反应详情

To a mixture of quinoxaline-6-carboxaldehyde (0.10 g, 0.63 mMol) in dry tetrahydrofuran (3 mL) at zero degrees was added methyl magnesium bromide (3M in Et2O, 0.253 mL, 0.76 mMol) drop wise. Upon complete addition the ice bath was removed and the solution allowed to warm to room temperature. The reaction was quenched with methanol and IN hydrochloric acid added until the pH was approximately seven. The neutral solution was partitioned between ethyl acetate and water, the aqueous layer discarded and the organics washed with brine. The organics were dried (MgSO4), filtered, and concentrated to dryness on a rotary evaporator. Purification by flash column chromatography on silica gel using 10-100% methanol in dichloromethane yielded 62 mg (56% yield) of 6-(1-hydroxyethyl)quinoxaline as a clear oil. 1H NMR (DMSO-d6): δ=8.92 (dd, 2H, J=9.1, 1.9 Hz), 8.06 (d, 1H, J=8.6 Hz), 8.02 (d, 1H, J=1.7 Hz), 7.87 (dd, 1H, J=8.7, 1.9 Hz), 5.51 (br s, 1H), 4.99 (q, 1H, J=6.4 Hz), 1.43 (d, 3H, J=6.4 Hz). LC/MS (Method A), rt=0.56 mins., purity=99%, calculated mass=174, [M+H]+=175.

1. customwas removed
2. customThe reaction was quenched with methanol and IN hydrochloric acid
3. additionadded until the pH was approximately seven
4. customThe neutral solution was partitioned between ethyl acetate and water
5. washthe organics washed with brine
6. dry with materialThe organics were dried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated to dryness on a rotary evaporator
9. customPurification by flash column chromatography on silica gel using 10-100% methanol in dichloromethane