反应详情

To a solution of methyl 6-bromo-5-chloropyridin-2-ylcarbamate (1.1 g, 4.1 mmol) in methanol (50 mL) was added KOH (700 mg, 13 mmol) at room temperature. The mixture was heated at reflux for 2 hr. The reaction mixture was diluted with water and extracted with ethyl acetate (20 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under vacuum. The residue was purified by column chromatography on silica gel (5% to 10% EtOAc in petroleum ether) to give 6-bromo-5-chloropyridin-2-amine (700 mg, 81%). 1H NMR (400 MHz, CDCl3) δ 7.54 (d, J=8.0 Hz, 1H), 6.41 (d, J=8.4 Hz, 1H).

1. temperatureThe mixture was heated
2. temperatureat reflux for 2 hr
3. extractionextracted with ethyl acetate (20 mL×3)
4. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
5. customevaporated under vacuum
6. customThe residue was purified by column chromatography on silica gel (5% to 10% EtOAc in petroleum ether)