反应详情

For the preparation of the ester starting material, MS: 756 (15, M+H), N-(benzyloxycarbonyl)-3-(p-cyanophenyl)-DL-alanine and N-(m-aminobenzoyl)-β-alanine benzyl ester trifluoroacetate are coupled to give N-[m-[[N-(benzyloxycarbonyl)-3-(p-cyanophenyl)-DL-alanyl]amino]benzoyl]-β-alanine benzyl ester, MS: 605 (15, M+H), and this is converted with hydrogen sulphide and triethylamine in pyridine into N-[m-[[N-(benzyloxycarbonyl)-3-[p-(thiocarbamoyl)phenyl]-DL-alanyl]amino]benzoyl]-β-alanine benzyl ester, m.p. 145°-146° C. (from ethyl acetate). The latter is then reacted with methyl iodide in acetone and subsequently with ammonium acetate in methanol and treated with benzyl chloroformate and triethylamine in THF.