反应详情

Sodium hydroxide (40 mg, 1 mmol) was added to a solution of 5-hydroxybenzofurazan (136 mg, 1 mmol) in ethanol (2 ml) and the mixture was stirred at room temperature for 30 min. 1,2-dibromoethane (0.26 ml, 0.56 g, 3 mmol) was added and the mixture was heated under reflux for 20 hr., cooled and the solvent was evaporated under reduced pressure. Aqueous sodium bicarbonate (saturated, 10 ml) was added and the mixture was extracted with dichloromethane (3×10 ml). The combined organic fractions were dried (Na2SO4) and evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with hexane/10% EtOAc to give the benzofurazan as a pale yellow oil (99 mg, 41%).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 20 hr
3. temperature, cooled
4. customthe solvent was evaporated under reduced pressure
5. additionAqueous sodium bicarbonate (saturated, 10 ml) was added
6. extractionthe mixture was extracted with dichloromethane (3×10 ml)
7. dry with materialThe combined organic fractions were dried (Na2SO4)
8. customevaporated under reduced pressure
9. customThe residue was purified by flash column chromatography on silica gel
10. washeluting with hexane/10% EtOAc