PENEM DERIVATIVES

摘要

This invention discloses new penem compounds, a process for their preparation, and pharmaceutical and veterinary compositions containing them. The compounds of the invention are penem derivatives of the following formula (I) wherein R is a C1-C3 alkyl group substituted by a free or protected hydroxy; Q(+) represents a group wherein R1 is a substituent selected from the group consisting of (a) halogen; (b) hydroxy; (c) C1-C4 alkoxy; (d) C1-C4 alkylthio; (e) a group wherein each of R4 and R5 is independently, hydrogen or C1-C4 alkyl; (f) sulfo; (g) -CO2R4 wherein R4 is as defined above (h) -C?N; (i) dimethylformimidino ¢ -N=CH-N(CH3)2 !; (j) a group wherein R4 and R5 are as defined above; (k) carbamoyloxy; (1) a hydroxyminomethyl (HO-N=CH-1) or methoxyminomethyl (CH3O-N=CH-) group; (m) a formamido or acetamido group; (n) a formyloxy or acetoxy group; (o) a C1-C4 alkanoyl group; (p) an aryl group; (q) a saturated or unsaturated heterocyclic ring; and (r) a C1-C4 alkyl group either unsubstituted or substituted by a substituent chosen from (a) to (q) above; each of R2 and R3 is, independently, hydrogen or one of the groups (a) to (r) defined above, provided that, when R2 and R3 are both hydrogen, then R1 is not a group wherein R4 and R5 are both hydrogen; and the pharmaceutically or veterinarily acceptable salts thereof. These compounds are prepared by a process reacting a compound of the formula (II): (II) wherein R1, R2 and R3 are defined hereinbefore, with either a compound of the formula (III) (III) wherein R is defined hereinbefore; Z' is a carboxy protecting group, and L is a leaving group susceptible of nucleophilic displacement by the reagent (II); or with a 2-thiacephem derivative of the formula (IV) (IV) wherein R and Z' are defined hereinbefore. These compounds have a high antibacterial activity and may be administered to humans or to animals.