Synthesis of 4-iodo-2-nitrotoluene: To an aqueous (40 mL) suspension of 4-methyl-3-nitroaniline (4.30 g, 28.26 mmol) cooled in an ice-water bath, 98% sulfuric acid (1.89 mL) was slowly added. Subsequently, sodium chloride was added to an ice-water bath to reduce the temperature to -2°C and a solution of NaNO2 (2.15 g, 31.10 mmol) in water (10 mL) was added at a rate that controlled the reaction temperature to not exceed -2°C. After addition, the mixture was stirred at -2°C for 45 minutes. The resulting diazonium salt solution was slowly added to the boiling NaI solution (12.89 g, 86 mmol) in batches (note: vigorous gas release). After addition, the reaction mixture was cooled to room temperature and extracted four times with dichloromethane (50 mL). The organic phases were combined, washed sequentially with saturated NaHCO3 solution (40 mL) and water (40 mL), dried over anhydrous Na2SO4 and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford 4-iodo-2-nitrotoluene (6.07 g, 82% yield).1H NMR (400 MHz, CDCl3): δ 8.28 (d, 1H, J = 1.8 Hz, Ar-H), 7.81 (dd, 1H, J = 2.2, 8.1 Hz, Ar-H), 7.09 (d, 1H, J = 8.1 Hz, Ar-H), 2.55 (d, 1H, J = 8.1 Hz, Ar-H), 7.09 (d, 1H, J = 8.1 Hz, Ar-H). Ar-H), 2.55 (s, 3H, CH3).
