Abstract:
The present invention provides novel compounds represented by the general  
                         
 
     wherein m, n, X, Y, Z, R, R 1  and R 2  are as defined in the specification or a pharmaceutically acceptable salt thereof. The novel compounds are PGF 2α  antagonists, useful in pharmaceutical compositions for treating PGF 2α -mediated disease responses such as inflammatory reactions relating to rheumatoid arthritis and psoriasis, reproductive disorders, bronchoconstrictive disorders (asthma), excessive bone breakdown (osteoporosis), peptic ulcers, heart disease, platelet aggregation and thrombosis.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This patent application is a continuation in part of U.S. Patent application Ser. No. 09/840,675, entitled INTERPHENYLENE 7-OXABICYCLIC [2.2.1]HEPTANE OXAZOLES AS PROSTAGLANDIN F 2α  ANTAGONISTS filed on Apr. 23, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention provides novel Interheteroaryl 7-Oxabicyclo [2.2.1] heptane oxazoles useful as Prostaglandin F 2α  (FP receptor) antagonists. The present invention also provides a method of synthesizing such novel compounds.  
           [0004]    2. Description of Related Art  
           [0005]    Prostaglandin F 2α  antagonists are reported in U.S. Pat. Nos. 4,632,928; 5,747,660; and 5,955,575. The PGF 2α  antagonists of U.S. Pat. No. 4,632,928 are pyrazole derivatives having an ergoline skeleton. The PGF 2α  antagonist of U.S. Pat. No. 5,747,660 is a prostaglandin F 2α  receptor regulatory protein (FPRP) which is able to inhibit the binding of PGF 2α  to its receptor. The inventors of this patent state that the prostaglandin F 2α  antagonist of their invention is believed to be the first selective prostaglandin F 2α  antagonist discovered. U.S. Pat. No. 5,955,575 describes peptide sequences derived from the prostaglandin receptor F 2α  and the G-protein, Gαq, as selective inhibitors of signal transduction involved in the stimulation of the prostaglandin receptor F 2α .  
           [0006]    Interphenylene 7-Oxabicyclo [2.2.1] heptane oxazoles, useful as Thromboxane A 2  receptor antagonists are reported in U.S. Pat. No. 5,100,889 and 5,153,327, European Patent Application 0 391 652 and J. Med. Chem. 1993, 36, 1401-1417.  
           [0007]    Thromboxane A 2  receptor antagonists, e.g. 7-oxabicycloheptyl substituted heterocyclic amide prostaglandin analogs, alone, or in combination with anti-inflammatory agents are useful in treating ulcerative gastrointestinal conditions and dysmenorrhea as disclosed in European Patent Application 0 448 274 and U.S. Pat. No. 5,605,917.  
         BRIEF SUMMARY OF THE INVENTION  
         [0008]    The invention relates to novel Interheteroaryl 7-Oxabicyclo [2.2.1] heptane oxazoles useful as PGF 2α  antagonists, the synthesis thereof, and their use in treating diseases and conditions, where PGF 2α  is involved.  
           [0009]    The novel compounds of the present invention are represented by the general formula I.  
                         
 
           [0010]    wherein  
           [0011]    m is an integer of from 1 to 3, preferably 1 or 2;  
           [0012]    n is 0 or an integer of from 1 to 4, preferably from 2 to 4;  
           [0013]    R is selected from the group consisting of CO 2 H, CO 2 R 6 , CH 2 OH, CH 2 OR 6   
                         
 
           [0014]    R 1  and R 2  are independently selected from the group consisting of H, R 6 , C 1 -C 6  alkenyl, C 1 -C 6  alkynyl, C 3 -C 7  cycloalkyl, C 4 -C 12  alkylcycloalkyl, C 6 -C 10  aryl, C 7 -C 12  alkylaryl radicals and heteroatom-substituted derivatives thereof, wherein one or more of the hydrogen or carbon atoms in said radicals is replaced with a halogen, nitrogen or sulfur-containing radical, e.g. F, Cl, Br, I, NO 2 , N(R 7 ) 2 , CON(R 7 ) 2 , SR 7  and CN, wherein R 7  is selected from the group consisting of H and C 1 -C 6  alkyl;  
           [0015]    R 3  and R 4  are independently selected from the group consisting of H and R 6 ; and  
           [0016]    X is selected from the group consisting of H, R 6 , hydroxy, halogen, COOR 6 , NO 2 , N(R 6 ) 2 , CON(R 6 ) 2 , SR 6 , CN and OR 6  wherein R 6  is C 1 -C 6  alkyl; Y is O or S; Z is N or CH and pharmaceutically acceptable salts thereof.  
           [0017]    These compounds are especially useful for treating a number of PGF 2α —mediated disease responses. For instance, prostaglandins play an important role in inflammatory reactions relating to rheumatoid arthritis and psoriasis, reproductive disorders, bronchoconstrictive disorders (asthma), excessive bone breakdown (osteoporosis), peptic ulcers, heart disease, platelet aggregation and thrombosis. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 describes the synthesis of a silylether intermediate, prepared according to Examples 1 through 8, below, and useful in the preparation of compounds related to the novel compounds of the invention.  
         [0019]    [0019]FIG. 2 describes the synthesis of an acetate intermediate, prepared according to Examples 9 through 14, below, and useful in the preparation of compounds related to the novel compounds of the invention.  
         [0020]    [0020]FIG. 3 describes the synthesis of a compound related to the compounds of the present invention, prepared according to Examples 16 through 21, below.  
         [0021]    [0021]FIG. 4 describes the synthesis of an alcohol intermediate prepared according to Example 23, below, and useful in the preparation of the compounds of the present invention.  
         [0022]    [0022]FIG. 5 describes a dose response curve for the antagonist of U.S. Pat. No. 5,100,889 and 5,153,327.  
         [0023]    [0023]FIG. 6 describes a dose response curve for the 1-methyl ester of the antagonist of U.S. Patent Nos. 5,100,889 and 5,153,327.  
         [0024]    [0024]FIG. 7 describes a dose response curve for the compound of Example 24, below. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]    Preferably, the novel interheteroaryl-7-oxabicyclo [2.2.1] heptane oxazole compound are represented by the general formula II  
                         
 
         [0026]    Preferably, R is selected from the group consisting of CO 2 H, CO 2 R 6 , CH 2 OH, CH 2 OR 6  and CONR 3 R 4 .  
         [0027]    More preferably R is selected from the group consisting of CO 2 H and CO 2 R 6 , e.g. CO 2 H and CO 2 CH 3 .  
         [0028]    Preferably, R 1  and R 2  are selected from the group consisting of H, R 6 , C 3 -C 7  cycloalkyl and C 4 -C 12  alkylcycloalkyl.  
         [0029]    Preferably X is selected from the group consisting of H and halogen, e.g. fluoro; most preferably X is H.  
         [0030]    Preferably Y is S.  
         [0031]    Preferably Z is CH.  
         [0032]    More preferably, the novel compounds of the present invention are represented by the general formula III.  
                         
 
         [0033]    For the compounds of formula III, Y is preferably S and X is preferably H.  
         [0034]    The following Examples 1-22 describe a method of synthesizing compounds relating to the novel compounds of the invention wherein the numbering of the Examples corresponds to the numbering of the various intermediates and final compounds shown in FIGS. 1 through 3. Examples 23 and 24 describe a method of synthesizing one of the novel compounds of this invention.  
       EXAMPLE 1  
     2-Bromo-4-fluorobenzoic acid  
       [0035]    The named compound is purchased from Marshallton Research Laboratories Inc., P.O. Box 930, King, N.C. 27021.  
       EXAMPLE 2  
     2-Bromo-4-fluorobenzoic acid, methylester  
       [0036]    A solution of 2-bromo-4-fluorobenzoic acid (5 g, 22.8 mmol), DBU (5.21 g, 34.2 mmol), and methyl iodide (6.48 g, 45.7 mmol) in acetone (23 mL) was stirred at room temperature for 2 h. The reaction was concentrated in vacuo and the residue partitioned between EtOAc and 1 M HCl. The organic portion was washed with saturated aqueous NaHCO 3 , brine and then was dried (MgSO 4 ), filtered and evaporated to give the ester of Example 2 (5.18 g) which was used directly in the next step.  
       EXAMPLE 3  
     (2-Bromo-4-fluorophenyl) methanol  
       [0037]    DIBAL-H (56 mL, 56 mmol, 1M/toluene) was added to a solution of the ester of Example 2 (5.18 g, 22.2 mmol) in toluene (50 mL) at −78° C. After 1 h, the reaction was warmed to room temperature and quenched by dropwise addition of 1 M NaOH. The mixture was extracted with EtOAc. The organic portion was washed with brine and then was dried (MgSO 4 ), filtered, and evaporated to give the alcohol of Example 3 (4.55 g) which was used directly in the next step.  
       EXAMPLE 4  
     2-Bromo-4-fluorobenzaldehyde  
       [0038]    A mixture of the alcohol of Example 3 (4.55 g, 22.2 mmol), PDC (10.0 g, 26.6 mmol), MgSO 4  (10.0 g) and crushed 4 Å molecular sieves (10.0 g) in CH 2 Cl 2  (44 mL) was stirred for 12 h. The mixture was diluted with ether and filtered through celite. The solvent was evaporated and the residue purified by flash column chromatography on silica gel (10% EtOAc/hexanes) to give the aldehyde of Example 4 (3.43 g, 16.9 mmol, 74% from 2-bromo-4-fluorobenzoic acid).  
       EXAMPLE 5  
     (E)-3-(2-Bromo-4-fluorophenyl)acrylic acid methyl ester  
       [0039]    A mixture of the aldehyde of Example 4 (4.5 g, 22.2 mmol) and methyl(triphenylphosphoranylidene)acetate (8.91 g, 36.6 mmol) in toluene (22 mL) was stirred for 12 h. The solvent was removed in vacuo and the residue was purified by flash chromatography on silica gel (5% EtOAc/hexanes) to give the ester of Example 5 (5.46 g, 21.1 mmol, 95%).  
       EXAMPLE 6  
     3-(2-Bromo-4-fluorophenyl)propionic acid methyl ester  
       [0040]    A mixture of (Ph 3 P) 3 RhCl (1.49 g, 1.61 mmol) and the ester of Example 5 (4.17 g, 16.1 mmol) in ethanol (30 mL) was evacuated and purged with H 2(g) . The mixture was stirred under 1 atm H 2  pressure for 12 h. The solvent was removed and the residue was purified by flash column chromatography on silica gel (5% EtOAc/hexanes) to give the ester of Example 6 (3.50 g, 13.4 mmol, 80%).  
       EXAMPLE 7  
     3-(2-Bromo-4-fluorophenyl)propan-1-ol  
       [0041]    A −78° C. solution of the ester of Example 6 (3.50 g, 13.4 mmol) in toluene (20 mL) was treated dropwise with DIBAL-H (33.5 mL, 33.5 mmol, 1 M/toluene). After 1 h, the reaction was warmed to room temperature and then was quenched with dropwise addition of 1 M H 2 SO 4 . The warm mixture was poured onto ice and extracted with EtOAc. The organic portion was washed with saturated NaHCO 3  solution and brine and then was dried (MgSO 4 ), filtered, and evaporated. Purification by flash column chromatography on silica gel (25% EtOAc/hexanes) gave the alcohol of Example 7 (3.09 g, 13.3 mmol, 99%).  
       EXAMPLE 8  
     [3-(2-Bromo-4-fluoro-phenyl)-propoxyl]-dimethyl-(1,1,2-trimethyl-propyl)-silane  
       [0042]    A solution of the alcohol of Example 7, (2.1 g, 9.0 mmol), dimethylthexylsilyl chloride (2.8 mL, 14.2 mmol, Aldrich), Et 3 N (1.36 mL, 9.76 mmol, Aldrich) and 4-(dimethylamino)pyridine (48 mg, 0.39 mmol, Aldrich) in CH 2 Cl 2  (16 mL, Aldrich) was stirred for 18 h. The solution was poured into saturated aqueous NaHCO 3  solution (25 mL) and the mixture extracted with CH 2 Cl 2  (2×25 mL). The combined CH 2 Cl 2  solution was dried (MgSO 4 ), filtered, evaporated and purified by flash column chromatography on silica gel (2% EtOAc/hexanes→30%→40%) to give the silane of Example 8 (2.792 g, 7.4 mmol, 83%).  
       EXAMPLE 9  
       [0043]    A mixture of Mg turnings (173 mg, 7.1 mmol, Aldrich), iodine (2 crystals), and 1,2-dibromoethane (20 μL) in dry THF (2.6 mL, Aldrich) was heated in a 64° C. oil bath with magnetic stirring until the iodine color disappeared (ca. 15 min.). The resulting mixture was allowed to cool to room temperature and a solution of the bromide of Example 8 (1.882 g, 5.0 mmol) in 1.5 mL THF was added dropwise by cannula, rinsing with 1 mL THF. The mixture was heated in the 64° C. oil bath for 3 h, allowed to cool to room temperature and used directly in the next step.  
       EXAMPLE 10  
     3aR-(3aα,4α,7α,7aα)]-1-Hydroxyhexahydro-4,7-epoxyisobenzofuran  
       [0044]    The named compound is prepared according to Das, J.; Haslanger, M. F.; Gougougoutas, J. Z.; Malley, M. F. Synthesis of Optically Active 7-Oxabicyclo [2.2.1]heptanes and Assignment of Absolute Configuration.  Synthesis  1987, 1100-1103 except in the final dibal reduction of the corresponding lactone, the reaction was quenced with methanol and worked up with aqueous NaOH.  
       EXAMPLE 11  
     1-(2-{3-[Dimethyl-(1,1,2-trimethyl-propyl)-silanyloxy]-propyl}-5-fluoro-phenyl)-1-((1R,2S,3R,4R-3-hydroxymethyl-7-oxa-bicyclo[2.2.1]hept-2-yl)-methanol  
       [0045]    An ice-cold solution of lactol 10 (3aR-(3aα, 4α, 7α, 7aα)]-1-Hydroxyhexahydro-4,7-epoxyisobenzofuran (708 mg, 4.53 mmol) in 2.4 mL of dry THF (Aldrich) was treated dropwise with EtMgBr (4.5 mL, 4.5 mmol, 1 M/THF, Aldrich). After 20 min., the Grignard solution from Example 9 above was added by cannula and the solution allowed to warm to room temperature.  
         [0046]    After 16 h, the reaction was quenched by addition of 2.8 mL of saturated NH 4 Cl solution with cooling. The resulting mixture was stirred for 2 h and then CH 2 Cl 2  (10 mL) was added. The solution was decanted from the gum, the gum washed further with CH 2 Cl 2  (3×10 mL), and the combined CH 2 Cl 2  solution was dried (MgSO 4 ), filtered, and evaporated. Purification of the crude product by flash column chromatography on silica gel (40% EtOAc/hexanes) gave the diol of Example 11 (1.386 g, 3.1 mmol, 69%) as an oil.  
       EXAMPLE 12  
     Acetic acid (1R,2R,3S,4R)-3-[1-(2-{3-[dimethyl-(1,1,2-trimethyl-propyl)-silanyloxy]-propyl}-5-fluoro-phenyl)-1-hydroxy-methyl]-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl ester  
       [0047]    The diol of Example 11 (713 mg, 1.62 mmol) was co-evaporated with benzene (2×2 mL). The residue was taken into 1.5 mL of dry pyridine (Aldrich) and was treated with Ac 2 0 (195 μL, 2.07 mmol, Aldrich). The solution was allowed to stir for 17 h and then was evaporated and co-evaporated twice with toluene. Flash column chromatography on silica gel (20% EtOAc/hexanes→30%→40%→50%) gave the monoacetate of Example 12 (564 mg, 1.17 mmol, 72%).  
       EXAMPLE 13  
     Acetic Acid (1R,2R,3R,4R)-3-[1-(2-{3-[dimethyl-(1,1,2-trimethyl-propyl)-silanyloxy]-propyl}-5-fluoro-phenyl)-1-(1-imadazol-1-yl-methanethioyloxy)-methyl]-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl ester  
       [0048]    The acetate of Example 12 (5.64 mg, 1.17 mmol) was co-evaporated with benzene (2×2 mL). The residue was taken into dry dichloroethane (0.8 mL, Aldrich) and thiocarbonyldiimidazole (643 mg, 3.61 mmol, Aldrich) was added. The mixture was heated in a 60° C. oil bath with stirring. After 1 h, there was a considerable amount of starting material and so the solvent level was reduced under a nitrogen stream and the reaction allowed to stir further for another 1 h at which time the reaction was complete (TLC analysis). The mixture was allowed to cool to room temperature and then purified by flash column chromatography on silica gel (30% EtOAc/hexanes→40%) which gave the ester of Example 13 (506 mg, 0.93 mmol, 79%).  
       EXAMPLE 14  
     Acetic acid (1R,2R,3R,4R)-3-(2-{3-[dimethyl-(1,1,2-trimethyl-propyl)-silanyloxy]-propyl}-5-fluoro-benzyl)-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl ester  
       [0049]    A solution of the ester of Example 13 (506 mg, 0.93 mmol), Bu 3 SnH (1.44 mL, 5.35 mmol, Aldrich), and AIBN (53 mg, 0.32 mmol, Alfa) in toluene (45 mL, Aldrich) was heated in a 110° C. oil bath. After 2 h, the reaction was not complete (TLC analysis) and so another 53 mg of AIBN was added. After 1 h of further heating the reaction was complete. The solution was allowed to cool to room temperature, was evaporated and then purified by flash column chromatography on silica gel (100% hexanes→5% EtOAc/hexanes→10%) which gave the ester of Example 14 (366 mg, 0.78 mmol, 84%).  
       EXAMPLE 15  
     3-[4-Fluoro-2-((1R,2R,3R,4R)-3-hydroxymethyl-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl)-phenyl]-propionic acid methyl ester  
       [0050]    A solution of the ester of Example 14 (577 mg, 1.2 mmol) in acetone (6 mL, B &amp; J brand) was treated dropwise with Jones reagent (0.84 mL, 2.5 M in Cr(VI), 2.1 mmol). After 20 min., the reaction was quenched by addition of isopropyl alcohol (0.5 mL). The mixture was allowed to stir for 15 min. and then was filtered through celite. The filtrate was evaporated and the residue was partitioned between CH 2 Cl 2  (20 mL) and 3:1 H 2 O/brine (20 mL). The aqueous portion was further extracted with CH 2 Cl 2  (2×20 mL) and the combined CH 2 Cl 2  solution was dried (MgSO 4 ), filtered and evaporated to leave the acid as a slightly yellow oil that was used directly in the next step.  
         [0051]    The crude acid was taken into a solution of 1% v/v AcCl/MeOH (3.5 mL). After 20 h, NaHCO 3  (110 mg) was added and the mixture diluted with diethyl ether (20 mL). The mixture was dried (MgSO 4 ), filtered, evaporated, and purified by flash column chromatography on silica gel (60% EtOAc/hexanes→67%→75%) which gave 15 3-[4-Fluoro-2-((1R,2R,3R,4R)-3-hydroxymethyl-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl)-phenyl]-propionic acid methyl ester (339 mg, 1.05 mmol, 88% from the ester of Example 14).  
       EXAMPLE 16  
     (1R,2S,3R,4R)-3-[5-fluoro-2-(2-methoxycarbonyl-ethyl)-benzyl]phenyl)-7-oxa-bicyclo[2.2.1]heptane-2-carboxylic acid  
       [0052]    A solution of the ester of Example 15 (336 mg, 1.04 mmol) in acetone (8 mL, B &amp; J brand) was treated dropwise with Jones reagent (0.8 mL, 2.0 mmol, 2.5 M). The orange mixture was allowed to stir for 35 min. and then was quenched by addition of 0.5 mL isopropyl alcohol. After 15 min., the mixture was filtered through celite and evaporated. The residue was partitioned between 10 mL 1 M HCl and 20 mL CH 2 Cl 2 . The aqueous layer was extracted further with CH 2 Cl 2  (2×20 mL) and the combined CH 2 Cl 2  solution dried (MgSO 4 ), filtered and evaporated to give crude 16 (338 mg, 1.00 mmol, 97%).  
       EXAMPLE 17  
     (S)-2[(1-{(1R,2S,3R,4R)-3-5-fluoro-2-(2-methoxycarbonyl-ethyl)-benzyl]-7-oxa-bicyclo[2.2.1]hept-2-yl}-methanoyl)-aminol-3-hydroxy-propionic acid benzyl ester  
       [0053]    The crude acid 16 (338 mg, 1.00 mmol, ) was co-evaporated with benzene and the residue was taken into dry THF (4.3 mL, Aldrich). The solution was cooled in an ice bath and 1-hydroxybenzotriazole monohydrate (188 mg, 1.39 mmol, Aldrich), L-serine benzyl ester hydrochloride (259 mg, 1.12 mmol, Sigma), and triethylamine (0.31 mL, 2.22 mmol, Aldrich) were added. The mixture was stirred for 5 min. and then DCC (233 mg, 1.13 mmol, Aldrich) was added, rinsing the sides of the flask with 0.5 mL of THF. The mixture was allowed to slowly warm to room temperature.  
         [0054]    After 18 h, the mixture was cooled in an ice bath and ethyl acetate (4.3 mL) was added. The resulting mixture was filtered, evaporated and purified by flash column chromatography on silica gel (100% ethyl acetate) which gave slightly impure product (475 mg). Recrystallization (hexanes/ethyl acetate) gave the pure amide of Example 17 (176 mg, 0.34 mmol, 34%).  
       EXAMPLE 18  
     (S)-2-{(1R,2S,3R,4R)-3-[5-2-(2-methoxycarbonyl-ethyl)-benzyl]-7-oxa-bicyclo[2.2.1]hept-2-yl{-4,5-dihydro-oxazole-4-carboxylic acid benzyl ester  
       [0055]    PPh 3  (120 mg, 0.46 mmol, Aldrich) and i-Pr 2 NEt (82 μL, 0.47 mmol, Aldrich) were added to a solution of the amide of Example 17 (153 mg, 0.30 mmol) in dry CH 2 Cl 2  (0.26 mL, Aldrich) and dry CH 3 CN (1.0 mL, Aldrich). CCl 4  (43 μL, 0.45 mmol, Aldrich) was added dropwise and after 4 h of stirring, the solution was cooled in an ice bath and ethyl acetate (3 mL) and saturated aqueous NaHCO 3  solution (1 mL) were added. The mixture was poured into saturated aqueous NaCl solution (10 mL) and was extracted with ethyl acetate (10 mL). The organic portion was washed with saturated aqueous NaCl solution (10 mL) and then was dried (MgSO 4 ), filtered, evaporated and purified by flash column chromatography on silica gel (2:1 EtOAc/hexanes) to give the oxazoline of Example 18 (102 mg, 0.21 mmol, 69%).  
       EXAMPLE 19  
     2-{(1R,2S,3R,4R)-3-[5-fluoro-2-(2-methoxycarbonyl-ethyl)-benzyl]-7-oxa-bicyclo[2.2.1]hept-2-yl}-oxazole-4-carboxylic acid benzyl ester  
       [0056]    The oxazoline of Example 18 was co-evaporated with benzene and then taken into dry CH 2 Cl 2  (1 mL, Aldrich). The solution was cooled in an ice bath and DBU (30 μL, 0.20 mmol, Aldrich) and BrCCl 3  (19 μL, 0.19 mmol, Aldrich) were added. The solution was allowed to stand at 0° C. for 17 h and then was diluted with CH 2 Cl 2  (10 mL). The CH 2 Cl 2  solution was washed with saturated aqueous NH 4 Cl solution (2×5 mL) and the combined aqueous solution extracted with EtOAc (2×10 mL). The combined organic solution was dried (MgSO 4 ), filtered, evaporated, and purified by flash column chromatography on silica gel (40% ethyl acetate/hexanes) to give the oxazole of Example 19 (74 mg, 0.15 mmol, 75%).  
       EXAMPLE 20  
       2 -{(1R,2S,3R,4R)-3-[5-fluoro-2-(2-methoxycarbonyl-ethyl)-benzyl]-7-oxa-bicyclo[2.2.1]hept-2-yl}-oxazole4-carboxylic acid  
       [0057]    Pd(OH) 2 /C (17 mg, 20%, Aldrich) was added to a solution of the oxazole of Example 19 (74 mg, 0.15 mmol) in ethyl acetate (1.4 mL, B &amp; J brand). The mixture was stirred under a balloon of H 2(g)  for 2 h and then was filtered through celite. Evaporation of the ethyl acetate left the acid of Example 20 (63 mg, 0.16 mmol, 100%) as a white crystalline solid.  
       EXAMPLE 21  
       3 -(2-{(1R,2R,3S,4R)-3-[4-(4-Cyclohexyl-butylcarbamoyl)-oxazol-2-yl]-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl)-4-fluoro-phenyl)-propionic acid methyl ester  
       [0058]    The acid of Example 20 (26 mg, 0.064 mmol) was co-evaporated with benzene and the residue taken into dry CH 2 Cl 2  (0.3 mL, Aldrich). Dry DMF (small drop, Aldrich) was added followed by (COCl) 2  (11 μL, 0.13 mmol, Aldrich) which caused immediate gas evolution. After 30 min., the volatiles were removed and the residue co-evaporated twice with toluene to leave an off-white solid.  
         [0059]    The crude acid chloride was taken into dry CH 2 Cl 2  (0.36 mL, Aldrich) and Et 3 N (21 μL, 0.15 mmol, Aldrich) was added. 4-cyclohexylbutylammonium chloride (18 mg, 0.094 mmol) was then added and the reaction stirred for 1.5 h. The mixture was partitioned between 10 mL EtOAc and 10 mL 1 M HCl. The aqueous layer was extracted with 10 mL EtOAc and the combined EtOAc solution dried (MgSO4), filtered, evaporated, and purified by flash column chromatography on silica gel (50% EtOAc/hexanes) to give the ester of Example 21 (27 mg, 0.05 mmol, 78%) as a white solid.  
       EXAMPLE 22  
     3-(2-{(1R,2R,3S,4R)-3-[4-(4-Cyclohexyl-butylcarbamoyl)-oxazol-2-yl]-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl}-4-fluoro-phenyl)-propionic acid  
       [0060]    A solution of the ester of Example 21 (26 mg, 0.048 mmol) in THF (0.15 mL, Aldrich) and MeOH (0.75 mL, B&amp;J Brand) was treated with 1 M NaOH solution (0.29 mL, 0.29 mmol). After 17 h, The solution was partitioned between 10 mL CH 2 Cl 2  and 10 mL 1 M HCl. The aqueous layer was extracted with CH 2 Cl 2  (2×10 mL) and the combined CH 2 Cl 2  solution dried (MgSO 4 ), filtered, evaporated, and purified by flash column chromatography on silica gel (5% MeOH/CH 2 Cl 2 ) to give the oxazole of Example 22 (24 mg, 0.046 mmol, 95%) as a white solid.  
         [0061]    500 MHz  1 H NMR (CDCl 3 , ppm)δ8.13 (s, 1 H) 7.11-7.08 (m, 2 H) 6.85-6.80 (m, 2 H) 4.97 (d, J=4.4 Hz, 1 H) 4.37 (d, J=4.8 Hz, 1 H) 3.4-3.3 (m, 3 H) 2.84 (t, J=7.7 Hz, 2 H) 2.6-2.5 (overlapping m, 3 H) 2.35 (dd, J=14.5, 11.2 Hz, 1 H) 2.20 (dd, J=14.5, 4.9 Hz, 1 H) 1.9-1.1 (overlapping m, 20 H) 0.9-0.8 (m, 2 H). MS (El) m/z 526.2831 (526.2843 calculated for C 30 H 39 FN 2 O 5 ; error =2 ppm).  
       EXAMPLE 23(a)  
       [0062]    2-Thiophene-3-yl-[1,3]dioxolane was synthesized as described in Gronowitz, S.; Gestblom, B.; Mathiasson, B. Arkiv for Kemi 1963, 20, 407.  
       EXAMPLE 23(b)  
     2-(2-Bromo-thiophen-3-yl)-[1,3]dioxolane (2)  
       [0063]    A −78° C. solution of the dioxolane of Example 23(a) in dry THF (93 mL, Aldrich) was treated with n-butyllithium (34 mL, 50.7 mmol, 1.49 M/hexanes, Aldrich). The mixture was stirred at −78° C. for 35 minutes and then BrCF 2 CF 2 Br (6.1 mL, 51.1 mmol, Aldrich) was added. After 10 minutes, the mixture was allowed to warm to 0° C. and after 30 minutes at 0° C., the mixture was allowed to warm to room temperature. The solution was partitioned between H 2 O and ether (100 mL each). The layers were separated and the aqueous layer extracted with ether (100 mL). The combined ether solution was washed with 1 M sodium thiosulfate solution (2×100 mL) and brine (100 mL) and then was dried (MgSO 4 ), filtered and evaporated to leave 11.15 g of 2-(2-Bromo-thiophen-3-yl)-[1,3]dioxolane as a yellow oil that was used directly in the next step.  
       EXAMPLE 23(c)  
     2-Bromo-thiophene-3-carbaldehyde  
       [0064]    An acetone (50 mL) solution of the crude product of Example 23(b) (11.15 g) was treated with H 2 O (25 mL) and p-toluenesulfonic acid monohydrate (876 mg, 4.6 mmol, Aldrich). After 17 h, NaHCO 3  (761 mg) and H 2 O (25 mL) were added and the mixture evaporated. The residue was partitioned between ether (100 mL) and saturated NaHCO 3  solution (50 mL). The ether layer was washed with H 2 O (4×50 mL) and then was dried (MgSO 4 ), filtered and evaporated to leave a yellow solid (8.217 g). The crude product contained a few percent starting material by NMR and so was taken into 50 mL ether and treated with 3 M HCl (50 mL). The mixture was stirred vigorously for 2 h and then the layers were separated. The ether solution was washed with saturated NaHCO 3  solution (50 mL) and H 2 O ( 4×50 mL) and then was dried (MgSO   4 ), filtered and evaporated to leave 2-Bromo-thiophene-3-carbaldehyde (3) (7.902 g, 41.4 mmol, 89% for the 2 steps) as a yellow solid.  
       EXAMPLE 23(d)  
     (E)-3-(2-Bromo-thiophen-3-yl)-acrylic acid ethyl ester  
       [0065]    A solution of the aldehyde of Example 23(c) (4.334 g, 22.7 mmol) and (carboethoxymethylene)triphenylphosphorane (8.708 g, 25.0 mmol, Aldrich) in THF (40 mL) was stirred for 17 h. The solution was then evaporated, taken into ether (53 mL) and vacuum filtered. The filtrate was evaporated and the residue purified by flash chromatography on silica gel (20% ethyl acetate/hexanes) to give (E)-3-(2-Bromo-thiophen-3-yl)-acrylic acid ethyl ester 4 (5.559 g, 21.3 mmol, 94%) as a slightly yellow oil.  
       EXAMPLE 23(e)  
     3-(2-Bromo-thiophen-3-yl)-propionic acid ethyl ester  
       [0066]    A mixture of the ester of Example 23(d) (5.217 g, 20.0 mmol) and (PPh 3 ) 3 RhCl (1.56 g, 1.69 mmol, Aldrich) in ethanol (60 mL) was stirred under a balloon of H 2  for 23 h. The mixture was then filtered through celite and evaporated. The residue was purified by flash chromatography (5% ethyl acetate/hexanes→10%) to give 3-(2-Bromo-thiophen-3-yl)-propionic acid ethyl ester (4.507 g, 17.1 mmol, 85%).  
       EXAMPLE 23(f)  
     3-(2-Bromo-thiophen-3-yl)-propan-1-ol  
       [0067]    A −78° C. solution of the ester of Example 23(e) (3.896 g, 14.8 mmol) in dry toluene (30 mL, Aldrich) was treated with Dibal (21 mL, 31.5 mmol, 1.5 M/toluene, Aldrich). After 1 h, the mixture was allowed to warm to 0° C. and after a further 1 h, the reaction was quenched by addition of 6 M HCl (30 mL). The mixture was stirred for 15 min. and then was extracted with ether (50 mL). The ether solution was washed with 1 M HCl (2×30 mL) and brine (30 mL) and then was dried (MgSO 4 ), filtered, evaporated and purified by flash chromatography (20% ethyl acetate/hexanes→30%) to give 3-(2-Bromo-thiophen-3-yl)-propan-1-ol (3.224 g, 14.6 mmol, 99%).  
       EXAMPLE 24  
     3-(2-{(1R,2R,3S,4R)-3-[4-(4-Cyclohexyl-butylcarbamoyl)-oxazol-2-yl]-7-oxa-bicyclo[2.2.1]hept-2-ylmethyl}-2-thienyl)-propionic acid  
       [0068]    The above-named compound is prepared by reacting the compound of Example 23 (f) according to the method disclosed in Examples 8 through 22, with the compound of Example 23 (f) replacing alcohol 7 and in the step of Example 14, the reaction was carried out at 80° C., rather than 60° C., and, in the step of Example 20 an excess of Pd(OH)2/C was used rather than a catalytic amount.  
         [0069]    The compound of Example 24 was tested for PGF 2α  antagonist activity as follows:  
         [0070]    Ca 2+  Signaling  
         [0071]    HEK cells stably transfected with the human FP receptor were removed from the culture flasks by approximately 1 min treatment with trypsin 0.05%/0.53 mM EDTA in HBSS (Gibco, Grand Island, N.Y.) at 37° C. Proteolytic activity was arrested by adding 5 ml of 10% fetal bovine serum in DMEM. The cells were consecutively washed in Hank&#39;s BSS and medium containing 140 mM NaCl, 50 mM KCl, 1 mM MgCl 2 , 1.5 mM CaCl 2 , 10 mM HEPES: TRIS, 5 mM glucose, 5 mM Na pyruvate, 0.1% bovine serum albumin at pH 7.4: centrifugation for the washes was performed for 15 minutes at 200 g at room temperature. Cells were counted, resuspended in the above medium and incubated with 2×10 −6  M Fura 2/acetoxymethyl ester in a shaking water bath for 30 minutes at 37° C. The cells were subsequently washed in medium as above and resuspended at a concentration of 2×10 6  cells ml −1 . Aliquots of 0.5 ml cell suspension were then added to autocap microtubes to provide 10 6  cells per experimental determination of intracellular free Ca 2+  concentration ([Ca 2+ ] i ).  
         [0072]    Fluorescence was measured in a Perkin-Ehner LS-5 fluorescence spectrophotometer at excitation and emission wavelengths of 340 and 492 mn, respectively, with both slits at 10 nm. For each experimental determination 10 6  cells were washed (200×g for 5 min) and suspended in a 2 ml cuvette with buffer containing 120 mM NaCl, 6 mM KCl, 1 mM MgSO 4 , 1.5 mM CaCl 2 , 20 mM HEPES, 1 mg ml −1  glucose and 1 mg ml −1  Na pyruvate. Stirring was achieved by an overhead-mounted, paddle stirrer with the temperature maintained at 37° C. The cells were lysed with digitonin (10 μl of 100 mg ml −1  DMSO) to obtain f max . EGTA (100 mM) and sufficient 10N NaOH to adjust the pH to 8.5 were then successively added to obtain f min .  
         [0073]    As shown in the Table, below, the compound of Example 24 has PGF 2α  antagonist activity that is similar to the compound disclosed in U.S. Pat. 5,100,889 and 5,153,327, above, and shows greater PGF 2α  antagonist activity than the 1-methylester of such compound. Thus, it is to be noted that small changes, such as converting the compound of the patents to the 1-methyl ester, greatly effects activity. That is the 1-methyl ester is much less active than the corresponding acid.  
                                             STRUCTURE   K B  (FP receptor)                                                                          43.2                                             20.4                                             2410                  
 
         [0074]    The effects of the FP receptor antagonists disclosed above on the Ca2+ signal associated with FP receptor stimulation by the agonist 17-phenyl PGF 2α  are depicted in FIGS. 5 through 7. The principal of this assay is that pretreatment with an antagonist will attenuate the response to agonist: this creates a rightward displacement of the 17-phenyl PGF 2α  dose-response curve as illustrated.  
         [0075]    These compounds exert their antagonist effects by competing with agonist, in this case 17-phenyl PGF 2α  for the FP receptor.  
         [0076]    The recombinant human FP receptor has been used in these studies. It is the authenticated target FP receptor. The cat iris is not an appropriate assay for such studies for the following reasons. The cat iris is very responsive to both acidic and neutral PGF 2α  analogs and, for this reason, the above antagonist compounds exhibit much weaker activity in this preparation.  
         [0077]    The compounds of the invention can be administered orally or parenterally to various mammalian species known to be subject to PGF 2α -mediated disease responses, e.g., humans, cats, dogs and the like in an effective amount within the dosage range of about 0.1 to about 100 mg/kg, preferably about 0.2 to about 50 mg/kg and more preferably about 0.5 to about 0.5 to about 25 mg/kg (or from about 1 to about 2500 mg, preferably from about 5 to about 2000 mg) on a regimen in single or 2 to 4 divided daily doses.  
         [0078]    The active ingredient can be utilized in a composition such as tablet, capsule, solution or suspension containing about 5 to about 500 mg per unit of dosage of a compound or mixture of compounds of formulas I, II or III in topical form for wound healing, etc. (0.01 to 5% by weight compound of formulas I, II or III, 1 to 5 treatments per day). They may be compounded in conventional matter with a physiologically acceptable vehicle or carrier, excipient, binder, preservative, stabilizer, flavor, etc., or with a topical carrier such as mineral oil as called for by accepted pharmaceutical practice.  
         [0079]    The compounds of the invention can be administered orally or parenterally to various mammalian species known to be subject to PGF 2α -mediated disease responses, e.g., humans, cats, dogs and the like in an effective amount within the dosage range of about 0.1 to about 100 mg/kg, preferably about 0.2 to about 50 mg/kg and more preferably about 0.5 to about 0.5 to about 25 mg/kg (or from about 1 to about 2500 mg, preferably from about 5 to about 2000 mg) on a regimen in single or 2 to 4 divided daily doses.  
         [0080]    The active ingredient can be utilized in a composition such as tablet, capsule, solution or suspension containing about 5 to about 500 mg per unit of dosage of a compound or mixture of compounds of formulas I, II or III in topical form for wound healing, etc. (0.01 to 5% by weight compound of formulas I, II or III, 1 to 5 treatments per day). They may be compounded in conventional matter with a physiologically acceptable vehicle or carrier, excipient, binder, preservative, stabilizer, flavor, etc., or with a topical carrier such as mineral oil as called for by accepted pharmaceutical practice.  
         [0081]    The compounds of the invention may also be administered topically to treat peripheral vascular diseases and as such may be formulated as a cream or ointment.  
         [0082]    The foregoing description details specific methods and compositions that can be employed to practice the present invention, and represents the best mode contemplated. However, it is apparent for one of ordinary skill in the art that further compounds with the desired pharmacological properties can be prepared in an analogous manner, and that the disclosed compounds can also be obtained from different starting compounds via different pharmaceutical compositions may be prepared and used with substantially the same result. Thus, however detailed the foregoing may appear in text, it should not be construed as limiting the overall scope hereof; rather, the ambit of the present invention is to be governed only by the lawful construction of the appended claims.