General procedure for the synthesis of 4-bromo-3-methoxyaniline from 2-bromo-5-nitroanisole: To a solution of 1-bromo-2-methoxy-4-nitrobenzene (23 g, 99.6 mmol) in tetrahydrofuran (THF, 200 mL) was added ammonium chloride (64 g, 1.2 mol) and zinc powder (78.1 g, 1.2 mol). The reaction mixture was heated to reflux overnight. After completion of the reaction, the mixture was cooled to room temperature, filtered through a bed of diatomite (Celite) and the filtrate was concentrated under reduced pressure. The concentrated residue was partitioned between water (200 mL) and ethyl acetate (200 mL). The organic layer was separated, washed with brine solution (100 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure to give 4-bromo-3-methoxyaniline (17.4 g, 87% yield) as a yellow solid. The product was confirmed by nuclear magnetic resonance hydrogen spectroscopy (1H NMR, DMSO-d6, 400 MHz): δ 7.1 (d, 1H), 6.31 (s, 1H), 6.1 (d, 1H), 5.27 (bs, 2H), 3.72 (s, 3H) ppm.
