Phthalic Anhydride

Phthalic anhydride, the anhydride of phthalic acid, is a white solid. It is used as a chemical intermediate to prepare phthalate ester plasticizers for synthetic resins, modifiers for rubber and dyes. It is also used as a monomer for synthetic resins (alkyd, glyptal, and polyester). It is employed for the synthesis of primary amines, phthalylsulfathiazole (intestinal antimicrobial agent), and phaltan/thalidomide (agricultural fungicide).