20469-65-2

106120-04-1

The general procedure for the synthesis of 5-bromo-1,3-benzenediol from 1-bromo-3,5-dimethoxybenzene was as follows: in Example 24, compound (35) (15.0 g, 69.0 mmol) was dissolved in dichloromethane (40 mL) and cooled to 0°C. A 1 M solution of boron tribromide in dichloromethane (140 mL, 140 mmol) was slowly added, keeping the reaction mixture in an ice bath. After dropwise addition, the reaction mixture was stirred at room temperature for 18 hours. Upon completion of the reaction, the reaction was quenched with methanol and the reaction mixture was subsequently concentrated. The residue was dissolved in ethyl acetate (500 mL) and washed with deionized water (300 mL). The organic layer was separated, dried over anhydrous sodium sulfate and concentrated to give the target product 5-bromo-1,3-benzenediol (45) (13.03 g, yield >99%) as an orange oil.