Beecham Group Plc

Gerald Brooks

Nigel J Broom

Peter Hubert Bentley

Brian P Clarke

Steven Coulton

John S Davies

Compounds of the general formula (II): ##STR1## in which N.sup.+ denotes an unsubstituted or substituted nitrogen-containing heterocyclyl ring bonded to the remainder of the molecule through a ring nitrogen atom and carrying a positive charge on said nitrogen atom;

Penem compounds

Compounds of the general formula (II): ##STR1## and pharmaceutically acceptable salts and in-vivo hydrolysable esters thereof, in which

The compounds of the formula (I): ##STR1## and pharmaceutically acceptable salts and in-vivo hydrolysable esters thereof wherein X is a sulphur atom or SO or SO.sub.2 group and R is a hydrogen atom or an alkyl group of 1 to 6 carbon atoms have been found to be .beta.-lactamase inhibitors and antibacterial agents. Their preparation and use is described.

Clavulanic acid derivatives their preparation and use

The use of an iodolactone as an esterifying derivative in the preparation of lactonyl esters of cephalosporins substantially reduces double bond migration during the esterification reaction.

Growing community of inventors

Betchworth, United Kingdom

Gerald Brooks