Reacción #6798

Ecuación de reacción

potassium tert-butoxide

indole

diethyl oxalate

→

N-ethyl-indole

Disolventes

water

DMF

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrowas added in one portion at room temperature under nitrogen
2. 2
   TemperaturaThe reaction mixture was warmed
3. 3
   Temperaturato reflux under nitrogen for 1 h
4. 4
   Extracciónextracted (3×) with methylene chloride
5. 5
   LavadoThe combined organic layers were washed with brine
6. 6
   Secadodried over Na2SO4
7. 7
   Filtraciónfiltered
8. 8
   Concentraciónconcentrated in vacuo
9. 9
   OtroThe residue was purified by chromatography (SiO2, EtOAc/hexanes, 1:1)

Procedimiento

To a solution of indole product in Example 38 (150 mg, 0.572 mmol) and diethyl oxalate (92 mg, 0.63 mmol) in DMF (5 mL), potassium tert-butoxide (71 mg, 0.63 mmol) was added in one portion at room temperature under nitrogen. The reaction mixture was warmed to reflux under nitrogen for 1 h and then was cooled down to room temperature. The mixture was diluted with water (50 mL) and extracted (3×) with methylene chloride. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by chromatography (SiO2, EtOAc/hexanes, 1:1) to afford the N-ethyl-indole, Example 38, (144 mg, 86%): 1H NMR (500 MHz, CDCl3) δ 7.18-7.28 (m, 5H), 7.09 (d, J=3.2 Hz, 1H), 7.07 (d, J=8.5 Hz, 1H), 6.71 (d, J=8.5 Hz, 1H), 6.42 (dd, J=3.2, <1 Hz, 1H), 4.36 (t, J=8.0, 5.4 Hz, 1H), 4.12 (q, J=7.3 Hz, 2H), 4.00 (d, J=15.1 Hz, 1H), 3.85 (d, J=15.1 Hz, 1H), 3.07 (dd, J=11.3, 5.4 Hz, 1H), 2.66 (dd, J=11.3, 8.0 Hz, 1H), 2.50 (s, 3H), 1.44 (t, J=7.3 Hz, 3H).

Fuente