3-Chloro-2-fluoronitrobenzene

3209-22-1

2106-49-2

General procedure for the synthesis of 3-chloro-2-fluoronitrobenzene from 2,3-dichloronitrobenzene: 500 g (2.08 mol) of 2,3-dichloronitrobenzene was added to a four-necked flask fitted with a stirrer, a thermometer, and a condenser tube, and heated to 140 °C. Subsequently, 112 g (1.93 mol) of potassium fluoride (KF) was added to the reaction system, subjected to a decompression dehydration operation and held at 140-150 °C for 3 hours. After dehydration was completed, the temperature of the reaction system was raised to 140 °C, and then 6.6 g (0.06 mol) of tetramethylammonium chloride was slowly added between 150 and 160 °C. After the addition was completed, the reaction temperature was adjusted to 165±5°C and the reaction was continued for 8 hours. At the end of the reaction, the heating was stopped and the reaction mixture was allowed to cool to room temperature and washed with deionized water. The organic phase was separated and layered by distillation to recover 100 g of unreacted 2,3-dichloronitrobenzene, and finally 240 g of the target product 3-chloro-2-fluoronitrobenzene was obtained, which had a purity of 99.6% and a yield of 87.6%.