Used as a versatile reagent in organic synthesis, particularly in the modification of biomolecules and polymers. It is commonly employed in the preparation of functionalized polyethylene glycol (PEG) derivatives, which are widely used in drug delivery systems to enhance solubility, stability, and bioavailability of therapeutic agents. The benzyloxy (BnO) group provides protection during synthesis, while the bromoethyl (CH2CH2Br) moiety allows for further conjugation with nucleophiles, enabling the creation of tailored macromolecules. This compound is also utilized in the development of bioconjugates, where PEG chains are attached to proteins, peptides, or other biomolecules to improve their pharmacokinetic properties. Additionally, it finds application in material science for surface modification and the creation of functionalized polymers with specific properties.