N-Me-D-Val-OH·HCl is the hydrochloride salt of N-methyl-D-valine, a non-proteinogenic, chiral amino acid derivative. It features a methyl group on the nitrogen atom and a D-configuration at the alpha-carbon, distinguishing it from the natural L-valine. This specific stereochemistry and N-alkylation are critical for its applications. This compound is primarily employed as a key chiral building block in pharmaceutical research and development. It serves as a crucial intermediate in the synthesis of complex bioactive molecules, particularly peptides and peptidomimetics. Its most notable application is in the synthesis of certain therapeutic peptides, such as the anticancer agent dolastatin 10 and its analogs (e.g., monomethyl auristatin E, MMAE), where it is incorporated to modulate the peptide's conformation, metabolic stability, and biological activity. As a high-purity chiral synthon, it is essential for constructing specific secondary structures in medicinal chemistry. The hydrochloride salt form enhances its stability and solubility for handling in synthetic processes. It is a specialty chemical of significant value in the production of advanced drug candidates, especially in the field of antibody-drug conjugates (ADCs) where toxins like MMAE are used as payloads.