反应详情

Selenium dioxide (8.5 g, 76 mmol) is dissolved in a solution of dioxane (238 mL) and water (40 mL) at 55-60° C. To the solution of selenium dioxide, the compound of Example 9 (20 g, 51 mmol) is added and then the reaction mixture is heated at reflux for 10 hr. The reaction mixture is cooled to room temperature, diluted with ether (200 mL) and filtered. The filtrate is concentrated at reduced pressure on a rotary evaporator and then extracted with ethyl acetate (2×100 mL) to yield the crude title compound. MS m/z 406.9 (M+.+1).

1. temperaturethe reaction mixture is heated
2. temperatureat reflux for 10 hr
3. filtrationfiltered
4. concentrationThe filtrate is concentrated at reduced pressure on a rotary evaporator
5. extractionextracted with ethyl acetate (2×100 mL)