Production method of 4, 4-diaminodiphenyl ether

A technology of diaminodiphenyl ether and dinitrodiphenyl ether, which is applied in the field of hydrogenation synthesis of aromatic nitro compounds, can solve the problems of poor chromaticity, low yield, high energy consumption and the like, and achieves improved purity and improved Product focus, avoid the effect of darkening

Pending Publication Date: 2022-06-28
QINGDAO UNIV OF SCI & TECH
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  • Claims
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Problems solved by technology

[0003] On the other hand, there are two post-treatment processes in the existing hydrogenation preparation process. One is separation and distillation, and the obtained crude product is sublimated and crushed to obtain a granular product; the second is to add acid to the crude product to form a salt, decolorize, add Alkali adjusts the pH to neutral, and then recrystallizes, but the sublimation operation not only consumes a lot of energy, but also the prepared product is in the form of a block, which needs to be crushed again, and the method of adding acid to salt to adjust the alkali will produce a large amount of waste salt, and the above Both treatment methods have the problems of poor chromaticity, low purity and low yield, which do not conform to the current trend of green development

Method used

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  • Production method of 4, 4-diaminodiphenyl ether
  • Production method of 4, 4-diaminodiphenyl ether
  • Production method of 4, 4-diaminodiphenyl ether

Examples

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Embodiment 1

[0038] A production method of 4,4'-diaminodiphenyl ether, comprising the following steps:

[0039] ①Add 1kg 4,4'-dinitrodiphenyl ether, 5g catalyst Pt / C and 5kg methanol into the autoclave, stir and mix evenly, steam 500g methanol by low-temperature vacuuming, and replace the autoclave with nitrogen 3 times , and then fill the autoclave with hydrogen, the hydrogenation pressure is 0.4MPa, and react at 50 ° C for 6 hours to obtain a reaction solution;

[0040] ②Add 5g of sodium thiosulfate and 2.5kg of deionized water to the crystallizer, and use nitrogen to remove the air, and then filter the reaction solution obtained in step ① into the crystallizer for 10 hours of crystallization, and the crystallization temperature is 45 ℃, after the crystallization is completed, filter and wash the filter cake with deionized water to obtain 738 g of white granular product 4,4'-diaminodiphenyl ether, the product purity is 99.72%, and the particle size is about 60 mesh.

Embodiment 2

[0042] A production method of 4,4'-diaminodiphenyl ether, comprising the following steps:

[0043] ①Add 1kg of 4,4'-dinitrodiphenyl ether, 20g of catalyst Pd / C and 6kg of toluene into the autoclave, stir and mix evenly, steam 1kg of hydrogenation solvent by low-temperature vacuuming, and replace the autoclave with nitrogen 5 times, then fill the autoclave with hydrogen, the hydrogenation pressure is 1.2MPa, and react at 90 ° C for 4 hours to obtain a reaction solution;

[0044] ②Add 60g of zinc powder and 12kg of deoxidized ethylene glycol into the crystallizer, and use nitrogen to remove the air, then filter the reaction solution obtained in step ① and enter the crystallizer for crystallization for 15 hours. The crystallization temperature is 60°C, and the crystallization After completion, filter and wash the filter cake to obtain 742g of white granular product 4,4'-diaminodiphenyl ether, the yield is 96.48%, the product purity is 99.80%, and the particle size is about 150 me...

Embodiment 3

[0046] A production method of 4,4'-diaminodiphenyl ether, comprising the following steps:

[0047] ①Add 1kg 4,4'-dinitrodiphenyl ether, 10g catalyst Raney nickel and 5.4kg hydrogenation solvent N,N-dimethylacetamide into the autoclave, stir and mix evenly, and use low temperature vacuuming Steamed out 0.8kg of hydrogenation solvent, replaced the autoclave with nitrogen 4 times, then filled the autoclave with hydrogen, the hydrogenation pressure was 0.6MPa, and reacted at 65°C for 4.5 hours to obtain a reaction solution;

[0048] ②Add 21.6g of hydroxylamine hydrochloride and 4.32kg of deoxygenated chlorobenzene to the crystallizer, and use nitrogen to remove air, then filter the reaction solution obtained in step ① and enter the crystallizer for crystallization for 12 hours, and the crystallization temperature is 55°C, After the crystallization is completed, filter and wash the filter cake to obtain 750 g of white granular product 4,4'-diaminodiphenyl ether, the yield is 97.53%...

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Abstract

The invention discloses a production method of 4, 4 '-diaminodiphenyl ether, and relates to the technical field of aromatic nitro compound hydrogenation synthesis. According to the production method of the 4, 4 '-diaminodiphenyl ether, firstly, trace oxygen dissolved in the solvent is discharged by adopting a vacuum-pumping solvent evaporation method, and the problem that residual oxygen in the solvent cannot be replaced by only using nitrogen is solved, so that hydroxylamine benzene and azobenzene oxidation in the nitro hydrogenation process is inhibited, the darkening of the product color is avoided, and the product quality is improved. The impurity amount is increased; secondly, a specific inert poor solvent is adopted for crystallization, on one hand, side reaction of the amino compound and the solvent can be prevented, on the other hand, the inert solvent can crystallize and separate out the product from the reaction solvent, but the reaction impurities are reserved in the solvent, and therefore the purity of the product is improved; in addition, the addition of the reducing agent can prevent extremely trace oxygen free radicals in the solvent and nitrogen from oxidizing amino to influence the product color so as to ensure the color stability of the amino compound.

Description

technical field [0001] The invention relates to the technical field of hydrogenation synthesis of aromatic nitro compounds, in particular to a production method of 4,4'-diaminodiphenyl ether. Background technique [0002] 4,4'-Diaminodiphenyl ether is widely used in the fields of rubber, tires, plastics and fibers, but the amino group of this product is easily oxidized during the synthesis process, which makes the color of the product worse. This is due to the raw material 4,4' - The reaction mechanism of dinitrodiphenyl ether hydrogenation is divided into two types: one is nitro-nitroso-hydroxylamine-aniline; the other is azo-oxy-azo-hydroazo-aniline. For most aromatic nitro compounds, the hydrogenation route is the first, and the second is the side reaction route, which will cause the coupling of azo compounds to generate side reaction impurities. At the same time, it can also be known from the hydrogenation reaction process that the presence of oxygen will cause the oxid...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C213/02C07C217/90
CPCC07C213/02C07C217/90
Inventor 岳涛张智慧韩焕蓬王艳刘浩高维丹王灏
Owner QINGDAO UNIV OF SCI & TECH
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