The general procedure for the synthesis of 2,6-difluoroiodobenzene from 1,3-difluorobenzene was as follows: n-butyllithium (n-BuLi, 42 mL, 105 mmol) was slowly added to an anhydrous tetrahydrofuran (THF, 50 mL) solution of 1,3-difluorobenzene (10.0 g, 87 mmol) over a period of 10 min at -78 °C and under nitrogen protection. Subsequently, the reaction mixture was gradually warmed to room temperature and held for 5 minutes. Next, a tetrahydrofuran (THF, 200 mL) solution of iodine (26.7 g, 105 mmol) was slowly added and the reaction mixture continued to be stirred for 4 hours at room temperature. Upon completion of the reaction, the reaction was quenched with water and the organic phase was extracted with dichloromethane (CH2Cl2), followed by washing the organic layer with brine and drying with anhydrous sodium sulfate (Na2SO4). After filtration, the target product 2,6-difluoroiodobenzene (12.5 g, 74% yield) was obtained by concentration under reduced pressure. The structure of the product was confirmed by 1H NMR (CDCl3): δ 7.24-7.30 (1H, m), 6.89 (2H, dd, J = 6.6 Hz, 8.4 Hz).
