Used in peptide synthesis as a protected amino acid building block, particularly in the development of pharmaceuticals and bioactive peptides. The Boc (tert-butoxycarbonyl) group acts as a protecting group for the amine, allowing selective reaction at the carboxylic acid during coupling steps. The 3-methoxy substitution on the phenylalanine side chain provides electronic and steric modulation, which can influence peptide conformation, receptor binding, or metabolic stability. Commonly employed in solid-phase and solution-phase synthesis of complex peptides, including those with therapeutic potential in neurological and hormonal disorders.