反应详情

2-Chloro-3-methylpyridine 1-oxide (9.00 g, 62.7 mmol) and triethylamine (10.4 ml, 75.2 mmol) were dissolved in dichloromethane (70 ml), and a solution of phosphorus oxychloride (7 ml, 75.3 mmol) in dichloromethane (40 ml) was added dropwise at 0° C. After stirring for 3 hours while elevating reaction temperature to room temperature, the reaction mixture was stirred under reflux for 1 hour. After the reaction was completed, water (30 ml) was added and the reaction mixture was neutralized with a sodium hydroxide solution, and after extracted with dichloromethane (70 ml), dried over magnesium sulfate. The solvent was evaporated and purified by silica gel column chromatography (eluting solvent: ethyl acetate/n-hexane=3/100), thereby yielding the title compound (3.47 g) as a white solid 10:3 mixture with 2,4-dichloro-3-methylpyridine.

1. stirringthe reaction mixture was stirred
2. temperatureunder reflux for 1 hour
3. extractionafter extracted with dichloromethane (70 ml)
4. dry with materialdried over magnesium sulfate
5. customThe solvent was evaporated
6. custompurified by silica gel column chromatography (eluting solvent: ethyl acetate/n-hexane=3/100)