反应详情

温度

10 °C

A solution of sodium nitrite (12.4 g.) in water (150 ml.) was dropwise added with stirring at 5° to 7° C. to a solution of ethyl 4-bromoacetoacetate (30 g.) in acetic acid (200 ml.) and the mixture was stirred for 2 hours at 10° C. Water (200 ml.) was added to the reaction mixture and the resultant mixture was extracted with ether (500 ml.). The extract was washed twice with water (200 ml.) and with a sodium chloride aqueous solution (200 ml.) and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to give yellowish brown crystals of ethyl 2-hydroxyimino-4-bromoacetoacetate (a mixture of syn and anti isomers) (32.6 g.).

1. extractionthe resultant mixture was extracted with ether (500 ml.)
2. washThe extract was washed twice with water (200 ml.) and with a sodium chloride aqueous solution (200 ml.)
3. dry with materialdried over magnesium sulfate
4. distillationThe solvent was distilled off under reduced pressure