A solution of 3-cyclopentyl-2-(4-fluoro-3-trifluoromethyl-phenyl)-propionic acid (304 mg, 1.0 mmol) in methylene chloride (10 mL) was cooled to 0° C. and then treated with a 2.OM solution of oxalyl chloride in methylene chloride (0.6 mL, 1.2 mmol) and a few drops of N,N-dimethylformamide. The reaction mixture was stirred at 0° C. for 15 min and at 25° C. for 24 h. The reaction mixture was then treated with 2-amino-thiazole (175 mg, 1.75 mmol) and N,N-diisopropylethylamine (0.4 mL, 2.41 mmol). This solution was stirred at 25° C. for 48 h. At this time, the reaction was concentrated in vacuo. High pressure liquid chromatography (Chromegasphere SI-60, 10 μM, 60Å, 25 cm×23 cm ID, 60/40 heptane/ethyl acetate) afforded 3-cyclopentyl-2-(4-fluoro-3-trifluoromethyl-phenyl)-N-thiazol-2-yl-propionamide (326 mg, 84.5%) as a light yellow solid: mp 125-127° C.; EI-HRMS m/e calcd for C18H18F4N2OS (M+) 386.1076, found 386.1086.
