Used as an intermediate in pharmaceutical synthesis, particularly in the preparation of bioactive molecules and drug candidates. Its structure allows for selective functionalization, making it valuable in constructing complex piperazine-based compounds. Commonly employed in the development of proteolysis-targeting chimeras (PROTACs) due to the presence of the phthalimide group, which can bind to E3 ubiquitin ligases. Also utilized in medicinal chemistry for linker design in targeted therapies, enabling conjugation between targeting ligands and effector molecules. Stable under standard conditions and compatible with various coupling reactions, it supports efficient and modular synthesis in drug discovery.