公开(公告)号：US11459314B2

公开(公告)日：2022-10-04

申请号：US17049596

申请日：2019-05-06

Applicant: SABIC GLOBAL TECHNOLOGIES B.V.

Inventor： Gregory L. Hemmer ,  Sivakumar Periyasamy ,  Simon Padmanabhan ,  Robert Werling ,  Ravi Gautam

IPC: C07D405/12

Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a sieve tray extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.