反应详情

To a solution of 2,2,2-trichloroethyl 2-methyl-7-[2-hydroxyimino-2-(2-aminothiazol-4-yl)acetamido]3-cephem-4-carboxylate (syn isomer), which can be represented as 2,2,2-trichloroethyl 2-methyl-7-[2-hydroxyimino-2-(2-imino-2,3-dihydrothiazol-4-yl)acetamido]-3-cephem-4-carboxylate (syn isomer), (125 mg.) in dioxane (5 ml.) was added dropwise 0.1 M solution of diazomethane in diethyl ether till the starting compound disappeared. After the reaction mixture was concentrated, the residue was pulverized in diethyl ether, collected by filtration and then dried to give brown powder of 2,2,2-trichloroethyl 2-methyl-7-[2-methoxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-cephem-4-carboxylate (syn isomer), which can be represented as 2,2,2-trichloroethyl 2-methyl-7-[2-methoxyimino-2-(2-imino-2,3-dihydrothiazol-4-yl)acetamido]-3-cephem-4-carboxylate (sym isomer), (110 mg.), mp 128° to 149° C. (dec.).

1. concentrationAfter the reaction mixture was concentrated
2. filtrationcollected by filtration
3. customdried