To a solution of 120 mg of N-[2-(3-chloro-5-methoxypyridin-2-yl)-2-oxoethyl]phthalimide and 60 mg of methoxyamine hydrochloride in 5 ml of ethanol, 85 mg of pyridine was added, and the mixture was stirred at 80° C. for 6 hours. After completion of the reaction, the solvent was evaporated under reduced pressure, and the resulting residue was purified by silica gel column chromatography using ethyl acetate-hexane (with a gradient of from 1:9 to 3:7) as the eluent to obtain 101 mg of the desired product as a pale yellow oil.
