General procedure for the synthesis of 4-(bromomethyl)-1-chloro-2-methoxybenzene from 1-chloro-2-methoxy-4-methylbenzene: to a solution of 1-chloro-2-methoxy-4-methylbenzene (274 g, 1.75 mol) in dichloromethane (2.5 L) was added benzoyl peroxide (4.23 g, 0.02 mol) and N-bromosuccinimide (NBS. 321 g, 1.80 mol). The reaction mixture was heated to reflux for 1 h under mechanical stirring. After completion of the reaction, the reaction mixture was cooled, washed sequentially with 1N hydrochloric acid (2L), saturated sodium bicarbonate solution (2L) and brine (2L), dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to afford 4-(bromomethyl)-1-chloro-2-methoxybenzene as a pale yellow solid (412 g, quantitative yield).1H NMR (400 MHz, CDCl3): δ7.30- 7.34 (d, 1H), 6.95 (s, 1H), 6.91-6.93 (d, 1H), 4.45 (s, 2H), 3.92 (s, 3H).
