- A 3, 3 ', 4, 4' - diphenyl sulphone four carboxylic anhydride method (by machine translation)
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The invention discloses a 3, 3 ', 4, 4' - diphenyl sulphone four carboxylic anhydride method. Comprising the following steps: 1) the 4 - dissolved in dimethyl sulfoxide in daily, then adding sulfur and unclesodium butylate, heating up to 40 °C into the carbon bisulfide, until the raw material after the reaction is complete, the pressure recovery part of the solvent, the residue added to the water, filtering, washing, drying to obtain 3, 3 ', 4, 4' - diphenyl thioether tetra carboxylic acid anhydride; 2) 3, 3 ', 4, 4' - diphenyl thioether tetra carboxylic acid anhydride is dissolved in acetonitrile, added to ammonium nitrate and four-butyl iodide and water, the heating conditions are added to the potassium sulfate in batches under the, to 3, 3 ', 4, 4' - diphenyl thioether tetra carboxylic acid anhydride and after the reaction is complete, water is added to the reaction solution, lowering the temperature to 5 °C filtering, washing, drying, to obtain 3, 3 ', 4, 4' - diphenyl sulphone four carboxylic acid anhydride. The present invention provides a preparation of 3, 3 ', 4, 4' - diphenyl sulphone four carboxylic acid anhydride method has the following advantages: easy to purchase of raw materials, the reaction solvent can be recycled, simple post treatment operation, high yield, good product quality and environmental pollution is relatively small and the like. (by machine translation)
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Paragraph 0009; 0030; 0033; 0036; 0039; 0042
(2017/08/28)
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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 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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- 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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- N-cyanoimides
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Polyfunctional N-cyanoimides and their precursors and derivatives are disclosed along with methods for their preparation and interconversion. Also disclosed are curable compositions comprising the N-cyanoimides or poly(amide-cyanoamides) and reactive diluents as well as novel dianhydrides, polyimides, and poly(amide-cyanoamides) and methods for making them.
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