Reacción #11495

Ecuación de reacción

indole

5-Chloro-2-ethylindole

1-(dimethylamino)-2-nitroethylene

→

(E)-5-Chloro-2-ethyl-3-(2-nitroethenyl)-1H-indole

Disolventes

EtOAc Et2O

trifluoroacetic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONpoured onto ice water
2. 2
   ExtracciónThe aqueous solution was extracted with ethyl acetate
3. 3
   Lavadothe combined organic layers were washed with a saturated NaHCO3 solution
4. 4
   SecadoAfter drying over Na2SO4
5. 5
   Otrothe solvent was evaporated under reduced pressure
6. 6
   Otroto give a crude orange solid which
7. 7
   Filtraciónfiltered
8. 8
   Otrochromatographed on silica gel (cyclohexane/EtOAc, 1:1, as eluent)

Procedimiento

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).

Fuente