Used in peptide synthesis as a building block, particularly for introducing chlorinated phenylalanine residues into peptide chains. It is valuable in the development of bioactive peptides and pharmaceuticals, where the chlorine atom can enhance binding affinity or modify interactions with biological targets. Commonly employed in solid-phase peptide synthesis (SPPS) due to its Fmoc protection group, which allows for selective deprotection and efficient coupling. Its applications extend to research in drug discovery, protein engineering, and the study of structure-activity relationships in peptides.