Used as a versatile intermediate in organic synthesis, particularly in the development of peptide-based drugs and bioconjugates. Its Boc-protected amine group allows for selective deprotection, enabling controlled reactions in complex molecular assemblies. The PEG4 spacer enhances solubility and reduces immunogenicity, making it valuable in drug delivery systems and bioconjugation strategies. Commonly applied in the modification of proteins, antibodies, and other biomolecules to improve their pharmacokinetic properties. Also utilized in the preparation of hydrogels and other biocompatible materials for biomedical applications.