Fmoc chloride is widely used in peptide synthesis as a protecting group for amino acids. It reacts with the amino group to form an Fmoc-protected amino acid, which prevents unwanted side reactions during peptide chain assembly. This protection is crucial in solid-phase peptide synthesis (SPPS), where the Fmoc group can be easily removed under mild basic conditions, allowing for sequential addition of amino acids. Its stability and selective deprotection make it a preferred choice in the production of complex peptides and proteins for pharmaceutical and biochemical research. Additionally, Fmoc chloride is employed in the synthesis of other organic compounds where temporary protection of amine groups is required.