反应详情

The indole 3 (5 mmol) was added to a stirred ice-cooled solution of 1-(dimethylamino)-2-nitroethylene (0.58 g, 5 mmol) in trifluoroacetic acid (5 mL). The mixture was stirred at room temperature under N2, for 0.5 h and then poured onto ice water. The aqueous solution was extracted with ethyl acetate, the combined organic layers were washed with a saturated NaHCO3 solution and then with water. After drying over Na2SO4, the solvent was evaporated under reduced pressure to give a crude orange solid which was suspended in a mixture of EtOAc-Et2O and filtered, or chromatographed on silica gel (cyclohexane/EtOAc, 1:1, as eluent).

1. additionpoured onto ice water
2. extractionThe aqueous solution was extracted with ethyl acetate
3. washthe combined organic layers were washed with a saturated NaHCO3 solution
4. dry with materialAfter drying over Na2SO4
5. customthe solvent was evaporated under reduced pressure
6. customto give a crude orange solid which
7. filtrationfiltered
8. customchromatographed on silica gel (cyclohexane/EtOAc, 1:1, as eluent)