In a 10 mL microwave reaction tube, 5-bromo-2-iodobenzoic acid (1.0 mmol), formamidine hydrochloride (1.2 mmol), CuCl2 (0.1 mmol), ligand L2 (0.1 mmol), and NaOH (4.0 equiv) were sequentially added, followed by 3.0 mL of deionized water. The reaction tube was sealed with a septum and placed in a microwave reactor. Using a CEM Discover microwave synthesizer, radiation was applied at 120 W for 20 min at room temperature, and continuous stirring was maintained during the reaction. After completion of the reaction, the solvent was removed by distillation under reduced pressure. The crude product was purified by silica gel column chromatography to afford the target compound 6-bromoquinoxalin-4-ol. The structures of all the products were confirmed by nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis.
