Abstract: Compounds of formula (I): ##STR1## (wherein A is an alkylene group substituted by an optionally substituted amino or heterocyclic group and optionally interrupted by an oxygen or sulfur atom, R.sup.2 is various organic groups, B is C.sub.1 -C.sub.2 alkylene and Y is sulfur or methylene) and pharmaceutically acceptable salts and esters thereof are valuable hypotensive agents which may be prepared by a condensation reaction of the corresponding compound having an amino group in place of the group A--CH(COOH)--NH--.

Abstract: Compounds of formula (I): ##STR1## (wherein R.sup.1 and R.sup.3 are organic groups, A is a direct bond, --CH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CO--CH.sub.2, --O--CH.sub.2 -- or --S--CH.sub.2 --, B is lower alkylene and n is 1-3) are valuable hypotensive agents which may be prepared by a condensation reaction of the corresponding compound having an amino group at the 3-position.

Abstract: Compounds of formula (I): ##STR1## (wherein: R.sup.1 represents an optionally substituted alkyl, cycloalkyl, aryl, partially hydrogenated aryl or heterocyclic group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 represent hydrogen or an optionally substituted alkyl, cycloalkyl, aralkyl, aryl, heterocyclic or heterocyclic-alkyl group or any adjacent pair thereof form a cyclic structure, at least one not being hydrogen; A represents a bond, or a methylene, ethylene, oxymethyl or thiomethyl group; B represents an alkylene, alkylidene, cycloalkylene or cycloalkylidene group; and n is 0, 1 or 2) and salts and esters thereof are hypotensive agents.

Abstract: 7.alpha.-Methoxycephalosporin derivatives of general formula (I): ##STR1## wherein: R.sup.1 represents a hydroxy group; a C.sub.1 -C.sub.4 alkoxy group; a C.sub.2 -C.sub.5 aliphatic acyloxy group; a benzoyloxy group which is unsubstituted or has one or more C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, nitro or halogen substituents; a benzenesulphonyloxy group which is unsubstituted or has one or more C.sub.1 -C.sub.4 alkyl substituents; or a C.sub.1 -C.sub.3 alkanesulphonyloxy group which is unsubstituted or has one or more C.sub.1 -C.sub.3 alkoxy, cyano, nitro, halogen or C.sub.2 -C.sub.4 alkoxycarbonyl substituents;R.sup.2 represents a hydrogen atom, a C.sub.1 -C.sub.4 alkyl group, a halogen atom, a carboxyl group, a C.sub.2 -C.sub.5 alkoxycarbonyl group, a carbamoyl group, an alkylcarbamoyl group in which the alkyl moiety has from 1 to 3 carbon atoms, a di(C.sub.1 -C.sub.3 alkyl)carbamoyl group or a cyano group;R.sup.

Abstract: Process for preparing .beta.-lactam antibiotic substances useful as intermediate for various cephalosporin or penicillin derivatives, which comprises oxidation of 7-benzylideneaminocephem or 6-benzylideneaminopenam compounds capable of being converted to their quinoid forms by oxidation followed by reaction with lower alkanols.

Abstract: Process for preparing 7-alkoxy cephalosporins useful as intermediates for various cephalosporin or penicillin derivatives which comprises reacting 7-benzylideneaminocephem or 6-benzylideneaminopenam compounds with a halide cation-producing compound in the presence of an alcohol and a base capable of forming a salt with a phenolic hydroxyl group or converting a phenolic hydroxyl group to phenolate ion.

Abstract: A process for introducing an alkoxy group into the 7.alpha.-position of a 7-amino-3-cephem-4-carboxylic acid derivative which comprises oxidizing a salt of 7-benzylideneamino-3-cephem-4-carboxylic acid derivative and reacting the product with an alkanol.The 7.alpha.-alkoxy-3-cephem-4-carboxylic acid derivatives obtained by the present invention are useful as intermediates for the synthesis of antibacterial agents.

Abstract: Process for preparing .beta.-lactam antibiotic substances useful as intermediate for various cephalosporin or penicillin derivatives, which comprises oxidation of 7-benzylideneaminocephem or 6-benzylideneaminopenam compounds capable of being converted to their quinoid forms by oxidation followed by reaction with lower alkanols.