In a solution of 151 mg of 2-amino-1-(3,5-dichloropyridin-2-yl)ethanone-O-propyloxime and 86 mg of triethylamine in 4 ml of dichloromethane, 154 mg of 2-(trifluoromethyl)benzoyl chloride was added dropwise with stirring under cooling with ice, and after the addition, the mixture was stirred at room temperature for another 2 hours. After completion of the reaction, the reaction mixture was mixed with 10 ml of water and extracted with chloroform (30 ml×1), the resulting organic layer was washed with water (10 ml×1) and dried over saturated aqueous sodium chloride and then anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography using ethyl acetate-hexane (with a gradient of from 2:8 to 3:7) as the eluent to obtain 218 mg of the desired product as a pale yellow resinous substance.
