Used primarily in the synthesis of high-performance polymers and resins, particularly in the production of polyimides and epoxy curing agents. It contributes to thermal stability and mechanical strength in polymer chains, making it valuable in aerospace, electronics, and insulation materials. Also employed as an intermediate in the manufacture of dyes and agrochemicals due to its reactive anhydride groups. Its electron-withdrawing chlorine substituents enhance reactivity in nucleophilic substitution reactions, useful in fine chemical synthesis.