4,5-Difluorophthalic anhydride is a cyclo-anhydride compound with a wide range of applications in a variety of fields including chemicals, plastics, agrochemicals and pharmaceuticals. It can be reacted chemically with several nucleophiles, including thiocarbamoyl hydrazide and different amines, to produce carboxylic acid derivatives arising from anhydride open-circuit, i.e., phthalimide and dicarboxylic acid products.
4,5-Difluorophthalic anhydride (CPA) is located on the twofold axis of the space group C2/c; the molecules are stacked in a two-dimensional sheet. It has a similar two-dimensional molecular sheet as 5,6-dichlorobenzfurazan 1-oxide (CBF), 4,5-dibromophthalic anhydride. The disordered CBF molecule is pseudoisomeric with the CPA molecule.
