Penem derivatives, their preparation and pharmaceutical compositions

Abstract

Penem derivatives of general formula (I), below, and pharmaceutically acceptable salts thereof are disclosed. ##STR1## wherein: R.sub.1 is H, C.sub.1 -C.sub.6 alkoxy, C.sub.3 -C.sub.7 cycloalkyl, or an optionally protected C.sub.1 -C.sub.6 hydroxyalkyl; R.sub.2 is a free or esterified carboxyl group or a carboxylate anion; R.sub.3 is H or C.sub.1 -C.sub.6 alkyl; R.sub.4 is H, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 hydroxyalkyl, C.sub.1 -C.sub.6 mercaptoalkyl, C.sub.1 -C.sub.6 aminoalkyl, C.sub.1 -C.sub.6 alkyl substituted by a quaternary ammonium group, C.sub.1 -C.sub.6 carboxyalkyl, cycloalkyl, aryl, arylalkyl, heterocyclyl-alkyl optionally substituted, saturated or unsaturated heterocycle, or R.sub.3 and R.sub.4 are linked together to form a heterocyclic ring having 3-7 atoms; R.sub.5 and R.sub.6 independently are H, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 hydroxyalkyl, C.sub.1 -C.sub.6 mercaptoalkyl, C.sub. -C.sub.6 aminoalkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylaryl, heterocyclyl-alkyl, C.sub.1 -C.sub.6 alkyl carboxyamide, or R.sub.5 and R.sub.6 are taken together to form a heterocyclic ring having 3-7 atoms, and n is an intiger from 1 to 3.