Step 2: Synthesis of 2-iodo-4-(trifluoromethyl)aniline
In a 500 mL three-necked round-bottomed flask, 4-(trifluoromethyl)aniline (22.5 g, 0.14 mol) and methanol (100 mL) were added. The reaction system was cooled to 0 °C, followed by slow dropwise addition of a dichloromethane (100 mL) solution of ICl (25 g, 0.15 mol). After the dropwise addition, the reaction mixture was stirred at room temperature for 1 hour. The reaction process was monitored by thin layer chromatography (TLC) (unfolding agent: ethyl acetate/petroleum ether = 1:10, Rf = 0.5).
Post-treatment: The reaction mixture was concentrated under reduced pressure to remove the solvent. The residue was redissolved in dichloromethane, subsequently washed with water and dried over anhydrous sodium sulfate. Finally, the dried organic phase was concentrated under reduced pressure to give 37.8 g (97% yield) of the target product 2-iodo-4-(trifluoromethyl)aniline.
Product characterization: 1H NMR (300 MHz, CDCl3) δ: 7.86 (d, J = 1.2 Hz, 1H), 7.36 (dd, J = 8.4, 1.8 Hz, 1H), 6.73 (d, J = 8.7 Hz, 1H), 4.41 (br, 2H).
