To a mixture of 2-phenylaminobenzoxazole-6-acetic acid(0.067 g), methyl 2-methyl-3-(2-methoxy-5-aminophenoxy)butyrate(0.057 g), hydroxybenzotriazole (0.067 g), and N-methylmorpholine(0.05 ml) in dimethylformamide(0.25 ml) was added 1-(3-dimethylaminopropyl)3-ethylcarbodiimide hydrochloride(0.095 g). The resultant mixture was stirred for 48 hrs then added to water and extracted with ethyl acetate. The organic layer was separated, washed with aqueous acetic acid, brine, aqueous sodium bicarbonate (2 times), dried and evaporated to dryness. The residue was purified by purified by chromatography on silica using an increasingly polar mixture of ethyl acetateldichloromethane and the appropriate fraction yielded, after evaporation to dryness, a solid which was triturated with a mixture of diethylether/hexane to give the product (0.08 g) as a purple-pink solid.
