701-27-9

3-Fluorobenzenethiophenol (3.4 mmol), potassium persulfate (8.6 mmol), KCl (3.4 mmol), and water (10 mL) were added to a round-bottom flask and stirred at room temperature. The reaction was slightly exothermic, and the temperature gradually increased to 45 °C. The reaction was monitored by TLC. After the reaction was complete, the reaction solution was extracted with ethyl acetate (4 × 5 mL). After separation, the organic layers were combined, dried over anhydrous Na₂SO₄, filtered, and concentrated under reduced pressure. The resulting oily product was purified by normal-phase column chromatography (60-120 mesh silica gel, n-hexane). The product fraction was collected and concentrated to give 3-fluorobenzenesulfonyl chloride as a transparent yellow liquid with a yield of 92%.