Improvements in or relating to beta lactam production

摘要

A process for the production of an 6-alpha-aminoacyl-penicillin or 7-alpha-aminoacyl-desacetoxy-cephalosporin comprising the steps (i) producing a mixed carboxylic acid anhydride by reaction of an N-substituted vinyl alpha-amino acid with an appropriate acylating agent in a methyl-(C2-4)alkyl ketone, di-(C2-4)alkyl ketone, (C1-3) alkanoic acid butyl ester or an aromatic hydrocarbon as a solvent, (ii) reacting the mixed carboxylic acid anhydride obtained in step (i) with a solution or a suspension of 6-APA or derivative thereof in non-halogenated solvent, and (iii) isolating a 6-alpha-aminoacyl-penicillin or a 7-alpha-aminoacyl-desacetoxycephalosporin obtained by adding water to the reaction mixture obtained in step (ii) to form a two-phase system and isolating a 6-alpha-aminacyl penicillin or 7-alpha-aminoacyl-desacetoxy-cephalosporin obtained by separating the aqueous phase from the organic phase.