To a suspension of 2,3-dichloroquinoxaline (300 mg, 1.51 mmol) in methanol (15 mL) and N,N-dimethylformamide (1.0 mL), sodium methanolate (28% methanol solution, 309 mg, 1.66 mmol) was slowly added at 0 °C. After addition, the reaction mixture was stirred at room temperature for 2 hours. After completion of the reaction, the mixture was concentrated in vacuum. The residue was diluted with chloroform and water, the organic layer was separated through a partition funnel and concentrated again under vacuum. The resulting crude product was purified by silica gel column chromatography, the eluent being a gradient from pure hexane to hexane:ethyl acetate (19:1), to afford 2-chloro-3-methoxyquinoxaline (as described in Reference Example 20) as a colorless powder (251 mg, yield not provided).
