Used as an intermediate in the synthesis of biologically active compounds, particularly in the development of protease inhibitors. Its chiral structure makes it valuable in pharmaceutical research for creating enantioselective drugs. Commonly employed in the preparation of peptide-like molecules where the (R)-configuration is critical for biological activity. Also utilized in the construction of enzyme inhibitors targeting cysteine proteases, which are relevant in diseases such as cancer, viral infections, and inflammatory conditions. The presence of the phenylthio and chloro groups allows for further functionalization, enabling diverse derivatization in medicinal chemistry campaigns.