Sodium hydride (440 mg) was suspended in dimethylformamide (10 ml), and 1,2,4-triazole (948 mg) was added to the suspension, to which a solution of 1-(2,4-difluorophenyl)-1-(6-cyanobenzothiazol-2-yl)-2-chloroethanol (1.49 g) in dimethylformamide (10 ml) was added. The mixture was heated at 60° C. for 4 hours. After the liquid reaction mixture was cooled to room temperature, ethyl acetate and water were added thereto. An organic layer separated was washed three times with water and then dried over magnesium sulfate, and the solvent was distilled out. The residue was recrystallized from dichloromethanediisopropyl ether to obtain the intended compound (1.17 g). Melting point: 170°-172° C.
