The reaction of 5-bromo-N-methyl-2-nitroaniline (350 mg, 1.51 mmol) with zinc powder (495 mg, 7.57 mmol) and ammonium chloride (810 mg, 15.15 mmol) in a solvent mixture of methanol (4 mL) and water (2 mL) was stirred for 1 h at room temperature. Upon completion of the reaction, insoluble material was removed by filtration and the filtrate was neutralized with saturated sodium bicarbonate solution. Subsequently, the reaction mixture was concentrated and extracted with ethyl acetate. The organic layer was separated, washed sequentially with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure to afford 4-bromo-2-methylaminobenzenamine as a brown solid (282 mg, 93% yield). The product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ 2.68 (3H, d, J = 4.9 Hz), 4.60 (2H, s), 4.87 (1H, d, J = 4.9 Hz), 6.32-6.58 (3H, m). The mass spectrum (ESI/APCI) showed m/z = 202.09 [M + H]+.
