Used in peptide synthesis as a protected amino acid derivative, facilitating the incorporation of modified amino acids into peptide chains. The tosyl (Tos) group acts as a protecting group for the amine function, enhancing stability during coupling reactions. The benzyl ester (Obzl) protects the carboxylic acid moiety, allowing selective deprotection under mild conditions. Commonly employed in solid-phase and solution-phase synthesis of bioactive peptides, particularly where backbone modifications or specific side-chain functionalities are required. Its structure supports high coupling efficiency and minimizes racemization, making it valuable in the development of pharmaceuticals and biochemical probes.