Polypeptides. Part V. The use of t-butyl 2,4,5-trichlorophenyl carbonate in the synthesis of N-t-butoxycarbonyl amino-acids and their 2,4,5-trichlorophenyl esters
作者:Wallace Broadbent、J. S. Morley、B. E. Stone
DOI:10.1039/j39670002632
日期:——
t-Butyl2,4,5-trichlorophenylcarbonate, conveniently prepared from phosgene in two stages, reacts cleanly with amino-acids in the presence of bases to give N-t-butoxycarbonylamino-acids (and 2,4,5-trichlorophenol) in excellent yield. By co-extraction of the N-t-butoxycarbonylamino-acid and 2,4,5-trichlorophenol from the acidified reaction mixture, followed by treatment of the extracts with NN′-