The general procedure for the synthesis of 3-bromo-4-iodonitrobenzene from 2-bromo-4-nitroaniline is as follows: a pre-cooled solution of sodium nitrite (57.2 g, 829 mmol) and potassium iodide (138 g, 829 mmol) dissolved in water (25 mL) was added dropwise to a stirred 2-bromo-4-nitroaniline (60 g 276 mmol) in acetonitrile (250 mL) suspension. After the dropwise addition was completed, the reaction mixture was continued to be stirred at 0-5 °C for 30 min. Upon completion of the reaction, the reaction mixture was slowly poured into pre-cooled water (1000 mL). The precipitated solid product was collected by filtration, washed with water several times and then dried to give the target compound 3-bromo-4-iodonitrobenzene. Yield: 70.0 g in 77% yield. The product characterization data were as follows: 1H NMR (300 MHz, CDCl3): δ 7.86 (dd, 1H, J = 8.7, 2.4 Hz, Ar-H), 8.10 (d, 1H, J = 8.7 Hz, Ar-H), 8.45 (d, 1H, J = 2.4 Hz, Ar-H); MS (EI, 70 eV): m/z 328.3 (M + H).
