反应详情

温度

0 °C

To a mixture of concentrated H2SO4 (60 mL, 1126 mmol) and fuming HNO3 (40 mL, 895 mmol), ethyl (5-bromopyridin-3-yl)carbamate (21.5 g, 88 mmol) was added portionwise at 0° C. After stirring at 0° C. for 5 min, the mixture was stirred at rt overnight and poured onto ice water. A crash out formed and was filtered off and washed thoroughly with water and dried. Ethyl (5-bromo-2-nitropyridin-3-yl)carbamate (21.26 g, 84%) was thus obtained as a white solid. LCMS (m/z): 290.1 (MH+), 0.76 min. 1H NMR (400 MHz, CDCl3) δ ppm 9.63 (br. s., 1H) 9.33 (d, J=2.0 Hz, 1H) 8.28 (d, J=2.0 Hz, 1H) 4.32 (q, J=7.3 Hz, 3H) 1.68 (br. s., 2H) 1.38 (t, J=7.0 Hz, 4H).

1. additionwas added portionwise at 0° C
2. stirringthe mixture was stirred at rt overnight
3. additionpoured onto ice water
4. customA crash out formed
5. filtrationwas filtered off
6. washwashed thoroughly with water
7. customdried