3-Benzalphthalide is primarily used in the synthesis of organic compounds, particularly in the production of dyes and pigments. Its structure makes it a valuable intermediate in creating colorants for textiles, plastics, and inks. Additionally, it is employed in research and development for studying chemical reactions and mechanisms, especially in the field of organic chemistry. Its applications also extend to the pharmaceutical industry, where it serves as a building block for the synthesis of various active pharmaceutical ingredients (APIs).