Sughrue, Rothwell, Mion, Zinn and Macpeak
7-Methoxy cephalosporins
 A cephalosporin of the formula (I): ##STR1## wherein A is a mono- or polycyclic heteroaromatic ring containing at least one nitrogen atom as a hetero atom, which may be unsubstituted or substituted; R is a phenyl group which may be unsubstituted or substituted, a thienyl group, a furyl group, a cyclohexadienyl group or a cyclohexenyl group; X is an acetoxy group, a pyridinium group which may be unsubstituted or substituted with a methyl or carbamoyl group, a group of the formula: ##STR2## in which R.sub.1 and R.sub.2, which may be the same or different, each is a hydrogen atom or a (C.sub.1 -C.sub.4)alkyl group, or a group of the formula: EQU --S--Het in which Het is a heterocyclic ring containing 1 to 5 oxygen, nitrogen and sulfur atoms as a hetero atom, in which the heterocyclic ring system may be either polycyclic or 5- or 6-membered monocyclic and may be unsubstituted or substituted; and M is a hydrogen atom or a biologically active carboxyl-protecting group, or is an anionic charge only when X is a pyridinium group; and the pharamaceutically acceptable salts thereof, which are useful as antimicrobial agents and prepared by the reaction of a compound of the formula (II): EQU HO--A--COOH (II) wherein A is as defined above, or a reactive derivative thereof, with a compound of the formula (III): ##STR3## wherein R, M and X are as defined above, or a derivative thereof. 
Sumitomo Chemical Company, Limited
A C Y
A61P C07D Y02P
inventional inventional additional
Toshiaki Hirotada Takenari
Komatsu Yamada Nakagome