HETEROMONOCYCLIC AND HETEROBICYCLIC DERIVATIVES OF UNSATURATED 7-ACYLAMIDO-3-CEPHEM-4-CARBOXYLIC ACID AND PROCESS FOR THEIR PREPARATION

This invention relates to a compound of formula (I) (I) and their pharmaceutically or veterinarily acceptable salts, wherein A is-CH=CH-, Z is cyano, carbamoyl or -COOR in which R is hydrogen or C1-C6 alkyl, X is a free or esterified carboxy group, and B is (1) a tetrazolyl radical substituted by (a') C2-C4 alkyl or (b') -(CH2)n-COOR wherein n is zero or an integer of 1 to 3 and R is as defined above; (2) a thiadiazolyl radical substituted by -NH2; or (3) a tetrazolopyridazinyl radical which is unsubstituted or is substituted by one or more substituents selected from (a") -COOR, wherein R is as defined above, and (b") amino which is unsubstituted or is substituted by a -(CH2)n-COOR group wherein n and R are as defined above. It also relates to a process for the preparation of new compounds by the application of known methods. The compounds of formula (I) together with their pharmaceutically and veterinarily acceptable salts possess a high antibacterial activity in animals and humans against both Gram-positive and Gramnegative bacteria.