Beecham Group Plc

John P Clayton

Norman H Rogers

Kong Luk

Peter Hubert Bentley

George Burton

Harry Ferres

Andrew W Taylor

Martin Cole

Steven Coulton

Kenneth D Hardy

Angela W Guest

A synergistic combination is produced which comprises a synergistically effective amount of clavulanic acid or a pharmaceutically acceptable salt thereof and an antibacterially effective amount of a compound of the formula (II): ##STR1## or a pharmaceutically acceptable salt thereof wherein R.sup.1 is hydrogen, hydroxyl or acetoxyl, R.sup.2 is methyl and R.sup.3 is CO.R.sup.4 wherein R.sup.4 is phenyl, isobutyl, furyl, thienyl or NHCH.sub.3 or R.sup.2 is joined to R.sup.3 so that NR.sup.2 R.sup.3 is an imidazolin-2-on-1-yl.

Pharmaceutical compositions

Esters of an acid of formula: ##STR1## which is termed 'monic acid' have activity against Gram-positive and Gram-negative organisms.

Antibacterial compounds

6.beta.-[2-(2'-methylphenoxycarbonyl)-2-thien-3'-ylacetamido] penicillanic acid of formula (II): ##STR1## and pharmaceutically acceptable salts and in vivo hydrolyzable esters thereof, are active against Gram-positive and Gram-negative bacteria which makes them useful as therapeutic and prophylactic agents against bacterial infections in animals, including man and poultry. A process for the preparation and pharamceutical compositions comprising the penicillin, are also described.

Penicillins

7.alpha.-Methoxy-7.beta.-acylamino cephalosporins are prepared from 7.beta.-acylamino cephalosporins through formation of a ketenimine by the action of an acid halide, formation of an addition reaction adduct of this ketenimine, treatment of the adduct with a methoxide to form a 7.alpha.-methoxy ketenimine and hydrolysis of the latter ketenimine.

Chemical intermediates useful to prepare cephalosporins

Esters of monic and isomonic acids

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Horsham, United Kingdom

John P Clayton