Trifluoroacetic acid → HCID 131712194, compound

Participants

Reaction Steps

Anisole (0.86 ml.) was added at ambient temperature to a solution of diphenylmethyl 7-[2-methoxyimino-2-(1,2,3-thiadiazol-4-yl)acetamido]-7-methoxy-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylate (syn isomer) (0.86 g.) in dry 1,2-dichloroethane (10 ml.), and then trifluoroacetic acid (1.68 g.) was added dropwise thereto under ice-cooling. The resulting mixture was stirred for 2 hours under ice-cooling and the reaction mixture was concentrated under reduced pressure. To the residue were added ethyl acetate (20 ml.) and water (20 ml.). After shaking the mixture, the ethyl acetate layer was separated. The remaining aqueous layer was further extracted with ethyl acetate (10 ml. and 5 ml.). The ethyl acetate layers were combined and 10% aqueous solution of dipotassium hydrogen phosphate (20 ml.) was added thereto. The mixture was shaken and the aqueous layer was separated. The ethyl acetate layer was further extracted with 10% aqueous solution of dipotassium hydrogen phosphate (10 ml. and 5 ml.). The aqueous layers were combined and washed in turn with ethyl acetate (10 ml. and 5 ml.) and ether (10 ml.). Two remaining solvent in the aqueous layer was removed by bubbling of nitrogen gas. The resulting aqueous layer was adjusted to pH 2 with 10% hydrochloric acid under ice-cooling. Precipitates were collected by filtration, washed with water and dried over phosphorus pentoxide under reduced pressure to give 7-[2-methoxyimino-2-(1,2,3-thiadiazol-4-yl)acetamido]-7-methoxy-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (0.21 g.).

Provenance & Evidence