反应详情

To a stirred solution of 2-chloro-4-methyl-3-nitropyridine (1.06 g, 6.14 mmol) in tetrahydrofuran (12 mL) under an atmosphere of nitrogen were added dibenzylamine (2.4 mL, 13 mmol) and sodium carbonate (684 mg, 6.45 mmol). The mixture was warmed to reflux for 48 h and cooled to room temperature. The mixture was diluted with dichloromethane (100 mL) and water (100 mL), and the layers were separated. The aqueous layer was extracted with dichloromethane (2×50 mL). The combined organic extracts were washed with 1 N HCl (100 mL) and brine (100 mL), dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by chromatography (silica gel, 10% ethyl acetate/hexanes) to provide 2-(dibenzylamino)-4-methyl-3-nitropyridine (1.53 g, 4.59 mmol, 75%) as a bright yellow oil which solidified upon standing. Rf 0.52 (67:33 hexanes/ethyl acetate); 1H NMR (300 MHz, CDCl3) δ2.32 (3H, s), 4.45 (4H, s), 6.70 (1H, d, J=4.9 Hz), 7.16-7.19 (4H, m), 7.21-7.34 (6H, m), 8.16 (1H, d, J=4.9 Hz); ESI MS m/z 334 [C20H19N3O2+H]+.

1. temperatureThe mixture was warmed
2. temperatureto reflux for 48 h
3. customthe layers were separated
4. extractionThe aqueous layer was extracted with dichloromethane (2×50 mL)
5. washThe combined organic extracts were washed with 1 N HCl (100 mL) and brine (100 mL)
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe residue was purified by chromatography (silica gel, 10% ethyl acetate/hexanes)