This compound is widely used in peptide synthesis as a protecting group for cysteine residues. The Boc (tert-butyloxycarbonyl) group shields the amino group, while the S-(4-methylbenzyl) moiety protects the thiol group of cysteine during the synthesis process. This ensures selective reactivity and prevents unwanted side reactions. It is particularly valuable in the production of complex peptides and proteins, where precise control over the sequence and structure is essential. Additionally, it finds application in the development of pharmaceuticals, especially in the synthesis of peptide-based drugs that require specific disulfide bond formations for their biological activity.