UN PROCEDIMIENTO PARA LA PREPARACION DE ACIDOS METIL-2 O 3- CEFEM-4-CARBOXILICOS 3-SUSTITUIDOS.

摘要

Compounds of the formula: in which A denotes -S- or &rdurule& S->O, R<1> denotes hydrogen or acyl and R<2> denotes alkyl or a heterocyclic group, and their salts and esters are obtained from a corresponding compound of the formula: in which Y denotes a heteroaromatic group which contains an amine oxide group in the ring and is bonded via a carbon atom adjacent to the nitrogen atom, or a salt or an ester thereof by reaction with a thiol R<2>-SH in the presence of a metal compound which is able to enter into a chelate bond with the compound of the formula V. The ring sulphoxides obtained can be reduced to sulphur compounds (A= -S-), and the salts and esters obtained can be converted into free carboxylic acids. The compounds are antibacterially active.