Z-N-Me-Asp(OtBu)-OH·DCHA is a protected aspartic acid derivative, specifically an N-methylated and side-chain tert-butyl ester protected form with a benzyloxycarbonyl (Z) group on the amine. It is supplied as a dicyclohexylamine (DCHA) salt to enhance stability and crystallinity. This compound is a non-natural, sterically hindered amino acid building block. Its primary application is in the field of peptide chemistry and medicinal chemistry as a specialized synthetic intermediate. It is used in the solid-phase and solution-phase synthesis of modified peptides, particularly for introducing N-methylated aspartic acid residues. N-methylation is a key strategy to improve the metabolic stability, membrane permeability, and bioavailability of peptide-based drug candidates, making this compound valuable for developing peptide therapeutics and peptidomimetics. The Z group provides orthogonal protection for the α-amino group, while the OtBu group protects the side-chain carboxylic acid, allowing for selective deprotection and sequential coupling in complex peptide assembly. Its use is critical in research focused on creating constrained peptide structures with enhanced pharmacological properties.