Used in peptide synthesis as a protected amino acid derivative, particularly in the preparation of complex peptides where selective deprotection is required. The Pht (phthaloyl) group acts as a protecting group for the amino functionality, offering stability under various reaction conditions while allowing for specific removal under mild basic or hydrazine treatment. Its application is prominent in solid-phase and solution-phase peptide coupling strategies, contributing to improved yield and purity in the final peptide product. Commonly employed in the synthesis of biologically active peptides and pharmaceutical intermediates.