| abstract |
Process for the preparation of beta-lactam derivatives corresponding to formula (I), in which R1 represents hydrogen or a metal salt; and R2 represents hydrogen, acetoxymethyl, (2,5-dihydro-2-methyl-6-hydroxy-5-oxo-as-triazin-3-yl) thiomethyl or (1-methyl-1H-tetrazol-5-yl) thiomethyl . The method consists in (a) putting triphenylphosphine and hexachloroethane or carbon tetrachloride in reaction with acetic acid 2- (2-aminothiazol-4-yl) -2-syn-methoxyimino, in order to d '' obtaining the corresponding acyloxyphosphonium chloride derivative and corresponding to formula (II); and (b) acylating a previously silylated derivative of 7-ACA using said acyloxyphosphonium chloride derivative without isolating it. |