- Method for preparing rod-like bisphenol A type diether diphthalimide
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The invention relates to a method for preparing rod-like bisphenol A type diether diphthalimide. The method comprises the following steps: (A) enabling bisphenol A to react with a strong base in a nonpolar solvent so as to prepare a bisphenol A salt; (B) conducting a nucleophilic reaction on the bisphenol A salt with phthalimide in a polar aprotic solvent; and (C) separating a reaction liquid froma hot alcohol type solvent with an additive, conducting filtration so as to obtain a crude product filter cake of diether diphthalimide, conducting heating backflow on the filter cake in an alcohol solvent for multiple times, and conducting filtration and drying, so as to obtain the rod-like bisphenol A type diether diphthalimide with high purity. By adopting the method, the problems that in a conventional production technique, diether diphthalimide is liable to cake and aggregate when being separated, and crystal granules are small and hard to filter, can be solved, a rod-like product of good dispersibility and large granules is prepared, the filtration efficiency is greatly improved, and in addition, the obtained rod-like bisphenol A type diether diphthalimide is high in purity and convenient in downstream use.
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Paragraph 0037; 0038
(2019/10/01)
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- Preparation method for diether diphthalimide
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The invention discloses a method for preparing diether diphthalimide. The method comprises the following steps: step (A): in a reaction kettle, enabling a diphenol raw material to react with one or more of strong base and strong alkali and weak acid salt in a non-polar solvent, such as methylbenzene or o-xylene, under an inert atmosphere; and step (B): enabling a reaction product of the step (A) to react with phthalimide in the presence of an ionic liquid catalyst, to obtain the diether diphthalimide. The method is capable of performing a nucleophilic reaction in the non-polar solvent, addingionic liquid as a phase transfer catalyst, and improving a reaction yield. After ending the reaction, impurities are removed through a water extraction method, and wastewater generation is greatly reduced. The diether diphthalimide is obtained by reducing a pressure and evaporating an organic layer, a process is simple, and an obtained product is high in purity.
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Paragraph 0046; 0047; 0048; 0049; 0054; 0055
(2019/05/22)
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- Preparation method of low-yellowness diether diphthalimide
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The invention relates to a preparation method of low-yellowness diether diphthalimide. The method comprises the following steps: (A) performing a reaction on diphenol with strong alkali in a non-polarsolvent to prepare diphenol salt; (B) carrying out a nucleophilic reaction on the product obtained in the step A and phthalimide in a polar aprotic solvent; and (C) after the reaction in the step (B)is finished, introducing chloromethane and/or chloroethane gas into the system to prepare the diether diphthalimide. By adopting chloromethane and/or chloroethane gas to react with residual phenolichydroxyl/phenolate end groups to generate stable alkyl, the method solves the problems that a diether diphthalimide product is yellowed in color and is easy to oxidize and yellow in the existing production technology process.
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Paragraph 0034; 0035; 0036; 0037; 0040-0043
(2019/10/01)
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- Preparation method of aromatic diether dianhydride
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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.
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Paragraph 0051; 0052; 0063; 0064
(2019/12/02)
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- METHODS FOR THE MANUFACTURE OF AN AROMATIC BISIMIDE AND A POLYETHERIMIDE
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A method for producing an aromatic bisimide includes reacting a dialkali metal salt of a dihydroxy aromatic compound with an N-alkyl nitrophthalimide to form a product mixture including the aromatic bisimide. The N-alkyl nitrophthalimide includes 4-nitro-N-(C1-13 alkyl)phthalimide, 3-nitro-N-(C1-13 alkyl)phthalimide, or a combination including at least one of the foregoing, and 4-hydroxy-3,5-dinitro-N-(C1-13 alkyl)phthalimide in an amount of 1-10000 ppm. The aromatic bisimide can be obtained in a yield of greater than 75%, or 90-99.8%. A method for the manufacture of a polyetherimide, a polyetherimide, and an article including the polyetherimide are also disclosed. A mixed acid nitration process for the preparation of an N-alkyl nitrophthalimide is also described.
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Paragraph 0072; 0077-0080; 0085-0089
(2017/07/14)
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- N-Hydroxyphthalimide catalysts as bioactive pro-oxidants
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The catalytic role of N-hydroxyphthalimide (NHPI) in promoting free-radical hydrogen atom transfer (HAT) reactions, well-documented for processes of industrial and synthetic interest, is here investigated for the first time in a biological environment. While NHPI by itself did not show any bioactivity, selected NHPI-derivatives (NHPIDs) revealed the ability to activate the intracellular formation of reactive oxygen species (ROS), causing the depletion of glutathione (GSH) levels and an increase in oxidative stress (OS). The evident bioactivity of some of these derivatives resulted in a significant reduction of the viability in osteosarcoma MG-63, suggesting a new, potential role of NHPIDs as pro-oxidant drugs. The key role of the N-OH group in promoting oxidative stress is demonstrated.
- Melone,Tarsini,Candiani,Punta
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p. 21749 - 21755
(2016/03/08)
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- PRODUCTION OF LOW COLOR POLYETHERIMIDES
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The production of low color polyetherimides, including its intermediates, such as bisimides and diaryl diether dianhydrides, may be affected by producing an improved purity intermediate of 4-nitro-N-alkylphthalimide. A salt, such as alkali metal carbonate or alkali metal hydrogen carbonate, is added to an aqueous mixture of 4-nitro-N-alkylphthalimide and 3-nitro-N-alkylphthalimide to selectively hydrolyze the imide linkage of 3-nitro-N-alkylphthalimide forming a water-soluble acid-amide salt. An organic solvent is added to this salt mixture to phase separate 4-nitro-N-alkylphthalimide having dissolved in the organic solvent from acid-amide salt of 3-nitro-N-alkylphthalimide having dissolved in water.
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Page/Page column 11
(2009/12/05)
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- Method for making aromatic ether imides
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A method for making aromatic ether imides is provided by effecting the displacement of reactive radicals on a phthalimide nucleus with a mono- or bis-alkali metal phenoxide in the presence of a nonpolar solvent and a phase transfer catalyst, such as a tetra-ammonia salt. The aromatic ether imides made by the present invention are useful intermediates for making aromatic ether anhydrides and aromatic bis(ether anhydrides).
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