Production of semi-synthetic .beta.-lactam antibiotics

Abstract

In the production of a semi-synthetic .beta.-lactam antibiotic by reacting an amino compound of the formula ##STR1## in which X is the remaining members of a ring of a .beta.-lactam antibiotic, and R is a hydrogen atom or a methoxy group, with an activated carboxylic acid derivative of the formula ##STR2## in which R.sub.1 is an organic radical, B is an optionally substituted phenyl, cyclohexadienyl or heterocyclyl radical and R.sub.2 is a lower alkyl radical, the improvement which comprises effecting the reaction in an acetone/water mixture which contains acetone and water in a volume ratio of about 0.5:1 to 3:1. Advantageously the reaction is carried out at about -10.degree. to +10.degree. C. in the presence of an organic base employing about 1.1 to 1.2 mols of the amino compound per mol of the activated carboxylic acid derivative.

Dependencies are inferred from the claim text.