Method for preparing 4, 4'-diphenyl ether dicarboxylic acid

A technology of diphenyl ether dicarboxylic acid and dimethyl diphenyl ether, which is applied in the field of preparing 4,4'-diphenyl ether dicarboxylic acid, can solve the problems of long reaction time, cumbersome operation, high cost, etc., and achieve less catalyst consumption , post-processing is simple, the effect of cost reduction

Active Publication Date: 2010-07-14
CHANGZHOU SUNLIGHT PHARMA +1
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  • Abstract
  • Description
  • Claims
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AI Technical Summary

Problems solved by technology

The disadvantage of this method is: the whole process needs three-step reaction, which takes a long time and costs high, and the intermediate p-nitrobenzonitrile is a highly toxic organic substance, and the yield is not high.
The disadvantage of this method is that the Friedel / Crafts acylation reaction needs to use expensive hafnium trifluoromethanesulfonate as a catalyst, and a large amount of LiClO must be added in the reaction. 4 , so it is difficult to produce industrially
The disadvantages of this method are: two-step oxidation reaction is required, the whole process takes a long time, the operation is cumbersome, the cost is high, and the yield is not high; moreover, the pyridine solvent used has a strong odor and toxicity, which pollutes the environment seriously and is not suitable for Industrial production
The disadvantages of this method are: ① high catalyst dosage: the molar ratio of cobalt salt and 4,4'-dimethyl diphenyl ether in the optimal catalyst dosage is 0.081, manganese salt and 4,4'-dimethyl diphenyl ether The molar ratio of diphenyl ether is 0.082, so the cost is higher
② Long reaction time: This method requires more than 30 hours of reaction time
③Complicated post-processing: acid-base treatment and activated carbon decolorization are required
The highest yield of this document is only 90.1%

Method used

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  • Method for preparing 4, 4'-diphenyl ether dicarboxylic acid
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  • Method for preparing 4, 4'-diphenyl ether dicarboxylic acid

Examples

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Embodiment 1）

[0024] This example is the preparation of 4,4'-diphenyl ether dicarboxylic acid by the normal pressure method (the reaction vessel is connected to the atmosphere during the reaction), which has the following steps:

[0025] ①Add 12g of the reactant 4,4'-dimethyldiphenyl ether, 1g of the catalyst cobalt acetate tetrahydrate, 0.75g of the catalyst manganese acetate, and 0.6g of the oxidation additive sodium bromide into a 100mL reaction flask, and then 50 g of organic acid propionic acid was added as a solvent.

[0026] ②By bubbling, quickly pass excess oxygen into the reaction device below the liquid level, and heat to 120°C to carry out the oxidation reaction of 4,4'-diphenyl ether dicarboxylic acid for 4 hours until a large amount of white solids are precipitated.

[0027] ③ Cool the material after the oxidation reaction to 20°C, then filter it with suction, then wash it twice with propionic acid, then wash it with water three times, and finally dry it in vacuum to obtain 14g...

Embodiment 2～ Embodiment 5）

[0029] The preparation method of each embodiment is basically the same as that of Example 1, and the differences are shown in Table 1.

[0030]

[0031]

Embodiment 6）

[0033] This example is the preparation of 4,4'-diphenyl ether dicarboxylic acid by the high-pressure method (the reaction vessel is in a closed state during the reaction), which has the following steps:

[0034] ①Add 6g of the reactant 4,4'-dimethyldiphenyl ether, 0.17g of the catalyst cobalt acetate tetrahydrate, 0.11g of the catalyst manganese acetate, and 0.32g of the oxidation additive sodium bromide into a 100mL autoclave, Then 30 g of the organic acid glacial acetic acid was added as a solvent.

[0035] ②Introduce excess oxygen into the autoclave and pressurize to 1.0MPa to generate 4,4'-diphenyl ether dicarboxylic acid oxidation reaction, while stirring and heating to 135°C, the pressure in the autoclave immediately drops rapidly, when the pressure When it drops to 0.5MPa, re-introduce oxygen and pressurize to 1.0MPa, repeat this cycle 2 to 4 times until the pressure in the autoclave is maintained for 1 hour and no longer drops.

[0036] ③ Cool the material after the o...

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Abstract

The invention discloses a method for preparing 4, 4'-diphenyl ether dicarboxylic acid, which comprises the following steps: 1, adding 4, 4'-dimethyl ether, catalysts, organic acids as solvents and bromide as oxide additives into a reaction device; 2, adopting a bubbling method for introducing oxygen under the liquid level of the solvent in the reaction device, and heating the mixture to 110 to 160 DEG C for oxidation reaction for 1 to 10 h, or adopting an intermittent method for pressing the oxygen into the reaction device in two to five times, pressurizing to 1.0 to 4.0 MPa, and simultaneously raising the temperature to 110 to 160 DEG C for oxidation reaction for 1 to 10 h; and 3, carrying out cooling, suction filtration, washing and drying on materials after the reaction. The method of the invention has few steps, short time and easy post treatment, and is applicable to industrial large-scale production, wherein the high-pressure oxidation method also has the advantages of little catalyst consumption, high yield and the like.

Description

technical field [0001] The invention relates to a method for preparing aromatic dicarboxylic acid, in particular to a method for preparing 4,4'-diphenyl ether dicarboxylic acid. Background technique [0002] 4,4'-Diphenyl ether dicarboxylic acid is an important polymer monomer, mainly used to prepare high-performance polybenzoxazole resins, polyarylate resins, high-performance fibers, insulating materials and thermoplastic liquid crystal polymers . At present, there are mainly the following methods for synthesizing 4,4'-diphenyl ether dicarboxylic acid: [0003] Chinese patent document CN1019484B (application number 89109210) discloses a method for synthesizing 4,4'-diphenyl ether dicarboxylic acid from p-nitrobenzoic acid. The method uses p-nitrobenzoic acid as a raw material, first reacts with phosphorus oxychloride and ammonia to produce p-nitrobenzyl cyanide, and then reacts with nitrite and carbonate to produce 4,4' -Dicyanodiphenyl ether, and finally hydrolyzed in a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C65/24C07C51/265
Inventor 胡国宜丁志伟缪文宏闵雪峰周国平丛雪丰游劲松兰静波
Owner CHANGZHOU SUNLIGHT PHARMA
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