117-21-5

White or pale yellow crystalline powder and chunks

3-chlorophthalic anhydride is mainly used for the synthesis of polyimide engineering plastic properties. Also be used as drug or pesticide intermediates.

[1] Preparation of 3-chlorophthalic anhydride. CA1090814A

react phthalic anhydride with chlorine in the presence of a strong non-volatile Lewis acid at a controlled rate not to exceed 50% conversion of the phthalic anhydride reactant to obtain substantially pure 3-chlorophthalic anhydride at a temperature of about 200°C. to 240°C., and re-covering said substantially pure 3-chlorophthalic anhydride.[1]