3-Cl-Tyr-OH is primarily used in biochemical research as a modified amino acid to study enzyme mechanisms and protein interactions. It serves as a valuable tool in investigating the role of tyrosine residues in biological processes, particularly in understanding post-translational modifications and enzyme specificity. This compound is also utilized in the development of peptide-based inhibitors and probes for studying chlorination reactions in proteins. Additionally, it finds application in the synthesis of labeled compounds for tracking metabolic pathways and protein functions in cellular systems. Its unique structure makes it a useful intermediate in organic synthesis for creating more complex molecules with potential pharmaceutical applications.