Lithium hydroxide, monohydrate → 4-cyano-1H-indole-2-carboxylic acid

Participants

Reaction Steps

To a solution of ethyl 4-cyano-1H-indole-2-carboxylate (I-3a: 330 mg, 1.542 mmol) in ethanol (10 mL) was added LiOH.H2O (129 mg, 3.08 mmol) and the mixture was refluxed for 16 h. The solvent was evaporated under reduced pressure and the residue diluted with water (10 mL). The aqueous layer was acidified with 10% aq. HCl solution to pH 6.0 and the precipitated solid was filtered. The residue was washed with water and dried under vacuum to afford 250 mg (87%) of 4-cyano-1H-indole-2-carboxylic acid (I-3b) as an off-white solid.

Provenance & Evidence