Methanesulfonyl chloride → 2-Bromo-5-(methylsulfonyl)pyridine

Temperature

0 °C

To a solution of 2,5-dibromopyridine (5 g, 21.1 mmol) in THF (20 mL) at 0° C. was slowly added 2M isopropylmagnesium chloride in THF (14.4 ml). The mixture was stirred at 0° C. for 1 hour, cooled to −15° C. followed by the dropwise addition of methane sulfonyl chloride in 5 mL THF. The mixture was slowly warmed up to room temperature, diluted with water (5 mL) and t-butylmethyl ether (3×50 mL). The layers were separated and the aqueous layer extracted with t-butylmethyl ether (2×). The combined organic layers were washed with brine, dried MgSO4, filtered and concentrated under reduced pressure and purified by chromatography (silica gel, eluting with 30% hexane-70% ethyl acetate) to provide the titled compound. MS (CI) m/z 237 (M+1)+, 254 (M+NH4)+ 1H NMR (300 MHz, CDCl3) δ ppm: 8.92 (d, 1H), 8.06 (dd, 1H), 7.73 (d, 1H), 3.12 (s, 1H).

1. customat 0° C.
2. temperaturecooled to −15° C.
3. temperatureThe mixture was slowly warmed up to room temperature
4. customThe layers were separated
5. extractionthe aqueous layer extracted with t-butylmethyl ether (2×)
6. washThe combined organic layers were washed with brine, dried MgSO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. custompurified by chromatography (silica gel, eluting with 30% hexane-70% ethyl acetate)

ORD record

ord-5b592ededc444b48a6e63f3dc77c72f2

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08637546B2