Process for preparing 3,4-diaminodiphenyl ether

A technology of diaminodiphenyl ether and nitrodiphenyl ether, which is applied to the preparation of amino hydroxyl compounds, the preparation of organic compounds, chemical instruments and methods, etc., can solve the problems of post-processing difficulties and unsafety, and achieve the goal of overcoming unsafe Factors, mild conditions, good product purity

Inactive Publication Date: 2004-03-31
SHANGHAI CHEM REAGENT RES INST
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The technical problem that the present invention solves is to provide a kind of preparation method of 3,4'-diaminodiphenyl ether, to overcome the unsafe factors existing in the high-pressure hydrogenation method in the prior art, and the post-processing difficulties existing in the high-vacuum distillation insufficient

Method used

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  • Process for preparing 3,4-diaminodiphenyl ether
  • Process for preparing 3,4-diaminodiphenyl ether
  • Process for preparing 3,4-diaminodiphenyl ether

Examples

Experimental program
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Effect test

Embodiment 1

[0024] Synthesis of 3,4'-diaminodiphenyl ether from 3-amino-4'-nitrodiphenyl ether:

[0025] Add 750ml of industrial ethanol to a 2000ml four-necked flask equipped with a reflux condenser, agitator, and a thermometer, and add 230g (1mol) of 3-amino-4'-nitrodiphenyl ether, 20g of activated carbon, and 0.2g of FeCl under stirring. 3 ·6H 2 O, introduce nitrogen, under nitrogen atmosphere, heat to 75±5°C, slowly drop in 155g 80% hydrazine hydrate (2.5mol) within 1 hour, keep reflux for 3 hours, cool to room temperature, filter, wash with 50ml industrial ethanol The filter residue was combined with ethanol, and 1000ml of water was added under stirring, and white crystals were precipitated. Filter, wash with water, and dry to obtain 186g of 3,4'-diaminodiphenyl ether with a yield of 93%, a purity of ≥99% (HPLC), and a melting point of 74.3-75.6°C (value in JP 61,221,159: 74-76°C).

Embodiment 2

[0027] Synthesis of 3,4'-diaminodiphenyl ether from 3,4'-dinitrodiphenyl ether:

[0028] Add 75ml of industrial ethanol in a 250ml four-neck flask equipped with a reflux condenser, agitator, and a thermometer, and add 26g (0.1mol) of 3,4'-dinitrodiphenyl ether, 2g of activated carbon, and 20mg of FeCl under stirring. 3 ·6H 2 O, introduce nitrogen, under nitrogen atmosphere, heat to 75±5°C under stirring, slowly drop in 31g of 80% hydrazine hydrate (0.5mol) within 1 hour, reflux for 2.5 hours after dropping, cool to room temperature, filter, use Wash the filter residue with 10ml of industrial ethanol, combine the ethanol, add 100ml of water under stirring, and precipitate white crystals. Filter, wash with water, and dry to obtain 17.8g of 3,4'-diaminodiphenyl ether with a yield of 89%, a purity of ≥99% (HPLC), and a melting point of 74.0-75.3°C.

Embodiment 3

[0030] Add 750ml of industrial ethanol to a 2000ml four-neck flask equipped with a reflux condenser, agitator, and a thermometer, and add 230g (1mol) of 3-amino-4'-nitrodiphenyl ether, 20g of activated carbon, and 0.2g of FeCl under stirring. 3 ·6H 2 O, introduce nitrogen, under nitrogen atmosphere, heat to 60±5°C, slowly drop in 155g 80% hydrazine hydrate (2.5mol) within 1 hour, reflux for 3 hours after dropping, cool to room temperature, filter, use 50ml industrial The filter residue was washed with ethanol, combined with ethanol, and 900ml of water was added under stirring to precipitate white crystals. Filter, wash with water, and dry to obtain 180 g of 3,4'-diaminodiphenyl ether with a yield of 90%, a purity of ≥99% (HPLC), and a melting point of 74.3-75.6°C.

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Abstract

A process of preparing 3ú¼4'-diamino diphenyl ether. It comprises: taking nitrodiphenyl ether as the raw material, hydrazine hydrate as the reducing agent, reducing in the presence of a catalyst, obtaining 3ú¼4'-diamino diphenyl ether at a low pressure. The invention overcomes unsafe factors in the method of high-pressure hydrogenation, avoid the step of highpressure distillation, and has mild reactive conditions. The product has good purity. So the invention is suitable for industrial production.

Description

technical field [0001] The present invention relates to a kind of preparation method of polyimide monomer 3,4'-diaminodiphenyl ether. Background technique [0002] 3,4'-diaminodiphenyl ether is an important chemical raw material, especially as a monomer for the preparation of polyimide. Its structural formula is: [0003] [0004] Japanese Patent Laid-Open No. 61-221159 discloses a method for obtaining 3-amino-4'-nitrodiphenyl ether by condensation of m-aminophenol and p-chloronitrobenzene. The crude product of 3,4'-diaminodiphenyl ether was obtained by hydrogen reduction, and then distilled under high vacuum to obtain 3,4'-diaminodiphenyl ether. [0005] JP-A-54-88288 discloses a method of condensing m-nitrophenol and p-chloronitrobenzene to obtain 3,4'-dinitrodiphenyl ether. First, high-pressure hydrogenation reduction under the catalysis of Pd / C obtains 3, The crude product of 4'-diaminodiphenyl ether is then distilled with high vacuum to obtain 3,4'-diaminodiphenyl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C213/02C07C217/80
Inventor 廖本仁袁振文刘志平虞鑫海
Owner SHANGHAI CHEM REAGENT RES INST
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