Water → 5-Bromo-2-methanesulfonylpyridine

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Reaction Steps

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).

Provenance & Evidence