2-Nitroso-1,2,3,4-tetrahydroisoquinoline is primarily utilized in research and development within organic chemistry and pharmacology. It serves as a key intermediate in the synthesis of complex organic and heterocyclic compounds, which are crucial for pharmaceutical development, including bioactive substances such as anti-cancer agents and neuroactive compounds. It is also employed in studies on the formation and reactivity of nitroso compounds, including nitrosamines—known carcinogens—to understand reaction mechanisms, chemical behavior, and develop strategies for prevention and risk reduction from exposure.