Trifluoroacetic acid → HCID 131713338, compound

Participants

Reaction Steps

Trifluoroacetic acid (9.6 ml) was added to a solution of benzhydryl 7-[2-(1-tert-butoxycarbonylethoxyimino)-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer) (2.4 g) in methylene chloride (5 ml) and anisole (2.4 ml) under ice-cooling, and the mixture was stirred for 1 hour at room temperature. The resultant solution was added dropwise to diisopropyl ether (100 ml) and the precipitates were collected by filtration. The precipitates were added to a mixture of water and ethyl acetate and then adjusted to pH 7.5 with 10% aqueous sodium hydroxide. The separated aqueous layer was saturated with sodium chloride and adjusted to pH 1.5 with 10% hydrochloric acid, followed by extraction with a mixed solvent of ethyl acetate and tetrahydrofuran (1:1 by volume). The extract was washed with a saturated aqueous sodium chloride and dried over magnesium sulfate. Removal of the solvent gave 7-[2-(1-carboxyethoxyimino)-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) (0.55 g).

Provenance & Evidence