Used primarily as an intermediate in the synthesis of pharmaceutical compounds, particularly in the development of active pharmaceutical ingredients (APIs) where piperazine rings are required. Its main application lies in peptide coupling and the construction of complex heterocyclic systems. The Cbz-protected piperazine moiety allows selective reactivity at another site of the molecule, making it valuable in multi-step organic syntheses. It is especially useful in medicinal chemistry for creating protease inhibitors, receptor antagonists, and kinase inhibitors. Due to the presence of the carbonyl chloride group, it readily reacts with amines and alcohols to form amides and esters, enabling efficient derivatization. Its stability under various reaction conditions and ease of deprotection make it a preferred building block in drug discovery and development.