反应详情

To a solution of 3-hydroxypicolinamide (2.00 g, 14.5 mmol) in phosphorus oxychloride (10 mL) at room temperature was added phosphorus pentachloride (6.00 g, 28.8 mmol). The mixture was heated at reflux for 90 min, and the solvent was removed by distillation. The residue was poured into water, the aqueous solution was neutralized by addition of sodium bicarbonate, and was extracted with ethyl acetate. The organic phase was filtered through silica gel, the filtrate was concentrated, and the residue was subjected to flash chromatography on silica gel, affording 300 mg of 3-chloro-2-cyanopyridine. 1H NMR (CDCl3) δ 7.50 (dd, 1, J=4.8, 8.4), 7.89 (dd, 1, J=1.6, 8.4), 8.63 (dd, 1, J=1.6, 4.8).

1. temperatureThe mixture was heated
2. temperatureat reflux for 90 min
3. customthe solvent was removed by distillation
4. additionThe residue was poured into water
5. additionthe aqueous solution was neutralized by addition of sodium bicarbonate
6. extractionwas extracted with ethyl acetate
7. filtrationThe organic phase was filtered through silica gel
8. concentrationthe filtrate was concentrated