摘要 |
Compounds of general formula (I) <IMAGE> (I) (where R1 is a carboxyl group, a group COO(-) or a blocked carboxyl group; R2 is an amino or protected amino group; and R is hydrogen or a group of the formula CH2X, where X represents a halogen atom, a hydroxyl group, an acetoxy group; a group of the formula O.CO.NHR3, where R3 is hydrogen, a C1-4 alkyl group optionally substituted by 1 to 3 halogen atoms or an N-protecting group; a group of the formula OR4, where R4 is a C1-4 alkyl group optionally substituted by halogen or a C1-4 alkoxy group; or a pyridinium, 3-carbamoyl-pyridinium or 4-carbamoyl-pyridinium group; B is -S- or -SO- ( alpha - or beta -); and the dotted line bridging the 2-, 3- and 4- positions indicates that the compound is a ceph-2-em or ceph-3-em compound) and salts thereof, the compounds of formula (I) being associated with an anion when X represents a pyridinium, 3-carbamoylpyridinium group or a 4-carbamoylpyridinium group and R1 is other than COO(-)) are disclosed. Processes for their preparation and pharmaceutical compositions containing them are also disclosed. |