t-Boc-Aminooxy-PEG-acid is a compound used in pharmaceutical research and development as a functional group. The functional groups are important components of chemical compounds that determine their chemical and physical properties. In the case of t-Boc-Aminooxy-PEG-acid, the compound contains three functional groups: a tert-butoxycarbonyl (t-Boc) protecting group, an aminooxy group, and a polyethylene glycol (PEG) chain. The t-Boc group provides protection to the amine group, which can be selectively removed under mild conditions to reveal the primary amine. The aminooxy group enables conjugation with various electrophiles, such as aldehydes and ketones, making it useful for drug discovery and development. The PEG chain enhances the solubility and biocompatibility of the compound. the introduction of t-Boc-Aminooxy-PEG-acid in pharmaceutical research and development provides a versatile functional group that can be used for drug conjugation, protein labeling, and site-specific modification of biomolecules.