反应详情

To a solution of 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-chloromethyl-3-cephem-4-carboxylic acid (syn isomer) (4.0 g) in N,N-dimethylformamide was added dropwise 1-methyl-4-tert-butoxycarbonylpiperazine (6.7 g) at 2° C. under stirring. The stirring was continued for 1.5 hours at 18°-2° C. The reaction mixture was poured into ethyl acetate (200 ml). The resulting precipitates were collected by filtration to give 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-(1-methyl-4-tert-butoxycarbonyl-1-piperazinio)methyl-3-cephem-4-carboxylate hydrochloride (syn isomer) (5.71 g) .

1. customThe resulting precipitates
2. filtrationwere collected by filtration