CYCLIC CARBAMATES AND ISOXAZOLIDINES AS IIB/IIIA ANTAGONISTS

Abstract: This invention relates generally to cyclic carbamates and hydroxylamines which are useful as antagonists of the platelet glycoprotein IIb/IIIa fibrinogen receptor complex, to pharmaceutical compositions containing such compounds, processes for preparing such compounds, and to methods of using these compounds for the inhibition of platelet aggregation, as thrombolytics, and/or for the treatment of thromboembolic disorders.

Description: Title Cyclic Carba ates and Isoxazolidines as IIB/IIIA Antagonists Field of the Invention The present invention relates generally to cyclic carbamates and isoxazolidines which are useful as antagonists of the platelet glycoprotein Ilb/IIIa fibrinogen receptor complex, to pharmaceutical compositions containing such compounds, processes for preparing such compounds, and to methods of using these compounds for the inhibition of platelet aggregation, as thrombolytics, and/or for the treatment of thromboembolic disorders . Background of the Invention Hemostasis is the normal physiological process in which bleeding from an injured blood vessel is arrested. It is a dynamic and complex process in which platelets play a key role. Within seconds of vessel injury, resting platelets become activated and are bound to the exposed matrix of the injured area by a phenomenon called platelet adhesion. Activated platelets also bind to each other in a process called platelet aggregation to form a platelet plug. The platelet plug can stop bleeding quickly, but it must be reinforced by fibrin for long-term effectiveness, until the vessel injury can be permanently repaired. Thrombosis may be regarded as the pathological condition wherein improper activity of the hemostatic mechanism results in intravascular thrombus formation. Activation of platelets and the resulting platelet aggregation and platelet factor secretion has been associated with a variety of pathophysiological conditions including cardiovascular and cerebrovascular thromboembolic disorders, for example, the romboembolic disorders associated with unstable angina, myocardial infarction, transient lschemic attack, stroke, atherosclerosis and diabetes. The contribution of platelets to these disease processes stems from their ability to form aggregates, or platelet thrombi, especially in the arterial wall following injury. Platelets are activated by a wide variety of agonists resulting in platelet shape change, secretion of granular contents and aggregation. Aggregation of platelets serves to further focus clot formation by concentrating activated clotting factors at the site of injury. Several endogenous agonists including adenosine diphosphate (ADP) , serotonin, arachidonic acid, thrombin, and collagen, have been identified. Because of the involvement of several endogenous agonists in activating platelet function and aggregation, an inhibitor which acts against all agonists would represent a more efficacious antiplatelet agent than currently available antiplatelet drugs, which are agonist-specific. Current antiplatelet drugs are effective against only one type of agonist; these include aspirin, which acts against arachidonic acid; ticlopidme, which acts against ADP; thromboxane A ? synthetase inhibitors or receptor antagonists, which act against thromboxane A 2 ; and hirudm, which acts against thrombin. Recently, a common pathway for all known agonists has been identified, namely platelet glycoproteiπ Ilb/IIIa complex (GPIIb/IIIa) , which is the membrane protein mediating platelet aggregation. A recent review of GPIIb/IIIa is provided by Phillips et al. Cell (1991) 65: 359-362. The development of a GPIIb/IIIa antagonist represents a promising new approach for antiplatelet therapy. GPIIb/IIIa does not bind soluble proteins on unstimulated platelets, but GPIIb/IIIa in activated platelets is known to bind four soluble adhesive proteins, namely fibrinogen, von Willebrand factor, fibronectin, and vitronectin. The binding of fibrinogen and von Willebrand factor to GPIIb/IIIa causes platelets to aggregate. The binding of fibrinogen is mediated in part by the Arg-Gly-Asp (RGD) recognition sequence which is common to the adhesive proteins that bind GPIIb/IIIa. Several RGD-peptidomimetic compounds have been reported which block fibrinogen binding and prevent the formation of platelet thrombi. European Patent Application Publication Number 478363 formula: R European Patent Application Publication Number 478328 relates to compounds having the general formula: European Patent Application Publication Nu ber 525629 (corresponds to Canadian Patent Application Publication Number 2,074,685) discloses compounds having the general formula: PCT Patent Application 9307867 relates to compounds having the general formula: European Patent Application Publication Number 4512831 relates to compounds having the general formula: R X-(CH 2 ) m -Y-(CH 2 ) k -C-NH-CH-CH-Z O R 1 Copending commonly assigned US patent application (USSN 08/337,920, filed 11/10/94, Wityak et al . ; published as W095/13155, 6/1/95) discloses compounds having the general formula: which are useful as IIB/IIIA antagonists. Copending commonly assigned US patent application (USSN 08/455,768, filed 5/31/95, Voss et al . ) discloses compounds having the general formula: Y which are useful as α v β 3 antagonists. None of the above references teaches or suggests the compounds of the present invention which are described in detail below. Summary of the Inventio One aspect of this invention provides novel compounds of Formula I (described below) which are useful as antagonists of the platelet glycoprotem Ilb/Ilia complex. The compounds of the present invention inhibit the binding of fibrinogen to platelet glycoprotein Ilb/IIIa complex and inhibit the aggregation of platelets. The present invention also includes pharmaceutical compositions containing such compounds of Formula I, and methods of using such compounds for the inhibition of platelet aggregation, as thrombolytics, and/or for the treatment of thromboembolic disorders. The present invention also includes methods of treating cardiovascular disease, thrombosis or harmful platelet aggregation, reocclusion following thrombolysis, reperfusion injury, or restenosis by administering a compound of Formula I alone or in combination with one or more additional therapeutic agents selected from: anti-coagulants such as warfarin or hepaπn; anti-platelet agents such as aspirin, piroxicam or ticlopidine; thrombin inhibitors such as boroarginme derivatives, hirudm or argatroban; or thrombolytic agents such as tissue plasmmogen activator, anistreplase, urokinase or streptokmase; or combinations thereof. Also included in the present invention are pharmaceutical kits comprising one or more containers containing pharmaceutical dosage units comprising a compound of Formula I, for the treatment of cell adhesion related disorders, including but not limited to thromboembolic disorders . Detailed Description of r.hp Invention This invention relates to novel compounds of the Formula I : γ (I) their enantiomeπc, diastereomeric, pharmaceutically acceptable salts or prodrug forms thereof wherein: R 1 is selected from R 2 HN-, R 2 HN(R 2 N=)C-, R 2 HN(CH 2 ) q Z-, R 2 HN(R 2 N=)C(CH 2 ) q Z-, R 2 HN(R 2 N= ) CN(R 2 ) - , R 2 HNC(0)-, R 2 (R 5 0)N(R 2 N=)C-, or R 2 HN(R 5 ON=)C-; Z is selected from a bond (i.e. is absent), O, S, or S(=0), S(=0) ; R 2 is selected from H, aryl (Ci-Cio alkoxy) carbonyl, or Ci-Cio alkoxycarbonyl, C 1 -C 4 alkyl, C 3 -C 6 alkenyl; R 3 is selected from H, C1-C 6 alkyl, C 2 -C 6 alkenyl, C -C 6 alkynyl, C3-C7 cycloalkyl, - (phenyl) - substituted with 0-2 R 6a , or - (pyπdyl) - substituted with 0- 2R 6 ; R is selected from H or C1-C 1 0 alkyl substituted with 0-1 R 4b ; R 4b is selected from Ci-Cβ alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C7 cycloalkyl, C 7 -C 14 bicycloalkyl, hydroxy, Ci-Cδ alkoxy, Cι-C 6 alkylthio, Cι-C 6 alkylsulfmyl, Cι-C 6 alkylsulfonyl, nitro, Ci-Cβ alkylcarbonyl, C 6 -Cιo aryl, -N(R 12 )R 13 ; halo, CF 3< CN, C 1 -C 6 alkoxycarbonyl, carboxy, piperldinyl, morpholmyl or pyridmyl; Ar is selected from: a single bond (i.e., Ar is not present), -(phenyl)- substituted with 0-2 R 6a , - (piperidinyl) - substituted with 0-2 R 6a , or -(pyridyl)- substituted with 0-2 R 6a ; R 6a is selected from C 1 -C4 alkyl, C 1 -C 4 alkoxy, halo, CF 3 , N0 2 , Or NR 12 R 13 ; X is selected from -C(O)- or a single bond, i.e. X is absent; Y is selected from hydroxy, C to Cio alkyloxy, C 3 to Cn cycloalkyloxy, Q to Cio aryloxy, C 7 to Cn aralkyloxy, C 3 to Cio alkylcarbonyloxyalkyloxy, C 3 to Cio alkoxycarbonyloxyalkyloxy, C 2 to Cio alkoxycarbonylalkyloxy, C5 to C o cycloalkylcarbonyloxyalkyloxy, C 5 to Cio cycloalkoxycarbonyloxyalkyloxy, C 5 to Cio cycloalkoxycarbonylalkyloxy, C 7 to Cn aryloxycarbonylalkyloxy, C % to C 12 aryloxycarbonyloxyalkyloxy, Cg to C 1 2 arylcarbonyloxyalkyloxy, C 5 to Cio alkoxyalkylcarbonyloxyalkyloxy, C 5 to Cio ( 5-alkyl- 1, 3-dioxa-cyclopenten-2-one-yl)methyloxy, Cio to C 1 ( 5-aryl-l,3-dioxa-cyclopenten-2-one-yl)methyloxy, (R 2 )HN-(Cι-Cιo alkoxy)-; m is 0-2 ; n is 0-4; R 9 and R 10 are each independently selected from H, C -C δ alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 7 cycloalkyl, - (phenyl) - substituted with 0-2 R 6a , or - (pyridyl) - substituted with 0-2R 6a ; R 11 is -C(=0)-0-R 1 a , -C(=0)-R 14b , -C(=0)N(R 14b) 2 , -C(=0)NHS0 2 R 14 , -C(=0)NHC(=0)R 14b , -C(=0)NHC(=0)OR 1 a , -C(=0)NHS0 2 NHR 14b , -C( =S)-NH-R 1 b , -NH-C(=0)-0-R 1 a , -NH-C(=0)R 1 b , -NH-C(=0)-NH-R 14b , -S0 2 -0-R 1 a , -S0 2 -R 14a , -S0 2 -N(R 1 ) 2 , -S0 2 -NHC(=0)OR 1 b , -P(=S) (OR 14a ) 2 , -P(=0) (OR 14a ) 2 , -P(=S) (R 1 a ) 2 , -P(=0) (R 14a ) 2 , or ? R 12 and R 13 are each independently selected from H, Ci-Cio alkyl, C -Cio alkoxycarbonyl, Ci-Cio alkylcarbonyl, C -Cio alkylsulfonyl, heteroaryl (C 1 -C 4 alkyl )sulfonyl, aryl(Cι-Cιo alkyl) sulfonyl, arylsulfonyl, aryl, heteroarylcarbonyl, heteroarylsulfonyl, or heteroarylalkylcarbonyl, wherein said aryls and heteroaryls are optionally substituted with 0-3 substituents selected from the group consisting of C 1 -C 4 alkyl, C 1 -C 4 alkoxy, halo, CF 3 , and N0 2 ; Cι-C 8 alkyl substituted with 0-2R 15 , C 2 -C 8 alkenyl substituted with 0-2R 15 , C 2 -Cβ alkynyl substituted with 0-2R 15 , C 3 -C 8 cycloalkyl substituted with 0-2R ls , aryl substituted with 0-4R 15 , aryl ( Cι-C 6 alkyl ) -substit uted with 0- 4R 15 , a 5-10 membered heterocyclic ring system having 1-3 heteroatoms selected independently from 0,S, and N, said heterocyclic ring being substituted with 0-4 R 15 or C1-C6 alkyl substituted with a 5-10 membered heterocyclic ring system having 1-3 heteroatoms selected independently from 0,S, and N, said heterocyclic ring being substituted with 0-4R15; R 14b 1S R 14a or H; R 15 is H, halogen, CF 3 , CN, N0 2 , NR 12 R 13 , Cι-C 8 alkyl, C 2 - C 6 alkenyl, C 3 -C 11 cycloalkyl, C 4 -C 11 cycloalkylakyl, aryl, aryl(Cι-C 6 alkyl)-, C 1 -C 6 alkoxy, or C 1 -C4 alkoxycarbonyl; provided that m and n are chosen such that the number of atoms connecting R 1 and Y is m the range of 10-18. Preferred compounds of the present invention are compounds wherein: R 1 is selected from R 2 NHC(=NR 2 )- or R 2 NHC (=NR 2 ) NH- ; R 2 is selected from H, Ci-Cio alkoxycarbonyl, or C 1 -C 4 alkyl; R 3 is selected from H, C1-C6 alkyl, or - (phenyl) - substituted with 0-2R 6 ; R 5 is selected from H or C 1 -C 4 alkyl Ar is -(phenyl)- substituted with 0-2 R 5a ; R 6a is selected from C 1 -C 4 alkyl, C 1 -C 4 alkoxy, halo, CF 3 , NO 2 , Or NR 12 R 13 ; X is selected from -C(O)- or a single bond, i.e. X is absent ; Y is selected from: hydroxy; Ci to Cio alkoxy; methylcarbonyloxymethoxy- ; ethylcarbonyloxymethoxy- ; t-butylcarbonyloxymethoxy- ; cyclohexylcarbonyloxymethoxy- ; 1- (methylcarbonyloxy) ethoxy- ; 1- (ethylcarbonyloxy) ethoxy-; 1- (t-butylcarbonyloxy) ethoxy- ; 1- (cyclohexylcarbonyloxy) ethoxy-,- -propyloxycarbonyloxymethoxy- ; t-butyloxycarbonyloxymethoxy- ,- 1- (l-propyloxycarbonyloxy) ethoxy-; 1- (cyclohexyloxycarbonyloxy) ethoxy- ; 1- (t-butyloxycarbonyloxy) ethoxy-; (5-methyl-l, 3-dιoxacyclopenten-2-on-4-yl)methoxy- ; (5- ( t-butyl) -1, 3-dιoxacyclopenten-2-on-4- y1 ) methoxy- ; (l,3-dιoxa-5-phenyl-cyclopenten-2-on-4-yl)methoxy-; 1- (2- (2-methoxypropyl)carbonyloxy) ethoxy-; is 1 or 2 ; n is 1 or 2; R 9 and R 10 each are H; R 12 is selected from H, Ci-C δ alkyl, C 1 -C 4 alkoxycarbonyl, Ci-Ce alkylcarbonyl, Cι-C 6 alkylsulfonyl, aryl(Cι-C 4 alkyl) sulfonyl, heteroaryl (C1-C4 alkyl) sulfonyl, arylsulfonyl, heteroarylsulfonyl, aryl, pyridylcarbonyl or pyridylmethylcarbonyl , wherein said aryls and heteroaryls are optionally substituted with 0-3 substituents selected from the group consisting of: C1-C4 alkyl, C1-C4 alkoxy, halo, CF 3 , and N0 2 ; and R 13 is H. The most preferred compounds of the present invention are: Cis-3-[2- [2 -methyl -3- (4-amidinophenyl) - isoxazolidin-5-yl] -acetyl ] amino-N- (3- methylphenylsulfonyl ) -L-alanine methyl ester monotrifluoroacetic acid Trans-3- [2- [2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-benzyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] -N- (3-methylphenylsulfonyl ) -L- alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-isopropyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (2- ethylphenylsulfonyl) -L-alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3, 5-dimethyloxazol-4- ylsulfonyl) -L-alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N-n-butyloxycarbonyl-L- alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-phenyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amidinophenyl ) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-benzyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-isopropyl-3- (4-amidinophenyl ) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (2- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3-[2-[2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3, 5-dimethyloxazol-4- ylsulfonyl) -L-alanine monohydrogenchloride I ! Cis-3- [2- [2-methyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N-n-butyloxycarbony1-L- alanine monohydrogenchloride Cis-3- [2- [2-phenyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazin-6-yl] acetyl] amino] -N- [ (3- methylphenyl) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] etrahydro-3- benzyl-2-oxo-2H-l, 3-oxazin-6-yl] acetyl] amino] -N- [ (3- methylphenyl) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazin-6-yl] acetyl] amino] -N- [ (2- methylphenyl) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazin-6-yl]acetyl] amino] -N- [ (3, 5- dimethylisoxazol-4-yl) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazin-6-yl] acetyl] amino] -N- (n- butyloxycarbonyl) -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazin-6-yl] acetyl] amino] -N- [ (3- methylphenyl) sulfonyl] -L-alanine monohydrogenchloride Cιs-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- benzyl-2-oxo-2H-l,3-oxazιn-6-yl]acetyl] am o] -N- [ (3- ethylphenyl ) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl]acetyl] ammo] -N- [ (2- ethylphenyl) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (ammoimmomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl] acetyl] amino] -N- [(3,5- dιmethylιsoxazol-4-yl) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (ammoimmomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl]acetyl] amino] -N- (n- butyloxycarbonyl ) -L-alanine monohydrogenchloride The compounds of Formula I of the present invention are useful for the treatment (including prevention) of thromboembolic disorders. The term "thromboembolic disorders" as used herein includes conditions involving platelet activation and aggregation, such as arterial or venous cardiovascular or cerebrovascular thromboembolic disorders, including, for example, thrombosis, unstable angina, first or recurrent myocardial infarction, lschemic sudden death, transient ischemic attack, stroke, atherosclerosis, venous thrombosis, deep vein thrombosis, thrombophlebitis, arterial embolism, coronary and cerebral arterial thrombosis, myocardial infarction, cerebral embolism, kidney embolisms, pulmonary embolisms, or such disorders associated with diabetes, comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound of Formula I described above. The compounds of the present invention are useful for inhibiting the binding of fibrinogen to blood platelets, inhibiting aggregation of blood platelets, treating thrombus formation or embolus formation, or preventing thrombus or embolus formation in a mammal. The compounds of the invention may be used as a medicament for blocking fibrinogen from acting at its receptor site in a mammal. Compounds of the invention may be administered to patients where prevention of thrombosis by inhibiting binding of fibrinogen to the platelet membrane glycoprotein complex Ilb/IIIa receptor is desired. They are useful in surgery on peripheral arteries (arterial grafts, carotid endarterectomy) and in cardiovascular surgery where manipulation of arteries and organs, and/or the interaction of platelets with artificial surfaces, leads to platelet aggregation and consumption, and where the aggregated platelets may form thrombi and thromboemboli. The compounds of the present invention may be administered to these surgical patients to prevent the formation of thrombi and thromboemboli. Extracorporeal circulation is routinely used during cardiovascular surgery in order to oxygenate blood. Platelets adhere to surfaces of the extracorporeal circuit. Adhesion is dependent on the interaction between GPIIb/IIIa on the platelet membranes and fibrinogen adsorbed to the surface of the extracorporeal circuit. Platelets released from artificial surfaces show impaired homeostatic function. The compounds of the invention may be administered to prevent such ex vivo adhesion. The compounds of the present invention may be used for other ex vivo applications to prevent cellular adhesion in biological samples. Other applications of these compounds include prevention of platelet thrombosis, thromboembolism, and reocclusion during and after thrombolytic therapy and prevention of platelet thrombosis, thromboembolism and reocclusion after angioplasty of coronary and other arteries and after coronary artery bypass procedures . The compounds of the present invention may also be used to prevent myocardial infarction. The compounds of the present invention are useful as thrombolytics for the treatment of thromboembolic disorders. The compounds of the present invention can also be administered in combination with one or more additional therapeutic agents select from: anti-coagulant or coagulation inhibitory agents, such as heparin or warfarin; anti-platelet or platelet inhibitory agents, such as aspirin, piroxicam, or ticlopidine; thrombin inhibitors such as boropeptides, hirudin or argatroban; or thrombolytic or fibrinolytic agents, such as plasminogen activators, anistreplase, urokinase, or streptokinase. The compounds of Formula I of the present invention can be administered in combination with one or more of the foregoing additional therapeutic agents, thereby to reduce the doses of each drug required to achieve the desired therapeutic effect. Thus, the combination treatment of the present invention permits the use of lower doses of each component, with reduced adverse, toxic effects of each component. A lower dosage minimizes the potential of side effects of the compounds, thereby providing an increased margin of safety relative to the margin of safety for each component when used as a single agent. Such combination therapies may be employed to achieve synergistic or additive therapeutic effects for the treatment of thromboembolic disorders. By "therapeutically effective amount" it is meant an amount of a compound of Formula I that when administered alone or in combination with an additional therapeutic agent to a cell or mammal is effective to prevent or ameliorate the thromboembolic disease condition or the progression of the disease. By "administered combination" or "combination therapy" it is meant that the compound of Formula I and one or more additional therapeutic agents are administered concurrently to the mammal being treated. When administered m combination each component may be administered at the same time or sequentially m any order at different points in time. Thus, each component may be administered separately but sufficiently closely in time so as to provide the desired therapeutic effect. The term anti-coagulant agents (or coagulation inhibitory agents), as used herein, denotes agents that inhibit blood coagulation. Such agents include warfarin (available as Coumadin™) and heparm. The term anti-platelet agents (or platelet inhibitory agents) , as used herein, denotes agents that inhibit platelet function such as by inhibiting the aggregation, adhesion or granular secretion of platelets. Such agents include the various known non-steroidal anti-inflammatory drugs (NSAIDS) such as aspirin, lbuprofen, naproxen, sulindac, mdomethacin, mefenamate, droxicam, diclofenac, sulfinpyrazone, and piroxicam, including pharmaceutically acceptable salts or prodrugs thereof. Of the NSAIDS, aspirin (acetylsalicyclic acid or ASA) , and piroxicam. Piroxicam is commercially available from Pfizer Inc. (New York, NY) , as Feldane™. Other suitable antiplatelet agents include ticlopidine, including pharmaceutically acceptable salts or prodrugs thereof. Ticlopidine is also a preferred compound since it is known to be gentle on the gastro-mtestinal tract in use. Still other suitable platelet inhibitory agents include thromboxane-A2-receptor antagonists and thromboxane-A2-synthetase inhibitors, as well as pharmaceutically acceptable salts or prodrugs thereof. The phrase thrombin inhibitors (or anti-thrombin agents), as used herein, denotes inhibitors of the se me protease thrombin and other inhibitors of \ 6 thrombin synthesis such as Factor XA. By inhibiting thrombin, various thrombin-mediated processes, such as thrombin-mediated platelet activation (that is, for example, the aggregation of platelets, and/or the granular secretion of plasminogen activator inhibitor-1 and/or serotonin) and/or fibrin formation are disrupted. Such inhibitors include boroarginine derivatives and boropeptides, hirudin and argatroban, including pharmaceutically acceptable salts and prodrugs thereof. Boroarginine derivatives and boropeptides include N-acetyl and peptide derivatives of boronic acid, such as C-terminal α-aminoboronic acid derivatives of lysine, ornithine, arginine, homoarginine and corresponding isothiouronium analogs thereof. The term hirudin, as used herein, includes suitable derivatives or analogs of hirudin, referred to herein as hirulogs, such as disulfatohirudin. Boropeptide thrombin inhibitors include compounds described in Kettner et al., U.S. Patent No. 5,187,157 and European Patent Application Publication Number 293 881 A2 , the disclosures of which are hereby incorporated herein by reference. Other suitable boroarginine derivatives and boropeptide thrombin inhibitors include those disclosed in PCT Application Publication Number 92/07869 and European Patent Application Publication Number 471 651 A2, the disclosures of which are hereby incorporated herein by reference, in their entirety. The phrase thrombolytics (or fibrinolytic) agents (or thrombolytics or fibrinolytics) , as used herein, denotes agents that lyse blood clots (thrombi) . Such agents include tissue plasminogen activator, anistreplase, urokinase or streptokinase, including pharmaceutically acceptable salts or prodrugs thereof. Tissue plasminogen activator (tPA) is commercially available from Genentech Inc., South San Francisco, California. The term anistreplase, as used herein, refers to anisoylated plasminogen streptokinase ?- activator complex, as described, for example, in European Patent Application No. 028,489, the disclosures of which are hereby incorporated herein by reference herein, in their entirety. Anistreplase is commercially available as Emmase™. The term urokinase, as used herein, is intended to denote both dual and single chain urokinase, the latter also being referred to herein as prourokmase. Administration of the compounds of Formula I of the invention combination with such additional therapeutic agent, may afford an efficacy advantage over the compounds and agents alone, and may do so while permitting the use of lower doses of each. A lower dosage minimizes the potential of side effects, thereby providing an increased margin of safety. GPIIb/IIIa is known to be overexpressed in metastatic tumor cells. The compounds or combination products of the present invention may also be useful for the treatment, including prevention, of metastatic cancer. The compounds of the present invention are also useful as standard or reference compounds, for example as a quality standard or control, in tests or assays involving the binding of fibrinogen to platelet GPIIb/IIIa. Such compounds may be provided m a commercial kit, for example, for use in pharmaceutical research involving GPIIb/IIIa. The compounds of the present invention may also be used in diagnostic assays involving platelet GPIIb/IIIa. The compounds herein described may have asymmetric centers. Unless otherwise indicated, all chiral, diastereomenc and racemic forms are included m the present invention. Many geometric isomers of olefms, C=N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. It will be appreciated that compounds of the present [ 8 invention that contain asymmetrically substituted carbon atoms may be isolated in optically active or racemic forms. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis, from optically active starting materials. All chiral, diastereomeπc, racemic forms and all geometric lsomeric forms of a structure are intended, unless the specific stereochemistry or isomer form is specifically indicated. When any variable (for example but not limited to, R 2 , R 4b , R 6a , R 12 ,and R 13 , n, etc.) occurs more than one t me m any constituent or in any formula, its definition on each occurrence is independent of its definition at every other occurrence. Thus, for example, if a group is shown to be substituted with 0-2 R 4 , then said group may optionally be substituted with up to two R 4 and R 4 at each occurrence is selected independently from the defined list of possible R 4 . When a bond to a substituent is shown to cross the bond connecting two atoms in a ring, then such substituent may be bonded to any atom on the ring. When a bond joining a substituent to another group s not specifically shown or the atom in such other group to which the bond joins is not specifically shown, then such substituent may form a bond with any atom on such other group. When a substituent is listed without indicating the atom via which such substituent is bonded to the rest of the compound of Formula I, then such substituent may be bonded via any atom in such substituent. For example, when the substituent is piperidinyl, or morpholmyl, unless specified otherwise, said piperidinyl or morphol yl, tetrazolyl group may be bonded to the rest of the compound of Formula I via any atom in such piperidinyl or morpholinyl, tetrazolyl group. Combinations of substituents and/or variables are permissible only if such combinations result in stable 1 3 compounds. By stable compound or stable structure it is meant herein a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent. The term "substituted", as used herein, means that any one or more hydrogen on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency is not exceeded, and that the substitution results m a stable compound. When a substitent is keto (i.e., =0), then 2 hydrogens on the atom are replaced. As used herein, "alkyl" is intended to include both branched and straight -chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms (for example, "Ci-Cio" denotes alkyl having 1 to 10 carbon atoms); "alkoxy" represents an alkyl group of indicated number of carbon atoms attached through an oxygen bridge; "cycloalkyl" is intended to include saturated ring groups, including mono-, bi-, or poly- cyclic ring systems, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and adamantyl; and "bicycloalkyl" is intended to include saturated bicyclic ring groups such as [3.3. O]bicyclooctane, [4.3.0]bicyclononane, [4.4.0]bicyclodecane (decal ) , [2.2.2] bicyclooctane, and so forth. "Alkenyl" is intended to include hydrocarbon chains of either a straight or branched configuration and one or more unsaturated carbon-carbon bonds which may occur in any stable point along the chain, such as ethenyl, propenyl and the like; and "alkynyl" is intended to include hydrocarbon chains of either a straight or branched configuration and one or more triple carbon-carbon bonds which may occur in any stable point along the chain, such as ethynyl, propynyl and the like. The terms "alkylene", "alkenylene" , "phenylene", and the like, refer to alkyl, alkenyl, and phenyl groups, respectively, which are connected by two bonds to the rest of the structure of Formula I. Such "alkylene", "alkenylene", "phenylene", and the like, may alternatively and equivalently be denoted herein as " - (alkyl ) - " , " - (alkenyl ) - " and " - (phenyl ) - " , and the like. "Halo" or "halogen" as used herein refers to fluoro, chloro, bromo and iodo; and "counterion" is used to represent a small, negatively charged species such as chloride, bromide, hydroxide, acetate, sulfate and the like. As used herein, "aryl" or "aromatic residue" is intended to mean phenyl or naphthyl optionally substituted with 0-3 groups independently selected from methyl, methoxy, amino, hydroxy, halogen, Cι-C 6 alkoxy, Cι-C 6 alkyl, CF , S(0) m CH 3 , -N(CH 3 ) 2 - C1-C4 haloalkyl, methylenedioxydiyl, ethylenedioxydiyl; the term "arylalkyl" represents an aryl group attached through an alkyl bridge. As used herein, the term "heteroaryl" refers to aromatic heterocyclic groups. Such heteroaryl groups are preferably 5-6 membered monocylic groups or 8-10 membered fused bicyclic groups. Examples of such heteroaryl groups include, but are not limited to pyridyl (pyridinyl), pyrimidinyl, furanyl (furyl), t iazolyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, indolyl, isoxazolyl, oxazolyl, pyrazinyl, pyridazinyl, benzofuranyl, benzothienyl, benzimidazolyl, quinolinyl, or isoquinolinyl. As used herein, the term "chiral amine" refers to any amine containing compound that also contains a chiral center. Such compounds include, by way of example and without limitation, either enantiomer of cinchonidine, ephedrine, 2-phenylglycinol, 2-amino-3- methoxy-1-propanol, quinidine and pseudoephedrine. 2 ! As used herein, "pharmaceutically acceptable salts" refer to derivatives of the disclosed compounds wherein the parent compound of Formula I is modified by making acid or base salts of the compound of Formula I. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. "Prodrugs" are considered to be any covalently bonded carriers which release the active parent drug according to Formula I in vi vo when such prodrug is administered to a mammalian subject. Prodrugs of the compounds of Formula I are prepared by modifying functional groups present in the compounds in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compounds. Prodrugs include compounds of Formula I wherein hydroxyl, amino, sulfhydryl, or carboxyl groups are bonded to any group that, when administered to a mammalian subject, cleaves to form a free hydroxyl, amino, sulfhydryl, or carboxyl group respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups in the compounds of Formula I, and the like. Examples of the prodrug forms of the compounds of the present invention include the following esters: methyl; ethyl; isopropyl; methylcarbonyloxymethyl-; ethylcarbonyloxymethyl-; t-butylcarbonyloxymethyl-; cyclohexylcarbonyloxymethyl- , ■ 1- (methylcarbonyloxy) ethyl-,- 1- (ethylcarbonyloxy) ethyl- ,- 1- (t-butylcarbonyloxy) ethyl-; 1- (cyclohexylcarbonyloxy) ethyl-; i-propyloxycarbonyloxymethyl-; cyclohexylcarbonyloxymethyl- ; t-butyloxycarbonyloxymethyl- ; 1- (ι-propyloxycarbonyloxy) ethyl-; 1- (cyclohexyloxycarbonyloxy) ethyl- ; 1- (t-butyloxycarbonyloxy) ethyl-; dimethylammoethyl- ; diethylammoethyl-; (5-methyl-l, 3-dιoxacyclopenten-2-on- 4-yl)methyl-; (5- (t-butyl) -1, 3-dιoxacyclopenten-2-on- 4-y1 ) methyl- ; ( 1 , 3-dioxa-5-phenyl-cyclopenten-2-on-4- yl) methyl-; 1- (2- (2-methoxypropyl) -carbonyloxy) ethyl- . The pharmaceutically acceptable salts of the compounds of Formula I include the conventional non- toxic salts or the quaternary ammonium salts of the compounds of Formula I formed, for example, from non- toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoιc, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, lsethionic, and the like. The pharmaceutically acceptable salts of the present invention can be synthesized from the compounds of Formula I which contain a basic or acidic moiety by conventional chemical methods. Generally, the salts are prepared by reacting the free base or acid with stoichiometnc amounts or with an excess of the desired salt- forming inorganic or organic acid or base in a suitable solvent or various combinations of solvents. The pharmaceutically acceptable salts of the acids of Formula I can be formed with an appropriate amount of a base, such as an alkali or alkaline earth metal hydroxide e.g. sodium, potassium, lithium, calcium, or magnesium, or an organic base such as an amine, e.g., dibenzylethylenediamme, tri ethylamine, piperid e, pyrrolidine, benzylamme and the like, or a quaternary ammonium hydroxide such as tetramethylammoinum hydroxide and the like. As discussed above, pharmaceutically acceptable salts of the compounds of the invention can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid, respectively, in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington ' Pharmaceutical Sciences. 17th ed., Mack Publishing Company, Easton, PA, 1985, p. 1418, the disclosure of which is hereby incorporated by reference. The disclosures of all of the references cited herein are hereby incorporated herein by reference in their entirety. Synthesis The compounds of the present invention can be prepared in a number of ways well known to one skilled in the art of organic synthesis. The compounds of the present invention can be synthesized using the methods described below, together with synthetic methods known in the art of synthetic organic chemistry, or variations thereon as appreciated by those skilled in the art. Preferred methods include, but are not limited to, those described below. All references cited herein are hereby incorporated their entirety herein by reference. The following abbreviations are used herein: Boc tert-butyloxycarbonyl B0C 2 O di-tert-butyl dicarbonate Cbz benzyloxycarbony1 CDI 1, 1 '-carbonyldiimidazole DEC 1- (3-dimethylaminopropyl) -3- ethylcarbodiimide hydrochloride DIEA diisopropylethylamine DMAP 4-dimethylaminopyridine DMF N, N-dimethyl formamide EtOAc ethyl acetate EtOH ethyl alcohol pyr pyridine TBTU 2- (lH-Benzotriazol-l-yl)-l,l,3,3- tetramethyluronium tetrafluoroborate TFA trifluoroacetic acid THF tetrahydrofuran A convenient method for the synthesis of the compounds of this invention utilizes a dipolar cycloaddition of nitrones with appropriate dipolarophiles to the isoxazolidine rings present in compounds of Formula I (for a review of 1,3 -dipolar cycloadditions of nitrones, see Org. React. 36, 1, Confalone, et al) . Scheme I describes one synthetic sequence to the compounds of this invention. An appropriately substituted nitrile aldehyde (1-1) is treated with hydroxyamine in the presence of K2C03 in CH2C12 to give a nitrone(I-2) , which undergoes a 1,3-dipolar cycloaddtion to a suitably substituted alkene to afford the isoxazolidine (1-3) . Hydrolysis of the ester using conventional methods known to one skilled in the art of organic synthesis gives the desired acids. Intermediates containing alkali-sensitive functionality, such as nitrile, may be deesterified with excellent chemoselectivity using trimethylsilanolate according to the procedure of Laganis and Ehenard (Tetrahedron Lett. 1984, 25, 5831) . Coupling of the resulting acids to an appropriately substituted α- and β-amino ester using standard coupling reagents, such as DCC/HOBt, affords a nitrile-amide(I-3) . The nitrile is then converted to the amidine (1-4) via the imidate or thioimidate under standard conditions followed by ester saponification(LiOH, THF/H20) . Scheme I 1-1 1-2 An example of a related method of preparation for compounds of the present invention is illustrated in Scheme Ia. Conversion of 3- (4-cyanophenyl ) isoxazolidin- 5-ylacetate (Ia-l ) to the corresponding amidine , followed by protection as the Boc-derivative and saponif ication provides 3- (4-Boc-amidinophenyl ) isoxazolidin-5-ylacetic acid ( Ia-3 ) which is coupled with β-amino acid esters as 2 ά shown. Deprotection provides the desired isoxazolidinylacetyl-β-aminoalaninyl ester (Ia-5) . Saponification as described above gives the free acid. 2 - Scheme Ia Ia-1 Ia-2 Ia-3 Ia-4 Ia-5 The compounds of the present invention where X=CO is prepared by a reductive ring cleavage of the corresponding isoxazolidine with Zn/AcOH followed by a cycloaddition with DCI or phosgene . Scheme II shows the synthetic protocol . Scheme II 2 S π-i II-2 On treatment with zinc in aqueous HO Ac, the isoxasolidine(II-l) undergoes a reductive ring cleavage yielding 1, 3-aminoalcohol (II-2) , which is then converted to the cyclic carbamate(II-3) by DCI. Pinner transformation followed by hydrolysis furnishes the synthesis to give II-4. 2 C J Additional aldehydes useful for the preparation of compounds of the current invention can be prepared as illustrated in Scheme III below: Scheme TT.I A. B. Swern ox. Compounds of Formula I wherein Rl is R2HN(R2N=)CN(R2) - may be prepared by a transformation of the amine to the guanidine, which is brought about by using the method described by Kim, et al (Tetrahedron Lett. 1993, 48, 7677), shown in Scheme IV. 3θ Scheme IV Compounds of formula I wherein Rl is R2HNC(0)- may be prepared by reaction of the corresponding nitrile with an appropriate alcohol under acidic conditions (J. Med. Chem. 1991, 34, 851) or with hydrogen peroxide under basic conditions (J. Am. Chem. Soc. 1958. 80, 2257). Compounds of Formula I Wherein Rl is R2 (R50)N(R2N=)C- or R2HN(R50N=) C- may be prepared by reaction of the corresponding nitrile with an appropriately substituted hydroxyamine . The appropriately substituted racemic p-amino acids may be purchased commercially or, as is shown in Scheme II, Method 1, prepared from the appropriate aldehyde, malonic acid and ammonium acetate according to the procedure of Johnson and Livak (J. Am. Chem. Soc. 1936, 58, 299) . Racemic β-substituted-β-amino esters may be prepared through the reaction of dialkylcuprates or alkyllithiums with 4-benzoyloxy-2-azetidinone followed by treatment with anhydrous ethanol (Scheme I, Method 2) or by reductive a ination of β-keto esters as is described in WO9316038. (Also see Rico et al., J. Org. Chem. 1993, 5_8_, 7948-51.) Enantiomencally pure β- substituted-β-ammo acids can be obtained through the optical resolution of the racemic mixture or can be prepared using numerous methods, including: Arndt- Eistert homologation of the corresponding α-amino acids as shown in Scheme II, Method 3 (see Meier, and Zeller, Anαew. Chem. Int. Ed. Enσl. 1975, IA, 32; Rodriguez, et al. Tetrahedron Lett. 1990, H, 5153; Greenlee, J. Med. Chem. 1985, 23., 434 and references cited within); and through an enantioselective hydrogenation of a dehydroammo acid as is shown m Scheme II, Method 4 (see Asymmetric Synthesis, Vol. 5, (Morrison, ed.) Academic Press, New York, 1985) . A comprehensive treatise on the preparation of β-ammo acid derivatives may be found in patent application WO 9307867, the disclosure of which is hereby incorporated by reference. Scheme V Method 1 R* HO.C^.C0 2 H O 1 ) NH 4 OAc H,N C0 2 e R 4 R 8 -^H 2) MeOH, HO Method 2 Method 3 Method 4 The synthesis of N 2 -substιtuted diaminopropionic acid derivatives can be carried out via Hof fman rearrangement of a wide variety of asparagine derivatives as described in Synthesis, 266-267, (1981). The dipolarophiles used to prepare the compounds of this invention may be prepared by numerous methods. The ω-alkenoic ester class of dipolarophile may be purchased commercially or prepared by oxidation of the corresponding ω-alkenols by the method of Corey and Schmidt (Tetrahedron Let . 1979, 399, Scheme VI). Scheme VI The compounds of this invention and their preparation can be further understood by the following procedures and examples, which exemplify but which do not limit the invention. Example 1 Cis- 3 - 2 - r 2 -methvl -3 - f 4 - ( aminoiminomethyl ) phenyl i soxazol idin- 5 -yl l -acetyl 1 mino-N- ( 3 - methvl nhenvlsulfonvl ) -L-alanine mef.hvl ester monotrifluoroacetic acid Part A. C- (4-Cvanonhenvl ) -N-methyl nitrone A mixture of 4-cyanobenzaldehyde(3.3g, 25.2mmol), N-methylhydroxyamine hydrogen chloride and sodium bicarbonate (4.23g, 50.4mmol) in dry methylene chloride (8Oml) was stirred at rt for 5hrs. The solid portion was filtered off and the filtrate was concentrated to give the product as white solid(98%yield) . !H NMR(300MHz, CDCI3 )δ 3.94 (s, 3H) , 7.46(s, IH) , 7.72(d, J=8Hz, 2H) , 8.32(d, J=8Hz, 2H) MS(NH3-CI) Calc. for (M+l) + : 161. Found: 161. Part B. Isobntvl cis-2- ,2-mftr.hvl -3- ( ά- cvanophenvl) isoxazolidin- -vll acetate A solution of C- (4-cyanophenyl) -N-methylnitrone(lg, 6.3mmol) in vinyl acetate isobutyl este (10ml) was heated at 100 °C for 20hrs, and then concentrated. The residue was chromatographed with CH2C12/MeOH as eluent to give the cis isomer (880mg, 46% yield) and the trans(50mg, 2.6%), along with a cis and trans mixture ( 630mg, 33%). λ E NMR(300MHz, CDCI3 ) δO .90 (d, J=6, 6H) , 1.98(m, 2H), 2.60(m, IH) , 2. 62(s, 3H) , 2.90(m, 2H) , 3.68(t, J=5, IH) , 3.90(m, 2H) , 4.68(m, IH) ; MS(NH3-CI) Calc. for (M+l) + : 303. Found: 303. Part C. ri.q-2-r2-me hvl-3-(4- rvannnhpnvl ) soxazol i i n-5-vl l aret i r ar The above isobutyl acetate (850mg, 2.81 mol) was dissolved in aqueous THF (20ml, 1:1, v:v) containing LiOH.H2O(140mg, 3.3mmol). After stirring for 2hrs at rt, the solution was acidified with 2.81ml of IN HCl and concentrated. The residue was washed with a small amount of water and then dried to give the desired acid(630mg, 91%). !H NMR(300MHz, CDCI3 )δ2.18 (m, IH) , 2.68(s, 3H) , 2.70-3.18(m, 3H) , 3.80(t, J=6, IH) , 4.76(m, IH) , 7.60(d, J=8, 2H) , 7.76(d, J=8, 2H) . MS(ESI) Calc. for (M+l) + : 247. Found: 247. Part D. Me hvl N^-Cbz- -2. -d minonronionate HCl salt. N 2 -Cbz-L-2,3-diaminopropionic acid (10 mmol, 2.39 g) was dissolved in 20 mL methanol and 20 mL 4 N HCl in dioxane and the solution was stirred for 4 hours and then concentrated to give a solid. The solid was washed with ether several times to give 2.50 g (87%) product. i HNMR (DMSO-d 5 ): δ 8.38 (b, 3H) ; 7.96 (d, IH) ; 7.38 (m, 5H); 5.05 (s, 2H) ; 4.44 (m, IH) ; 3.66 (S, 3H) ; 3.14 (m, 2H) . Part E: Methvl N 2 --Cbz-N-Boc- -2.3-diaminonronionatP. To a solution of methyl N 2 -Cbz- (S) -2,3- diaminopropionate HCl salt (16.3 mmol, 4.7 g) and di- tert-butyl dicarbonate (16.3 mmol, 3.56 g) in 30 mL chloroform cooled in an ice bath was added triethylamine (34 mmol, 4.7 mL) and the solution was stirred in the ice bath for 1 hour and at room temperature for 3 hours and concentrated. The residue was taken up in ethyl acetate and the solution was washed with dilute citric acid, brine, NaHCOβ and brine, dried (MgS0 4 ) , and concentrated. Crystallization from ether/petroleum ether gave 5.2 g (92%) product. X HNMR (DMSO-dβ) : δ 7.60 (d, IH); 7.35 (m, 5H) ; 6.88 (t, IH) ; 5.02 (S, 2H) ; 4.14 (m, IH); 3.60 (s, 3H) ; 3.28 (m, 2H) ; 1.37 (s, 9H) . Part F: MPfhvl N^-Boc- (S) -2. -diaminopropionate Formic arid salt. A mixture of methyl N 2 -Cbz-N 3 -Boc- (S) -2, 3- dia inopropionate. (14 mmo, 5.0 g) , formic acid (42 mmol, 1.6 mL) and 10% Pd/C (500 mg) in 40 mL methanol was stirred at room temperature for 1 hour and filtered through a celite. The filtrate was concentrated and the residue was triturated with ether-petroleum ether to give 3.7 g (100%) solid product. 1HNMR (DMSO-d 6 ) : δ8.20 (s, IH); 6.90 (t, IH); 5.36 (b, 3H) ; 3.61 9s, 3H) ; 3.51 (t, IH) ; 3.18 (t, 2H); 1.38 (s, 9H) . Part G. 2 , 2-diaminQ p rQPionat.e. To a mixture of methyl N 3 -Boc- (S) -2, 3- dia inopropionate HCO 2 H salt (3.8g, 14.7mmol) and diisopropylethylamine(3.3g, 32.3mmol) in CH2CI2 (60ml) , cooled with ice-water, was added 3-methylsulfonyl chloride (3. lg, 16.2mmol). After stirring at rt for 24hrs, the resulting reaction mixture was diluted with ethyl acetate (150ml) , washed with dilute citric acid, saturated NaHCθ3 and brine, and then dried. Concentration afforded the product as a foam(5.1g, 95% yield). ±H. NMR(300MHz, CDCl3)δl.58 (s, 9H) , 2.30(s, 3H) , 2.72(m, IH) , 2.98(m, IH) , 4.10(m, IH) , 5,80(s, IH) , 7.40(d, J=5, 2H) , 7.50(m, IH) , 7.56(s, IH) , 8.40(d, J=6, IH); MS(NH3-CI) Calc. for (M+l) + : 373. Found: 373. Part H. Methvl N2-3-methvlnhPπvl sul fπnyl- (S) -2.3- iaminonroninnat.p HCl salt Methyl N 2 -3-methylphenylsulfonyl~N 3 -Boc- (S) -2, 3- diaminopropionate(4.5g, 12.1mmol) was dissolved in dioxane(δml) and then 4N HCl in dioxane(8ml) was added. The resulting solution was stirred at rt for 5hrs and then evaporated to give a foam(3.7g, 100% yield). 1 H NMR(300MHz, DMSO-d6)δ2.40 (s, 3H) , 2.86(m, IH) , 3.10(m, IH), 3.40(S, 3H), 4.28(m, IH) , 7.48(d,J=5 2H) , 7.60(m, IH), 7.62(S, IH) 8.39(s, broad, 2H) , 8.62(d, J=6, IH) ; MS (ESI) Calc. for (M+l) + : 273. Found: 273 (free base). Part I : CA s-3- \2- f 2-methvl - 3- ( 4-rvanonhenvl ) - i .qnya ol idin- S-vn acPtvn ami no-N- ( 3 - mpthvlphenvlsul fonvl ) -T,-a T an ine methvl pster To a mixture of cis-2 - [ 2 -methyl-3- ( 4- 3 * cyanophenyl) isoxazolidin-5-yl] acetic acid(600mg, 2.44mmol), methyl N 2 -3-methylphenylsulfonyl- (S) -2,3- diaminopropionate HCl salt(900mg, 2.9mmol) and triethylamine (1.18g, 11.7mmol) in DMF(lOml), cooled with ice-water, was added TBTU(940mg, 2.9mmol). After stirring for 3hrs, the reaction mixture was diluted with ethyl acetate and washed with dilute NaHC03 and brine, then dried. Concentration followed by chromatography with a mixture of methylene chloride and methanol as the eluent gave the product as an amorphous solid (1.2g, 99% yield) H NMR( 300MHz, CDCl3)δ2.04 (m, IH) , 2.40(, s, 3H) , 2.50(m, IH) , 2.60(m, IH) , 2.68 and 2.70(s, 3H) , 2.92 (m, IH), 3.59 and 3.61(s, 3H) , 3.61-3.80(m, 3H) , 4.04(m, IH), 4.60(m, IH) , 5.76 and 5.96(d, J=5, IH) , 6.60 and 6.70(t, J=3, IH) , 7.38-7.68(m, 8H) ; MS(NH3-CI) Calc. for (M+l) + : 501. Found: 501. Part J: Cis-3- r2-r2-metftyl-3-f4- (aminoiminomethyl ) phenvll - i .qoxazolidin-5-vl 1 acetyll ami no-N- (3- mPthv1nhpnvlsulfonvl)-T,-alaninp m thyl ps pr monotriflucroacetic acid Dry HCl gas was bubled through a solution of Cis-3- [2- [2-methyl-3- (4-cyanophenyl) -isoxazolidin-5- yl] acetyl] amino-N- (3-methylphenylsulfonyl) -L-alanine methyl ester (580mg 1.16mmol) in dry CHCI3 containing anhydrous methanol (55mg, 1.7mmol), cooled with salt ice- water bath, at 0 °C for 5hrs. The resulting solution was then kept at 0 °C for 6hrs and at 15 °C for 12hrs. The flammable portion was removed and the residue was dissolved in anhydrous methanol (8ml) followed by addition of ammonium bicarbonate (280mg, 2.91mmol). After stirring at rt for 4hrs, the mixture was concentrated and purified by flush chromatography over silica gel using a mixture of methylene chloride and methanol as the eluent to give a white amorphous solid (48Omg, 80% yield) . Further purification by reversed phase HPLC using water and 0.1% TFA in acetonitrile as eluent gave the TFA salt. !H NMR(300MHz, DMSO-dδ)δl .88 ( , IH) , 1.24(m, 2H) , 2.38(s, 3H) , 2.42 (m, IH) , 2.54(s, 3H) , 2.88(m, IH) , 3.17 (m, 2H) , 3.36(s, 3H) , 3.86 and 3.94 (t, J=6, IH) , 4.49(m, IH) , 7.42 (m, 2H) , 7.58 (m, 4H) , 7.84(d, J=7, 2H); MS(ESI) Calc. for (M+l) + : 518. Found: 518. E ample 2 Ci s-3- \7- r2-me hvl-3- 14- (aminni i nompthvl ) phenvl 1 - isoxazol idin-5-vll acetvll amino-N- (3- methvlphenvlsulfonvl ) -L-alanine monohvdroσenrhl r-i p Cis-3- [2- [2 -methyl -3- [4- (aminoiminomethyl ) phenyl ] - isoxazolidin-5-yl] -acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine methyl ester (lOO g, 0.19mmol) was dissolved in 3N HCl (3ml) . The resulting solution was stirred at rt for 36hrs and then concentrated to yield the acid as an amorphous solid (90mg, 90% yield) . The acid was further purified by reverse HPLC using water and 0.1% TFA in acetonitrile as eluent. !H NMR(300MHz, DMSO-d6)δ2.24 (m, IH) , 2.38(s, 3H), 2.54(s, 3H) , 2.60(m, IH) , 2.98(m, IH) , 3.08(m, IH) , 3.22(m,lH), 3.36(m, IH) , 3.86(m, IH) , 4.40(m,lH), 4.74(m, IH), 7.43 (m, 2H) , 7.38(m, 2H) , 7.80(d, J=7, IH) , 7.94(d, J=7, 2H) , 8.20(m, 2H) ; MS(ESI) Calc. for (M+l) + : 504. Found: 504. Example 3 Trans-3- 7- r2-mPthy1 -3- - (aminoiminomethyl) phenvll >S isoxazolidin-5-vl 1 cetvl 1 amino-N- ( - methvlphenvlsulfonvl) -L-alanine ethyl ester monotrifluoroacetic acid The same procedures used to prepare the cis isomer (Example 1) were adopted. λ R NMR( 300MHz, DMSO-d6 ) δ2.04-2.26 ( , 3H),2.30(s, 3H) , 2.44(m, IH) , 2.60(s, 3H) , 2.96(m, IH) , 3.10(m, 2H) , 3.40(s, 3H) , 3.80(m, IH) , 4.30(m, IH) , 7.42(m, 2H) , 7.50(m, 4H) , 7.88(d, J=7, 2H) ; MS(ESI) Calc. for (M+l)+: 518. Found: 518. Example 16 Ci s-3- \ 2 - r2-benzvl-3- f 4- (aminoiminomethyl )nhenv11 - lsoxazolidin-5-vl1acetvll-N-(3-methvlnhenvlsulfonyl)-T,- alanine methvl ester monotrifluoroacetic acid Part A. C- (4-Cvanophenvl ) -N-methylnitrone A mixture of 4-cyanobenzaldehyde(2.37g, lδ.lmmol), N-benzylhydroxya ine hydrogen chloride (3.47g, 21.7mmol) and sodium bicarbonate (3.65g, 43.4mmol) in dry methylene chloride (50ml) was stirred at rt overnight. The solid portion was filtered off and the filtrate was concentrated to give the product as white solid(97%yield) . ^-H NMR(300MHz, CDCl3)δ 5.20 (s, 2H) , 7.56(m, 6H) , 7.75(d, J=8Hz, 2H) , 8.40(d, J=8Hz, 2H) . MS(NH3-CI) Calc. for (M+l)+: 237. Found: 237. Part B. Isobutvl cis-2- r2-benzvl-3- (4- cvanophenvl ) isoxazolidin-5 -vll cetate A solution of C- (4-cyanophenyl) -N- benzylnitrone(2.5g, 10.6mmol) in vinyl acetate isobutyl 3 ester (15ml) was heated at 100 °C overnight, and then concentrated. The residue was chromatographed using a mixture of ethyl acetate and hexane as eluent to give the cis iso er (3.04g, 76% yield) and a mixture of the cis and trans isomers ( 360mg, 9%). ^-E NMR(300MHz, CDCl3)δ0.88(d, J=6, 6H) , 1.86(m, IH) , 1.98(m, IH) , 2.56 (dd, J=13 and 6, IH) , 2.80 (dd, J=ll and 6, IH) . 2.99(m, IH) , 3.84(d, J=6, 2), 3.92(s, 2H) , 3.98(t, J=6.5, IH) , 4.68(m, IH) , 7.24(m, 5H) , 7.48(d, J=7, 2H) , 7.58(d, J=7, 2H); MS(NH3-CI) Calc. for (M+l)+: 379. Found: 379. Part C. Cis-2-f2-benzyl-3-(4- cvanophenvl) isoxazolidin-5-yll acetic acid The above isobutyl acetate (1.15g, 3.0mmol) was dissolved in aqueous THF (20ml, 1:1, v:v) containing LiOH.H2O(140mg, 3.3mmol). After stirring overnight at rt, the solution was evaporated to dryness. The residue was taken up in 60ml of ethyl acetate and washed with water, then dried. Removal of ethyl acetate gave the product as an oil(850mg, 88%yield) . X H NMR(300MHz, CDCl3)δ2.16(m, IH) , 2.78(dd, IH) , 2.96(dd, IH) , 3.10(m, IH), 4.02(s, 2H), 4.12(t, IH) , 4.78(m, IH) , 7.34(m, 5H) , 7.60(d, 2H) , 7.70(d, 2H) ; MS(ESI) Calc. for (M+l)+: 323. Found: 323. Part D: Cis-3- \ 2- r2-benzvl-3- (4-cvanophenvl) - isoxazolidin-5-vl1 cetvl1 amino-N- (3- methylphenylsulfonyl) -L-alanine methvl ester To a mixture of cis-2- [2-benzyl-3- (4- cyanopheny1) isoxazolidin-5-y1] acetic acid( 1. og, 3.10mmol), methyl N 2 -3-methylphenylsulfonyl- (S) -2, 3- diaminopropionate HCl salt(1.05g, 3.4mmol) and triethylamine (1.9ml, 13. δmmol) in DMF (12ml), cooled with ice-water, was added TBTUd.lOg, 3.4mmol). After stirring for 3hrs, the reaction mixture was diluted with ethyl acetate and washed with dilute NaHCθ3 and brine, then dried. Concentration followed by chromatography with a mixture of methylene chloride and methanol as the eluent gave the product as an amorphous soli (1.76g, 99% yield). MS(NH3-CI) Calc. for (M+l) + : 577. Found: 577. Part E: Cis-3- f2-r2-benzyl-3-r4- Iami noi mi nompthvl ) phpnvl 1 - i soxazolidin- -vll cetvπ amino-N- ( - mpthylphenylsulfonvl) -L-alanine methvl ester monotrifluoroacetic arid Dry HCl gas was bubled through a solution of Cis-3- [2- [2-benzyl-3- (4-cyanophenyl) -isoxazolidin-5- yl ] acetyl] amino-N- (3 -methylphenylsulfonyl ) -L-alanine methyl ester (510mg 1.13mmol) in dry CHCI3 containing anhydrous methanol (53mg, 1.7mmol), cooled with salt ice- water bath, at 0 °C for 5hrs. The resulting solution was then kept at 0 °C for 6hrs and at 15 °C for 12hrs. The flammable portion was removed and the residue was dissolved in anhydrous methanol ( 8ml ) followed by addition of ammonium bicarbonate ( 27Omg, 2.82mmol). After stirring at rt for 4hrs, the mixture was concentrated and purified by flush chromatography over silica gel using a mixture of methylene chloride and methanol as the eluent to give a white amorphous solid (500mg, 95% yield) . Further purification by reversed phase HPLC using water and 0.1% TFA in acetonitrile as eluent gave the TFA salt. 1 H NMR(300MHz, CDCI3 )δ2.04 (m, IH) , 2.26(m, IH), 2.40(s, 3H), 2.60(m, IH) , 2.96(m, IH) , 3.40(m, IH) , 3.54 and 3.60(s, 3H) , 3.90-4.14(m, 2H) , 4.74(m, IH) , 7.10(m, IH), 7.20-7.46(m, 8H) , 7.58(m, 2H) , 7.74(m, 2H) , 7.90(m, IH) ; MS(ESI) Calc. for (M+l) + : 594. Found: 594. Example 17 Cis-3- f2- r2-benzvl-3- \ - (aminoiminomethyl ) phenyl! - isoxazolidin-5-vllacetyll amino-N- (3- methvlphenvlsulfonvl) -L-alanine monohvdroaenchlori.de This was prepared analogously to Example 2. λ E NMR( 300MHz, DMSO-d6 ) δl .82 (m, IH) , 2.24(m, IH) , 2.34 and 2.36(s, 3H) , 2.42(m, IH) , 3.04(m, IH) , 3.22(m, IH) , 3.40(m, IH) , 3.50(m, 2H) , 3.88(m, IH) , 4.64(m, 2H) , 7.08(d, J=6, 2H) , 7.24-7.60(m, 9H) , 7.88(m, 2H), 8.16(m, IH) , 8.26 (m, IH) ; MS (ESI) Calc. for (M+l)+: 580. Found: 580. Example 28 Cis-3- \ 2 - r2-isopropvl-3- (4- (aminoiminomethyl ) phenyl " isoxazolidin-5-vl 1 acetvl 1 amino-N- ( 3 - methvlphenvlsulfonvl) -L-alanine ethyl ester monotrifluoroacetic acid This compound was prepared analogously to Example 1. X H NMR(300MHz, CDCI3 ) δ 1.02 (m, 3H), 1.14(m, 3H) , 2.05(m, IH) , 2.46(s, 3H) , 2.48-70(m, 2H) , 2.94-3.16(m, 2H), 3.47(m, IH) , 3.58(s, 3H) , 3.78(m, IH) , 4.14(m, IH) , 4.40(m, IH) , 4.66(m, IH) , 4.90(m, IH) , 7.30(m, IH) , 7.40(m, 2H) , 7.64(d, J=7, 2H) , 7.76(s, 2H) , 7.92(d, J=7 , 2H) ; MS (ESI) Calc. for (M+l)+: 546. Found: 546. Exampl 29 Cis-3- \ 2 - f2-isopropyl-3- T4- (aminoiminomethyl) phenvl1 - isoxazolidin-5-vllacetvll amino-N- (3- methylphenvlsulfonvl) -L-alanine monohydrogenchloride This compound was analogously prepared to Example 2. X H NMR( 300MHz, DMS0-d6 ) δl .12 (m, 3H) , 1.16(m, 3H) , 2.10(m, IH), 2.40(s, 3H) , 2.50-68(m, 2H) , 2.93-3.24(m, 2H) , 3.38(m, IH) , 3.86 (m, IH) , 4.20(m, IH) , 4.38(m, IH) , 4.60(m, IH) , 4.96(m, IH) , 7.26(m, IH) , 7.44(m, 2H) , 7.66(d, J=7, 2H) , 7.80(s, 2H) , 7.90(d, J=7, 2H) ; MS(ESI) Calc. for (M+l) + : 532. Found: 532. Example 32 Cis-3- \2 - r2-methvl-3- T4- (aminoimi nomethvl ) phenvl 1 i soxazolidin- -vll acetvl 1 ami no-N- ( 2 - methvlphenvlsulfonvl) -L-alanine methyl ester monotrifluoroacetic acid This compound was analogously prepared to Example 1. X H NMR(300MHz, DMS0-d6 ) δl .80 ( , IH) , 1.26(m, 2H) , 2.34(s, 3H) , 2.40(m, IH) , 2.44(s, 3H) , 2.86(m, IH) , 3.14(m, 2H) , 3.38(s, 3H) , 3.84 and 3.92(t, J=6, IH) , 4.40(m, IH) , 7.48(m, 2H) , 7.56(m, 4H) , 7.80(d, J=7, 2H) MS(ESI) Calc. for (M+l) + : 518. Found: 518. Example 33 ri,q-3- r2-r2-methvl-3-r4- (aminoimi nnmer.hvl ) phenvl 1- isoxazolidin-5-vll cetvl 1 ami no-N- (2- methvlphenvlsulfonvl ) -L-alanine monohydrogenchloride This compound was analogously prepared to Example 2. iH NMR( 300MHz, DMSO-d6 )δ 2.20 (m, IH) , 2.42(m, IH) , 2.63(s, 3H) , 2.66(s, 3H) , 2.72(m, IH) , 2.96(m, IH) , 3.60(m, 2H) , 3,71(m, IH) , 4.02(m, IH) , 4.66(m, IH) , 7.32(d, J=5, 2H) , 7.50(m, 3H) , 7.64(m, 2H) , 7.92(d, J=6, IH); MS (ESI) Calc. for (M+l) + : 504. Found: 504. Exampl e 37 Cis-3- r2- f2-methvl-3-r4- (aminoiminomethyl ) phenvl 1- isoxazolidin-5-vll acetvll amino-N- (3.5-di er.hvloxazol -4- vl nlfonvl ) -L-alanine methvl ester onotri f1 uoroacet.i r acid This compound was analogously prepared to Example 1. !H NMR( 300MHz, DMS-d6 ) δl .88 (m, IH) , 1.28(m, IH) , 2.32(s, 3H), 2.47(m, IH) , 2.52(s, 3H) , 2.54(s, 3H) , 2.90(m, IH) , 3.27(m, IH) , 3.36(s, 3H) , 3.87(m, IH) , 3.96(m, IH), 4.14 ( , IH) , 4.52(m, IH) , 7.60(d, J=7, 2H) , 7.84 (d, J=7, 2H); MS (ESI) Calc. for (M+D + : 523. Found: 523. Ex le 8 Ci s-3- \ 2 - r -methvl-3- U- (aminoiminomethyl ) nhenvll - i oxazol i in-5-vl 1 cetvll mino-N- ( .5-dimethv oxazol -4- ylsπlfonyl)-T,-a1an ne monohvdroπenrhloride This compound was analogously prepared to Example 2. 1 H NMR( 300MHz, DMSO-d6 ) δ2.32 (m, IH) , 2.52 and 2.53(s, 3H), 2.56 and 2.57(s, 3H) , 2.74(m, 2H) , 2.82(s, 3H) , 3.03(m, IH) , 3.15(m, IH) , 2.30(m, IH) , 3.44(m, IH) , 3.92(m, IH) , 4.88 (m, IH) , 7.88(d, J=6, 2H) , 7.94(d, J=6, 2H) , 8.36(m, IH) , 8.61(m, IH) ; MS(EΞI) Calc. for (M+l) + : 509. Found: 509. Example 8 Cis- -r2-r2-methvl-3 -r4- (aminoiminomethyl) phenvl1 - isoxazolidin-5-vπ acetvll amino-N-n-butyloxycarbonyl-T,- alanine methyl ester monotrifluoroacetic acid This compound was prepared analogously to Example 1. 3-H NMR(300MHz, DMS0-d6)δ 0.84 and 0.86(t, J=5, 3H) , 1.31(m, 2H), 1.48(m, 2H) , 1.92(m, IH) , 2.36(m, IH) , 2.50(, s, 3H), 2.52(m, IH) , 3.28(m, IH) , 3.36(s, 3H) , 3.44(m, IH) , 3.90(m, 3H) , 4.12(m, IH) , 4.56(m, IH) , 7.46(d, J=5, IH), 7.60(d, J=7, 2H) , 7.84(d, J=7, 2H) , 8.19(m, IH) ; MS(ESI) Calc. for (M+D + : 464. Found: 464. Example 69 Cis-3- F2- r2-methvl-3-f4- (aminoiminomethyl) phenyl 1 - isoxazolidin-5-vll acetyll amino-N-n-butyloxycarbonyl-L- alanine monohydrogenchloride This compound was prepared analogously to Example 2. X H NMR(300MHz, DMSO-d6 ) δO .93 (t , J=5, 3H) , 1.26(m, 2H) , 1.46(m, 2H) , 2.30(m, IH) , 2.59(m, IH) , 2.74(s, 3H) , 2.98(m, IH) , 3.20(m, IH) , 3.36(m, IH) , 3.45(m, IH) , 3.88(m, 3H), 4.03(m, IH) , 4.80 (m, IH) , 7.28(d, J=5, IH) 7.82(d, J=7, 2H) , 7.7.90(d, J=7, 2H) , 8.22(m, IH) ; MS(ESI) Calc. for (M+l)+: 450. Found: 450. Example 7Q Cis-3- \ 2 - r2-phenvl-3- (4- (aminoiminomethyl) phenvl 1 - isoxazolidin-5-vll cetvll mino-N- (3- ethvlphenvlsulfonvl) -L-alanine methyl ester monotrifluoroacetic acid This compound was prepared analogously to Example 1. X H NMR( 300MHZ, DMSO-d6 ) δ2.10 (m, IH) , 2.40(s, 3H) , 2.50- 2.68(m, 2H),3.02(m, IH) , 3.60(m, 2H) , 4.00(m, IH) , 4.64(m, IH), 4.86(m, IH) , 5.71(m, IH) , 6.40(m, IH) , 6.98(m, 3H) , 7.26(m, 3H) , 7.38(d, J=3, 2H) , 7.64 (m, 5H) MS(ESI) Calc. for (M+l) + : 580. Found: 580. Example 71 Cis-3- r -r2-phenvl-3- r 4- (aminoiminomethyl ) phenyl 1- isQxasQlidin-5-γll cetvll mino-N- (3- ethvlphenvlsulfonvl ) -I,-alanine monohvdroαenrhl ori de This compound was prepared analogously to Example 2. ■ LR NMR(300MHz, DMSO-d6)δ2.20 (m, IH), 2.40(s, 3H) , 2.51(m, IH) , 2.62(m, IH) , 3.04(m, IH) , 3.60(m, 2H) , 4.00(m, IH) , 4.64(m, IH) , 4.84(m, IH) , 5.68(d, J=6, IH) 6.40(m, IH) , 6.96(m, 3H) , 7.20-7.40(m, 4H) , 7.62(m, 6H) MS(ESI) Calc. for (M+l) + : 566. Found: 566. Example 300 Cis-3- r r T4-r4- (aminoiminomethyl) phenvl 1 tetrahvdro-3- methvl- -oxo-2H-1.3-oxazin-6-vllacetv1 l minol-N-f (3- methvl phenvl )sulfonvl1 -L-alanine methvl ester monotrifluoroacetic acid Part A. Ci -3- r r U- (4-cvanonhenv ) tetrahvdro-3-methvl -2- X -2H-1. -oxazin-6-vll acetyl laminol -N- \ (3- methvl phenvl )sulfonvl1 -L-al nine methvl ester monotri f1 uoroacetic acid Cis-3- [2- [2-methyl-3- (4-cyanophenyl ) -isoxazolidin-5- yl] acetyl] amino-N- (3-methylphenylsulfonyl) -L-alanine methyl ester (600mg, 1.2mmol) was dissolved in aqueous acetic acid(16ml, v:v, 1:1) and zinc(1.17g, 18mmol) was added. The resulting suspension was stirred vigorously at rt for 2hrs, then was filtered. The filtration was evaporated to dryness. The residue was dissolved in aqueous NaHCO3(10ml) and the cloudy solution was evaporated to dyness again. The remaining solid was extracted with ethyl acetate. Removal of ethyl acetate gave the 1, 3-aminoalcohol as an oil, which was directly used in the next reaction. The above 1, 3-aminoalcohol (480mg, 0.96mmol) was dissolved in anhydrous THF (10ml) and CDI(170mg, l.Oδmmol) was added. The solution was stirred at rt for 4 hrs. After evaportation, the residue was taken up in ethyl acetate (100ml) . The ethyl acetate solution was washed successively with IN HCl, dilute NaHC03 and brine, and the dried over Na2S04. Evaporation followed by chromatography using a mixture of ethyl acetate and hexane gave the product as an amorphous solid (450mg, 71% yield after two steps). λ n NMR(300MHz, CDCI3) δ2.00(m, IH) , 2.40(s, 3H) , 2.50(m, IH) , 2.60(m, IH) , 2.68 and 2.70(s, 3H) , 2.92 ( , IH) , 3.59 and 3.61(s, 3H) , 3.61-3.80 (m, 3H) , 4.04(m, IH) , 4.60(m, IH) , 5.76 and 5.96(d, J=5, IH) , 6.60 and 6.70(t, J=3, IH) , 7.38- 7.68(m, 8H) ; MS (ESI) Calc. for (M+D + : 531. Found: 531. (a inoim nomethvl) phenvl 1 tetrahvdro-3-methvl - -OXO-2H- 1.3-oxazin-6-vl1 cetvll aminol-N-r (3- methvlphenvDsulfonvll -L-alanine methvl ester monotrifluoroacetic acid Dry HCl gas was bubled through a solution of Cis-3- [ [ [4- (4-cyanophenyl) tetrahydro-3-methyl-2-oxo-2H-l, 3- ? oxazm-6-yl] acetyl] ammo] -N- [ (3-methylphenyl) sulfonyl] - L-alanme methyl ester monotrifluoroacetic acιd(510mg 0.96mmol) in dry CHCI3 containing anhydrous methanol (47mg, 1.44mmol), cooled with salt ice-water bath, at 0 °C for 5hrs. The resulting solution was then kept at 0 °C for 6hrs and at 15 °C for 12hrs. The flammable portion was removed and the residue was dissolved m anhydrous methanol (5ml) followed by addition of ammonium bicarbonate (23Omg, 2.4mmol). After stirring at rt for 4hrs, the mixture was concentrated and purified by flush chromatography over silica gel using a mixture of methylene chloride and methanol as the eluent to give a white amorphous solid (500mg, 95% yield) . Further purification by reversed phase HPLC using water and 0.1% TFA in acetonitrile as eluent gave the TFA salt. X H NMR(300MHz, CDCI3 ) δ2.14 (m, IH) , 2.30(m, IH), 2.40(s, 3H), 2.67(111, IH) , 2.86(m, IH) , 3.40 (m, IH) , 3.54 and 3.60(s, 3H) , 3.90-4.14(m, 2H) , 4.74(m, IH) , 7.10(m, IH) , 7.20-7.46(m, 8H) , 7.58(m, 2H) , 7.74 ( , 2H) , 7.90(m, IH); MS (ESI) Calc. for (M+l) + : 546. Found: 546. Example 301 Ci s-3- r r T4- T4- (aminoiminomethyl ) phenvl1 etrahvdro-3- methvl -2-oxo-2H-l . -oxazι n-6-vl 1 acetvll am ol -N- f (3- methvlphenvDsulfonvll -L-alanme monohydrogenchloride Cιs-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl] acetyl] amino] -N- [ (3- methylphenyl) sulfonyl] -L-alanme methyl ester (30mg, 0.06mmol) was dissolved in 3N HCl (3ml). The resulting solution was stirred at rt for 36hrs and then concentrated to yield the acid as an amorphous solιd(90mg, 90% yield) . The acid was further purified by reverse HPLC using water and 0.1% TFA in acetonitrile as eluent. MS (ESI) Calc. for (M+l) + : 532. Found: 532. ? Example 321 Cis-3- f r T4-r4- (aminoiminomethyl ) ohenyll tetrahvdro- - benzvl-2-oxo-2H-l,3-oxazin-6-vn acetyll amino1 -N- f (3- met.hylphenvDsulfonvll -L-alanine methyl ester monotrifluoroacetic acid This compound was synthesized analogously to Example 300. λ E NMR(300MHz, DMSO-d6 ) δl .98 (m, IH) , 2.34(m, IH) , 2.44(s, 3H) , 2.60(m, 2H) , 3.56(m, 5H) , 3.70(m, 2H) , 4.08(m, 2H), 4.40(m, IH) , 5.30(m, IH) , 6.10(d, IH) , 7.24-7.40(m, 6H) , 7.64 (m, 3H) ; MS(ESI) Calc. for (M+l)+: 622. Found: 622. Example 322 Cis-3- r r 14- f4- (aminoiminomethyl) phenvl 1tetrahvdro-3- benzyl-2-oxo-2H-1.3-oxazin-6-yll acetvll aminol-N- r (3- methylohenvl ) sulfonvll -L-alanine monohydrogenchloride This compound was analogously prepared to Exampl 301. λ K NMR( 300MHz, DMSO-d6 ) δ2.02 (m, IH) , 2.33(m, IH) , 2.40(s, 3H) , 2.66(m, 2H) , 3.45(m, 2H) , 3.70(m, 2H) , 4.10(m, 2H), 4.44(m, IH) , 5.20(m, IH) , 6.15(d, IH) , 7.20-7.40(m, 6H) , 7.60(m, 3H) ; MS(ESI) Calc. for (M+l) + : 608. Found: 608. Example 327 Cis-3- f r T4- \ 4- (aminoiminomethyl ) nhenylT tetrahvdro-3- methyl-2-oxo-2H-l.3-oxazin-6-vl1 acetyll amino1 -N- r (2- methylphenvl) sulfonvll -L-alanine methyl ester monotrifluoroacetic acid This compound was analogously prepared to Example 300 !H NMR(300MHz, DMS0-d6 )δl .80 (m, IH) , 2.40(m, 2H) , 2.58(s, 3H) , 2.64(m, 4H) , 3.44(m, 4H) , 3.56(m, IH) , 3.92(m, IH) , 4.50(m, IH) , 4.70 (m, IH) , 6.98(t, IH) , 7.20-7.40(m, 4H) , 7.60-7.80(m, 4H) ; MS(ΞSI) Calc. for (M+l) + : 546. Found: 546. Example 328 Cis-3- r r r4- - (aminoiminomethyl ) nhenyl 1 tetrahvdro-3- methvl-2-oxo-2H-l,3-oxazin-6-vl 1 acetvll aminol-N-f ( ?. - methvlphenvl) sulfonvll -L-alanine monohydrogench oride This compound was analogously prepared to Example 301. X H NMR( 300MHz, DMSO-d6 ) δl .90 ( , IH) , 2.44(m, 2H) , 2.60(s, 3H) , 2.66(m, 4H) , 3.39(m, IH) , 3.58(m, IH) , 3.90(m, IH) , 4.52(m, IH) , 4.68(m, IH) , 6.80(t, IH) , 7.18-7.40(m, 4H), 7.62-7.84(m, 4H) ; MS(ESI) Calc. for (M+l) + : 532. Found: 532. Example 335 Ci -3- r r r4-T - (aminoiminomethyl ) henvl 1 etrahvdro- - methyl -2-oxo-2H-1.3-oxazin-6-vl 1 cetvl 1 a inol -N- r (3.5- di ethvl lsoxazol-4-vl ) ul fonvl 1 -L-alanine methvl ester monotrifluoroacetic acid This compound was analogously prepared to Example 300. !H NMR( 300MHz, DMSO-d6 )5l .88 (m, IH) , 2.34(s, 3H) , 2.38- 2.50(m, 9H) , 3.20(m, 4H) , 3.40(m, IH) , 3.98(m, IH) , 4.70 (m, 2H), 7.50(d, J=8, 2H) , 7.88(d, J=8, 2H) ; MS (ESI! Calc. for (M+l) + : 551. Found: 551. Example 336 90 Cis-3- r f f4- T4- (aminoiminomethyl Iphenvll tetrahvdro-3- methvl-2-oxo-2H-l. -oxazin-6-vll acetvll aminol-N-f (3, 5- dimethvlisoxazol-4-vl ) sulfonvll -L-alanine monohydrogenchloride This compound was analogously prepared to Example 301. 3-H NMR( 300MHz, DMSO-d6 ) δ2.10 (m, IH) , 2.40(s, 3H) , 2.44- 2.60(m, 9H), 3.20(m, IH) , 3.46(m, IH) , 3.42(m, IH) , 4.80(m, 2H) , 7.84(d, J=8, 2H) , 7.98(d, J=8, 2H) ; MS(ESI) Calc. for (M+l)+: 537. Found: 537. Example 355 Cis-3- f r f4- T4- (aminoiminomethyl) nhenvll etrahvdro- - methvl-2-oxo-2H-l, 3-oxazin-6-vll acetvll ami nol -N- (n- butvloxvcarbonvl) -L-alanine methyl ester monotrifluoroacetic acid This compound was analogously prepared to Example 300. λ E NMR( 300MHz, DMSO-d6)δθ .80 ( , J=6, 3H) , 1.34(m, 2H) , 1.50(m, 2H) , 1.90(m, IH) , 2.40(m, 4H) , 2.56(s, 3H) , 3.40(s, 3H) , 3.80(m, 2H) , 3.92(m, 2H) , 4.14(m, 2H) , 4.70(m, IH), 7.50(d, J=8, 2H) , 7.90(d, J=8, 2H) ; MS(ESI) Calc. for (M+D + : 492. Found: 492. Example 355 Cis-3- r r \4- \4- (aminoiminomethyl ) nhenvll tetrahvdro-3- methvl-2-oxo-2H-1.3-oxazin-6-vll acetvll aminol-N- (n- butvloxvcarbonvl) -L-alanine monohydrogenchloride This compound was analogously prepared to Example 301. λ E NMR( 300MHz, DMSO-d6 )δθ .86 (t, J=6, 3H) , 1.40(m, 2H) , 1.56(m, 2H) , 1.94(m, IH) , 2.45(m, 4H) , 2.62(s, 3H) , 3.78(m, 2H) , 3.96(m, 2H) , 4.18(m, 2H) , 4.68(m, IH) , 7.78(d, J=8, 2H) , 7.98(d, J=8, 2H) ; MS(ESI) Calc. for (M+l) + : 478. Found: 478. The previous working examples are shown in Table 1 along with other examples of compounds of the invention which can be prepared by the schemes and procedures discussed above or variations thereof which are obvious to those skilled in the art using appropriate starting materials. Table 1 Ex No. R^Ar m R3 R5 RU MS [(M+l) + ] 1 4-amidinophenyl 0 Me none H 3-methylphenylsulsonyI OMe 518 2 4-amidinophenyl 0 Me none H 3 -methylphenylsulfonyl OH 504 3* 4-amidinophenyl 0 Me none H 3-methylphenylsulfonyl OMe 518 4-amidinophenyl 0 Ethyl none H 3- methylphenylsulfonyl OMe 5 4-amidinophenyl 0 Ethyl none H 3-methylphenylsulfonyl OH 6 4-amidinophenyl 0 n-propyl none H 3 -methylphenylsulfonyl OMe 7 4-amidinophenyl 0 n-propyl none H 3-methylphenylsulfonyl OH 8 4-amidinophenyl 0 n-butyl none H 3-methylphenylsulfonyl OMe 9 4-amidinophenyl 0 n-butyl none H 3 -methylphenylsulfonyl OH 10 4-amidinophenyl 0 n-hexyl none H 3 -methylphenylsulfonyl OMe 11 4-amidinophenyl 0 n-hexyl none H 3-methylphenylsulfonyl OH 12 4-amidinophenyl 0 Me none Me 3-methylphenylsulfonyl OMe 13 4-amidinophenyl 0 Me none Me 3-methylphenylsulfonyl OH 14 4-amidinophenyl 0 Me none ethyl 3- methylphenylsulfonyl OMe 15 4-amidinophenyl 0 Me none ethyl 3-methylphenylsulfonyl OH 16 4-amidinophenyl 0 benzyl none H 3-methylphenylsulfonyl OMe 594 17 4-amidinophenyl 0 benzyl none H 3- methylphenylsulfonyl OH 580 18* 4-amidnophenyl 0 benzyl none H 3-methylpheπylsulfonyl OH 19 (N-methylamidino) 0 Me none H 3-methylphenylsulfonyl OH phenyl 0 4-(N-methylamidino) 0 Me none Me 3- methylphenylsulfonyl OH phenyl 1 4-(N-ethylamidino) 0 Me none Me 3-methylpheπylsulfonyl OH phenyl 2 4-(N-methylamidino) 0 Me none ethyl 3-methylphenylsulfonyl OH phenyl 3 (N-methylamidino) 0 ethyl none Me 3-methyIphenylsulfonyl OH phenyl 4 4-(N-methylamidino) 0 ethyl none Me 2-methylphenylsulfonyl OH phenyl 5 4-(N-methylamidino) 0 ethyl none Mc 4-methylphenylsulfonyl OH phenyl 6 4-amidinophenyl 0 benzyl none 7 4-amidinophenyl 0 benzyl none 8 4-amidinophenyl 0 isopropyl none 546 9 4-amidinopbenyl 0 isoprop l none 532 0 4-amidinophenyl 0 isopropyl none 1 4-amidinophenyl 0 isopropyl none 2 4-amidinophenyl 0 Methyl none 518 3 4-amidinophenyl 0 Methyl none 504 4 4-amidinophenyl 0 Methyl none 5* 4-amidinophenyl 0 Methyl none 6* 4-amidinophenyl 0 Methyl none 7 4-amidinophenyl 0 Methyl none 523 8 4-amidinophenyl 0 Methyl none 509 9* 4-amidinophenyl 0 Methyl none S 3 ss Sέ 184 4-amidinophenyl 0 n-hexyl none 1 H 2-pyridylmethoxy- OH carbonyl 185 4-amidinophenyl 0 n-hexyl none 1 H 3-pyridylmethoxy- OH carbonyl 186 4-amidinophenyl 0 n-hexyl none 1 H 4-pyridylmethoxy- OH carbonyl 187 4-amidinophenyl 0 n-hexyl none 1 H styrylsulfonyl OH 188 4-amidinophenyl 0 phenyl none 1 H n-butyloxycarbonyl OH 189 4-amidinophenyl 0 phenyl none 1 H methyloxycarbonyl OH 190 4-amidinophenyl 0 phenyl none 1 H ethyloxycarbonyl OH 191 4-amidinophenyl 0 phenyl none 1 H methyloxycarbonyl OH 192 4-amidinophenyl 0 phenyl none 1 H n-pentyloxycarbonyl OH 193 4-amidinophenyl 0 phenyl none 1 H n-hexyloxycarbonyl OH 194 4-amidinophenyl 0 phenyl none 1 H H OH 195 4-amidinophenyl 0 phenyl none 1 H phenylethyloxycarbonyl OH 196 4-amidinophenyl 0 phenyl none 1 H 2,2-dimethylpropyl- OH carbonyl 197 4-amidinophenyl 0 phenyl none phenylethylcarbonyl OH 198 4-amidinophenyl 0 phenyl none n-pentylcarbonyl OH 199 4-amidinophenyl 0 phenyl none n-butylcarbontyl OH 200 4-amidinophenyl 0 phenyl none propionyl OH 201 4-amidinophenyl 0 phenyl none acetyl OH 202 4-amidinophenyl 0 phenyl none methylsulfonyl OH 203 4-amidinophenyl 0 phenyl none ethylsufonyl OH 204 4-amidinophenyl 0 phenyl none n-butylsulfonyl OH 205 4-amidinophenyl 0 phenyl none phenylsulfonyl OH 206 4-amidinophenyl 0 phenyl none benzylsulfonyl OH 207 4-amidinophenyl 0 phenyl none 2-pyridylcarbonyl OH 208 4-amidinophenyl 0 phenyl none 3-ρyridylcarbonyl OH 209 4-amidinophenyl 0 phenyl none 4-pyridylcarbonyl OH 210 4-amidinophenyl 0 phenyl none 2-pyridylmethylcarbonyl OH 211 4-amidinophenyl 0 phenyl none 3-pyridylmeuιylcarbonyI OH 213 4-amidinophenyl 0 phenyl none 4-pyridylmethylcarbonyl OH 214 4-amidinophenyl 0 phenyl none 1 H 2-pyridylmethoxy- OH carbonyl 215 4-amidinophenyl 0 phenyl none 1 H 3-pyridylmethoxy- OH carbonyl 216 4-amidinopbenyl 0 phenyl none 1 H 4-pyridylmethoxy- OH carbonyl 217 4-amidinophenyl 0 phenyl none 1 H styrylsulfonyl OH 218 4-(N-methylamidino) 0 Me none 1 H n-butyloxycarbonyl OH phenyl 219 4-(N-methylamidino) 0 Me none 1 H methyloxycarbonyl OH phenyl 220 4-(N-methylamidino) 0 Me none 1 H ethyloxycarbonyl OH phenyl 221 (N-methylamidino) 0 Me none 1 H methyloxycarbonyl OH phenyl 222 4-(N-methylamidino) 0 Me none 1 H n-pentyloxycarbonyl OH phenyl 223 4-(N-methylamidino) 0 Me none 1 H n-hexyloxycarbonyl OH phenyl 224 4-(N-methylamidino) 0 Me none 1 H H OH 5?- 5S 5 CO έ\ < <G Utility The compounds of this invention possess antiplatelet efficacy, as evidenced by their activity in standard platelet aggregation assays or platelet fibrinogen binding assays, as described below. A compound is considered to be active in these assays if it has an IC50 value of less than about 1 mM. Platelet aggregation and fibrinogen binding assays which may be used to demonstrate the antiplatelet activity of the compounds of the invention are described below. Platelet Aggregation Assay : Venous blood was obtained from the arm of a healthy human donor who was drug- free and aspirin- free for at least two weeks prior to blood collection. Blood was collected into 10 mL citrated Vacutainer tubes. The blood was centrifuged for 15 minutes at 150 x g at room temperature, and platelet-rich plasma (PRP) was removed. The remaining blood was centrifuged for 15 minutes at 1500 x g at room temperature, and platelet-poor plasma (PPP) was removed. Samples were assayed on a aggregometer (PAP-4 Platelet Aggregation Profiler) , using PPP as the blank (100% transmittance) . 200 μL of PRP was added to each micro test tube, and transmittance was set to 0%. 20 μL of various agonists (ADP, collagen, arachidonate, epinephrine, thrombin) were added to each tube, and the aggregation profiles were plotted (% transmittance versus time) . The results are expressed as % inhibition of agonist-induced platelet aggregation. For the IC 50 evaluation, the test compounds were added at various concentrations prior to the activation of the platelets. Ester prodrugs were preincubated (10 ~3 M F.C.) with 100 IU/mL Porcine liver esterase (Sigma Chemical Co. , St. Louis, MO, #E-3128) for 2 hours at 37 °C. Aliquots are then diluted in 0.1 M Tris, pH 7.4, to the desired concentrations. Aliquots of 20 μl of the esterase pretreated prodrugs are added to 200 μl of human ^ platelet rich plasma. Samples were placed in platelet profiler (aggregometer) for 8 minutes at 37 °C, followed by the addition of 100 μM Adenosine Diphosphate, (Sigma Chemical Co., St. Louis, MO, #A-6521) , to induce platelet aggregation. Platelet aggregation was allowed to proceed for 5 minutes. Percent inhibition is calculated using percent aggregation in the presence of the test compound divided by percent aggregation of control, times 100. This value is subtracted from 100, yielding percent inhibition. Calculation of IC 50 is performed on a Texas Instruments TI59 with an IC 50 program. Purified GPIlb/IIIa-Fιbrιnoσf?π Binding ELISA The following reagents are used m the GPIIb/IIIa-fibrinogen binding ELISA: purified GPIIb/IIIa (148.8 μg/mL) ; biotinylated fibrinogen (~ 1 mg/mL or 3000 nM) ; anti-biotm alkaline phosphatase conjugate (Sigma no. A7418) ; flat-bottom, high binding, 96-well plates (Costar Cat. no. 3590); phosphatase substrate (Sigma 104) (40 mg capsules); bovine serum albumin (BSA) (Sigma no. A3294); Alkaline Phosphatase buffer - 0.1 M glycme-HCl, 1 mM MgCl 2 *6H 2 0, 1 mM ZnCl 2 , pH 10.4; Binding buffer - 20 mM Tπs-HCl, 150 mM NaCl, 1 mM CaCl 2 .2H 2 0, 0.02% NaN 3 , pH 7.0; Buffer A - 50 mM Tris-HCl, 100 mM NaCl, 2 mM CaCl 2 .2H 2 0, 0.02% NaN 3 , pH 7.4; Buffer A + 3.5% BSA (Blocking buffer); Buffer A + 0.1% BSA (Dilution buffer); 2N NaOH. The following method steps are used in the GPIIb/IIIa-fibrinogen binding ELISA: Coat plates with GPIIb/IIIa Binding buffer (125 ng/100 μL/well) overnight at 4 °C (Leave first column uncoated for non-specific binding) . Cover and freeze plates at -70 °C until used. Thaw plate 1 hour at room temperature or overnight at 4 °C. Discard coating solution and wash once with 200 μL Binding buffer per well. Block plate 2 hours at room temperature on shaker with 200 μL Buffer A + 3.5% BSA (Blocking buffer) per well. Discard Blocking buffer and wash once with 200 μL Buffer A + 0.1% BSA (Dilution buffer) per well. Pipet 11 μL of test compound (10X the concentration to be tested in Dilution buffer) into duplicate wells. Pipet 11 μL Dilution buffer into non-specific and total binding wells. Add 100 μL Biotmylated fibrinogen (1/133 in Dilution buffer, final concentration = 20 nM) to each well. Incubate plates for 3 hours at room temperature on a plate shaker. Discard assay solution and wash twice with 300 μL Binding buffer per well. Add 100 mL Anti-biotm alkaline phosphatase conjugate (1/1500 in Dilution buffer) to each well. Incubate plates for 1 hour at room temperature on plate shaker. Discard conjugate and wash twice with 300 51 Binding buffer per well. Add 100 μL Phosphatase substrate (1.5 mg/mL m Alkaline phosphatase buffer) to each well. Incubate plate at room temperature on shaker until color develops. Stop color development by adding 25 μL 2N NaOH per well. Read plate at 405 nm. Blank against non-specific binding (NSB) well. % Inhibition is calculated as 100 - (Test Compound Abs/Total Abs)xl00. Plat l t-Fibrinogen Binding Assay : Binding of 125 I- fibrinogen to platelets was performed as described by Bennett et al. (1983) Proc. Natl. Acad. Sci. USA 80: 2417-2422, with some modifications as described below. Human PRP (h-PRP) was applied to a Sepharose column for the purification of platelet fractions. Aliquots of platelets (5 X 10 8 cells) along with 1 M calcium U chloride were added to removable 96 well plates prior to the activation of the human gel purified platelets (h-GPP) . Activation of the human gel purified platelets was achieved using ADP, collagen, arachidonate, epmephr e, and/or thrombin in the presence of the ligand, 125 I-fιbnnogen. The 125 I-fιbnnogen oound to the activated platelets was separated from the free form by centrifugation and then counted on a gamma counter. For an IC50 evaluation, the test compounds were added at various concentrations prior to the activation of the platelets. The compounds of Formula I of the present invention may also possess thrombolytic efficacy, that is, they are capable of lysing (breaking up) already formed platelet-rich fibrin blood clots, and thus are useful in treating a thrombus formation, as evidenced by their activity m the tests described below. Preferred compounds of the present invention for use in thrombolysis include those compounds having an IC5 0 value (that is, the molar concentration of the compound capable of achieving 50% clot lysis) of less than about 1 μM, more preferably an IC 50 value of less than about 0.1 μM. Thrombolytic Assav: Venous blood was obtained from the arm of a healthy human donor who was drug-free and aspirin free for at least two weeks prior to blood collection, and placed into 10 ml citrated Vacutainer tubes. The blood was centrifuged for 15 minutes at 1500 x g at room temperature, and platelet rich plasma (PRP) was removed. To the PRP was then added 1 x 10 "3 M of the agonist ADP, epmephrme, collagen, arachidonate, serotonin or thrombin, or a mixture thereof, and the PRP incubated for 30 minutes. The PRP was centrifuged for 12 minutes at 2500 x g at room temperature. The supernatant was then poured off, and the platelets remaining in the test tube were resuspended in platelet poor plasma (PPP), which served as a plasminogen source. έT- The suspension was then assayed on a Coulter Counter (Coulter Electronics, Inc., Hialeah, FL) , to determine the platelet count at the zero time point. After obtaining the zero time point, test compounds were added at various concentrations. Test samples were taken at various time points and the platelets were counted using the Coulter Counter. To determine the percent of lysis, the platelet count at a time point subsequent to the addition of the test compound was subtracted from the platelet count at the zero time point, and the resulting number divided by the platelet count at the zero time point. Multiplying this result by 100 yielded the percentage of clot lysis achieved by the test compound. For the IC 5 0 evaluation, the test compounds were added at various concentrations, and the percentage of lysis caused by the test compounds was calculated. The compounds of Formula I of the present invention are also useful for administration m combination with anti-coagulant agents such as warfarin or heparin, or antiplatelet agents such as aspirin, piroxicam or ticlopidine, or thrombin inhibitors such as boropeptides, hirudin or argatroban, or thrombolytic agents such as tissue plasminogen activator, anistreplase, urokinase or streptokinase, or combinations thereof. The compounds of Formula I of the present invention may also be useful as antagonists of other tegrins such as for example, the a v / 3 or vitronectin receptor, a 4 bι or as i and as such may also have utility n the treatment and diagnosis of osteoporosis, cancer metastasis, diabetic ret opathy, rheumatoid arthritis, inflammation, and autoimmune disorders. The compounds of Formula I of the present invention may be useful for the treatment or prevention of other diseases which involve cell adhesion processes, including, but not limited to, infanimation, bone degradation, rheumatoid arthritis, asthma, allergies, adult respiratory distress έ8 syndrome, graft versus host disease, organ transplantation, septic shock, psoriasis, eczema, contact dermatitis, osteoporosis, osteoarthritis, atherosclerosis, metastasis, wound healing, diabetic retinopathy, inflammatory bowel disease and other autoimmune diseases. Table A below sets forth the antiplatelet activity of representative compounds of the present invention. The indicated compounds were tested for their ability to inhibit platelet aggregation (using platelet rich plasma (PRP) ) . The IC 50 value (the concentration of antagonist which inhibits platelet aggregation by 50% relative to a control lacking the antagonist) is shown. In Table 5 the IC 50 values are expressed as: +++ = IC 5 0 of <10 μM (μM = micromolar) . Table A Fxamnle Number Plat l Platele Aggreg t on Assay Aggregation Assay X.50 (without C.50 (with esterase) esterase) 1 +++ 2 +++ 3 +++ 16 +++ 17 +++ 28 +++ 29 +++ 32 +++ 33 +++ 37 +++ 38 +++ 68 +++ 69 +++ 70 +++ 71 +++ 300 +++ 301 +++ 321 +++ 322 +++ 327 + ++ 328 +++ 335 +4 + 336 +++ 355 +++ 356 +++ Dosage and Formulation The compounds of the present invention can be administered in such oral dosage forms as tablets, capsules (each of which includes sustained release or timed release formulations), pills, powders, granules, elixirs, tinctures, suspensions, syrups, and emulsions. Likewise, they may also be administered in intravenous (bolus or infusion), intraperitoneal, subcutaneous, or intramuscular form, all using dosage forms well known to those of ordinary skill in the pharmaceutical arts. An effective but non-toxic amount of the compound desired can be employed as an anti-aggregation agent. Finally, the compounds of the invention may also be administered mtranasally. The compounds of this invention can be administered by any means that produces contact of the active agent with the agent's site of action, glycoprote Ilb/IIIa (GPIIb/IIIa), in the body of a mammal. They can be administered by any conventional means available for use n conjunction with pharmaceuticals, either as individual therapeutic agents or in a combination of therapeutic agents, such as a second antiplatelet agent such as aspirin or ticlopidine which are agonist- specific. They can be administered alone, but generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice. The dosage regimen for the compounds of the present invention will, of course, vary depending upon known factors, such as the pharmacodynamic characteristics of the particular agent and its mode and route of administration; the species, age, sex, health, medical condition, and weight of the recipient; the nature and extent of the symptoms; the kind of concurrent treatment; the frequency of treatment; the route of administration, the renal and hepatic function of the patient, and the effect desired. An ordinarily skilled physician or veterinarian can readily determine and prescribe the effective amount of the drug required to prevent, counter, or arrest the progress of the condition. By way of general guidance, the daily oral dosage of each active ingredient, when used for the indicated effects, will range between about 0.001 to 1000 mg/kg of body weight, preferably between about 0.01 to 100 mg/kg of body weight per day, and most preferably between about 1.0 to 20 mg/kg/day. Intravenously, the most preferred doses will range from about 1 to about 10 mg/kg/minute during a constant rate infusion. Advantageously, compounds of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three, or four times daily. The compounds for the present invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches wall known to those of ordinary skill in that art. To be administered in the form of a transdermal delivery system, the dosage administration will, of course, be continuous rather than intermittant throughout the dosage regimen. ?l In the methods of the present invention, the compounds herein described in detail can form the active ingredient, and are typically administered in admixture with suitable pharmaceutical diluents, excipients, or carriers (collectively referred to herein as carrier materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices. For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl callulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral drug components can be combined w th any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water, and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents, and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth, or sodium algmate, carboxymethylcellulose, polyethylene glycol, waxes, and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum, and the like. The compounds of the present invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamallar vesicles, and multilamellar vesicles. Liposomes can be ?2 formed from a variety of phospholipids, such as cholesterol, stearylamine, or phosphatidylcholines. Compounds of the present invention may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran copolymer, polyhydroxypropylmethacrylamide-phenol, polyhydroxyethylaspartamidephenol, or polyethyleneoxide- polylysine substituted with palmitoyl residues. Furthermore, the compounds of the present invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example, polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacylates, and crosslinked or amphipathic block copolymers of hydrogels . Dosage forms (pharmaceutical compositions) suitable for administration may contain from about 1 milligram to about 100 milligrams of active ingredient per dosage unit. In these pharmaceutical compositions the active ingredient will ordinarily be present in an amount of about 0.5-95% by weight based on the total weight of the composition. The active ingredient can be administered orally in solid dosage forms, such as capsules, tablets, and powders, or in liquid dosage forms, such as elixirs, syrups, and suspensions. It can also be administered parenterally, in sterile liquid dosage forms. Gelatin capsules may contain the active ingredient and powdered carriers, such as lactose, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets . Both tablets and capsules can be manufactured as sustained release products to provide for continuous release of medication over a period of 71 hours. Compressed tablets can be sugar coated or film coated to mask any unpleasant taste and protect the tablet from the atmosphere, or enteric coated for selective disintegration m the gastrointestinal tract. Liquid dosage forms for oral administration can contain coloring and flavoring to increase patient acceptance. In general, water, a suitable oil, saline, aqueous dextrose (glucose) , and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are suitable carriers for parenteral solutions. Solutions for parenteral administration preferably contain a water soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidizmg agents such as sodium bisulfite, sodium sulfite, or ascorbic acid, either alone or combined, are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addition, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl- or propyl -paraben, and chlorobutanol. Suitable pharmaceutical carriers are described in Remington's Pharmaceutical .ΓIPΠΓPS. Mack Publishing Company, a standard reference text in this field. Representative useful pharmaceutical dosage- forms for administration of the compounds of this invention can be illustrated as follows: Capsules A large number of unit capsules are prepared by filling standard two-piece hard gelatin capsules each with 1-20 milligrams of powdered active ingredient, 150 milligrams of lactose, 50 milligrams of cellulose, and 6 milligrams magnesium stearate. Soft Gelatin Canailles A mixture of active ingredient m a digestable oil such as soybean oil, cottonseed oil or olive oil is prepared and injected by means of a positive ? < ■ displacement pump into gelatin to form soft gelatin capsules containing 1-20 milligrams of the active ingredient. The capsules are washed and dried. Tablets A large number of tablets are prepared by conventional procedures so that the dosage unit was 1-20 milligrams of active ingredient, 0.2 milligrams of colloidal silicon dioxide, 5 milligrams of magnesium stearate, 275 milligrams of microcrystalline cellulose, 11 milligrams of starch and 98.8 milligrams of lactose. Appropriate coatings may be applied to increase palatability or delay absorption. Imectable A parenteral composition suitable for administration by injection is prepared by stirring 1.5% by weight of active ingredient in 10% by volume propylene glycol and water. The solution is made isotonic with sodium chloride and sterilized. Suspension An aqueous suspension is prepared for oral administration so that each 5 mL contain 1-20 mg of finely divided active ingredient, 200 mg of sodium carboxymethyl cellulose, 5 mg of sodium benzoate, 1.0 g of sorbitol solution, U.S. P., and 0.025 mL of vanillin. The compounds of the present invention may be administered m combination with a second therapeutic agent selected from: an an i-coagulant agent such as warfarin or heparin; an anti-platelet agent such as aspirin, piroxicam or ticlopidine; a thrombin inhibitor such as a boropeptide thrombin inhibitor, or hirudin; or a thrombolytic agent such as plasminogen activators, such as tissue plasminogen activator, anistreplase, urokinase or streptokinase. The compound of Formula I and such second therapeutic agent can be administered separately or as a physical combination m a single dosage unit, in any dosage form and by various routes of administration, as described above. The compound of Formula I may be formulated together with the second therapeutic agent in a single dosage unit (that is, combined together in one capsule, tablet, powder, or liquid, etc.). When the compound of Formula I and the second therapeutic agent are not formulated together in a single dosage unit, the compound of Formula I and the second therapeutic agent (anti-coagulant agent, anti-platelet agent, thrombin inhibitor, and/or thrombolytic agent) may be administered essentially at the same time, or in any order ; for example the compound of Formula I may be administered first, followed by administration of the second agent (anti-coagulant agent, anti-platelet agent, thrombin inhibitor, and/or thrombolytic agent). When not administered at the same time, preferably the administration of the compound of Formula I and the second therapeutic agent occurs less than about one hour apart . A preferable route of administration of the compound of Formula I is oral. Although it is preferable that the compound of Formula I and the second therapeutic agent (anti-coagulant agent, anti-platelet agent, thrombin inhibitor, and/or thrombolytic agent) are both administered by the same route (that is, for example, both orally) , if desired, they may each be administered by different routes and in different dosage forms (that is, for example, one component of the combination product may be administered orally, and another component may be administered intravenously) . The dosage of the compound of Formula I when administered alone or in combination with a second therapeutic agent may vary depending upon various factors such as the phar acodynamic characteristics of the particular agent and its mode and route of administration, the age, health and weight of the ?έ recipient, the nature and extent of the symptoms, the kind of concurrent treatment, the frequency of treatment, and the effect desired, as described above. Although the proper dosage of the compound of Formula I when administered m combination with the second therapeutic agent will be readily ascertamable by a medical practitioner skilled in the art, once armed with the present disclosure, by way of general guidance, where the compounds of this invention are combined with anti-coagulant agents, for example, a daily dosage may be about 0.1 to 100 milligrams of the compound of Formula I and about 1 to 7.5 milligrams of the anticoagulant, per kilogram of patient body weight. For a tablet dosage form, the novel compounds of this invention generally may be present in an amount of about 1 to 10 milligrams per dosage unit, and the anticoagulant in an amount of about 1 to 5 milligrams per dosage unit. Where the compounds of Formula I are administered in combination with a second anti-platelet agent, by way of general guidance, typically a daily dosage may be about 0.01 to 25 milligrams of the compound of Formula I and about 50 to 150 milligrams of the additional antiplatelet agent, preferably about 0.1 to 1 milligrams of the compound of Formula I and about 1 to 3 milligrams of antiplatelet agents, per kilogram of patient body weight . Further, by way of general guidance, where the compounds of Formula I are adminstered in combination with thrombolytic agent, typically a daily dosage may be about 0.1 to 1 milligrams of the compound of Formula I, per kilogram of patient body weight and, in the case of the thrombolytic agents, the usual dosage of the thrombolyic agent when administered alone may be reduced by about 70-80% when administered with a compound of Formula I . 7? Where two or more of the foregoing second therapeutic agents are administered with the compound of Formula I, generally the amount of each component in a typical daily dosage and typical dosage form may be reduced relative to the usual dosage of the agent when administered alone, in view of the additive or synergistic effect of the therapeutic agents when administered in combination. Particularly when provided as a single dosage unit, the potential exists for a chemical interaction between the combined active ingredients. For this reason, when the compound of Formula I and a second therapeutic agent are combined in a single dosage unit they are formulated such that although the active ingredients are combined in a single dosage unit, the physical contact between the active ingredients is minimized (that is, reduced) . For example, one active ingredient may be enteric coated. By enteric coating one of the active ingredients, it is possible not only to minimize the contact between the combined active ingredients, but also, it is possible to control the release of one of these components in the gastrointestinal tract such that one of these components is not released in the stomach but rather is released in the intestines. One of the active ingredients may also be coated with a sustained- release material which effects a sustained-release throughout the gastrointestinal tract and also serves to minimize physical contact between the combined active ingredients. Furthermore, the sustained-released component can be additionally enteric coated such that the release of this component occurs only m the intestine. Still another approach would involve the formulation of a combination product in which the one component is coated with a sustained and/or enteric release polymer, and the other component is also coated with a polymer such as a lowviscosity grade of hydroxypropyl methylcellulose (HPMC) or other ?8 appropriate materials as known m the art, in order to further separate the active components. The polymer coating serves to form an additional barrier to interaction with the other component. These as well as other ways of minimizing contact between the components of combination products of the present invention, whether administered m a single dosage form or administered in separate forms but at the same time by the same manner, will be readily apparent to those skilled in the art, once armed with the present disclosure. The present invention also includes pharmaceutical kits useful, for example, in the inhibition of platelet aggregation, the treatment of blood clots, and/or the treatment of thromboembolic disorders, which comprise one or more containers containing a pharmaceutical composition comprising a therapeutically effective amount of a compound of Formula I. Such kits may further include, if desired, one or more of various conventional pharmaceutical kit components, such as, for example, containers with one or more pharmaceutically acceptable carriers, additional containers, etc., as will be readily apparent to those skilled in the art. Instructions, either as inserts or as labels, indicating quantities of the components to be administered, guidelines for administration, and/or guidelines for mixing the components, may also be mcluded in the kit. In the present disclosure it should be understood that the specified materials and conditions are important in practicing the invention but that unspecified materials and conditions are not excluded so long as they do not prevent the benefits of the invention from being realized. ϋ

Claims: Claims What is claimed is: 1. A compound of the formula (i) or their pharmaceutically acceptable salts thereof, wherein : R 1 is R 2 HN-, R 2 HN(R 2 N=)C-, R 2 HN (CH 2 ) q Z- , RHN(R 2 N=)C(CH 2 ) q Z-, R 2 HN(RN= ) CN(R ) - , R 2 HNC(0)-, R 2 (R 5 0)N(R 2 N=)C-, or R 2 HN(R b ON=) C- ; q is 1-3; Z is a bond (i.e. is absent), 0, S, or S(=0), S(=0) ; R 2 is H, aryl(Cι-Cιo alkoxy) carbonyl, or Cχ-Cιo alkoxycarbonyl, C 1 -C 4 alkyl, C 3 -C 6 alkenyl; R 3 is H, Cι-C 6 alkyl, C 2 -C 5 alkenyl, C 2 -C 6 alkynyl, C 3 -C 7 cycloalkyl, - (phenyl) - substituted with 0-2 R 6 , or - (pyridyl) - substituted with 0-2R 6 ; R 5 is H or C 1 -C 10 alkyl substituted with 0-1 R b ; R 4b is Cι-C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 7 cycloalkyl, C 7 -C 14 bicycloalkyl, hydroxy, Ci-Cβ alkoxy, C 1 -C 6 alkylthio, Cι-C 6 alkylsulfinyl, Ci~C 6 alkylsulfonyl, nitro, Ci-C δ alkylcarbonyl, C 6 -Cι 0 aryl, -N(R 12 )R 13 ; halo, CF 3 , CN, Ci-Cβ alkoxycarbonyl, carboxy, piperidinyl, morpholinyl or pyridinyl; Ar is a single bond; -(phenyl)- substituted with 0-2 R 6a , -(piperidinyl)- substituted with 0-2 R 6α , or -(pyridyl)- substituted with 0-2 R 6a ; R 6a is C 1 -C 4 alkyl, C 1 -C 4 alkoxy, halo, CF 3 , N0 , or NR 12 R 13 ; X is -C(O)- or a single bond; So Y is hydroxy, Ci to Cio alkyloxy, C 3 to Cn cycloalkyloxy, & to Cio aryloxy, C 7 to Cn aralkyloxy, C3 to Cio alkylcarbonyloxyalkyloxy, C 3 to Cio alkoxycarbonyloxyalkyloxy, C to Cio alkoxycarbonylalkyloxy, C 5 to Cio cycloalkylcarbonyloxyalkyloxy, C 5 to Cio cycloalkoxycarbonyloxyalkyloxy, C 5 to Cio cycloalkoxycarbonylalkyloxy, C 7 to Cn aryloxycarbonylalkyloxy, Cβ to C 2 aryloxycarbonyloxyalkyloxy, Cs to C arylcarbonyloxyalkyloxy, C 5 to Cio alkoxyalkylcarbonyloxyalkyloxy, C 5 to Cio (5-alkyl- 1, 3-dioxa-cyclopenten-2-one-yl)methyloxy, Cio to C 14 ( 5-aryl-l, 3-dioxa-cyclopenten-2-one-yl)methyloxy, or (R 2 )HN-(Cι-Cιo alkoxy)-; m is 0-2 ; n is 0-4; R 9 and R 10 are each independently H, Ci-Cβ alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C7 cycloalkyl, - (phenyl) - substituted with 0-2 R 5a , or - (pyridyl) - substituted with 0-2R 6a ; R 11 is -C(=0) -0-R 14a , -C(=0)-R 14b , -C(=0)N(R 14b ) 2 , -C(=0)NHS0 2 R 14a , -C(=0)NHC(=0)R 14b , -C(=0)NHC(=0)OR 1 , -C(=0)NHS0 2 NHR 14b , -C(=S)-NH-R 1 b , -NH-C(=0)-O-R 1 a , -NH-C(=0)R 14b , -NH-C(=0)-NH-R 14b , -S0 2 -0-R 1 , -S0 2 -R 1 a , -S0 2 -N(R l4b ) 2 , -S0 2 -NHC(=0)OR 14b , 91 - P ( = S ) (OR 14a ) 2 , -P ( =0) (OR 14a ) 2 , - P ( =S ) ( R 14 a ) 2 , R 12 and R 13 are each independently H, C -Cio alkyl, Ci-Cio alkoxycarbonyl, Ci-Cio alkylcarbonyl, C -Cio alkylsulfonyl, heteroaryl (C- 1 -C 4 alkyl) sulfonyl, aryl (Ci-Cio alkyl) sulfonyl, arylsulfonyl, aryl, heteroarylcarbonyl, heteroarylsulfonyl , or heteroarylalkylcarbonyl, wherein said aryls and heteroaryls are optionally substituted with 0-3 substituents selected from the group consisting of C 1 -C 4 alkyl, C 1 -C 4 alkoxy, halo, CF 3 , and NO ? ; Ci-Cβ alkyl substituted with 0-2R l , C 2 -Cβ alkenyl substituted with 0-2R 15 , C 2 -Cs alkynyl substituted with 0-2R 15 , C 3 -C 8 cycloalkyl substituted with 0-2R l , aryl substituted with 0-4R 15 , aryl (Ci-Cβ alkyl) substituted with 0-4 R 15 , a 5-10 membered heterocyclic ring system having 1-3 heteroatoms selected independently from 0,S, and N, said heterocyclic ring being substituted with 0-4 R 15 , or C1-C6 alkyl substituted with a 5-10 membered heterocyclic ring system having 1-3 heteroatoms selected independently from 0,S, and N, said heterocyclic ring being substituted with 0-4R15; R 14b 1S R 14a or H . R 15 is H, halogen, CF 3 , CN, N0 2 , NR 12 R 13 , Cι-C 8 alkyl, C 2 - Cς, alkenyl, C3-C 11 cycloalkyl, C 4 -C 11 cycloaikylakyl, aryl, aryl(Cι-C 6 alkyl)-, Ci-Cβ alkoxy, or C 1 -C 4 alkoxycarbonyl; £2 provided that m and n are chosen such that the number of atoms connecting R 1 and Y is in the range of 10-18. 2. A compound of the formula (I) or their pharmaceutically acceptable salts, wherein: R 2 is H, Ci-Cio alkoxycarbonyl, or C 1 -C 4 alkyl; R 3 is H, C1-C6 alkyl, or - (phenyl) - substituted with 0-2R 6a ; R 5 is H or C 1 -C 4 alkyl Ar is -(phenyl)- substituted with 0-2 R 6a ; R 6a is C 1 -C 4 alkyl, C1-C 4 alkoxy, halo, CF 3 , N0 2 , or NR 12 R 13 ; X is -C(O)- or a single bond; Y is hydroxy; Ci to Cio alkoxy; methylcarbonyloxymethoxy- ; ethylcarbonyloxymethoxy- ; t-butylcarbonyloxymethoxy- ; cyclohexylcarbonyloxymethoxy- ; 1- (methylcarbonyloxy) ethoxy- ; 1- (ethylcarbonyloxy) ethoxy-; 1- (t-butylcarbonyloxy) ethoxy-; 1- (cyclohexylcarbonyloxy) ethoxy- ; i-propyloxycarbonyloxymethoxy- ; t-butyloxycarbonyloxymethoxy- ; 1- (i-propyloxycarbonyloxy) ethoxy- ; 1- (cyclohexyloxycarbonyloxy) ethoxy-; 91 1- ( t-butyloxycarbonyloxy) ethoxy- ; (5-methyl-l, 3-dioxacyclopenten-2-on-4-yl)methoxy- ; (5- (t-butyl) -1, 3-dioxacyclopenten-2-on-4- yl ) methoxy- ; ( l,3-dioxa-5-phenyl-cyclopenten-2-on-4-yl)methoxy-; 1- (2- ( 2-methoxypropy1 ) carbonyloxy) ethoxy- ; m is 1 or 2; n is 1 or 2; R 11 is -C(=0)-0-R 14 , -C(=0)-R 14b , -C(=0)N(R 1 b ) 2 , -C(=0)NHS0 2 R 14a , -C(=0)NHC(=0)R 14b , -C(=0)NHC(=0)OR 14 , -C(=0)NHS0 2 NHR 14b , -C(=S)-NH-R 14b , -NH-C(=0)-0-R 14a , -NH-C(=0)R 1 b , -NH-C(=0)-NH-R 14b , -S0 2 -0-R 1 a , -S0 2 -R 14a , -S0 2 -N(R 1 b ) 2 , -S0 2 -NHC(=0)OR 14b , -P(=S) (OR 1 a ) 2 , -P(=0) (OR 1 a ) 2 , -P ( =S ) ( R 14 ) 2 - R 12 is H, Ci-C ό alkyl, C 1 -C 4 alkoxycarbonyl, Cι-C 6 alkylcarbonyl, C -Cβ alkylsulfonyl, aryl (C 1 -C 4 alkyl) sulfonyl, heteroaryl (C 1 -C 4 alkyl) sulfonyl, arylsulfonyl, U heteroarylsulfonyl, aryl, pyridylcarbonyl or pyridylmethylcarbonyl, wherein said aryls and heteroaryls are optionally substituted with 0-3 substituents selected from the group consisting of: C 1 -C4 alkyl, C1-C 4 alkoxy, halo, CF 3 , and N0 ; and C 1 -C8 alkyl substituted with 0-2R 15 , C -Ce alkenyl substituted with 0-2R 15 , C -Cs alkynyl substituted with 0-2R 15 , C3-C8 cycloalkyl substituted with 0-2R 15 , aryl substituted with 0-4R 15 , aryl (Cι-C 6 alkyl) substituted with 0-4R 15 a 5-10 membered heterocyclic ring system having 1-3 heteroatoms selected independently from 0,S, and N, said heterocyclic ring being substituted with 0-4 R 15 , or C1-C6 alkyl substituted with a 5-10 membered heterocyclic ring system having 1-3 heteroatoms selected independently from 0,S, and N, said heterocyclic ring being substituted with 0-4R15; R 14b 1S R 14a or H . and R 15 is H, halogen, CF 3 , CN, N0 2 , NR 12 R 13 , Cι-C 8 alkyl, C 2 - C 6 alkenyl, C 3 -C 11 cycloalkyl, C 4 -C 11 cycloalkylakyl, aryl, aryl(Cι-C 6 alkyl)-, Ci-Cβ alkoxy, or C 1 -C4 alkoxycarbonyl. 3. A compound of claim 2 selected from the group consisting of: Cis-3- [2- [2-methyl-3- (4-amidinophenyl ) - isoxazolidin-5-yl ] -acetyl ] amino-N- (3- methylphenyl sulf onyl) -L-alanine methyl ester monotrifluoroacetic acid Trans- 3- [2- [2-methyl-3- (4-amidmophenyl) - 25 ιsoxazolιdm-5-yl] acetyl] ammo-N- (3- methylphenylsulfonyl) -L-alanme methyl ester monotrifluoroacetic acid Cis-3- [2- [2-benzyl-3- (4-amιdmophenyl ) - ιsoxazolιdιn-5-yl] acetyl] -N- (3-methylphenylsulfonyl) -L- alan e methyl ester monotrifluoroacetic acid Cis-3- [2- [2-isopropyl-3- (4-amιdmophenyl) - ιsoxazolιdm-5-yl] acetyl] amino-N- (3- ethylphenylsulfonyl) -L-alanme methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amιdmophenyl ) - ιsoxazolιdm-5-yl] acetyl] ammo-N- (2- methylphenylsulfonyl) -L-alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amιdmophenyl ) - isoxazolιdιn-5-yl] acetyl] ammo-N- (3 , 5-dιmethyloxazol-4- ylsulfonyl) -L-alanme methyl ester monotrifluoroacetic Cis-3- [2- [2-methyl-3- (4-amιdmophenyl) - ιsoxazolιdm-5-yl] acetyl] ammo-N-n-butyloxycarbonyl-L- alanine methyl ester monotrifluoroacetic acid Cis-3- [2- [2-phenyl-3- (4-amιdmophenyl ) - ιsoxazolιdm-5-yl] acetyl] ammo-N- (3- methylphenylsulfonyl) -L-alanme methyl ester monotrifluoroacetic acid Cis-3- [2- [2-methyl-3- (4-amιdmophenyl) - isoxazolιdm-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-benzyl-3- (4-amιdmophenyl ) - %έ isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-isopropyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-methyl-3- (4-amidinophenyl ) - isoxazolidin-5-yl] acetyl] amino-N- (2- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-methyl-3- (4-amidinophenyl ) - isoxazolidin-5-yl] acetyl] amino-N- (3 , 5-dimethyloxazol-4- ylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [2- [2-methyl-3- (4-amidinophenyl ) - isoxazolidin-5-yl] acetyl] amino-N-n-butyloxycarbonyl-L- alanine monohydrogenchloride Cis-3- [2- [2-phenyl-3- (4-amidinophenyl) - isoxazolidin-5-yl] acetyl] amino-N- (3- methylphenylsulfonyl) -L-alanine monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] etrahydro-3- methyl-2-oxo-2H-l, 3 -oxazin-6-yl] acetyl] amino] -N- [ (3- methylphenyl ) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl) phenyl] tetrahvdro-3- benzyl-2-oxo-2H-l, 3-oxazin-6-yl]acetyl]amino] -N- [ (3- methylphenyl ) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl ) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazin-6-yl] acetyl] amino] -N- [ (2- ethylphenyl) sulfonyl] -L-alanine methyl ester monohydrogenchloride Cιs-3- [ [ [4- [4- (am oimmomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l , 3-oxazm-6-yl] acetyl] ammo] -N- [(3,5- dimethylisoxazol-4-yl) sulfonyl] -L-alanme methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (am oimmomethyl )phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazιn-6-yl] acetyl] ammo] -N- (n- butyloxycarbonyl) -L-alanine methyl ester monohydrogenchloride Cis-3- [ [ [4- [4- (am oimmomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl] acetyl] ammo] -N- [ (3- methylphenyl ) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (ammoimmomethyl ) phenyl] tetrahydro-3- benzyl-2-oxo-2H-l, 3-oxazιn-6-yl] acetyl] amino] -N- [ (3- ethylphenyl ) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (aminoiminomethyl ) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl] acetyl] ammo] -N- [ (2- methylphenyl ) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (am oimmomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl] acetyl] ammo] -N- [ (3,5- dιmethylιsoxazol-4-yl) sulfonyl] -L-alanme monohydrogenchloride Cis-3- [ [ [4- [4- (ammoimmomethyl) phenyl] tetrahydro-3- methyl-2-oxo-2H-l, 3-oxazm-6-yl] acetyl] amino] -N- (n- butyloxycarbonyl ) -L-alanine monohydrogenchloride 4. A pharmaceutical composition comprising a pharmaceutical carrier and a therapeutically effective amount of a compound of Claim 1 or a pharmaceutically acceptable salt from thereof. $2 5. A pharmaceutical composition comprising a pharmaceutical carrier and a therapeutically effective amount of a compound of Claim 2 or a pharmaceutically acceptable salt form thereof. 6. A pharmaceutical composition comprising a pharmaceutical carrier and a therapeutically effective amount of a compound of Claim 3 or a pharmaceutically acceptable salt form thereof. 7. A method in inhibiting the aggregation of blood platelets which comprises administering to a host in need of such inhibition a therapeutically effective amount of a compound of Claim 1. 8. A method of inhibiting the aggregation of blood platelets which comprises administering to a host in need of such inhibition a therapeutically effective amount of a compound of Claim 2. 9. A method of inhibiting the aggregation of blood platelets which comprises administering to a host in need of such inhibition a therapeutically effective amount of a compound of Claim 3. 10. A method of treating thromboembolic disorders selected from thrombus or embolus formation, harmful platelet aggrgation, reocclusion following thrombolysis, reperfusion injury, restenosis, atherosclerosis, stroke, myocardial infarction, and unstable angina, which comprises administering to a host in need of such treatment a therapeutically effective amount of a compound of Claim 1. 11. A method of treating thromboembolic disorders selected from thrombus or embolus formation, harmful S°) platelet aggregation, reocclusion following thrombolysis, reperfusion injury, restenosis, atherosclerosis, stroke, myocardial infarction, and unstable angina, which comprises administering to a host in need of such treatment a threapeutically effective amount of a compound of Claim 2. 12. A method of treating thromboembolic disorders selected from thrombus or embolus formation, harmful platelet aggregaion, reocclusion following thrombolysis, reperfusion injury, restenosis, atherosclerosis, stroke myocardial infarction, and unstable angina, which comprises administering to a host in need of such treatment a therapeutically effective amount of a compound of Claim 3. < 30

Inventors: CONFALONE PASQUALE NICHOLAS, JIN FUQIANG, CONFALONE, PASQUALE, NICHOLAS, Jin, Fuqiang
Applicants: DU PONT MERCK PHARMA, THE DU PONT MERCK PHARMACEUTICAL COMPANY
Application year: 1997
Main classification: C07D261
IPC codes: A61K31, A61P7, A61P9, C07D261, C07D265, C07D413