Aftertreatment separation method of aromatic hydroxycarboxylic acid intermediate 3,6-dichloro-2-methoxybenzoic acid

A technology of methoxybenzoic acid and sodium methoxybenzoate, which is applied in the field of post-treatment separation of 3,6-dichloro-2-methoxybenzoic acid, can solve the problem of high production cost, low content of reaction products, Difficult to deal with and other problems, to achieve the effects of reduced emissions, good appearance, and reduced use of acid and alkali

Inactive Publication Date: 2016-11-23
陈云华
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the industry mostly uses this method for production, but its disadvantages are that the content of the reaction product is low and the amount of waste water is large, and this kind of high-salt, high-concentration organic waste water is difficult to treat, and the production cost of the enterprise is high.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 2

[0022] Put 232g of crude 3,6-dichloro-2-hydroxybenzoic acid whose content has been detected in a 500ml reactor, put in 192g of 50% liquid caustic soda, heat up to 70°C, add ethanol, start to add dimethyl sulfate dropwise, add auxiliary Catalyst 9.9g trifluoromethanesulfonic acid, reacted at a temperature of 70°C for 5 hours, added liquid alkali, then evaporated the organic solvent and filtered to obtain the intermediate 3,6-dichloro-2-methoxybenzoic acid sodium salt and Mother liquor, the mother liquor is reused as liquid caustic soda.

[0023] The solid intermediate 3,6-dichloro-2-methoxybenzoic acid sodium salt was dissolved in water, and activated carbon was added, wherein the weight ratio of 3,6-dichloro-2-methoxybenzoic acid sodium salt: activated carbon was 1: 0.04, Decolorize and stir at 90°C for 4 hours, filter to obtain the sodium salt of 3,6-dichloro-2-methoxybenzoic acid, and then analyze with acid to obtain 3,6-dichloro-2-methoxybenzoic acid. The product content i...

Embodiment 3

[0025] Put 232g of the crude product of 3,6-dichloro-2-hydroxybenzoic acid whose content has been detected in a 500ml reactor, put in 192g of 50% liquid caustic soda, heat up to 60°C, add methanol, start to drop dimethyl sulfate, add sulfuric acid Potassium dihydrogen 11.2g, react at a temperature of 60°C for 3 hours, add liquid alkali, then distill off the organic solvent and filter to obtain the intermediate 3,6-dichloro-2-methoxybenzoic acid sodium salt and mother liquor, mother liquor Utilize and reuse as liquid caustic soda.

[0026] The solid intermediate 3,6-dichloro-2-methoxybenzoic acid sodium salt was dissolved in water, and activated carbon was added, wherein the weight ratio of 3,6-dichloro-2-methoxybenzoic acid sodium salt: activated carbon was 1: 0.04, Decolorize and stir at 80°C for 2 hours, filter to obtain the sodium salt of 3,6-dichloro-2-methoxybenzoic acid, and analyze with acid to obtain 3,6-dichloro-2-methoxybenzoic acid. The product content is 99.4%, an...

Embodiment 4

[0028] Put 232g of crude 3,6-dichloro-2-hydroxybenzoic acid whose content has been detected in a 500ml reactor, put in 192g of 50% liquid caustic soda, heat up to 80°C, add xylene, start to drop dimethyl sulfate, add Sodium dodecylbenzenesulfonate 11.6g, react at 80°C for 6 hours, add liquid alkali, then evaporate the organic solvent and filter to obtain the intermediate 3,6-dichloro-2-methoxybenzoic acid sodium Salt and mother liquor, the mother liquor is reused as liquid caustic soda.

[0029] The solid intermediate 3,6-dichloro-2-methoxybenzoic acid sodium salt was dissolved in water, and activated carbon was added, wherein the weight ratio of 3,6-dichloro-2-methoxybenzoic acid sodium salt: activated carbon was 1: 0.06, Decolorize and stir at 80°C for 3 hours, filter to obtain the sodium salt of 3,6-dichloro-2-methoxybenzoic acid, and then analyze with acid to obtain 3,6-dichloro-2-methoxybenzoic acid. The product content is 99.3%, and the waste water volume is 1050ml.

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Abstract

The invention belongs to the technical field of chemical aftertreatment green separation and particularly relates to an aftertreatment separation method of 3,6-dichloro-2-methoxybenzoic acid. The aftertreatment separation method of an aromatic hydroxycarboxylic acid intermediate 3,6-dichloro-2-methoxybenzoic acid comprises the following steps: 1) adding a crude product of 3,6-dichloro-2-hydroxybenzoic acid into caustic soda liquid; heating to 50-80 DEG C; adding an organic solvent, and dropwise adding dimethyl sulfate; and after 3-6 hours of reaction, steaming to remove the organic solvent to obtain an intermediate 3,6-dichloro-2-sodium methoxybenzoate; and 2) performing decoloration and acid separation on the intermediate obtained in the step 1). The content of the obtained product is high, a small amount of wastewater is generated, and the wastewater can be recycled and causes little environmental pollution.

Description

technical field [0001] The invention belongs to the field of chemical post-treatment green separation technology, in particular to a post-treatment separation method of 3,6-dichloro-2-methoxybenzoic acid. Background technique [0002] Throughout the production process of 3,6-dichloro-2-methoxybenzoic acid, 2,5-dichloroaniline is hydrolyzed by sulfuric acid, sodium nitrite, and diazotization, and the intermediate 2,5-dichlorophenol is isolated . 2,5-dichlorophenol is then reacted with refined potassium carbonate, reacted with carbon dioxide by Copper-Schmidt carboxylation, and then O-alkylated with dimethyl sulfate to obtain 3,6-dichloro- 2-Methoxybenzoic acid. At present, the industry mostly uses this method for production, but its disadvantages are that the content of the reaction product is low and the amount of waste water is large, and this kind of high-salt, high-concentration organic waste water is difficult to treat, and the production cost of the enterprise is high...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/347C07C65/21
CPCC07C51/347C07C65/21
Inventor 陈云华张端友周海蓉邹立昌陈振民周志明
Owner 陈云华
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