The preparation of N-carboxyanhydrides of α-amino acids using bis(trichloromethyl)carbonate

A synthesis of the N-carboxyanhydrides (NCA's) of several α-amino acids using bis(trichloromethyl) carbonate, 1, is reported. The triphosgene is used to supply phosgene in situ in stoichiometric amounts; it is particularly effective for preparing NCA's of amino acids with long, aliphatic side chains.