GB1472867A - Intermediates for cephalosporin synthesis - Google Patents

Abstract

1472867 Azetidinone - thiazoline intermediates for cephalosporin synthesis SOC FARMACEUTICI ITALIA SpA 11 Aug 1975 [15 Aug 1974] 21033/76 Divided out of 1472863 Heading C2C Novel azetidinone - thiazoline compounds of the formula wherein: R represents a hydrogen atom, an alkyl, cycloalkyl or alkenyl group that contains up to 12 carbon atoms and may be unsubstituted or substituted by one or more free or protected hydroxy or amino, cyano or nitro groups, a thienyl - methyl, furyl - methyl, naphthylmethyl, cyclohexenyl - methyl or cyclohexadienyl-methyl group, or a group having the general formula in which X is a hydrogen or halogen atom, a free or protected hydroxy group, an alkyl group having 1 to 4 carbon atoms or a nitro, cyano or protected amino group; Y is a protected hydroxy, amino or carboxyl group; n is 0 or an integer from 1 to 4; and each of the groups R<SP>2</SP>, which may be the same or different, is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R<SP>1</SP> represents a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a benzyloxy, p - methoxybenzyloxy, p - nitrobenzyloxy, benzhydryloxy, triphenylmethoxy, phenacyloxy, p - halophenacyloxy, or phthalimidomethoxy group, an amino group that is unsubstituted or substituted by at least one alkyl group having 1 to 4 carbon atoms, cycloalkyl group having 5 to 8 carbon atoms, phenyl group or mononuclear heterocyclic group, or an acyloxymethyloxy, acylamidomethyloxy, or free or protected hydrazino group; Hal represents a halogen atom, preferably chlorine or bromine; and Z represents a hydroxy, azido, amino, or carbamate group, an -O-alkyl, -OCO-alkyl or -S-alkyl group in which the alkyl residue contains 1 to 4 carbon atoms, an -S-aryl group, or an -S-mononuclear heretocyclic group containing one or more nitrogen and sulphur atoms, are prepared by allylic halogenation of a compound of the formula e.g. by means of a haloamide such as an N- halosuccinimide, and optionally in the presence of light or while heating in the presence of a free radical initiator. The compounds of the invention may be used in the synthesis of cephalosporin compounds as described in patent Specification 1,472,863.