SYNTHESIS OF N,N'-CARBONYL-BIS-AMINO ACIDS AND N,N'-CARBONYL-BIS-PEPTIDES

A new method for the preparation of N,N'-carbonyl-bis-amino acid eater s by reaction of bis(4-nitrophenyl)carbonate with amino acid eaters is described. When the carbonate reacts with two equivalents of a peptid e eater, N,N'-carbonyl-bis/peptide ester) is obtained but a hydantoin derivative is formed as a side product. The hydantoin derivative is a major product, when equimolar amounts are allowed to react. Usefulness of this method for preparation of larger N,N'-carbonyl-bis-peptides i s demonstrated by the synthesis of the respective product from C-termi nal hexapeptide of Substance P linked to the Merrifield resin.