General procedure for the synthesis of 6-bromo-N1-methylbenzene-1,2-diamine from 2-bromo-N-methyl-6-nitroaniline: a mixture of the product of the previous step, 2-bromo-N-methyl-6-nitroaniline (8 g, 34.62 mmol, 1.00 eq.), with zinc powder (4 g, 62.50 mmol, 2.00 eq.) in acetic acid (120 mL) was reacted at room temperature The reaction was stirred for 16 hours at room temperature. After completion of the reaction, the insoluble solids were removed by filtration and the filtrate was concentrated under vacuum. The concentrated residue was dissolved in dichloromethane (300 mL), washed with saturated sodium bicarbonate solution (100 mL), and the organic phase was dried with anhydrous sodium sulfate and concentrated again under vacuum to give the target product 6-bromo-N1-methylbenzene-1,2-diamine (4 g, 57% yield) as a black oil.LC-MS (electrospray ionization, m/z): 201.
