反应详情

A mixture of triethylamine (13.12 mL; 90.73 mmol) in 1,1-dichloroethene (75 mL) was added to ethyl 2-chloro-2-(hydroxyimino)acetate (5.5 g; 36.29 mmol) in 1,1-dichloroethene (50 mL) over a period of 2 h the reaction mixture was stirred at room temperature for 20 min and portioned between water (75 mL) and dichloromethane (75 mL). The aqueous were extracted with dichloromethane, the organic layers rejoined were dried, concentrated under reduced pressure and the crude material was purified by flash chromatography on silica gel (eluent 2 to 20% ethyl acetate in heptane) to afford ethyl 5-chloroisoxazole-3-carboxylate 2.5 g (39%).

1. extractionThe aqueous were extracted with dichloromethane
2. customthe organic layers rejoined were dried
3. concentrationconcentrated under reduced pressure
4. customthe crude material was purified by flash chromatography on silica gel (eluent 2 to 20% ethyl acetate in heptane)