Used primarily as a key intermediate in the synthesis of pharmaceuticals, particularly in the development of proteolysis-targeting chimeras (PROTACs). Its structure allows for effective linker incorporation between an E3 ligase ligand and a target protein binder, enabling targeted protein degradation. The hydrochloride salt form enhances solubility and stability, making it suitable for use in aqueous reaction conditions. It is also employed in the preparation of bioconjugates and labeled compounds for biochemical assays and drug discovery research.