Production method of 3,5-dimethylbenzoic acid

A technology of dimethylbenzoic acid and production method, which is applied in 3 fields, can solve problems such as large fluctuations in oxidation temperature, low conversion rate of mesitylene, troublesome operation, etc., to achieve improved product yield, complete oxidation, and improved conversion rate Effect

Active Publication Date: 2014-03-26
安徽泰达新材料股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since there is no solvent to participate in the oxidation reaction, the conversion rate of mesitylene is low, the oxidation temperature fluctuates greatly, and the operation is troublesome

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] a. Mix mesitylene, acetic acid solvent, cobalt acetate catalyst, initiator 40% industrial acetaldehyde, keep the temperature at 40°C, wherein the mass ratio of acetic acid to mesitylene is 1:1, mesitylene, cobalt acetate, ethyl The mass ratio of the three aldehydes is 1:0.1×10 -3 : 1×10 -2 .

[0020] b. Then pass the compressed air into the oxidation tower containing the above mixture to carry out the oxidation reaction, wherein the oxidation temperature is 100°C, the pressure is 0.1MPa, and the compressed air flow rate is 200m 3 / h, when the oxygen content in the oxidation reaction tail gas reaches 19%, the oxidation ends.

[0021] c. Then use 0.1MPa pressure to press the material after the oxidation reaction into the crystallization tank to stir, cool and crystallize, and separate the solid and liquid after the crystallization is complete, wherein the filter cake is the crude product 3,5-dimethylbenzoic acid, and the filtrate is dilute acetic acid and A small amoun...

Embodiment 2

[0024] a. Mix mesitylene, acetic acid solvent, cobalt acetate catalyst, initiator 40% industrial acetaldehyde, keep the temperature at 80°C, wherein the mass ratio of acetic acid to mesitylene is 5:1, mesitylene, cobalt acetate, ethyl The mass ratio of the three aldehydes is 1:20×10 -3 : 10×10 -2 .

[0025] b. Then pass the compressed air into the oxidation tower containing the above mixture to carry out the oxidation reaction, wherein the oxidation temperature is 150°C, the pressure is 0.5MPa, and the compressed air flow rate is 200m 3 / h, when the oxygen content in the oxidation reaction tail gas reaches 21%, the oxidation ends.

[0026] c. Then use 0.1MPa pressure to press the material after the oxidation reaction into the crystallization tank to stir, cool and crystallize, and separate the solid and liquid after the crystallization is complete, wherein the filter cake is the crude product 3,5-dimethylbenzoic acid, and the filtrate is dilute acetic acid and A small amoun...

Embodiment 3

[0029] a. Mix mesitylene, acetic acid solvent, cobalt acetate catalyst, initiator 40% industrial acetaldehyde, keep the temperature at 60°C, wherein the mass ratio of acetic acid to mesitylene is 3:1, mesitylene, cobalt acetate, ethyl The mass ratio of the three aldehydes is 1:10×10 -3 : 6×10 -2 .

[0030] b. Then pass the compressed air into the oxidation tower containing the above mixture to carry out the oxidation reaction, wherein the oxidation temperature is 120°C, the pressure is 0.3MPa, and the compressed air flow rate is 150m 3 / h, when the oxygen content in the oxidation reaction tail gas reaches 20%, the oxidation ends.

[0031] c. Then use 0.1MPa pressure to press the material after the oxidation reaction into the crystallization tank to stir, cool and crystallize, and separate the solid and liquid after the crystallization is complete, wherein the filter cake is the crude product 3,5-dimethylbenzoic acid, and the filtrate is dilute acetic acid and A small amount...

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PUM

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Abstract

The invention provides a production method of 3,5-dimethylbenzoic acid. The technical scheme adopted by the invention comprises the following steps: a, mixing mesitylene, an acetic acid solvent and a cobalt acetate catalyst; b, then introducing compressed air into an oxidation container containing the mixture for oxidation reaction; c, subsequently, crystallizing and filtering the material after oxidation reaction; and d, finally, rectifying and purifying filter residue to obtain 3,5-dimethylbenzoic acid. According to the treatment method in the invention, reaction heat which is generated when mesitylene is subjected to oxidation reaction is continuously evaporated and condensed by depending on the acetic acid solvent so as to be taken away, thus the temperature is well controlled, and reaction is mild; and oxygen absorption amount can be improved by acetic acid so that oxidation is more complete, thereby improving the yield of the product. Thus, by using the production method in the invention, the conversion rate of mesitylene is improved to 90%.

Description

technical field [0001] The invention relates to the field of organic chemistry, in particular to a production method of 3,5-dimethylbenzoic acid. Background technique [0002] 3,5-Dimethylbenzoic acid is the main intermediate in organic synthesis, which can be used to produce tebufenozide pesticide, synthetic prostaglandin, synthetic flame retardant, plasticizer, etc. Domestically, a method for producing 3,5-dimethylbenzoic acid was disclosed on August 14, 2002 (public patent No. CN1363546). This method uses mesitylene as a raw material without using a solvent for preparation. Because there is no solvent to participate in the oxidation reaction, the conversion rate of mesitylene is low, the oxidation temperature fluctuates greatly, and the operation is troublesome. Contents of the invention [0003] The main purpose of the present invention is to provide a kind of 3, the production method of 5-dimethylbenzoic acid, and this method oxidation temperature is stable, and conv...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C07C63/04C07C51/265
Inventor柯伯成柯伯留汪永辉其他发明人请求不公开姓名
Owner安徽泰达新材料股份有限公司