O-Benzyl-L-Tyrosine Benzyl Ester Hydrochloride is primarily used in peptide synthesis as a protected form of tyrosine. The benzyl groups act as protecting agents for the hydroxyl and carboxyl groups of tyrosine, preventing unwanted reactions during the peptide assembly process. This compound is particularly valuable in solid-phase peptide synthesis (SPPS), where it ensures the selective deprotection and coupling of amino acids, leading to the efficient production of complex peptides. Its stability and ease of removal under specific conditions make it a preferred choice in the synthesis of biologically active peptides and pharmaceutical compounds.