1,2,3,4-Tetrahydroisoquinoline-6-carboxylic acid is primarily used in the field of medicinal chemistry and drug development. It serves as a key intermediate in the synthesis of various biologically active compounds, particularly those targeting neurological disorders. The compound's structure is often utilized to develop molecules with potential therapeutic effects, such as inhibitors for enzymes involved in neurodegenerative diseases. Additionally, it is employed in the creation of analogs for studying structure-activity relationships, aiding in the optimization of drug candidates. Its applications also extend to research focused on cardiovascular and anti-inflammatory agents, where its core structure is modified to enhance efficacy and selectivity.