1-Ethylisoquinoline is primarily utilized in the field of organic synthesis as a key intermediate for the production of various pharmaceuticals and bioactive compounds. Its structure serves as a building block for the development of drugs targeting neurological disorders, such as Alzheimer's disease, due to its ability to interact with specific receptors in the brain. Additionally, it is employed in the synthesis of alkaloids and other heterocyclic compounds, which are essential in medicinal chemistry for their diverse therapeutic properties. In research, it is also used as a reagent or starting material for the preparation of complex molecules with potential applications in drug discovery and development.