反应详情

温度

0 °C

To a mixture of concentrated H2SO4 (3.0 mL) and fHNO3 (2.1 mL), 3-bromo-5-(ethoxycarbonyl)aminopyridine (Intermediate 9–20.0 g, 99.0 mmol) was portionwise added at 0° C. After stirring at 0° C. for 5 min., the mixture was stirred at room temperature overnight. The mixture was poured into ice-water then basified with aqueous NH4OH. The mixture was extracted with ethyl acetate. The organic layer was washed with aqueous NH4OH and brine, dried over Na2SO4 then evaporated. Sequence purification on SiO2 column chromatography gave 5-bromo-3-(ethoxycarbonyl)amino-2-nitropyridine (1.57 g, 54%).

1. additionwas portionwise added at 0° C
2. stirringthe mixture was stirred at room temperature overnight
3. extractionThe mixture was extracted with ethyl acetate
4. washThe organic layer was washed with aqueous NH4OH and brine
5. dry with materialdried over Na2SO4
6. customthen evaporated
7. customSequence purification on SiO2 column chromatography