US 11,912,689 B2
Method for isolation of an aromatic dianhydride and aromatic dianhydrides prepared by the method
Simon Padmanabhan, Mt. Vernon, IN (US); Sivakumar Periyasamy, Bangalore (IN); Gregory L. Hemmer, Mt. Vernon, IN (US); Robert John Werling, Mt. Vernon, IN (US); and Ravi Gautam, Bangalore (IN)
Assigned to SHPP GLOBAL TECHNOLOGIES B.V., Bergen op Zoom (NL)
Appl. No. 17/251,035
Filed by SHPP Global Technologies B.V., Bergen op Zoom (NL)
PCT Filed Jun. 14, 2019, PCT No. PCT/US2019/037182
§ 371(c)(1), (2) Date Dec. 10, 2020,
PCT Pub. No. WO2019/245898, PCT Pub. Date Dec. 26, 2019.
Claims priority of application No. 18178321 (EP), filed on Jun. 18, 2018.
Prior Publication US 2021/0179593 A1, Jun. 17, 2021
Int. Cl. C07D 405/12 (2006.01); C07D 307/89 (2006.01)
CPC C07D 405/12 (2013.01) [C07D 307/89 (2013.01)] 17 Claims
 
1. A method for producing an aromatic dianhydride, the method comprising
reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst under conditions effective to provide an aqueous reaction mixture comprising an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt, wherein the reacting is at a reaction temperature that is 140 to 250° C. and a reaction pressure of 1.13 to 2.16 MPa;
removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent in a single packed extraction column comprising a structured metal v-shaped packing; and
converting the aromatic tetraacid salt to the corresponding aromatic dianhydride;
wherein
the aromatic diimide is of the formula

OG Complex Work Unit Chemistry
the substituted or unsubstituted phthalic anhydride is of the formula

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the N-substituted phthalimide is of the formula

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the aromatic tetraacid salt is of the formula

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the aromatic triacid salt is of the formula

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and the aromatic imide diacid salt is of the formula

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 and
the aromatic dianhydride is of the formula

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wherein in the forgoing formulas
T is —O—, —S—, —C(O)—, —SO2—, —SO—, —CyH2y— wherein y is an integer from 1 to 5 or a halogenated derivative thereof or —O—Z—O—, wherein Z is an aromatic C6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C1-8 alkyl groups, 1 to 8 halogen atoms, or a combination comprising at least one of the foregoing;
R1 is a monovalent C1-13 organic group;
X is fluoro, chloro, bromo, iodo, or nitro;
n is 0 or 1; and
Y is a cationic group or a proton.