HCID 56990923, compound → HCID 70618367, compound

Participants

Reaction Conditions

Reaction Steps

Water (445 ml) is added dropwise to a solution of N,S-ditrityl-cysteinyl-tyrosyl-phenylalanine methyl ester (21.9 g, 23.5 mmoles, described in Example 1) in glacial acetic acid (1780 ml) at room temperature. The solution is stirred at 45° C for 1.5 hour and diluted with water (2200 ml). The precipitate is removed by filtration and the filtrate is evaporated. The last traces of acetic acid are removed by repeated evaporation with benzene to give (S-trityl)cysteinyl-tyrosyl-phenylalanine methyl ester.

Provenance & Evidence