Applications
Indole-5-carboxylic acid is the suitable reagent used to study the intermolecular excited state proton transfer in indole-2-carboxylic acid and indole-5-carboxylic acid in various solvents in acidic, basic, and neutral media by steady state and time resolved fluorescence spectroscopy. It may be used in the electrochemical synthesis of poly(indole-5-carboxylic acid) (PICA) films. Also used as reactant for preparation of tryptophan dioxygenase inhibitors pyridyl-ethenyl-indoles, as potential anticancer immunomodulators, synthesis of indirubin derivatives and amide conjugates with ketoprofen, as inhibitors of Gli1-mediated transcription in Hedgehog pathway.

Solubility
Soluble in ethanol (50 mg/ml), dimethyl sulfoxide and methanol.

Notes
Store in cool place. Keep container tightly closed in a dry and well-ventilated place. Store away from oxidizing agent.