METHOD FOR PREPARING NEW CARBOXYLIC ACID ESTERS ACTIVE UNDER THE PHARMACEUTICAL SITE AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

摘要

Novel esters of pharmacologically active carboxylic acids, which can be cleaved under physiological conditions, in particular of antibiotically active carboxylic acids from the beta -lactam antibiotic field, are described, which are characterised in that the alcohol component of the ester is a group of the general formula IMAGE in which R1 denotes hydrogen or lower alkyl, R2 denotes hydrogen, lower alkyl, lower haloalkyl, lower alkenyl, lower alkoxycarbonyl, aryl or heteroaryl or, together with R1 denotes lower alkylene, R3 denotes hydrogen, lower alkyl or lower alkoxycarbonyl, R4 denotes the group -COOR5, -COR6, -SO2-R6, -CONR7R8 or -PO(OR9)2, R5 denotes a saturated or unsaturated hydrocarbon radical having up to 12 carbon atoms, in which up to two methylene groups can be replaced by oxygen atoms, or denotes aryl or aryl-lower alkyl, R6 denotes lower alkyl or aryl, R7 and R8 each denotes hydrogen or lower alkyl or together denotes lower alkylene in which a methylene group can be replaced by an oxygen or sulphur atom or by an imino or lower alkylimino group, and R9 denotes lower alkyl. If a basic substituent is present, these esters can also be present in the form of pharmaceutically acceptable acid addition salts.