The general procedure for the synthesis of 7-bromo-2-methoxyquinoxaline from 7-bromo-2(1H)-quinoxalinone and iodomethane was as follows: 7-bromoquinoxalin-2(1H)-one (313.1 mg, 1.391 mmol) was dissolved in 0.15 M DMF (9.2 mL), and potassium carbonate (288.4 mg, 2.087 mmol) and iodomethane ( 95.5 μL, 1.530 mmol). The reaction mixture was stirred at room temperature for 30 min. After completion of the reaction, the reaction mixture was diluted with water and extracted with ethyl acetate (2×). The organic phases were combined, washed sequentially with water (3×) and saturated saline (1×), dried over anhydrous sodium sulfate, filtered and concentrated. Purification by Biotage fast chromatography (eluent: hexane/ethyl acetate) afforded 7-bromo-2-methoxyquinoxaline (25.2 mg, 0.105 mmol, 7.6% yield). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ= 8.642 (s, 1H), 8.070-8.064 (d, 1H), 7.971-7.950 (d, 1H), 7.801-7.774 (dd, 1H), 4.045 (s, 3H).
