Diisopropyl Ether → 7-[2-(2-Aminothiazol-4-yl)-2-(2,2,2-trichloroethoxycarbonylmethoxyimino)acetamido]-3-vinyl-3-cephem-4-carboxylic acid

Participants

Reaction Steps

A solution of benzhydryl 7-[2-(2-aminothiazol-4-yl)-2-(2,2,2-trichloroethoxycarbonylmethoxyimino)acetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer) (2.5 g) in trifluoroacetic acid (7.5 ml) and anisole (2.5 ml) was stirred at ambient temperature for 30 minutes. The reaction mixture was poured into diisopropyl ether, and the precipitates were collected by filtration, followed by dissolving them in a saturated aqueous sodium bicarbonate (50 ml). The aqueous solution was washed with ethyl acetate, adjusted to pH 2.0 with 10% hydrochloric acid and then extracted with ethyl acetate. The extract was washed with a saturated aqueous sodium chloride and then dried over magnesium sulfate. Removal of the solvent gave 7-[2-(2-aminothiazol-4-yl)-2-(2,2,2-trichloroethoxycarbonylmethoxyimino)acetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) (1.55 g).

Provenance & Evidence