Diazomethane → 2,2,2-Trichloroethyl 2-methyl-7-(2-methoxyimino-3-oxo-4-bromobutyramido)-3-cephem-4-carboxylate

Participants

Reaction Steps

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.).

Provenance & Evidence