反应详情

A solution of 2,5-dibromopyridine (1.0 g, 4.22 mmol) in DMF (15 mL) was treated with sodium thiomethoxide (0.69 g, 95%, 9.29 mmol) at ambient temperature. The reaction mixture was stirred for 30 minutes, was diluted water and then extracted with ether. The combined organic extract was washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to give crude sulfide as a colorless oil. The crude sulfide was dissolved in acetone (120 mL) and was treated with water (50 mL) followed by Oxone® (7.80 g, 12.7 mmol). The reaction mixture was stirred at ambient temperature for 2 h. After more water was added, the mixture was extracted with ether (200 mL) and EtOAc (150 mL). The organic layers were combined and washed with water and brine, dried over Na2SO4, filtered, and the filtrate was concentrated to give the crude product as a light brown oil. The crude product was purified by chromatography on ISCO silica gel column eluted with a 0 to 45% EtOAc:hexane gradient to give 0.54 g (54% from 2,5-dibromopyridine) of 5-bromo-2-(methylsulfonyl)pyridine as a white solid. 1H NMR (400 MHz, CDCl3): δ 8.78 (d, 1H, J=2.2 Hz), 8.10 (dd, 1H, Ja=8.3 Hz, Jb=2.2 Hz), 7.98 (d, 1H, J=8.3 Hz), 3.22 (s, 3H); LRMS (ESI), m/z 236/238 (M+H).

1. extractionextracted with ether
2. extractionThe combined organic extract
3. washwas washed with brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationthe filtrate was concentrated
7. customto give crude sulfide as a colorless oil
8. stirringThe reaction mixture was stirred at ambient temperature for 2 h
9. extractionthe mixture was extracted with ether (200 mL) and EtOAc (150 mL)
10. washwashed with water and brine
11. dry with materialdried over Na2SO4
12. filtrationfiltered
13. concentrationthe filtrate was concentrated
14. customto give the crude product as a light brown oil
15. customThe crude product was purified by chromatography on ISCO silica gel column
16. washeluted with a 0 to 45% EtOAc