反应详情

温度

50 °C

Phosphorus oxychloride (18.4 g, 120 mmol) was added to dimethylformamide (8.8 g, 120 mmol), maintaining the temperature below 25° C. by an external ice-bath. Upon completion of the addition the reaction mixture was heated to 50° C. for 45 minutes and then cooled to room temperature. Chloroform (35 ml) was added and the resulting solution was brought to reflux. 3,4-Dichlorophenoxyacetaldehyde diethylacetal (9.61 g, 40.0 mmol) was added in portions. After heating for 3 hours at reflux the solution was cooled to room temperature and poured carefully onto a solution of potassium carbonate (115 g) in water (100 ml). The mixture was cooled in an ice-bath to around room temperature and extracted twice with dichloromethane. The combined organic layers were dried over sodium sulphate, filtered and evaporated in vacuo yielding a brown oil, which was purified by flash column chromatography (SiO2, ethyl acetate) yielding the title compound (5.38 g, 52% yield) as a brown solid.

1. temperaturemaintaining the temperature below 25° C. by an external ice-bath
2. additionUpon completion of the addition the reaction mixture
3. temperaturecooled to room temperature
4. temperatureto reflux
5. temperatureAfter heating for 3 hours
6. temperatureat reflux the solution
7. temperaturewas cooled to room temperature
8. temperatureThe mixture was cooled in an ice-bath to around room temperature
9. extractionextracted twice with dichloromethane
10. dry with materialThe combined organic layers were dried over sodium sulphate
11. filtrationfiltered
12. customevaporated in vacuo
13. customyielding a brown oil, which
14. customwas purified by flash column chromatography (SiO2, ethyl acetate)