To a 50 mL round-bottomed flask was added 4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid (222 mg, 0.80 mmol) [prepared according to the procedure of Example 146], 2-[(2S)-2-amino-3-(2,4-difluorophenyl)propyl]-1H-isoindole-1,3(2H)-dione (331 mg, 0.78 mmol) [prepared according to the procedure of Preparation 18 except substituting 2,5-difluoro-L-phenylalanine (1.0 g, 4.97 mmol) for 2,6-difluoro-L-phenylalanine] and PyBrop (448 mg, 0.96 mmol) in chloroform (10 mL). DIEA (700 μL, 4.01 mmol) was added and the reaction stirred overnight at room temperature. The reaction mixture was adsorbed onto silica and purified via column chromatography (25-75% EtOAc/Hex) affording the title compound (249 mg, 0.36 mmol, 46%): LC-MS (ES) m/z=507 (M+H)+.
