Fremgangsmåde til fremstilling af urethanbeskyttede alfa-aminosyre-N-carboxyanhydrider

Production of urethane-protected N-carboxyanhydrides of alpha-aminoacids (I) comprises reacting unprotected anhydrides of alpha-aminoacids (II) with organic dicarbonates (III) in an organic solvent with melting point below -20[deg]C in presence of a catalytic amount of 1,4-diazabicyclo[2.2.2]octane. Production of urethane-protected N-carboxyanhydrides of alpha-aminoacids of formula (I) comprises reacting unprotected anhydrides of alpha-aminoacids of formula (II) with at least 1 mol equivalent. of a dicarbonate of formula R 3>-O-CO-O-CO-O-R 3>(III) in presence of a catalytic amount of 1,4-diazabicyclo[2.2.2]octane (triethylenediamine, TEDA), in an organic solvent with a melting point below -20[deg]C. [Image] R 1>, R 2>H or a side chain of a natural or synthetic alpha -aminoacid (optionally with functional groups protected); R 3>optionally unsaturated 1-10C alkyl, or 7-14C aralkyl or alkylaryl.