Abstract: Cephalosporin compounds having a 3-position substituent of the formula (I) are described:--CH.sub.2 --S--Q--(Y).sub.n --Pwherein Q is a 5- or 6-membered heterocyclic ring, P is a benzene ring substituted by groups R.sup.1 and R.sup.2 which are ortho with respect to one another, wherein R.sup.1 is hydroxy or an in vivo hydrolysable ester thereof and R.sup.2 is hydroxy, an in vivo hydrolysable ester thereof, carboxy, sulpho, hydroxymethyl, methanesulphonamido or ureidos; or P is a group of the formula (II) or (III): ##STR1## wherein M is oxygen or a group NR.sup.3 wherein R.sup.3 is hydrogen or C.sub.1-4 alkyl; said ring P being further optionally substituted; and --(Y).sub.n -- is a bond or various linking groups or --(Y)--.sub.n may be such so that rings Q and P are fused.The use of such compounds as antibacterial agents is described as are processes for their preparation and intermediates therefor.

Abstract: Cephalosporin compounds having a 3-position substituent of the formula (I) are described:--CH.sub.2 --S--Q--(Y).sub.n --Pwherein Q is a 5- or 6-membered heterocyclic ring, P is a benzene ring substituted by groups R.sup.1 and R.sup.2 which are ortho with respect to one another, wherein R.sup.1 is hydroxy or an in vivo hydrolysable ester thereof and R.sup.2 is hydroxy, an in vivo hydrolysable ester thereof, carboxy, sulpho, hydroxymethyl, methanesulphonamido or ureido; or P is a group of the formula (II) or (III): ##STR1## wherein M is oxygen or a group NR.sup.3 wherein R.sup.3 is hydrogen or C.sub.1-4 alkyl; said ring P being further optionally substituted; and --(Y).sub.n -- is a bond or various linking groups or --(Y)--.sub.n may be such so that rings Q and P are fused.The use of such compounds as antibacterial agents is described as are processes for their preparation and intermediates therefor.

Abstract: A process for the manufacture of a cephalosporin derivative of the formula I ##STR1## in which X is sulphur, oxygen or sulphinyl; R.sup.1 is any one of the C-3 substituents from antibacterially-active cephalosporins known in the art; R.sup.2 is hydrogen or 1-6C alkyl; R.sup.3 is hydrogen or 1-6C alkyl; and the pharmaceutically-acceptable acid-addition and base-addition salts thereof, characterized by cyclization of a compound of the formula II: ##STR2## or a derivative thereof in which the carbonyl group is masked, or an acid-addition salt thereof, in which R.sup.4 and R.sup.5 individually have one of the values for R.sup.2 and R.sup.3, R.sup.6 is a nitrogen-protecting group and R.sup.7 is hydrogen or any one of the cephalosporin 3-carboxylic acid protecting groups known in the art;whereafter when the product from the cyclization retains the protecting group R.sup.7 (when R.sup.7 is other than hydrogen) the protecting group R.sup.