Used primarily in peptide synthesis, it serves as a protected cysteine derivative. The Boc group safeguards the amino functionality, while the Acm group protects the thiol side chain, preventing unwanted reactions during peptide chain assembly. The ONp (para-nitrophenyl) ester facilitates efficient coupling with other amino acids or peptides. This compound is particularly valuable in solid-phase peptide synthesis (SPPS) and solution-phase methods, enabling the construction of complex peptides with precise cysteine incorporation. It is also employed in the synthesis of peptides requiring selective deprotection of cysteine residues for disulfide bond formation, which is crucial in biologically active peptides and proteins.