- 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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- Solubility of 3-chlorophthalic anhydride and 4-chlorophthalic anhydride in organic solvents and solubility of 3-chlorophthalic acid and 4-chlorophthalic acid in water from (283.15 to 333.15) K
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The solubility of 3-chlorophthalic anhydride and 4-chlorophthalic anhydride in ethyl acetate, acetone, and 1,4-dioxane and the solubility of 3-chlorophthalic acid and 4-chlorophthalic acid in water were measured using Schreinemaker's wet residue method at
- Zhao, Hong-Kun,Ji, Hai-Zhe,Meng, Xian-Chao,Li, Rong-Rong
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body text
p. 1135 - 1137
(2010/04/30)
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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 39-40
(2009/10/22)
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- Method of making halophthalic acids and halophthalic anhydrides
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A method of preparing a halophthalic acid is disclosed which comprises the steps of contacting in a liquid phase reaction mixture at least one halogen-substituted ortho-xylene with oxygen and acetic acid at a temperature in a range between about 120° C. and about 220° C. in the presence of a catalyst system yielding a product mixture comprising less than 10 percent halogen-substituted ortho-xylene starting material, a halophthalic acid product, and less than about 10,000 ppm halobenzoic acid and less than about 1000 ppm halophthalide by-products based on a total amount of halophthalic acid present in the product mixture. In addition a method for the preparation of halophthalic anhydride is also disclosed.
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Page/Page column 7-8
(2008/06/13)
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- 2,4-DIAMINOQUINAZOLINES FOR SPINAL MUSCULAR ATROPHY
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2,4-Diaminoquinazolines of formulae I-IV and VI (I, II, III, IV and VI) are useful for treating spinal muscular atrophy (SMA).
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Page/Page column 63
(2010/02/15)
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- Method for removing impurities from oxidation products
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Disclosed is a method for removing impurities from products derived from oxidation of an ortho-dialkylaromatic compound which comprises at least one step selected from the group consisting of extraction of an aqueous solution comprising aromatic dicarboxylic acid product with an organic solvent and extraction of an organic solution comprising aromatic anhydride product with an aqueous bicarbonate solution for a time period insufficient to allow hydrolysis of anhydride to acid.
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Page column 15
(2008/06/13)
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- N-acetonylbenzamides and their use as fungicides
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Certain N-acetonylbenzamides exhibit low phytotoxicity and are useful for control of a wide range of fungi, including phytopathogenic fungi of the classes Oomycetes, Ascomycetes, Deuteromycetes and Basidiomycetes.
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- Selective removal of chlorine from chlorophthalic compounds
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Disclosed is a method of selectively removing chlorine atoms in the order of fifth position first, fourth position second, and third position third from a chlorophthalic compound having at least two ring chlorine atoms such as a chlorophthalic acid or a chlorophthalic anhydride. The chlorophthalic compound is reacted in solution with a hydrodechlorinating metal in the presence of a base.
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- COBALT CARBONYL CATALYZED POLYCARBONYLATION OF POLYHALOGENATED AROMATICS UNDER PHOTOSTIMULATION
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Cobalt carbonyl catalyzed polycarbonylation of much less reactive polychlorobenzenes could be easily achieved under photostimulation in aqueous sodium hydroxide.All these reactions could be performed without any organic solvent(in some cases, ethanol was used as a co-solvent) and any phase transfer catalyst.
- Kashimura, Tsugunori,Kudo, Kiyoshi,Mori, Sadayuki,Sugita, Nobuyuki
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p. 299 - 302
(2007/10/02)
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- Aromatic dicarboximides
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N-(4-aminophenyl)-aromatic dicarboximides, e.g. those of the formula STR1 OR SALTS THEREOF ARE ANTICONVULSANTS.
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- Aromatic dicarboxamides
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N-(4-aminophenyl)-aromatic dicarboximides, e.g. those of the formula STR1 OR SALTS THEREOF ARE ANTICONVULSANTS.
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- Synthesis of certain bis(phthalic anhydrides)
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Monomeric high molecular weight dianhydrides or tetraacids can be produced by the nucleophilic coupling of a halo substituted phthalimides acid and an aliphatic or aromatic compound having polyfunctional groups capable of reacting with the halo moiety of the phthalinide followed by hydrolysis and dehydration. Specifically, 4-chlorophthalate sodium salt is converted to an imide to reduce side reactions with the carboxylic acid groups prior to reaction with 4,4'-disodiumdiphenylene oxide sulfone or 2,2-di (4-sodium phenoxide) propane. After the reaction of the imide and the sulfone or propane compounds, the diimide formed is converted to the corresponding dianhydride.
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