反应详情

Phosphoryl chloride (19 ml) in dichloromethane (50 ml) was added dropwise to a stirred solution of 2-methyl-3-fluoro-4-nitropyridine-N-oxide (12 g) in dichloromethane (50 ml). The reaction mixture was heated under reflux for a total of 8 hours. After cooling and pouring onto ice, the mixture was basified (NaOH) to pH 9 and extracted with dichloromethane. After drying (K2CO3) and removal of solvent, the crude product was purified by column chromatography (silica gel; 1% MeOH/CHCl3) to give 2-methyl-3-fluoro-4-chloro-pyridine-N-oxide (6.78 g) m.p. 63°-65°.

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for a total of 8 hours
3. temperatureAfter cooling
4. additionpouring onto ice
5. extractionextracted with dichloromethane
6. customAfter drying
7. custom(K2CO3) and removal of solvent
8. customthe crude product was purified by column chromatography (silica gel; 1% MeOH/CHCl3)