Under nitrogen protection, 2.0 g (11.76 mmol) of o-chlorophenylacetic acid (Aldrich) and 2.1 g (11.76 mmol) of N-bromosuccinimide (NBS, Aldrich) were dissolved in 60 mL of carbon tetrachloride (CCI4). Subsequently, 569 mg (2.35 mmol) of benzoyl peroxide (Fluka) was added to the solution. The reaction mixture was stirred at 80°C for 5 hours. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The crude product was purified by fast chromatography using a 50 g silica gel column with a solvent mixture of dichloromethane (DCM) and ethyl acetate (AcOEt) (10:0 to 5:5 gradient) as eluent. After removing the solvent under reduced pressure, 2-bromo-o chlorophenylacetic acid (1.7 g, 48% yield) was obtained.1H-NMR (400 MHz, CDCl3) data were as follows: δ 5.95 (1H, s), 7.35 (3H, m), 7.80 (1H, d).
