反应详情

5.0 ml of boron tribromide are added dropwise over a period of approximately 5 minutes to a solution, cooled to 0°, of 2.70 g (10 mmole) of 2-[5-chloro-2-methoxy-4-(piperidin-1-yl)-phenyl]-ethanol in 70 ml of absolute methylene chloride. The reaction mixture is then stirred for a further 5 hours at room temperature, poured onto ice and the resulting suspension is adjusted to pH 6-7 with solid sodium carbonate and extracted with methylene chloride. The organic extracts are washed with water, combined, dried over sodium sulphate and concentrated in a vacuum rotary evaporator. Recrystallisation from petroleum ether yields 1-bromo-2-[5-chloro-2-hydroxy-4-(piperidin-1-yl)-phenyl]-ethane, melting point 115°-116°.

1. additionpoured onto ice
2. extractionextracted with methylene chloride
3. washThe organic extracts are washed with water
4. dry with materialdried over sodium sulphate
5. concentrationconcentrated in a vacuum rotary evaporator
6. customRecrystallisation from petroleum ether