反应详情

A nitration mixture of 30% oleum (24 ml) and fuming nitric acid (40 ml) was added dropwise with cooling to a solution of 2,3-dimethyl-5-fluoropyridine-N-oxide (6.64 g) in concentrated sulphuric acid (24 ml) at 10°-15°. The solution was stirred at room temperature for 1.5 hours and then 2 hours at 80°-90°. After cooling, the mixture was poured onto ice, basified (ammonium carbonate) and extracted with dichloromethane. After drying (K2CO3), the extracts were evaporated to dryness to give 2,3-dimethyl-4-nitro-5-fluoro-pyridine-N-oxide (5.88 g) m.p. 80°-83°.

1. additionwas added dropwise
2. custom2 hours
3. customat 80°-90°
4. temperatureAfter cooling
5. additionthe mixture was poured onto ice
6. extractionextracted with dichloromethane
7. dry with materialAfter drying (K2CO3)
8. customthe extracts were evaporated to dryness