Cephem-carboxylic acid deriv.

摘要

3-Acetoxymethyl 7-(2-(2-aminothiazol-4-yl) 2-synmethoxyimino) acetamido 3-cephem 4-carboxylic acid of formula (I) is made by (a) reacting TTMA with PCl5 in dichloromethane at 0-5 deg.C to give (II); (b) condensing this with 7-ACA in an inert solvent e.g. dichloromethane, in presence of a tert. amine e.g. triethylamine at 0-25 deg.C to obtain 7-((2-(2-trityl aninoazoly-4-yl)2 -syn-methoxyimino)acetamido 3-acetoxy methyl 3-cephem 4-carboxylic acid; and (c) hydrolysing this to obtain (I) and its sodium salt. TTMA is 2-(2-trilaminothiazol-4-yl) 2-syn-methoxyimino acetic acid and 7-ACA is 7-amino cephalosporanic acid.