Method for synthesizing N-benzyl maleimide from immobilized supported acid catalyst

A maleimide, catalyst-loaded technology, applied in chemical instruments and methods, organic chemistry, chemical/physical processes, etc., can solve the problems of large pollution in the production process, easy wear and tear of catalysts, and many production processes, and reduce waste. Acid content, reduction of water washing, and simplification of the production process

Inactive Publication Date: 2010-11-03
广东光华化学厂有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the invention is to provide a kind of immobilized loading acid catalyst synthetic N-phenylmaleimide in order to solve the low productive rate of existing synthetic method, big pollution in production process, many production procedures, easy wear and tear of catalyzer etc. method

Method used

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  • Method for synthesizing N-benzyl maleimide from immobilized supported acid catalyst

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Experimental program
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Effect test

Embodiment 1

[0018] 1) with 10% H 3 PO 4 The equal volume of the solution was impregnated with silica gel for 6 hours, then vacuum-dried and dried at high temperature to obtain a loaded catalyst; then 4 grams of loaded catalyst was packed into a stainless steel mesh and fixed on a stirrer;

[0019] 2) 9.3 grams of aniline and 8.8 grams of maleic anhydride were added to 70 milliliters of xylene for acylation, stirred, heated at a temperature of 100° C., and reacted for 0.5 hours to obtain an N-phenylmaleamic acid solution;

[0020] 3) Add N-phenylmaleamic acid solution, 0.2 g of hydroquinone and a supported catalyst into a dehydration reactor for dehydration and ring closure, the reaction temperature is 160° C., the reaction time is 1 hour, and the solvent is removed under reduced pressure to obtain Crude N-phenylmaleimide;

[0021] 4) The obtained crude N-phenylmaleimide was recrystallized in 200 ml of cyclohexane to obtain N-phenylmaleimide with a yield of 92%.

Embodiment 2

[0023] 1) with 10% H 3 PO 4 The equal volume of the solution was impregnated with silica gel for 6 hours, then vacuum-dried and dried at high temperature to obtain a loaded catalyst; then 2 grams of loaded catalyst was packed into a stainless steel mesh and fixed on a stirrer;

[0024] 2) 9.3 grams of aniline and 9.2 grams of maleic anhydride were added to 70 milliliters of xylene for acylation, stirred, heated at a temperature of 90° C., and reacted for 1 hour to obtain an N-phenylmaleamic acid solution;

[0025] 3) Add N-phenylmaleamic acid solution, 0.1 gram of hydroquinone, 0.1 gram of cuprous chloride and a supported catalyst into a dehydration reactor for dehydration and ring closure, the reaction temperature is 150°C, and the reaction time is 2 hours , remove the solvent under reduced pressure to obtain the crude product of N-phenylmaleimide;

[0026] 4) The obtained crude N-phenylmaleimide was recrystallized in 100 ml of ethanol to obtain N-phenylmaleimide with a yie...

Embodiment 3

[0028] 1) with 10% H 3 PO 4 The equal volume of the solution was impregnated with silica gel for 6 hours, then vacuum-dried and dried at high temperature to obtain a loaded catalyst; then 4 grams of loaded catalyst was packed into a stainless steel mesh and fixed on a stirrer;

[0029] 2) 9.3 grams of aniline and 9.8 grams of maleic anhydride were added to 70 milliliters of toluene for acylation, stirred, heated at a temperature of 80°C, and reacted for 2 hours to obtain an N-phenylmaleamic acid solution;

[0030] 3) Add N-phenylmaleamic acid solution, 0.3 g of cuprous chloride and a supported catalyst into a dehydration reactor for dehydration and ring closure, the reaction temperature is 150 ° C, the reaction time is 2 hours, and the solvent is removed under reduced pressure to obtain Crude N-phenylmaleimide;

[0031] 4) Recrystallize the crude N-phenylmaleimide obtained in 200 ml of cyclohexane to obtain N-phenylmaleimide with a yield of 87%;

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Abstract

The invention discloses a method for synthesizing N-benzyl maleimide from an immobilized supported acid catalyst and belongs to the synthesis technical field. The method comprises the following steps: soaking silica gel, a molecular sieve, aluminum trioxide and acidic resin or an active carbon carrier in an acid solution in equal volume, drying the mixture to obtain a supported catalyst and putting the supported catalyst into a stainless steel net; adding aniline and maleic anhydride into a benzene, toluene or xylene solvent and acidylating, stirring and heating the mixture to obtain the N-benzyl maleimide acid solution; then adding the N-benzyl maleimide acid solution, a polymerization inhibitor and the supported catalyst into a dehydration reactor for dehydration cyclization, reducing the pressure to remove the solvent and obtain the N-benzyl maleimide crude product, and recrystallizing in the solvent to obtain the N-benzyl maleimide. The invention has the advantages of high yield of N-benzyl maleimide, low content of waste acid, few production flows, low cost and little discharge of acid-containing waste water; moreover, as the catalyst is immobilized, the invention simplifies the replacement of the catalyst, reduces the mechanical abrasion of the catalyst and prolongs the service life of the catalyst.

Description

technical field [0001] The invention relates to a method for synthesizing N-phenylmaleimide with an immobilized supported acid catalyst, which belongs to the technical field of synthesis. Background technique [0002] N-phenylmaleimide (N-PMI for short) is a fine chemical product with a wide range of uses. It can be used as a vulcanizing agent for rubber to improve the strength and fatigue resistance of rubber; it can also be used as an environmentally friendly antifouling agent applied to ships, warships, underwater pipelines or fishing nets, which can effectively prevent the attachment and reproduction of harmful organisms. N-PMI is also an important organic synthesis intermediate for the synthesis of various fungicides, insecticides and pesticides. At present, N-phenylmaleimide is mainly used as a heat-resistant modifier for plastic products. As a heat-resistant modifier for ABS resin, N-PMI can not only greatly improve its heat resistance, but also Its processability, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D207/448B01J8/10
Inventor 史大昕郑靭李加荣徐习亮陈旭波张奇
Owner 广东光华化学厂有限公司
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