- Method for preparing and separating and purifying biphenyl derivatives through catalytic coupling
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The invention discloses a method for preparing and separating and purifying biphenyl derivatives by catalytic coupling, which mainly comprises the following steps: taking zinc as a reducing agent, carrying out cross-coupling to generate 3 - and 4 - biphenyldianhydrides in an aprotic solvent system and carrying out cross-coupling reaction under the ultrasonic-assisted catalysis to separate the prepared terphenyl derivatives. 3 3 ’ - 4 ’ - 4 ’ - The invention discloses a method for 3 preparing and 4 separating and purifying biphenyl derivatives by using zinc as a reducing agent 3 4 ’ . 3,3 ’ - And 4, 4 ’ - biphenyl derivatives, which are hydrolyzed and dehydrated to obtain three biphenyldianhydride isomer pure products respectively.
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Paragraph 0009; 0026; 0030; 0031; 0033; 0034; 0037
(2021/10/11)
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- Preparation and separation method of biphenyldianhydride isomer
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The method mainly comprises the following steps: taking nickel salt as a catalyst, coupling with zinc as a reducing agent, coupling with an aliphatic 3 - chloronaphthalimide and an aryl 4 - chlorosuccinimide mixture as a raw material to generate a biphenyl dianhydride derivative, and separating by using different solubility parameters and obtaining 3 and 4 ’ - respectively. 3,3 ’ - And 4, 4 ’ - biphenyl derivatives are hydrolyzed and dehydrated to obtain three biphenyldianhydride isomers, and the patent application is characterized in that a simple method for separating the three biphenyltetracarboxylic dianhydride intermediate is established.
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Paragraph 0024; 0027; 0028; 0031
(2021/10/05)
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- Method for preparing biphenyldianhydride isomer by ultrasonic-assisted catalytic coupling
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The invention discloses a method for preparing biphenyldianhydride isomers through ultrasonic-assisted catalytic coupling. The main contents include a mixture of a nickel salt catalyst and zinc as a reducing agent, 2-THF used as a solvent, an aryl (or methyl) N - chloronaphthalimide and -4 - propyl (or isopropyl) N - chlorodifluoroimide, under -3 - by means of an ultrasonic-assisted catalytic coupling reaction 60 - 100 °C 0.5 - 3 hours. The separation and purification of the three biphenyltetracarboxylic acid isomers are realized by using different solubility parameters, and the biphenyldianhydride isomer pure product is finally obtained. The invention is characterized in that a simple method for separating the three biphenyltetracarboxylic acid isomers is established, the problem of difficulty in separation of the three biphenyl dianhydride mixtures is solved, and 3,4 - biphenyl dianhydride ’ with an asymmetric structure is obtained at lower cost.
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Paragraph 0024; 0026; 0028; 0030; 0032; 0034
(2021/11/06)
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- A 2, 3, 3 ', 4' - biphenyl tetracarboxylic acid dianhydride
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The invention relates to a 2, 3, 3 ', 4' - biphenyl tetracarboxylic acid dianhydride, 4 - substituted phthalic anhydride and 3 - substituted phthalic anhydride, in a solvent, under protection of inert gas, catalyst, catalyst ligand, catalyst promoter, the presence of a reducing agent reaction, can be under mild condition, one-step reaction for preparing 2, 3, 3 ', 4' - biphenyl tetracarboxylic dianhydride.
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Paragraph 0010; 0055; 0065-0067
(2018/07/30)
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- Preparation method for biphenyltetracarboxylic dianhydride mixture
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The invention relates to a preparation method for a biphenyltetracarboxylic dianhydride mixture. The preparation method comprises the following steps: with phthalic acid as a starting raw material, carrying out an electrophilic substitution reaction so as to produce a phthalic acid derivative; then subjecting the derivative to esterification so as to produce phthalate; further catalyzing phthalate and carrying out a coupling reaction so as to produce a biphenyl tetraformate mixture; and finally, successively carrying out saponification and acidification so as to produce the product biphenyltetracarboxylic dianhydride mixture. The method provided by the invention uses cheap and easily phthalic acid as the starting raw material and is a novel low-cost easily-operatable environment-friendly production method for biphenyltetracarboxylic dianhydride; moreover, isomeric compounds of all the biphenyltetracarboxylic dianhydride are synthesized at one time in the invention, so efficiency is improved and the cost is reduced.
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Paragraph 0030; 0031
(2016/10/09)
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- PROCESS FOR PRODUCING 2, 3, 3', 4', -BIPHENYLTETRACARBOXYLIC DIANHYDRIDE
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2,3,3′,4′-biphenyltetracarboxylic acid is heat-dehydrated in a molten state at a temperature not lower than 200° C. in a flow of an inert gas in a reactor 10 having at least one reaction vessel 11 by stirring the molten material to produce 2,3,3′,4′-biphenyltetracarboxylic dianhydride. Thus obtained 2,3,3′,4′-biphenyltetracarboxylic dianhydride in the molten state is subsequently cooled and solidified in an inert gas or dry air, or cooled and solidified in the ambient air at a temperature of 40° C. or lower or 100° C. or higher.
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Page/Page column 5-6
(2009/01/24)
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- Process for production of 2, 3, 3', 4'-biphenyltetracarboxylic dianhydride
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A process for producing 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA), comprising dehydrating 2,3,3′,4′-biphenyltetracarboxylic acid in an inert gas atmosphere under heating at 180 to 195° C is disclosed. This process produces high-purity a-BPDA which is suitable for production of a polyimide.
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Page/Page column 6
(2010/11/24)
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- Diamines and photosensitive polyimides made therefrom
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Disclosed is an aromatic diamine having the general formula where A is a group containing at least one aromatic ring, each Y is independently selected from or -OR, R is a group containing at least one olefinically unsaturated group, R' is hydrogen, alkyl to C25, aryl, or R, n is 1 to 4, and the number of olefinic groups in Y is at least 3 when each Y is and otherwise is at least 2. Photosensitive polyamic acids and polyimides can be prepared from the aromatic diamines which can be crosslinked with light to a mask to form patterns on a substrate.
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- Process for producing biphenyltetracarboxylic dianhydrides
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A process for separating and purifying biphenyltetracarboxylic dianhdride isomers from a mixture of these isomers by fractional crystallization in aliphatic acid anhydrides or acetone. The isomeric mixture is obtained by heating biphenyltetracarboxylic acids, optionally in the presence of an aliphatic acid anhydride. The biphenyltetracarboxylic acids are obtained by oxidizing coupling dimers of o-xylene or by hydrolyzing coupling dimers of dimethyl phthalate.
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