General procedure for the synthesis of 4-bromo-2-nitronaphthalen-1-amine from N-(4-bromo-2-nitronaphthalen-1-yl)acetamide: N-(4-bromo-2-nitronaphthalen-1-yl)acetamide (535 mg, 1.73 mmol) was dissolved in a mixture of 50% H2SO4 (10 mL) and EtOH (10 mL), and the reaction was stirred for 4 hours at room temperature. After completion of the reaction, the suspension was washed with ether. Filtration gave an orange solid product in 93% yield. The product was dried under vacuum and characterized by 1H-NMR (400 MHz, CDCl3) with chemical shifts of δ 8.47 (s, 1H), 8.23 (d, J = 8.4 Hz, 1H), 7.99 (d, J = 8.4 Hz, 1H), 7.78 (dd, J = 8.2, 7.2 Hz, 1H), 7.65 (dd, J = 8.1, 7.3 Hz, 1H), 7.37 (bs, 2H).
