried (MgSO 4 or Na 2 SO 4 ), filtered and concentrated. The crude product was purified by column chromatography or preparative TLC. Method 15 Sulfonylation Procedure III To a solution of L-Pro-L-4-(3-dimethylaminopropyloxy)-Phe-OMe [prepared using the procedure described in Method 10] (1 equivalent) in CH 2 C1 2 was added Et 3 N (5 equivalents) followed by the appropriate sulfonyl chloride (1.1 equivalent). The reaction was allowed to warm to room temperamre and stirred overnite under an atmosphere of nitrogen. The mixmre was concentrated, dissolved in EtOAc, washed with sat. NaHCO 3 and 0.2 N citric acid. The aqueous phase was made basic with solid NaHCO 3 and the product extracted with EtOAc. The organic phase was washed with brine, dried (MgSO 4 or Na 2 SO 4 ), filtered and concentrated. The crude methyl ester was purified by preparative TLC. The corresponding acid was prepared using the procedure described in Method 7. Method 16 Hydrogenation Procedure II To a methanol (10 -15 mL) solution of the azlactone was added NaOAc (1 equivalent) and 10% Pd/C. This mixmre was placed on the hydrogenator at 40 psi H 2 . After 8 - 16 hours, the reaction mixmre was filtered through a pad of Celite and the filtrate concentrated to yield the dehydrodipeptide methyl ester. The ester was dissolved in dioxane/H 2 O (5-10 mL), to which was added 0.5 N NaOH (1.05 equivalents). After stirring for 1- 3 hours, the reaction mix was concentrated and the residue was redissolved in H 2 O and washed with EtOAc. The aqueous phase was made acidic with 0.2 N HCl and the product was extracted with EtOAc. The combined organic phase was washed with brine (1 x 5 mL), dried (MgSO 4 or Na 2 SO 4 ), filtered and concentrated to yield the acid as approximately a 1 : 1 mixmre of diastereomers. Method 17 tert-Butyl Ester Hydrolysis Procedure II The tert-butyl ester was dissolved in CH 2 C1 2 (5 mL) and treated with TFA (5 mL). The reaction was complete in 1-3 hours at which time the reaction mixture was concentrated and the residue dissolved in H 2 O and concentrated. The residue was redissolved in H 2 O and lyophilized to yield the desired product. Example 1 Synthesis of V-(Toluene-4-sulfonyl)-L-prolyl-L-4-(4-methylpiperazin- l-ylcarbonyloxy)phenylalanine Ethyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 4 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CD 3 ) 2 SO): δ = 8.33 (d, IH), 7.70 (d, 2H), 7.41 (d, 2H), 7.24 (d, 2H), 7.00 (d, 2H), 4.52-4.44 (m, IH), 4.09-4.00 (m, 3H), 3.53 (bs, 2H), 3.38-3.31 (m, 3H), 3.11-3.01 (m, 3H), 2.39 (s, 3H), 2.32 (bs, 4H), 2.19 (s, 3H), 1.61-1.50 (m, 3H), 1.43-1.38 (m, IH), 1.13 (t, 3H). 13 C NMR (CD 3 ) 2 SO): δ = 171.1, 171.1, 153.9, 149.8, 143.6, 134.1, 133.9, 130.0, 129.8, 127.4, 121.5, 61.2, 60.7, 54.2, 54.1 , 53.3, 49.0, 45.7, 44.0, 43.4, 35.8, 30.5, 23.8, 21.0, 14.0. Example 2 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine Ethyl Ester Into a reaction vial were combined 7.00 g (15.2 mmol, 1.0 eq) Ts- Pro-Tyr(H)-OEt and 1.86 g (15.2 mmol, 1.0 eq) DMAP. Methylene chloride (50 mL), triethylamine (2.12 mL - 1.54 g, 15.2 mmol, 1.0 eq), and dimethylcarbamyl chloride (1.68 mL — 1.96 g, 18.2 mmol, 1.2 eq) were then added. The vial was capped tightly, and the reaction solution swirled to obtain a homogeneous solution. The reaction solution was then heated to 40°C. After 48 h, TLC of the resulting colorless solution indicated complete conversion. The workup of the reaction solution was as follows: add 50 mL EtOAc and 50 mL hexanes to the reaction mixmre, and wash with 3 x 50 mL 0.5 mL hexanes to the reaction mixmre, and wash with 3 x 50 mL 0.5 M citric acid, 2 x 50 mL water, 2 x 50 mL 10% K,CO 3 , and 1 x 50 mL sat. NaCl. Dry with MgSO 4 . Filter. Evaporate to obtain 8.00 g (99%) of the title compound as a clear oil, which solidifies upon standing. Recrystallize from 5:3:2 heptane/EtOAc/CH 2 Cl 2 . NMR data was as follows: Η NMR (CD 3 ) 2 SO): δ = 8.32 (d, IH), 7.70 (d, 2H), 7.41 (d, 2H), 7.23 (d, 2H), 7.00 (d, 2H), 4.52-4.44 (m, IH), 4.09-4.02 (m, 3H), 3.37- 3.31 (m, IH), 3.11-2.96 (m, 3H), 3.00 (s, 3H), 2.87 (s, 3H), 2.39 (s, 3H), 1.61-1.50 (m, 3H), 1.43-1.38 (m, IH), 1.13 (t, 3H). 13 C NMR (CD 3 ) 2 SO): δ = 171.1, 171.1, 154.0, 150.0, 143.6, 133.9, 133.9, 130.0, 129.8, 127.4, 121.5, 61.2, 60.6, 53.3, 49.0, 36.3, 36.1, 35.8, 30.5, 23.8, 21.0, 14.0. Example 3 Synthesis of N-(Toluene-4-sulfonyl)-L-proIyl-L-4-(4-methylpiperazin- l-ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 4 and substitution of appropriate starting materials. NMR data was as follows: ! H NMR (CDC1 3 ): δ = 7.72 (d, 2H), 7.36 (d, IH), 7.33 (d, 2H), 7.16 (d, 2H), 7.03 (d, 2H), 5.07 (Sept., IH), 4.78 (dt, IH), 4.08-4.05 (m, IH), 3.67 (bs, 2H), 3.57 (bs, 2H), 3.41-3.35 (m, IH), 3.24 (dd, IH), 3.15-3.07 (m, IH), 3.04 (dd, IH), 3.46-2.43 (m, 7H), 2.34 (s, 3H), 2.05-2.02 (m, IH). 13 C NMR (CDC1 3 ): δ = 170.9, 170.4, 153.6, 150.5, 144.3, 133.2, 133.1, 130.2, 130.0, 127.9, 121.7, 69.5, 62.2, 54.7, 53.4, 49.6, 46.1, 44.3, 43.7, 37.2, 29.7, 24.1, 21.6, 21.6, 21.4. Example 4 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(4-methylpiperazin- l-ylcarbonyloxy)phenylalanine tert-Butyl Ester Combine 41.2 g (84.34 mmol, 1.0 eq) Ts-Pro-Tyr(H)-OtBu and 17.0 g (84.34 mmol, 1.0 eq) 4-nitrophenyl chloroformate. Add 700 mL CH 2 C1 2 . Cap with a septum. Attach a N 2 line. Immerse the flask in a 4: 1 water/EtOH + dry ice slurry, and stir to cool to -15°C. Add 29.38 mL (21.33 g, 210.81 mmol, 2.5 eq) Et 3 N over five minutes with stirring. Stir at -10 to -15 °C for 1 h. Add 9.35 mL (8.45 g, 84.34 mmol, 1.0 eq) N-methyl piperazine over 3 minutes with stirring. Stir overnight while warming to room temperamre. Dilute with 700 mL hexanes. Wash repeatedly with 10% K 2 CO 3 , until no yellow color (4-nitrophenol) is seen in the aqueous layer. Wash with sat. NaCl. Dry over anhydrous MgSO 4 . Filter. Evaporate. Dissolve in 500 mL EtOH, and evaporate, to remove E^N. Repeat once. Dissolve in 400 mL EtOH, and add 600 mL water with stirring, to precipitate a solid or oil. If an oil, stir vigorously to solidify. Isolate the solid by filtration. Repeat dissolution, precipitation, and filtration, once. Rinse with water to remove traces of yellow color. High vacuum to constant mass yields the title compound as a white solid. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.72 ( d, 2H), 7.33 (d, 3H), 7.17 (d, 2H), 7.02 (d, 2H), 4.71 (q, IH), 4.09-4.06 (m, IH), 3.67 (bs, 2H), 3.57 (bs, 2H), 3.41-3.34 (m, IH), 3.22 (dd, IH), 3.16-3.09 (m, IH), 3.03 (dd, IH), 2.46- 2.43 (m, 7H), 2.34 (s, 3H), 2.05-2.02 (m, IH), 1.57-1.43 (m, 3H), 1.47 (s, 9H). 13 C NMR (CDC1 3 ): δ = 171.8, 169.9, 153.6, 150.4, 144.3, 133.4, 133.1, 130.3, 130.0, 127.9, 121.6, 82.6, 62.3, 54.5, 53.8, 49.6, 46.1, 44.3, 43.7, 37.3, 29.7, 27.8, 24.1, 21.4. Example 5 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(4-methylpiperazin- l-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 1 using the procedure described in Method 7. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.74 (d, 2H), 7.42 (d, 2H), 7.26 (d, 2H), 7.04 (d, 2H), 4.58-4.54 (m, IH), 4.16-4.12 (m, IH), 3.70 (bs, 2H) 3.53 (bs, 2H), 3.43-3.31 (m, IH), 3.26-3.13 (m, 7H), 2.82 (s, 3H), 2.43 (s, 3H), 1.98-1.94 (m, IH), 1.76-1.51 (m, 3H). 13 C NMR (CD 3 OD): δ = 175.7, 173.6, 154.8, 151.6, 146.1, 136.3, 134.8, 131.9, 131.3, 129.1, 122.7, 63.6, 55.9, 53.9, 50.7, 43.5, 37.6, 31.3, 25.5, 21.5. Example 6 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine n-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CD 3 ) 2 SO: δ = 8.31 (d, IH), 7.70 (d, 2H), 7.41 (d, 2H), 7.23 (d, 2H), 6.99 (d, 2H), 4.53-4.46 (m, IH), 4.10-4.01 (m, IH), 3.63-3.30 (m, IH), 3.10-2.96 (m, 3H), 3.00 (s, 3H), 2.88 (s, 3H), 2.39 (s, 3H), 1.59-1.30 (m, 6H), 1.33-1.20 (m, 2H), 0.85 (t, 3H). 13 C NMR (CD 3 ) 2 SO: δ = 171.4, 171.3, 154.2, 150.2, 143.7, 134.0, 130.1, 130.0, 127.6, 121.7, 64.3, 61.2, 59.2, 53.4, 49.0, 36.2, 36.0, 35.8, 30.0, 23.8, 21.0, 18.5, 13.5. Example 7 Synthesis of N-(Toluene-4-suIfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine Cyclopentyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. ΝMR data was as follows: Η ΝMR (CD 3 ) 2 SO: δ = 8.27 (d, IH), 7.70 (d, 2H), 7.41 (d, 2H), 7.22 (d, 2H), 6.99 (d, 2H), 5.04 (bs, IH), 4.48-4.40 (m, IH), 4.08-4.05 (m, IH), 3.34-3.30 (m, IH), 3.09-2.95 (m, 3H), 3.00 (s, 3H), 2.88 (s, 3H), 2.39 (s, 3H), 1.76-1.74 (m, 2H), 1.57-1.40 (m, 10H). 13 C ΝMR (CD 3 ) 2 SO: δ = 171.3, 171.0, 154.2, 150.2, 432.7, 134.1, 130.1, 130.0, 127.6, 121.6, 77.4, 61.2, 53.4, 49.0, 36.2, 36.1, 35.7, 32.0, 30.5, 23.8, 23.2, 21.0. Example 8 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. ΝMR data was as follows: Η ΝMR (CD 3 ) 2 SO: δ = 8.18 (d, IH), 7.71 (d, 2H), 7.41 (d, 2H), 7.23 (d, 2H), 6.99 (d, 2H), 4.42-4.38 (m, IH), 4.10-4.07 (m, IH), 3.37-3.30 (m, IH), 3.09-2.95 (m, 3H), 3.00 (s, 3H), 2.88 (s, 3H), 2.39 (s, 3H), 1.58-1.50 (m, 3H), 1.40-1.30 (m, IH), 1.36 (s, 9H). 13 C ΝMR (CD 3 ) 2 SO: δ = 171.1, 170.3, 154.2, 150.2, 143.8, 134.2, 134.1 , 130.2, 130.0, 127.6, 121.6, 81.0, 61.3, 53.8, 49.0, 36.3, 36.0, 35.9, 30.5, 27.5, 23.8, 21.0. Example 9 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI-L-4- (N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 2 using the procedure described in Method 7. ΝMR data was as follows: Η ΝMR (CD 3 ) 2 SO: δ = 8.13 (d, IH), 7.70 (d, 2H), 7.41 (d, 2H), 7.23 (d, 2H), 6.99 (d, 2H), 4.51-4.44 (m, IH), 4.11-4.09 (m, IH), 3.40-3.34 (m, 2H), 3.11-2.94 (m, 3H), 3.00 (s, 3H), 2.87 (s, 3H), 2.39 (s, 3H), 1.59-1.36 (m, 4H). 13 C ΝMR (CD 3 ) 2 SO: δ = 172.7, 171.2, 153.6, 150.2, 143.8, 134.3, 134.0, 130.2, 130.0, 127.6, 121.6, 61.3, 53.2, 49.0, 36.3, 36.1, 35.9, 30.4, 23.8, 21.0. Example 10 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-3- (N,N-dimethylcarbamyloxy)phenylalanine Ethyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.74 (m, 2H), 7.70-7.36 (m, 4H), 7.24-7.14 (m, 3H), 6.93-4.90 (m, IH), 4.78-4.27 (m, 3H), 4.05-3.55 (m, .5H), 3.48-3.43 (m, .5H), 3.37-3.30 (m, 3H), 3.02-3.08 (bs, 3H), 2.99 (bs, 3H), 2.45 (s, 1.5H), 2.43 (s, 1.5H), 2.12 (m, IH), 198, 1.80 (m, .5M), 1.62-1.44 (m, 2.5H), 1.29 (t, 1.5H), 1.24 (t, 1.5H). 13 C NMR (CDC1 3 ): δ = 171.1, 171.0, 170.9, 154.9, 154.8, 151.8, 151.6, 144.4, 144.3, 137.6, 137.1 , 133.1, 132.9, 130.0, 129.9, 129.5, 129.2, 127.9, 127.9, 126.5, 126.1, 122.9, 122.7, 120.7, 120.5. Example 11 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.76 (d, 2H), 7.35 (d, 2H), 7.22 (d, 2H), 7.01 (m, 3H), 5.05 (m, IH), 4.85 (m, IH), 4.57 (d, IH), 4.38 (d, IH), 3.86 (s,lH), 3.19-3.00 (m, 2H), 3.09 (s, 3H), 3.01 (s, 3H), 2.45 (s, 3H), 1.24 (t, 6H), 1.16 (s, 3H), 1.09 (s, 3H). 13 C NMR (CDC1 3 ): δ = 170.3, 168.4, 154.9, 150.6, 144.8, 132.9, 132.8, 130.3, 130.0, 128.2, 121.7, 73.4, 69.5, 54.5, 53.2, 50.4, 37.7, 36.5, 36.3, 29.0, 23.8, 21.5, 21.4. Example 12 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.75 (d, 2H), 7.34 (d, 2H), 7.23 (d, 2H), 7.05- 6.98 (m, 3H), 4.76 (m, IH), 4.56 (d, IH), 4.40 (d, IH), 3.85 (s, IH), 3.09- 3.00 (m, 8H), 2.44 (s, 3H), 1.43 (s, 3H), 1.16 (s, 3H), 1.09 (s, 3H). 13 C NMR (CDC1 3 ): δ = 169.8, 168.3, 154.9, 150.6, 144.8, 133.2, 132.9, 130.4, 130.0, 128.2, 121.6, 82.6, 73.4, 54.6, 53.8, 50.4, 37.8, 36.5, 36.3, 29.0, 27.7, 23.8, 21.5. Example 13 Synthesis of N-(Toluene-4-sulfonyI)-L-(5,5-dimethyl)thiaprolyI- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 11 using the procedure described in Method 7. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.76 (d, 2H), 7.35 (d, 2H), 7.25 (d, 2H), 7.14 (d, IH), 7.02 (d, 2H), 5.17 (br s, IH), 4.89 (m, IH), 4.56 (d, IH), 4.40 (d, IH), 3.90 (s, IH), 3.30-3.00 (m, 8H), 2.43 (s, 3H), 1.09 (s, 6H). 13 C NMR (CDC1 3 ): δ = 172.7, 169.3, 155.2, 150.6, 144.9, 133.1, 132.7, 130.5, 130.1, 128.1, 121.9, 73.3, 54.5, 53.3, 50.5, 36.9, 36.6, 36.4, 29.0, 23.7, 21.5. Example 14 Synthesis of N-(Toluene-4-suIfonyl)-L-[(l , l-dioxo)thiamorpholin- 3-carbonyl]-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester L-Thiamoφholine-5-carboxylic acid was prepared by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). N-(Toluene- 4-sulfonyl)-L-thiamoφholine-5-carboxylic acid was prepared using the procedure described in Method 1 and was then coupled to t-butyl tyrosine in DMF in the presence of BOP and ΝMM, to give after aqueous workup and flash chromatography N-(Toluene-4-sulfonyl)-L-[thiamoφholin-3-carbonyl]- L-4-phenylalanine tert-butyl ester. Formation of the 4-(N,N-dimethylcarbamyloxy) group was per Example 2 above and oxidation of the thiamoφholino group to the 1,1-dioxo- thiamoφholino group was per Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522). ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.68 (d, 2H), 7.37 (d, 2H), 7.08 (m, 4H), 6.73 (d, IH), 5.11 (m, IH), 4.62 (m, IH), 4.23 (m, IH), 4.00 (m, IH), 3.82 (m, IH), 3.14 (s, 3H), 3.03 (s, 3H), 2.80 (m, 5H), 2.44 (s, 3H), 1.48 (s, 9H). 13 C ΝMR (CDC1 3 ): δ = 171.3, 169.9, 164.4, 145.6, 135.4, 132.6, 130.8, 130.4, 127.3, 121.9, 83.0, 56.1, 53.8, 49.4, 48.7, 44.5, 42.0, 36.9, 36.6, 36.4, 27.8, 21.5. Example 15 Synthesis of N-(Toluene-4-sulfonyI)-L-[(l , l-dioxo)thiamorpholin- 3-carbonyl]-L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 14 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.77 (d, 2H), 7.40 (d, 2H), 7.22 (d, 2H), 7.00 (d, 2H), 5.19 (m, IH), 4.65 (m, IH), 4.30 (m, IH), 3.95 (m, IH), 3.61 (m, IH), 3.20 (m, 5H), 3.09 (s, 3H), 2.97 (s, 3H), 2.43 (s, 3H). 13 C NMR (CD 3 OD): δ = 174.1 , 168.0, 157.0,152.0, 146.4, 137.7, 135.3, 131.7, 131.6, 128.8, 123.0, 57.1, 54.8, 51.1, 50.9, 48.0, 47.7, 43.2, 37.4, 36.8, 36.7, 21.5. Example 16 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-4-(4-methylpiperazin-l-ylcarbonyloxy)phenylalanine tørt-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 4 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.74 (d, 2H), 7.33 (d, 2H), 7.25 (d, 2H), 7.20- 7.00 (m, 3H), 4.74 (m, IH), 4.55 (d, IH), 4.38 (d, IH), 3.83 (s, IH), 3.66 (br m, 2H), 3.57 (br m, 2H), 3.08-3.05 (m, 2H), 2.45-2.42 (m, 7H), 2.33 (s, 3H), 1.42 (s, 9H), 1.15 (s, 3H), 1.08 (s, 3H). 13 C NMR (CDC1 3 ): δ = 169.7, 168.2, 153.6, 150.3, 144.7, 133.3, 132.7, 130.4, 129.9, 128.1, 121.5, 82.6, 73.4, 54.5, 53.7, 50.4, 46.0, 44.2, 43.6, 37.7, 28.9, 27.7, 23.8, 21.4. Example 17 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-4-(4-methylpiperazin-l-ylcarbonyloxy)phenylalanine The title compound was prepared from the product Example 16 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 8.31 (d, IH), 7.72 (d, 2H), 7.42-7.35 (m, 4H), 7.08 (d, 2H), 4.90-4.68 (m, IH), 4.64-4.61 (m, IH), 4.47-4.44 (m, IH), 4.01 (s, IH), 3.36-3.32 (br m, 4H), 3.27-3.25 (m, IH), 3.22-3.10 (m, IH), 2.94 (s, 3H), 2.43 (s, 3H), 1.14 (s, 3H), 1.07 (s, 3H). Example 18 Synthesis of N-(Toluene-4-sulfonyl)sarcosyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.66 (d, 2H), 7.34 (d, 2H), 7.18 (d, 2H), 7.07 (d, 2H), 6.98 (d, IH), 5.03 (m, IH), 4.81 (m, IH), 3.69 (d, IH), 3.49 (d, IH), 3.08 (m, 2H), 3.04 (s, 3H), 2.99 (s, 3H), 2.63 (s, 3H), 2.43 (s, 3H). 13 C NMR (CDC1 3 ): δ = 167.4, 154.9, 150.8, 144.4, 132.6, 130.2, 130.1, 127.7, 122.0, 110.9, 69.5, 57.3, 53.9, 53.0, 37.1 , 36.6, 21.6, 21.4. Example 19 Synthesis of N-(ToIuene-4-sulfonyl)sarcosyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.67 (d, 2H), 7.34 (d, 2H), 7.19 (d, 2H), 7.03 (d, 2H), 6.98 (d, IH), 4.76 (m, IH), 3.67 (q, IH), 3.06 (m, 2H), 3.16 (s, 3H), 2.99 (s, 3H), 2.64 (s, 3H), 2.43 (s, 3H), 1.42 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.0, 137.2, 154.9, 150.7, 144.3, 133.2, 132.9, 130.3, 130.0, 127.7, 121.9, 82.6, 83.9, 53.3, 37.2, 36.6, 36.4, 27.9, 21.4. Example 20 Synthesis of N-(Toluene-4-sulfonyl)sarcosyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 18 using the procedure described in Method 7. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.41 (d, 2H), 7.10 (d, 2H), 6.98 (d, 2H), 6.75 (d, 2H), 4.42 (m, IH), 3.43 (m, 2H), 3.04 (m, 2H), 2.80 (s, 3H), 2.69 (s, 3H), 2.33 (s, 3H), 2.14 (s, 3H). 13 C NMR (CDC1 3 ): δ = 174.2, 170.2, 156.9, 151.9, 145.6, 135.5, 135.2, 131.4, 131.1, 128.9, 123.0, 54.6, 54.0, 37.4, 36.8, 36.7, 21.4. Example 21 Synthesis of N-(Toluene-4-sulfonyl)-L-proIyl-L-4- (N,N-dimethylaminosulfonyloxy)phenylalanine tert-Butyl Ester Substimting dimethysulfamoyl chloride for dimethylcarbamyl chloride, and following the method for the preparation of Example 2, gave the title compound. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.72 (d, 2H), 7.34 (d, 2H), 7.21 (s, 4H), 4.69 (m, IH), 4.04 (m, IH), 3.4 (m, IH), 3.24 (m, 3H), 2.96 (s, 6H), 2.42 (s, 3H), 2.02 (m, IH), 1.45 (m, 13H). 13 C NMR (CDCI 3 ): δ = 166.3, 165.3, 144.8, 140.0, 130.9, 126.4, 125.6, 123.5, 117.3, 95.5, 78.3, 57.8, 49.2, 45.2, 34.2, 32.9, 25.0, 23.4, 19.7, 17.1. Example 22 Synthesis of N-(Toluene-4-sulfonyl)-L-proIyl-L-4- (N,N-dimethylaminosulfonyloxy)phenylalanine The title compound was prepared from the product of Example 21 using the procedure described in method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.73 (d, 2H), 7.41 (d, 2H), 7.38 (d, 2H), 7.22 (d, 2H), 4.69 (m, IH), 4.11 (m, IH), 3.41 (m, 2H), 3.19 (m, 2H), 2.94 (s, 6H), 2.41 (s, 3A), 1.78 (m, IH), 1.61 (m, 3H). 13 C NMR (CD 3 OD): δ = 174.3, 174.0, 150.8, 145.9, 137.3, 135.1, 132.1 , 131.2, 129.1, 123.1, 63.3, 54.6, 50.6, 39.1, 37.5, 31.6, 25.3, 21.5. Example 23 Synthesis of N-(Toluene-4-sulfonyl)-sarcosyl-L-(4- morpholinecarbamyloxy) phenylalanine t-butyl ester Substimting sacrosine for L-proline in the preparation of Ts-Pro-Tyr(H)- O-t-butyl ester and substimtion of 4-moφholinecarbonyl chloride for dimethylcarbamyl chloride, and following the method for the preparation of Example 2, gave the title compound as a white solid. NMR data was as follows: Η NMR (CDCI 3 ): δ 7.61 (d, 2H), 7.28 (d, 2H), 7.16 (d, 2H), 7.02 (d, 2H), 4.69 (m, IH), 3.67 (m, 8H), 3.58 (m, IH), 3.48 (m, IH), 3.06 (m, 2H), 2.59 (s, 3H), 2.36 (s, 3H), 1.26 (s, 9H). 13 C NMR (CDCI 3 ): δ 169.7, 167.1, 153.5, 150.1, 144.1, 133.1, 133.0, 133.0, 130.1, 129.8, 127.4, 121.6, 82.6, 66.3, 53.6, 53.1, 44.5, 43.7, 36.9, 36.4, 27.6, 21.2. Example 24 Synthesis of N-(Toluene-4-sulfonyl)sarcosyl-L-4- (isonipecotoyloxy)phenylalanine The title compound was prepared from the product of Example 23 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.30 (d, 2H), 7.02 (d, 2H), 6.88 (d, 2H), 6.67 (d, 2H), 4.33 (m, IH), 3.32 (m, 3H), 3.25 (m, 2H), 3.12 (m, 3H), 2.89 (m, IH), 2.70 (m, 3H), 2.22 (s, 3H), 2.03 (s, 3H). 13 C NMR (CD 3 OD): δ = 174.2, 170.3, 155.6, 151.7, 145.6, 135.8, 135.2, 131.5, 131.1, 128.9, 123.0, 67.5, 54.6, 54.0, 37.4, 36.8, 21.5. Example 25 Synthesis of iV-(Toluene-4-sulfonyl)-L-[(l , l-dioxo)thiamorpholin- 3-carbonyl]-L-4-(morpholin-4-ylcarbonyloxy)phenylalanine terf-Butyl Ester Substimtion of 4-moφholinecarbonyl chloride for dimethylcarbamyl chloride, and following the methods for the preparation of Example 2 and 14, gave the title compound as a white solid. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.76 (d, IH), 7.68 (d, IH), 7.37 (m, 2H), 7.14 (m, 2H), 7.05 (m, IH), 6.97 (d, IH), 6.80 (d, 0.5H), 6.57 (d, 0.5H), 5.09 (m, 0.5H), 4.91 (m, 0.5H), 4.75 (m, 0.5H), 4.62 (m, 0.5H), 4.25 (m, 0.5H), 4.09 (m, 2H), 3.79 (m, 4H), 3.65 (m, 4H), 2.91 (s, 3H), 2.44 (s, 3H), 1.69 (s, 4H), 1.44 (s, 5H). 13 C NMR (CDCI 3 ): δ = 170.0, 169.8, 164.8, 164.4, 153.7, 150.4, 145.6, 145.4, 135.4, 135.3, 132.9, 130.8, 130.7, 130.5, 130.4, 127.5, 127.2, 122.1, 121.8, 83.01, 82.8, 66.4, 56.1, 56.1, 53.7, 53.6, 49.5, 49.3, 48.6, 44.7, 43.9, 42.0, 41.6, 36.9, 36.3, 27.8, 21.5. Example 26 Synthesis of N-(Toluene-4-sulfonyl)-L-[(l , l-dioxo)thiamorpholin- 3-carbonyl]-L-4-(morphoIin-4-yIcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 25 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.67 (m, 2H), 7.32 (m, 2H), 7.08 (m, 2H), 6.93 (m, 2H), 5.09 (m, IH), 4.54 (m, IH), 4.19 (m, 0.5H), 4.02 (m, 0.5H), 3.81 (m, 0.5H), 3.66 (m, 8H), 2.99 (m, 7H), 2.32 (s, 3H). 13 C NMR (CD 3 OD): δ = 174.0, 168.0, 155.7, 151.9, 151.8, 146.6, 146.4, 137.5, 135.5, 135.3, 131.7, 131.6, 131.6, 128.8, 123.3, 122.9, 67.6, 57.3, 57.1, 54.8, 51.1, 50.9, 50.6, 46.0, 45.3, 45.2, 43.0, 37.4, 37.0, 21.5. Example 27 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-prolyl-L-4- (N,/V-dimethylcarbamyloxy)phenylalanine tert-Buty\ Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: 13 C NMR (CDC1 3 ): δ = 7.87-7.83 (m, 2H), 7.26-7.13 (m, 5H), 4.74- 4.69 (m, IH), 4.05 (m, IH), 3.36 (m, IH), 3.24-3.17 (m, IH), 3.11-3.01 (m, 4H), 2.97 (s, 3H), 2.05-2.02 (m, IH), 1.60-1.47 (m, 3H), 1.46 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.6, 170.0, 165.7, 154.9, 150.6, 133.2, 132.4, 130.7, 130.2, 121.7, 116.7, 82.7, 62.3, 53.7, 49.6, 37.2, 36.6, 36.4, 29.9, 27.9, 24.2. Example 28 Synthesis of N-(Toluene-4-sulfonyl)sarcosyl-L-4- (4-methylpiperazin-l-ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 8.17 (d, IH), 7.59 (d, 2H), 7.26 (d, 2H), 7.13 (d, 2H), 7.00 (d, 2H), 4.66 (m, IH), 3.60 (m, 6H), 3.04 (m, 2H), 2.56 (s, 3H), 2.40 (m, 7H), 2.34 (s, 3H), 1.41 (s, 9H). 13 C NMR (CDC1 3 ): δ = 169.7, 167.0, 153.4, 150.2, 144.0, 133.0, 132.9, 130.1, 129.8, 127.4, 121.6, 82.2, 54.3, 53.5, 53.1, 45.8, 44.2, 43.5, 36.9, 27.6, 21.2. Example 29 Synthesis of N-(Toluene-4-sulfonyl)-L-(l,l-dioxo-5,5-dimethyl)- thiaprolyI-L-4-(N,N-dimethylcarbamyloxy)phenyIalanine tert-Butyl Ester The product of Example 12 was oxidized by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525), yielding the title compound as a white solid. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.73 (d, 2H), 7.36 (d, 2H), 7.21 (d, 2H), 7.06- 6.95 (m, 3H), 4.79 (m, IH), 4.38 (dd, 2H), 4.10 (s, IH), 3.18-2.95 (m, 8H), 2.43 (s, 3H), 1.45 (s, 9H), 1.33 (s, 3H), 1.08 (s, 3H). 13 C NMR (CDCI 3 ): δ = 169.8, 166.2, 154.9, 120.7, 145.8, 133.0, 131.9, 130.2, 128.5, 121.9, 82.9, 68.0, 60.9, 59.3, 53.9, 37.5, 36.6, 36.3, 27.7, 21.6, 19.3, 18.5. Example 30 Synthesis of N-(l-Methylimidazolyl-4-sulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 106 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 8.07 (d, IH), 7.75 (s, IH), 7.71 (s, IH), 7.25 (d, 2H), 7.01 (d, 2H), 4.71-4.66 (m, IH), 4.28-4.24 (m, IH), 3.77 (s, 3H), 3.42-3.05 (m, 3H), 3.09 (s, 3H), 2.96 (s, 3H), 1.84-1.69 (m, 2H), 1.61- 1.54 (m, 2H). 13 C NMR (CDC1 3 ): δ = 174.4, 174.1, 156.9, 151.9, 141.8, 137.7, 135.6, 131.6, 127.6, 122.9, 63.7, 54.7, 50.8, 37.4, 36.8, 36.7, 34.3, 31.6, 25.4. Preparative Example A Synthesis of 2-(Saccharin-2-yl)propionoyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tørt-Butyl Ester N-(Benzisothiazolone)-L-alanyl-L-tyrosine t-butyl ester was prepared by first combining sodium hydride (washed free of mineral oil) in THF chilled to 0°C, and a solution of N-(2-methoxycarbonyl)sulfonyl-L-alanine-L- tyrosine t-butyl ester in THF which was added dropwise. The reaction was stirred at 0°C for one hour and then at room temperamre for two hours. The reaction mixmre was extracted with EtOAc and 0.2 Ν HCl, the combined EtOAc layers were washed successively with 0.2 Ν HCl, satd. ΝaHCO,, and satd. ΝaCl. The organic layer was dried over MgSO 4 , filtered and concentrated. The residue was filtered by silica gel chromatography to afford N-(benzisothiazolone)-L-alanyl-L-tyrosine t-butyl ester. The title compound was then prepared following the procedure described in Example 2. ΝMR data was as follows: Η NMR (DMSO-d 6 ,400 MHz) (1 :1 mixmre of diastereomers) δ = 8.15 (m, 2H); 8.5 (m, 3H); 7.20 (m, 2H); 6.95 (m, 2H); 4.75 (m, IH); 4.30 (m, IH); 3.05 (s, 3H); 2.95 (m, 2H); 2.90 (s, 3H); 1.75 and 1.65 (two d, 3H); 1.30 and 1.35 (two s, 9H). Example 31 Synthesis of N-(Toluene-4-sulfonyl)-L-(l,l-dioxo-5,5-dimethyl)- thiaprolyl-L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 29 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.75 (m, 3H), 7.29 (m, 4H), 7.08 (d, 2H), 4.95 (m, IH), 4.46-4.20 (m, 3H), 3.17 (s, 3H), 3.30-3.10 (m, 2H), 3.02 (s, 3H), 2.43 (s, 3H), 1.15 (s, 3H), 0.88 (s, 3H). 13 C NMR (CDC1 3 ): δ = 127.2, 167.5, 155.8, 150.3, 145.4, 133.6, 132.6, 130.8, 130.2, 128.3, 121.9, 67.9, 65.8, 60.8, 53.9, 36.8, 36.6, 35.8, 21.6, 18.8, 15.0. Example 32 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-prolyl-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 27 using the procedure described in Method 11. NMR data was as follows: 13 C NMR (CDC1 3 ): δ = 7.88-7.84 (m, 2H), 7.54 (d, IH), 7.26-7.18 (m, 4H), 7.01 (d, 2H), 6.92 (s, 3H), 4.88-4.83 (m, IH), 4.14-4.11 (m, IH), 3.39-3.29 (m, 2H), 3.13 (m, 2H), 3.00 (s, 3H), 2.99 (s, 3H), 1.92-1.89 (m, IH), 1.59-1.43 (m, 3H). 13 C NMR (CDC1 3 ): δ = 173.1 , 172.4, 165.6, 155.5, 150.4, 133.2, 131.9, 130.6, 130.3, 121.8, 116.6, 61.9, 53.1, 49.6, 36.6, 36.3, 30.2, 23.9. Example 33 Synthesis of N-(Toluene-4-sulfonyl)-D-prolyl-L-4- (4-methylpiperazin-l-yl)phenylalanine -butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: 13 C NMR (CDC1 3 ): δ = 7.72 (d, 2H), 7.33 (d, 3H), 7.17 (d, 2H), 7.02 (d, 2H), 4.71 (q, IH), 4.09-4.06 (m, IH), 3.67 (bs, 2H), 3.57 (bs, 2H), 3.41-3.34 (m, IH), 3.22 (dd, IH), 3.16-3.09 (m, IH), 3.03 (dd, IH), 2.46- 2.43 (m, 7H), 2.05-2.02 (m, IH), 1.57-1.43 (m, 3H), 1.47 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.8, 169.9, 153.6, 150.4, 144.3, 133.4, 133.1, 130.3, 130.0, 127.9, 121.6, 82.6, 62.3, 54.5, 53.8, 49.6, 46.1, 44.3, 43.7, 37.3, 29.7, 27.8, 24.1, 21.4. Example 34 Synthesis of N-(Toluene-4-sulfonyl)-N-methyI-L-alanyI-L-4-(4-methylpiperazin- l-ylcarbonyloxy)phenylaIanine f-butyl ester The title compound was prepared following the procedure outlined for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDCI 3 ): δ = 7.68 (d, 2H), 7.31 (d, 2H), 7.17 (d, 2H), 7.04 (d, 2H), 6.86 (d, IH), 4.65 (m, IH), 4.47 (q, IH), 3.71-3.53 (m, 4H), 3.24- 2.92 (m, 2H), 2.50-2.40 (m, 10H), 2.35 (s, 3H), 1.45 (s, 9H), 0.92 (d, 3H). 13 C NMR (CDC1 3 ): δ = 170.1, 169.9, 153.6, 150.4, 143.9, 135.6, 133.3, 130.2, 129.9, 127.2, 121.8, 82.4, 55.4, 54.6, 53.6, 46.0, 44.2, 43.7, 37.2, 29.6, 27.8, 21.4, 11.5. Example 35 Synthesis of N-(4-Nitrobenzenesulfonyl)-L-proIyl-L-4- (N,N-dimethyIcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 8.38-8.34 (m, 2H), 8.05-8.00 (m, 2H), 7.16- 2.12 (m, 2H), 7.03-6.94 (m, 3H), 4.74-4.68 (m, IH), 4.15-4.14 (m, IH), 3.41-3.32 (m, IH), 3,23-3.14 (m, 2H), 3.08 (s, 3H), 3.03 (m, IH), 2.98 (s, 3H), 2.05 (m, IH), 1.66-1.48 (m, 3H), 1.47 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.0, 169.9, 154.8, 150.6, 150.4, 142.4, 132.9, 130.2, 129.0, 124.5, 121.6, 82.7, 62.2, 53.4, 49.4, 37.0, 36.5, 36.2, 30.1 , 27.7, 24.1. Example 36 Synthesis of N-(Toluene-4-sulfonyl)-L-[(l,l-dioxo)- thiamorpholin-3-carbonyl]-L-4- (N,N-dimethylaminosulfonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described for the preparation of Example 21 and substitution of appropriate starting materials. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.73 (d, IH), 7.67 (d, IH), 7.35 (m, 2H), 7.27 (m, 2H), 6.88 (d, IH), 6.66 (d, IH), 5.08 (m, 0.5H), 4.97 (m, 0.5H), 4.71 (m, 0.5H), 4.61 (m, 0.5H), 4.25 (m, 0.5H), 4.03 (m, IH), 3.21-3.04 (m, H), 2.89 (s, 3H), 2.83 (s, 3H), 2.78 (m, 3H), 2.42 (s, 3H), 1.44 (s, 4.5H), 1.38 (s, 4.5H). 13 C NMR (CDC1 3 ): δ = 169.8, 169.6, 164.9, 164.5, 149.3, 149.1, 145.6, 145.4, 135.4, 135.0, 134.6, 130.9, 130.6, 130.5, 127.4, 127.2, 122.0, 121.8, 83.0, 83.0, 56.0, 53.7, 49.2, 49.1, 48.5, 41.9, 41.4, 38.6, 36.8, 36.2, 27.7, 21.5. Example 37 Synthesis of N-(Toluene-4-sulfonyl)sarcosyl-L-4- (thiomorpholin-4-ylcarbonyloxy)phenylalanine tert-Butyl Ester Substituting thiomoφholine for N-methylpiperazine, and following the method for the preparation of Example 4, gave the title compound. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.65 (d, 2H), 7.33 (d, 2H), 7.20 (d, 2H), 7.04 (d, 2H), 4.76 (m, IH), 3.89 (m, 4H), 3.68 (d, IH), 3.48 (d, IH), 3.10 (m, 2H), 2.66 (m, 7H), 2.41 (s, 3H), 1.43 (s, 9H). 13 C ΝMR (CDC1 3 ): δ = 169.9, 167.2, 153.5, 150.3, 144.3, 133.1, 130.3, 130.0, 127.6, 121.8, 82.5, 53.8, 53.3, 47.0, 36.4, 37.2, 36.6, 27.8, 27.3, 27.0, 21.4. Example 38 Synthesis of N-(Toluene-4-sulfonyl)-L-N-methylalanyl- L-4-(4-methylpiperazin-l-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 34 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.65 (d, 2H), 7.34 (d, 2H), 7.27 (d, 2H), 7.09 (d, 2H), 4.64-4.50 (m, 2H), 4.48-4.23 (m, 2H), 3.60-2.96 (m, 8H), 2.92 (s, 3H), 2.55 (s, 3H), 2.40 (s, 3H), 0.93 (d, 3H). 13 C NMR (CDCI 3 ): δ = 174.3, 173.1, 154.9, 151.6, 145.5, 137.0, 136.1, 131.6, 131.2, 128.5, 123.1 , 56.4, 54.8, 54.0, 43.8, 37.3, 30.2, 21.5, 13.2. Example 39 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl- L-4-(l , l-dioxothiomorpholin-4-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 81 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 8.03 (m, IH), 7.73 (d, 2H), 7.41 (d, 2H), 7.28 (d, 2H), 7.08 (d, 2H), 4.70-4.65 (m, IH), 4.12-4.00 (m, 5H), 3.38-3.36 (m, IH), 3.31-3.06 (m, 7H), 2.43 (s, 3H), 1.77-1.48 (m, 5H). 13 C NMR (CD 3 OD): δ = 168.4, 159.1, 130.0, 129.1, 125.6, 125.1, 123.0, 116.9, 57.2, 48.8, 46.3, 44.5, 31.5, 25.6, 19.3, 15.4. Example 40 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (thiomorpholin-4-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 82 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.73 (d, 2H), 7.41 (d, 2H), 7.27 (d, 2H), 7.04 (d, 2H), 4.68-4.65 (m, IH), 4.10-4.07 (m, IH), 3.90 (t, 2H), 3.77 (t, 2H), 3.38-3.11 (m, 4H), 2.66 (m, 4H), 2.43 (s, 3H), 1.80-1.48 (m, 5H). 13 C NMR (CD 3 OD): δ = 168.4, 168.2, 149.4, 145.7, 139.8, 129.7, 129.0, 125.6, 125.1, 123.1, 116.9, 57.2, 48.8, 44.6, 42.1, 36.0, 31.4, 25.7, 22.1, 21.8, 19.3, 15.4. Example 41 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI- L-4-(isonipecotoyloxy)phenylalanine The title compound was prepared from the product of Example 80 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 8.08 (m, IH), 7.73 (d, 2H), 7.41 (d, 2H), 7.27 (d, 2H), 7.03 (d, 2H), 4.71 (m, IH), 4.11-4.08 (m, IH), 3.61 (t, 2H), 3.47- 3.38 (m, 3H), 3.31-3.11 (m, 4H), 2.43 (s, 3H), 1.77-1.47 (m, 10H). 13 C NMR (CD 3 OD): δ = 168.3, 168.1, 158.8, 149.6, 145.9, 139.8, 129.5, 129.0, 125.6, 125.1, 123.1, 116.9, 57.2, 48.6, 44.6, 40.6, 40.1, 36.0, 31.4, 25.7, 20.9, 20.6, 19.3. Example 42 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (pyrrolidin-l-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 83 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 8.08 (m, IH), 7.73 (d, 2H), 7.41 (d, 2H), 7.04 (d, 2H), 7.27 (d, 2H), 4.72-4.68 (m, IH), 4.11-4.08 (m, IH), 3.57-3.53 (t, 2H), 3.43-3.28 (m, 3H), 3.25-3.06 (m, 4H), 2.43 (s, 3H), 1.99-1.80 (m, 4H), 1.78-1.49 (m, 5H). 13 C NMR (CD 3 OD): δ = 168.2, 158.3, 149.2, 145.8, 139.8, 129.4, 129.1, 125.6, 125.1, 123.1, 116.9, 57.2, 48.7, 44.5, 41.5, 31.4, 25.7, 20.6, 19.8, 19.3, 15.4. Example 43 Synthesis of N-(Toluene-4-suIfonyl)-L-prolyl-L-4- (morpholin-4-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 108 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.73 (d, 2H), 7.41 (d, 2H), 7.27 (d, 2H), 7.04 (d, 2H), 4.95-4.93 (m, IH), 4.10-4.07 (m, IH), 3.71-3.65 (m, 6H), 3.50 (t, 2H), 3.40-3.10 (m, 4H), 2.43 (s, 3H), 1.78-1.48 (m, 4H). 13 C NMR (CD 3 OD): δ = 168.4, 168.2, 149.6, 145.7, 139.8, 129.1, 125.6, 125.1, 123.1, 116.8, 61.5, 57.2, 44.5, 36.0, 31.4, 25.6, 19.3, 15.4. Example 44 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI-L-4- (4-methylpiperazin-l-ylcarbonyloxy)phenylalanine Neopentyl Ester Titanium isopropoxide (0.3 equivalents) was added to Tos-Pro-Tyr ethyl ester (1 equivalent) and an excess of neopentyl alcohol. The mixmre was heated to reflux under an argon atmosphere overnight. Excess neopentyl alcohol was removed under reduced pressure and the residue purified by flash column chromatography (silica, hexane: EtOAc 2: 1) to give the neopentyl ester a white solid (0.9g, 85 %). The title compound was prepared following the procedure described in Example 4. NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHz) δ = 8.29 (d, IH, J=7.91Hz); 7.68 (d, 2H, J=8.45Hz); 7.40 (d, 2H, J=8.34Hz); 7.24 (d, 2H, J = 8.57Hz); 7.00 (d, 2H, J = 8.57Hz); 4.56 (m, IH); 4.07 (m, IH); 3.73 (s, 2H); 3.55 (br s, 2H); 3.40 (m, 3H); 3.10 (m, 3H); 2.40 (s, 3H); 2.35 (br s, 4H); 2.20 (s, 3H); 1.55 (m, 3H); 1.37 (m, IH); 0.85 (s, 9H). Example 45 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine Neopentyl Ester Titanium isopropoxide (0.3 equivalents) was added to Tos-Pro-Tyr ethyl ester (1 equivalent) and an excess of neopentyl alcohol. The mixmre was heated to reflux under an argon atmosphere overnight. Excess neopentyl alcohol was removed under reduced pressure and the residue purified by flash column chromatography (silica, hexane: EtOAc 2: 1) to give the neopentyl ester a white solid (0.9g, 85%). The title compound was prepared following the procedure described in Example 2. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz) δ = 8.28 (d, IH, J=8.13Hz); 7.68 (d, 2H, J = 8.4Hz); 7.40 (d, 2H, J=7.9Hz); 7.23 (d, 2H, J=8.56Hz), 6.99 (d, 2H, J = 8.35Hz); 4.57 (m, 3H); 2.40 (s, 3H); 1.55 (m, 3H); 1.38 (m, IH); 0.85 (s, 9H). Example 46 Synthesis of 2-(Saccharin-2-yl)propionoyl-L-4- (4-methylpiperazin-l-ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described in Preparative Example A and Example 4. NMR data was as follows: Η NMR (DMSOΛ, 400 MHz) (1:1 mixmre of diastereomers) δ = 8.31 (m, IH); 8.26 (m, IH); 8.03 (m, 3H); 7.20 (m, 2H); 7.00 (m, 2H); 4.73 (m, IH); 4.30 (m, IH); 3.58 (br s, 2H); 3.40 (br s, 2H); 3.02 (m, IH); 2.95 (m, IH); 2.35 (br s, 4H); 2.20 (s, 3H); 2.75 and 2.65 (two d, 3H); 1.35 and 1.32 (two s, 9H). Example 47 Synthesis of 2-(Saccharin-2-yl)propionoyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Preparative Example A using the procedure described in Method 11. NMR data was as follows: 'H NMR (DMSO-dg, 400 MHz) (1: 1 mixmre of diastereomers) δ = 12.75 (br s, IH); 8.28 (m, 2H); 8.05 (m, 3H); 7.20 (m, 2H); 7.00 and 9.95 (two d, 2H); 4.75 (m, IH); 4.40 (m, IH); 3.10 (m, IH); 3.05 (s, 3H); 2.95 (m, IH); 2.90 (s, 3H); 2.75 and 2.60 (two d, 3H). Example 48 Synthesis of N-(Toluene-4-sulfonyl)-L-N-methylalanyl-L-4- (N,N-dimethyIcarbamyloxy)phenylaIanine tert-Butyl Ester The title compound was prepared following the procedure for the synthesis of Example 2 with the substimtion of appropriate starting materials. NMR data was as follows: 'H NMR (CDC1 3 ): δ = 7.68 (d, 2H), 7.31 (d, 2H), 7.17 (d, 2H), 7.04 (d, 2H), 6.87 (d, 2H), 4.67 (m, IH), 4.48 (q, IH), 3.09 (s, 3H), 3.00 (s, 3H), 3.14-2.92 (m, 2H), 2.46 (s, 3H), 2.43 (s, 3H), 1.45 (s, 9H), 0.92 (d, 3H). 13 C NMR (CDC1 3 ): δ = 170.2, 169.9, 154.9, 150.6, 143.9, 135.6, 133.2, 130.2, 130.0, 127.3, 121.9, 82.5, 55.5, 53.7, 37.2, 36.6, 36.4, 29.7, 27.8, 21.4, 11.5. Example 49 Synthesis of N-(Toluene-4-sulfonyl)-L-(thiamorpholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester L-Thiamoφholine-3 -carboxylic acid was prepared by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). N-(Toluene- 4-sulfonyl)-L-thiamoφholine-3-carboxylic acid was prepared using the procedure described in Method 1. The title compound was prepared following the procedure for the synthesis of Example 2 with substimtion of appropriate starting materials. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.69 (d, 2H), 7.31 (d, 2H), 7.16 (d, 2H), 6.98 (d, 2H), 6.86 (d, IH), 4.71 (m, IH), 4.62 (m, IH), 3.94 (m, IH), 3.31 (m, IH), 3.09 (m, 4H), 2.98 (s, 3H), 2.67 (m, IH), 2.50 (m, IH), 2.40 (s, 3H), 2.31 (m, IH), 2.10 (m, IH), 1.49 (s, 9H). 13 C ΝMR (CDC1 3 ): δ = 169.9, 167.4, 154.8, 150.6, 144.2, 136.8, 132.8, 130.4, 130.2, 127.3, 121.8, 82.6, 55.2, 54.0, 43.3, 36.5, 36.3, 27.8, 25.2, 24.6, 21.4. Example 50 Synthesis of N-(Toluene-4-sulfonyl)sarcosyl- L-4-(l , l-dioxothiomorpholin-4-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 121 using the procedure described in Method 11. ΝMR data was as follows: Η ΝMR (CD 3 OD): δ = 7.67 (d, 2H), 7.40 (d, 2H), 7.27 (d, 2H), 7.09 (d, 2H), 4.61 (m, IH), 4.12 (m, 2H), 3.99 (m, 2H), 3.60 (m, 2H), 3.23 (m, 8H), 2.58 (s, 3H), 2.42 (s, 3H). 13 C ΝMR (CD 3 OD): δ = 174.2, 170.3, 155.0, 151.6, 145.6, 136.1, 135.2, 131.5, 131.1, 128.9, 123.0, 54.6, 54.0, 52.4, 52.2, 44.4, 44.0, 37.4, 36.8, 21.4. Example 51 Synthesis of N-(Toluene-4-sulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N,iV-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared from the product of Example 49 following the procedure described by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522). NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.76 (d, 2H), 7.37 (d, 2H), 7.08 (d, 2H), 6.98 (d, 2H), 6.56 (d, IH), 4.95 (m, IH), 4.62 (m, IH), 3.99 (m, 2H), 3.25 (m, IH), 3.07 (s, 3H), 2.97 (m, 8H), 2.44 (s, 3H), 1.48 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.0, 164.8, 154.9, 150.7, 145.4, 135.3, 132.6, 130.7, 130.3, 127.5, 122.3, 82.8, 56.1, 53.6, 49.5, 48.6, 41.6, 36.6, 36.4, 27.9, 21.6. Example 52 Synthesis of N-(Toluene-4-sulfonyl)-L-(l , l-dioxothiamorpholin-3-carbonyl)- L-4-(morpholin-4-ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 71. NMR data was as follows: Η NMR (CDCI 3 ): δ = 7.75 (d, 2H), 7.36 (d, 2H), 7.12 (d, 2H), 6.98 (d, 2H), 6.58 (d, IH), 4.93 (m, IH), 4.63 (m, IH), 4.09 (m, 2H), 3.72 (m, 4H), 3.63 (m, 2H), 3.51 (m, 2H), 3.24 (m, IH), 2.96 (m, 4H), 2.43 (s, 3H), 1.46 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.0, 164.8, 153.7, 150.4, 145.4, 135.2, 132.9, 130.7, 130.4, 127.5, 122.1, 82.9, 66.4, 56.1 , 53.6, 49.4, 48.5, 44.7, 43.9, 41.6, 36.3, 27.8, 21.6. Example 53 Synthesis of N-(Toluene-4-sulfonyl)-L-N-methyIalanyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 48 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.68 (d, 2H), 7.31 (d, 2H), 7.20 (d, 2H), 7.11- 7.04 (m, 3H), 6.35 (br s, IH), 4.81 (m, IH), 4.52 (q, IH), 3.35-2.98 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 2.45 (s, 3H), 2.43 (s, 3H), 0.91 (d, 3H). 13 C NMR (CDC1 3 ): δ = 173.7, 170.8, 155.2, 150.6, 144.0, 135.4, 133.2, 130.2, 130.0, 127.3, 122.1 , 55.5, 53.2, 36.6, 36.5, 36.4, 29.8, 21.4, 11.6. Example 54 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(thiamorpholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester L-Thiamoφholine-3-carboxylic acid was prepared by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). N-(Toluene- 4-sulfonyl)-L-thiamoφholine-3-carboxylic acid was prepared using the procedure described in Method 1. The title compound was then prepared following the procedure for the synthesis of Example 2. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.87-7.82 (m, 2H), 7.20 (t, 2H), 7.16 (d, 2H), 7.00 (d, 2H), 6.76 (d, IH), 4.74 (t, IH), 4.65 (q, IH), 3.92 (d, IH), 3.32 (dd, IH), 3.17-3.00 (m, 2H), 3.09 (s, 3H), 2.99 (s, 3H), 2.76-2.66 (m, IH), 2.62 (dd, IH), 2.46 (dt, IH), 2.22 (d, IH), 1.49 (s, 9H). 13 C ΝMR (CDCI 3 ): δ = 170.0, 167.2, 165.5, 154.8, 150.7, 135.8, 132.7, 130.5, 130.1, 121.9, 116.9, 82.8, 55.3, 53.9, 43.4, 36.6, 36.4, 36.3, 27.9, 25.8, 25.0. Example 55 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N,iV-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared from the product of Example 54 following the procedure described by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522). NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.92-7.88 (m, 2H), 7.24 (t, 2H), 7.09 (d, 2H), 6.97 (d, 2H), 6.41 (d, IH), 4.96 (d, IH), 4.62 (d, IH), 4.03 (d, IH), 3.26 (dd, IH), 3.13-2.92 (m, 6H), 3.09 (s, 3H), 2.97 (s, 3H), 1.49 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.1, 165.9, 164.5, 154.9, 150.7, 134.0, 132.4, 130.5, 130.4, 122.2, 117.3, 83.0, 56.1, 53.4, 50.0, 49.1, 41.7, 36.6, 36.3, 36.1, 27.9. Example 56 Synthesis of N-(Pyridine-3-sulfonyl)-L-prolyI-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester N-Benzyl-L-proline was coupled to L-tyrosine t-butyl ester using the procedure described in Method 12. N-Benzyl-L-prolyl-L-(NN- dimethylcarbamyloxy)phenyl-alanine t-butyl ester was prepared following the procedure described for the preparation of Example 2 . L-Prolyl-L-(4-NN- dimethylcarbamyloxy)phenylalanine t-butyl ester was prepared from the product of the previous reaction using the procedure described in Method 4. The title compound was prepared using the procedure described for the preparation of 3-pyridine sulfonyl chloride (see Crowell, et al., J. Med. Chem., 1989, 32, 2436-2442) and the product of the last reaction. ΝMR data was as follows: Η ΝMR (CDClj): δ = 9.95 (d, IH), 8.83 (dd, IH), 8.14-8.10 (m, IH), 7.51-7.47 (m, IH), 7.16-7.13 (m, 3H), 7.02-6.99 (m, 2H), 4.72-4.69 (m, IH), 4.09-4.06 (m, IH), 3.41-3.39 (m,lH), 3.23-3.17 (m, IH), 3.13-2.98 (m, IH), 3.07 (s, 3H), 2.97 (s, 3H), 2.04 (m, IH), 1.59-1.47 (m, 3H), 1.45 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.1, 169.9,154.8, 153.9, 150.5, 148.4, 135.5, 133.0, 130.1, 123.9, 121.6, 82.6, 52.2, 53.6, 49.5, 37.1, 36.5, 36.3, 29.9, 27.8, 24.0. Preparative Example B Synthesis of N-(Pyrimidine-2-sulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared by substituting 2-pyrimidine sulfonyl chloride (see Skulnick, et al., J. Med. Chem., 1997, 40, 1149-1164) and following the method for the preparation of Example 56. NMR data was as follows: Η NMR (CDCI 3 ): δ = 8.28 (d, 2H), 7.39 (d, IH), 7.02 (d, 2H), 6.88 (d, 2H), 6.54 (m, IH), 4.76-4.69 (m, IH), 4.57-4.55 (m, IH), 3.64 (m, IH), 3.55-3.52 (m, IH), 3.09-3.03 (m, IH), 3.08 (s, 3H), 2.99-2.95 (m, IH), 2.98 (s, 3H), 2.32 (m, IH), 2.01-1.97 (m, 3H), 1.37 (s, 9H). 13 C NMR (CDC1 3 ): δ = 172.1, 170.4, 160.6, 157.7, 154.8, 150.3, 133.0, 130.1, 121.3, 110.5, 82.0, 60.7, 53.3, 47.5, 37.1, 36.5, 36.3, 28.9, 27.7, 24.1. Example 57 Synthesis of iV-(4-Nitrobenzenesulfonyl)-L-prolyl-L-4- (N,ZV-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 35 using the procedure described in method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 8.36 (d, 2H), 8.02 (d, 2H), 7.42 (d, IH), 7.20 (d, 2H), 7.01 (d, 2H), 4.86 (m, IH), 4.18-4.15 (m, IH), 3.46-3.43 (m, IH), 3.32-3.26 (m, IH), 3.19-3.11 (m, 2H), 3.09 (s, 3H), 3.01 (s, 3H), 1.91 (m, IH), 1.65-1.54 (m, 3H). 13 C NMR (CDCI 3 ): δ = 172.9, 171.7, 155.5, 150.4, 150.4, 142.1, 133.2, 130.5, 129.1, 124.6, 121.8, 61.9, 52.9, 49.6, 36.6, 36.3, 36.3, 30.6, 24.1. Example 58 Synthesis of N-(4-Cyanobenzenesulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDCI 3 ): δ = 7.94 (d, 2H), 7.82 (d, 2H), 7.13 (d, 2H), 7.05- 6.99 (m, 3H), 4.71-4.66 (m, IH), 4.12-4.09 (m, IH), 3.36-3.35 (m, IH), 3.22-3.11 (m, 2H), 3.07 (s, 3H), 3.06-3.01 (m, IH), 2.97 (s, 3H), 2.05 (m, IH), 1.63-1.37 (m, 3H), 1.46 (s, 9H). 13 C NMR (CDCI 3 ): δ = 170.1 , 169.9, 154.8, 150.6, 140.8, 133.1, 132.9, 130.2, 128.4, 121.7, 117.1 , 116.9, 82.7, 62.2, 53.4, 49.4, 37.0, 36.5, 36.3, 30.1, 27.8, 24.1. Example 59 Synthesis of N-(Toluene-4-sulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N,N-dimethylaminosulfonyloxy)phenylalanine The title compound was prepared from the product of Example 36 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.79 (m, 2H), 7.44 (m, 2H), 7.27 (m, 2H), 7.17 (m, 2H), 5.21 (m, IH), 4.64 (m, IH), 4.14 (m, IH), 3.61 (m, 2H), 3.24 (m, 2H), 3.08 (m, 2H), 2.89 (s, 6H), 2.80 (m, 2H), 2.43 (s, 3H). 13 C NMR (CD 3 OD): δ = 173.9, 168.1 , 168.0, 150.8, 150.8, 146.7, 146.5, 137.6, 137.5, 137.1, 136.9, 132.2, 132.1, 131.7, 131.6, 128.8, 123.3, 123.1, 57.3, 54.8, 51.0, 50.8, 50.5, 47.9, 47.8, 43.2, 43.0, 39.0, 39.0, 37.4, 37.0, 21.5. Example 60 Synthesis of N-(Toluene-4-sulfonyl)-L-(l , l-dioxothiamorpholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 51 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.79 (d, 2H), 7.43 (d, 2H), 7.20 (d, 2H), 7.00 (d, 2H), 5.21 (m, IH), 4.65 (m, IH), 4.12 (m, IH), 3.75 (m, IH), 3.29 (m, 3H), 3.08 (s, 3H), 3.00 (m, IH), 3.00 (m, IH), 2.97 (s, 3H), 2.80 (m, 3H), 2.44 (s, 3H). 13 C NMR (CDC1 3 ): δ = 165.1, 159.0, 147.9, 143.1, 137.6, 128.6, 126.1, 122.7, 122.6, 119.8, 114.3, 48.3, 45.8, 41.6, 34.0, 28.0, 27.8, 27.7, 12.5. Example 61 Synthesis of N-(Toluene-4-sulf onyl)-L-(l , l-dioxo)thiaprolyl- L-4-(N,/V-dimethylcarbamyloxy)phenyIalanine tert-Butyl Ester The title compound was prepared from N-(toluene-4-sulfonyl)-L- thiaprolyl-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester, prepared as per the examples herein, following the procedure described by by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522). ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.77 (d, 2H), 7.38 (d, 2H), 7.18 (m, 3H), 7.09 (d, 2H), 4.83-4.57 (m, 3.H), 3.77-3.60 (m, 2H), 3.36-3.23 (m, IH), 3.15- 3.00 (m, 7H), 2.85-2.73 (m, IH), 2.46 (s, 3H), 1.50 (s, 9H). Example 62 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.96 (d, 2H), 7.80 (d, 2H), 7.26-7.13 (m, 3H), 7.01 (d, 2H), 4.72-4.70 (m, IH), 4.11-4.08 (m, IH), 3.40-3.37 (m, IH), 3.25-3.10 (m, 2H), 3.07 (s, 3H), 3.04-3.02 (m, IH), 2.98 (s, 3H), 2.06 (m, IH), 2.06-2.04 (m, IH), 1.61-1.52 (m, 3H), 1.46 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.3, 169.9, 154.9, 150.6, 139.9, 134.9, 133.1, 130.2, 128.4, 126.5, 121.7, 82.7, 62.3, 5.35, 49.6, 37.2, 36.6, 36.3, 30.0, 27.8 24.1. Example 63 Synthesis of N-(l-Methylpyrazolyl-4-sulfonyl)-L-prolyl-L-4- (N,iV-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 117 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDCI 3 ): δ = 8.84 (br s, IH), 7.93 (s, IH), 7.79 (s, IH), 7.68-7.65 (m, IH), 7.18 (d, 2H), 6.99 (d, 2H), 4.88-4.81 (m, IH), 4.08- 4.06 (m, IH), 3.92 (s, 3H), 3.45-3.40 (m, IH), 3.34-3.27 (m, IH), 3.11- 3.01 (m, 5H), 2.97 (s, 3H), 1.82 (m, IH), 1.66-1.57 (m, 2H), 1.45 (m, IH). 13 C NMR (CDCI 3 ): δ = 173.1, 172.9, 159.1, 158.6, 150.4, 138.8, 133.4, 133.2, 130.3, 121.9, 117.3, 62.0, 53.1, 49.7, 39.4, 36.6, 36.5, 36.4, 30.4, 23.9. Example 64 Synthesis of N-(Toluene-4-sulfonyl)-L-(l , l-dioxo)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 61 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 8.34 (d, IH), 7.70 (d, 2H), 7.33 (d, 2H), 7.14 (d, 2H), 7.01 (d, 2H), 5.07 (m, IH), 4.93 (m, IH), 4.43 (d, IH), 4.01 (d, IH), 3.68 (m, IH), 3.37 (m, IH), 3.17 (s, 3H), 3.14 (m, IH), 3.09 (s, 3H), 2.54 (m, IH), 2.43 (s, 3H). 13 C NMR (CDC1 3 ): δ = 171.5, 166.4, 156.4, 150.5, 145.5, 134.2, 134.1, 131.4, 130.3, 128.1, 121.8, 64.3, 59.2, 53.7, 50.5, 36.9, 36.5, 35.8, 21.6. Example 65 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 84 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDCI 3 ): δ = 7.83 (m, 2H), 7.73 (d, IH), 7.16 (m, 4H), 6.99 (d, 2H), 5.57 (br s, IH), 4.87 (m, IH), 4.76 (m, IH), 4.53 (d, IH), 4.10 (d, IH), 3.34 (m, IH), 3.22 (d, 2H), 3.12 (s, 3H), 3.04 (s, 3H), 2.43 (m, IH). 13 C NMR (CDCI 3 ): δ = 172.1, 168.7, 155.7, 150.5, 133.6, 133.1, 130.8, 130.7, 121.7, 116.9, 116.6, 65.3, 53.3, 51.3, 36.8, 36.4, 36.1, 33.4. Example 66 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)- thiaprolyl-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 with the substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.91 (m, 2H), 7.26 (m, 4H), 7.02 (d, 2H), 6.96 (d, IH), 4.75 (m, IH), 4.55 (d, IH), 4.42 (d, IH), 3.86 (s, IH), 3.08 (s, 3H), 3.05 (m, 2H), 3.00 (s, 3H), 1.43 (s, 9H), 1.17 (s, 3H), 1.16 (s, 3H). 13 C NMR (CDC1 3 ): δ = 169.9, 168.1, 167.6, 164.2, 154.9, 150.6, 133.1, 132.2, 131.0, 130.9, 130.4, 121.7, 116.9, 116.6, 82.7, 73.5, 54.7, 53.7, 50.5, 37.8, 36.6, 36.4, 29.1, 27.8, 23.8. Example 67 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(l , 1-dioxothiamorpholin- 3-carbonyl)-L-4-(l , 1 -dioxothiomorpholin- 4-ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 68. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.91-7.87 (m, 2H), 7.27-7.25 (m, 2H), 7.15 (d, 2H), 6.51 (d, IH), 4.93-4.90 (m, IH), 4.64 -4.58 (m, IH), 4.14-3.99 (m, 7H), 3.28-2.90 (m, 10H), 1.47 (s, 9H). 13 C NMR (CDCI 3 ): δ = 170.1, 167.6, 164.5, 153.1, 149.8, 133.9, 133.4, 130.7, 130.5, 121.7, 117.4, 117.1, 83.1, 56.1 , 53.4, 51.6, 49.9, 48.9, 43.1, 41.6, 36.2, 27.8. Example 68 Synthesis of N-(Toluene-4-sulfonyl)-L-(l , 1-dioxothiamorpholin- 3-carbonyl)-L-4-(l , 1-dioxothiomorpholin- 4-ylcarbonyloxy)phenylalanine tert-Butyl Ester Substimting thiomoφholine for N-methylpiperazine, and following the method for the preparation of Examples 4 and oxidation of the sulfur group in the thiomoφholino ring per by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522) gave the title compound as a white solid. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.75 (d, 2H), 7.35 (d, 2H), 7.17 (d, 2H), 6.99 (d, 2H), 6.65 (d, IH), 4.92-4.90 (m, IH), 4.63-4.60 (m, IH), 4.15-3.95 (m, 7H), 3.30-3.23 (m, IH), 3.14 (t, 4H), 3.07-2.80 (m, 6H), 2.45 (s, 3H), 1.48 (s, 9H). 13 C ΝMR (CDC1 3 ): δ = 169.9, 164.8, 153.1 , 149.8, 145.5, 135.1, 133.6, 130.7, 127.5, 121.8, 82.9, 60.3, 56.1, 53.7, 51.8, 49.3, 48.4, 43.1, 42.7, 41.5, 36.3, 27.8, 21.5. Example 69 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-prolyl- L-4-(thiomorpholin-4-ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described in Example 37 and substimtion of appropriate starting materials. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.88-7.83 (m, 2H), 7.26-7.15 (m, 5H), 7.01 (d, 2H), 4.74-4.67 (m, IH), 4.08-4.05 (m, IH), 3.91-3.80 (m, 4H), 3.41-3.35 (m, IH), 3.24-3.00 (m, 3H), 2.70-2.65 (t, 4H), 2.06-2.04 (m, IH). 1.60- 1.46 (m, 12H). 13 C ΝMR (CDC1 3 ): δ = 170.5, 169.8, 153.4, 150.2, 133.5, 130.7, 130.5, 130.3, 121.6, 116.8, 116.5, 82.6, 62.2, 53.6, 49.6, 47.0, 46.4, 37.2, 29.8, 27.8, 27.3, 27.0, 24.1. Example 70 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)- thiaprolyl-L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 66 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.90 (m, 2H), 7.30-7.14 (m, 5H), 7.02 (d, 2H), 5.83 (br s, IH), 4.90 (m, IH), 4.57 (d, IH), 4.40 (d, IH), 3.96 (s, IH), 3.09 (s, 3H), 3.28-3.02 (m, 2H), 3.00 (s, 3H), 1.13 (s, 6H). 13 C NMR (CDC1 3 ): δ = 173.2, 169.2, 164.2, 163.9, 155.3, 150.6, 133.1, 132.0, 131.0, 130.9, 130.6, 122.0, 117.0, 116.7, 73.3, 54.6, 53.3, 50.5, 37.0, 36.7, 36.4, 29.0, 23.7. Example 71 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(l , l-dioxothiamorpholin-3- carbonyl)-L-4-(morpholin-4-ylcarbonyloxy)phenylalanine tert-Butyl Ester Substituting 4-moφholinecarbamyl chloride for dimethylcarbamyl chloride, and following the methods for the preparation of Example 2, gave the title compound as a white solid. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.91-7.87 (m, 2H), 7.26-7.20 (m, 2H), 7.11 (d, 2H), 6.98 (d, 2H), 6.43 (d, IH), 4.95-4.92 (m, IH), 4.62-4.60 (m, IH), 4.05-4.00 (m, 2H), 3.74 (t, 4H), 3.66-3.52 (m, 4H), 3.30-2.92 (m, 6H), 1.48 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.1, 164.5, 150.4, 134.6, 132.7, 130.5, 122.0, 117.4, 117.1, 83.1, 66.5, 56.1, 53.4, 49.9, 49.0, 44.7, 44.0, 41.6, 36.2, 27.8. Example 72 Synthesis of N-(4-TrifluoromethoxybenzenesulfonyI)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ - 7.89 (d, 2H), 7.35 (d, 2H), 7.25-7.13 (m, 3H), 7.01 (d, 2H), 4.70 (m, IH), 4.09-4.06 (m, IH), 3.39-3.36 (m, IH), 3.24- 3.01 (m, 5H), 2.98 (s, 3H), 2.05 (m, IH), 1.62-1.47 (m, 3H), 1.46 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.4, 169.9, 154.9, 152.7, 150.6, 134.6, 113.2, 130.2, 130.1, 121.7, 120.2, 82.7, 62.2, 53.6, 49.6, 37.2, 36.6, 36.3, 29.9, 27.8, 24.1. Example 73 Synthesis of N-(Toluene-4-sulfonyl)-L-(l , l-dioxothiamorpholin-3- carbonyl)-L-4-(N,iV-dimethylcarbamyloxy)phenylalanine Isopropyl Ester Following the method for the preparation of Example 2 and oxidation of the sulfur group in the thiomoφholino ring per by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522) gave the title compound. NMR data was as follows: Η NMR (CDCI 3 ): δ = 7.70 (d, 2H), 7.31 (d, 2H), 7.04 (d, 2H), 6.93 (d, 2H), 6.59 (d, IH), 5.01 (m, 2H), 4.65 (m, IH), 4.01 (d, IH), 3.90 (d, IH), 3.25 (m, IH), 3.00 (s, 3H), 2.82 (m, 8H), 2.37 (s, 3H), 1.22 (s, 3H), 1.20 (s, 3H). 13 C NMR (CDC1 3 ): δ = 170.3, 165.0, 154.6, 150.5, 145.1, 135.2, 132.3, 130.4, 130.0, 127.2, 122.1, 69.5, 55.9, 53.1, 49.1, 48.5, 41.4, 36.3, 36.1, 35.9, 21.4. Example 74 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(l,l-dioxo-5,5-dimethyl)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared from the product of Example 66 following the procedure described by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522). NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.88 (m, 2H), 7.24 (m, 4H), 7.05 (d, 2H), 6.95 (d, IH), 4.80 (m, IH), 4.40 (m, 2H), 4.10 (s, IH), 3.17-3.03 (m, 2H), 3.10 (s, 3H), 3.01 (s, 3H), 1.47 (s, 9H), 1.36 (s, 3H), 1.11 (s, 3H). 13 C NMR (CDC1 3 ): δ = 169.8, 168.6, 166.0, 154.5, 150.8, 139.7, 133.0, 131.5, 131.4, 130.3, 122.0, 117.1 , 116.8, 83.0, 68.0, 60.9, 59.3, 53.8, 37.4, 36.6, 36.4, 27.8, 18.9, 18.8. Example 75 Synthesis of N-(Toluene-4-sulfonyl)-L-(l,l-dioxo-5,5-dimethyl)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared from the product of Example 11 following the procedure described by Larsson and Carlson (Acta Chemica Scan. 1994, 48, 522). NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.75 (d, 2H), 7.38 (d, 2H), 7.21 (d, 2H), 7.03 (m, 3H), 5.08 (m, IH), 4.89 (m, IH), 4.38 (m, 2H), 4.10 (s, IH), 3.22- 3.04 (m, 2H), 3.10 (s, 3H), 3.00 (s, 3H), 2.43 (s, 3H), 1.26 (m, 9H), 1.09 (s, 3H). 13 C NMR (CDC1 3 ): δ = 170.3, 166.3, 150.8, 145.9, 132.8, 131.9, 130.3, 128.6, 122.0, 69.8, 68.0, 60.9, 59.4, 53.4, 37.4, 36.6, 36.4, 21.6, 21.5, 19.2, 18.6. Example 76 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 74 using the procedure described in Method 11. NMR data was as follows: 13 C NMR (CDC1 3 ): δ = 171.7, 167.9, 137.3, 164.5, 155.9, 150.4, 133.6, 131.8, 131.3, 131.2, 130.8, 121.9, 117.1, 116.8, 67.8, 60.9, 59.9, 53.8, 36.8, 36.6, 36.0, 19.1, 19.0. Example 77 Synthesis of N-(Pyrimidine-2-sulfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Preparative Example B using the procedure described in Method 11. NMR data was as follows: ! H NMR (CDC1 3 ): δ = 8.45 (br m, 2H), 8.22 (br s, IH), 7.55 (d, IH), 7.11 (d, 2H), 6.95 (d, 2H), 6.81 (m, IH), 4.80-4.74 (m, 2H), 3.70 (m, IH), 3.55 (m, IH), 3.20-3.08 (m, 4H), 2.98 (s, 3H), 2.89-2.76 (m, IH), 2.13- 1.96 (m, 3H), 1.60 (m, IH). 13 C NMR (CDC1 3 ): δ = 190.0, 173.6, 171.0, 155.2, 153.9, 150.6, 133.2, 130.1, 121.9, 110.3, 62.0, 55.1, 48.2, 36.6, 36.6, 36.3, 30.2, 23.4. Example 78 Synthesis of N-(Toluene-4-sulfonyl)-L-(l,l-dioxothiamorpholin-3- carbonyl)-L-4-(4-methylpiperazin-l-ylcarbonyloxy)phenylalanine tert-Butyl Ester Following the method for the preparation of Example 4 and oxidation of the sulfur group in the thiamoφholino ring per Larsson and Carlson (Acta Chemica Scan. 1994, 48., 522) gave the title compound. NMR data was as follows: Η NMR (CDCI 3 ): δ = 7.76 (d, 2H), 7.37 (d, 2H), 7.12 (d, 2H), 6.96 (d, 2H), 6.57 (d, IH), 4.95 (m, IH), 4.62 (m, IH), 4.03 (m, 2H), 3.67 (m, 4H), 3.25 (m, IH), 2,89 (m, 4H), 2.45 (m, 6H), 2.35 (s, 3H), 1.48 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.0, 164.8, 153.7, 150.5, 145.4, 135.3, 132.8, 130.7, 130.4, 127.5, 122.2, 82.9, 56.2, 54.6, 54.5, 53.6, 49.5, 48.6, 46.0, 44.2, 43.7, 41.6, 36.3, 27.9, 21.6. Example 79 Synthesis of N-(4-Fluorobenzenesulfonyl)-L- (l,l-dioxo)thiaprolyl-L-4-(N,/V-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 85 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ = 4.98, (m, IH), 4.90 (m, IH), 4.44 (d, IH), 4.03 (d, IH), 3.67 (m, IH), 3.37(m, IH), 3.25-3.02 (m, IH), 3.20 (s, 3H), 3.11 (s, 3H), 2.68 (m, IH). 13 C NMR (CDC1 3 ): δ = 171.7, 167.9, 166.3, 164.4, 157.0, 156.4, 150.5, 139.6, 134.0, 133.1, 131.3, 131.1, 130.9, 121.9, 117.2, 116.9, 64.1, 58.8, 53.7, 50.6, 36.9, 36.5, 35.6. Example 80 Synthesis of ZV-(Toluene-4-sulfonyl)-L-prolyl-L-4- (isonipecotoyloxy)phenylalanine tert-Butyl Ester Substituting piperazine for N-methylpiperazine, and following the methods for the preparation of Example 4, gave the title compound as a white solid. ΝMR data was as follows: 13 C ΝMR (CDCI 3 ): δ = 7.70 (d, 2H), 7.32-7.26 (m, 2H), 7.14 (d, 2H), 7.01 (d, 2H), 4.72-4.68 (m, IH), 4.07-4.05 (m, IH), 3.60-3.49 (m, 4H), 3.37-3.31 (m, IH), 3.22-2.98 (m, 3H), 2.42 (s, 3H), 2.02 (m, 2H), 1.61- 1.55 (m, 6H), 1.50-1.45 (m, 13H). 13 C NMR (CDC1 3 ): δ = 177.3, 170.7, 169.8, 150.6, 144.3, 133.1, 130.1, 129.9, 127.9, 121.6, 110.8, 82.5, 62.2, 57.2, 53.7, 49.5, 44.9, 37.2, 29.7, 27.8, 25.7, 24.1, 21.4. Example 81 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI-L-4- (1 , l-dioxothiomorpholin-4-ylcar bony loxy )pheny lalanine tert-Butyl Ester The product of Example 82 was oxidized by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525), yielding the title compound as a white solid. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.69 (d, 2H), 7.33-7.29 (m, 3H), 7.20 (d, 2H), 7.00 (d, 2H), 4.71-4.66 (m, IH), 4.13-4.04 (m, 5H), 3.37-3.32 (m, IH), 3.21-3.00 (m, 7H), 2.41 (s, 3H), 2.05-2.01 (m, IH), 1.52-1.44 (m, 12H). 13 C NMR (CDC1 3 ): δ = 170.7, 169.7, 149.8, 144.3, 134.4, 133.3, 130,6, 130.0, 127.9, 121.4, 82.7, 62.4, 54.0, 52.1, 49.7, 43.2, 37.6, 29.7, 28.1, 24.4, 21.7. Example 82 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (thiomorpholin-4-ylcarbonyloxy)phenylalanine tert-Butyl Ester Substimting thiomoφholine for N-methylpiperazine, and following the methods for the preparation of Example 4, gave the title compound as a white solid. ΝMR data was as follows: 13 C ΝMR (CDCI 3 ): δ = 7.70 (d, 2H), 7.31-7.26 (m, 2H), 7.16 (d, 2H), 7.00 (d, 2H), 4.72-4.66 (m, IH), 4.07-4.04 (m, IH), 3.89-3.79 (m, 4H), 3.37-3.32 (m, IH), 3.22-2.99 (m, 3H), 2.67 (t, 4H), 2.42 (s, 3H), 2.02 (m, 2H), 1.50-1.45 (m, 12H). 13 C NMR (CDC1 3 ): δ = 177.2, 170.7, 169.8, 153.5, 150.2, 144.3, 133.6, 132.9, 130.3, 129.9, 127.9, 121.5, 82.5, 62.4, 53.7, 49.5, 47.0, 46.4, 37.2, 29.6, 27.8, 27.3, 24.1, 21.4. Example 83 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (pyrrolidin-l-ylcarbonyloxy)phenylalanine tert-Butyl Ester Substimting pyrrolidinecarbonyl chloride for dimethylcarbamyl chloride, and following the methods for the preparation of Example 2, gave the title compound as a white solid. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.71 (d, 2H), 7.32 (d, 2H), 7.15 (d, 2H), 7.04 (d, 2H), 4.73-4.67 (m, IH), 4.07-4.04 (m, IH), 3.53 (t, 2H), 3.45 (t, 2H), 3.36-3.32 (m, IH), 3.24-2.98 (m, 3H), 2.42 (s, 3H), 2.03-1.88 (m, 5H), 1.75 (s, IH), 1.52 (1.24 (m, 12H). 13 C NMR (CDC1 3 ): δ - 170.7, 169.8, 153.1, 150.4, 144.3, 133.1, 130.1, 129.9, 127.9, 121.6, 110.8, 99.8, 82.5, 62.2, 53.7, 49.5, 46.3, 37.2, 29.7, 27.8, 25.6, 24.8, 24.0, 21.4. Example 84 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-thiaprolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedures described for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.87 (m, 2H), 7.28-7.13 (m, 5H), 7.02 (d, 2H), 4.70-4.60 (m, 2H), 4.58 (d, IH), 4.06 (d, IH), 3.38-3.01 (m, 3H), 3.09 (s, 3H), 3.00 (s, 3H), 2.58 (m, IH), 1.47 (s, 9H). 13 C NMR (CDC1 3 ): δ = 169.7, 167.8, 154.9, 150.7, 132.7, 130.9, 130.7, 130.4, 121.8, 117.1, 116.8, 82.9, 65.1, 53.9, 51.4, 36.8, 36.6, 36.4, 33.1, 27.9. Example 85 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(l,l-dioxo)thiaprolyI- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared from the product of Example 84 following the procedure oxidation procedure of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.90 (m, 2H), 7.30-7.04 (m, 7H), 4.83-4.58 (m, 3H), 3.66 (m, 2H), 3.32-3.24 (m, IH), 3.09-2.85 (m,2H), 3.10 (s, 3H), 3.01 (s, 3H), 1.50 (s, 9H). 13 C NMR (CDC1 3 ): δ = 173.1, 169.8, 168.0, 165.6,154.9, 150.9, 132.6, 131.1, 131.0, 130.3, 122.3, 117.3, 117.0, 83.2, 62.8, 57.8, 53.9, 49.0, 36.8, 36.6, 36.4, 27.9. Example 86 Synthesis of N-(2,5-Dichlorothiophene-3-sulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.14 (d, 2H), 7.09 (s, IH), 7.07 (d, IH), 7.01 (d, 2H), 4.73-4.66 (m, IH), 4.32-4.28 (m, IH), 3.42-3.17 (m, 3H), 3.08 (s, 3H), 3.06-3.01 (m, IH), 2.98 (s, 3H), 2.17-2.04 (m, IH), 1.84-1.60 (m, 2H), 1.60-1.46 (m, IH), 1.45 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.2, 169.9, 154.9, 150.6, 133.4, 133.1, 131.2, 130.2, 127.9, 127.0, 121.7, 82.7, 62.2, 53.6, 49.3, 37.2, 36.6, 36.4, 30.1, 27.8, 24.2. Example 87 Synthesis of N-(4-Acetamidobenzenesulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDCI 3 ): δ = 8.58 (s, IH), 7.70-7.67 (m, 4H), 7.32 (d, IH), 7.14 (d, 2H), 7.01 (d, 2H), 4.68 (m, IH), 3.99 (m, IH), 3.37-3.34 (m, IH), 3.23-3.16 (m, IH), 3.11-3.01 (m, IH), 3.08 (s, 3H), 2.98 (s, 3H), 2.13 (s, 3H), 1.97-1.94 (m, IH), 1.55-1.47 (m, 3H), 1.44 (s, 9H). 13 C NMR (CDCI 3 ): δ = 171.1, 169.9, 169.4, 155.0, 150.6, 143.3, 133.3, 130.2, 130.0, 128.9, 121.7, 119.4, 82.7, 62.2, 53.8, 49.6, 37.2, 36.6, 36.4, 29.9, 27.8, 24.4, 24.1. Example 88 Synthesis of N-(4-tert-Butylbenzenesulfonyl)-L-(l , 1-dioxothiaιnorpholin- 3-carbonyl)-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 73 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.81 (d, 2H), 7.59 (d, 2H), 7.07 (d, 2H), 6.97 (d, 2H), 6.46 (d, IH), 4.95 (m, IH), 4.62 (m, IH), 4.06 (m, 2H), 3.23 (m, IH), 3.07 (m, 4H), 2.97 (m, 4H), 2.81 (m, 4H), 1.55 (s, 9H), 1.37 (s, 9H). 13 C NMR (CDC1 3 ): δ = 170.0, 164.9, 158.2, 154.8, 150.6, 135.0, 132.6, 130.2, 127.4, 126.9, 122.2, 82.7, 56.1, 53.5, 49.7, 48.8, 41.5, 36.5, 36.3, 36.1, 35.2, 30.8, 27.8. Example 89 Synthesis of N-(Pyridine-3-sulf onyl)-L-prolyI- L-4-(V,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 56 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 8.95 (s, IH), 8.83 (d, IH), 8.28-8.24 (m, IH), 7.73-7.69 (m, IH), 7.30 (d, 2H), 7.05 (d, 2H), 4.68-4.63 (m, IH), 4.29- 4.25 (m, IH), 3.47-3.41 (m, IH), 3.38-3.22 (m, 2H), 3.09 (s, 3H), 3.06- 3.02 (m, IH), 2.96 (s, 3H), 1.92-1.66 (m, 4H). 13 C NMR (CD 3 OD): δ = 174.2, 173.9, 160.6, 160.0, 156.9, 152.9, 152.0, 147.9, 139.1, 136.9, 135.7, 131.6, 126.5, 123.1, 63.1, 54.8, 50.4, 37.5, 36.8, 36.7, 32.2, 25.5. Example 90 Synthesis of N-(2-Fluorobenzenesulfonyl)-L-(l , 1-dioxothian orpholin- 3-carbonyl)-L-4-(iV,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester L-Thiamoφholine-3 -carboxylic acid was prepared by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). N-(2- fluorobenzene-4-sulfonyl)-L-thiamoφholine-3-carboxylic acid was prepared using the procedure described in Method 1. The title compound was prepared according to the procedures set forth above using suitable starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.92 (m, IH), 7.69 (m, IH), 7.34 (m, 2H), 7.16 (m, 2H), 6.99 (m, 2H), 6.60 (d, IH), 5.01 (m, IH), 4.64 (m, IH), 4.03 (m, 2H), 3.29 (m, IH), 3.06 (m, 6H), 2.90 (m, 7H), 1.49 (d, 9H). 13 C NMR (CDC1 3 ): δ = 169.9, 164.8, 160.3, 156.9, 154.9, 150.7, 136.6, 136.4, 132.7, 131.0, 130.3, 128.8, 126.4, 126.2, 125.1, 122.2, 118.1 , 117.8, 82.7, 56.3, 56.7, 50.2, 49.5, 41.8, 36.5, 36.3, 27.8. Example 91 Synthesis of N-(3-Fluorobenzenesulfonyl)-L-(l , 1-dioxothiamorpholin- 3-carbonyl)-L-4-(V,iV-dimethylcarbamyloxy)phenyIalanine tert-Butyl Ester L-Thiamoφholine-5-carboxylic acid was prepared by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). N-(3- fluorobenzene-4-sulfonyl)-L-thiamoφholine-5-carboxylic acid was prepared using the procedure described in Method 1. The title compound was prepared according to the procedures set forth above using suitable starting materials. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.66 (m, IH), 7.58 (m, 2H), 7.34 (m, IH), 7.07 (d, IH), 6.92 (d, IH), 6.42 (d, IH), 5.00 (m, IH), 4.58 (m, IH), 4.02 (m, 2H), 3.22 (m, IH), 3.05 (s, 3H), 2.98 (m, 6H), 1.45 (s, 9H). 13 C ΝMR (CDCI 3 ): δ = 170.0, 164.5, 164.4, 161.0, 154.9, 150.6, 140.3, 140.2, 132.5, 131.9, 131.8, 130.2, 123.2, 123.1, 122.2, 121.4, 121.2, 115.0, 114.7, 82.9, 56.1, 53.4, 49.9, 49.1, 41.7, 36.5, 36.3, 36.0, 27.8. Example 92 Synthesis of N-(2,4-Difluorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin- 3-carbonyl)-L-4-(N,N-dimethylcarbamyloxy)phenylaIanine tert-Butyl Ester L-Thiamoφholine-5-carboxylic acid was prepared by the method of Larsson and Carlson (Acta Chemica Scan. 1994, 48, 517-525). N-(2,4- difluorobenzene-4-sulfonyl)-L-thiamoφholine-5-carboxylic acid was prepared using the procedure described in Method 1. The title compound was prepared according to the procedures set forth above using suitable starting materials. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.93 (m, IH), 7.15 (m, 2H), 7.04 (m, 4H), 6.53 (d, IH), 4.97 (m, IH), 4.64 (m, IH), 4.05 (m, 2H), 3.21 (m, 3H), 3.17 (s, 3H), 2.97 (m, 5H), 1.43 (s, 9H). 13 C ΝMR (CDC1 3 ): δ = 170.0, 164.6, 154.9, 150.7, 132.6, 132.6, 130.3, 122.6, 122.1, 112.6, 112.3, 107.0, 106.7, 106.3, 82.8, 56.3, 53.5, 50.5, 49.8, 42.0, 36.5, 36.3, 27.8. Example 93 Synthesis of N-(4-Acetamidobenzenesulfonyl)-L-prolyl- L-4-(iV,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 87 using the procedure described in Method 11. ΝMR data was as follows: Η ΝMR (CD 3 OD): δ = 8.05 (d, IH), 7.78 (m, 4H), 7.26 (d, 2H), 7.02 (d, 2H), 4.94 (m, IH), 4.72-4.67 (m, IH), 4.13-4.09 (m, IH), 3.40-3.36 (m, IH), 3.30-3.05 (m, 3H), 3.08 (s, 3H), 2.97 (s, 3H), 2.15 (s, 3H), 1.81- 1.51 (m, 4H). 13 C ΝMR (CD 3 OD): δ = 174.3, 174.2, 172.3, 156.9, 152.0, 144.9, 135.5, 132.4, 131.6, 130.2, 122.9, 120.7, 63.2, 54.7, 50.6, 37.5, 36.8, 36.7, 31.7, 25.4, 24.0 Example 94 Synthesis of N-(4-Trifluoromethoxybenzenesulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 72 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 7.93 (d, 2H), 7.48 (d, 2H), 7.28 (d, 2H), 7.03 (d, 2H), 4.72-4.68 (m, IH), 4.17-4.13 (m, IH), 3.45-3.42 (m, IH), 3.28- 3.11 (m, 2H), 3.14-3.07 (m, IH), 3.09 (s, 3H), 2.97 (s, 3H), 1.85-1.69 (m, 3H), 1.59 (m, IH). 13 C NMR (CD 3 OD): δ = 174.2, 174.1, 157.0, 153.9, 152.0, 137.3, 135.6, 131.7, 131.5, 123.0, 122.5, 121.8, 63.1, 54.7, 50.6, 37.4, 36.8, 36.6, 31.9, 25.4. Example 95 Synthesis of N-(4-FIuorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described in Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.90 (m, 2H), 7.22 (m, 4H), 7.00 (m, 3H), 5.08 (m, IH), 4.84 (m, IH), 4.56 (d, IH), 4.42 (d, IH), 3.88 (s, IH), 3.15-2.99 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.26-1.16 (m, 12H). 13 C NMR (CDC1 3 ): δ = 170.4, 168.2, 167.5, 164.1, 154.9,150.7, 132.8, 132.2, 132.1, 131.0, 130.8, 130.3, 121.8, 116.9, 116.6, 73.5, 69.6, 54.6, 53.2, 50.5, 37.6, 36.6, 36.3, 29.1, 23.8, 21.6, 21.5. Example 96 Synthesis of N-(4-Cyanobenzenesulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 58 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ = 8.14 (d, IH), 7.94-7.89 (m, 4H), 7.29 (d, 2H), 7.03 (d, 2H), 4.70-4.66 (m, IH), 4.21-4.17 (m, IH), 3.47-3.40 (m, IH), 3.31-3.21 (m, 2H), 3.11-3.04 (m, IH), 3.09 (s, 3H), 2.97 (s, 3H), 1.87- 1.72 (m, 3H), 1.70-1.61 (m, IH). 13 C NMR (CD 3 OD): δ = 174.2, 173.9, 157.0, 152.0, 142.9, 135.7, 134.5, 131.7, 129.7, 123.0, 118.6, 111.8, 63.0, 54.7, 50.5, 37.4, 36.8, 36.7, 32.0, 25.4. Example 97 Synthesis of N-(Toluene-4-sulfonyl)-L-(3,3-dimethyl)prolyl- L-4-(iV,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described for the preparation of Example 98. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.76 (d, IH), 7.75 (d, IH), 7.35 (d, IH), 7.34 (d, IH), 7.33 (d, IH), 7.20 (d, IH), 7.10 (d, IH), 7.03 (d, IH), 6.91 (d, 0.5H), 6.08 (d, 0.5H), 4.86 (ddd, 0.5H), 4.77 (q, 0.5H), 3.61 -3.47 (m, 2H), 3.27-3.02 (m, 3H), 3.09 (s, 3H), 3.00 (s, 3H), 2.45 (s, 1.5H), 2.43 (s, 1.5H), 1.75-1.68 (m, 0.5H), 1.61-1.51 (m, 0.5H), 1.45 (s, 4.5H), 1.40 (s, 4.5H), 1.48-1.25 (m, 3H); 0.95 (s, 1.5H), 0.80 (s, 1.5H); 0.61 (s, 1.5H). 13 C NMR (CDCI 3 ): δ = 170.4, 170.1, 170.0, 169.6, 155.0, 154.9, 150.7, 150.6, 144.3, 144.2, 133.4, 133.1, 132.8, 132.6, 130.7, 130.2, 129.9, 129.8, 128.0, 121.8, 121.7, 82.6, 82.2, 71.5, 71.2, 53.6, 52.7, 47.3, 47.2, 42.7, 42.5, 38.2, 38.1, 37.7, 37.5, 36.6, 36.3, 27.8, 27.8, 27.2, 23.4, 23.2, 21.5. Example 98 Synthesis of N-(Toluene-4-sulfonyl)-L-(3,3-dimethyl)prolyl- L-4-(N,N-dimethylcarbamyloxy)phenyIalanine Isopropyl Ester 3,3-Dimethyl proline (see Sharma and Lubell, /. Org. Chem. 1996, 61, 202-209) was N-tosylated using the procedure described in Method 1. The title compound was then prepared following the procedure described for the preparation of Example 2. NMR data was as follows: Η NMR (CDC1 3 ): δ = 7.76 (d, IH), 7.74 (d, IH), 7.36 (d, IH), 7.33 (d, 2H), 7.19 (d, IH), 7.10 (d, IH), 7.03 (d, IH), 6.91 (d, 0.5H), 6.89 (d, 0.5H), 5.06 (sept. , 0.5H), 4.96 (sept., 0.5H), 4.98-4.83 (m, IH), 3.59-3.48 (m, 2H), 3.31-3.03 (m, 3H), 3.09 (s, 3H), 3.00 (s, 3H), 2.45 (s, 1.5H), 2.43 (s, 1.5H), 1.75-1.66 (m, 0.5), 1.62-1.52 (m, 0.5H), 1.34-1.22 (m, 3H), 1.27 (s, 1.5H), 1.25 (s, 1.5H), 1.22 (s, 1.5H), 1.20 (s, 1.5H), 0.95 (s, 1.5H), 0.78 (s, 1.5H), 0.60 (s, 1.5H), 0.57 (s, 1.5H). 13 C NMR (CDCI 3 ): δ = 170.8, 170.6, 170.0, 169.7, 154.9, 150.8, 150.6, 144.4, 144.2, 133.2, 132.5, 132.5, 130.7, 130.2, 129.9, 129.8, 128.0, 122.0, 121.8, 71.5, 17.2, 69.5, 69.3, 53.0, 52.2, 47.3, 47.2, 42.8, 42.5, 38.2, 38.1, 37.6, 37.2, 36.6, 36.3, 27.1, 23.4, 23.2, 21.6, 21.6, 21.5, 21.5. Other compounds prepared by the methods described above include those set forth in Examples 99-137 in Table II below. In addition, Examples 101, 109, 111, 117, 132 and 137 found in Table II are exemplified as follows: Example 101 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl- 4-(N,N-dimethylcarbamyloxy)-L-phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2. NMR data was as follows: Η NMR (CD 3 ) 2 SO: δ = 8.28 (d, IH), 7.70 (d, 2H), 7.41 (d, 2H), 7.23 (d, 2H), 6.99 (d, 2H), 4.86 (sept, IH), 4.47 (m, IH), 4.40 (m, IH), 4.10 (m, IH), 4.07 (m, IH), 3.38 (m, IH), 3.30 (m, IH), 3.09 (m, 3H), 2.95 (s, 3H), 3.00 (s, 3H), 2.88 (s, 3H), 2.39 (s, 3H), 1.63 (m, 3H), 1.51 (m, 3H), 1.44 (m, IH), 1.39 (m, IH), 1.16 (d, 3H), 1.11 (d, 3H). 13 C NMR (CD 3 ) 2 SO: δ = 171.3, 170.8, 154.2, 150.2, 143.7, 134.1, 130.2, 130, 127.6, 121.6, 68.2, 61.2, 53.5, 49, 36.3, 36.1, 35.7, 30.5, 23.8, 21.4, 21.4, 21. Example 109 Synthesis of N-(BenzylsulfonyI)-L-(5,5-dimethyl) thiaprolyl-L-(4-N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 111 using the procedure described in Method 11. Physical data was as follows: MS (FAB) (M+H) + 550. Calcd. for: C 25 H 31 N 3 O 7 S 2 ; C, 54.62; H, 5.68; N 7.64. Found: C 54.51; H 5.60; N 7.63. Example 111 Synthesis of N-(Benzylsulfonyl)-L-(5,5-dimethyl) thiaprolyl-L- (4-N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 2 and by substituting the appropriate starting materials. Physical data was as follows: MS [M+H] + 550. Calcd. for: C 29 H 39 N 3 O 7 S 2 ; C, 57.52; H, 6.45; N, 6.94. Found: C, 57.32; H, 6.52; N, 6.81. Example 117 Synthesis of N-(Methyl-pyrazole-4-sulfonyl)-L-prolyl- L-(4-N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester Substimting N-methyl-pyrazole sulfonyl chloride (see Dickson, US 3,665,009 (May 23, 1972) and following the method for the preparation of Example 56, gave the title compound. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.83 (s, IH), 7.76 (s, IH), 7.26 (m, IH), 7.15 (m, 2H), 7.00 (m, 2H), 4.69 (m, IH), 3.95 (m, IH), 3.93 (s, 3H), 3.38 (m, IH), 3.23-3.11 ( , IH), 3.10-2.99 (m, 4H), 2.99 (s, 3H), 2.05 (m, IH), 1.66-1.46 (m, 3H), 1.44 (s, 9H). 13 C ΝMR (CDC1 3 ): δ 170.7, 169.9, 154.9, 150.6, 138.9, 133.2, 132.5, 130.2, 121.7, 117.9, 82.6, 62.4, 53.7, 49.7, 39.6, 37.7, 36.6, 36.4, 29.9, 27.9, 24.2. Example 132 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-prolyl-L- 4-(l , l-dioxothiomorpholin-4-ylcarbonyloxy)- phenylalanine tert-Butyl Ester Substimting thiamoφholine for N-methylpiperazine, and following the method for the preparation of Example 4 and 14, gave the title compound. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ = 7.87-7.82 (m, 2H), 7.28-7.17 (m, 5H), 7.01 (d, 2H), 4.71-4.69 (m, IH), 4.14-4.05 (m, 5H), 3.39-3.36 (m, IH), 3.23-3.01 (m, 7H), 2.05-2.03 (m, IH), 1.58-1.44 (m, 12H). 13 C ΝMR (CDC1 3 ): δ = 170.4, 169.8, 153.0, 149.7, 134.2, 130.6, 130.5, 121.3, 116.8, 116.5, 82.6, 62.1, 53.6, 51.8, 49.5, 43.1, 42.7, 37.2, 29.7, 27.8, 24.2. Example 137 Synthesis of N-(Methyl-pyrazole-4-sulfonyl)- L-prolyl-L-(4-N,N-dimethylcarbamyloxy)- phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 117. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ 7.83 (s, IH), 7.76 (s, IH), 7.27 (d, IH), 7.13 (d, 2H), 7.01 (d, 2H), 5.06-5.02 (m, IH), 4.80-4.73 (m, IH), 3.97-3.94 (m, IH), 3.93 (s, 3H), 3.44-3.37 (m, IH), 3.25-3.19 (m, IH), 3.09-3.00 (m, 5H), 2.97 (s, 3H), 2.06-2.02 (m, IH), 1.66-1.48 (m, 3H), 1.23 (d, 6H). 13 C ΝMR (CDC1 3 ): δ 170.8, 170.5, 154.9, 150.6, 138.9, 132.9, 32.5, 130.2, 121.7, 117.8, 69.5, 62.3, 53.2, 49.7, 39.6, 37.1 , 36.6, 36.3, 29.9, 24.1, 21.6, 21.5. Table II R3 O R 5 O O II II R 1 -s- N-CH-C-N-CH- -cC-— R 6' II O I H R 2 t t t Additional compounds prepared by the methods described above include the following: Example 138 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyI)thiaprolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The N-methylpyrazole sulfonyl chloride was prepared by adding N- methylpyrazole to chilled (0°C) chlorosulfonic acid. The reaction mixture was allowed to warm to room temperamre and then heated to 100°C overnight under a stream of N 2 . The reaction mixmre was then cooled to room temperamre and chilled to 0°C. To this solution was added thionyl chloride (2.5 eq.) and the reaction was stirred at room temperamre for 30 min. , then warmed to 70 °C for two hours. The reaction was cooled to room temperamre and then chilled in an ice bath. Water and ice were slowly added to the reaction mixmre to precipitate a white solid which was collected by filtration. The desired sulfonyl chloride was washed with cold water and hexane. The title compound was then prepared following the procedure outlined for the preparation of Example 2 by substimtion of the appropriate starting materials, mp: 169-170 °C. Example 139 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5- dimethyl)thiaprolyl-L-4-(N,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 138 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDCI 3 ): 8 = 7.94 (s, IH); 7.79 (s, IH); 7.25 (d, 2H, J=8.8Hz); 7.0 (d, 2H, J=8.8Hz); 5.15 (br s, IH); 4.80 (m, IH); 4.54 (d, lH,J=9.HHz); 4.39 (d, IH, J=9.3Hz); 3.93 (s, 3H); 3.88 (s, IH); 3.23- 3.02 (m, 2H0; 3.07 (s, 3H); 2.98 (s, 3H); 1.27 (s, 3H); 1.14 (s, 3H). 13 C NMR (CDCI 3 ): 173.86, 169.05, 155.23, 150.47, 139.21, 133.59, 133.15, 130.53, 121.84, 117.57, 73,58, 54,71, 53.75, 50.42, 39.60, 37.18, 36.60, 36.36, 35.11, 28.97, 23.95. Example 140 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(N- (l,4-dioxa-8-aza-spiro[4.5]decan-8-yl)carbonyloxy)phenylalanine Ethyl Ester The title compound was prepared following the procedure outlined for Example 4 by substimtion of the appropriate starting materials. Physical data was as follows: MS (+ESI): 630 [M+H] + Anal. Calcd. for C 31 H 39 N 3 O 9 S • 0.2 CH 2 C1 2 : C, 57.94; H, 6.14; N, 6.50. Found: C, 57.73; H, 5.90; N, 6.47. Example 141 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l,4-dioxa-8-aza-spiro[4.5]decan- 8-yl)carbonyloxy)phenylalanine The product of Example 140 was hydrolyzed using the procedure described in Method 5 but employing methanol as the solvent and running the reaction at 25 °C for 24h. The solvent was then evaporated, the residue taken up in H 2 O, washed with methylene chloride and lyophilized to afford the title compound. Physical data was as follows: MS (+ESI): 619 [M+H] + . Anal. Calcd. for C 29 H 35 N 3 O 9 SLi • 1.5 H 2 0: C, 53.37; H, 6.02; N, 6.44. Found: C, 53.40; H, 5.58; N, 6.48. Example 142 Synthesis of N-(ToIuene-4-sulfonyl)-L-prolyl-L-4- (4 ' -acetylpiperazin- 1 -ylcarbonyloxy) phenylalanine The product of Example 127 was hydrolyzed using the procedure described in Method 5 but employing methanol as the solvent and running the reaction at 25 °C for 24h. The solvent was then evaporated, the residue taken up in H 2 O, washed with methylene chloride and lyophilized to afford the title compound. Physical data was as follows: MS (+ESI): 587 [M+H] + . Anal. Calcd. for C 28 H 33 N 4 O 8 SLi • 3H 2 0: C, 52.01; H, 6.08; N, 8.66. Found: C, 52.03; H, 5.36; N, 8.04. Example 143 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (4 ' -methanesulf onylpiperazin- 1 -ylcarbonyloxy) phenylalanine The product of Example 128 was hydrolyzed using the procedure described in Example 142. Physical data was as follows: MS (+ESI): 623 [M+H] + . Anal. Calcd. for C 27 H 33 N 4 O 9 S 2 Li • 2 H 2 0: C, 48.79; H, 5.61; N, 8.43. Found: C, 48.66; H, 5.14; N, 8.04. Example 144 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (4 ' -phenylpiperazin- 1 -ylcarbonyloxy) phenylalanine The ethyl ester of the title compound was prepared following the procedure outlined for Example 4 by substimtion of the appropriate starting materials. The ethyl ester was then hydrolyzed using the procedure described in Example 142. Physical data was as follows: MS (-ESI): 619 [M-H] ~ . Anal. Calcd. for C 32 H 36 N 4 O 7 SLi • 2H 2 O: C, 58.00; H, 5.93; N, 8.45. Found: C, 57.65; H, 5.49; N, 8.13. Example 145 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (piperazin-l-ylcarbonyloxy)phenylalanine tert-Butyl Ester The product of Example 125 (0.7 g, 1 mmol) was dissolved in methylene chloride (9 mL). The solution was cooled to 0°C and trifluoroacetic acid (1.0 mL) was added and the resulting clear solution was stirred for 4h. The reaction solution was then diluted with additional methylene chloride (50 mL), washed with samrated sodium bicarbonate solution (3 x 50 mL), dried (K 2 CO 3 ) and the solvent stripped off to give a white solid (0.465 g). Flash chromotography (9: 1 CH 2 Cl 2 :EtOH) of this material gave a clear oil which was washed several times with hexane to give a white solid (0.289g, 48%). Physical data was as follows: MS (+ESI): 601.7 [M + l] + . Anal. Calcd. for C 30 H 40 N 4 0 7 S • 0.25 CH 2 C1 2 : C, 58.42; H, 6.56; N, 9.01. Found: C, 58.79; H, 6.51; N, 8.74. Example 146 Synthesis of 2-(Saccharin-2-yl)propionyl-L-4-(4'-methylpiperazin-l- ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 46 using the procedure described in Method 11, mp = 117-122°C (with foaming). Physical data was as follows: Anal. Calcd. for C 25 H 28 N 4 O 8 S • 1.5 H 2 O: C, 52.53; H, 5.47; N, 9.80. Found: C, 52.26; H, 5.36; N, 9.23. Example 147 Synthesis of N-(Toluene-4-sulfonyI)-L-proIyl-L-4-(4'-methanesulfonyl piperazin-l-ylcarbonyloxy)phenyla!anine tert-Butyl Ester The title compound was prepared following the procedure outlined for Example 128 by substimtion of the appropriate starting materials. Physical data was as follows: MS (+ESI): 696 [M+NH + . Anal. Calcd. for C 31 H 42 N 4 O 9 S 2 • 0.5 CH 2 C1 2 : C, 51.62; H, 6.00; N, 7.76. Found: C, 51.55; H, 6.21; N, 7.60. Example 148 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (N,N-dimethyIcarbamyloxy)phenylalanine (N -tert- butoxycarbonyl-2-amino-2-methylpropyl) Ester (BOC) 2 O (96 mg, 0.44 mmol) was added to a solution of the product from Example 9 (200 mg, 0.4 mmol.), N-Boc-2-amino-2-methyl-l-propanol (965 mg, 0.5 mmol) and a catalytic amount of DMAP in THF (92 mL) containing pyridine (50 μl)- The mixmre was stirred at room temperamre under argon for 48 h. The mixmre was poured into IN HCl and extracted with ethyl acetate. The organic phase was washed (IN HCl), dried (MgS0 4 ) and the solvent was removed under reduced pressure. The residue was purified by flash chromatography (EtOAc: hexanes 2:1) to give the desired compound as an amoφhous white foam (150 mg., 55%). Physical data was as follows: MS: [M+H] + at 675. MS (+ESI) : [M+ NH + at 692 (100%). Example 149 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI-L-4- (N,N-dimethyIcarbamyloxy)phenylalanine 2-(Morpholin-4-yl)ethyl Ester The title compound was prepared following the procedure outlined for Example 148 by substituting 2-moφholinoethanol for N-Boc-2-amino-2- methy 1- 1 -propanol . Physical data was as follows: Anal. Calcd. for C 30 H 40 N 4 O g S • 0.5 H 2 O: C, 57.58; H, 6.60; N, 8.95. Found: C, 57.26; H, 6.29; N, 8.82. Example 150 Synthesis of N-(Toluene-4-sulfonyI)-L-prolyl-L-4- (4 -acetyIpiperazin-l-yIcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for Example 127 by substimtion of the appropriate starting materials. Physical data was as follows: MS (+ESI) : 660.4 [M+NHJ + . Anal. Calcd. for C 32 N 42 N 4 O g S • 0.15 CH 2 C1 2 : C, 58.91 ; H, 6.50; N, 8.55. Found: C, 58.64; H, 6.36; N, 8.40. Example 151 Synthesis of N-(Toluene-4-sulfonyl)-L-proIyl-L-4- (4 -hydroxypiperidin-l-yIcarbonyIoxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for Example 4 by substituting 4-piperidinol for N-methyl piperazine. Physical data was as follows: Anal. Calcd. for C 31 H 41 Ν 3 O 8 S • 0.6 H 2 O • 0.22 EtOAc: C, 59.28; H, 6.86; N, 6.51 Found: C, 58.92; H, 6.37; N, 6.47. Example 152 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (N-(2 -(morpholin-4'-yl)ethyl)carbamyIoxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for Example 4 by substituting 4-(2-aminoethyl)moφholine for N-methyl piperazine. Physical data was as follows: Anal. Calcd. for C^H^ S • 0.25 H 2 O: C,59.20; H, 6.91; N, 8.63 Found: C, 59.01; H, 6.54; N, 8.38. Example 153 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l,4-dioxa-8-aza-spiro[4.5]decan- 8-yl)carbonyloxy)phenyIalanine tert-Butyl Ester The title compound was prepared following the procedure outlined for Example 4 by substimtion of the appropriate starting materials. Physical data was as follows: MS (-ESI): 656 [M-H]X Anal. Calcd. for C 33 H 43 N 3 O 9 S • 0.1 CH 2 C1 2 : C, 59.67; H, 6.54; N, 6.31. Found: C, 59.83; H, 6.63; N, 6.66. Example 154 Synthesis of N-(Toluene-4-sulfonyI)-L-prolyI-L-4- (N-(2 -hydroxyethyl)-N-methylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared folllowing the procedure outlined for Example 4 by substituting 2-(methylamino)ethanol for N-methyl piperazine. Physical data was as follows: Anal. Calcd. for C 29 H 39 N 3 O 8 S • 0.5 H 2 O: C, 58.18; H, 6.73; N, 7.02. Found: C, 57.95; H, 6.5; N, 6.9. Example 155 Synthesis of N-(Toluene-4-suIfonyl)-L-prolyl-L-4- (4 -formyloxypiperidin-l-ylcarbonyloxy)phenyIalanine The title compound was prepared by treating the product of Example 151 with formic acid overnight with stirring. The title compound was obtained as a white foam (130 mg., 94%), following removal of excess formic acid. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHZ) δ 12.8 (s, IH); 8.23 (s, IH); 8.09 (d, IH); 7.69 (d, 2H), 7.4 (d, 2H); 7.23 (d, 2H), 7.02 (d, 2H); 5.00 (m, IH); 4.45 (m, IH); 4.10 (m,lH); 3.6-3.8 (br, 2H); 3.4 (br s, IH); 3.25 (m, 2H); 3.10 (m, 2H); 2.95 (m, IH); 2.35 (s, 3H); 1.95 (m, 2H); 1.56-1.75 (m, 5H); 1.4 (m, IH). IR O Br^m- 1 ) 3400, 2950, 1720, 1680, 1510, 1430, 1325, 1250, 1150, 1010, 650, 75, 540. MS ((+)ESI, m/z (%)) 605 (100 [M+NH,1 + ). Anal. Calcd. for C 28 H 33 N 3 O 9 S.0.66H 2 O: C, 56.09; H, 5.77; N, 7.01. Found: C, 56.14; H, 5.83; N, 6.78. Example 156 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (4'-hydroxypiperidin-l-ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for Example 4 by substimtion of the appropriate starting materials, mp. 64-67 °C (with foaming). Physical data was as follows: Anal. Calcd. for C 30 H 39 N 3 O 8 S • 0.75 H 2 O • 0.1 EtOAc : C, 58.51; H, 6.67; N, 6.73. Found: C, 58.55; H, 6.09; N, 6.78. Example 157 Synthesis of N- (Toluene-4-sulf onyI)-L-prolyl-L-4-(4 ' -(2-hy droxy ethyl) piperazin- 1 - ylcarbonyloxy)phenylalanine tert-Butyl Ester The carbonate was prepared by treatment of Tos-Pro-Tyr-t-butyl ester with 4-nitrophenyl chloroformate, followed by addition of N-(2-hydroxyl ethyOpiperazine (triethylamine, methylene chloride, chilled to 0°C, then stirred at room temperature overnight). The crude product was purified by flash chromatography (silica, 95:5 EtOAc:EtOH) to afford a white solid, mp. l58-160°C. (0.387 g, 58%). NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHZ) δ 8.15 (d, IH, J=7.90 Hz); 7.70(d, 2H, J=6.59 Hz); 7.40 (d, 2H, J=7.90 Hz); 7.23(d, 2H, J = 8.56 Hz); 7.00 (d, 2H, J=8.56 Hz); 4.42 (m, IH); 4.38 (m, IH); 4.08 (m, IH); 3.51 (m, 4H); 3.34 (m, 3H); 3.09 (m, IH); 2.99 (m, 2H); 2.43 (m, 6H); 2.39 (s, 3H); 1.59 (m, 3H); 1.39 (m, IH); 1.35 (s, 9H). IR (KB^cm- 1 ) 3505, 3400, 2990, 2930, 2890, 1730, 1700, 1670, 1510, 1430, 1350, 1220, 1200, 1160, 670, 590, 545. MS ((-)ESI, m/z (%)) 643 (98 [M-NHJ). Anal. Calcd. for 0 3 ^ 44 ^0^: C, 59.61; H, 6.88; N, 8.69. Found: C, 59.06; H, 6.95; N, 8.43. Example 158 Synthesis of N-(ToIuene-4-sulfonyl)-L-prolyI-L-4-(N-(2 - formyloxyethyl)-N-methylcarbamyloxy)phenylalanine The title compound was prepared by treating the product of Example 154 with formic acid overnight with stirring. The title compound was obtained as a white foam (110 mg. , 77%), following removal of excess formic acid. NMR data was as follows: Η NMR (DMSO-c ., 400 MHz) δ 12.8 (s, IH); 8.25 (d, IH); 8.08 (d, IH); 7.69 (d, 2H), 7.40 (d, 2H); 7.22 (d, 2H), 6.98 (dd, 2H); 4.47 (m, IH); 4.35 (m, IH); 4.27 (m, IH); 4.10 (m, IH); 3.65 (m, IH); 3.55 (m, IH); 2.85-3.15 (overlapping m, 7H); 2.40 (s, 3H); 1.55 (m, 3H); 1.40 (m, IH). IR (KB^cm- 1 ) 3420, 2910, 1725, 1510, 1400, 1340, 1270, 1150, 675, 590, 550. MS ((+)ESI, m/z (%)) 579 (100 [M+NH,1 + ). Anal. Calcd. for C 26 H 31 N 3 O 9 S.0.66H 2 O: C, 54.45; H, 5.68; N, 7.33 Found: C, 54.41; H, 5.60; N, 7.24. Example 159 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2'-hydroxyethyl)-N- methylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for Example 4 by substimtion of the appropriate starting materials, mp. 49- 52°C. Physical data was as follows: Anal Calcd. for C 28 H 37 N 3 O 8 S • 0.5 H 2 O: C, 57.52; H, 6.55; N, 7.19. Found: C, 57.56; H, 6.38; N, 7.14. Example 160 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-4-(N- (methoxycarbonylmethyl)carbamyloxy)phenylalanine tert-Butyl Ester The carbonate was prepared by treatment of Tos-Pro-Tyr-t-butyl ester with 4-nitrophenyl chloroformate, followed by addition of glycine methyl ester (triethylamine, methylene chloride, chilled to 0°, then stirred at room temperamre overnight). The crude product was purified by flash chromatography (silica, 3:2 EtOAc:hexane) to afford a white foam (0.640 g, 35%). NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHz) δ 8.15 (d, IH, J=8.12 Hz); 8.12 (d, 2H, J=6.15 Hz); 7.73 (d, 2H, J=8.34 Hz); 7.40 (d, 2H, J=7.90 Hz); 7.24 (d, 2H, J = 8.56 Hz); 6.98 (d, 2H, J = 8.34 Hz); 4.25 (m, IH); 4.07 (m, IH); 3.83 (d, 2H, J=6.15 Hz); 3.64 (s, 3H); 3.32 (m, IH); 3.02 (m, 3H); 2.39 (s, 3H); 1.56 (m, 3H); 1.41 (m, IH); 1.35 (s, 9H). IR (KB^CM- 1 ) 3400, 2990, 1745, 1680, 1500, 1370, 1350, 1200, 1160, 670, 600. MS ((+)ESI, m/z (%)) 621 (100[M+NH 4 ] + ). Anal. Calcd. for C 29 H 37 N 3 O 9 S: c, 57.70; H, 6.18; N, 6.96. Found: C, 57.63; H, 6.11; N, 6.74. Example 161 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl) thiaprolyI-L-4-(N,N-dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for Example 138 by substimtion of the appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.91 (s, IH), 7.81 (s, IH), 7.21 (d, 2H, J=8.2 Hz), 7.03 (m, 3H); 5.03 (m, IH), 4.84 (m, IH), 4.55 (d, IH), 4.42 (d, IH), 3.96 (s, 3H), 3.83 (s, IH), 3.18-3.01 (m, 2H), 3.10 (s, 3H), 3.01 (s, 3H), 1.28 (s, 3H), 1.24 (m, 6H), 1.17 (s, 3H). 13 C NMR (CDC1 3 ): δ 170.43, 166.31, 154.92, 150.68, 132.91, 132.88, 130.34,121.78, 117.69, 73.76, 69.61, 54,79, 53.2, 50.52, 39.61, 37.62, 36.58, 36.35, 28.96, 24.02, 21.57, 21.49. Example 162 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (4 -methoxypiperidin-l-ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for Example 156 by substimtion of the appropriate starting materials. NMR data was as follows: Η NMR (DSMO-cL,, 400 MHz) δ 8.10 (d, IH); 7.72 (d, 2H); 7.41(d, 2H); 7.24 (d, 2H); 7.02 (d, 2H); 4.92 (m, IH); 4.45 (m, IH); 4.10 (m, IH); 3.8 (br s, IH); 3.65 (br s, IH); 3.40 (M, 2H); 3.25 (s, 3H); 2.95-3.15 (overlapping m, 5H); 2.40 (s, 3H); 1.85 (br, 2H); 1.4-1.6 (m, 6H); 1.18 (d, 3H); 1.12 (d, 3H). IR (KBr.cnv 1 ) 3400, 2950, 1720, 1520, 1425, 1340, 1210, 1160, 1100, 625, 590, 540. MS ((+) ESI, m/z (%)) 633 [M+NH] + ). Example 163 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4- (4'-methoxypiperidin-l-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 162 using the procedure described in Method 5. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz) δ 12.8 (s, IH); 8.10 (d, IH); 7.72 (d, 2H); 7.41 (d, 2H); 7.24 (d, 2H); 7.02 (d, 2H); 4.45 (m, IH); 4.10 (m, IH); 3.8 (br s, IH); 3.65 (br s, IH); 3.40 (m, 2H); 3.25 (s, 3H); 2.95-3.15 (overlapping m, 5H); 2.40 (s, 3H); 1.85 (br, 2H); 1.4-1.6 (m, 6H). IR (KBr, cm 1 ) 3400, 2950, 1720, 1520, 1425, 1340, 1210, 1160, 1100, 625, 590, 540. MS ((-)ESI, m/z (%)) 572 (100 [M-H] ). Anal. Calcd. for C 28 H 35 N 3 O 8 S 0.33EtOAc. lH 2 O: C, 56.73; H, 6.44; N, 6.77. Found: C, 56.96; H, 6.01; N, 6.76. Example 164 Synthesis of N-(Toluene-4-sulfonyl)-L-4-oxoproIyl-L-4-(N,N- dimethyIcarbamyloxy)phenylalanine tert-Butyl Ester Dichloromethane (7 mL) was cooled to -60 °C (chloroform/dry ice bath). Oxalyl chloride (0.15 mL) was added. The product from Example 165 (870 mg) and dry DMSO (0.26 mL) were dissolved in dichloromethane (8 mL) and added slowly to the above solution. The reaction was stirred at -60 °C for 30 minutes under dry conditions. Triethylamine (1.05 mL) was added. After 5 minutes, the dry ice bath was removed. The reaction was stirred at room temperamre for 1 hour. The solvent was evaporated in vacuo. Ethyl acetate (30 mL) was added to the residue. The mixmre was washed with citric acid solution (5 % , 2 x 30 mL) and saturated NaHCC^ solution (2 x 30 mL); and finally with brine. The solution was dried over MgSO 4 . The solvent was evaporated in vacuo, and the residue was flushed on a silica gel column to give 440 mg of the desired product, mp: 78-80°C. Example 165 Synthesis of N-(Toluene-4-suIfonyI)-L-frα«,s-4- hydroxyprolyl-L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester N-(Toluene-4-sulfonyl)-L-trø«s-4-hydroxyproly l-L-4- (hydroxy)pheny lalanine tert-butyl ester (1.60 g) and dimethylcarbamyl chloride (0.30 mL) were dissolved in DMF at 0°C in an ice bath. Potassium carbonate powder (2.03 g) was added to the solution. The ice bath was removed after 5 minutes. The reaction was stirred at room temperamre for 6 hours. The solid was filtered. Ethyl acetate (40 mL) was added to the solution. The solution was washed with citric acid solution (5 % , 40 mL) 2 times, and saturated NaHCO 3 solution (40 mL) 1 time. The solution was then washed with brine and dried with MgSO 4 . The solvent was evaporated in vacuo to give 1.07 g of the title compound, mp: 170-172°C. Example 166 Synthesis of N-(3-FluorobenzenesuIfonyl)-L-prolyl-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester N-(3-Fluorobenzenesulfonyl)-L-prolyl-L-4- (hydroxy)phenylalanine tert-butyl ester (700 mg) and dimethylcarbamyl chloride (0.2 mL) were dissolved in DMF (15 mL) at 0°C in an ice bath. Potassium carbonate powder (1.375 g) was added to the solution. The ice bath was removed after 5 minutes. The reaction was stirred at room temperamre for 6 hours. The solid was filtered. Ethyl acetate (20 mL) was added to the solution. The solution was washed with citric acid solution (5%, 30 mL, 2x), and samrated NaHCO 3 solution. The solution was then washed with brine and dried with MgSO 4 . The solvent was evaporated in vacuo to give 890 mg of the title compound, mp: 107-109 °C. Example 167 Synthesis of V-(Morpholino-sulfonyl)-L-prolyl-L-(4- V,7V- dimethylcarbamyloxy)phenylaIanine tert-Butyl Ester N-(Moφholino-sulfonyl)-L-proline was prepared using the procedure described by Cheeseright, et al., J. Chem. Soc. Perkin Trans. 1 1994, 12, 1595 - 1600. The title compound was prepared following the procedure described for the preparation of Example 2. ΝMR data was as follows: Η ΝMR (CDClj): δ 7.13 (d, 2H), 7.03 (d, 2H), 6.92 (d, IH), 4.71 (q, IH), 4.25 (t, IH), 3.67 (t, 4H), 3.39 (dt, IH), 3.28 - 3.19 (m, IH), 3.23 (t, 4H), 3.18 (dd, IH), 3.08 (dd, IH), 3.09 (s, 3H), 3.00 (s, 3H), 2.16 - 2.08 (m, 2H), 1.98 - 1.86 (m, IH), 1.78 - 1.66 (m, IH), 1.45 (s, 9H). 13 C ΝMR (CDCI 3 ): δ 171.2, 170.4, 154.8, 150.7, 132.9, 130.3, 121.7, 82.7, 66.3, 62.6, 53.3, 49.6, 46.2, 37.0, 36.6, 36.3, 30.5, 27.8, 24.7. Example 168 Synthesis of N-(Morpholino-sulfonyl)-L-prolyl-L-(4-7VJV- dimethylcarbamyloxy)phenylaIanine The title compound was prepared from the product of Example 167 using the procedure described in Method 11. ΝMR data was as follows: Η NMR (CD 3 OD): δ 8.04 (d, IH), 7.25 (d, 2H), 7.01 (d, 2H), 4.71 - 4.64 (m, IH), 4.22 (dd, IH), 3.62 -3.50 (m, 4H), 3.43 - 3.31 (m, 2H), 3.24 (dd, IH), 3.11 (t, 4H), 3.09 (s, 3H), 3.03 (dd, IH), 2.97 (s, 3H), 2.22 - 2.11 (m, IH), 1.98 - 1.80 (m, 3H). !3 C NMR (CD 3 OD): δ 174.65, 174.58, 174.00, 156.60, 151.70, 135.30, 131.20, 122.70, 67.10, 63.10, 54.59, 54.50, 50.6, 47.10, 37.10, 36.50, 36.40, 32.0, 25.60. Example 169 Synthesis of V-(l-Methylpyrazole-4-sulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedures described for the preparation of Examples 14 and 117. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.93 (s, IH), 7.80 (s, IH), 7.12 (d, 2H), 6.98 (d, 2H), 6.44 (d, 1H0HH), 4.95 (m, IH), 4.66 (m, IH), 4.04 (m, 2H), 3.98 (s, 3H), 3.19 (m, 2H), 3.06 (m, 6H), 2.98 (m, 4H), 1.42 (m, 9H). 13 C NMR (CDCI 3 ): δ 170.58, 164.75, 154.91, 150.75, 139.33, 132.73, 132.43, 130.43, 122.18, 119.66, 83.07, 56.02, 53.23, 50.03, 49.03, 41.49, 39.63, 36.56, 36.31, 36.16, 27.87. Example 170 Synthesis of N-(2-FluorobenzenesuIfonyI)-L-(l,l-dioxothiamorphohn-3-carbonyl)-L- 4-( V,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 90 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 7.90 (m, IH), 7.72 (m, IH), 7.56 (d, IH), 7.37 (m, 2H), 7.20 (d, 2H), 7.07 (d, 2H), 5.18 (m, IH), 4.59 (m, IH), 4.26 (m, IH), 3.76 (m, 2H), 3.36 (m, IH), 3.21 (m, 2H), 3.08 (m, 6H), 2.96 (s, 3H). , C NMR (CD 3 OD): δ 173.85, 168.04, 162.06, 158.69, 156.92, 152.06, 137.69, 135.05, 131.83, 131.59, 129.77, 128.44, 128.26, 126.21, 123.17, 119.04, 118.75, 57.04, 54.99, 52.08, 51.66, 43.36, 37.24, 36.83, 36.66. Example 171 Synthesis of N-(2,4-Difluorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(iV,7V-dimethylcarbamyIoxy)phenylalanine The title compound was prepared from the product of Example 92 using the procedure described in Method 11. NMR data was as follows: ] H NMR (CD 3 OD): δ 8.88 (m, 1/2H), 8.14 (m, 1/2H), 7.90 (m, IH), 7.64 (m, IH), 7.20 (m, 2H), 7.10 (m, IH), 7.03 (m, 2H), 5.16 (m, IH), 4.63 (m, IH), 4.28 (m, IH), 3.75 (m, 2H), 3.41 (m, IH), 3.15 (m, 5H), 3.02 (m, 4H). 13 C NMR (CD 3 OD): δ 173.91, 168.04, 156.93, 152.05, 135.15, 133.81, 133.67, 131.60, 123.13, 113.48, 113.18, 107.38 ,107.02, 57.02, 55.02, 52.29, 51.84, 43.45, 37.34, 36.83, 36.66. Example 172 Synthesis of N-(Toluene-4-sulfonyl)-L-(thiamorpholin-3-carbonyl)-L-4-(N,N- dimethyIcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 49 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.67 (d, 2H), 7.32 (d, 2H), 7.21 (d, 2H), 7.10 (d, IH), 7.00 (d, 2H), 5.40 (bs, >1H), 4.85 (m, 2H), 3.95 (m, IH), 3.41 (m, IH), 3.07 (m, 6H), 2.98 (m, 4H), 2.62 (m, IH), 2.41 (m, 5H), 2.13 (m, IH). 13 C NMR (CDCI 3 ): δ 173.40, 168.49, 155.26, 144.44, 136.88, 132.95, 130.51, 130.30, 127.28, 122.08, 55.34, 53.45, 43.43, 36.62, 36.38, 35.85, 25.25, 24.54, 21.43. Example 173 Synthesis of V-(Pyridine-3-sulfonyl)-L-(5,5-dimethyl-thiaprolyI-L-4-(7V,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 56 by substitution of the appropriate starting materials. NMR data was as follows: •H NMR (CDCI 3 ): δ 9.13 (m, IH), 8.90 (m, IH), 8.19 (m, IH), 7.56 (m, IH), 7.23 (d, 2H), 7.04 (d, 2H), 6.93 (d, IH), 5.07 (m, IH), 4.85 (m, IH), 4.62 (d, IH), 4.48 (d, IH), 3.92 (s, IH), 3.20 - 3.05 (m, 2H), 3.12 (s, 3H), 3.03 (s, 3H), 1.32 - 1.16 (m, 12H). 13 C NMR (CDCI 3 ): δ 170.30, 167.75, 154.19, 150.67, 148.59, 135.72, 132.94, 132.72, 130.27, 123.91, 121.78, 73.62, 69.64, 54.69, 53.12, 50.48, 37.50, 36.53, 36.29, 29.05, 23.73, 21.54, 21.46. Example 174 Synthesis of N-(3-Fluorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)-L- 4-(7V,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 91 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 7.68 (m, 3H), 7.44 (m, IH), 7.20 (m, 2H), 7.01 (m, 2H), 5.21 (m, IH), 4.60 (m, IH), 4.20 (m, IH), 3.75 (m, IH), 3.43 (m, IH), 3.21 (m, 3H), 3.02 (m, 4H), 2.96 (m, 4H). 13 C NMR (CD 3 OD): δ 173.98, 167.98, 165.89, 162.56, 156.94, 152.06, 142.70 ,142.61, 135.11, 133.30, 133.19, 131.57, 124.71, 123.25, 122.21, 121.93, 116.05, 115.71, 57.27, 54.87, 54.79, 51.29, 51.06, 43.24, 37.11, 36.83. Example 175 Synthesis of N-(l-MethylpyrazoIe-4-suIfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N,7V-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 169 using the procedure described in Method 11. NMR data was as follows: Η NMR (CD 3 OD): δ 8.11 (s, IH), 7.83 (s, IH), 7.36 (d, IH), 7.24 (d, 2H), 7.02 (d, 2H), 5.16 (m, IH), 4.69 (m, IH), 4.19 (m, IH), 3.90 (s, 3H), 3.81 (m, 2H), 3.33 (m, 3H), 3.10 (s, 3H), 3.02 (m, 4H). 13 C NMR (CD 3 OD): δ 174.07, 168.11, 156.93, 152.08, 140.12, 135.05, 134.90, 131.67, 123.28, 121.82, 57.33, 54.77, 50.83, 50.64, 42.94, 39.80, 37.02, 36.84, 36.76. Example 176 Synthesis of N-(4-tert-Butylbenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-( V,7V-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 88 using the procedure described in Method 11. NMR data was as follows: »H NMR (CD 3 OD): δ 7.70 (d, 2H), 7.53 (d, 2H), 7.04 (d, 2H), 6.87 (d, 2H), 5.09 (m, IH), 4.48 (m, IH), 3.99 (m, IH), 3.60 (m, IH), 2.90 (m, 5H), 2.80 (m, 5H), 1.15 (s, 9H). 13 C NMR (CD 3 OD): δ 173.95, 168.09, 159.33, 156.88, 152.09, 137.52, 135.03, 131.54, 128.68, 128.15, 123.32, 57.27, 54.81, 50.75, 43.04, 36.97, 36.82, 36.65, 36.16, 31.35. Example 177 Synthesis of 7V-(Toluene-4-suIfonyl)-(3,3-dimethyl)prolyl-L-4-(7V,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 97 using the procedure described in Method 11. NMR data was as follows: •H NMR (CDC1 3 ): δ 7.77 (d, IH), 7.75 (d, IH), 7.42 - 7.33 (m, 3.5H), 7.27 (d, IH), 7.19 (d, 0.5H), 7.10 (d, IH), 7.03 (d, IH), 5.07 - 5.00 (m, 0.5H), 4.94 - 4.87 (m, 0.5), 3.67 (d, IH), 3.58 - 3.52 (m, IH), 3.35 - 3.25 (m, IH), 3.19 - 3.08 (m, 2H), 3.11 (s, 3H), 3.02 (s, 3H), 2.45 (s, 1.5 H), 2.43 (s, 1.5H), 1.70 - 1.57 (m, IH), 1.34 - 1.27 (m, IH), 0.94 (s, 1.5H), 0.75 (s, 1.5H), 0.54 (s, 6H). 13 C NMR (CDCI 3 ): δ 174.6, 174.4, 171.8, 171.4, 155.7, 150.5, 150.4, 144.5, 144.4, 133.5, 132.6, 130.9, 130.6, 130.0, 129.9, 128.0, 127.9, 122.2, 122.0, 71.2, 70.9, 53.3, 52.2, 47.3, 47.1, 43.0, 42.7, 38.1, 37.9, 36.6, 36.4, 27.0, 26.8, 23.3, 23.0. Example 178 Synthesis of iV-(2,5-Dichlorothiophene-3-sulfonyl)-L-prolyl-L-4-(7V.iV- dimethylcarbamyloxy)phenylaIanine The title compound was prepared from the product of Example 86 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 8.10 (d, IH), 7.25 (d, 2H), 7.20 (s, IH), 7.0 (d, 2H), 4.65 (m, IH), 4.35 (m, IH), 3.55 - 3.35 (m, 2H), 3.30 - 3.20 ( , 2H), 3.15 - 3.00 (m, 4H), 2.95 (s, 3H), 2.05 - 1.80 (m, 2H), 1.80- 1.65 (m, 2H). 13 C NMR (CD 3 OD): δ 174.2, 173.9, 156.9, 151.9, 135.9, 135.5, 132.3, 131.6, 128.9, 128.6, 122.9, 63.1, 54.8, 54.7, 50.3, 37.4, 36.8, 36.7, 32.1, 25.5. Example 179 Synthesis of N-(4-MethoxybenzenesuIfonyl)-L-proIyl-L-4-(iV,7V- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 180 using the procedure described in Method 7. NMR data was as follows: Η NMR (CD 3 OD): δ 7.78 (d, 2H), 7.27 (d, 2H), 7.09 (d, 2H), 7.02 (d, 2H), 4.71 - 4.67 (m, IH), 4.10 - 4.06 (m, IH), 3.88 (s, 3H), 3.41 - 3.31 (m, IH), 3.28 - 3.07 (m, 6H), 2.97 (s, 3H), 1.81 - 1.50 (m, 4H). 13 C NMR (CD 3 OD): δ 168.3, 168.2, 159.2, 150.9, 145.9, 129.5, 125.6, 125.3, 123.5, 1 16.9, 109.6, 57.2, 50.2, 48.7, 44.6, 31.4, 30.8, 30.6, 25.7, 19.3. Example 180 Synthesis of N-(4-MethoxybenzenesulfonyI)-L-prolyl-L-4-(7V,iV- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared using the procedure described in Example 2 by substitution of the appropriate starting materials. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.76 (d, 2H), 7.34 (d, IH), 7.14 (d, 2H), 7.03 - 6.97 (m, 4H), 5.08 - 5.04 (m, IH), 4.77 (m, IH), 4.05 - 4.03 ( , IH), 3.86 (s, 3H), 3.37 - 3.34 (m, IH), 3.26 - 3.19 (m, IH), 3.10 - 3.01 (m, 4H), 2.98 (s, 3H), 2.02 (m, IH), 1.56 - 1.46 (m, 3H), 1.25 (d, 6H). 13 C NMR (CDCI 3 ): δ 170.8, 170.3, 163.4, 154.8, 150.5, 132.9, 130.1, 129.9, 127.6, 121.6, 114.3, 69.4, 62.1, 55.4, 53.2, 49.5, 37.1, 36.5, 36.2, 29.7, 24.0, 21.5, 21.4. Example 181 Synthesis of V-(Toluene-4-sulfonyl)-L-(l-oxo-thiomorpholin-3-carbonyl)thiaprolyl-L- 4-( V,N-dimethyIcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 182 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 7.90 (m, IH), 7.78 (m, 2H), 7.40 (m, 2H), 7.26 (m, 2H), 7.03 (m, 2H), 5.14 (m, IH), 4.64 (m, 2H), 3.81 (m, IH), 3.71 (m, 2H), 3.19 (m, IH), 3.14 (m, 3H), 3.02 (m, 4H), 2.84 (m, IH), 2.60 (m, IH), 2.42 (m, 4H), 2.21 (m, IH). 13 C NMR (CD 3 OD): δ 174.22, 173.93, 169.59, 156.88, 152.08, 152.05, 146.44, 146.26, 137.75, 137.63, 135.61, 134.96, 131.79, 131.64, 131.55, 131.39, 128.75, 128.66, 123.35, 123.06, 57.03, 54.88, 54.66, 51.64, 42.69, 42.51, 40.34, 37.12, 36.83, 36.66, 32.76, 21.51. Example 182 Synthesis of N-(Toluene-4-sulfonyl)-L-(l-oxo-thiomorpholin-3-carbonyl)-L-4-(N,7V- dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 49. The oxidation of the thiomoφholine group to the 1-oxo-thiomoφholine group was per Larsson and Carlson (Acta Chemica Scan. 1994, 4 , 517-525). NMR data was as follows: •H NMR (CDCI 3 ): δ 7.72 (m, 2H), 7.69 (m, 2H), 7.31 (m, 2H), 7.11 (m, 2H), 7.07 (m, 2H), 6.96 (m, 2H), 4.79 (m, IH), 4.54 (m, IH), 3.80 (m, 4H), 3.04 (4H), 2.92 (m, 3H), 2.64 (m, IH), 2.43 (m, 4H), 1.44 (s, 3H), 1.36 (s, 6H). 13 C NMR (CDCI 3 ): δ 169.8, 166.5, 166.,3 154.6, 150.5, 150.4, 144.9, 144.4, 135.7, 135.3, 132.8, 130.5, 130.1, 29.9, 127.4, 126.9, 122.1, 121.4, 82.6, 82.2, 55.6, 53.9, 53.1, 50.6, 48.1, 47.8, 41.7, 40.5, 38.3, 36.4, 36.1, 31.1, 27.5, 21.2. Example 183 Synthesis of N-(3,4-Difluorobenzenesulfonyl)-L-prolyl-4-( V,N- dimethyIcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: •H NMR (CDC1 3 ): δ 7.72 - 7.60 (m, 2H), 7.87 - 7.37 (m, IH), 7.13 - 7.11 (m, 3H), 7.01 (d, 2H), 5.08 - 5.04 (m, IH), 4.81 - 4.74 (m, IH), 4.09 - 4.06 (m, IH), 3.39 - 3.35 (m, IH), 3.26 - 3.19 (m, IH), 3.12 - 2.97 (m, 8H), 2.06 - 2.03 (m, IH), 1.66 - 1.57 (m, 3H), 1.26 (d, 6H). 13 C NMR (CDCI 3 ): δ 170.50, 170.40, 154.90, 153.60, 150.70, 150.30, 133.30, 132.90, 130.10, 125.00, 121.80, 121.80, 118.50, 112.80, 69.60, 62.20, 53.20, 49.60, 37.10, 36.60, 36.30, 30.10, 24.20, 21.59, 21.56. Example 184 Synthesis of N-(3,4-Difluorobenzenesulfonyl)-L-prolyl-4-( V,7V- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 183 using the procedure described in Method 7. NMR data was as follows: Η NMR (CD 3 OD): δ 8.10 (d, IH), 7.84 - 7.77 (m, IH), 7.69 - 7.65 (m, IH), 7.53 - 7.45 (m, IH), 7.28 (d, 2H), 7.02 (d, 2H), 4.72 - 4.68 (m, IH), 4.19 - 4.16 (m, IH), 3.43 - 3.39 (m, IH), 3.31 - 3.21 (m, 2H), 3.13 - 3.05 (m, 4H), 2.97 (s, 3H), 1.86 - 1.61 (m, 4H). 13 C NMR (CD 3 OD): δ 174.2, 174.1, 164.7, 156.9, 154.9, 152.0, 151.6, 135.8, 135.6, 131.6, 129.7, 122.9, 119.7, 118.8, 63.1, 54.7, 50.5, 37.4, 36.8, 36.6, 31.9, 25.5. Example 185 Synthesis of 7V-(3,4-DifluorobenzenesulfonyI)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-( V,iV-dimethylcarbamyloxy)phenylaIanine tert-Butyl Ester The title compound was prepared using the procedure described in Example 92 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.71 (m, 2H), 7.33 (m, IH), 7.07 (d, 2H), 6.91 (d, 2H), 6.36 (d, IH), 4.95 (m, IH), 4.61 (m, IH), 4.03 (m, 2H), 3.16 (m, 2H), 3.13 (m, 4H), 3.07 (m, IH), 2.93 (s, 9H), 1.43 (s, 9H). 13 C NMR (CDC1 3 ): δ 170.07, 169.45, 164.42, 155.06, 155.44, 154.81, 152.21, 152.17, 150.58, 148.81, 148.64, 134.90, 134.85, 132.41, 130.29, 124.82, 124.71, 124.66, 121.97, 119.07, 118.76, 117.52, 117.23, 82.92, 55.98, 53.20, 50.10, 49.40, 41.76, 36.41, 36.16, 35.99, 27.64. Example 186 Synthesis of V-(3,4-Difluorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N, V-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 185 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 6.22 (m, IH), 6.03 (m, IH), 5.84 (m, IH), 5.58 (m, 2H), 5.38 (m, 2H), 3.33 (m, IH), 3.01 (m, IH), 2.57 (m, IH), 2.14 (m, IH), 1.91 (m, IH), 1.66 (m, 3H), 1.44 (s, 3H), 1.35 (m, 3H), 1.32 (s, 3H). 13 C NMR (CD 3 OD): δ 173.97, 167.89, 156.94, 153.53, 152.07, 150.00, 137.48, 135.17, 131.63, 126.54, 126.43, 123.20, 120.21, 119.96, 118.84, 118.57, 57.25, 54.82, 51.29, 49.86, 43.29, 37.21, 36.85, 36.67. Example 187 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(thiomorpholin-4- ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described in Example 82 by substitution of the appropriate starting materials. NMR data was as follows: 'H NMR (CDC1 3 ): δ 7.64 (d, 2H), 7.33 (d, 2H), 7.25 (d, 2H), 7.08 - 6.97 (m, 3H), 4.76 (m, IH), 4.57 (d, IH), 4.38 (d, IH), 3.83 (s, IH), 3.95 - 3.78 (m, 4H), 3.09 (m, 2H), 2.69 (m, 4H), 2.43 (s, 3H), 1.44 (s, 9H), 1.16 (s, 3H), 1.08 (s, 3H). 13 C NMR (CDCI 3 ): δ 169.78, 168.36, 153.53, 150.28, 144.84, 133.53, 132.76, 130.51, 130.03, 128.19, 121.58, 82.69, 73.42, 54.56,53.78, 50.46, 47.05, 46.40, 37.80, 29.06, 27.76, 27.37, 27.04, 23.86, 21.52. Example 188 Synthesis of V-(Toluene-4-sulfonyl)-L-(5,5-dimethyI)thiaproIyl-L-(thiomorpholin-4- ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Examples 187 using the procedures described in Method 11. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.77 (d, 2H), 7.37 (d, 2H), 7.28 (d, 2H), 7.22 (d, IH), 7.03 (d, 2H), 5.35 (brs, IH), 4.91 (m, IH), 4.60 (d, IH), 4.39 (d, IH), 3.91 (s, IH), 3.96 - 3.28 (m, 4H), 3.30 - 3.07 (m, 2H), 2.67 (m, 4H), 2.45 (s, 3H), 1.10 (s, 3H), 1.08 (s, 3H). 13 C NMR (CDCI 3 ): δ 173.09, 169.45, 153.81, 150.28, 145.02, 133.42, 132.61, 130.60, 130.12, 128.13, 121.86, 73.28, 54.51, 53.31, 50.48, 47.08, 46.47, 36.97, 28.97, 27.35, 27.03, 23.70, 21.52. Example 189 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaproIyl-L-4-(7V,N- dimethylcarbamyloxy)phenylalanine Ethyl Ester The title compound was prepared following the procedure described for the preparation of Example 117 by substitution of the appropriate starting materials. NMR data was as follows: •H NMR (CDCI 3 ): δ 7.89 (s, IH), 7.81 (s, IH), 7.19 (d, 2H), 7.00 (m, 3H), 4.87 (m, IH), 4.54 (d, IH), 4.42 (d, IH), 4.18 (q, 2H), 3.95 (s, 3H), 3.81 (s, IH), 3.11 (m, 2H), 3.08 (s, 3H), 2.99 (s, 3H), 1.30 (s, 3H), 1.25 (t, 3H), 1.16 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.98, 168.34, 154.91, 150.71, 139.62, 132.88, 130.28, 121.85, 117.71, 73.77, 61.66, 54.80, 53.16, 50.53, 39.64, 37.63, 36.60, 36.36, 28.98, 24.00, 13.92. Example 190 Synthesis of N-(Pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,iV- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 191 using the procedure described in Method 11. NMR data was as follows: Η NMR (CDCI 3 ): δ 9.09 (s, IH), 8.82 (m, IH), 8.20 (m, IH), 7.56 (m, IH), 7.23 (d, 2H), 7.07 (d, IH), 5.58 (brs, IH), 4.83 (m, lh), 4.56 (m, 2H), 4.07 (s, IH), 3.14 (m, 2H), 3.07 (s, 3H), 2.99 (s, 3H), 1.26 (s, 3H), 1.18 (s, 3H). 13 C NMR (CDCI 3 ): δ 173.04, 168.29, 155.16, 153.39, 150.60, 147.96, 136.43, 133.91, 133.06, 130.66, 130.50, 124.65, 122.14, 121.91, 73.43, 54.58, 53.21, 50.38, 37.18, 36.64, 36.38, 29.25, 23.64. Example 191 Synthesis of N-(Pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyI-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 56 and substimtion of appropriate starting materials. Physical data was as follows: MS: [M+H] + 593 Anal. Calcd. for C 27 H 36 N 4 O 7 S 2 • 0.5 H 2 0: C, 53.88; H, 6.07; N, 9.27. Found: C, 53.98; H, 6.07; N, 9.27. Example 192 Synthesis of N-(Pyridine-2-suIfonyl)-L-prolyl-L-4-(N,7V- dimethylcarbamyloxy)phenyIalanine Isopropyl Ester Substituting 2-pyridinesulfonyl chloride (see Corey, et al. J. Org. Chem. 1989, 54, 389-393) and following the method for the preparation of Example 56, gave the title compound. NMR data was as follows: •H NMR (CDC1 3 ): δ 8.59 (d, IH), 8.00 - 7.89 (m, 2H), 7.78 (d, IH), 7.53 - 7.49 (m, IH), 7.16 (d, 2H), 7.01 (d, 2H), 5.05 - 4.99 (m, IH), 4.85 - 4.78 (m, IH), 4.60 - 4.57 (m, IH), 3.44 -3.35 (m, 2H), 3.25 - 3.19 (m, IH), 3.07 (s, 3H), 3.06 - 3.01 (m, IH), 2.97 (s, 3H), 2.19 - 2.13 (m, IH), 1.88 - 1.71 (m, 2H), 1.55 (m, IH), 1.22 - 1.19 (m, 6H). 13 C NMR (CDCI 3 ): δ 170.90, 170.30, 156.20, 154.80, 150.50, 150.00, 138.00, 133.10, 130.10, 127.00, 123.40, 121.60, 69.20, 62.80, 53.30, 49.60, 37.20, 36.40, 36.20, 29.80, 24.30, 21.42, 21.40. Example 193 Synthesis of V-(Pyridine-2-sulfonyl)-L-prolyl-L-4-(N,7V- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 192 using the procedure described in Method 7. NMR data was as follows: Η NMR (CD 3 OD): δ 8.67 (d, IH), 8.27 (d, IH), 8.07 - 8.02 (m, IH), 7.96 - 7.91 (m, IH), 7.65 - 7.61 (m, IH), 7.27 (d, 2H), 7.01 (d, 2H), 4.72 - 4.69 (m, IH), 4.58 - 4.54 (m, IH), 3.44 - 3.37 (m, 2H), 3.28 - 3.24 (m, IH), 3.13 - 3.05 (m, 4H), 2.96 (s, 3H), 1.94 - 1.89 (m, 2H), 1.70 - 1.63 (m, 2H). 13 C NMR (CD 3 OD): δ 174.5, 174.4, 174.2, 157.7, 156.9, 151.9, 139.9, 135.6, 131.6, 128.8, 124.7, 122.9, 64.1, 54.8, 54.7, 50.9, 37.5, 36.8, 36.7, 31.9, 25.6. Example 194 Synthesis of N-(Pyridine-2-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 192 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDCI 3 ): δ 8.64 - 8.62 (m, IH), 7.98 - 7.92 (m, 2H), 7.56 - 7.51 (m, IH), 7.28 - 7.21 (m, 3H), 7.01 (d, 2H), 5.01 - 4.97 (m, IH), 4.88 - 4.85 (m, 2H), 4.80 (d, IH), 4.63 (d, IH), 4.19 (s, IH), 3.11 - 3.07 (m, 5H), 2.98 (s, 3H), 1.28 (s, 3H), 1.26 - 1.18 (m, 9H). 13 C NMR (CDCI 3 ): δ 170.3, 168.4, 155.5, 154.9, 150.7, 150.4, 138.2, 133.0, 130.4, 127.5, 123.5, 121.8, 73.5, 69.5, 54.7, 53.3, 51.0, 37.6, 36.6, 36.4, 29.3, 23.9, 21.52, 21.50. Example 195 Synthesis of V-(Pyridine-2-suIfonyI)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 194 using the procedure described in Method 7. NMR data was as follows: •H NMR (CD 3 OD): δ 8.70 - 8.69 (m, IH), 8.07 - 8.01 (m, IH), 7.92 - 7.89 (m, IH), 7.67 - 7.63 (m, IH), 4.77 - 4.67 (m, 3H), 4.30 (s, IH), 3.23 - 3.06 (m, 5H), 2.97 (s, 3H), 1.27 - 1.18 (m, 6H). ,3 C NMR (CD 3 OD): δ 174.1, 171.2, 157.0, 151.9, 151.6, 139.9, 135.7, 131.8, 131.7, 129.0, 124.6, 122.9, 74.3, 61.6, 55.7, 54.9, 51.9, 37.6, 36.8, 36.7, 30.1, 24.9. Example 196 Synthesis of 7V-(Toluene-4-sulfonyl)-L-(thiamorpholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)ρhenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 49 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.67 (d, 2H), 7.30 (d, 2H), 7.12 (d, 2H), 6.97 (d, 2H), 6.86 (d, IH), 5.05 (m, IH), 4.70 (m, 2H), 3.90 (m, IH), 3.31 (m, IH), 3.06 (m, 4H), 2.97 (s, 3H), 2.68 (m, IH), 2.50 (m, IH), 2.44 (s, 3H), 2.29 (m, IH), 2.13 (m, IH), 1.24 (s, 3H), 1.22 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.35, 167.55, 155.00, 150.61, 144.20, 136.80, 132.51, 130.24, 130.14, 127.20, 121.82, 69.48, 55.14, 53.55, 43.26, 36.43, 36.16, 25.21, 24.56, 21.48, 21.31. Example 197 Synthesis of 7V-(3-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyI-L-4-(N,N- dimethylcarbamyloxy)phenylaIanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.68 (d, IH), 7.61 - 7.52 (m, 2H), 7.36 (dt, IH), 7.21 (d, 2H), 7.02 (d, 2H), 6.94 (d, IH), 5.05 (sept, IH), 4.85 (q, IH), 4.59 (d, IH), 4.41 (d, IH), 3.88 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.16 (s, 3H), 1.12 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 168.1, 162.6, 154.9,150.7, 137.9, 132.8, 131.3, 130.4, 123.9, 121.8, 121.0, 115.4, 73.5, 69.6, 54.5, 53.2, 50.5, 37.6, 36.6, 36.3, 29.0, 23.7, 21.6, 21.5. Example 198 Synthesis of V-(2-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.92 - 7.87 (m, IH), 7.67 - 7.59 (m, IH), 7.33 - 7.24 (m, 2H), 7.21 (d, 2H), 7.03 (d, 2H), 6.93 (d, IH), 5.03 (Sept, IH), 4.83 (q, IH), 4.67 (d, IH), 4.63 (d, IH), 4.03 (s, IH), 3.16 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.31 (s, 3H), 1.24 (d, 3H), 1.22 (d, 3H), 1.19 (s, 3H). 13 C NMR (CDC1 3 ): δ 170.3, 168.1, 159.2, 154.9, 150.7, 136.0, 132.9, 132.0, 130.3, 124.6, 121.8, 117.6, 73.3, 69.6, 54.8, 53.2, 50.3, 37.6, 36.6, 36.3, 29.1, 23.9, 21.6, 21.5. Example 199 Synthesis of N-(3,4-Difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(iV,7V- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.77 - 7.71 (m, IH), 7.70 - 7.65 (m, IH), 7.40 - 7.31 (m, IH), 7.20 (d, 2H), 7.02 (d, 2H), 6.87 (d, IH), 5.05 (Sept, IH), 4.88 - 4.82 (m, IH), 4.55 (d, IH), 4.44 (d, IH), 3.91 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.23 (s, 3H), 1.18 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.4, 167.9, 154.9, 150.7, 133.1, 132.7, 130.4, 124.4, 121.8, 118.5, 118.0, 73.6, 69.7, 54.6, 53.1, 50.5, 37.6, 36.6, 36.3, 29.2, 23.7, 21.6, 21.5. Example 200 Synthesis of V-(3,5-DifluorobenzenesulfonyI)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,iV- dimethylcarbamyloxy)phenylaIanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.77 - 7.71 (m, IH), 7.70 - 7.65 (m, IH), 7.40 - 7.31 (m, IH), 7.20 (d, 2H), 7.02 (d, 2H), 6.87 (d, IH), 5.05 (Sept, IH), 4.88 - 4.82 (m, IH), 4.55 (d, IH), 4.44 (d, IH), 3.91 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.23 (s, 3H), 1.18 (s, 3H). 13 C NMR (CDC1 3 ): δ 170.4, 167.9, 154.9, 150.7, 133.1, 132.7, 130.4, 124.4, 121.8, 118.5, 118.0, 73.6, 69.7, 54.6, 53.1, 50.5, 37.6, 36.6, 36.3, 29.2, 23.7, 21.6, 21.5. Example 201 Synthesis of 7V-(2,4-Difluorobenzenesulfonyl)-L-(5,5-dimethyI)thiaprolyl-L-4-( V, V- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.94 - 7.86 (m, IH), 7.20 (d, 2H), 7.03 (d, 2H), 7.02 - 6.95 (m, 2H), 6.88 (d, IH), 5.03 (Sept, IH), 4.82 (q, IH), 4.67 (d, IH), 4.61 (d, IH), 4.01 (s, IH), 3.16 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.36 (s, 3H), 1.23 (d, 3H), 1.21 (d, 3H), 1.20 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 167.9, 154.9, 150.7, 133.7, 132.8, 130.3, 121.8, 112.1, 106.1, 73.4, 69.6, 54.9, 53.2, 50.4, 37.6, 36.6, 36.3, 29.1, 23.9, 21.6, 21.5. Example 202 Synthesis of iV-(4-Chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N, V- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: Η NMR (CDCI 3 ): δ 7.82 (d, 2H), 7.53 (d, 2H), 7.21 (d, 2H), 7.02 (d, 2H), 6.93 (d, IH), 5.05 (Sept, IH), 4.89 - 4.82 (m, IH), 4.55 (d, IH), 4.41 (d, IH), 3.87 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.16 (s, 6H). 13 C NMR (CDCI 3 ): δ 170.3, 168.1, 154.9, 150.7, 140.4, 134.5, 132.8, 130.4, 129.7, 129.5, 121.8, 73.5, 69.6, 54.6, 53.1, 50.5, 37.6, 36.6, 36.3, 29.1, 23.8, 21.6, 21.0. Example 203 Synthesis of V-(3-Chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-( V,N- dimethyIcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: Η NMR (CDCI 3 ): δ 7.88 (t, IH), 7.78 - 7.75 (m, IH), 7.64 - 7.61 (m, IH), 7.51 (t, IH), 7.21 (d, 2H), 7.02 (d, 2H), 6.92 (d, IH), 5.05 (sept, IH), 4.89 - 4.82 (m, IH), 4.58 (d, IH), 4.40 (d, IH), 3.88 (s, IH), 3.18 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.16 (s, 3H), 1.14 (s, 3H). ,3 C NMR (CDCI 3 ): δ 170.3, 168.0, 154.9, 150.7, 137.7, 135.7, 133.9, 132.8, 130.7, 130.3, 127.9, 126.2, 121.8, 73.6, 69.96, 54.5, 53.2, 50.5, 37.6, 36.6, 36.3, 29.1, 23.7, 21.6, 21.5. Example 204 Synthesis of N-(2-Chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,iV- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: •H NMR (CDC1 3 ): δ 8.08 (dd, IH), 7.54 - 7.52 (m, 2H), 7.45 - 7.39 (m, IH), 7.19 (d, 2H), 7.02 (d, 2H), 6.79 (d, IH), 5.00 (sept, IH), 4.78 (d, IH), 4.75 - 4.68 (m, IH), 4.69 (d, IH), 4.19 (s, IH), 3.09 (s, 3H), 3.06 (d, 2H), 3.00 (s, 3H), 1.38 (s, 3H), 1.23 (s, 3H), 1.23 (d, 3H), 1.19 (d, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 168.1, 154.9, 150.7, 135.6, 134.4, 132.8, 132.7, 132.4, 130.3,127.3, 121.8, 73.3, 69.5, 54.7, 53.3, 50.4, 37.6, 36.6, 36.3, 29.6, 23.7, 21.6, 21.5. Example 205 Synthesis of 7V-(3,4-Dichlorobenzenesulfonyl)-L-(5,5-dimethyI)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: Η NMR (CDCI 3 ): δ 7.97 (d, IH), 7.70 (dd, IH), 7.63 (d, IH), 7.20 (d, 2H), 7.02 (d, 2H), 6.86 (d, IH), 5.05 (sept, IH), 4.89 - 4.82 (m, IH), 4.55 (d, IH), 4.43 (d, IH), 3.92 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.26 (d, 3H), 1.22 (d, 3H), 1.23 (s, 3H), 1.18 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 167.9, 154.9, 150.7, 138.7, 136.1, 134.2, 132.7, 131.4, 130.3, 129.8, 127.1, 121.8, 73.6, 69.7, 54.6, 53.1, 50.5, 37.5, 36.6, 36.3, 29.2, 23.7, 21.6, 21.5. Example 206 Synthesis of N-(3,5-Dichlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,7V- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting material. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.76 (d, 2H), 7.62 (t, IH), 7.20 (d, 2H), 7.03 (d, 2H), 6.85 (d, IH), 5.05 (sept, IH), 4.89 - 4.82 (m, IH), 4.57 (d, IH), 4.42 (d, IH), 3.92 (s, IH), 3.18 - 3.04 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.27 (s, 3H), 1.18 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 167.8, 154.9, 150.7, 139.1, 136.5, 133.7, 132.7, 130.3, 126.2, 121.8, 73.7, 69.7, 54.6, 53.1, 50.5, 37.5, 36.6, 36.3, 29.2, 23.7, 21.6, 21.5. Example 207 Synthesis of N-(3-Chlorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)-L- 4-( V,./V-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described in Example 92 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDCI 3 ): δ 7.85 (m, IH), 7.76 (m, IH), 7.63 (m, IH), 7.53 (m, IH), 7.06 (d, 2H), 6.96 (d, 2H), 6.37 (m, IH), 5.01 (m, IH), 4.62 (m, IH), 4.01 (m, 2H), 3.26 (m, IH), 3.06 (s, 3H), 2.96 (m, 7H), 1.49 (s, 9H). 13 C NMR (CDCI 3 ): δ 170.0, 164.5, 154.9, 150.6, 140.0, 136.1, 134.2, 132.5, 131.3, 130.2, 127.4, 125.5, 122.2, 82.8, 56.0, 53.3, 49.9, 49.2, 41.7, 36.5, 36.3, 36.0, 27.8. Example 208 Synthesis of J V-(3,4-DichlorobenzenesulfonyI)-L-(l,l-dioxothiamorpholin-3-carbonyI)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described in Example 92 by substitution of the appropriate starting materials. NMR data was as follows: 'H NMR (CDC1 3 ): δ 7.91 (m, IH), 7.66 (m, 2H), 7.06 (d, 2H), 6.94 (d, 2H), 6.33 (m, IH), 4.98 (m, IH), 4.60 (m, IH), 3.49 (m, 3H), 3.12 (m, 2H), 3.04 (s, 3H), 3.00 (m, 2H), 2.94 (s, 3H), 1.44 (s, 9H). !3 C NMR (CDC1 3 ): δ 170.0, 164.3, 154.8, 150.6, 138.8, 137.9, 134.3, 132.4 132.0, 130.3, 129.2, 126.4, 122.1, 83.0, 55.5, 53.1, 50.2, 49.5, 41.8, 36.5, 36.2, 36.0, 27.7. Example 209 Synthesis of N-(4-Methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaproIyl-L-4-(7V,7V- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDCI 3 ): δ 7.81 (d, 2H), 7.22 (d, 2H), 7.06 - 6.99 (m, 5H), 5.04 (sept, IH), 4.89 - 4.82 (m, IH), 4.56 (d, IH), 4.39 (d), 3.88 (s, 3H), 3.83 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.22 (d, 3H), 1.15 (s, 3H), 1.12 (s, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 168.5, 163.8, 154.9, 150.7, 132.9, 130.4, 130.3, 127.4, 121.7, 114.5, 73.5, 69.5, 55.6, 54.6, 53.2, 50.5, 37.7, 36.6, 36.3, 29.1, 23.9, 21.6, 21.5. Example 210 Synthesis of N-(3-MethoxybenzenesulfonyI)-L-(5,5-dimethyl)thiaprolyl-L-4-(NJV- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.47 - 7.45 (m, 2H), 7.37 - 7.36 (m, IH), 7.21 (d, 2H), 7.19 - 7.15 (m, IH), 7.04 - 6.98 (m, 3H), 5.04 (sept, IH), 4.88 - 4.82 (m, IH), 4.58 (d, IH), 4.40 (d, IH), 3.89 (s, IH), 3.87 (s, 3H), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.23 (d, 3H), 1.15 (s, 3H), 1.08 (s, 3H). 13 C NMR (CDC1 3 ): δ 170.3, 168.3, 160.2, 154.9, 150.7, 136.9, 132.9, 130.5, 130.4, 121.7, 120.2, 120.0, 112.6, 73.4, 69.6, 55.7, 54.5, 53.2, 50.4, 37.7, 36.6, 36.3, 29.1, 23.7, 21.6, 21.5. Example 211 Synthesis of 7V-(2-Methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(7V,N- dimethylcarbamyloxy)phenylaIanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: •H NMR (CDC1 3 ): δ 7.92 (dd, IH), 7.54 (dd, IH), 7.21 (d, 2H), 7.07 - 7.00 (m, 4H), 6.96 (d, IH), 5.01 (sept, IH), 4.83 - 4.76 (m, IH), 4.73 (d, IH), 4.61 (d, IH), 4.17 (s, IH), 3.93 (s, 3H), 3.14 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.36 (s, 3H), 1.22 (d, 3H), 1.21 (s, 3H), 1.19 (d, 3H). 13 C NMR (CDCI 3 ): δ 170.3, 168.7, 157.7, 154.9, 150.6, 135.4, 133.0, 132.5, 130.3, 125.2, 121.7, 120.5, 112.6, 73.3, 69.5, 56.0, 54.8,53.3, 50.4, 37.7, 36.6, 36.3, 29.2, 24.1, 21.6, 21.5. Example 212 Synthesis of N-(3,4-Dimethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,JV- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: 'H NMR (CDC1 3 ): δ 7.50 (dd, IH), 7.31 (d, IH), 7.21 (d, 2H), 7.05 - 7.01 (m, 3H), 6.97 (d, IH), 5.04 (sept, IH), 4.89 - 4.82 (m, IH), 4.56 (d, IH), 4.40 (d, IH), 3.95 (s, 3H), 3.94 (s, 3H), 3.89 (s, IH), 3.17 - 3.03 (m, 2H), 3.09 (s, 3H), 3.00 (s, 3H), 1.25 (d, 3H), 1.22 (d, 3H), 1.16 (s, 3H), 1.14 (s, 3H). ,3 C NMR (CDC1 3 ): δ 170.3, 168.5, 154.9, 153.5, 150.7, 149.4, 132.9, 130.4, 127.6, 122.3, 121.7, 110.6, 110.3, 73.5, 69.6, 56.3, 56.1, 54.6, 53.2, 50.5, 37.7, 36.6, 36.3, 29.2, 23.8, 21.6, 21.5. Example 213 Synthesis of N-(2,4-Difluorobenzenesulfonyl)-L-(thiamorpholin-3-carbonyl)-L-4- (N,N-dimethylcarbamyIoxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 49 by substitution of the appropriate starting material. NMR data was as follows: 'H NMR (CDC1 3 ): δ 7.89 (m, IH), 7.16 (m, 2H), 6.97 (m, 4H), 6.77 (d, IH), 4.72 (m, IH), 4.60 (m, IH), 3.92 (m, IH), 3.29 (m, IH), 3.09 (m, 5H), 2.93 (s, 3H), 2.70 (m, 2H), 2.55 (m, IH), 2.10 (m, IH), 1.42 (s, 9H). 13 C NMR (CDC1 3 ): δ 170.0, 168.0, 167.7, 137.1, 164.4, 164.3, 161.1, 160.9, 157.7, 157.5, 154.8, 150.5, 132.7, 132.6, 132.4, 130.4, 124.0, 123.8, 121.7, 112.2, 111.9, 106.5, 106.1, 105.8, 82.6, 55.4, 53.9, 43.5, 36.4, 36.2,27.7, 26.8, 25.5. Example 214 Synthesis of N-(3,4-Dichlorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)- L-4-(N, V-dimethylcarbamyIoxy)phenylalanine The title compound was prepared from the product of Example 208 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 8.04 (m, IH), 7.68 (m, 2H), 7.52 (m, IH), 7.21 (d, 2H), 7.02 (d, 2H), 5.22 (m, IH), 4.63 (m, IH), 4.22 (m, IH), 3.71 (m, IH), 3.57 (m, IH), 3.30 (m, 3H), 3.08 (s, 3H), 3.02 (m, 3H), 2.97 (s, 3H). ,3 C NMR (CD 3 OD): δ 174.0, 168.0, 156.9, 152.1, 140.7, 139.3, 135.2, 133.2, 131.6, 130.7, 128.3, 123.2, 57.2, 54.9, 54.6, 51.7, 51.4, 43.3, 37.3, 36.9, 36.7. Example 215 Synthesis of N-(3-ChIorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3-carbonyl)-L- 4-( V,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 207 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CD 3 OD): δ 7.94 (m, IH), 7.77 (m, 2H), 7.58 (m, IH), 7.46 (d, IH), 7.19 (d, 2H), 7.07 (d, 2H), 5.23 (m, IH), 4.63 (m, IH), 4.20 (m, IH), 3.71 (m, IH), 3.43 (m, IH), 3.26 (m, 4H), 3.17 (s, 3H), 2.95 (m, 5H). 13 C NMR (CD 3 OD): δ 168.0, 152.1, 142.5, 136.8, 135.0, 132.7, 131.6, 128.6, 127.1, 123.3, 57.2, 54.9, 51.4, 51.2, 43.2, 37.2, 36.8, 36.7. Example 216 Synthesis of N-(3-Chloro-4-fluorobenzenesulfonyl)-L-(l,l-dioxothiamorpholin-3- carbonyl)-L-4-(7V,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared using the procedure described in Example 92 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CD 3 OD): δ 7.93 (d), 7.90 (m), 7.29 (s), 7.27 (d), 7.04 (d), 4.60 (m), 4.46 (d), 3.90 - 3.40 (m), 3.10 (s), 2.98 (s), 1.43 (s). 13 C NMR (CD 3 OD): δ 171.5, 166.5, 156.9, 151.9, 135.2, 131.3, 129.9, 127.9, 127.8,123.1, 117.8, 117.5, 101.4, 83.7, 57.9, 56.0, 42.9, 37.3, 36.9, 36.7, 28.1. Example 217 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(thiamorpholin-3-carbonyl)-L-4- (ΛyV-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedures described for the preparation of Examples 49 and 117. NMR data was as follows: •H NMR (CDCI 3 ): δ 7.77 (s), 7.63 (s), 7.08 (d), 6.93 (d), 6.76 (d), 6.71 (d), 5.50 (d), 5.22 (s), 4.82 (t), 4.61 (q), 3.83 (s), 3.25 (dt), 3.04 (m), 2.90 (s), 2.05 (dd), 1.34 (s). 13 C NMR (CDCI 3 ): δ 169.3, 166.8, 154.7, 150.4, 138.4, 132.4, 132.2, 130.2, 121.4, 118.3, 105.4, 82.5, 55.2, 53.6, 53.3, 39.5, 38.3, 36.6, 36.3, 36.1, 27.6, 23.5. Example 218 Synthesis of N-(3,4-Difluorobenzenesulfonyl)-L-(thiamorphoIin-3-carbonyl)-L-4- ( V,N-dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Examples 49 by substitution of the appropriate starting materials. NMR data was as follows: ! H NMR (CD 3 OD): δ 7.88 (m, IH), 7.70 (m, IH), 7.57 (m, IH), 7.23 (d, 2H), 7.03 (d, 2H), 6.83 (d, IH), 5.63 (dd, IH), 5.07 (t, IH), 4.58 (m, IH), 3.22 - 3.00 (m, 3H), 3.09 (s, 3H), 2.98 (s, 3H), 2.07 (dd, IH), 1.44 (s, 9H). 13 C NMR (CD 3 OD): δ 171.3, 169.3, 156.9, 152.0, 135.0, 131.6, 126.5, 122.9, 120.2, 119.9, 119.4, 118.7, 118.4, 106.4, 83.6, 56.5, 55.6, 37.1, 36.8, 36.6, 28.1, 25.2. Example 219 Synthesis of N-(Toluene-4-sulfonyI)-L-(5,5-dimethyl)thioprolyl-L-(thiomorpholin-4- ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared using the procedure described in Example 82 by substitution of the appropriate starting materials. NMR data was as follows: 'H NMR (CDCI 3 ): δ 9.09 (s, IH), 8.88 (m, IH), 8.16 (m, IH), 7.50 (m, IH), 7.22 (d, 2H), 7.01 (d, 2H), 6.91 (d, IH), 5.05 (m, IH), 4.85 (m, IH), 4.60 (d, IH), 4.46 (d, IH), 3.89 (s, IH), 3.93 - 3.83 (m, 4H), 3.11 (m, 2H), 2.69 (m, 4H), 1.29 - 1.16 (m, 12H). 13 C NMR (CDCI 3 ): δ 170.3, 167.8, 154.3, 153.5, 150.4, 148.7, 135.8, 133.1, 132.9, 130.4, 124.0, 121.8, 73.7, 69.7, 54.7, 53.2, 50.5, 47.1, 46.4, 37.6, 29.1, 27.4, 27.0, 23.8, 21.6, 21.5. Example 220 Synthesis of N-(3,4-DifluorobenzenesuIfonyI)-L-(thiamorpholin-3-carbonyI)-L-4- ( V,N-dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 218 using the procedure described in Method 11. NMR data was as follows: 'H NMR (CDC1 3 ): δ 7.89 (s, IH), 7.57 - 7.46 (m, 2H), 7.35 (d, IH), 7.32 - 7.22 (m, IH), 7.09 (d, 2H), 6.91 (d, 2H), 6.64 (d, IH), 5.50 (d, IH), 4.89 (s, IH), 4.88 - 4.79 (m, IH), 3.17 - 3.02 (m, 3H), 3.02 (s, 3H), 2.93 (s, 3H), 1.75 (dd, IH). ,3 C NMR (CDC1 3 ): δ 173.6, 167.7, 155.5, 152.0, 151.8, 150.1, 148.4, 132.8, 130.4, 124.6, 121.5, 118.7, 118.5, 117.5, 117.3, 1 17.1, 106.9, 54.9, 53.0, 36.4, 36.2, 36.0, 23.4. Example 221 Synthesis of V-(2,5-Dichlorothiophene-3-sulfonyI)-L-(5,5-dimethyl)thiaprolyI-L-4- (N,7V-dimethylcarbamyloxy)phenyIalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.18 (d, 2H), 7.11 (s, IH), 7.00 (d, 2H), 6.87 (d, IH), 5.03 - 4.99 (m, IH), 4.84 - 4.81 (m, IH), 4.65 - 4.56 (m, 2H), 4.07 (s, IH), 3.10 - 3.01 (m, 5H), 2.98 (s, 3H), 1.37 (s, 3H), 1.22 (s, 3H), 1.21 (s, 3H), 1.18 (s, 3H). 13 C NMR (CDC1 3 ): δ 170.3, 167.7, 154.9, 150.7, 132.9, 132.8, 131.9, 130.3, 128.0, 127.0, 121.8, 73.4, 69.6, 54.8, 53.2, 50.5, 37.5, 36.6, 36.3, 29.1, 23.8, 21.6, 21.5. Example 222 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (thiomorpholin-4-ylcarbony!oxy)phenylaIanine Isopropyl Ester The title compound was prepared using the procedure described in Example 82 by substitution of the appropriate starting materials. NMR data was as follows: •H NMR (CDC1 3 ): δ 7.89 (s, IH), 7.80 (s, IH), 7.21 (d, 2H), 7.01 (m, 3H), 5.03 (m, IH), 4.83 (m, IH), 4.54 (d, IH), 4.40 (d, IH), 3.95 (s, 3H), 3.86 (m, 4H), 3.80 (s, IH), 3.09 (m, 2H), 2.68 (m, 4H), 1.28 (s, 3H), 1.22 (m, 6H), 1.16 (s, 3H). I3 C NMR (CDC1 3 ): δ 170.4, 168.3, 153.5, 150.4, 139.3, 133.3, 132.9, 130.4, 121.7, 117.6, 73.8, 69.7, 54.8, 53.2, 50.5, 47.1, 46.4 39.6, 37.6, 29.0, 27.4, 27.1, 24.0, 21.6, 21.5. Example 223 Synthesis of N-(8-Quinolinesulfonyl)-L-prolyl-L-4-(N,iV- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: •H NMR (CDC1 3 ): δ 9.01 - 8.99 (m, IH), 8.56 - 8.53 (m, IH), 8.27 - 8.23 (m, IH), 8.07 - 8.04 (m, IH), 7.66 - 7.61 (m, 2H), 7.55 - 7.51 (m, IH), 7.17 (d, 2H), 7.01 (d, 2H), 5.27 - 5.23 (m, IH), 5.07 - 4.98 (m, IH), 4.84 - 4.76 (m, IH), 3.34 - 3.20 (m, 3H), 3.06 - 2.98 (m, 4H), 2.97 (s, 3H), 2.15 - 2.09 (m, IH), 1.64 - 1.51 (m, 3H), 1.23 (d, 6H). 13 C NMR (CDC1 3 ): δ 172.0, 170.5, 154.9, 151.5, 150.6, 143.9, 136.8, 135.6, 134.9, 134.1, 133.3, 130.2, 129.2, 125.6, 122.3, 121.7, 69.3, 62.8, 53.5, 48.7, 37.3, 36.5, 36.3, 29.7, 24.3, 21.6, 21.6. Example 224 Synthesis of N-(8-Quinolinesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 223 using the procedure described in Method 7. NMR data was as follows: 'H NMR (CD 3 OD): δ 9.03 - 9.01 (m, IH), 8.49 - 8.42 (m, 2H), 8.23 - 8.20 (m, IH), 8.09 - 8.07 (m, IH), 7.73 - 7.61 (m, 2H), 7.25 (d, 2H), 7.00 (d, 2H), 5.30 - 5.27 (m, IH), 4.73 - 4.69 (m, IH), 3.38 - 3.21 (m, 3H), 3.09 - 3.02 (m, 4H), 2.95 (s, 3H), 1.86 (m, IH), 1.78 - 1.73 (m, IH), 1.58 - 1.50 (m, 2H). I3 C NMR (CD 3 OD): δ 175.3, 174.2, 164.7, 156.9, 152.9, 145.2, 138.5, 136.9, 135.8, 135.6, 131.6, 130.9, 126.9, 123.8, 122.9, 63.9, 54.7, 50.0, 37.5, 36.8, 36.7, 31.6, 25.5. Example 225 Synthesis of iV-(8-Quinolinesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N, V- dimethylcarbamyloxy)phenylalanine Isoproplyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 by substitution of the appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 9.05 - 9.03 (m, IH), 8.53 - 8.49 (m, IH), 8.26 - 8.22 (m, IH), 8.08 - 8.05 (m, IH), 7.65 - 7.60 (m, IH), 7.56 - 7.52 (m, IH), 7.19 (d, 2H), 7.06 (d, IH), 7.00 (d, 2H), 5.17 (d, IH), 4.94 (m, IH), 7.74 - 4.78 (m, 2H), 4.66 (s, IH), 3.08 - 2.99 (m, 8H), 1.20 - 1.16 (m, 12H). 13 C NMR (CDC1 3 ): δ 170.2, 168.9, 154.9, 151.5, 150.6, 144.2, 136.7, 134.4, 134.4, 133.1, 130.3, 129.2, 125.5, 122.3, 121.7, 73.2, 69.3, 54.8, 53.3, 50.6, 37.6, 36.6, 36.3, 29.2, 24.1, 21.5, 21.4. Example 226 Synthesis of N-(8-QuinolinesuIfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 225 using the procedure described in Method 7. NMR data was as follows: •H NMR (CD 3 OD): δ 9.06 - 9.04 (m, IH), 8.45 - 8.39 (m, 2H), 8.23 - 8.14 (m, IH), 7.72 - 7.61 (m, 2H), 7.32 (d, 2H), 7.03 (d, 2H), 5.12 (d, IH), 4.87 (d, IH), 4.69 - 4.64 (m, 2H), 3.28 - 3.02 (m, 5H), 2.98 (s, 2H), 1.18 (s, 3H), 1.08 (s, 3H). 13 C NMR (CD 3 OD): δ 174.1, 171.8, 157.1, 152.9, 152.0, 145.5, 138.4, 137.3, 135.8, 135.6, 135.1, 131.8, 130.9, 126.8, 123.8, 122.9, 73.7, 55.9, 54.8, 51.7, 37.6, 36.8, 36.7, 30.2, 25.0. Example 227 Synthesis of N-(3-Sulfonamido-4-chloro-benzenesuIfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 8.45 (d, IH), 7.91 (d, IH), 7.67 (d, IH), 7.13 (d, 2H), 7.06 (d, IH), 7.01 (d, 2H), 5.90 (brs, 2H), 5.06 - 5.02 (m, IH), 4.79 - 4.72 (m, IH), 4.14 - 4.10 (m, IH), 3.42 - 3.39 (m, IH), 3.25 - 3.14 (m, 2H), 3.07 (s, 3H), 3.04 - 2.97 (m, IH), 2.96 (s, 3H), 1.98 - 1.96 (m, IH), 1.72 - 1.62 (m, 3H), 1.28 - 1.25 (m, 6H). 13 C NMR (CDC1 3 ): δ 170.8, 170.7, 155.1, 150.6, 141.4, 136.9, 136.1, 132.9, 132.8, 131.9, 130.3, 128.7, 121.9, 69.8, 62.1, 53.3, 49.6, 36.9, 36.6, 36.4, 30.4, 24.3, 21.6, 21.6. Example 228 Synthesis of N-(Toluene-4-sulfonyl)-L-(l-oxothiomorpholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 182 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.77 (d, 2H), 7.72 (d, 2H), 7.33 (m, 2H), 7.20 (m, 2H), 7.12 (d, 2H), 7.01 (m, 2H), 5.10 (m, IH), 5.01 (m, IH), 4.84 (m, IH), 4.75 (m, IH), 3.80 (m, 3H), 3.05 (m, 4H), 2.96 (m, 3H), 2.74 (m, IH), 2.42 (m, 4H), 1.30 - 1.20 (m, 6H). 13 C NMR (CDC1 3 ): δ 170.6, 170.4, 166.8, 166.7, 154.9, 150.7, 150.6, 145.1, 144.8, 135.8, 135.5, 132.7, 130.6, 130.4, 130.3, 130.0, 127.7, 127.1, 122.4, 121.8, 69.8, 69.4, 55.8, 53.7, 52.9, 50.8, 48.2, 47.9, 42.0, 41.2, 38.4, 36.6, 36.5, 36.3, 31.2, 21.5, 21.5. Example 229 Synthesis of N-(2,4-Difluorobenzenesulfonyl)-L-(l-oxothiomorpholin-3-carbonyl)-L-4- (N,N-dimethylcarbamy loxy) phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 182 and substimtion of appropriate starting materials. NMR data was as follows: 'H NMR (CDCI 3 ): δ 7.91 (m, IH), 7.30 (m, 2H), 6.97 (m, 4H), 4.71 (m, IH), 4.55 (m, IH), 3.90 (m, 2H), 3.77 (m, IH), 3.11 (m, 4H), 2.85 (m, 3H), 2.80 (m, IH), 2.60 (m, 2H), 1.46 (s, 9H), 1.39 (s, 9H). 13 C NMR (CDC1 3 ): δ 170.0, 168.0, 167.9, 166.4, 166.2, 164.6, 164.4, 162.7, 161.4, 161.2, 157.9, 157.8, 154.8, 150.6, 150.4, 132.8, 132.5, 132.4, 130.9, 130.4, 130.1, 123.3, 123.1, 122.2, 121.6, 121.1 , 122.6, 122.2, 111.9, 106.6, 106.3, 105.9, 82.8, 82.3, 55.8, 54.1, 53.2, 51.6, 49.2, 48.7, 43.1, 42.3, 38.7, 36.5, 36.2, 31.8, 27.7. Example 230 Synthesis of N-(l-Methylpyrazole-4-suIfonyl)-L-(5,5-dimethyI)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine 2,2-Dimethylpropyl Ester The product from Example 161 (1 g. , 0.72 mmol) was dissolved in neopentyl alcohol (5 mL). Titanium (IV) isopropoxide (260 mg., 0.9 mmol) was added and the mixmre heated at 100 ° C under an inert atmosphere for 48h. Excess neopentyl alcohol was removed under reduced pressure and the residue purified by flash column chromatography (silica, 1 % MeOH in CHC1 3 ) to give the title compound as a white solid (1.02 g, 97%). Physical data was as follows: MS (+) ESI [M+H] + 610; [M+NH4] + 627 (100%). Anal. Calcd. For C 29 H 39 N 5 O 7 S: C, 53.18; H, 6.45; N, 11.49. Found: C, 53.46; H, 6.38; N, 11.06. Example 231 Synthesis of N-(Pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine 2,2-Dimethylpropyl Ester The product from Example 173 was subjected to the transesterification procedure described for the preparation of Example 230. The compound was purfied by flash column chromatography (silica, 1 % MeOH in CHC ) followed by recrystallization from ethyl acetate to give the title compound as a white solid (720 mg, 47%). Physical data was as follows: Anal. Calcd. For C 28 H 38 Ν 4 O 7 S 2 : C, 55.43; H, 6.31; N, 9.23. Found: C, 55.37; H, 6.32; N, 9.22. Example 232 Synthesis of N-(l-MethylpyrazoIe-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Cyclopropylmethyl Ester The product from Example 161 was subjected to the transesterification procedure described for the preparation of Example 230. The title compound was obtained as a white solid following flash column chromatography (silica, 1 % MeOH in CHCL) (860 mg, 70%). Physical data was as follows: Anal. Calcd. For C 26 H 35 N 5 O 7 S 2 : C, 52.6; H, 5.94; N, 11.8. Found: C, 52.49; H, 5.93; N, 11.62. Example 233 Synthesis of N-(l-Methylpyrazole-4-sulfonyI)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Methyl Ester The title compound was prepared following the procedure described for the preparation of Example 161 and substimtion of appropriate starting materials. Physical data was as follows: MS (+) ESI [M+H] + 554; [M+NH 4 ] + 571 (100%). Anal. Calcd. For C 23 H 31 N 5 O 7 S 2 • 0.2 EtOAc: C, 50.04; H, 5.75; N, 12.26. Found: C, 50.12; H, 5.69; N, 12.19. Example 234 Synthesis of N-(Pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Ethyl Ester The product from Example 173 was subjected to the transesterification procedure described for the preparation of Example 230. The compound was purified by flash column chromatography (silica, 2% MeOH in CHCL), followed by recrystallization from ethyl acetate to give the title compound as a white solid (1.2 g, 61 %). Physical data was as follows: Anal. Calcd. For C 25 H 32 N 4 O 7 S 2 : C, 53.18; H, 5.71; N, 9.92. Found: C, 53.14; H, 5.72; N, 9.57. Example 235 Synthesis of N-(Pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Cyclopropylmethyl Ester The product from Example 173 was subjected to the transesterification procedure described for the preparation of Example 230. The compound was isolated as a white solid following flash column chromatography (silica, 2% MeOH in CHC1 3 ) and recrystallization from EtOAc/hexanes (1 g, 65%). Physical data was as follows: Anal. Calcd. For C 27 H 34 N 4 O 4 S 2 : C, 54.9; H, 5.8; N, 9.48. Found: C, 54.77; H, 5.65; N, 9.46. Example 236 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyI)thiaprolyl-L-4-(N,V- dimethyIcarbamyloxy)phenylalanine 2-Methoxyphenyl Ester To a solution of the compound from Example 139 (1.79 g, 3.31 mmol), 2-methoxy-phenol (0.45 g, 3.64 mmol) and BOP (1.61 g, 3.64 mmol) in methylene chloride (25 mL) at 0°C was added triethylamine (0.7 mL, 4.97 mmol). The reaction mixmre was then slowly warmed to 25°C where it was stirred, under nitrogen, for 24 h. The reaction was quenched by addition of 100 mL samrated brine and extracted with EtOAc. The organic extract was washed sequentially with 2N HCl (3 times), samrated sodium bicarbonate (3x) and samrated brine (2x), dried over MgSO 4 , and evaporated to 2.1 g of crude product. Flash chromatography (eluant: 96-4 methylene chloride: EtOAc) afforded 1.85 g of a white solid which upon trimration with hexane gave 1.68 g (79%) of white crystals, mp 72-75 °C. Physical data was as follows: Anal. Calcd. For C 29 H 35 N 5 O 8 S 2 : C, 59.94; H, 5.46; N, 10.85. Found: C, 53.45; H, 5.62; N, 10.31. Example 237 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(iV,N- dimethylcarbamyloxy)phenylalanine n-Butyl Ester A solution of the compound of Example 139 (2 g) in «-butanol (50 mL) was samrated upon ice-cooling with HCl gas. The mixmre was stirred at ambient temperamre for 36 h, evaporated in vacuo to almost dryness, then partitioned between 5% NaHCO 3 and chloroform. The organic layer was dried and evaporated in vacuo to furnish 900 mg of the title compound. Physical data was as follows: MS: [(+)ESI], [M+H] + 596. Example 238 Synthesis of N-(l-Methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine n-Propyl Ester A solution of N-(l-methylpyrazole-4-sulfonyl)-L-(5,5- dimethyl)thiaprolyl-L-4-(NN-dimethylcarbamyloxy)phenylalanine (2 g) in n- propanol (50 mL) was saturated upon ice-cooling with HCl gas. The mixmre was stirred at ambient temperature for 36 hours, evaporated in vacuo to almost dryness, then pardoned between 5% ΝaHCC", and chloroform. The organic layer was dried and evaporated in vacuo to provide 1500 mg of the title compound. Physical data was as follows: MS: [(+)ESI], [M+H] + 582. Example 239 Synthesis of N-(l-Methylpyrazole-4-sulfonyI)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine 2,2-Dimethylpropionyloxymethyl Ester Potassium iodide (324 mg) was added at once to a mixmre of the compound of Example 139 (1.08 g), chloromethylpivalate (294 mg) and powdered K 2 CO 3 (222 mg) in DMF (5 mL). The reaction mixmre was stirred at ambient temperamre overnight, partitioned between water (12 mL) and ethyl acetate (60 mL). The separated organic layer was washed with ice cold 0.1 N sodium thiosulfate, water and brine, then dried over MgSO 4 , filtered and evaporated in vacuo to yield 750 mg of the title compound. Physical data was as follows: MS: [(+)ESI], [M+H] + 654. Example 240 Synthesis of V-(Toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylpiperazin-l- y!carbonyloxy)phenyIaIanine tert-Butyl Ester The title compound was prepared following the procedure outlined for Example 4 by substitution of the appropriate starting materials. A white solid was obtained, mp. 60-65°C. Physical data was as follows: MS (+ESI) 694.3 [M+NH 4 ] + . Anal. Calcd for C 36 H 44 N 4 O 7 S • 0.5C 4 H 8 O 2 : C, 63,31; H, 6.71; N, 7.77. Found: C, 63.12; H, 6.58; N, 7.69. Example 241 Synthesis of 7V-(Toluene-4-sulfonyl)-L-prolyl-L-4-(4'-(ethoxycarbonyI)piperidin-l- ylcarbonyloxy)phenylalanine tert-Butyl Ester The carbamate was prepared by treatment of Tos-Pro-Tyr-t-butyl ester with 4-nitrophenylchloroformate, followed by addition of ethylisonipecotate (triethylamine, methylene chloride, chilled to 0°C, then stirred at room temperature overnight). The crude product was purified by flash chromatography (silica, 95:5 EtoAc:Et 3 N) to afford a white solid. (.78 g, 39%). NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHz): δ 8.15 (d, IH, J - 7.68Hz); 7.70 (d, 2H, J = 8.34Hz); 7.40 (d, 2H, J = 7.90Hz); 7.22 (d, 2H, J = 8.56Hz); 7.00 (d, 2H, J = 8.56Hz); 4.37 (m, IH), 4.07 (q, 2H, J = 7.14, 14.08Hz); 4.03 (m, 2H); 3.90 (m, IH); 3.34 (m, IH); 3.09 (m, 2H); 3.00 (m, 3H); 2.59 (m, IH); 2.39 (s, 3H); 1.87 (m, 2H); 1.58 (m, 5H); 1.41 (m, IH); 1.35 (s, 9H); 1.18 (t, 3H, 7.14Hz). IR (KBr, cm "1 ): 3410, 2990, 2950, 1725, 1680, 1510, 1430, 1355, 1220, 1200, 1170, 1000, 675, 595. MS ((+)ESI, m/z (%)) 689 (100[M+NH 4 ] + ); 691 (37[M+NH 4 ] + ). Anal. Calc'd for C 34 H 45 N 3 O 9 S: C, 60.79; H, 6.75; N, 6.25. Found: C, 60.59; H, 6.67; N, 6.22. Example 242 Synthesis of N-(Toluene-4-sulfonyl)-L-proIyI-L-4-(N-(4'-(2'- aminoethyl)morpholino)carbamyloxy)phenylaIanine The title compound was prepared from the product of Example 152 using the procedure described in Method 11. NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHz): δ 12.75 (s, IH); 8.08 (d, IH); 7.68 (d, 2H); 7.60 (t, IH); 7.39 (d, 2H); 7.21 (d, 2H); 6.97 (d, 2H); 4.46 (m, IH); 4.08 (m, IH); 3.56 (m, 4H); 3.26 (m, 3H); 3.09 (m, 2H); 2.94 (m, IH); 2.49 (s, 6H); 2.48 (s, 3H); 1.5 (m, 3H); 1.38 (m, IH). IR (KBr, cm 1 ) 3400, 2975, 1725, 1650, 1500, 1350, 1150, 650, 575, 550. MS ((-)ESI, m/z (%)) 587 (100[M-H] + ). Anal. Calc'd for C 28 H 36 N 4 O 8 S.HCOOH.0.5H 2 O: C, 54.11; H, 6.11; N, 8.70. Found: C, 53.96; H, 6.02; N, 8.68. Example 243 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI-L-4-[4-(carboxy)piperidin-l- ylcarbonyloxy]phenylalanine The title compound was prepared from the product of Example 241 using the procedures described in Methods 6 and 11. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz): δ 12.50 (bs, 2H); 8.08 (d, IH, J = 7.90Hz); 7.69 (d, 2H, J = 8.34Hz); 7.39 (d, 2H, J = 7.90Hz); 7.22 (D, 2H, J = 8.56 Hz); 6.99 (d, 2H, J = 8.56 Hz); 4.46 (m, IH); 4.09 (m, IH); 4.00 (m, IH); 3.90 (m, IH); 3.30 (m, IH); 3.09 (m, 3H); 2.95 (m, 2H); 2.49 (m, IH); 2.38 (s, 3H); 1.86 (m, 2H); 1.36-1.61 (m, 6H). IR (KBr, cm 1 ) 3400, 2960, 1720, 1535, 1430, 1350, 1200, 1160, 670, 590, 550. MS ((+)ESI, m/z (%)) 605 (100IM+NHJ + ). Anal. Calc'd for C 28 H 33 N 3 O 9 S H 2 O: C, 55.53; H, 5.65; N, 6.94. Found: C, 55.23; H, 5.82; N, 6.59. Example 244 Synthesis of N-(ToIuene-4-sulfonyl)-L-prolyl-L-4-(N,N-bis-(2- hydroxyethyl)carbamyloxy)phenylalanine Isopropyl Ester The carbamate was prepared by treatment of Tos-Pro-Tyr-iPr ester with 4-nitrophenyl chloroformate, followed by addition of diethanol amine (triethylamine, methylene chloride, chilled to 0°C, stirred at room temperamre overnight). The crude product was purified by flash chromatography (silica, 98:2 EtOAc:EtOH) to afford a white foam. (0.180g, 28%). NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz): δ 8.26 (d, IH, J = 7.90Hz); 7.69 (d, 2H, J = 8.12Hz); 7.40 (d, 2H, J = 8.12Hz); 7.23 (D, 2H, J = 8.56 Hz); 6.99 (d, 2H, J = 8.56Hz); 4.87 (m, IH); 4.83 (t, IH, J = 5.49Hz); 4.76 (t, IH, J = 5.49Hz); 4.42 (m, IH); 4.08 (m, IH); 3.58 (m, 2H); 3.51 (m, 2H); 3.44 (m, 2H); 3.34 (m, 3H); 2.99 - 3.09 (m, 3H); 2.39 (s, 3H); 1.59 (m, 3H); 1.41 (m, IH); 1.16 (d, 3H, J = 6.15Hz); 1.12 (d, 3H, J = 6.15Hz). IR (KBr, cm 1 ) 3420, 2940, 1725, 1535, 1670, 1520, 1460, 1410, 1350, 1220, 1160, 1110, 670, 600, 550. MS ((+)ESI, m/z (%)) 606 (15[M+H] + ); 623 (100[M+NH 2 ] + ). Anal. Calc'd for C 29 H 39 N 3 O 9 S H 2 O: C, 56.66; H, 6.56; N, 6.84. Found: C, 56.66; H, 6.41; N, 6.72. Example 245 Synthesis of N-(Toluene-4-suIfonyl)-L-prolyl-L-4-[3-(hydroxymethyl)piperidin-l- ylcarbonyloxy] phenylalanine Isopropyl Ester The carbamate was prepared by treatment of Tos-Pro-Tyr-iPr ester with 4-nitrophenyl chloroformate, followed by addition of 3-piperidine methanol (triethylamine, methylene chloride, chilled to 0°C, stirred at room temperamre overnight). The crude product was purified by flash chromatography (silica, 3:2 EtOAc: Hex) to afford a white foam (0.519g, 67%). NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHz): δ 8.26 (d, IH, J = 7.90Hz); 7.69 (d, 2H, J = 8.12Hz); 7.40 (d, 2H, J = 8.12Hz); 7.22 (d, 2H, J = 8.56Hz); 6.98 (d, 2H, J = 8.34Hz); 4.85 (M, IH); 4.57 (bs, IH); 4.42 (m, IH); 3.99 - 4.09 (m, 3H); 3.85 (m, IH); 3.31 (m, IH); 3.22 (m, IH); 2.91 - 3.10 (m, 4H); 2.80 (m, IH); 2.55 (m, IH); 2.39 (s, 3H); 1.51 - 1.72 (m, 6H); 1.42 (m, 2H); 1.16 (d, 3H, J = 6.15Hz); 1.11 (d, 3H), J = 6.15Hz). IR (KBr, cm 1 ) 3400, 2990, 2940, 2880, 1725, 1520, 1430, 1350, 1220, 1165, 1100, 660, 600, 550. MS ((-)ESI, m/z (%)) 614 (30[M-H]). Anal. Calc'd for C 31 H 41 N 3 O 8 S: C, 60.47; H, 6.71; N, 6.82. Found: C, 59.83; H, 6.61; N, 6.59. Example 246 Synthesis of N-(Toluene-4-sulfonyI)-L-prolyl-L-4-(4- trifluoromethanesulf onylpiperazin- 1 -ylcarbonyloxy) phenylalanine tert- Butyl Ester The title compound was prepared following the procedure outlined for Example 128 and substitution of appropriate starting materials. Physical data was as follows: MS (+ESI):733 [M+H] + . Anal. Calc'd for C 31 H 39 F 3 N 4 O 9 S 2 • 0.10 C4H8O2: C,50.20; H, 5.40; N, 7.55. Found: C, 50.25; H, 5.46; N, 7.07. Example 247 Synthesis of N-(4-(N-Phenylurea)benzenesulfonyl)-L-prolyl-L-4-(N,N- dimethy!carbamyloxy)phenylalanine tert-Butyl Ester A mixmre of Example 107 (250 mg, 0.51 mmol), phenyl isocyanate (62 mg, 0.56 mmol) and triethylamine (76 μL, 0.56 mmol) was heated to reflux under argon. Reflux was continued overnight. Solvent was removed under reduced pressure and the residue purified by flash chromatography. (silica, hexanes: EtOAc 1 :1 then EtOAc) to give the title compound as an off-white foam (160 mg, 46%), mp 112-115°C. Physical data was as follows: MS (+ESI) [M+NHJ + 697 (100%). Example 248 Synthesis of N-(2-Trifluoroacetyl-l,2,3,4-tetrahydroisoquinolin-7-sulfonyl)-L-prolyl- L-4-(N,N-dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.70 - 7.66 (m, 2H), 7.35 - 7.30 (m, IH), 7.27 - 7.21 (m, IH), 7.14 - 7.10 (m, 2H), 7.01 (d, 2H), 5.09 - 4.95 (m, IH), 4.89 - 4.75 (m, 2H), 4.14 - 4.07 (m, IH), 3.93 - 3.85 (m, 2H), 3.35 - 3.20 (m, 2H), 3.13 - 2.97 (m, 9H), 2.05 - 2.01 (m, IH), 1.63 (1.50 (m, 3H), 1.20 (d, 6H). 13 C NMR (CDC1 3 ): δ 170.7, 170.6, 170.5, 156.3, 155.8, 154.9, 150.6, 140.1, 139.2, 135.1, 135.1, 13.2, 133.0, 133.0, 132.9, 130.2, 130.1, 129.9, 126.9, 126.4, 126.3, 125.8, 121.7, 118.3, 114.5, 69.6, 62.1, 62.0, 53.2, 49.6, 46.6, 46.5, 45.1, 42.7, 40.9, 37.1, 36.6, 36.3, 30.1, 30.0, 29.2, 27.8, 24.2, 24.2, 21.6, 21.6. Example 249 Synthesis of N-(l-Methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamy loxy) phenylalanine Isopropyl Ester Substimting N-methylpyrazole-3 -sulfonyl chloride (See European Patent Application, 095925) and following the method for the preparation of Example 56, gave the title compound. ΝMR data was as follows: Η ΝMR (CDC1 3 ): δ 7.45 (d, IH), 7.21 (d, 2H), 7.09 (d, IH), 7.01 (d, 2H), 6.71 (d, IH), 5.03 - 4.98 (m, IH), 4.87 - 4.84 (m, IH), 4.60 - 4.59 (m, 2H), 4.05 (s, IH), 3.97 (s, 3H), 3.12 - 3.01 (m, 5H), 2.98 (s, 3H), 1.22 - 1.15 (m, 12H). 13 C ΝMR (CDC1 3 ): δ 170.3 , 168.3, 154.9, 150.7, 146.7, 133.0, 131.9,130.3, 121.7, 108.9, 73.5, 69.5, 54.7, 53.3, 50.7, 39.9, 37.7, 36.6, 36.3, 28.8, 24.1, 21.5, 21.5. Example 250 Synthesis of N-(l-Methylpyrazole-3-suIfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 249 using the procedure described in Method 7. NMR data was as follows: Η NMR (CD 3 OD): δ 8.25 (d, IH), 7.76 (d, IH), 7.32 (d, 2H), 7.01 (d, 2H), 6.70 (d, IH), 4.74 - 4.71 (m, IH), 4.68 (d, IH), 4.56 (d, IH), 4.12 (s, IH), 3.97 (s, 3H), 3.24 - 3.07 (m, 5H), 2.97 (s, 3H), 1.14 (s, 3H), 1.13 (s, 3H). 13 C NMR (CD 3 OD): δ 174.1, 171.4, 157.0, 151.9, 148.2, 135.7, 134.2, 131.8, 122.9, 109.6, 74.4, 55.6, 55.0, 51.5, 40.0, 37.6, 36.8, 36.7, 29.6, 24.8. Example 251 Synthesis of N-(Pyridine-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure outlined for the preparation of Example 56, where 4-pyridinesulfonyl chloride N-oxide was used in place of 3-pyridinesulfonyl chloride (see Marsais and coworkers, J. Org. Chem. 1987, 52, 1133-1136). Deoxygenation of the N-oxide was accomplished using the procedure of Aoyagi and coworkers, Synthesis 1997, 891. NMR data was as follows: Η NMR (CDC1 3 ): δ 8.89 - 8.87 (m, 2H), 7.72 - 7.70 (m, 2H), 7.19 (d, 2H), 7.01 (d, 2H), 6.79 (d, IH), 5.05 - 5.01 (m, IH), 4.85 - 4.82 (m, IH), 4.58 (d, IH), 4.45 (d, IH), 3.91 (s, IH), 3.11 - 3.02 (m, 5H), 2.99 (s, 3H), 1.28 - 1.16 (m, 12H). 13 C NMR (CDC1 3 ): δ 170.3, 167.7, 154.9, 151.5, 150.7, 144.2, 132.7, 130.3, 121.8, 120.9, 73.6, 69.7, 54.6, 53.1, 50.4, 37.5, 36.6, 36.3, 29.1, 23.6, 21.6, 21.5. Example 252 Synthesis of N-(Pyridine-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 251 using the procedure described in Method 7. NMR data was as follows: Η NMR (CD 3 OD): δ 8.78 (d, 2H), 7.42 (d, IH), 7.69 (d, 2H), 7.35 (d, 2H), 7.06 (d, 2H), 4.69 - 4.61 (m, 3H), 4.16 (s, IH), 3.25 - 3.19 (m, IH), 3.13 - 3.05 (m, 4H), 2.97 (s, 3H), 1.25 (s, 6H). 13 C NMR (CD 3 OD): δ 174.1, 170.5, 157.0, 152.2, 152.0, 147.2, 135.8, 131.8, 123.1, 122.7, 73.9, 55.6, 54.9, 54.4, 37.5, 36.8, 36.7, 30.1, 24.8. Example 253 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamy loxy) phenylalanine tert-Butyl Ester A solution of the starting acid (500 mg), (2S)-2-amino-3-{4-[(2- dimethylaminoethyl)-methylcarbamoyloxy]phenyl}propionic acid tert-butyl ester (730 mg), HOBt (235 mg), and 4-methylmoφholine (0.87 mL) in DMF (10 mL) was stirred in ice bath at 0°C. l-[3-(Dimethylamino)propyl]-3- ethylcarbodiimide hydrochloride (360 mg) was added to the solution. The ice bath was removed after 10 minutes. The reaction was stirred at room temperamre for 3 hours. Ethyl acetate (20 mg) was added. The solution was washed with samrated NaHCO 3 solution (30 mL) 2 times, then washed with brine. The solution was dried with MgSO 4 . The solvent was evaporated in vacuo, and the residue flash chromatographed on silica gel to give 385 mg of the title compound. Physical data was as follows: MS: [(+)ESI], [M+H] + 663. Example 254 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(N-methyl-N-(2- dimethylaminoethyI)carbamy loxy) phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 253 and substitution of appropriate starting materials. Physical data was as follows: MS: [(+)ESI], [M+H] + 617. Example 255 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiapropyI-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamyloxy)phenylalanine The title compound was prepared from the product of Example 253 using the procedure described in Method 11. Physical data was as follows: MS: [(+)ESI], [M+H] + 607. Example 256 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamyloxy)phenylalanine The title compound was prepared from the product of Example 254 using the procedure described in Method 11. Physical data was as follows: MS: [(+)ESI], [M+H] + 561. Example 257 Synthesis of N-(4-FluorobenzenesulfonyI)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- methy!piperazin-l-ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials, mp: 64-67°C. Physical data was as follows: MS: [M+H] + 699. Anal. Calcd. for C 31 H 40 C1FN 4 O 7 S 2 • H 2 0: C, 51.90; H, 5.9; N, 7.8. Found: C, 51.53; H, 5.50; N, 7.62. Example 259 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (N,N-dimethycarbamyIoxy)phenylalanine The title compound was prepared for the product of Example 258 using the procedure described in Method 11. Physical data was as follows: MS: [M + LJ 603. Anal. Calcd. for C 24 H 27 FN 3 O 7 S 2 : C, 49.02; H, 4.63; N, 7.15. Found: C, 49.25; H, 4.89; N, 6.73. Example 260 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyI)thiaprolyl-L-3-chloro-4- (thiomorpholin-4-ylcarbonyloxy)phenyla!anine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 82 and substimtion of appropriate starting materials , mp .111 - 114°C . Physical data was as follows: MS: +ESI [M+NH4] + 719. Anal. Calcd. for C 30 H 37 C1FN 3 O 7 S: C, 50.02; H, 5.46; N, 5.8. Found: C, 50.23; H, 5.10; N, 5.50. Example 261 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (thiomorpholin-4-ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 82 and substimtion of appropriate starting materials, mp. 77-81°C. Physical data was as follows: MS: [M+NHJ + 705. Anal. Calcd. for C 29 H 35 ClFN 3 O 7 S 3 : C, 50.61; H, 5.13; N, 6.1. Found: C, 50.33; H, 5.07; N, 5.94. Example 262 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (/V,N-dimethylcarbamyloxy)] phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials, mp. 65-69°C. Physical data was as follows: MS: [M+NH 4 ] + 647. Anal. Calcd. for C^H^CIF^O^: C, 51.46; H, 5.28; N, 6.4. Found: C, 51.29; H, 5.19; N, 6.50. Example 263 Synthesis of N-(Toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials, mp. 68-72°C. Physical data was as follows: MS: [M+H] + 626. Anal. Calcd. for C 28 H 36 ClN 3 O 7 S 2 : C, 53.77; H, 5.80; N, 6.71. Found: C, 53.26; H, 5.8; N, 6.63. Example 264 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- methylpiperazin-l-ylcarbonyloxy)]phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. Physical data was as follows: MS: [M+H] + 685. Anal. Calcd. for C 30 H 38 C1N 4 O 7 : C, 52.59; H, 5.59; N, 8.18. Found: C, 52.09; H, 5.48; N, 7.77. Example 265 Synthesis of N-(ToIuene-4-sulfonyl)-L-prolyl-L-3-chloro-4-(N,N- dimethylcarbamyloxy)]phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. Physical data was as follows: MS: [M+H] + 580. Anal. Calcd. for C 27 H 34 ClN 3 O 7 S • 0.5 H 2 0: C, 55.04; H, 6.00; N, 7.13. Found: C, 55.06; H, 5.71; N, 6.93. Example 266 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- (2'-pyridyl)-piperazin-l-ylcarbonyloxy)]phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. Physical data was as follows: MS: [M+H] + 748. Anal. Calcd. for C 34 H 39 ClFN 5 O 7 S 2 : C, 54.57; H, 5.25; N, 9.3. Found: C, 54.26; H, 5.10; N, 9.07. Example 267 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyI-L-3-chloro-4-(4- (2'-pyridyl)-piperazin-l-ylcarbonyloxy)]phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials, mp. 80-86°C. Physical data was as follows: MS: [M+H] + 762. Anal. Calcd. for C 35 H 41 ClFN 5 O 7 S 2 : C, 55.14; H, 5.42; N, 9.19. Found: C, 54.67; H, 5.40; N, 8.69. Example 268 Synthesis of N-(4-Nitrobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylaIanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. Physical data was as follows: Anal. Calcd. for C 26 H 32 N 4 O 9 S: C, 54.16; H, 5.59; N, 9.72. Found: C, 53.69; H, 5.24; N, 9.52. Example 269 Synthesis of N-(4-Aminobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared from the product of Example 268 using the procedure described in Method 4. Physical data was as follows: Anal. Calcd. for C 26 H 34 N 4 O 7 S: C, 57.13; H, 6.27; N, 10.25. Found: C, 56.30; H, 6.12; N, 10.05. Example 270 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 82 and substimtion of appropriate starting materials. Physical data was as follows: Anal. Calcd. for C 29 H 37 N 3 O 7 S 2 : C, 57.69; H, 6.18; N, 6.96. Found: C, 57.36; H, 5.99; N, 6.76. Example 271 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylcarbamyIpiperazin-l- ylcarbonyloxy) phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: J H NMR (DMSO-cL., 400 MHz): δ 8.62 (s, IH); 8.11 (d, IH); 7.73 (d, 2H); 7.45 (m, 4H); 7.26 (m, 3H); 7.04 (m, 2H); 6.95 (m, IH); 6.25 (d, IH); 4.90 (m, IH); 4.50 (m, IH); 4.11 (m, IH); 3.6 (br, 4H); 3.4 (br, 4H); 3.10 (m, 2H); 3.00 (m, IH); 2.40 (s, 3H); 1.60 (m, 3H); 1.40 (m, IH); 1.18 (d, 3H); 1.12 (d, 3H). IR (KBr, cm 1 ) 3400-3500(br), 2950, 2900, 1725, 1650, 1540, 1450, 1240, 1210, 1000, 760, 675, 580, 540. MS ((+)ESI, m/z (%)) 706 (100 [M+H] + ). Anal. Calcd. for C 36 H 43 N 5 O 8 S.0.35 EtOAc: C, 60.98; H, 6.27; N, 9.51. Found: C, 50.31; H, 6.16; N, 9.33. Example 272 Synthesis of N-(Toluene-4-suIfonyl)-L-prolyl-L-4-(4-phenylcarbamylpiperazin-l- y lcarbonyloxy) phenylalanine The title compound was prepared from the product of Example 271 using the procedure described in Method 7. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz): δ 12.8 (s, 1H); 8.62 (s, IH); 8.11 (d, IH); 7.73 (d, 2H), 7.45 (m, 4H); 7.26 (m, 3H); 7.04 (m, 2H); 6.95 (m, IH); 6.25 (d, IH); 4.50 (m, IH); 4.11 (m, 1H); 3.6 (br, 4H); 3.4 (br, 4H); 3.10 (m, 2H); 3.00 (m, IH); 2.40 (s, 3H); 1.60 (m, 3H); 1.40 (m, IH). IR (KBr, cm 1 ) 3400, 1725, 1650, 1540, 1450, 1240, 1210, 1000, 760, 675, 580, 540. MS ((-)ESI, m/z (%)) 662 (100 [M-H] + ). Example 273 Synthesis of N-(l-n-ButylpyrazoIe-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 137 and substitution of appropriate starting materials. NMR data was as follows: Η NMR (CDC1 3 ): δ 7.89 (s, IH), 7.83 (s, IH), 7.21 (d, 2H), 7.06 (d, IH), 7.02 (d, 2H), 5.04 (sept, IH), 4.89 - 4.82 (m, IH), 4.57 (d, IH), 4.41 (d, IH), 4.16 (t, 2H), 3.78 (s, IH), 3.14 (dd, IH), 3.06 (dd, IH), 3.09 (s, 3H), 3.00 (s, 3H), 1.85 (pent, 2H), 1.36 - 1.23 (m, 2H), 1.27 (s, 3H), 1.24 (d, 3H), 1.21 (d, 3H), 1.16 (s, 3H). 13 C NMR (CDC1 3 ): δ 170.4, 168.3, 154.9, 150.7, 139.2, 131.8, 130.3, 121.8, 117.0, 73.8, 69.6, 54.8, 53.2, 52.7, 50.6, 37.7, 36.6, 36.3, 31.8, 28.9, 24.0, 21.6, 21.5, 19.4, 13.3. Example 274 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-(pyridin-4-ylcarbonyl)piperazin-l- ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz): δ 8.69 (dd, 2H), 8.28 (d, IH); 7.71 (d, 2H); 7.43 (m, 4H); 7.26 (d, 2H); 7.04 (d, 2H); 4.86 (m, IH); 4.42 (m, IH); 4.05 (m, IH); 3.4-3.8 (brm, 9H); 3.05 (m, 3H); 2.40 (s, 3H); 1.60 (m, 3H); 1.40 (m, IH); 1.18 (d, 3H); 1.15 (d, 3H). IR (KBr, cm 1 ) 3400, 1725, 1650, 1510, 1200, 1160, 1100, 1010, 650, 600, 550. MS ((+)ESI, m/z (%)) 692 (100 [M+H] + ). Anal. Calcd. for C 35 H 41 N 5 O 9 S. 0.75H 2 0: C, 59.60; H, 6.07; N, 9.93 Found: C, 59.45; H, 5.86; N, 9.88. Example 275 Synthesis of N-(Toluene-4-suIfonyl)-L-4-oxoprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 164 using the procedure described in Method 11. Physical data was as follows: MS [(-)ESI] [M-H]) 516. Example 276 Synthesis of N-(Toluene-4-sulfonyl)-L-frαn5-4-hydroxyprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 165 using the procedure described in Method 11. Physical data was as follows: Example 277 Synthesis of N-(4-Cyanobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials, mp. 166-167°C. Example 278 Synthesis of N-(4-AminobenzenesulfonyI)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 107 using the procedure described in Method 11. Physical data was as follows: Anal. Calcd. For C^ S: C, 47.34; H, 4.84;N, 9.60. Found: C, 47.57; H, 5.20; N, 8.75. Example 279 Synthesis of N-(Toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenyla!anine tert-Butyl Ester Acetonitrile (3 mL) was cooled to -40 °C (CH 3 CN/dry ice). Oxalyl chloride (0.10 mL) was added. N-(Toluene-4-sulfonyl)-L-4-hydroxyprolyl- L-4-(4-methy lpiperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester (300 mg) and dry DMSO (.008 mL) were dissolved in acetonitrile (4 mL) and were added to the above solution. The reaction was stirred at -40 °C for half an hour under dry conditions. Triethylamine (0.33 mL) was added to the solution. The dry ice bath was removed after 5 minutes. The reaction was stirred at room temperamre for 1 hour. The solvent was evaporated in vacuo, and ethyl acetate (15 mL) was added. The mixmre was washed with water (3x), then washed with brine. The solution was dried over MgSO 4 . The solvent was evaporated in vacuo, and the residue was flushed on a silica gel column to give 150 mg of the title compound, mp. 84-85°C. Example 280 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyI-L-4-[3-(hydroxymethyl)piperidin-l- ylcarbonyloxy]phenylalanine The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials, mp. 84-85°C. Example 281 Synthesis of N-(Toluene-4-sulfonyl)-L-(4,4-difluoro)prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 2 and substimtion of appropriate starting materials. Physical data was as follows: MS: [(+)ESI], [M+NH.r 599. Example 282 Synthesis of N-(Toluene-4-sulfonyl)-L-(4,4-difluoro)prolyl-L-4-(iV,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 281 using the procedure described in Method 7. Physical data was as follows: MS: [(+)ESI], [M+NHJ 557. Example 283 Synthesis of N-(ToIuene-4-sulfonyl)-L-prolyl-L-(4-benzoylpiperazin-l- ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (DMSO-d 6 , 400 MHz): δ 8.27 (d, IH); 7.69 (d, 2H); 7.45 (m, 7H); 7.24 9d, 2H); 7.02 (d, 2H); 4.86 (m, IH); 4.42 (m, IH); 4.07 (m, IH); 3.65 (br s, 4H); 3.45 (br s, 4H); 3.35 (m, IH); 3.05 (m, 3H); 2.38 (s, 3H); 1.60 (m, 3H); 1.40 (m, IH); 1.18 (d, 3H); 1.11 (d, 3H). IR (KBr, cm 1 ) 3400, 1725, 1675, 1625, 1510, 1425, 1350, 1250, 1175, 1110, 1010, 700, 660, 590, 550. MS ((+)ESI, m/z (%)) 708 (100 [M+NH 2 ] + ). Anal. Calcd. for C 36 H 42 N 4 O 8 S.0.5H 2 O: C, 61.79; H, 6.19; N, 8.01. Found: C, 61.64; H, 6.10; N, 7.72. Example 284 Synthesis of N-(l-Methyl-lH-imidazole-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine Isopropyl Ester The carbamate was prepared by treatment of 1 -methy limidazole-4- sulfonyl-Pro-Try-iPr ester with 4-nitrophenyl chloroformate, followed by addition of dimethylamine (triethylamine, methylene chloride, 0°C, stirred at room temperamre overnight.) The crude product was purified by flash chromatography (silica, 95:3:2 EtOAc: EtOH ;Et 3 N), followed by recrystallization from EtOAc. A white solid was obtained, mp 162-164°C (8.7g, 66%). Physical data was as follows: Anal. Calcd. for C 24 H 33 N 5 O 7 S: C, 53.82; H, 6.21; N, 13.08. Found: C, 53.47; H, 6.13; N, 12.96. Example 286 Synthesis of N-(Toluene-4-sulfonyl)-L-4-(thiomorpholin-4-ylcarbonyloxy)prolyl-L-4- (thiomorpholin-4-ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 285 using the procedure described in Method 11, mρ. H6-118°C. Example 287 Synthesis of N-(4-CyanobenzenesuIfonyl)-L-prolyl-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials, mp. 70-71°C. Example 288 Synthesis of N-(4-Amidinobenzenesulfonyl)-L-prolyl-L-4-(iV,N- dimethylcarbamyloxy)phenylalanine Methyl Ester Methanol (dry) was cooled to 0°C. HCl was bubbled in the solution for 15 minutes to make a samrated solution. Example 277 was added and the reaction mixmre was stirred at 0°C for 30 minutes then at room temperamre for 24 hours. The solvent was evaporated. NH 3 in methanol (2M, 5mL) was added. The reaction was stirred at room temperamre for 24 hours. The solvent was evaporated. The residue was purified by reverse phase HPLC in CH 3 CN:H 2 O (20:80). At a retention time of 12.45 minutes, the product was isolated and freeze-dried to provide the title compound. NMR data was as follows: Η NMR (in DMSO) multiplet at 1.47 - 1.55 ppm (IH), 1.63 - 1.72 ppm (3H's), singlet at 2.87 ppm (3H's), singlet at 3.02 ppm (3H's), multiplet at 3.05 - 3.10 ppm (2H's), multiplet at 3.17 - 3.22 ppm (IH), multiplet at 3.37 - 3.42 ppm (IH), singlet at 3.62 ppm (3H's), multiplet at 4.21 - 4.23 ppm (IH), quartet at 4.48 - 4.56 ppm (IH), doublet at 7.00 - 7.03 ppm (2H's), doublet at 7.23 - 7.26 ppm (2H's), a broad peak at 7.20 - 7.50 ppm, doublet at 8.02 - 8.03 ppm (4H's), doublet at 8.48 - 8.52 ppm (IH). Example 289 Synthesis of N-(Toluene-4-sulfonyl)-L-4-hydroxyprolyl-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials, mp. 80-82°C. Example 290 Synthesis of N-(Toluene-4-sulfonyI)-L-4-hydroxyprolyl-L-4-(thiomorphoIin-4- ylcarbonyloxy)phenylalanine N-(Toluene-4-sulfonyl)-L-4-hydroxyprolyl-L-4-(thiomoφholin-4- ylcarbony loxy )pheny lalanine tert-butyl ester (160 mg) was dissolved in formic acid (7 mL). The reaction was stirred at room temperamre for 6 hours. The solvent was evaporated and the residue purified using reverse phase HPLC in 20:80 CH 3 CΝ/water. At a retention time of 5.85 minutes, 50 mg of the title compound was obtained, mp. 170-172°C. Example 291 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-(4-benzoylpiperazin-l- ylcarbonyloxy)phenylalanine The title compound was prepared from the product of Example 283 using the procedure described in Method 11. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz): δ 12.8 (s, IH); 8.27 (d, IH); 7.69 (d, 2H); 7.45 (m, 7H); 7.24 (d, 2H); 7.02 (d, 2H); 4.42 (m, IH); 4.07 (m, IH); 3.65 (br s, 4H); 3.45 (br s, 4H); 3.35 (m, IH); 3.05 (m, 3H); 2.38 (s, 3H); 1.60 (m, 3H); 1.40 (m, IH). IR (KBr, cm 1 ) 3400, 1725, 1675, 1625, 1510, 1425, 1350, 1260, 1175, 1110, 1010, 700, 660, 590, 550. MS ((+)ESI, m/z (%)) 666 (100 [M+NHJ + ). Anal. Calcd. for C 33 H 36 N 4 O 8 S.0.66H 2 O: C, 60.00; H, 5.69; N, 8.48 Found: C, 60.36; H, 5.70; N, 7.81. Example 292 Synthesis of N-(4-Amidinobenzenesulfonyl)-L-prolyl-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine Methyl Ester The title compound was prepared following the procedure described for the preparation of Examples 287 and 288. Physical data was as follows: MS: [(+)ESI] [M+H] 604. Example 293 Synthesis of N-(3-Fluorobenzenesulfonyl)-L-prolyl-L-4-(N,JV- dimethylcarbanyloxy)phenylalanine The title compound was prepared from the product of Example 166 using the procedure described in Method 11, mp. 82-83°C. Example 294 Synthesis of N-(Toluene-4-sulfonyl)-L-prolyl-L-4-[N-methyI-Λ 7 -(2-(N , -methyl-iV- toluenesulfonyl-amino)ethyl)carbamyloxy]phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (DMSO-cL,, 400 MHz): δ 8.27 (d, IH); 7.71 (d, 2H); 7.69 (d, 2H); 7.40 (m, 4H); 7.24 (d, 2H); 6.99 (d, 2H); 4.86 (m, IH); 4.43 (m, IH); 4.06 (m, IH); 3.51 (m, IH); 3.2 - 3.35 (m, 3H); 2.9 - 3.2 (overlapping m, 7H); 2.67 (d, 3H); 2.38 (s, 6H); 1.60 (m, 3H); 1.40 (m, IH); 1.20 (d, 3H); 1.15 (d, 3H). IR (KBr, cm 1 ) 3400, 2975, 2950, 1725, 1680, 1510, 1450, 1400, 1280, 1225, 1150, 1110, 800, 730, 675, 575, 550. MS ((+)ESI, m/z (%)) 760 (100 [M+NH + ). Anal. Calcd. for C 36 H 46 N 4 O 9 S 2 : C, 58.20; H, 6.24; N, 7.54. Found: C, 57.90; H, 6.30; N, 7.34. Example 295 Synthesis of N-(Toluene-4-sulfony.)-L-prolyl-L-4-[N-(2-(iV- phenylaminocarbonyloxy)ethyl)carbamyloxy)]phenylalanine Isopropyl Ester The title compound was prepared following the procedure described for the preparation of Example 4 and substimtion of appropriate starting materials. NMR data was as follows: Η NMR (DMSO , 400 MHz): δ 9.67 (s, IH); 8.27 (d, IH); 7.72 (d, 2H); 7.47 (d, 2H); 7.42 (d, 2H); 7.24 (m, 4H); 6.98 (m, 3H); 4.87 (m, lh); 4.45 (m, IH); 4.18 (m, 2H); 4.05 (m, IH); 3.4 (m, 3H); 3.05 (m, 3H) 2.40 (s, 3H); 1.6 (m, 3H); 1.40 (m, IH); 1.2 (d, 3H); 1.15 (d, 3H). IR (KBr, cm 1 ) 3350, 2950, 1725, 1675, 1600, 1550, 1500, 1325, 1200, 1150, 1100, 650, 575, 525. MS ((+)ESI, m/z (%)) 698 (100 [M+NHJ + ). Anal. Calcd. for C 34 H 40 N 4 O 9 S.0.21 EtOAc. 0.5H 2 O: C, 59.08; H, 6.07; N, 7.91. Found: C, 59.08; H, 6.02; N, 7.80. Example 296 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-4-(frans-hydroxy)prolyl-L-4-(N,N- dimethyIcarbamyloxy)phenylalanine Isopropyl Ester The title compound was prepared following the procedure described in Example 2 and substimtion of appropriate starting materials. Physical data was as follows: MS: [(+)ESI], [M+NH 4 ] 583. Example 297 Synthesis of N-(4-Fluorobenzenesulfonyl)-L-4-(^rα«5-hydroxy)prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-Butyl Ester The title compound was prepared following the procedure described in Example 2 and substimtion of appropriate starting materials. Physical data was as follows: MS: [(+)ESrj, [M+NH 597. Example 298 Synthesis of N-(4-Amidinobenzenesulfonyl)-L-prolyI-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The title compound was prepared from the product of Example 288 using the procedure described in Method 5, mp.l30-132°C. Example 299 Synthesis of Piperazine-1 ,4-dicarboxylic Acid Bis-{4-[(2S)-2-tert-butoxycarbonyl-2- ((4R)-5,5-dimethyl-3-(toluene-4-sulfonyl)thiazolidine-4- carboxamido)ethyI]phenyl} Ester The title compound was prepared following the procedure described in Example 4, except that 0.5 equivalents of piperazine were used. Physical data was as follows: Anal. Calcd. for C 58 H 74 N 6 O 14 S 4 : C, 57.69; H, 6.18; N, 6.96. Found: C, 58.01; H, 6.07; N, 6.68. Example 300 Synthesis of Piperazine-1 ,4-dicarboxylic Acid Bis-{4-[(2S)-2-carboxy-2-((4R)-5,5- dimethyl-3-(toluene-4-sulfonyl)thiazolidine-4-carboxamido)ethyl]phenyl} Ester The title compound was prepared by hydrolysis of the di-t-butyl ester from Example 299 with formic acid to give a white foam (300 mg, quantitative). Physical data was as follows: Anal. Calcd. for C 50 H 58 N 6 O 14 S 4 : C, 54.83; H, 5.34; N, 7.67 Found: C, 55.10; H, 5.57; N, 7.37. Other compounds prepared by the methods described above include those set forth in Examples 301-373 in Tables III A and IIIB below. Table IIIA LU »1 σs ) O t o t t L t L t to to σs to ^4 L>J t 00 > to VO In addition, Examples 319, 324, 325, 332, 333, 334, 335 and 349 in Table III A are exemplified as follows: Example 319 Synthesis of N-(Toluene-4-sulfonyl)-L-(4-hydroxy)proIyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine The starting N-(toluene-4-sulfonyl)-L-(4-hydroxy)prolyl-L-4-(4- methy lpiperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester (300 mg) was dissolved in formic acid (15 mL). The reaction was stirred at room temperamre for 72 hours. The solvent was evaporated and the residue was purified using HPLC, reverse phase, 20-80% CH 3 CΝ/water. At a retention time of 10.75 minutes, 82 mg of the title compound was obtained, mp: 128- 130°C. Example 324 Synthesis of N-(Toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine The starting N-(toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(thiomoφholin- 4-ylcarbonyloxy)phenylalanine tert-butyl ester (130 mg) was dissolved in formic acid (7 mL). The reaction was stirred at room temperamre for 6 hours. The solvent was evaporated in vacuo to give 150 mg of the desired product, mp: 111-112°C. Example 325 Synthesis of N-(Toluene-4-sulfonyl)-L-(4-oxo)prolyI-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine The starting N-(toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(4- methylpiperazin-1 -ylcarbonyloxy )phenylalanine tert-butyl ester (150 mg) was dissolved in formic acid (7 mL). The reaction was stirred at room temperamre for 6 hours. The solvent was evaporated in vacuo, and the residue was purified using HPLC, reverse phase, 20-80% CH 3 CH/ water. The retention time was 10.34 minutes. The product was freeze dried to yield 82 mg of the title compound, mp: 99-101 °C. Example 332 Synthesis of N-(Toluene-4-sulfonyl)-L-(4-methanesulfonyloxy)prolyl-L-4-(7VyV- dimethylcarbamyloxy)phenylaIanine tert-Butyl Ester The starting N-(toluene-4-sulfonyl)-L-(4-hydroxy)prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester (300 mg) and methylsulfonyl chloride was dissolved in THF (7 mL) at 0°C in an ice bath. Triethylamine (0.21 mL) was added. The ice bath was removed after 10 minutes. The reaction mixmre was stirred at room temperamre for 24 hours. Ethyl acetate (20 mL) as added. The mixmre was washed with citric acid (5%, 20 mL, 2x), and washed with samrated ΝaHCO, solution (20 mL), then with brine. The solution was dried over MgSO 4 . The solvent was evaporated, and the residue was flushed on a silica gel column. The solvent was evaporated in vacuo to give 300 mg of the desired product, mp: 73- 74°C. Example 333 Synthesis of N-(4-AminobenzenesulfonyI)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The starting N-(4-aminobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine methyl ester (300 mg) and LiOH solution (2M, 0.6 mL) were added to methanol (6 mL). The reaction was stirred at room temperamre for 7 hours. The solvent was evaporated in vacuo, and the residue was purified using HPLC, reverse phase, 20-80% CH 3 CN/water. At a retention time of 12.11 minutes, 27 mg of the desired product were obtained , mp: 130-132°C. Example 334 Synthesis of N-(4-Aminocarbonylbenzenesulfonyl)-L-prolyl-L-4-(thiomorphoIin-4- ylcarbonyloxy)phenylalanine The starting N-(4-aminocarbonylbenzenesulfonyl)-L-prolyl-L-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine methyl ester (300 mg) and LiOH solution (2M, 0.5 mL) were added to methanol (6 mL). The reaction was stirred at room temperamre for 8 hours. The solvent was evaporated in vacuo, and the residue purified using HPLC, reverse phase, 20-80% CH 3 CΝ/water. At a retention time of 12.69 minutes, 20 mg of the desired product was obtained, mp: 123-125 °C. Example 335 Synthesis of N-(4-AmidinobenzenesuIfonyl)-L-prolyI-L-4-(thiomorpholin-4- ylcarbonyloxy)phenylalanine The starting N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin- 4-ylcarbonyloxy)phenylalanine methyl ester (300 mg) and LiOH solution (2M, 0.5 mL) were added to methanol (6 mL). The reaction was stirred at room temperamre for 8 hours. The solvent was evaporated in vacuo, and the residue was purified using HPLC, reverse phase, 20-80% CH 3 CΝ/water. At a retention time of 11.78 minutes, 25 mg of the desired product were obtained, mp: 123-125 °C. Example 349 Synthesis of N-(Toluene-4-sulfonyl)-L-(4-methanesulfonyloxy)prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine The starting N-(toluene-4-sulfonyl)-L-(4-methanesulfonyloxy)prolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester (200 mg) was dissolved in formic acid (5 mL). The reaction mixmre was stirred at room temperamre for 6 hours. The solvent was evaporated in vacuo to provide the desired product (195 mg), mp: 83-84°C. Example A In vitro Assay For Determining Binding of Candidate Compounds to VLA-4 An in vitro assay was used to assess binding of candidate compounds to a 4 P[ integrin. Compounds which bind in this assay can be used to assess VCAM-1 levels in biological samples by conventional assays (e.g., competitive binding assays). This assay is sensitive to I 0 values as low as about 1 nM. The activity of a λ integrin was measured by the interaction of soluble VCAM-1 with Jurkat cells (e.g. , American Type Culture Collection Νos. TIB 152, TIB 153, and CRL 8163), a human T-cell line which expresses high levels of α 4 β, integrin. VCAM-1 interacts with the cell surface in an a 4 Pj integrin-dependent fashion (Yednock, et al. J. Bio. Chem., 1995, 270:28740). Recombinant soluble VCAM-1 was expressed as a chimeric fusion protein containing the seven extracellular domains of VCAM-1 on the Ν- terminus and the human IgGj heavy chain constant region on the C-terminus. The VCAM-1 fusion protein was made and purified by the manner described by Yednock, supra. Jurkat cells were grown in RPMI 1640 supplemented with 10% fetal bovine serum, penicillin, streptomycin and glutamine as described by Yednock, supra. Jurkat cells were incubated with 1.5 mM MnCl 2 and 5 μg/mL 15/7 antibody for 30 minutes on ice. Mn +2 activates the receptor to enhance ligand binding, and 15/7 is a monoclonal antibody that recognizes an activated/ligand occupied conformation of α 4 β, integrin and locks the molecule into this conformation thereby stabilizing the integrin interaction. Yednock, et al. , supra. Antibodies similar to the 15/7 antibody have been prepared by other investigators (Luque, et al, 1996, J. Bio. Chem. 271:11067) and may be used in this assay. Cells were then incubated for 30 minutes at room temperamre with candidate compounds, in various concentrations ranging from 66 μg/mL to 0.01 μg/mL using a standard 5-point serial dilution. 15 μL soluble recombinant VCAM-1 fusion protein was then added to Jurkat cells and incubated for 30 minutes on ice. (Yednock et al., supra.). Cells were then washed two times and resuspended in PE-conjugated goat F(ab') 2 anti-mouse IgG Fc (Immunotech, Westbrook, ME) at 1:200 and incubated on ice, in the dark, for 30 minutes. Cells were washed twice and analyzed with a standard fluorescence activated cell sorter ("FACS") analysis as described in Yednock, et al., supra. Compounds having an IC 50 of less than about 15 μM possess binding affinity to α 4 βι. When tested in this assay, each of the compounds of Examples 1-373 (or the corresponding carboxylic acids of the ester compounds, i.e. the prodrugs) has an IC 50 of 15 μM or less. Example B In vitro Saturation Assay For Determining Binding of Candidate Compounds to α 4 β ι The following describes an in vitro assay to determine the plasma levels needed for a compound to be active in the Experimental Autoimmune Encephalomyelitis ("EAE") model, described in the next example, or in other in vivo models. Log-growth Jurkat cells are washed and resuspended in normal animal plasma containing 20 μg/ml of the 15/7 antibody (described in the above example). The Jurkat cells are diluted two-fold into either normal plasma samples containing known candidate compound amounts in various concentrations ranging from 66 μg/mL to 0.01 μg/mL, using a standard 12 point serial dilution for a standard curve, or into plasma samples obtained from the peripheral blood of candidate compound-treated animals. Cells are then incubated for 30 minutes at room temperamre, washed twice with phosphate-buffered saline ("PBS") containing 2% fetal bovine serum and ImM each of calcium chloride and magnesium chloride (assay medium) to remove unbound 15/7 antibody. The cells are then exposed to phycoerythrin-conjugated goat F(ab') 2 anti- mouse IgG Fc (Immunotech, Westbrook, ME), which has been adsorbed for any non-specific cross-reactivity by co-incubation with 5 % serum from the animal species being studied, at 1:200 and incubated in the dark at 4°C for 30 minutes. Cells are washed twice with assay medium and resuspended in the same. They are then analyzed with a standard fluorescence activated cell sorter ("FACS") analysis as described in Yednock et al. J. Bio. Chem. , 1995, 270:28740. The data is then graphed as fluorescence versus dose, e.g., in a normal dose-response fashion. The dose levels that result in the upper plateau of the curve represent the levels needed to obtain efficacy in an in vivo model. This assay may also be used to determine the plasma levels needed to samrate the binding sites of other integrins, such as the o^β, integrin, which is the integrin most closely related (Palmer et al, 1993, J. Cell Bio., 123: 1289). Such binding is predictive of in vivo utility for inflammatory conditions mediated by a , integrin, including by way of example, airway hyper-responsiveness and occlusion that occurs with chronic asthma, smooth muscle cell proliferation in atherosclerosis, vascular occlusion following angioplasty, fibrosis and glomerular scarring as a result of renal disease, aortic stenosis, hypertrophy of synovial membranes in rheumatoid arthritis, and inflammation and scarring that occur with the progression of ulcerative colitis and Crohn' s disease. Accordingly, the above-described assay may be performed with a human colon carcinoma cell line, SW 480 (ATTC #CCL228) transfected with cDNA encoding 9 integrin (Yokosaki et al., 1994, J. Bio. Chem., 269:26691), in place of the Jurkat cells, to measure the binding of the ocgβ. integrin. As a control, SW 480 cells which express other α and β; subunits may be used. Using this assay, the plasma levels necessary to obtain efficacy in in vivo models for and α 9 β, have been established for compounds of formula I tested in this assay. Accordingly, another aspect of this invention is directed to a method for treating a disease in a mammalian patient, which disease is mediated by α^, and which method comprises administering to said patient a therapeutically effective amount of a compound of this invention. Such compounds are preferably administered in a pharmaceutical composition described herein above. Effective daily dosing will depend upon the age, weight, condition of the patient which factors can be readily ascertained by the attending clinician. However, in a preferred embodiment, the compounds are administered from about 20 to 500 μg/kg per day. Example C In vivo Evaluation The standard multiple sclerosis model, Experimental Autoimmune (or Allergic) Encephalomyelitis ("EAE"), was used to determine the effect of candidate compounds to reduce motor impairment in rats or guinea pigs. Reduction in motor impairment is based on blocking adhesion between leukocytes and the endothelium and correlates with anti-inflammatory activity in the candidate compound. This model has been previously described by Keszthelyi et al., Neurology, 1996, 47:1053-1059, and measures the delay of onset of disease. Brains and spinal cords of adult Hartley guinea pigs were homogenized in an equal volume of phosphate-buffered saline. An equal volume of Freund's complete adjuvant (100 mg mycobacterium tuberculosis plus 10 ml Freund's incomplete adjuvant) was added to the homogenate. The mixture was emulsified by circulating it repeatedly through a 20 ml syringe with a peristaltic pump for about 20 minutes. Female Lewis rats (2-3 months old, 170-220 g) or Hartley guinea pigs (20 day old, 180-200 g) were anesthetized with isoflurane and three injections of the emulsion, 0.1 ml each, were made in each flank. Motor impairment onset is seen in approximately 9 days. Candidate compound treatment began on Day 8, just before onset of symptoms. Compounds were administered subcutaneously ("SC"), orally ("PO") or intraperitoneally ("IP"). Doses were given in a range of lOmg/kg to 200 mg/kg, bid, for five days, with typical dosing of 10 to 100 mg/kg SC, 10 to 50 mg/kg PO, and 10 to 100 mg/kg IP. Antibody GG5/3 against α^ integrin (Keszthelyi et al., Neurology, 1996, 47: 1053-1059), which delays the onset of symptoms, was used as a positive control and was injected subcutaneously at 3 mg/kg on Day 8 and 11. Body weight and motor impairment were measured daily. Motor impairment was rated with the following clinical score: 0 no change 1 tail weakness or paralysis 2 hindlimb weakness 3 hindlimb paralysis 4 moribund or dead A candidate compound was considered active if it delayed the onset of symptoms, e.g., produced clinical scores no greater than 2 or slowed body weight loss as compared to the control. When tested in this in vivo assay, the compounds of Examples 4, 9, 11, 12, 16, 51, 66, 73, 75, 82, 95, 101, 117, 137 and other Examples were active in this assay. Example D Asthma Model Inflammatory conditions mediated by integrin include, for example, airway hyper-responsiveness and occlusion that occurs with chronic asthma. The following describes an asthma model which can be used to smdy the in vivo effects of the compounds of this invention for use in treating asthma. Following the procedures described by Abraham et al, J. Clin. Invest, 93:776-787 (1994) and Abraham et al, Am J. Respir Crit Care Med, 156:696-703 (1997), both of which are incoφorated by reference in their entirety, compounds of this invention were formulated into an aerosol and administered to sheep which are hypersensitive to Ascaris suum antigen. Compounds which decrease the early antigen-induced bronchial response and/or block the late-phase airway response, e.g., have a protective effect against antigen-induced late responses and airway hyper-responsiveness ("AHR"), are considered to be active in this model. Allergic sheep which are shown to develop both early and late bronchial responses to inhaled Ascaris suum antigen were used to smdy the airway effects of the candidate compounds. Following topical anesthesia of the nasal passages with 2% lidocaine, a balloon catheter was advanced through one nostril into the lower esophagus. The animals were then intubated with a cuffed endotracheal mbe through the other nostril with a flexible fiberoptic bronchoscope as a guide. Pleural pressure was estimated according to Abraham (1994). Aerosols (see formulation below) were generated using a disposable medical nebulizer that provides an aerosol with a mass median aerodynamic diameter of 3.2 μm as determined with an Andersen cascade impactor. The nebulizer was connected to a dosimeter system consisting of a solenoid valve and a source of compressed air (20 psi). The output of the nebulizer was directed into a plastic T-piece, one end of which was connected to the inspiratory port of a piston respirator. The solenoid valve was activated for 1 second at the beginning of the inspiratory cycle of the respirator. Aerosols were delivered at V τ of 500 mL and a rate of 20 breaths/minute. A 0.5 % sodium bicarbonate solution only was used as a control. To assess bronchial responsiveness, cumulative concentration-response curves to carbachol were generated according to Abraham (1994). Bronchial biopsies were taken prior to and following the initiation of treatment and 24 hours after antigen challenge. Bronchial biopsies were preformed according to Abraham (1994). An in vitro adhesion smdy of alveolar macrophages were also performed according to Abraham (1994), and a percentage of adherent cells was calculated. Aerosol Formulation A solution of the candidate compound in 0.5% sodium bicarbonate/saline (w/v) at a concentration of 30.0 mg/mL was prepared using the following procedure: A. Preparation of 100 mL of 0.5% Sodium Bicarbonate / Saline Stock Solution: Procedure: 1. Add 0.5 g sodium bicarbonate into a 100 mL volumetric flask. 2. Add approximately 90.0 mL saline and sonicate until dissolved. 3. Q.S. to 100.0 mL with saline and mix thoroughly. B. Preparation of 10.0 mL of 30.0 mg/mL Candidate Compound: Procedure: 1. Add 0.300 g of the candidate compound into a 10.0 mL volumetric flask. 2. Add approximately 9.7 mL of 0.5% sodium bicarbonate/saline stock solution. 3. Sonicate until the candidate compound is completely dissolved. 4. Q.S. to 10.0 mL with 0.5% sodium bicarbonate/saline stock solution and mix thoroughly. Compounds of this invention were found to be active in this model. Additionally, using a conventional oral formula, a compound of this invention was active in this model.

Claims: WHAT IS CLAIMED IS: 1. A compound of formula I: wherein R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocylic, heteroaryl and substimted heteroaryl; R 2 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, substimted cycloalkyl, cycloalkenyl, substimted cycloalkenyl, heterocyclic, substimted heterocyclic, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, and R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 can form a heterocyclic or a substimted heterocyclic group; R 3 is selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and, when R 2 does not form a heterocyclic group with R 1 , R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 can form a heterocyclic or a substimted heterocyclic group; R 5 is -(CH 2 ) X -Ar-R 5 where R 5 is selected from the group consisting of -O-Z-NR 8 R 8' and -O-Z-R 12 wherein R 8 and R 8' are independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocyclic, and where R 8 and R 8 are joined to form a heterocycle or a substimted heterocycle, R 12 is selected from the group consisting of heterocycle and substimted heterocycle, and Z is selected from the group consisting of -C(O)- and -SO 2 -, Ar is aryl, heteroaryl, substimted aryl or substimted heteroaryl, x is an integer of from 1 to 4; Q is -C(X)NR 7 - wherein R 7 is selected from the group consisting of hydrogen and alkyl; and X is selected from the group consisting of oxygen and sulfur; and pharmaceutically acceptable salts thereof. 2. A compound of formula IA: IA wherein R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocylic, heteroaryl and substimted heteroaryl; R 2 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, substimted cycloalkyl, cycloalkenyl, substimted cycloalkenyl, heterocyclic, substimted heterocyclic, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, and R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 can form a heterocyclic or a substimted heterocyclic group; R 3 is selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and, when R 2 does not form a heterocyclic group with R 1 , R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 can form a heterocyclic or a substimted heterocyclic group; R 5 is -(CH 2 ) X -Ar-R 5' and R 5' is selected from the group consisting of -O-Z-NR 8 R 8' and -O-Z-R 12 wherein R 8 and R 8' are independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocyclic, and where R 8 and R 8 are joined to form a heterocycle or a substimted heterocycle, R 12 is selected from the group consisting of heterocycle and substimted heterocycle, and Z is selected from the group consisting of -C(O)- and -SO 2 -, Ar is aryl, heteroaryl, substimted aryl or substimted heteroaryl, x is an integer of from 1 to 4; R 6 is selected from the group consisting of amino, alkoxy, substimted alkoxy, cycloalkoxy, substimted cycloalkoxy, -O-(N-succinimidyl), -NH- adamantyl, -O-cholest-5-en-3-β-yl, -NHOY where Y is hydrogen, alkyl, substimted alkyl, aryl, and substimted aryl, -NH(CH 2 ) p COOY where p is an integer of from 1 to 8 and Y is as defined above, -OdLNR^ 10 where R 9 is selected from the group consisting of -C(O)-aryl and -C(O)-substituted aryl and R 10 is selected from the group consisting of hydrogen and -CHCOOR 11 where R 11 is alkyl, and -NHSO 2 Z' where Z' is alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic and substimted heterocyclic; Q is -C(X)NR 7 - wherein R 7 is selected from the group consisting of hydrogen and alkyl; and X is selected from the group consisting of oxygen and sulfur; and pharmaceutically acceptable salts thereof with the following provisos (A) when R 1 and R 2 together with the SO 2 group pendent to R 1 and the nitrogen pendent to R 2 form a saccharin-2-yl group, R 3 is -CH 3 , R 5 is p-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; (B) when R 1 is p-methylphenyl, R 2 and R 3 together with the nitrogen atom pendent to R 2 and the carbon atom pendent to R 3 form a pyrrodinyl ring derived from D-proline; R 5 is p-[(4-methylpiperazin-l-yl)NC(O)O- ]benzyl derived from D-phenylalanine and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; (C) when R 1 is pyrimidin-2-yl, R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 form a pyrrolidinyl ring, R 5 is p-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; and (D) when R 1 is p-methylphenyl, R 2 and R 3 together with the nitrogen atom pendent to R 2 and the carbon atom pendent to R 3 form a (2S)-piperazin- 2-carbonyl ring; R 5 is p-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 . 3. A compound according to Claims 1 or 2 wherein R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heterocyclic, substimted heterocylic, heteroaryl and substimted heteroaryl. 4. A compound according to Claims 1 or 2 wherein R 1 is selected from the group consisting of methyl, isopropyl, /z-butyl, benzyl, phenethyl, phenyl, 4-methylphenyl, 4-t-butylphenyl, 2,4,6-trimethylphenyl, 2- fluorophenyl, 3 -fluorophenyl, 4-fluorophenyl, 2,4-difluorophenyl, 3,4- difluorophenyl, 3,5-difluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4- chlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 3-chloro-4- fluorophenyl, 4-bromophenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4- methoxyphenyl, 3,4-dimethoxyphenyl, 4-t-butoxyphenyl, 4-(3x dimethylamino-«-propoxy)-phenyl, 2-carboxyphenyl, 2- (methoxycarbonyl)phenyl, 4-(H 2 NC(O)-)phenyl, 4-(H 2 NC(S)-)phenyl, 4- cyanophenyl, 4-trifluoromethylphenyl, 4-trifluoromethoxyphenyl, 3,5-di- (trifluoromethyl)phenyl, 4-nitrophenyl, 4-aminophenyl, 4-(CH 3 C(O)NH- )phenyl, 4-(PhNHC(O)NH-)phenyl, 4-amidinophenyl, 4- methylamidinophenyl, 4-(CH 3 SC( = NH)-)phenyl, 4-chloro-3-(H 2 NS(O) 2 - )phenyl, 1-naphthyl, 2-naphthyl, pyridin-2-yl, pyridin-3-yl, pyrimidin-2-yl, quinolin-8-yl, 2-(trifluoroacetyl)-l ,2,3 ,4-tetrahydroisoquinolin-7-yl, moφholin-4-yl, 2-thienyl, 5-chloro-2-thienyl, 2,5-dichloro-4-thienyl, 1-N- methy limidazol-4-yl, l-N-methylpyrazol-3-yl, l-N-methylpyrazol-4-yl, 1-N- butylpyrazol-4-yl, l-N-methyl-3-methyl-5-chloropyrazol-4-yl, l-N-methyl-5- methyl-3-chloropyrazol-4-yl, 2-thiazolyl and 5-methyl-l,3,4-thiadiazol-2-yl. 5. A compound according to Claims 1 or 2 wherein R 2 is selected from the group consisting of hydrogen, methyl, phenyl, benzyl, -(CH 2 ) 2 -2- thienyl, and -(CH 2 ) 2 -φ. 6. A compound according to Claims 1 or 2 wherein R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 are joined to form a heterocyclic group or substimted heterocyclic group. 7. A compound according to Claims 1 or 2 wherein R 2 and R 3 together with the nitrogen atom bound to R 2 substiment and the carbon bound to the R 3 substiment form a heterocyclic group or a substimted heterocyclic group. 8. A compound according to Claim 7 wherein the heterocyclic group is saturated. 9. A compound according to Claim 7 wherein the heterocyclic group is selected from the group consisting of azetidinyl, thiazolidinyl, piperidinyl, piperazinyl, dihydroindolyl, tetrahydroquinolinyl, thiomoφholinyl, pyrrolidinyl, 4-hydroxypyrrolidinyl, 4-oxopyrrolidinyl, 4- fluoropyrrolidinyl, 4,4-difluoropyrrolidinyl, 4-(thiomoφholin-4-ylC(O)O- )pyrrolidinyl, 4-(CH 3 S(O) 2 O-)pyrrolidinyl, 3-phenylpyrrolidinyl, 3- thiophenylpyrrolidinyl, 4-aminopyrrolidinyl, 3-methoxypyrrolidinyl, 4,4- dimethylpyrrolidinyl, 4-N-Cbz-piperazinyl, 4-(CH 3 S(O) 2 -)piperazinyl, 5,5- dimethylthiazolindin-4-yl, 1 , 1-dioxo-thiazolidinyl, 1 , 1 -dioxo-5 ,5- dimethylthiazolidin-2-yl and 1,1-dioxothiomoφholinyl. 10. A compound according to Claims 1 or 2 wherein R 3 is selected from the group consisting of methyl, phenyl, benzyl, diphenylmethyl, -CH 2 CH 2 -COOH, -CH 2 -COOH, 2-amidoethyl, /sσ-butyl, t-butyl, -CH 2 O-benzyl and hydroxymethyl. 11. A compound according to Claims 1 or 2 wherein Q is -C(O)NH- or -C(S)NH-. 12. A compound according to Claims 1 or 2 wherein Ar is aryl or substimted aryl. 13. A compound according to Claim 12 wherein Ar is phenyl or substituted phenyl and x is 1. 14. A compound according to Claim 1 or 2 wherein R 5 is selected from the group consisting of 3-[(CH 3 ) 2 NC(O)O-]benzyl, 4-[(CH 3 ) 2 NC(O)O-]benzyl, 4-[(CH 3 ) 2 NS(O) 2 O-]benzyl, 4-[(piperidin-l Xyl)C(O)O-]benzyl, 4-[(piperidin-4Xyl)C(O)O-]benzyl, 4-[(r-methylpiperidin-4 X yl)C(O)O-]benzyl, 4- [(4 ' -hydroxypiperidin- 1 ' -yl)C(O)O-]benzyl , 4-[(4Xformyloxypiperidin-l X yl)C(O)O-]benzyl, 4-[(4Xethoxycarbonylpiperidin-l X yl)C(O)O-]benzyl, 4-[(4 X carboxylpiperidin- -yl)C(O)O-]benzyl, 4-[(3 Xhydroxymethylpiperidin-1 '-yl)C(O)O-]benzyl, -[(4Xhydroxymethylpiperidin- -yl)C(O)O-]benzyl, -[(4 ' -phenyl- 1 XBoc-piperidin-4 ' -y l)-C(O)O-]benzyl , -[(4Xpiperidon-r-yl ethylene ketal)C(O)O-]benzyl, -[(piperazin-4Xyl)-C(O)O-]benzyl, -[(l X Boc-piperazin-4 X yl)-C(O)O-]benzyl, -[(4Xmethylpiperazin-l '-yl)C(O)O-]benzyl, - [(4 ' -methy lhomopiperazin- 1 ' -yl)C(O)O-]benzyl , -[(4 x(2-hydroxyethy Opiperazin- 1 X yl)C(O)O-]benzyl , -[(4Xphenylpiperazin-r-yl)C(O)O-]benzyl, -[(4 X (pyridin-2-yl)piperazin-l X yl)C(O)O-]benzyl, -[(4 X (4-trifluoromethylpyridin-2-yl)piperazin-l X yl)C(O)O-]benzyl, -[(4'-(pyrimidin-2-yl)piperazin- -yl)C(O)O-]benzyl, -[(4 X acetylpiperazin- -yl)C(O)O-]benzyl, -[(4 X (phenylC(O)-)piperazin-l'-yl)C(O)O-]benzyl, -[(4X(pyridin-4-ylC(O)-)piperazin-l Xyl)C(O)O-]benzyl, -[(4X(phenylNHC(O)-)piperazin-l '-yl)C(O)O-]benzyl, -[(4'-(phenylNHC(S)-)piperazin-r-yl)C(O)O-]benzyl, - [(4 ' -methanesulfony lpiperazin- 1 ' -y l-C(O)O-)benzy 1 , -[(4 ' -trifluoromethanesulf ony lpiperazin- 1 ' -yl-C(O)O-)benzyl , -[(moφholin-4'-yl)C(O)O-]benzyl, -nitro-4-[(moφholin-4 X yl)-C(O)O-]benzyl, -[(thiomoφholin-4 X yl)C(O)O-]benzyl , -[(thiomoφholin-4 X yl sulfone)-C(O)O-]benzyl, -[(pyrrolidin-l '-yl)C(O)O-]benzyl, -[(2Xmethylpyrrolidin-l Xyl)C(O)O-]benzyl, -[(2 X (methoxycarbony0pyrrolidin- -yl)C(O)O-]benzyl, -[(2 X (hydroxymethyl)pyrrolidin-r-yl)C(O)O-]benzyl, -[(2 X (N,N-dimethylamino)ethyl)(CH 3 )NC(O)O-]benzyl, -[(2 X (N-methyl-N-toluene-4-sulfonylamino)ethyl)(CH 3 )N- C(O)O-]benzyl, -[(2X(moφholin-4 X yl)ethyl)(CH 3 )NC(O)O-]benzyl, 4-[(2'-(hydroxy)ethyl)(CH 3 )NC(O)O-]benzyl, 4-[bis(2X(hydroxy)ethyl)NC(O)O-]benzyl, 4-[(2X(formyloxy)ethyl)(CH 3 )NC(O)O-]benzyl, 4-[(CH 3 OC(O)CH 2 )HNC(O)O-]benzyl, 4-[2X(phenylNHC(O)O-)ethyl-]HNC(O)O-]benzyl, 3-chloro-4-[(CH 3 ) 2 NC(O)O-]benzyl, 3-chloro-4-[(4Xmethylpiperazin-lXyl)C(O)O-]benzyl, 3-chloro-4-[(4X(ρyridin-2-yl)piperazin-r-yl)C(O)O-]benzyl, 3-chloro-4- [(thiomoφholin-4 ' -yl)C(O)O-]benzy 1 , and 3-fluoro-4-[(CH 3 ) 2 NC(O)O-]benzyl. 15. A compound according to Claim 2 wherein R 6 is selected from the group consisting of 2,4-dioxo-tetrahydrofuran-3-yl (3,4-enol), methoxy, ethoxy, /t-propoxy, isopropoxy, n-butoxy, t-butoxy, cyclopentoxy, cyclopropylmethoxy, neopentoxy, 2-α-isopropyl-4-β-methylcyclohexoxy, 2- β-isopropyl-4-β-methylcyclohexoxy , 2-methoxyphenoxy , 2-(moφholin-4- yl)ethoxy, -O(CH 2 CH 2 O) 2 CH 3 , 2-(phenoxy)ethoxy, -OCH 2 C(CH 3 ) 2 NHBoc, -NH 2 , benzyloxy, -NHCH 2 COOH, -NHCH 2 CH 2 COOH, -NH-adamantyl, -NHSO 2 -p-CH 3 -φ, -NHCH 2 CH 2 COOCH 2 CH 3 , -NHOY' where Y' is hydrogen, methyl, wo-propyl or benzyl, -O-(N-succinimidyl), -O-cholest-5- en-3-β-yl, -OCH 2 -OC(O)C(CH 3 ) 3 , -O(CH 2 ) z NHC(O)W where z is 1 or 2 and W is selected from the group consisting of pyrid-3-yl, N-methylpyridyl, and N-methyl- l,4-dihydro-pyrid-3-yl, -NR"C(O)-R' where R' is aryl, heteroaryl or heterocyclic and R" is hydrogen or -CH 2 C(O)OCH 2 CH 3 . 16. A compound selected from the group consisting of: N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine n-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine cyclopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine n-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine cyclopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(isonipecotoyloxy)phenylalanine ethyl ester N-(α-toluenesulfonyl)-L-prolyl-L-4-(N- methylisonipecotoyloxy)phenylalanine ethyl ester N-(α-toluenesulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine N-(tomene-4-sulfonyl)-L-prolyl-L-3-(N,N- dimethylcarbamyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(l-tert-butylcarbonyloxy-4- phenylpiperidin-4-ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimefhylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-[(l , l-dioxo)thiamoφholin-3 -carbony l]-L-4- (N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L- [(1,1 -dioxo)thiamoφholin-3 -carbony l]-L-4- (N,N-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4- methy lpiperazin- l-ylcarbonyloxy)pheny lalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4- methy lpiperazin- 1 -ylcarbony loxy )phenylalanine N-(toluene-4-sulfonyl)sarcosyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine N-( 1 -methylimidazole-4-sulfonyl)-L-proly l-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-aminobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(α-toluenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(piperazin-2-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-( -toluenesulfonyl)-L-(5 ,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-adamantyl amide N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanylglycine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine methyl ester N-(toluene-4-sulfonyl)-L-(piperazin-2-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(4-benzyloxycarbonylpiperazin-2-carbonyl)-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(isonipecotoyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-[(l , l-dioxo)thiamoφholin-3-carbonyl]-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-[(l,l-dioxo)thiamoφholin-3-carbonyl]-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine N-( 1 -methy lpyrazole-4-sulfony l)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulf ony l)sarcosyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l , l-dioxo-5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-( 1 -methy lpyrazole-4-sulf ony l)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine 2-(saccharin-2-yl)propionoyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l , l-dioxo-5 ,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(pyridine-3-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-D-prolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(4-methylpiρerazin-l- ylcarbonyloxy )phenylalanine tert-butyl ester N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-[(l , l-dioxo)thiamoφholin-3-carbonyl]-L-4- (N,N-dimethylaminosulfonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbony loxy )pheny lalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(isonipecotoyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(pyrrolidin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine neopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine neopentyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-tert-butyloxycarbonylpiperazin-l- ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine ethyl ester 2-(saccharin-2-y Opropionoy l-L-4-(4-methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester 2-(saccharin-2-yl)propionoyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)sarcosyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)sarcosyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-N-methylalanyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(pyridine-3-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(pyrimidine-2-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-nitrobenzenesulfonyl)-L-proly l-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-( 1 ,1 -dioxothiamoφholin-3 -carbony l)-L-4-(N,N- dimethylaminosulfonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-( 1 -methylimidazole-4-sulfony l)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfony l)-L-proly l-L-4-(piperazin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-proly l-L-4-( 1 -tert-butyloxycarbony lpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(piperazin- 1 - ylcarbonyloxy )phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-acety lpiperazin- 1 - ylcarbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-methanesulfonylpiperazin-l- ylcarbonyloxy )phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(moφholin-4-ylcarbonyloxy)-3- nitrophenylalanine N-(toluene-4-sulfony l)-L-prolyl-L-4-( 1 -tert-butyloxycarbony lpiperazin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-N-methyl-2-(tert-butyl)glycinyl-L-4-(4- methy lpiperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3-carbonyl)-L- 4-( 1 , 1 -dioxothiomoφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l , l-dioxothiamoφholin-3-carbonyl)-L-4-(l , 1- dioxothiomoφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(l,l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(moφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L- 4-(moφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-trifluoromethoxybenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester 3-[N-(toluene-4-sulfonyl)-N-methylamino]-l-[l-tert-butyloxycarbonyl-2- (N,N-dimethylcarbamyloxy)phenylethyl]azetidine N-(4-fluorobenzenesulfonyl)-L-(l , l-dioxo-5 ,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-( 1 , 1 -dioxo-5 , 5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(l , l-dioxothiamoφholin-3-carbonyl)-L-4- (moφholin-4-ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(pyrimidine-2-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4-(4- methy lpiperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester 3-[N-(toluene-4-sulfonyl)-N-methylamino]-l-[l-carboxy-2-(N,N- dimethylcarbamyloxy)phenylethyl]azetidine N-(l -methy lpyrazole-4-sulfonyl)-L-prolyl-L-4-(4-methy lpiperazin- 1- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(isonipecotoyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(l , l-dioxothiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(pyrrolidin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(l , l-dioxo)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2,5-dichlorothiophene-3-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-acetamidobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-tert-butylbenzenesulfonyl)-L-(l , l-dioxothiamoφholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(pyridine-2-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(2-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2,4-difluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-acetamidobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-trifluoromethoxybenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(3,3-dimethyl)prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(3 , 3-dimethyl)prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-( 1 -methy lpyrazole-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine wo-propyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l,4-dioxa-8-aza- spiro[4.5]decan-8-yl)carbonyloxy)phenylalanine ethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(l ,4-dioxa-8-aza- spiro[4.5]decan-8-yl)carbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -acety lpiperazin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfony l)-L-proly l-L-4-(4 X methanesulfony lpiperazin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-proly l-L-4-(4 xpheny lpiperazin- 1 - ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(piperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester 2-(saccharin-2-yl)propionyl-L-4-(4 ' -methy lpiperazin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -methanesulfony lpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine (N -tert-butoxycarbonyl-2-amino-2- methylpropyl) ester N-(toluene-4-sulf ony l)-L-proly l-L-4-(4 ' -acety lpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 -hydroxypiperidin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -(moφholin-4x yl)ethyl)carbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-proly l-L-4-(N-( 1 ,4-dioxa-8-aza- spiro[4.5]decan-8-yl)carbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -hydroxyethyl)-N- methylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfony l)-L-prolyl-4-(4 x(2-hydroxyethy Opiperazin- 1 - ylcarbonyloxy)-L-phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -formyloxyethyl)-N- methylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(2 ' -hydroxy ethyl)-N- methylcarbamyloxy)phenylalanine isopropyl ester N-(toulene-4-sulfonyl)-L-prolyl-L-4-(N- (methoxycarbonylmethyl)carbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(4-N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4Xmethoxypiperidin-l- ylcarbonyloxy )phenylalanine isopropyl ester N-(toluene-4-sulfony l)-L-prolyl-L-4-(4 ' -methoxypiperidin- 1 - ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-tra w-4-hydroxyprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(moφholino-sulfonyl)-L-prolyl-L-(4-NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(moφholino-sulfonyl)-L-prolyl-L-(4-NN- dimethylcarbamyloxy)phenylalanine N-( 1 -methy lpyrazole-4-sulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(2,4-difluorobenzenesulfonyl)-L-( 1,1 -dioxothiamoφholin-3 -carbony 1)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl-thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-fluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-( 1 -methy lpyrazole-4-sulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 -carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(4-tert-butylbenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 -carbony 1)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-(3,3-dimethyl)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(2,5-dichlorothiophene-3-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-methoxybenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-methoxybenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(l-oxo-thiomoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(l-oxo-thiomoφholin-3 -carbony l)-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-difluorobenzenesulfonyl)-L-prolyl-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3 ,4-difluorobenzenesulfonyl)-L-prolyl-4-(NN- dimethylcarbamyloxy)phenylalanine N-(3,4-difluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-difluorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(thiomoφholin-4- ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine ethyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(pyridine-2-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(pyridine-2-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(pyridine-2-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(pyridine-2-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,5-difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2,4-difluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2-chlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-dichlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,5-dichlorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3 -chlorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 -carbonyl)-L-4- (NN-dimethylcarbamyloxy)pheny lalanine tert-butyl ester N-(3,4-dichlorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3-methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2-methoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-dimethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2,4-difluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(3,4-dichlorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)- L-4-(NN-dimethylcarbamyloxy)phenylalanine N-(3-chlorobenzenesulfonyl)-L-(l,l-dioxothiamoφholin-3-carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(3 -chloro-4-fluorobenzenesulfonyl)-L-( 1 , 1 -dioxothiamoφholin-3 - carbony l)-L-4-(N N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3,4-difluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thioprolyl-L-(thiomoφholin-4- ylcarbonyloxy)phenylalanine isopropyl ester N-(3,4-difluorobenzenesulfonyl)-L-(thiamoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(2,5-dichlorothiophene-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine isopropyl ester N-(8-quinolinesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(8-quinolinesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(8-quinolinesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isoproplyl ester N-(8-quinolinesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylpiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4 ' -(ethoxy carbony l)piperidin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(3-sulfonamido-4-chloro-benzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(l-oxothiomoφholin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(2,4-difluorobenzenefulfonyl)-L-(l-oxothiomoφholin-3-carbonyl)-L- 4-(N,N-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamy loxy )pheny lalanine 2,2-dimefhylpropyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2,2-dimefhylpropyl ester N-( 1 -methy lpyrazole-4-sulfonyl)-L-(5 , 5-dimethyl)thiaprolyl-L-4-(N N- dimethylcarbamyloxy)phenylalanine cyclopropylmethyl ester N-( 1 -methy lpyrazole-4-sulfonyl)-L-(5 , 5-dimethy l)thiaprolyl-L-4-(N N- dimethylcarbamyloxy)phenylalanine methyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N ) N- dimethylcarbamyloxy)phenylalanine ethyl ester N-(pyridine-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine cyclopropylmethyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2-methoxyphenyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine «-butyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine «-propyl ester N-(l-methylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2 ,2-dimethylpropionyloxymethyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-(4'-(2X aminoethyl)moφholino)carbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-[4-(carboxy)piperidin-l- ylcarbonyloxy]phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(NN-bis-(2- hydroxyethyl)carbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-[3-(hydroxymethyl)piperidin-l- ylcarbonyloxyjphenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4- trifluoromethanesulfony lpiperazin- 1 -ylcarbony loxy )phenylalanine tert- butyl ester N-(4-(N-phenylurea)benzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(2-trifluoroacetyl-l,2,3,4-tetrahydroisoquinolin-7-sulfonyl)-L-prolyl- L-4-(NN-dimethylcarbamy loxy )pheny lalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethy lcarbamyloxy)phenylalanine N-(pyridine-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(pyridine-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-methyl-Ν-(2- dimethylaminoethyl)carbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(5 , 5 -dimethy l)thiapropyl-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(N-methyl-N-(2- dimethylaminoethyl)carbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- methylpiperazin-l-ylcarbonyloxy)pheny lalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (NN-dimethycarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4- (NN-dimethylcarbamyloxy)]phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- methylpiperazin-1 -ylcarbony loxy)]phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-3-chloro-4-(N,N- dimethylcarbamyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfony0-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- (2 X pyridyl)-piperazin-l-ylcarbonyloxy)]pheny lalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- (2 ' -pyridyl)-piperazin- 1 -ylcarbonyloxy)]pheny lalanine tert-butyl ester N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-aminobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylcarbamylpiperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-phenylcarbamylpiperazin-l- ylcarbonyloxy)phenylalanine N-(l- z-butylpyrazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(pyridin-4-ylcarbonyl)piperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(Ν , N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-trαn5-4-hydroxyprolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-aminobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-[3-(hydroxymethyl)piperidin-l- ylcarbonyloxy]phenylalanine N-(toluene-4-sulfonyl)-L-(4 ,4-difluoro)prolyl-L-4-(N, N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-(4 ,4-difluoro)prolyl-L-4-(N, N- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-(4-benzoy lpiperazin- 1 - ylcarbonyloxy)phenylalanine isopropyl ester N-( 1 -methyl- lH-imidazole-4-sulfonyl)-L-prolyl-L-4-(N, N- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-4-(thiomoφholin-4-ylcarbonyloxy)prolyl-L-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine N-(4-cyanobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine isopropyl ester N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbamyloxy)phenylalanine methyl ester N-(toluene-4-sulfonyl)-L-4-oxoprolyl-L-4-(thiomoφholin-4- ylcarbony loxy )pheny lalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-4-hydroxyprolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-proly l-L-(4-benzoy lpiperazin- 1- ylcarbonyloxy)phenylalanine N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine methyl ester N-(3-fluorobenzenesulfonyl)-L-prolyl-L-4-(N,N- dimethylcarbanyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-[N-methyl-N-(2-(N-methyl-N- toluenesulfonyl-amino)ethyl)carbamyloxy]phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-[N-(2-(N- phenylaminocarbonyloxy)ethyl)carbamyloxy)]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-4-(trø>w-hydroxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-4-(tra/w-hydroxy)prolyl-L-4-(N,N- dimethylcarbamyloxy)pheny lalanine tert-butyl ester N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine piperazine- 1 ,4-dicarboxy lie acid bis-{4-[(2S)-2-tert-butoxycarbonyl-2- ((4R)-5,5-dimethyl-3-(toluene-4-sulfonyl)thiazolidine-4- carboxamido)ethyl]phenyl} ester piperazine- 1 ,4-dicarboxylic acid bis-{4-[(2S)-2-carboxy-2-((4R)-5,5- dimethyl-3-(toluene-4-sulfonyl)thiazolidine-4-carboxamido)ethyl]phenyl} ester N-(toluene-4-sulfonyl)-L-(pyrazin-3-carbonyl)-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(2- hydroxymethylpyrrolidin-1 -ylcarbonyloxy )phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(2- hydroxymethylpyrrolidin- 1 -ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(2-methoxycarbonylpyrrolidin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5 ,5 -dimethyl)thiaprolyl-L-3 -chloro-4- (thiomoφholin-4-ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy )]phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l-ylcarbonyloxy)]phenylalanine tert-butyl ester piperazine- 1 ,4-dicarboxylic acid bis-{4-[(2S)-2-isopropoxycarbonyl-2- ((2R)- 1 -(toluene-4-sulfonyl)pyrrolidine-2-carboxamido)ethyl]phenyl} ester N-(toluene-4-sulfonyl)-L-(4-hydroxy)prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2-(2-methoxyethoxy)ethyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyrimidyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-fluoro-4- (NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(toluene-4-sulfonyl)-L-( 1 -methanesulfony lpyrazin-3 -carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-[2-( 1 , 1 -dioxo-2,3 -dihydro-3 ,3 -dimethyl- 1 ,2-benzisothiazol-2- yl)acetyl]-L-4-(NN-dimethylcarbamyloxy)phenylalanine N-[2-(N-2, 10-camphorsultamyl)acetyl]-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-[2-(N-2, 10-camphorsultamyl)acetyl]-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-[2-(N-2, 10-camphorsultamyl)acetyl]-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-(4-hydroxy)prolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyrimidyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine piperazine-1 ,4-dicarboxylic acid bis-{4-[(2S)-2-tert-butoxycarbonyl-2- ((2R)- 1 -(toluene-4-sulfonyl)pyrrolidine-2-carboxamido)ethyl]phenyl } ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l -ylcarbonyloxy )]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy )phenylalanine N-(toluene-4-sulfonyl)-L-(4-oxo)prolyl-L-4-(4-methylpiperazin-l- ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)]phenylalariine N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)]phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4-(2- pyridyl)piperazin-l -ylcarbonyloxy)]phenylalanine tert-butyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)]phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(N-phenylthiocarbonyl)piperazin- 1 -ylcarbonyloxy )]phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4- methylhomopiperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester piperazine- 1,4-di carboxylic acid bis-{4-[(2S)-2-carboxyl-2-((2R)-l- (toluene-4-sulfonyl)pyrrolidine-2-carboxamido)ethyl]phenyl} ester N-(toluene-4-sulfonyl)-L-4-(methanesulfonyloxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-aminocarbonylbenzenesulfonyl)-L-prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(4-aminocarbonylbenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(4-amidinobenzenesulfonyl)-L-prolyl-L-4-(thiomoφholin-4- ylcarbonyloxy)phenylalanine N-(4-nitrobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)]phenylalanine N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- (2-pyridyl)piperazin-l-ylcarbonyloxy)]phenylalanine ethyl ester N-(4-fluorobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro-4-(4- (2 -pyridy Opiperazin- 1 -ylcarbony loxy )phenylalanine N-(4-fluorobenzenesulfonyl)thiazolidinyl-2-carbonyl-L-4-(4- methylhomopiperazin- 1 -ylcarbonyloxy )phenylalanine N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro- 4-(NN-dimethylcarbamyloxy)phenylalanine isopropyl ester N-(l-methylimidazole-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy )phenylalanine isopropyl ester N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-4-(4-(2 -pyridy Opiperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin- 1 - ylcarbonyloxy )phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine isopropyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(4-(2 -pyridy Opiperazin- 1 - ylcarbonyloxy )phenylalanine tert-butyl ester N-(toluene-4-sulfonyl)-L-(l -methanesulfony lpyrazin-3 -carbonyl)-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(toluene-4-sulfonyl)-L-4-(methanesulfonyloxy)prolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine N-(methanesulfonyl)-N-benzylglycinyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-bromobenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l -ylcarbonyloxy )phenylalanine tert-butyl ester N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (NN-dimethylcarbamyloxy)phenylalanine tert-butyl ester N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy )phenylalanine tert-butyl ester N-(4-fluorobenzenesulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l- ylcarbonyloxy)phenylalanine N-(4-fluorobenzenesulfonyl)-L-(4-hydroxy)prolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy )phenylalanine N-(4-trifluoromethoxybenzenesulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4- (4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy )phenylalanine N-( 1 -methylimidazole-4-sulfonyl)-L-prolyl-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine N-(l-methylimidazole-4-sulfonyl)-L-prolyl-L-3-chloro-4-(NN- dimethylcarbamyloxy)phenylalanine isopropyl ester N-(l-methylimidazole-4-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin- 1 -ylcarbony loxy )pheny lalanine N-(l-methylimidazole-4-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin- 1 -ylcarbonyloxy)phenylalanine N-(l -methylpyrazole-3-sulfonyl)-L-prolyl-L-4-(4-(2-pyridyl)piperazin-l - ylcarbonyloxy)phenylalanine N-( 1 -methy lpyrazole-3 -sulfonyl)-L-prolyl-L-4-(4-(2 -pyridy Opiperazin- 1 - ylcarbonyloxy )phenylalanine isopropyl ester N-(l -methy lpyrazole-3-sulfonyl)-L-prolyl-L-4-(4-(2 -pyridy Opiperazin- 1- ylcarbonyloxy)phenylalanine tert-butyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(4-(2- pyridyl)piperazin-l -ylcarbonyloxy )phenylalanine tert-butyl ester N-(l-methylimidazole-4-sulfonyl)-L-prolyl-L-3-chloro-4-(4-(2- pyridyl)piperazin-l -ylcarbonyloxy )phenylalanine isopropyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-4-(NN- dimethylcarbamyloxy)phenylalanine 2-phenoxyethyl ester N-(l-methylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl-L-3-chloro- 4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy )phenylalanine N-(l -methy lpyrazole-3-sulfonyl)-L-(5, 5 -dimethy l)thiaprolyl-L-3 -chloro- 4-(4-(2-pyridyl)piperazin- 1 -ylcarbonyloxy )pheny lalanine ethyl ester N-(3-chloro-l,5-dimethylpyrazole-3-sulfonyl)-L-(5,5-dimethyl)thiaprolyl- L-3-chloro-4-(4-(5-trifluoromethyl-2-pyridyl)piperazin- 1 - ylcarbonyloxy )phenylalanine and pharmaceutically acceptable salts thereof as well as any of the ester compounds recited above wherein one ester is replaced with another ester selected from the group consisting of methyl ester, ethyl ester, n-propyl ester, isopropyl ester, n-butyl ester, isobutyl ester, sec-butyl ester, tert-butyl ester and neopentyl ester. 17. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of formula I: wherein R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heterocyclic, substituted heterocylic, heteroaryl and substimted heteroaryl; R 2 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, substimted cycloalkyl, cycloalkenyl, substimted cycloalkenyl, heterocyclic, substimted heterocyclic, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, and R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 can form a heterocyclic or a substimted heterocyclic group; R 3 is selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and, when R 2 does not form a heterocyclic group with R 1 , R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 can form a heterocyclic or a substimted heterocyclic group; R 5 is -(CH 2 ) X -Ar-R 5 where R 5 is selected from the group consisting of -O-Z-NR 8 R 8' and -O-Z-R 12 wherein R 8 and R 8' are independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, heterocyclic, substituted heterocyclic, and where R 8 and R 8 are joined to form a heterocycle or a substimted heterocycle, R 12 is selected from the group consisting of heterocycle and substimted heterocycle, and Z is selected from the group consisting of -C(O)- and -SO 2 -, Ar is aryl, heteroaryl, substimted aryl or substimted heteroaryl, x is an integer of from 1 to 4; Q is -C(X)NR 7 - wherein R 7 is selected from the group consisting of hydrogen and alkyl; and X is selected from the group consisting of oxygen and sulfur; and pharmaceutically acceptable salts thereof. 18. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of formula IA: wherein R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocylic, heteroaryl and substimted heteroaryl; R 2 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, substimted cycloalkyl, cycloalkenyl, substimted cycloalkenyl, heterocyclic, substimted heterocyclic, substimted alkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, and R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 can form a heterocyclic or a substituted heterocyclic group; R 3 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substimted heteroaryl, heterocyclic, substimted heterocyclic and, when R 2 does not form a heterocyclic group with R 1 , R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 can form a heterocyclic or a substimted heterocyclic group; R 5 is -(CH 2 ) X -Ar-R 5' and R 5' is selected from the group consisting of -O-Z-NR 8 R 8' and -O-Z-R 12 wherein R 8 and R 8' are independently selected from the group consisting of hydrogen, alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, heterocyclic, substimted heterocyclic, and where R 8 and R 8' are joined to form a heterocycle or a substimted heterocycle, R 12 is selected from the group consisting of heterocycle and substimted heterocycle, and Z is selected from the group consisting of -C(O)- and -SO 2 -, Ar is aryl, heteroaryl, substimted aryl or substimted heteroaryl, x is an integer of from 1 to 4; R 6 is selected from the group consisting of amino, alkoxy, substimted alkoxy, cycloalkoxy, substimted cycloalkoxy, -O-(N-succinimidyl), -NH- adamantyl, -O-cholest-5-en-3-β-yl, -NHOY where Y is hydrogen, alkyl, substituted alkyl, aryl, and substimted aryl, -NH(CH 2 ) p COOY where p is an integer of from 1 to 8 and Y is as defined above, -OCH 2 NR 9 R 10 where R 9 is selected from the group consisting of -C(O)-aryl and -C(O)-substituted aryl and R 10 is selected from the group consisting of hydrogen and -CH 2 COOR n where R 11 is alkyl, and -NHSO 2 Z' where Z' is alkyl, substimted alkyl, cycloalkyl, substimted cycloalkyl, aryl, substimted aryl, heteroaryl, substituted heteroaryl, heterocyclic and substimted heterocyclic; Q is -C(X)NR 7 - wherein R 7 is selected from the group consisting of hydrogen and alkyl; and X is selected from the group consisting of oxygen and sulfur; and pharmaceutically acceptable salts thereof with the following provisos (A) when R 1 and R 2 together with the SO 2 group pendent to R 1 and the nitrogen pendent to R 2 form a saccharin-2-yl group, R 3 is -CH 3 , R 5 is p-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; (B) when R 1 is p-methylphenyl, R 2 and R 3 together with the nitrogen atom pendent to R 2 and the carbon atom pendent to R 3 form a pyrrodinyl ring derived from D-proline; R 5 is p-[(4-methylpiperazin-l-yl)NC(O)O- ]benzyl derived from D-phenylalanine and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 ; and (C) when R 1 is pyrimidin-2-yl, R 2 and R 3 together with the nitrogen atom bound to R 2 and the carbon atom bound to R 3 form a pyrrolidinyl ring, R 5 is p-[(CH 3 ) 2 NC(O)O-]benzyl and Q is -C(O)NH- then R 6 is not -OC(CH 3 ) 3 . 19. A pharmaceutical composition according to Claims 17 or 18 wherein R 1 is selected from the group consisting of alkyl, substimted alkyl, aryl, substimted aryl, heterocyclic, substituted heterocylic, heteroaryl and substituted heteroaryl. 20. A pharmaceutical composition according to Claims 17 or 18 wherein R 1 is selected from the group consisting of methyl, isopropyl, n- butyl, benzyl, phenethyl, phenyl, 4-methylphenyl, 4-t-butylphenyl, 2,4,6- trimethylphenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2,4- difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl, 2-chlorophenyl, 3- chlorophenyl, 4-chlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 3- chloro-4-fluorophenyl, 4-bromophenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl, 4-t-butoxyphenyl, 4-(3x dimethylamino-«-propoxy)-phenyl, 2-carboxyphenyl, 2- (methoxycarbonyl)phenyl, 4-(H 2 NC(O)-)phenyl, 4-(H 2 NC(S)-)phenyl, 4- cyanophenyl, 4-trifluoromethylphenyl, 4-trifluoromethoxyphenyl, 3,5-di- (trifluoromethyl)phenyl, 4-nitrophenyl, 4-aminophenyl, 4-(CH 3 C(O)NH- )phenyl, 4-(PhNHC(O)NH-)phenyl, 4-amidinophenyl, 4- methylamidinophenyl, 4-(CH 3 SC(=NH)-)phenyl, 4-chloro-3-(H 2 NS(O) 2 - )phenyl, 1 -naphthyl, 2-naphthyl, pyridin-2-yl, pyridin-3-yl, pyrimidin-2-yl, quinolin-8-yl, 2-(trifluoroacetyl)-l ,2,3 ,4-tetrahydroisoquinolin-7-yl, moφholin-4-yl, 2-thienyl, 5-chloro-2-thienyl, 2,5-dichloro-4-thienyl, 1-N- methylimidazol-4-yl, 1 -N-methy lpyrazol-3-yl, 1 -N-methy lpyrazol-4-yl, 1-N- butylpyrazol-4-y 1 , 1 -N-methy 1-3 -methy 1-5 -chloropyrazol-4-y 1 , 1 -N-methy 1-5 - methy 1-3 -chloropyrazol-4-yl, 2-thiazolyl and 5-methyl-l,3,4-thiadiazol-2-yl. 21. A pharmaceutical composition according to Claims 17 or 18 wherein R 2 is selected from the group consisting of hydrogen, methyl, phenyl, benzyl, -(CH 2 ) 2 -2-thienyl, and -(CH 2 ) 2 -φ. 22. A pharmaceutical composition according to Claims 17 or 18 wherein R 1 and R 2 together with the nitrogen atom bound to R 2 and the SO 2 group bound to R 1 are joined to form a heterocyclic group or substimted heterocyclic group. 23. A pharmaceutical composition according to Claims 17 or 18 wherein R 2 and R 3 together with the nitrogen atom bound to R 2 substiment and the carbon bound to the R 3 substiment form a heterocyclic group or a substimted heterocyclic group. 24. A pharmaceutical composition according to Claim 23 wherein the heterocyclic group is samrated. 25. A pharmaceutical composition according to Claim 23 wherein the heterocyclic group is selected from the group consisting of azetidinyl, thiazolidinyl, piperidinyl, piperazinyl, dihydroindolyl, tetrahydroquinolinyl, thiomoφholinyl, pyrrolidinyl, 4-hydroxypyrrolidinyl, 4-oxopyrrolidinyl, 4- fluoropyrrolidinyl, 4,4-difluoropyrrolidinyl, 4-(thiomoφholin-4-ylC(O)O- )pyrrolidinyl, 4-(CH 3 S(O) 2 O-)pyrrolidinyl, 3-phenylpyrrolidinyl, 3- thiophenylpyrrolidinyl, 4-aminopyrrolidinyl, 3-methoxypyrrolidinyl, 4,4- dimethylpyrrolidinyl, 4-N-Cbz-piperazinyl, 4-(CH 3 S(O) 2 -)piperazinyl, 5,5- dimethylthiazolindin-4-yl, 1 , 1-dioxo-thiazolidinyl, 1 , l-dioxo-5 ,5- dimethylthiazolidin-2-yl and 1,1-dioxothiomoφholinyl. 26. A pharmaceutical composition according to Claims 17 or 18 wherein R 3 is selected from the group consisting of methyl, phenyl, benzyl, diphenylmethyl, -CH 2 CH 2 -COOH, -CH 2 -COOH, 2-amidoethyl, iso-buty\, t- butyl, -CH 2 O-benzyl and hydroxymethyl. 21. A pharmaceutical composition according to Claims 17 or 18 wherein Q is -C(O)NH- or -C(S)NH-. 28. A pharmaceutical composition according to Claims 17 or 18 wherein Ar is aryl or substimted aryl. 29. A pharmaceutical composition according to Claim 28 wherein Ar is phenyl or substimted phenyl and x is 1. 30. A pharmaceutical composition according to Claim 17 or 18 wherein R 5 is selected from the group consisting of 3-[(CH 3 ) 2 NC(O)O-]benzyl, 4-[(CH 3 ) 2 NC(O)O-]benzyl, 4-[(CH 3 ) 2 NS(O) 2 O-]benzyl, 4-[(piρeridin-r-yl)C(O)O-]benzyl, 4-[(piperidin-4Xyl)C(O)O-]benzyl, 4-[(l Xmethylpiperidin-4Xyl)C(O)O-]benzyl, 4- [(4 ' -hydroxypiperidin- 1 ' -y 1)C (O)O-] benzyl , 4-[(4 ' -formyloxypiperidin- 1 ' -yl)C(O)O-]benzyl , 4-[(4 Xethoxycarbonylpiperidin- -yl)C(O)O-]benzyl , 4- [(4 ' -carboxylpiperidin- 1 ' -yl)C(O)O-]benzyl , 4-[(3 xhydroxymethylpiperidin-1 Xyl)C(O)O-]benzyl, 4-[(4Xhydroxymethylpiperidin- -yl)C(O)O-]benzyl, 4-[(4Xphenyl-l'-Boc-piperidin-4Xyl)-C(O)O-]benzyl, 4-[(4Xpiperidon-L-yl ethylene ketal)C(O)O-]benzyl, 4-[(piperazin-4Xyl)-C(O)O-]benzyl, 4-[(l XBoc-piperazin-4Xyl)-C(O)O-]benzyl, 4- [(4 ' -methy lpiperazin- 1 ' -yl)C(O)O-]benzyl , 4- [(4 ' -methy lhomopiperazin- 1 ' -y 1)C (O)O-] benzyl , 4-[(4X(2-hydroxyethyl)piperazin-r-yl)C(O)O-]benzyl, 4-[(4 ' -pheny lpiperazin- 1 ' -yl)C(O)O-]benzyl , 4-[(4X(pyridin-2-yl)piperazin-l Xyl)C(O)O-]benzyl, 4-[(4X(4-trifluoromethylpyridin-2-yl)piperazin- -yl)C(O)O-]benzyl, - [(4 x(pyrimidin-2-y Opiperazin- 1 ' -yl)C(O)O-]benzyl , -[(4Xacetylpiperazin- -yl)C(O)O-]benzyl, -[(4 X (phenylC(O)-)piperazin-r-yl)C(O)O-]benzyl, -[(4 X (pyridin-4-ylC(O)-)piperazin-r-yl)C(O)O-]benzyl, -[(4 X (phenylNHC(O)-)piperazin-l Xyl)C(O)O-]benzyl, -[(4 X (phenylNHC(S)-)piperazin-r-yl)C(O)O-]benzyl, -[(4 X methanesulfonylpiperazin- -yl-C(O)O-)benzyl, - [(4 ' -trifluoromethanesulfony lpiperazin- 1 Xyl-C(O)O-)benzyl , -[(moφholin-4Xyl)C(O)O-]benzyl, -nitro-4-[(moφholin-4Xyl)-C(O)O-]benzyl, -[(thiomoφholin-4Xyl)C(O)O-]benzyl, - [(thiomoφholin-4 ' -y 1 sulfone)-C(O)O-]benzyl , -[(pyrrolidin-r-yl)C(O)O-]benzyl, - [(2 ' -methylpy rrolidin- 1 ' -y l)C(O)O-] benzyl , -[(2 X (methoxycarbonyl)pyrrolidin-r-yl)C(O)O-]benzyl, - [(2 x(hydroxymethy Opyrrolidin- 1 ' -yl)C(O)O-]benzyl , -[(2X(N,N-dimethylamino)ethyl)(CH 3 )NC(O)O-]benzyl, -[(2 X (N-methyl-N-toluene-4-sulfonylamino)ethyl)(CH 3 )N- C(O)O-]benzyl, -[(2 X (moφholin-4 X yl)ethyl)(CH 3 )NC(O)O-]benzyl, -[(2X(hydroxy)ethyl)(CH 3 )NC(O)O-]benzyl, -[bis(2'-(hydroxy)ethyl)NC(O)O-]benzyl, -[(2 X (formyloxy)ethyl)(CH 3 )NC(O)O-]benzyl, -[(CH 3 OC(O)CH 2 )HNC(O)O-]benzyl, -[2 X (phenylNHC(O)O-)ethyl-]HNC(O)O-]benzyl, -chloro-4-[(CH 3 ) 2 NC(O)O-]benzyl, -chloro-4- [(4 ' -methy lpiperazin- 1 ' -y 1)C (O)O-] benzyl , -chloro-4-[(4 X(pyridin-2-yl)piperazin- 1 Xyl)C(O)O-]benzyl , -chloro-4-[(thiomoφholin-4Xyl)C(O)O-]benzyl, and -fluoro-4-[(CH 3 ) 2 NC(O)O-]benzyl. 31. A pharmaceutical composition according to Claimlδ wherein R 6 is selected from the group consisting of 2,4-dioxo-tetrahydrofuran-3-yl (3,4- enol), methoxy, ethoxy, «-propoxy, isopropoxy, «-butoxy, t-butoxy, cyclopentoxy, cyclopropylmethoxy, neopentoxy, 2- -isopropyl-4-β- methy lcyclohexoxy, 2-β-isopropyl-4-β-methylcyclohexoxy, 2- methoxyphenoxy, 2-(moφholin-4-yl)ethoxy, -O(CH 2 CH 2 O) 2 CH 3 , 2- (ρhenoxy)ethoxy, -OCH 2 C(CH 3 ) 2 NHBoc, -NH 2 , benzyloxy, -NHCH 2 COOH, -NHCH 2 CH 2 COOH, -NH-adamantyl, -NHSO 2 -p-CH 3 -φ, -NHCH 2 CH 2 COOCH 2 CH 3 , -NHOY' where Y' is hydrogen, methyl, tsσ-propyl or benzyl, -O-(N-succinimidyl), -O-cholest-5- en-3-β-yl, -OCH 2 -OC(O)C(CH 3 ) 3 , -O(CH 2 ) z NHC(O)W where z is 1 or 2 and W is selected from the group consisting of pyrid-3-yl, N-methylpyridyl, and N-methyl-l ,4-dihydro-pyrid-3-yl, -NR"C(O)-R' where R' is aryl, heteroaryl or heterocyclic and R" is hydrogen or -CH 2 C(O)OCH 2 CH 3 . 32. A method for binding VLA-4 in a biological sample which method comprises contacting the biological sample with a compound of Claim 1 or 2 under conditions wherein said compound binds to VLA-4. 33. A method for treating an inflammatory condition in a mammalian patient which condition is mediated by VLA-4 which method comprises administering to said patient a therapeutically effective amount of a pharmaceutical composition of Claim 17 or 18. 34. The method according to Claim 33 wherein said inflammatory condition is selected from the group consisting of asthma, Alzheimer's disease, atherosclerosis, AIDS dementia, diabetes, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, tissue transplantation, tumor metastasis, meningitis, encephalitis, stroke, nephritis, retinitis, atopic dermatitis, psoriasis, myocardial ischemia and acute leukocyte-mediated lung injury.

Inventors: ASHWELL SUSAN, BAUDY REINHARDT BERNHARD, DRESSEN DARREN B, GRANT FRANCINE S, KONRADI ANDREI W, KREFT ANTHONY, LOMBARDO LOUIS JOHN, PLEISS MICHAEL A, SARANTAKIS DIMITRIOS, SEMKO CHRISTOPHER M, THORSETT EUGENE D, ASHWELL, SUSAN, BAUDY, REINHARDT, BERNHARD, DRESSEN, DARREN, B., GRANT, FRANCINE, S., KONRADI, ANDREI, W., KREFT, ANTHONY, LOMBARDO, LOUIS, JOHN, PLEISS, MICHAEL, A., SARANTAKIS, DIMITRIOS, SEMKO, CHRISTOPHER, M., THORSETT, EUGENE, D.
Applicants: AMERICAN HOME PROD, ASHWELL SUSAN, ATHENA NEUROSCIENCES INC, BAUDY REINHARDT BERNHARD, DRESSEN DARREN B, GRANT FRANCINE S, KONRADI ANDREI W, KREFT ANTHONY, LOMBARDO LOUIS JOHN, PLEISS MICHAEL A, SARANTAKIS DIMITRIOS, SEMKO CHRISTOPHER M, THORSETT EUGENE D, AMERICAN HOME PRODUCTS CORPORATION, ASHWELL, SUSAN, ATHENA NEUROSCIENCES, INC., BAUDY, REINHARDT, BERNHARD, DRESSEN, DARREN, B., GRANT, FRANCINE, S., KONRADI, ANDREI, W., KREFT, ANTHONY, LOMBARDO, LOUIS, JOHN, PLEISS, MICHAEL, A., SARANTAKIS, DIMITRIOS, SEMKO, CHRISTOPHER, M., THORSETT, EUGENE, D.
Application year: 1998
Main classification: C07D311
IPC codes: A61K31, A61K38, A61K45, A61P1, A61P3, A61P9, A61P11, A61P13, A61P17, A61P19, A61P25, A61P27, A61P29, A61P35, A61P37, C07D207, C07D277, C07D279, C07D311, C07D403, C07K5, G01N33