General procedure for the synthesis of 8-aminoisoquinolines from 5-bromo-8-nitroisoquinolines: 5-bromo-8-nitroisoquinolines (1.00 g, 3.95 mmol) were dissolved in methanol (70 mL), and hydrogenation was carried out by adding palladium/activated charcoal (10% Pd, 200 mg) as a catalyst for 18 hr at room temperature and atmospheric pressure. Upon completion of the reaction, the reaction mixture was filtered through Celite to remove the catalyst. The filtrate was concentrated and purified by column chromatography (eluent: ethyl acetate/heptane) to afford the target compound 8-aminoisoquinoline (100 mg, 18% yield) as a greenish-brown solid.1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 8.32 (d, 1H), 7.54 (d, 1H), 7.40 (dd, 1H) , 6.99 (d, 1H), 6.72 (d, 1H), 6.22 (s, 2H).
