This compound, a Cbz-protected amino-PEG₄-ol (tetraethylene glycol with a protected primary amine), serves as a key building block and linker in organic synthesis for peptides, complex molecules, and bioconjugates. The carbamate group protects the amine, allowing selective reactions at the terminal hydroxyl while the polyether chain enhances solubility in polar and aqueous solvents. It is particularly valuable in pharmaceutical applications, such as antibody-drug conjugates (ADCs) and targeted drug delivery systems, where mild deprotection enables precise control and minimizes impact on other functional groups.