1823-59-2Relevant articles and documents
Preparation method of 4, 4'-diphenyl ether tetracarboxylic dianhydride
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Paragraph 0027-0035, (2021/05/29)
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.
Preparation method of 4,4'-oxydiphthalic anhydride
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Paragraph 0048-0054, (2020/06/09)
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.
Preparation method for diphenyl ether tetracarboxylic acid dianhydride
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Paragraph 0009-0010; 0011-0012; 0013-0014; 0015-0016, (2018/07/30)
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