反应详情

温度

-10 °C

5-Phenyl-2-(1H)-pyrazinone (56 g) was added in portions over 30 minutes to a stirred mixture of concentrated sulphuric acid (35 ml) and fuming nitric acid (200 ml). The temperature of the nitrating mixture was initially at -20° C. and care was taken to ensure that the temperature did not rise above -15° C. When the pyrazinone had completely dissolved the reaction mixture was allowed to warm to -10° C., stirred for a further 30 minutes, and poured slowly on to ice/water (1500 ml). A pale yellow solid precipitated which was collected by filtration, washed with a small amount of cold water and dried to afford 5-(4-nitrophenyl)-2-(1H)-pyrazinone (58.1 g).

1. customwas initially at -20° C.
2. customdid not rise above -15° C
3. customA pale yellow solid precipitated which
4. filtrationwas collected by filtration
5. washwashed with a small amount of cold water
6. customdried