Trifluoroacetic acid → 7-[2-(2-Aminothiazol-4-yl)-2-carboxymethoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid

Participants

Reaction Steps

To a suspension of benzhydryl 7-[2-(2-aminothiazol-4-yl)-2-tert-butoxycarbonylmethoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer) (15.0 g) in anisole (15 ml) was added 2,2,2-trifluoroacetic acid (60 ml) under ice-cooling with stirring, and the stirring was continued at 10° to 15° C. for 80 minutes. After the reaction mixture was poured into diisopropyl ether (600 ml), the insoluble substance was collected by filtration and then dried. This substance (11.2 g) was dissolved in an aqueous solution to sodium bicarbonate so as to adjust the resultant solution to pH 6.0, and then chromatographed on alumina (44.8 ml) using 5% aqueous sodium acetate as an eluent. The fractions containing the desired compound were collected and evaporated to dryness to give 7-[2-(2-aminothiazol-4-yl)-2-carboxymethoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) (3.55 g), mp>250° C.

Provenance & Evidence