反应详情

To a solution of trifluoroacetic acid (20 ml) and anisole (10 ml) in methylene chloride (50 ml) was added benzhydryl 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-chloromethyl-3-cephem-4-carboxylate (syn isomer) (7.0 g) at 0°~-5° C. under stirring. The stirring was continued for 2 hours at the same temperature. The reaction mixture was poured into a cold mixture of diisopropyl ether (400 ml) and n-hexane (200 ml). The resulting precipitates were collected by filtration to give 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-chloromethyl-3-cephem-4-carboxylic acid (syn isomer) (5.5 g).

1. customThe resulting precipitates
2. filtrationwere collected by filtration