PROCESS FOR THE PREPARATION OF SYN-ISOMER OF 2-(2-AMINOTHIAZOL-4-YL)-2-METHOXYIMINO ACETYL CHLORIDE HYDROCHLORIDE

摘要

A process for the preparation of syn-isomer of 2-(2-aminothiazol-4-yl)-2-methoxyimino acetyl chloride hydrochloride containing up to 5 wt.% of the anti-isomer of formula (III) by reacting the anhydrous acid hydrochloride salt of the syn-isomer of 2-(2-aminothiazol-4-yl)-2-methoxyimino acetic acid with a mixture containing at least one molar equivalent of oxalyl chloride and at least one molar equivalent to a slight excess of dimethylformamide to an amount of said oxalyl chloride in an inert organic solvent at a temperature of less than -10 DEG C. The compound is a useful intermediate for preparing broad spectrum antibacterial agents, cefepime dihydrochloride hydrate which is also known as 7-[2-(2- -aminothiazol-4-yl)-2-(Z)-methoxyiminoacetamido]-3-[(1- -methyl-1-pyrrolidinio)-methyl]ceph-3-em-4-carboxylate.