Used as a protected hydrazine reagent in organic synthesis, particularly in the preparation of heterocyclic compounds and pharmaceutical intermediates. The tert-butoxycarbonyl (Boc) group provides stability and selectivity during multi-step reactions, while the propargyl moiety allows for further functionalization via click chemistry, such as copper-catalyzed azide-alkyne cycloaddition (CuAAC). Commonly employed in the development of bioactive molecules, including protease inhibitors and kinase modulators, due to its role in forming hydrazone or triazole linkages. Also utilized in peptide chemistry for side-chain modifications and in the synthesis of labeled biomolecules for biochemical assays.