反应详情

To a solution of of 4-(5-fluoro-2-methoxy-phenyl)-4-hydroxypiperidine (0.56 g, 2.5 mmole) (Intermediate 8) in acetic acid (20 mL) at room temperature was added 2 drops of concentrated sulfuric acid and the resulting solution heated to reflux for 2 days. The reaction mixture was cooled to room temperature and diluted with EtOAc (50 mL) and water (50 mL). The solution was basified with 50% NaOH solution until PH=10, the layers separated and the organic layer was washed with brine (25 mL). The combined aqueous layers were extracted three times with EtOAc (3×25 mL), and the combined organic layers were dried over Na2SO4 and concentrated to afford 0.49 g (95% yield) of 4-(5-fluoro-2-methoxy-phenyl)-1,2,5,6-tetrahydropyridine as a yellow oil.

1. temperaturethe resulting solution heated
2. temperatureto reflux for 2 days
3. customthe layers separated
4. washthe organic layer was washed with brine (25 mL)
5. extractionThe combined aqueous layers were extracted three times with EtOAc (3×25 mL)
6. dry with materialthe combined organic layers were dried over Na2SO4
7. concentrationconcentrated