In a 5000 L bromination reactor, 300 kg of dichloroethane, 226 kg of o-nitrotoluene and 27 kg of azobisisobutyronitrile were added sequentially. After stirring for 20 minutes, the mixed solution was transferred to a high tank and set aside; the bromination reactor was then refilled. To the reactor, 300 kg of dichloroethane and 226 kg of o-nitrotoluene were added, mixed thoroughly, then 889.03 kg of 40% hydrobromic acid was added, and the mixture was stirred at 72 to 75°C. The mixture was then transferred to the high tank and set aside for 20 minutes. From the high tank, the mixed solution was slowly added to the bromination reactor with 448.26 kg of 30% hydrogen peroxide at a 1:4 dropwise rate. After dropwise addition, the reaction was continued for 2 hours. After completion of the reaction, it was cooled to room temperature and analyzed by HPLC. The feedstock conversion was over 99.0% and no by-products such as dibrominated products were detected. The molar ratio of o-nitrotoluene, 40% hydrobromic acid and 30% hydrogen peroxide in the reaction was 1:1.2:1.2. After static partitioning, the upper aqueous phase was separated; the lower organic phase was washed with 600 L of water, and the solvent was removed by distillation under reduced pressure, and finally washed with cold dichloroethane to obtain a white 2-nitrobenzyl bromide solid product in 98.5% yield.
