反应详情

A mixture of 460 mg of ethyl 4-(t-butoxycarbonylamino)-2-hydroxybenzoate, 300 mg of cyclopentanol, 1.5 g of diethyl azodicarboxylate (40% solution in toluene), 900 mg of triphenylphosphine and 10 ml of tetrahydrofuran was stirred at room temperature for 3 days. The solvent was evaporated and the residue was purified by the silica gel chromatography (ethyl acetate/hexane) to obtain crude ethyl 4-(t-butoxycarbonylamino)-2-cyclopentyloxybenzoate. A mixture of this crude product, 20 ml of ethanol and 5 ml of 1 M aqueous sodium hydroxide solution was stirred at room temperature overnight. After the treatment with ethyl acetate as the extracting solvent in an ordinary manner, the title compound was obtained.

1. customThe solvent was evaporated
2. customthe residue was purified by the silica gel chromatography (ethyl acetate/hexane)