Synthesis method of aminophenol

A technology of aminophenol and synthesis method, which is applied in the preparation of amino hydroxy compounds, chemical instruments and methods, preparation of organic compounds, etc., can solve the problems of increased post-processing difficulty, large amount of three wastes, poor process safety, etc., and achieves the difficulty of three-waste treatment. Small, high yield and purity, simple post-processing

Pending Publication Date: 2020-06-19
JIANGSU YANGNONG CHEM GROUP +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the yield of this method is low, and the reducing agent sodium hydrosulfite used has poor stability and low safety. At the same time, sulfate waste water is produced, which increases the difficulty of post-treatment.
[0006] At present, there are few reports on the preparation of 2,6-dichloro-4-aminophenol by reducing 2,6-dichloro-4-nitrophenol with hydrogen at home and abroad, mainly because the product is unstable, the reaction selectivity is poor, and the technology is difficult.
Using hydrazine hydrate, hydrosulfite, etc. as reducing agents, the process safety is poor and the amount of three wastes is large
[0007] Therefore, in view of the problems existing in the above process, it is urgent to develop a stable hydrogenation synthesis technology to prepare aminophenol, so as to solve the problems of low yield, poor safety of reducing agent and difficult wastewater treatment in the prior art.

Method used

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  • Synthesis method of aminophenol
  • Synthesis method of aminophenol
  • Synthesis method of aminophenol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0078] The present embodiment provides a kind of synthetic method of 2,6-dichloro-4-aminophenol, and described method comprises the steps:

[0079] (1) Put 2,6-dichloro-4-nitrophenol and tetrahydrofuran into the autoclave, wherein the mass ratio of 2,6-dichloro-4-nitrophenol and tetrahydrofuran is 0.01:1, Rh / Al 2 o 3 Supported catalyst and auxiliary agent acetic acid, wherein the mass ratio of catalyst to 2,6-dichloro-4-nitrophenol is 0.01:1, and the molar ratio of auxiliary agent acetic acid to 2,6-dichloro-4-nitrophenol is 2:1; carry out the hydrogenation reaction at a reaction temperature of 30°C and a pressure of 0.2MPa for a reaction time of 10 hours. After the reaction is completed, the temperature is lowered to release the pressure, and the reaction liquid and the catalyst are separated, and the catalyst is returned to the hydrogenation reaction for use;

[0080] (2) The reaction solution after separation is subjected to negative pressure distillation under an absolute...

Embodiment 2

[0083] The present embodiment provides a kind of synthetic method of 2,6-dichloro-4-aminophenol, and described method comprises the steps:

[0084](1) Put 2,6-dichloro-4-nitrophenol and ethanol into the autoclave, wherein the mass ratio of 2,6-dichloro-4-nitrophenol to ethanol is 0.8:1, Raney nickel Catalyst and auxiliary agent sulfuric acid, wherein the mass ratio of Raney nickel catalyst to 2,6-dichloro-4-nitrophenol is 0.1:1, and the molar ratio of auxiliary agent sulfuric acid to 2,6-dichloro-4-nitrophenol The ratio is 0.01:1; the hydrogenation reaction is carried out at a reaction temperature of 40°C and a pressure of 0.5 MPa, and the reaction time is 5 hours. After the reaction is completed, the temperature is lowered and the pressure is released, and the reaction liquid and the catalyst are separated, and the catalyst is returned to the hydrogenation reaction for mechanical application;

[0085] (2) The reaction solution after separation is carried out negative pressure...

Embodiment 3

[0088] The present embodiment provides a kind of synthetic method of 2,6-dichloro-4-aminophenol, and described method comprises the steps:

[0089] (1) Put 2,6-dichloro-4-nitrophenol and methanol into the autoclave, wherein the mass ratio of 2,6-dichloro-4-nitrophenol to methanol is 0.3:1, Pd / C Supported catalyst and auxiliary agent hydrochloric acid, wherein the mass ratio of catalyst to 2,6-dichloro-4-nitrophenol is 0.05:1, and the molar ratio of auxiliary agent hydrochloric acid to 2,6-dichloro-4-nitrophenol is 0.1:1; carry out the hydrogenation reaction at a reaction temperature of 50°C and a pressure of 1 MPa, and the reaction time is 2 hours. After the reaction is completed, the temperature is lowered and the pressure is released, and the reaction liquid and the catalyst are separated, and the catalyst is returned to the hydrogenation reaction for mechanical application;

[0090] (2) The reaction solution after separation is carried out under the absolute pressure 5kPa t...

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Abstract

The invention provides a synthesis method of aminophenol. According to the method, by reacting nitrophenol with hydrogen under the conditions of an auxiliary agent and a solvent, an aminophenol product with high selectivity and yield can be prepared, the auxiliary agent can well control the reaction depth of nitrophenol and hydrogen, thereby inhibiting the side reaction, enhancing the purity of the final product, overcoming the problems of poor selectivity and high three-waste amount in the common hydrazine hydrate, sodium hydrosulfite and other reducing agents in the prior art, and having higher industrial application value.

Description

technical field [0001] The invention relates to the technical field of organic chemical industry, in particular to a synthesis method of aminophenol. Background technique [0002] Chlorfluazuron (CAS: 71422-67-8) is a benzoylurea-type insecticide with high efficiency and low toxicity. , is a new insect growth regulator. It has high insecticidal activity. At the same time, the drug has low toxicity to humans and animals, has little impact on the environment, and is safe to natural enemies that prey on pests. It is a promising pesticide product with high efficiency, low toxicity, and good environmental compatibility. . [0003] The synthesis of chlorfluazuron uses 2,6-dichloro-4-aminophenol and 2,3-dichloro-5-trifluoromethylpyridine as raw materials to obtain 3,5-dichloro-4-(3 -Chloro-5-trifluoromethyl-2-pyridyloxy)aniline, 2,6-difluorobenzamide and solid phosgene react to give 2,6-difluorobenzoyl isocyanate, 3,5-dichloro -4-(3-Chloro-5-trifluoromethyl-2-pyridyloxy)aniline...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C213/02C07C213/10C07C215/76
CPCC07C213/02C07C213/10C07C215/76
Inventor 王根林聂庆超丁克鸿徐林王刚汪洋殷剑虎陈耀坤李良善何成义
Owner JIANGSU YANGNONG CHEM GROUP
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