5-Cyano-2-methoxybenzoic acid (0.73 g) obtained in step A, and 16 μL of N,N-dimethylformamide were dissolved in 18 mL of dichloromethane, and the solution was cooled to 0° C. To this solution, 0.54 mL of oxalyl chloride was added little by little, and the mixture was stirred for 2.7 hours at room temperature. The reaction mixture was distilled under reduced pressure, and dried to obtain a light yellow solid. This solid was added, with the use of 10 mL of tetrahydrofuran, to a solution of 0.95 g of 4-trifluoromethoxy-2-chloroaniline and 2.1 mL of N,N-diisopropylethylamine dissolved in 20 mL of tetrahydrofuran. The mixture was stirred overnight at room temperature, and then tetrahydrofuran was distilled off under reduced pressure. The resulting solid was purified by silica gel column chromatography using methylene chloride as an elution solvent, thereby obtaining 1.37 g (90%) of 5-cyano-N-(4-trifluoromethoxy-2-chlorophenyl)-2-methoxybenzamide.
