Ammonium Chloride → 5-Bromobenzene-1,3-diamine

Ammonium chloride (5.20 g, 97 mmol) was added to a stirred, cooled (room temperature) mixture of 1-bromo-3,5-dinitrobenzene (20 g, 81 mmol) and iron (54.3 g, 972 mmol) in ethanol:water (2:1) and the mixture was stirred at 80° C. for 1 h. The heterogeneous reaction was filtered on celite while hot, concentrated, and diluted with brine. The product was extracted with ethyl acetate, the organic layer washed with brine and dried over Na2SO4. The residue was dissolved in boiling ethyl acetate (˜75 mL), a bit of hexanes was added to form a layer on top of ethyl acetate (˜7.5 mL) and the mixture was left to crystallize overnight. The crystals were filtered, washed with diethyl ether and air-dried to give 5.77 g of 5-bromobenzene-1,3-diamine as a grey solid. MS ESI: [M+H]+ m/z 187.0 and 189.0.