General procedure for the synthesis of 4-bromo-N1-methylbenzene-1,2-diamine from 4-bromo-N-methyl-2-nitroaniline: to a solution of 4-bromo-N-methyl-2-nitroaniline (2.1 g, 9 mmol) in methanol (MeOH, 50 mL) was added iron powder (Fe, 2.5 g, 45 mmol) and ammonium chloride (NH4Cl, 4.8 g, 90 mmol). The reaction mixture was stirred at 80 °C for 4 hours. After completion of the reaction, the mixture was poured into water (H2O, 60 mL) and extracted with ethyl acetate (EA, 40 mL × 2). The organic layers were combined, dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure to give 4-bromo-N1-methylbenzene-1,2-diamine (2.0 g, 99% yield) as a yellow solid.LC-MS m/z: 203.1 [M + H]+. Retention time (tR) = 1.64 min.
