Cesium carbonate → ethyl 5-[2-fluoro-4-(2-methoxy-3,5-dimethylpyridin-4-yl)phenyl]-1-[(S)-tetrahydrofuran-3-yl]-1H-pyrazole-4-carboxylate

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Reaction Steps

Water (170 mL), 4-iodo-2-methoxy-3,5-dimethylpyridine obtained in Preparation Example 29(3) (35.6 g), Pd(PPh3)4 (6.52 g) and cesium carbonate (110 g) were added to a solution of ethyl 5-[2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1-[(S)-tetrahydrofuran-3-yl]-1H-pyrazole-4-carboxylate obtained in Preparation Example 6 (51.9 g) in 1,4-dioxane (500 mL), and the reaction mixture was reacted at 110° C. for six hours. The reaction mixture was returned to room temperature, and the organic layer was then separated. The organic layer was concentrated under reduced pressure. The aqueous layer, ethyl acetate (700 m) and water (100 mL) were added to the resulting residue, and the organic layer was separated. The aqueous layer was re-extracted with ethyl acetate (50 mL). The combined organic layers were sequentially washed with water and brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by NH silica gel column chromatography (ethyl acetate/n-heptane, 5% to 14%). The product was then purified again by NH silica gel column chromatography (ethyl acetate/n-heptane, 2% to 10%) to give the title compound (435 g).

Provenance & Evidence