反应详情

1,4-Dibromo-2,5-difluorobenzene (100 g, 0.37 mol) is dissolved in concentrated sulfuric acid (200 g) and treated with fuming nitric acid (56 g, 0.44 mol, HNO3 content >90%) by drop-wise addition at an internal temperature that is maintained between 50–60° C. After the addition is complete, the mixture is cooled to room temperature and stirred for 12 hours, then poured into ice-water (1000 mL). The suspension is extracted with EtOAc (3×500 mL). The combined organic extracts are dried (MgSO4) and concentrated by rotary evaporator to give 2,5-dibromo-3,6-difluoronitrobenzene as an oily yellow solid.

1. temperatureis maintained between 50–60° C
2. additionAfter the addition
3. extractionThe suspension is extracted with EtOAc (3×500 mL)
4. dry with materialThe combined organic extracts are dried (MgSO4)
5. concentrationconcentrated by rotary evaporator