反应详情

温度

60 °C

First, 510 mg of 6-(4-oxo-4H-pyridin-1-yl)-1,4-dihydroquinoxaline-2,3-dione was added to 5 ml of conc. sulfuric acid with ice-cooling and dissolved therein. Then, 253 mg of potassium nitrate was added to the resultant solution. The mixture was heated at 60° C. for 3 hours with stirring. Then, 20 ml of ice water was added to the mixture and the pH of the solution was adjusted to 5 with a solution of 4N sodium hydroxide. The precipitated yellow crystals were filtered. The crystals thus obtained were washed with water and dried to give 426 mg of 6-nitro-7-(4-oxo-4H-pyridin-1-yl)-1,4-dihydroquinoxaline-2,3-dione.

1. temperaturecooling
2. dissolutiondissolved
3. filtrationThe precipitated yellow crystals were filtered
4. customThe crystals thus obtained
5. washwere washed with water
6. customdried