To a 50 mL round-bottomed flask was added 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid (171 mg, 0.77 mmol) [prepared according to the procedure of Example 151], 2-[(2S)-2-amino-3-(2,5-difluorophenyl)propyl]-1H-isoindole-1,3(2H)-dione (270 mg, 0.77 mmol) [prepared according to the procedure of Preparation 18 except substituting 2,5-difluoro-L-phenylalanine (3.02 g, 15.0 mmol) for 2,6-difluoro-L-phenylalanine] and PyBrop (436 mg, 0.93 mmol) in chloroform (7.5 mL). DIEA (680 μL, 3.89 mmol) was added and the reaction stirred overnight at room temperature. The mixture was adsorbed onto silica and purified via column chromatography (25-70% EtOAc/Hex) affording the title compound (246 mg, 0.44 mmol, 52%): LC-MS (ES) m/z=521 (M+H)+.
