Reaktion #90423

Reaktionsgleichung

2-Butanone

4-bromophenylhydrazine hydrochloride

→

indole

Ausbeute 67.0%

5-Bromo-2,3-dimethyl-1H-indole

Ausbeute 67.0%

Lösungsmittel

EtOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated
2. 2
   Temperaturto reflux for 22 h
3. 3
   Einengenconcentrated in vacuo
4. 4
   Sonstigepartitioned between EtOAc and 1N HCl
5. 5
   WaschenThe organic layer was washed with H2O and saturated aqueous NaHCO3
6. 6
   Trocknendried over Na2SO4
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated
9. 9
   SonstigeThe crude residue was purified by chromatography (SiO2, 0-20% EtOAc/Hexane)

Vorschrift

Following a published procedure (Gundersen, E. G. U.S. Patent App. Publ. US 2005/070592) 2-Butanone (0.11 mL, 1.278 mmol) was added to a solution of 4-bromophenylhydrazine hydrochloride (0.300 g, 1.342 mmol in EtOH (3.8 mL). The mixture was heated to reflux for 22 h, concentrated in vacuo, and partitioned between EtOAc and 1N HCl. The organic layer was washed with H2O and saturated aqueous NaHCO3, dried over Na2SO4, filtered, and concentrated. The crude residue was purified by chromatography (SiO2, 0-20% EtOAc/Hexane) to afford the desired indole as a pink powder (200 mg, 67%).

Quelle