Process for the preparation of novel polypeptide derivatives

摘要

There are prepared novel compounds of the formula <IMAGE> in which R1, R2, R3 and Z have the meanings given in Patent Claim 1, B represents -Gly-, -D-Ala-, -Sar- or -Pro-, D represents -Phe-, -D-Phe-, -Tyr(R3CO)- or -D-Tyr(R3CO)-, and E represents one of the amino acid, amino acid amide, amino acid ester or esterified amino alcohol radicals defined in Patent Claim 1. The process is based on esterification of the corresponding polypeptide derivatives containing free OH groups. These compounds can be used for the relief of pains of all sorts of origin.