Methyl indoline-4-carboxylate hydrochloride is primarily used in pharmaceutical research and development. It serves as a key intermediate in the synthesis of various bioactive compounds, particularly those targeting neurological and psychiatric disorders. Its structure is valuable in the design of molecules that interact with specific receptors in the brain, making it useful for developing potential treatments for conditions like depression, anxiety, and neurodegenerative diseases. Additionally, it is employed in organic chemistry as a building block for creating complex heterocyclic compounds, which are essential in drug discovery and medicinal chemistry.