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Step 3: Preparation of methyl 2-amino-5-iodo-4-(trifluoromethyl)benzoate; A solution of methyl 2-amino-4-(trifluoromethyl)benzoate (178 g, 812 mmol) in ethanol (3.3 L) was slowly added to a suspension in ethanol (5 L) containing iodine (206.1 g, 812 mmol) and silver(II) sulfate (253 g, 812 mmol). . The reaction was stirred at room temperature and under nitrogen protection for 2 hours. After completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad and the pad was washed with ethanol (2 L). The filtrate and washings were combined and concentrated under reduced pressure at 40°C to remove the solvent. The resulting residue was dissolved in ethyl acetate (7.5 L) and washed sequentially with saturated sodium bicarbonate solution (3 x 1.5 L), water (3 x 1.5 L) and brine (2 L). The organic phase was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to afford methyl 2-amino-5-iodo-4-(trifluoromethyl)benzoate as a light brown crystalline solid (276.0 g, 99% yield).

[1] Patent: WO2006/2342, 2006, A1. Location in patent: Page/Page column 56
[2] Patent: WO2006/108591, 2006, A1. Location in patent: Page/Page column 10; 66
[3] Chinese Chemical Letters, 2017, vol. 28, # 6, p. 1248 - 1251
[4] Patent: WO2013/38390, 2013, A1. Location in patent: Page/Page column 64; 65
[5] ChemMedChem, 2017, vol. 12, # 3, p. 197 - 201