反应详情

To a mixture of 6-vinylquinoxaline (0.68 g,4.35 mMol) in dioxane (44 mL) and water (35 mL) was added osmium tetraoxide (2.5% wt in t-BuOH, 2.18 mL, 0.17 mMol) followed by sodium periodate (2.79 g, 13.1 mMol) and the reaction stirred for three hours. The solution was diluted with ethyl acetate (150 mL) and then washed with water (3×75 mL) followed by brine (75 mL). The organics were dried with magnesium sulfate, filtered, and concentrated to dryness on a rotary evaporator. Purification by flash column chromatography on silica gel using 10-20% ethyl acetate in dichloromethane as eluant yielded 470 mg (68% yield) of quinoxaline-6-carboxaldehyde as a white solid. 1H NMR (DMSO-d6): δ=10.30 (s, 1H), 9.11 (d, 2H, J=1.9 Hz), 8.74 (d, 1H, J=1.4 Hz), 8.26 (m, 2H). LC/MS (Method A), rt=0.69 mins., purity=94.8%, calculated mass=158, [M+H]+=159.

1. washwashed with water (3×75 mL)
2. dry with materialThe organics were dried with magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated to dryness on a rotary evaporator
5. customPurification by flash column chromatography on silica gel using 10-20% ethyl acetate in dichloromethane as eluant