Ammonium Chloride → 3-Benzyloxy-5-bromo-4-[hydroxyl(4-methoxyphenyl)methyl]-1-isopropyl-1H-pyrazole

3-Benzyloxy-5-bromo-4-formyl-1-isopropyl-1H-pyrazole (0.7 g) was dissolved in tetrahydrofuran (5 mL), and a solution of 4-methoxyphenylmagnesium bromide in tetrahydrofuran (0.5 mL/L, 4.3 mL) was added to the stirred solution. The mixture was stirred at room temperature for 1 hour. A small amount of a saturated ammonium chloride aqueous solution was added to the reaction mixture, and the mixture was purified by column chromatography on aminopropylated silica gel (eluent: tetrahydrofuran) to give the title compound (0.6 g).