Trifluoroacetic acid → 7-[2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido]-3-[2-(3-pyridyl)vinyl]-3-cephem-4-carboxylic acid

Participants

Reaction Steps

Trifluoroacetic acid (1.2 ml) was added to a suspension of benzhydryl 7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido]-3-[2-(3-pyridyl)vinyl]-3-cephem-4-carboxylate (syn isomer)(cis-trans mixture)(1.0 g) in dichloromethane (10 ml) and anisole (0.65 ml) at ambient temperature and stirred for 2 hours at the same temperature. To the resulting solution was added isopropyl ether (50 ml) and stirred. The precipitates, collected by filtration, were washed with diisopropyl ether. The precipitates were added to a mixture of ethyl acetate and water and adjusted to pH 7.5 with 20% aqueous potassium carbonate. The separated aqueous layer was adjusted to pH 3.5 with 10% hydrochloric acid under ice-cooling. The resulting precipitates were filtered off, washed with ice water and dried over phosphorus pentoxide in vacuo to give 7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido]-3-[2-(3-pyridyl)vinyl]-3-cephem-4-carboxylic acid (syn isomer)(cis-trans mixture)(0.4 g).

Provenance & Evidence