A 500 mL flask was charged with 25.2 g of sodium sulfite, 100 mL of water, and 16.8
g of sodium bicarbonate. Heat to reflux and after all the solids are dissolved, add 21.0 g of 4-fluorobenzenesulfonyl chloride in batches and continue to heat to reflux for 4 hours. Cool to 40
??C, 18.9 g of dimethyl sulfate was added dropwise from the dispensing funnel, with a dropwise acceleration to maintain the system temperature at 40~45
?? is appropriate. After dropping, the reaction was held for 2.5 h. After the methylation reaction was complete, the reaction was heated and refluxed for 1 h. The reaction was then heated and refluxed. Add 200mL of water, static cooling to room temperature, precipitated a large number of solids, filtered, washed with water, that is, p-fluorobenzenesulfone.
