反应详情

温度

70 °C

In a round-bottomed flask, phosphorous oxybromide (5.0 g, 17.4 mmol and 4-tert-butylpyridine N-oxide (0.85 g, 5.34 mmol) were dissolved in 1,2-dichloroethane (35 mL). The reaction mixture was stirred at 70° C. overnight then cooled to room temperature and slowly poured onto ice. Sodium hydroxide (50% solution in water) was added slowly until pH˜10. The mixture was then extracted three times with ˜100 mL dichloromethane. The organic layers were combined, dried over sodium sulfate, filtered and concentrated. The residue was absorbed on 4 g SiO2 and chromatographed over 24 g SiO2 with EtOAc/Hexanes (gradient: 0-10% EtOAc). All fractions containing product were combined and concentrated to give 157 mg (14%) of 2-bromo-4-tert-butyl pyridine as a colorless oil.

1. temperaturethen cooled to room temperature
2. additionslowly poured onto ice
3. extractionThe mixture was then extracted three times with ˜100 mL dichloromethane
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was absorbed on 4 g SiO2
8. customchromatographed over 24 g SiO2 with EtOAc/Hexanes (gradient: 0-10% EtOAc)
9. additionAll fractions containing product
10. concentrationconcentrated