反应详情

温度

4 °C

To a stirred solution of c.H2SO4 (740 mL) at 0 to 5° C. was added 1,3-dibromo-5-fluoro-2-methoxybenzene (223.3 g, 0.786 mol). A solution of fuming nitric acid (90%, 38 mL, 0.815 mol) in c.H2SO4 (740 mL) was added dropwise, maintaining the temperature between 0 and 5° C. The reaction mixture was stirred at 3 to 5° C. for 2 hours, quenched into ice (2.2 kg) and extracted with dichloromethane (3×2 L). The combined dichloromethane extracts were washed with saturated aqueous NaHCO3 solution (2×2 L), dried over Na2SO4, filtered and the filter cake washed with DCM (3×400 mL). The filtrate was concentrated in vacuo at 40° C. to give 1,3-Dibromo-5-fluoro-2-methoxy-4-nitrobenzene as a pale orange crystalline solid (244.9 g, 95%).

1. temperaturemaintaining the temperature between 0 and 5° C
2. customquenched into ice (2.2 kg)
3. extractionextracted with dichloromethane (3×2 L)
4. washThe combined dichloromethane extracts were washed with saturated aqueous NaHCO3 solution (2×2 L)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. washthe filter cake washed with DCM (3×400 mL)
8. concentrationThe filtrate was concentrated in vacuo at 40° C.