Ethyl chloroformate → HCID 131711444, compound

Participants

Reaction Steps

Ethyl chloroformate (10.9 g.) was dropwise added by small portions with stirring and ice-cooling to a solution of sodium 7-[2-hydroxyimino-2-(3-hydroxyphenyl)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylate (syn isomer) (16.3 g.) in a mixture of water (80 ml.) and pyridine (80 ml.), and the mixture was stirred for 1 hour at the same temperature. Water (200 ml.) was added thereto and the mixture was washed with ether. The aqueous layer was adjusted to pH 2 with hydrochloric acid and extracted with ethyl acetate. The extract was washed with dilute hydrochloric acid and with a sodium chloride aqueous solution and dried over magnesium sulfate. After treating with activated charcoal, the solvent was distilled off and the residual oil was pulverized with a mixture of diisopropyl ether and ether. The powder was collected by filtration, dried and suspended in water (150 ml.). To the suspension was added sodium bicarbonate (1.7 g.). The solution was adjusted to pH 6 with dilute hydrochloric acid and treated with activated charcoal. Dilute hydrochloric acid was added thereto with cooling and stirring and precipitates were collected by filtration, washed with water and dried to give 7-[2-ethoxycarbonyloxyimino-2-(3-hydroxyphenyl)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (9.4 g.).

Provenance & Evidence