CEPHALOSPORINS AND INTERMEDIATES;PHARMACEUTICAL COMPOSITIONS

摘要

Novel cephalosporins which has attached to the exomethylene group at the 3-position of the cephem ring a substituted or unsubstituted aryl, acylamino, aromatic heterocyclic, triazolyl or tetrazolyl group, said aromatic heterocyclic group being attached through a carbon-carbon bond and said triazolyl or tetrazolyl group being attached through a carbon-nitrogen bond, and has the following group attached to the amino group at the 7-position: wherein A represents a group of the formula, -CH2- or a group of the formula in which R5 represents a hydrogen atom or an alkyl group, and the bond represents syn or anti isomer or their mixture; R3 represents a hydrogen or halogen atom; and R4 represents a hydrogen atom or an amino group which may be protected or substituted. These cephalosporins have a broad antibacterial spectrum, are stable against beta -lactamase produced by bacteria, have a low toxicity, and are well absorbed when administered orally or parenterally.