Synthesis
General procedure for the synthesis of 2-iodo-4-bromo-6-nitroaniline from 4-bromo-2-nitroaniline: 4-bromo-2-nitroaniline (14.3 g, 0.0659 mol) was added in a single addition to a solution of iodine (17.6 g, 0.0692 mol) dissolved in ethanol (300 mL), followed by the addition of silver (I) sulfate (20.4 g, 0.0659 mol). The reaction mixture was stirred at room temperature for 18 hours and then filtered. The resulting solid was washed with dichloromethane until all the orange product was dissolved. The filtrates were combined and the solid obtained after vacuum evaporation was washed with a solvent mixture of ether/40-60 petroleum ether (1:1) and filtered to give 4-bromo-2-iodo-6-nitroaniline as an orange solid (19.8 g, 88% yield), which could be used in the subsequent reaction without further purification.1H NMR (400 MHz, CDCl3, δ): 6.15 (2H, br s) 8.00 (1H, s), 8.42 (1H, s).
References
[1] Journal of Organic Chemistry, 1996, vol. 61, # 17, p. 5804 - 5812
[2] Patent: WO2007/148093, 2007, A1. Location in patent: Page/Page column 14-15
[3] Journal of Organic Chemistry, 2018, vol. 83, # 17, p. 10627 - 10635
[4] RSC Advances, 2018, vol. 8, # 54, p. 30761 - 30776
[5] Patent: WO2017/19828, 2017, A1. Location in patent: Page/Page column 57
