16817-43-9

183802-98-4

General procedure for the synthesis of 5-bromo-2-chlorophenol from 5-bromo-2-chloroanisole: BBr3 (8.2 mL, 84.9 mmol) was slowly added dropwise to a solution of 5-bromo-2-chloroanisole (18.26 g, 82.4 mmol) in dichloromethane (45 mL) under stirring conditions at 0-5 °C. The reaction mixture was stirred continuously for 4 hours at room temperature. Upon completion of the reaction, the mixture was carefully poured into a pre-cooled 2N NaOH/ice mixture and washed twice with tert-butyl methyl ether (TBME). The aqueous phase was acidified with 2N HCl to a suitable pH and then extracted again with TBME twice. All organic phases were combined and dried with anhydrous Na2SO4, followed by evaporation of the solvent under reduced pressure to afford the target product 5-bromo-2-chlorophenol as colorless crystals (16.35 g, 95% yield). The product was confirmed by 1H-NMR (400 MHz, DMSO-d6) and mass spectrometry (ES+) analysis: 1H-NMR δ (ppm): 6.97 (dd, 1H), 7.09 (d, 1H), 7.26 (d, 1H), 10.65 (bs, 1H, OH); MS (m/z) ES+: 210 (15), 208 (70, M+) , 206 (50), 179 (20), 177 (15), 63 (100).