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A. Procedure for the synthesis of 5-bromo-2-hydroxybenzamide: 1. In a 100 mL round-bottom flask, 5-bromosalicylic acid (30 g, 135.5 mmol) was dissolved in n-butanol (60 mL) and concentrated sulfuric acid (95.6%, 289 μL, 5.42 mmol) was added. The unit was equipped with a Dean-Stark manifold and reflux condenser and 12 mL of n-butanol was added. 2. Reflow the reaction mixture under heat for 2 days. Upon completion of the reaction, it was cooled to room temperature and concentrated to give a light yellow oil. 3. Methanol (50 mL) was added to the above oil, followed by the slow addition of a methanol solution of ammonia (7 N, 116 mL). 4. The reaction mixture was stirred at room temperature for 2 days and the progress of the reaction was monitored by HPLC. 5. 5. After completion of the reaction, the reaction mixture was concentrated to give a white solid. 6. The crude product was washed with a small amount of ethyl acetate and hexane to give 24 g of white crystalline solid in 82% yield.