反应详情

Phosphorus tribromide (0.37 g) was added to a solution of 5-(2-hydroxyethyl)-2,3-dihydrobenzofuran (0.612 g--see Preparation 16) in carbon tetrachloride (3 ml) and the mixture was heated under reflux for 3 hours. On cooling to room temperature, the mixture was partitioned between 10% aqueous sodium carbonate (20 ml) and dichloromethane (20 ml). The layers were separated and the aqueous layer was extracted with dichloromethane (2×10 ml). The combined dichloromethane extracts were dried (MgSO4) and concentrated in vacuo to give the title compound as an oil which crystallised on standing, yield 0.584 g, m.p. 60°-62° C.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 3 hours
3. customthe mixture was partitioned between 10% aqueous sodium carbonate (20 ml) and dichloromethane (20 ml)
4. customThe layers were separated
5. extractionthe aqueous layer was extracted with dichloromethane (2×10 ml)
6. dry with materialThe combined dichloromethane extracts were dried (MgSO4)
7. concentrationconcentrated in vacuo