β-Lactam antibiotics are disclosed having the partial structure:
where R1 is:
in which R2, R3 and R4 are the same or different and each is hydrogen; halogen; optionally substituted C1-6 alkyl; optionally substituted C3-7 cycloalkyl; optionally substituted C2-6 alkenyl; optionally substituted C2-6 alkynyl; amido; cyano; carboxy; formyl; C1-6 alkoxycarbonyl; mono- or
di-(C1-6)alkylamido; C1-6 alkylcarbonyl; an aryl group; a heterocyclyl group; or R3 and R4 are joined together to form the residue of a carbocyclic ring having a total of from 3 to 7 carbon atoms in the ring; or R3 and R4 are joined together to form the residue of a heterocyclic ring in which R3 and R4 together may be represented by the formula -(CH2)mX(CN2)n in which X is oxygen, sulphur or a group NR5 wherein R5 is hydrogen, acyl, an amino-protecting group, or C1-6 alkyl, m is 1 to 3 and n is 1 to 3; and also the use thereof.
Processes for the preparation of the compounds are disclosed together with intermediates for use therein.