In a 2000mL four-necked flask, 400g (3.84mol) hydrochloric acid, 10g (0.0587mol) copper chloride and 80.0g (0.769mol) sodium bisulfite were added sequentially as a substrate, and 500g of the diazotization reaction solution was added dropwise to the substrate under stirring at -20~5, and the dropwise addition was completed in 5h, and the temperature was kept warm for 1h, and the oil layer was divided into layers at rest. Oil layer, add 400g of water, stirring 0.5h, static stratification 0.5h, the separation of oil layer, to obtain 142g (content 88%) 4-(trifluoromethoxy)benzenesulfonyl chloride, yield 84.9%.
