In a round bottom flask under argon was placed 2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4,4-difluoro-butyric acid (166 mg, 0.50 mmol) and 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-1H-pyrazol-3-ylamine (prepared as in Example 49, 118 mg, 0.60 mmol) in N,N-dimethylformamide (4 mL). To this mixture was added N,N-diisopropyethylamine (250 μL, 1.5 mmol) and (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (330 mg, 0.75 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 then concentrated with silica gel (2 g). Purification by Biotage flash chromatography (Aspire 40 g column, 80% ethyl acetate/hexanes) afforded 2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-N-[1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-1-H-pyrazol-3-yl]-4,4-difluoro-butyramide (185 mg, 72%) as a cream colored foam: HR-ES-MS m/z calculated for C23H25N4O5ClF2 [M+H]+ 511.1555, observed 511.1555.
