反应详情

温度

60 °C

100 g (0.352 mol) of diethyl 5-nitropyridine-2,3-dicarboxylate were added to 500 ml of phosphoryl chloride in the course of 15 minutes with stirring at 60° C., heated to reflux and stirred for 11/2 hours. After cooling, the reaction mixture was concentrated under reduced pressure and the residue dissolved again in methylene chloride. After stirring with ice-water, the aqueous phase was washed again with methylene chloride and the organic extracts were then washed in succession with water, saturated sodium hydrogencarbonate and sodium chloride solution and dried over magnesium sulfate. After filtering off with suction through neutral alumina and concentrating, 68.8 g (64.6% of theory) of the title compound of m.p. 70-72° C. were obtained.

1. temperatureheated
2. temperatureto reflux
3. stirringstirred for 11/2 hours
4. temperatureAfter cooling
5. concentrationthe reaction mixture was concentrated under reduced pressure
6. dissolutionthe residue dissolved again in methylene chloride
7. stirringAfter stirring with ice-water
8. washthe aqueous phase was washed again with methylene chloride
9. washthe organic extracts were then washed in succession with water, saturated sodium hydrogencarbonate and sodium chloride solution
10. dry with materialdried over magnesium sulfate
11. filtrationAfter filtering off with suction through neutral alumina
12. concentrationconcentrating