反应详情

To a suspension of 2-hydroxy-4-methyl-5-nitropyridine (1 g, 6.5 mmol) in dichloroethane (10 mL) was added a solution of phosphorus oxybromide (2.8 g, 9.7 mmol) in dichloroethane (10 mL). The reaction mixture was heated under reflux for 4 h, then cooled to rt and quenched with water (40 mL). The layers were separated and the aqueous layer extracted into dichloromethane (2×30 mL). The combined organics were dried (MgSO4), concentrated in vacuo and chromatographed on silica gel eluting with dichloromethane to give the title compound as a pale yellow solid. δH (CDCl3): 2.63 (3H, s), 7.52 (1H, s), 8.96 (1H, s).

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for 4 h
3. customquenched with water (40 mL)
4. customThe layers were separated
5. extractionthe aqueous layer extracted into dichloromethane (2×30 mL)
6. dry with materialThe combined organics were dried (MgSO4)
7. concentrationconcentrated in vacuo
8. customchromatographed on silica gel eluting with dichloromethane