反应详情

To a solution of 2-bromo-3-methoxy-6-nitropyridine (2.0 g, 8.6 mmol) in ethanol (20 mL) was added SnCl2.2H2O (3.9 g, 17 mmol) at room temperature. The reaction was heated at reflux for 2H. After cooling to room temperature, the reaction mixture was poured into water (50 mL), basified to pH to 8 with saturated NaHCO3 and extracted with ethyl acetate (50×3 mL). The combined organic layers were dried over Na2SO4, evaporated in vacuo and purified by chromatography on silica gel (20% ethyl acetate in petroleum ether) to afford 6-bromo-5-methoxypyridin-2-amine (1.1 g, 65%). 1H-NMR (300 MHz, CDCl3) δ 7.09 (d, J=8.4, 1H), 6.43 (d, J=8.4, 1H), 4.27 (br s, 2H), 3.82 (s, 3H).

1. temperatureThe reaction was heated
2. temperatureat reflux for 2H
3. extractionextracted with ethyl acetate (50×3 mL)
4. dry with materialThe combined organic layers were dried over Na2SO4
5. customevaporated in vacuo
6. custompurified by chromatography on silica gel (20% ethyl acetate in petroleum ether)