反应详情

2-Bromopyridine-N-oxide (28.36 g) was carefully dissolved in concentrated sulphuric acid (43 ml) with stirring. A mixture of concentrated sulphuric acid (65 ml) and concentrated nitric acid (43 ml) was added dropwise, and the mixture refluxed for 3 hours and allowed to cool to room temperature. The mixture was then poured on to ice and the precipitate removed by filtration , washed with water and air dried leaving a fine yellow powder of 2-Bromo-4-nitro-pyridine-N-oxide (14.08 g, 63%), m.p. 145-147° C.

1. additionwas added dropwise
2. temperaturethe mixture refluxed for 3 hours
3. additionThe mixture was then poured on to ice
4. customthe precipitate removed by filtration
5. washwashed with water and air
6. customdried