Used primarily as a key intermediate in the synthesis of pharmaceuticals and bioactive compounds, particularly in the development of serotonin receptor modulators and other central nervous system agents. Its aldehyde functionality allows for versatile chemical transformations, such as condensation and reduction reactions, enabling the construction of complex indole-based structures. Commonly employed in medicinal chemistry for the preparation of tryptamine and tryptophan analogs, it supports research into neurological disorders, including depression, migraine, and sleep disorders. Also utilized in the creation of fluorescent probes and dyes due to the inherent photophysical properties of the indole scaffold, making it valuable in imaging and analytical applications.