反应详情

To a solution of ethyl 2-methoxyimino-3-oxobutyrate (syn isomer, 200 g) in ethylene glycol (179 g) were added dried benzene (3 l) and p-toluenesulfonic acid (6 g), and the mixture was heated for 20 hours under reflux while removing water azeotropically. The reaction mixture was cooled to ambient temperature, washed with water, a saturated aqueous solution of sodium bicarbonade, water and a saturated aqueous solution of sodium chloride in turn, dried over magnesium sulfate and then filtered. After the filtrate was evaporated, the residual oil was distilled under reduced pressure to give ethyl 2-methoxyimino-3,3-ethylenedioxybutyrate (syn isomer), bp 89.5°-91° C./0.6 mmHg, in 85.5% yield.

1. temperaturethe mixture was heated for 20 hours
2. temperatureunder reflux
3. customwhile removing water azeotropically
4. washwashed with water
5. dry with materiala saturated aqueous solution of sodium bicarbonade, water and a saturated aqueous solution of sodium chloride in turn, dried over magnesium sulfate
6. filtrationfiltered
7. customAfter the filtrate was evaporated
8. distillationthe residual oil was distilled under reduced pressure