Acetic Anhydride → 2,3-Dihydro-5-hydroxy-4,7-dimethyl-1H-indole-1-carbaldehyde

Participants

Reaction Steps

Acetic anhydride (25 ml, 264 mmol) was added at room temperature to formic acid (75 ml) and stirred for 30 minutes. To the solution, 2,3-dihydro-4,7-dimethyl-1H-indol-5-ol (14.4 g, 88 mmol) was added and the mixture was stirred for 2 hours. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in a chloroform methanol solution and washed: with a saturated aqueous solution of sodium hydrogen carbonate. The organic layer was washed with saturated brine and dried over sodium sulfate, and then the solvent was removed under reduced pressure. The resultant residue was washed with diisopropyl ether to obtain 6.2 g of the title compound.

Provenance & Evidence