| abstract |
New cephalosporins are described. These bear on the exomethylene group in the 3-position of the cephem ring a substituted or unsubstituted aryl, acylamino, triazolyl or tetrazolyl group or a substituted or unsubstituted aromatic heterocyclic group, wherein the aromatic heterocyclic group is attached via a carbon-carbon bond and wherein the triazolyl group or the tetrazolyl group is attached via a carbon-nitrogen bond. Further, the new cephalosporin at the amino group in the 7-position bears the following group (see patent). In this group, A represents the group of formula -CH 2 - or a group of formula I in which R 5 represents a hydrogen atom or an alkyl group and in which the bond denotes the syn or anti isomer or mixture thereof , Further, in this group, R 3 represents a hydrogen atom or a halogen atom and R 4 represents a hydrogen atom or an optionally protected or substituted amino group. |