3,4-Dihydroisoquinoline is widely utilized in the pharmaceutical industry as a key intermediate in the synthesis of various bioactive compounds. It serves as a building block for the development of drugs targeting neurological disorders, such as Parkinson's disease and Alzheimer's disease, due to its structural similarity to neurotransmitters. Additionally, it is employed in the creation of analgesics and antihypertensive agents, showcasing its versatility in medicinal chemistry. In research, it is used to study enzyme inhibition and receptor binding mechanisms, aiding in the discovery of new therapeutic agents. Its derivatives are also explored for their potential anticancer properties, making it a valuable compound in drug discovery and development.