反应详情

To a solution of 2,2,2-trichloroethyl 2-methyl-7-(3-oxo-4-bromobutyramido)-3-cephem-4-carboxylate (2.54 g.) in glacial acetic acid (25 ml.) was added dropwise a solution of sodium nitrite hydrate (0.33 g.) in water (1 ml.) over 3 minutes with stirring at 10° to 15° C., and then the mixture was stirred for 1 hour at the same temperature. After the reaction mixture was poured into cold water (70 ml.), the precipitates were collected by filtration and then dried to give brown powder 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) (2.0 g.), mp 76° to 80° C. (dec.).

1. stirringthe mixture was stirred for 1 hour at the same temperature
2. filtrationthe precipitates were collected by filtration
3. customdried