Catalytic synthesis method of anhydride

A synthesis method and technology for carboxylic acid compounds, applied in the direction of organic chemistry and the like, can solve the problems of expensive and complex catalyst synthesis, difficult to realize industrialization, and high economic cost, and achieve economical and cheap substrates and solvents, simple substrates and solvents, and catalytic systems. simple effect

Active Publication Date: 2022-03-22
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, its reaction temperature is high, and the catalyst synthesis is expensive and complicated, and it is difficult to recycle, so the economic cost is high, and it is difficult to realize industrialization

Method used

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  • Catalytic synthesis method of anhydride
  • Catalytic synthesis method of anhydride
  • Catalytic synthesis method of anhydride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Example 1: In a 25ml three-necked flask, add 4,7-diphenyl-1,10-phenanthroline (84mg, 10mol%), phthalic acid (415mg, 2.5mmol), and finally add the solvent toluene (9mL ) and N,N-dimethylacetamide (1ml), the mixture was heated under azeotropic reflux for 12 hours, and the reflux was passed through molecular sieves to remove water. After the reaction was completed, it was cooled and filtered, and the solvent was removed to obtain 366 mg of phthalic anhydride with a yield of 99%.

[0032] The obtained product 1 H NMR data were characterized as follows: 1 H NMR (500 MHz, DMSO) δ 8.12-8.07 (m, 2H), 8.03-7.99 (m, 2H).

Embodiment 2-3

[0033] Embodiment 2-3: reduce the amount of catalyst, other reaction conditions are consistent with embodiment 1.

Embodiment 4

[0034] Embodiment 4: shorten reaction time and catalyst amount, other reaction conditions are consistent with embodiment 1.

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Abstract

The invention belongs to the technical field of acid anhydride preparation, and particularly relates to a method for preparing acid anhydride through catalytic dehydration of a carboxylic acid compound. According to the preparation method, under the condition that an N-N bidentate ligand is adopted as a catalyst, a carboxylic acid compound is heated in an inert solvent, intramolecular dehydration condensation of the carboxylic acid compound is catalyzed, and the target anhydride compound is obtained at a high yield. The method has the advantages that the catalytic system is simple, the catalytic effect is good when the catalyst amount is small, and the substrate adaptability is good; the reaction speed and the conversion rate are high; the method has the advantages of simple reaction operation and post-treatment steps, mild conditions, solvent recovery and repeated use, no pollution in the reaction process and the like, can be widely used for production and application, and has great significance in the synthesis field of carboxylic acid anhydride.

Description

technical field [0001] The invention belongs to the technical field of acid anhydride preparation, in particular to a method for preparing an acid anhydride by heating and dehydrating a carboxylic acid compound in an inert solvent by using an N-N bidentate ligand as a catalyst. Background technique [0002] At present, the classic preparation methods of acid anhydride mainly include: heating acetic anhydride to reflux with water and high temperature heating and dehydration. The post-treatment of acetic anhydride in the former method is tricky, it is difficult to completely remove the solvent, and due to the strong water absorption of acetic anhydride, the prepared anhydride is easy to absorb moisture in the air and thus hydrolyzed; the latter method usually requires Above 300 °C, the reaction conditions are relatively harsh, and it is difficult to realize it on a large scale. [0003] In addition to these two classic anhydride preparation methods, Japanese patent (JP2003146...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/89C07D307/60C07D309/32C07D493/04
CPCC07D307/89C07D307/60C07D309/32C07D493/04Y02P20/584
Inventor 罗书平商航何冉张渔方文妹彭稻
Owner ZHEJIANG UNIV OF TECH
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