A General Method for the Synthesis of (Carbamoylmethylene)amino Pseudopeptides

Article abstract of DOI:10.1021/jo00092a019

A general procedure for the preparation of (carbamoylmethylene)amino pseudopeptides from the corresponding (cyanomethylene)amino analogues, compatible with peptide bonds and with the usual amino and carboxyl protecting groups, is described.This procedure involves the oxidative hydration of (cyanomethylene)amino pseudopeptides with basic hydrogen peroxide under phase-transfer conditions, using n-tetrabutylammonium hydrogen sulfate as catalyst.In the basic medium of this reaction the methyl esters of (carbamoylmethylene)amino pseudodipeptides cyclized to 2,6-dioxopiperazine analogues.