Potassium Permanganate → 4-Fluoro-1-methyl-1h-indole-3-carboxylic acid

Participants

Reaction Steps

In acetone (95 ml) was dissolved 4-fluoro-1-methylindole-3-carbaldehyde (1.43 g, 8.08 mmol), followed by the addition of potassium permanganate (a 0.2M aqueous solution, 62.0 ml, 12.4 mmol) in portions at room temperature. After the reaction mixture was stirred at room temperature for 16 hours, the precipitate was filtered off through Celite. The filtrate was distilled under reduced pressure to remove the solvent. The residue was acidified with 1N HCl. The crystals thus precipitated were collected by filtration under reduced pressure, washed with water, and dried under reduced pressure to give 4-fluoro-1-methylindole-3-carboxylic acid (0.91 g, 58%) as a brown solid.

Provenance & Evidence