Used in peptide synthesis as a building block for creating complex peptides and proteins, particularly in research and pharmaceutical development. It is often employed in solid-phase peptide synthesis (SPPS) to introduce arginine residues into peptide chains. The tosyl (Tos) protecting group helps prevent unwanted reactions during the synthesis process, ensuring the correct sequence and structure of the peptide. This compound is valuable in studying protein interactions, enzyme functions, and developing therapeutic peptides for various medical applications.