Process for the preparation of penicillins

摘要

Penicillins of formula and non-toxic salts thereof, wherein R is a substituted or unsubstituted phenyl or heterocyclic group, are prepared by treating a N-protected penicillin of formula wherein R is as hereinbefore defined and X and Y are the same or different and are each a hydrogen or halogen atom or a C1- 5 alkyl or C1- 5 alkoxy, with a salt of a heavy metal in acqueous or partly acquoeus solution at a pH of 1 to 7. Cupric acetate at pH 3.0 is referred to. The N-protected penicillin is prepared by reacting 6-aminopenicillanic acid or a salt thereof in acqueous or anhydrous media with a reactive derivative of a carboxylic acid of formula wherein R, X and Y have the above meanings. A typical N-protected penicillin is sodium 6-(D - a - quinol - 8 - yloxycarbonylamino - a - phenylacetamino -penicillanate. D - a - quinol - 8 - yloxycarbonylamino - a - phenylacetic acid is prepared by treating D - (-) a - amino - a - phenylacetic acid with di-quinol-8-yl carbonate.