Trifluoroacetic acid → 4,6-Difluoro-2,3-dihydro-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a suspension of 4,6-difluoro-1H-indole (5 g, 32.9 mmol) in dry dichloromethane (100 mL) was added triethylsilane (10 g, 85.5 mmol) at room temperature. The reaction was then cooled to 0° C. and trifluoroacetic acid (50 mL) was added dropwise. The reaction was stirred at room temperature for 4 hours. The mixture was poured into cold saturated aqueous sodium bicarbonate solution and diluted with dichloromethane (200 mL). The layers were separated and the organic phase was dried over sodium sulfate, concentrated in vacuo, and purified by silica chromatography to give the title compound (4.5 g, 90% yield) as colorless oil.

Provenance & Evidence