This compound is primarily used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). It serves as a protected tyrosine derivative, where the Fmoc group protects the amino group, and the HPO3Bzl group protects the phosphate moiety. This protection allows for the selective incorporation of phosphorylated tyrosine into peptides, which is crucial for studying phosphorylation events in proteins. Phosphorylation plays a significant role in cellular signaling, making this compound valuable in biochemical and pharmaceutical research. It enables the synthesis of phosphorylated peptides for use in studying enzyme activity, protein-protein interactions, and the development of therapeutic agents targeting phosphorylation pathways. Additionally, it is employed in the preparation of peptide-based vaccines and diagnostics, where phosphorylated peptides mimic natural phosphoproteins.