611-33-6

847727-21-3

8-Chloro-3-iodoquinoline (D1) was synthesized as follows: under argon protection, N-iodosuccinimide (67.9 g, 0.30 mmol) was added batchwise to a stirred solution of 8-chloroquinoline (49 g, 0.30 mmol) in acetic acid (300 mL). The reaction mixture was heated to 70 °C and kept for 18 hours. After completion of the reaction, the mixture was concentrated under vacuum. The residue was dissolved in dichloromethane (600 mL) and washed sequentially with 10% aqueous sodium thiosulfate (2 x 300 mL) and 10% aqueous sodium bicarbonate (2 x 300 mL). The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated in vacuum to obtain the crude product. The crude product was recrystallized with ethyl acetate to give the title compound (D1) as a yellow solid (42 g, 0.145 mol, 48% yield). The recrystallized residue was further purified by silica gel column chromatography using a gradient elution with toluene/acetone to give the second product (18 g, 69% total yield).