反应详情

A solution of phosphorus tribromide (5 g) in carbon tetrachloride (10 ml) was added, dropwise, to a solution of 4-cyanophenethyl alcohol (8.06 g) in carbon tetrachloride (60 ml). The mixture was heated under reflux for 4 hours. On cooling to room temperature, the mixture was poured onto ice (200 g). The layers were separated and the organic layer was washed with 10% aqueous sodium carbonate (50 ml) and brine (50 ml), dried (MgSO4) and concentrated in vacuo to give a colourless oil which solidified on standing. The solid was chromatographed on silica eluting with ethyl acetate containing hexane (20%). The fractions containing the less polar (higher Rf) product were combined and concentrated in vacuo to give 4-cyanophenethyl bromide as a yellow oil which solidified on standing, yield 8.9 g. The fractions containing the more polar (lower Rf) product were combined and concentrated in vacuo to give the title compound as a colourless solid, yield 0.47 g, m.p. 152°-153° .

1. temperatureThe mixture was heated
2. temperatureunder reflux for 4 hours
3. additionthe mixture was poured onto ice (200 g)
4. customThe layers were separated
5. washthe organic layer was washed with 10% aqueous sodium carbonate (50 ml) and brine (50 ml)
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo
8. customto give a colourless oil which
9. customThe solid was chromatographed on silica eluting with ethyl acetate
10. additioncontaining hexane (20%)
11. additionThe fractions containing the less polar (higher Rf) product
12. concentrationconcentrated in vacuo