Used in peptide synthesis as a protected amino acid derivative, enabling selective coupling reactions while preventing unwanted side reactions at the lysine side chain. The BOC group protects the epsilon amine of lysine, and the methyl ester shields the C-terminal carboxylic acid, allowing stepwise assembly of complex peptides. Commonly applied in solid-phase and solution-phase synthesis for pharmaceutical research, including the development of bioactive peptides and protein mimetics. Stable under standard handling conditions and easily deprotected for further functionalization.