Diphenaldehyde is primarily used in organic synthesis as an intermediate for the preparation of various heterocyclic compounds and pharmaceuticals. It serves as a building block in the development of complex molecules due to its reactive aldehyde groups, which readily undergo condensation and cyclization reactions. It finds application in the synthesis of dyes, fragrances, and functional materials where aromatic and carbonyl functionalities are required. Additionally, it is employed in research settings for the design of novel organic compounds with potential biological activity.