A solution of (S)-2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4,4-difluoro-pentanoic acid (117 mg, 0.34 mmol) and 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-1H-pyrazol-3-ylamine (prepared as in Example 49, 82 mg, 0.42 mmol) in N,N-dimethylformamide (3 mL) was treated with N,N-diisopropyethylamine (170 μL, 1.02 mmol) and (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (225 mg, 0.51 mmol) and stirred overnight at 25° C. After this time, the mixture was diluted with ethyl acetate (25 mL) and washed with a saturated aqueous solution of ammonium chloride (25 mL), saturated aqueous solution of sodium bicarbonate (25 mL) and a saturated aqueous solution of sodium chloride (25 mL) dried over sodium sulfate and concentrated with silica gel (2 g). Purification by Biotage flash chromatography (Aspire 40 g column, 20% ethyl acetate/hexanes) afforded (S)-2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4,4-difluoro-pentanoic acid [1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-1H-pyrazol-3-yl]-amide (72 mg, 40%) as a white foam: HR-ES-MS m/z calculated for C24H27N4O5ClF2 [M+Na]+ 547.1530, observed 547.1531.
