3-Phenylglutaric acid is primarily utilized in organic synthesis as a building block for the preparation of more complex chemical compounds. Its structure, featuring both phenyl and carboxylic acid groups, makes it a versatile intermediate in the production of pharmaceuticals, particularly in the synthesis of active pharmaceutical ingredients (APIs) that require aromatic and dicarboxylic acid functionalities. Additionally, it is employed in the development of polymers and resins, where its dual carboxylic acid groups can participate in polymerization reactions, contributing to the material's structural properties. In research, it serves as a model compound for studying reaction mechanisms and for the design of new synthetic pathways in organic chemistry.