To a solution of 4-nitro-N-methyl-N-[2-(3-aminoprop-1-yloxy)phenyl]benzamide (422 mg) and triethylamine (130 mg) in dichloromethane (10 ml) was added phenyl chloroformate (201 mg) and the solution was stirred at 0° C. for 30 minutes. The reaction mixture was diluted with dichloromethane and then the organic solution was washed successively with 1N hydrochloric acid, saturated sodium bicarbonate aqueous solution and brine. Drying, filtering and removal of solvents afforded a crude product. The crude product was chromatographed on silica gel (eluent; 1% methanol in chloroform) to give 4-nitro-N-methyl-N-[2-(3-phenoxycarbonylaminoprop-1-yloxy)phenyl]benzamide (383 mg) as a slightly yellow oil.
