402-45-9

463976-21-8

S3. 4-(Trifluoromethyl)phenol (6) (241 mmol, 39 g) was dissolved in a solvent mixture of tetrahydrofuran (200 mL) and water (200 mL) under stirring conditions. Iodine (265 mmol, 67 g) and sodium carbonate (265 mmol, 28 g) were added sequentially. The reaction mixture was stirred at room temperature for 24 h. The progress of the reaction was monitored by TLC until 4-(trifluoromethyl)phenol (6) was fully reacted. Post-treatment step: 5% aqueous thiourea solution was added to quench unreacted iodine, followed by three extractions with ether. The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product. The crude product was purified by column chromatography with the eluent being a mixed solvent of petroleum ether and dichloromethane (the volume ratio was tapered from 10:1 to 6:1) to afford the target compound 2-iodo-4-(trifluoromethyl)phenol (7) (42.7 g) in 63% yield.