反应详情

To a solution of 2,2,2-trichloroethyl 2-methyl-7-(2-hydroxyimino-3-oxo-4-bromobutyramido)-3-cephem-4-carboxylate (a mixture of syn and anti isomers) (1.2 g.) in ethanol (20 ml.) was added dropwise a solution of diazomethane (0.1 mole) in diethyl ether under stirring and ice-cooling to complete the reaction. After the reaction mixture was concentrated under reduced pressure, the residue was pulverized in diisopropyl ether, collected by filtration and then dried to give brown powder of 2,2,2-trichloroethyl 2-methyl-7-(2-methoxyimino-3-oxo-4-bromobutyramido)-3-cephem-4-carboxylate (a mixture of syn and anti isomers) (1.1 g.), mp 80° to 83° C. (dec.).

1. temperatureice-cooling
2. customthe reaction
3. concentrationAfter the reaction mixture was concentrated under reduced pressure
4. filtrationcollected by filtration
5. customdried