Trifluoroacetic acid → 4-Fluoro-2-methyl-1h-indole

Participants

Reaction Steps

1.43 ml of trifluoroacetic acid are added to a solution of 0.35 g of tert-butyl [3-fluoro-2-(2-oxopropyl)phenyl]carbamate in 13 ml of anhydrous dichloromethane at ambient temperature. The reaction mixture is then stirred at ambient temperature for 24 h, and is then diluted with 27 ml of dichloromethane and treated with 25 ml of a 5% sodium hydrogen carbonate solution. After stirring at ambient temperature for 1 hour and then settling out, the organic phase is separated and the aqueous phase is extracted with 25 ml of dichloromethane. The organic phases are combined, washed with saturated brine, dried over magnesium sulfate, filtered, and then concentrated to dryness under reduced pressure. 0.19 g of 4-fluoro-2-methylindole is thus obtained in the form of a dark red-colored oil, the characteristics of which are the following:

Provenance & Evidence