Benzyloxycarbonyl-asparagine → N2 [3(S)-[[N-(benzyloxy carbonyl)-L-asparaginyl]amino]-4-(4-tert.butoxyphenyl)-2(R)-hydroxybutyl]-N1-tert.butyl-L-prolinamide

Participants

Reaction Steps

A solution of 1.58 g of N2 -[3(S)-(benzyloxyformamido)-4-(4-tert.butoxyphenyl)-2(R)-hydroxybutyl]-N1 -tert.butyl-L-prolinamide in 200 ml of ethanol was hydrogenated over 100 mg of 10% palladium-on-carbon for 4 hours. The catalyst was removed by filtration and the filtrate was evaporated to give an oil which was coupled with 0.74 g of N-(benzyloxycarbonyl)-L-asparagine in a manner analogous to that described in Example 1. The crude product was chromatographed on a column of silica gel using 10% methanol in dichloromethane for the elution. There was obtained 0.59 g of N2 -[3(S)-[[N-(benzyloxycarbonyl)-L-asparaginyl]amino]-4-(4-tert.butoxyphenyl)-2(R)-hydroxybutyl]-N1 -tert.butyl-L-prolinamide as a white solid; MS: m/e 654 [M+H]+.

Provenance & Evidence