This derivative of L-cysteine, featuring 2-nitrophenylsulfenyl (Nps) protection on the α-amino group and benzyl protection on the thiol side chain, is primarily used in peptide synthesis. These protecting groups prevent unwanted side reactions during peptide bond formation, preserving the integrity of the amino terminus and cysteine side chain. Its application is particularly valuable in the synthesis of complex peptides and proteins, where selective protection and deprotection are critical. Additionally, it is used in biochemical research to study protein structure and function through precise control over cysteine residue modifications. The dicyclohexylammonium salt form enhances solubility and stability, making it practical for organic and aqueous reaction environments.