This compound is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). It serves as a protected form of arginine, where the Fmoc group protects the amino group, and the Mtr group protects the guanidine side chain. This protection is crucial to prevent unwanted side reactions during the synthesis process. It allows for the selective deprotection of the amino group, enabling the sequential addition of amino acids to build the desired peptide chain. The Mtr group is stable under standard Fmoc deprotection conditions but can be removed selectively using specific reagents like TFA (trifluoroacetic acid) when needed. This makes it a valuable building block in the synthesis of complex peptides, especially those containing arginine residues, which are often challenging to handle due to their reactive side chains. Its application is particularly important in the production of peptides for pharmaceutical research, drug development, and biochemical studies.