73 g (0.5 mole) trifluorotoluene, 150 g 95% sulfuric acid and 15 g (0.5 mole) paraformaldehyde was added to the reaction flask stirred, cooled to 15 degrees Celsius, and then about 4 hours dropwise addition of 30 g (0.252 mole) sulfinyl chloride, dropwise addition end of the reaction continued to keep warm for 4 hours, layered, the lower layer of sulfuric acid can be used for the next batch of reaction, the upper layer of the oil layer in the 0.09 to 0.099MPa The upper oil layer was subjected to decompression distillation under vacuum at 0.09-0.099MPa, and the fraction at 75-80 was collected to obtain 76g of the product 1-chloromethyl-3-trifluoromethylbenzene, yield: 78.1%.
