| abstract |
A penicillin of formula (I) or a pharmaceutically acceptable salt-or in vivo hydrolysable ester thereof:n wherein R is C 1-6 alkyl; an optionally substituted 5-membered. heterocyclic ring containing one or two heteroatoms selected from oxygen, sulphur and nitrogen; phenyl; mono-substituted phenyl where the substituent is halogen, hydroxy, C 1-6 alkoxy, nitro amino, C 1-6 alkyl, or C 1-6 haloalkyl, C 1-6 alkylcarbonyloxy, or C 1-6 alkyl sulphonylamino; or di-substituted phenyl where the substituents are selected from hydroxy, halogen, methoxy, acetoxy and amino; and X represents a group of formula:n n wherein R 1 represents C 1 to C 6 alkyl, or C 1 to C 6 alkoxy. Their preparation and use is described. |