反应详情

A solution of 2-hydroxy-5-nitronicotinic acid (9.2 g, 0.05 mol) in phosphorus oxychloride (25 ml) was refluxed for 5 hours. The solvent was removed in vacuo and the residue dissolved in a mixture of tetrahydrofuran and ether. After cooling the solution in an ice bath, water was cautiously added dropwise with stirring until a clean separation of layers was obtained. The organic layer was washed with water and a saturated sodium chloride solution, dried (anhydrous magnesium sulfate) and concentrated. Recrystallization from ether gave 6.94 g (69% of theory) of pure product, m.p. 135° C. (dec).

1. customThe solvent was removed in vacuo
2. dissolutionthe residue dissolved in a mixture of tetrahydrofuran and ether
3. temperatureAfter cooling the solution in an ice bath
4. additionwater was cautiously added dropwise
5. customwas obtained
6. washThe organic layer was washed with water
7. dry with materiala saturated sodium chloride solution, dried (anhydrous magnesium sulfate)
8. concentrationconcentrated
9. customRecrystallization from ether
10. customgave 6.94 g (69% of theory) of pure product, m.p. 135° C. (dec)