Reaktion #77790

Reaktionsgleichung

HCl

5-Bromo-6-fluoro-indole

KOtBu

Di-tert.butylcarbonate

→

5-Bromo-6-fluoro-indole-1-carboxylic acid tert-butyl ester

Ausbeute 84.4%

Lösungsmittel

water

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with Et2O
2. 2
   TrocknenDrying of the organic layers with MgSO4, evaporation of the solvent, and chromatography on silica gel with hexane/EtOAc 49:1

Vorschrift

To a solution of 2.1 g (9.81 mmol) 5-Bromo-6-fluoro-indole in 35 ml of DMF were added 1.54 g (13.76 mmol) KOtBu and 3.0 g (13.76 mmol) Di-tert.butylcarbonate, and the solution was stirred for 1 hr at room temperature and 30 min at 60° C. The mixture was poured into water, acidified with 2M aqueous HCl and extracted with Et2O. Drying of the organic layers with MgSO4, evaporation of the solvent, and chromatography on silica gel with hexane/EtOAc 49:1 gave 2.6 g (84%) 5-Bromo-6-fluoro-indole-1-carboxylic acid tert-butyl ester as a colorless liquid, MS: 313 (M, 1Br).

Quelle