反应详情

A solution of 2-chloro-3-methylpyridine 1-oxide (11.37 g, 79.2 mmol) and triethylamine (13.1 ml, 94.0 mmol) in dichloromethane (90 mL) at 0° C. was slowly treated with a solution of phosphorus oxychloride (8.8 ml, 96.1 mmol) in dichloromethane (35 mL) and stirred for a further 2 hours then heated to reflux for 1 hour. Water (40 mL) was added to the reaction mixture then it was basified with 2N sodium hydroxide (150 mL). The mixture was extracted with dichloromethane (3×100 mL) and the combined extracts were dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The product was purified by flash column chromatography on silica gel (160 g) 100% dichloromethane to afford 2,6-dichloro-3-methylpyridine as a white solid (2.64 g, 21%). 400 M Hz 1H NMR (DMSO-d6) δ: 7.86 (d, J=8.4 Hz, 1H), 7.47 (d, J=8.0 Hz, 1H), 2.30 (s, 3H).

1. temperaturethen heated
2. temperatureto reflux for 1 hour
3. extractionThe mixture was extracted with dichloromethane (3×100 mL)
4. dry with materialthe combined extracts were dried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe product was purified by flash column chromatography on silica gel (160 g) 100% dichloromethane