D-phenylglycine methyl ester ·HCl is widely used as a key intermediate in the synthesis of various pharmaceuticals, particularly in the production of beta-lactam antibiotics such as penicillins and cephalosporins. Its chiral structure makes it valuable for creating optically active compounds, which are essential in drug development to ensure efficacy and reduce side effects. Additionally, it serves as a building block in organic synthesis for producing fine chemicals and active pharmaceutical ingredients (APIs). Its application extends to the preparation of peptides and peptidomimetics, which are crucial in designing drugs targeting specific biological pathways.