Patent ID: 6420554
Filing Date: 2002-07-16
Classification: A61P,C07D

Abstract:
A process for preparing a 3-cephem compound represented by formula (3), the process comprising the steps of reacting a &bgr;-lactam compound represented by formula (1) with a phosphorus halide compound in the presence of an organic base to produce an imino-&bgr;-lactam compound represented by formula (2), adding a phenol to the same reaction system to cause decomposition due to reaction with an alcohol and simultaneously to remove the protection of carboxylic acid ester, producing a 3-cephem compound represented by formula (3) or a salt thereof wherein R1 is an arylmethyl group or an aryloxymethyl group, R2 is a) hydrogen atom, b) halogen atom, c) hydroxyl group, d) lower alkoxy group, e) lower alkyl group or a lower alkyl group substituted with halogen atom, f) lower alkoxyl, g) acetoxy, h) carbamoyloxy, i) lower alkenyl group or a lower alkenyl group substituted with halogen atom, j) lower alkynyl group, k) heterocyclic thiomethyl group selected from the group consisting of 1,2,3-triazol-4-ylthiomethyl, 5-methyl-1,3,4-thiadiazol-2-ylthiomethyl, 3-methyl-1,3,4-triazine-5,6-dione-2-thiomethyl, 1-methyltetrazol-5-ylthiomethyl, 1-sulfomethyltetrazol-5-ylthiomethyl, 1-carboxymethyltetrazol-5-ylthiomethyl, 1-(2-dimethylaminoethyl)tetrazol-5-ylthiomethyl, 1,3,4-thiadiazol-5-ylthiomethyl and 1-(2-hydroxyethyl)tetrazol-5-ylthiomethyl, or l) heterocyclic methyl group selected from the group consisting of methylpyrrolidinomethyl, pyridiniummethyl iodide, and 1,2,3-triazolemethyl, and R3 is a benzyl group which may have an electron-donating group as a substituent on a phenyl ring, or a diphenylmethyl group which may have an electron-donating group as a substituent on a phenyl ring, wherein the electron-donating group is selected from the group consisting of benzyl, p-methoxybenzyl, diphenylmethyl, 3,4,5-trimethoxybenzyl, 3,5-dimethoxy-4-hydroxybenzyl, 2,4,6-trimethylbenzyl, piperonyl, ditolymethyl, naphthylmethyl, and 9-anthryl, wherein R1, R2, and R3 are as defined above and X is a halogen atom wherein R2 is as defined above.