反应详情

A nitration mixture of 30% oleum (55 ml) and fuming nitric acid (90 ml) was added dropwise with cooling and stirring to a solution of 2-methyl-3-fluoropyridine-N-oxide (13.3 g) in concentrated sulphuric acid (48 ml) at 10°-15°. The solution was stirred at room temperature for 1.5 hours and then for 2 hours at 100°. 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-methyl-3-fluoro-4-nitropyridine-N-oxide (12.12 g) m.p. 170°-175°.

1. additionwas added dropwise
2. temperaturewith cooling
3. waitfor 2 hours at 100°
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