Triphenylphosphine → ethyl 2-[4-[((2R)-2-tert-butoxycarbonylamino-1-butyl)oxy]phenyl]-3-(5-cyano-2-benzofuranyl)propionate

Participants

Reaction Steps

In 300 ml of tetrahydrofuran were dissolved 1.1 g of ethyl 3-(5-cyano-2-benzofuranyl)-2-(4-hydroxyphenyl)propionate, 1.24 g of (2R)-2-tert-butoxycarbonyl-amino-1-butanol and 1.72 g of triphenylphosphine. The thus prepared solution was mixed with 1.14 g of diethyl azodicarboxylate and stirred at room temperature for 18 hours. The resulting solution was further mixed with 0.83 g of (2R)-2-tert-butoxycarbonylamino-1-butanol, 1.2 g of triphenylphosphine and 0.76 g of diethyl azodicarboxylate, and the mixture was stirred at room temperature for 18 hours. After concentrating the thus prepared reaction solution to dryness, the resulting residue was purified by subjecting it to silica gel column chromatography using a toluene/ethyl acetate mixture as a developing solvent, thereby obtaining 660 mg of ethyl 2-[4-[((2R)-2-tert-butoxycarbonylamino-1-butyl)oxy]phenyl]-3-(5-cyano-2-benzofuranyl)propionate in a colorless and oily form.

Provenance & Evidence