反应详情

12.2 g of sodium were dissolved 2 1 of methanol under argon, whereupon 60 g of 2,5-dimethyl-4-nitropyridine 1-oxide were added portionwise and the solution was left to boil under reflux overnight. The pH was adjusted to 7 with 5N hydrogen chloride in ethyl acetate while cooling and the mixture was evaporated in vacuo. The residue was taken up in 1 1 of methylene chloride, the solution was filtered through silica gel, which was rinsed with 0.4 1 of methylene chloride, and the combined filtrates were evaporated in vacuo The residue crystallized from methylene chloride/petroleum ether and there was obtained 4-methoxy-2,5-dimethylpyridine 1-oxide of melting point 99-101° .

1. waitthe solution was left
2. temperatureunder reflux overnight
3. temperaturewhile cooling
4. customthe mixture was evaporated in vacuo
5. filtrationthe solution was filtered through silica gel, which
6. washwas rinsed with 0.4 1 of methylene chloride
7. customthe combined filtrates were evaporated in vacuo The residue
8. customcrystallized from methylene chloride/petroleum ether