Used in solid-phase peptide synthesis as a protected amino acid derivative, particularly for incorporating modified arginine residues into peptide chains. The Fmoc group allows for mild base-labile protection, enabling stepwise assembly of peptides under basic conditions while maintaining compatibility with other protecting groups. The bis(methylamino)methylene moiety stabilizes the guanidine function, reducing side reactions during synthesis. Commonly applied in the preparation of bioactive peptides, enzyme inhibitors, and peptide-based pharmaceuticals where precise arginine mimicry is required. Its structure supports high solubility in common organic solvents, facilitating efficient coupling and purification steps in automated peptide synthesis.