- Preparation method of 4, 4'-diphenyl ether tetracarboxylic dianhydride
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The invention provides a preparation method of 4, 4'-diphenyl ether tetracarboxylic dianhydride, which comprises the following steps: S1, dissolving 4-nitrophthalic acid in a solvent, and heating for dehydration; S2, adding a molybdenum salt catalyst, a halogen promoter and carbonate into the reaction liquid obtained in S1, and carrying out etherification coupling reaction to obtain a 4, 4'-diphenyl ether tetracarboxylic acid crude product; S3, refining and dehydrating the crude product obtained in S3 to obtain 4, 4'-diphenyl ether tetracarboxylic dianhydride; wherein the weight ratio of the 4-nitrophthalic acid to the solvent to the molybdenum salt to the halogen is 1: (2-3.5): (0.02-0.05): (0.1-0.3); and the molar ratio of the 4-nitrophthalic acid to the carbonate is 1: (0.55-0.75). The molybdenum powder serves as the catalyst, the halogen serves as the cocatalyst, the conversion rate of the 4-nitrophthalic acid is larger than 99%, the molar yield of the 4, 4'-diphenyl ether tetracarboxylic acid crude product is larger than 85%, the method is unique, the technological process is simple, operation is easy, the yield is high, the cost is low, and the production efficiency and economic benefits are high.
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Paragraph 0027-0035
(2021/05/29)
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- Preparation method of 4,4'-oxydiphthalic anhydride
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The invention relates to the technical field of synthesis of compounds, and particularly discloses a preparation method of 4,4'-oxydiphthalic anhydride. The preparation method comprises the followingsteps: mixing a specific compound, a solvent and a water-carrying agent, carrying out a dehydration coupling reaction at 110-155 DEG C, and carrying out cooling and crystallization to obtain 4,4'-oxydiphthalic anhydride crystals. The method has the advantages of short reaction process route, fewer byproducts and high purity and yield of the reaction product, and can be widely popularized and used.
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Paragraph 0048-0054
(2020/06/09)
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- Preparation method of 3, 3 ', 4, 4'-diphenyl ether tetracarboxylic acid dianhydride
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The invention discloses a preparation method of 3, 3 ', 4, 4'-diphenyl ether tetracarboxylic acid dianhydride, which comprises the following steps: in the presence of a basic catalyst and a phase transfer catalyst, carrying out self-condensation reaction
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Paragraph 0037-0049
(2020/07/12)
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- Preparation method of 3,3 ’, 4,4 ’ - diphenyl ether tetracarboxylic dianhydride (by machine translation)
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The refined product is subjected to, heating 3,3',4,4' - and drying dehydration to obtain the refined product of formula I ;(2) as shown :(1) in the: formula, I after heating the purified product by, N - heating, heating, refluxing, heating, refluxing, heating, refluxing, heating and, refluxing the non,protonic polar solvent,(3) ;(4), 3,3',4,4' . (by machine translation)
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- Preparation method for diphenyl ether tetracarboxylic acid dianhydride
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The invention relates to a preparation method for 3,3',4,4'-diphenyl ether tetracarboxylic acid dianhydride. The method comprises the following steps: reacting 4-chlorophthalic anhydride with potassium carbonate for 4-5h at the temperature of 162-170 DEG
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Paragraph 0009-0010; 0011-0012; 0013-0014; 0015-0016
(2018/07/30)
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- METHOD FOR PRODUCING CARBOXYLIC ANHYDRIDE AND ARYLBORONIC ACID COMPOUND
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When phthalic acid is heated in heptane under azeotropic reflux conditions in the presence of a catalytic amount of an arylboronic acid compound (such as 2,6-(diisopropylaminomethyl)phenylboronic acid or 2,6-bis(diisopropylaminomethyl)phenylboronic acid), phthalic anhydride is obtained in high yield.
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Page/Page column 10-11
(2012/01/13)
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- Bronsted base-assisted boronic acid catalysis for the dehydrative intramolecular condensation of dicarboxylic acids
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Bronsted base-assisted boronic acid catalysis for the dehydrative self-condensation of carboxylic acids is described. Arylboronic acid bearing bulky (N,N-dialkylamino)methyl groups at the 2,6-positions can catalyze the intramolecular dehydrative condensation of di-and tetracarboxylic acids. This is the first successful method for the catalytic dehydrative self-condensation of carboxylic acids.(Figure Presented)
- Sakakura, Akira,Ohkubo, Takuro,Yamashita, Risa,Akakura, Matsujiro,Ishihara, Kazuaki
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supporting information; experimental part
p. 892 - 895
(2011/05/02)
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- METHOD OF PURIFYING DIANHYDRIDES, THE DIANHYDRIDES FORMED THEREBY, AND POLYETHERIMIDES FORMED THEREFROM
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A method for purifying an oxydiphthalic anhydride comprises diluting a first mixture comprising an oxydiphthalic anhydride, a solvent, a catalyst, and an inorganic salt with a solvent, to provide a second mixture having a solids content of 10 to 30 percent based on total weight of the second mixture; filtering and washing the solids of the second mixture at a temperature below the crystallization point temperature of the oxydiphthalic anhydride to provide a third mixture; hydrolyzing the third mixture by adding water and a water-soluble acid to form a fourth mixture; heating the fourth mixture; then cooling to provide a solid-liquid mixture, optionally decanting a portion of the liquid, re diluting the remaining solid-liquid mixture, then filtering to provide a solid component; washing the solid component with water to provide a fifth mixture of oxydiphthalic tetra acid and water; ring closing the oxydiphthalic tetra acid to provide oxydiphthalic anhydride, and filtering the oxydiphthalic anhydride.
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Page/Page column 34-39
(2009/10/22)
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- Methods for Preparing Oxydiphthalic Anhydrides, Oxydiphthalic Anhydrides Prepared Thereby, and Polyetherimides Derived Therefrom
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a method for preparing an oxydiphthalic anhydride comprises contacting, under reactive and substantially anhydrous conditions in a reactor, at least one halophthalic anhydride containing more than 250 ppm chlorophthalide impurity with a carbonate of the f
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Page/Page column 5; 6
(2009/10/06)
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- METHODS FOR PREPARING OXYDIPHTHALIC ANHYDRIDES
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A method for preparing an oxydiphthalic anhydride comprises contacting, under reactive and substantially anhydrous conditions in a reactor, at least one halophthalic anhydride containing more than 250 ppm chlorophthalide impurity with a carbonate of the f
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Page/Page column 14-16; 17
(2009/10/22)
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- Method of Purifying Dianhydrides, the Dianhydrides Formed Thereby, and Polyetherimides Formed Therefrom
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A method for purifying an oxydiphthalic anhydride comprises diluting a first mixture comprising an oxydiphthalic anhydride, a solvent, a catalyst, and an inorganic salt with a solvent, to provide a second mixture having a solids content of 10 to 30 percent based on total weight of the second mixture; filtering and washing the solids of the second mixture at a temperature below the crystallization point temperature of the oxydiphthalic anhydride to provide a third mixture; hydrolyzing the third mixture by adding water and a water-soluble acid to form a fourth mixture; heating the fourth mixture; then cooling to provide a solid-liquid mixture, optionally decanting a portion of the liquid, rediluting the remaining solid-liquid mixture, then filtering to provide a solid component; washing the solid component with water to provide a fifth mixture of oxydiphthalic tetraacid and water; ring closing the oxydiphthalic tetraacid to provide oxydiphthalic anhydride, and filtering the oxydiphthalic anhydride.
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Page/Page column 11-12
(2009/10/06)
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- METHOD FOR MAKING POLYETHERIMIDES
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A method for making polyetherimides is provided by reacting a high purity dianhydride with an aromatic diamine under condensation polymerization conditions. The dianhydrides employed are purified by a method comprising contacting a first solution containi
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Page/Page column 35-36
(2008/12/05)
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- Method of purifying dianhydrides
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Disclosed herein is a method for purification of dianhydrides comprising a substantial amount (10000 ppm or more) of at least one metal salt. In one aspect the method is useful for the purification of dianhydrides prepared by the reaction of a halophthalic anhydride with a metal carbonate and may be optionally catalyzed by a phase transfer catalyst. The purification of the dianhydrides may be accomplished by hydrolyzing the dianhydride metal salt mixture directly to a tetraacid with an inorganic acid, followed by separating the impurities from an aqueous phase, and subsequently heating the tetraacid to effect ring closure to form a purified dianhydride having less than 50 parts per million metal halide and lower levels of other residual impurities. In one aspect the method is highly effective in removing phase transfer catalyst impurities such as hexalkylguanidinium halides initially present in the dianhydride undergoing purification.
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Page/Page column 12-13
(2008/06/13)
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- Method of purifying dianhydrides
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A method of preparing a purified dianhydride is provided comprising the steps of preparing a first mixture comprising water, at least one inorganic acid, and at least one dianhydride, said dianhydride comprising at least one impurity which is soluble in aqueous acid; heating said first mixture until substantially all of said dianhydride is converted to a tetraacid comprised in a second mixture; filtering at least a portion of said second mixture to provide a solid tetraacid and a filtrate, said filtrate comprising at least a portion of said impurity; and heating the tetraacid provided in a solvent with concurrent distillation of water to provide a third mixture comprising a purified dianhydride and a solvent.
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Page/Page column 8-12
(2008/06/13)
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- Method of purifying dianhydrides
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A method of preparing a purified dianhydride is provided where said method comprises the steps of preparing a first mixture comprising water, at least one inorganic acid, and at least one dianhydride, said dianhydride comprising at least one impurity which is soluble in aqueous acid heating said first mixture until substantially all of said dianhydride is converted to a tetraacid comprised in a second mixture; filtering at least a portion of said second mixture to provide a solid tetraacid and a filtrate, said filtrate comprising at least a portion of said impurity; and heating the tetraacid provided in a solvent with concurrent distillation of water to provide a third mixture comprising a purified dianhydride and a solvent.
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Page/Page column 7-8
(2008/06/13)
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- Method for preparing oxydiphthalic anhydrides using guanidinium salt as catalyst
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Oxydiphthalic anhydrides such as 4-oxydiphthalic anhydride are prepared by the reaction of a halophthalic anhydride with an alkali metal carbonate such as potassium carbonate. The reaction proceeds in the presence of a hexaalkylguaninium halide or α,ω-bis
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Page column 3-4
(2008/06/13)
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- Method for preparing oxydiphthalic anhydrides using bicarbonate as catalyst
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Oxydiphthalic anhydrides such as 4-oxydiphthalic anhydride are prepared by the reaction of a halophthalic anhydride with an alkali metal carbonate such as potassium carbonate in the presence of a catalyst system comprising an alkali metal bicarbonate such
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Page column 4
(2008/06/13)
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- Process of making selected poly(dianhydrides) compounds
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A process of making poly(dianhydride) compounds having formulae (I) and (II): STR1 where m is 0 to 50. STR2 wherein n is 0 to 20 and X is bond junction, oxygen atom, sulfur atom, SO2, C(CF3), CO, C(CH3)2, CFsub
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- O-substituted N-hydroxy hindered amine stabilizers
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Hindered amines based on various 2,2,6,6-tetraalkylated nitrogen-containing heterocyclic moieties wherein the hindered nitrogen atom on the ring is substituted with OR1 substituents and the 4-position of the ring is substituted with a variety of groups, are effective as light stabilizers in diverse substrate systems.
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- Process for the preparation of oxydiphthalic anhydride and acyloxyphthalic anhydrides
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A method for the preparation of acyloxyphthalic anhydride or oxydiphthalic anhydride which comprises the reaction of a halophthalic anhydride with an alkali metal salt and at least a catalytically effective amount of an acid or acid derivative selected from the group consisting of benzoic acids, substituted benzoic acids, benzoic acid salts or substituted benzoic acid salts, and hydrolyzable benzoyl esters, and hydrolyzable substituted benzoyl esters, alkyl carboxylic acids, hydrolyzable esters of alkyl carboxylic acids, and salts of alkyl carboxylic acids. The process may be conducted without solvent, in a polar solvent or in a non-polar solvent using a phase transfer catalyst.
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- Method for making oxydiphthalic anhydride
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Oxydiphthalic anhydride is prepared by effecting contact between a substituted phthalic anhydride such as 4-nitro or 4-fluoro phthalic anhydride and a dialkylaminopyridine in the presence of a refluxing nonpolar organic solvent.
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- Process for the preparation and recovery of oxdiphthalic anhydrides
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Oxydiphthalic anhydrides of the formula STR1 are prepared by reacting a halophthalic anhydride with potassium carbonate in: (1) a solvent-free reaction medium wherein the molar ratio of halophthalic anhydride:potassium carbonate is greater than 2:1; or (2
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