54395-38-9Relevant articles and documents
Preparation method of aromatic diether dianhydride
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Paragraph 0075; 0076, (2019/12/02)
The invention relates to a preparation method of aromatic diether dianhydride, which comprises the following steps: (1) pouring a bisphenol compound, N-substituted phthalimide and a catalyst into a mixed solvent, carrying out heating reflux to remove water and carrying out substitution reaction to obtain N-substituted diether imide; (2) adding alkali metal hydroxide and water into the N-substituted diether imide obtained in the step (1), heating the mixture, carrying out hydrolysis reaction, cooling, adding protonic acid, separating out solid, collecting the solid, and drying the solid; and (3) dissolving the dried solid in a mixed solution of acetic acid and acetic anhydride, carrying out heating reflux, cooling, filtration and solid collection in sequence, recrystallizing the collected solid with a mixed solution of acetonitrile and toluene, performing filtration, collecting the solid, and drying the solid to obtain the product. The preparation method of the aromatic diether dianhydride has the advantages that the steps are simplified, the consumed time is short, the used solvent is easy to recycle and can be repeatedly used, and the prepared product aromatic diether dianhydrideis high in purity and yield.
Method of making aromatic bis(ether ortho phthalic acid)s
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, (2008/06/13)
Aromatic bis(ether anhydride)s can be made by a nitro displacement of an N-substituted nitrophthalimide with an alkali diphenoxide to produce an intermediate aromatic bis(etherphthalimide). Hydrolysis of the aromatic bis(etherphthalimide) to the corresponding tetra-acid salt followed by acidification and dehydration, results in the production of the aromatic bis(ether anhydride). These anhydrides can be used as intermediates for making polyimides. The intermediate aromatic bis(etherphthalimide) can be employed as a plasticizer in polyimide resins.