Preparation of N-phenyl maleimide

A technology of maleimide and phenyl, which is applied in the field of preparation of N-phenylmaleimide, can solve the problems of long preparation cycle, high energy consumption, high cost, etc., achieve stable product quality, reduce three wastes, The effect of reaction time reduction

Inactive Publication Date: 2009-06-24
SHANGHAI HUAYI GRP CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The technical problem that the present invention solves is to provide a kind of preparation method of N-phenylmaleimide, to overcome the low yield in the prior art, high cost, long preparation period, the shortcoming of big energy consumption

Method used

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  • Preparation of N-phenyl maleimide
  • Preparation of N-phenyl maleimide
  • Preparation of N-phenyl maleimide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Add respectively 100ml dimethylbenzene, 0.2g 2,6-di-tert-butyl p-cresol, mixed dehydration catalyst 4g (concentrated sulfuric acid and hydrogensulfate The mass ratio of sodium is 1.0:1.0, g / g). Heat up to reflux under stirring, the temperature is 140°C, drop into ① the mixed solution containing 58.8g (0.6mol) maleic anhydride-100ml xylene-10ml DMF through the dropping funnel within 0.5 hours, ② 46.5g (0.5mol) Aniline was continued to reflux for 1 hour, and 9ml of water was separated. The reaction solution was cooled to 60°C, 55ml of 15wt% sodium carbonate solution was slowly added, stirred for 5 minutes, left to stand, the organic phase was separated, the solvent was evaporated under reduced pressure, and 174ml of the solvent was recovered to obtain the yellow solid product N-phenylmaleimide Amine 77.9g, yield 90%, purity: 98.7% (HPLC). Melting point: 88.6-90.1°C.

Embodiment 2

[0026] Add respectively 100ml toluene, 0.2g pyrocatechol, and 3g of mixed dehydration catalyst (the mass ratio of concentrated sulfuric acid and sodium dihydrogen phosphate is 5.0 in the reactor with heating, thermometer, dropping funnel, reflux water separation condenser tube: 1.0, g / g). Heat up to reflux under stirring, the temperature is 110°C, drop into ① a mixture containing 56.35g (0.575mol) maleic anhydride-100ml toluene-8ml DMF, ② 46.5g (0.5mol) aniline through the dropping funnel within 0.5 hours , continue the reflux reaction for 2 hours, and separate 9ml of water. The reaction solution was cooled to 60°C, 75ml of 10wt% sodium carbonate solution was slowly added, stirred for 5 minutes, left to stand, the organic phase was separated, the solvent was evaporated under reduced pressure, and 162ml of solvent was recovered to obtain the yellow solid product N-phenylmaleimide Amine 79.2g, yield 91.5%, purity 99.0% (HPLC). Melting point: 89.2-90.1°C.

Embodiment 3

[0028] Add respectively 100ml toluene, 0.2g hydroquinone, mixed dehydration catalyst 5g (the mass ratio of concentrated sulfuric acid and p-toluenesulfonic acid is 1.5:1.0, g / g). Heat up to reflux with stirring, the temperature is 110°C, drop into ① a mixture containing 53.9g (0.55mol) maleic anhydride-100ml xylene-7.5ml DMF, ② 46.5g through the dropping funnel within 1.0 hour under reflux (0.5mol) aniline, continued to reflux for 2.5 hours, and separated 9ml of water. The reaction solution was cooled to 50°C, 100ml of 8wt% sodium carbonate solution was slowly added, stirred for 5 minutes, left to stand, the organic phase was separated, the solvent was evaporated under reduced pressure, and 158ml of the solvent was recovered to obtain the yellow solid product N-phenylmaleimide Amine 79.5g, yield 92%, purity: 98.9% (HPLC). Melting point: 88.7-90.3°C.

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Abstract

The invention discloses a method for preparing N-benzyl maleimide which adopts maleic anhydride and aniline as raw materials to take imidation reaction in benzene reaction solvent in the presence of an inhibitor and a mixed dehydration catalyst to obtain the target product of the invention. The purity of the N-benzyl maleimide prepared by the one-step method of the invention reaches more than 98.5 percent, and the yield is 90-92 percent. Compared with the prior art, the method has the advantages of less reaction time, short period and safe and convenient operation. A post-processing method of directly drying out the solvent and recycling the solvent is adopted, so that the yield is improved, three wastes are reduced, the operational environment is improved and the quality of products is stable. The method is applied to the large-scale industrial production.

Description

technical field [0001] The invention relates to a preparation method of N-phenylmaleimide. Background technique [0002] N-phenylmaleimide is an important organic compound, which can be widely used in antifouling coatings and heat-resistant plastics. As a heat-resistant modifier, N-phenylmaleimide can also partially replace engineering plastics, and can be added to ABS resin to produce super heat-resistant ABS resin, making the heat-resistant temperature of ABS resin reach 125-130°C. Its structural formula is as follows: [0003] [0004] In the prior art, the method for preparing N-phenylmaleimide is mainly carried out with maleic anhydride and aniline, and its reaction process is: [0005] [0006] Shandong Chemical Industry, 2000, volume 29, third issue, pages 13-14 "Research on the preparation of N-phenylmaleimide", reported a two-step method for preparing N-phenylmaleimide, at 55-65 ° C Maleic anhydride is reacted with aniline under certain conditions, and afte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D207/448
Inventor 揭元萍袁振文廖本仁
Owner SHANGHAI HUAYI GRP CO
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