Used as a key intermediate in the synthesis of peptide-based pharmaceuticals. This Fmoc-protected tyrosine methyl ester serves as a doubly protected amino acid derivative, with the Fmoc group on the amino terminus and the methyl ester on the carboxyl terminus. It enables selective N-deprotection under mild basic conditions (e.g., piperidine) for coupling reactions in solution-phase peptide synthesis or fragment assembly, while the ester protects the C-terminus. The free phenolic side chain allows incorporation into peptides without additional protection in many cases. Ideal for building complex peptides in drug development, including those targeting hormones, enzymes, and receptor agonists/antagonists. Widely applied in research and industrial settings for producing high-purity biologically active molecules.