1-Hydroxybenzotriazole → ethyl ({4-[(3R,4S)-3-({(tert-butoxycarbonyl) [(1R)-1-(1-naphthyl)ethyl]amino}methyl)-4-phenylpyrrolidin-1-yl]-4-oxobutanoyl}amino)acetate

Participants

Reaction Steps

A mixture of 350 mg of the crude 4-[(3R,4S)-3-({(tert-butoxycarbonyl)[(1R)-1-(1-naphthyl)ethyl]amino}methyl)-4-phenylpyrrolidin-1-yl]-4-oxobutanoic acid obtained in Example 9 (1), 101 mg of glycine ethyl ester hydrochloride, 45 mg of HOBt, 73 mg of triethylamine and 5 ml of dichloromethane was mixed with 190 mg of WSC hydrochloride and stirred at room temperature for 2 days. The reaction solution was concentrated under a reduced pressure, and the thus obtained residue was purified by a silica gel column chromatography (chloroform-ethyl acetate) to obtain 315 mg of ethyl ({4-[(3R,4S)-3-({(tert-butoxycarbonyl) [(1R)-1-(1-naphthyl)ethyl]amino}methyl)-4-phenylpyrrolidin-1-yl]-4-oxobutanoyl}amino)acetate as a colorless oily substance.

Provenance & Evidence