Used as an intermediate in organic synthesis, particularly in the preparation of asparagine derivatives and modified peptides. Its phthalyl group acts as a protective moiety for the alpha-amino group, allowing selective reactions at other functional sites during peptide synthesis. After serving its protective role, the phthalyl group can be removed under mild conditions, making it valuable in stepwise synthesis of complex biomolecules. Also employed in the development of enzyme inhibitors and pharmaceutical agents where controlled functionalization of amino acids is required.