To a stirring solution of DMF (5 mL) containing 4-(aminomethyl)-6-bromo-1-(4-methoxybenzyl)-4-(trifluoromethyl)-3,4-dihydroquinazolin-2(1H)-one (710 mg, 1.60 mmol), 4-fluorobenzoic acid (246 mg, 1.76 mmol), hydroxybenzotriazole monohydrate (245 mg, 1.60 mmol) and triethylamine (0.22 mL, 1.6 mmol) at 0° C., 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (368 mg, 1.9 mmol) was added little by little thereto. After the reaction solution was stirred overnight at room temperature, water was slowly added thereto under stirring. After a solid began to precipitate, further excess water was added thereto, and the mixture was stirred at room temperature for 2 hours. The solid was collected by filtration and washed with water and then dried under reduced pressure, whereby the objective compound (815 mg, 90%) was obtained as a white solid.
