Used in organic synthesis as an intermediate for pharmaceuticals and biologically active compounds. Serves as a building block in the development of indole-based drugs, particularly in the design of anti-inflammatory and central nervous system agents. Also employed in research settings for the preparation of fluorescent probes and sensors due to the inherent photophysical properties of the indole scaffold. Its carboxylic acid functionality allows for easy derivatization, making it valuable in combinatorial chemistry and medicinal chemistry for constructing compound libraries.