反应详情

A mixture of ethyl 2-hydroxyimino-3-oxo-4-chlorobutyrate (syn isomer, 10 g), ethylene glycol (16 g), p-toluenesulfonic acid (0.3 g) and dried benzene (100 ml) was heated for 19 hours under reflux while removing water azeotropically. After the reaction mixture was cooled to ambient temperature, water (30 ml) and benzene (20 ml) were added thereto. The mixture was saturated with sodium chloride and the benzene layer was separated, and the remaining aqueous layer was further extracted with benzene (20 ml). The benzene layer and extract were combined together, washed with a saturated aqueous solution of sodium chloride (30 ml×2), dried over magnesium sulfate and then filtered. The filtrate was evaporated to give an oil of ethyl 2-hydroxyimino-3,3-ethylenedioxy-4-chlorobutyrate (syn isomer, 7.23 g). (Yield: 58.9%).

1. temperaturewas heated for 19 hours
2. temperatureunder reflux
3. customwhile removing water azeotropically
4. additionwater (30 ml) and benzene (20 ml) were added
5. customthe benzene layer was separated
6. extractionthe remaining aqueous layer was further extracted with benzene (20 ml)
7. extractionThe benzene layer and extract
8. washwashed with a saturated aqueous solution of sodium chloride (30 ml×2)
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. customThe filtrate was evaporated