Used in peptide synthesis as a protected amino acid derivative, enabling selective coupling and preventing side reactions at the arginine side chain. The Boc group protects the alpha-amino function, while the tosyl (Tos) group shields the guanidine moiety, ensuring stability during solid-phase or solution-phase peptide assembly. The N-methylation enhances resistance to enzymatic degradation and can influence peptide conformation, making it valuable in developing bioactive peptides with improved metabolic stability and receptor selectivity. Commonly applied in the synthesis of pharmaceutical intermediates and research compounds targeting hormonal or neurological pathways.