Improved alkylation process for producing Mediben

A technology of alkylation and dicamba, applied in the field of herbicides, can solve problems such as toxicity, poor safety, and high toxicity of dimethyl sulfate, and achieve the effects of increasing yield, reducing environmental toxicity, and loose and easy-to-control production conditions

Inactive Publication Date: 2006-09-13
江苏生花农药有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because dimethyl sulfate is insoluble in water, the productive rate of this reaction can only reach 80%, in addition, because dimethyl sulfate toxicity is bigger, directly adds dimethyl su

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0008] Example 1, the improved alkylation process in the production of dicamba, 3,6-dichlorosalicylic acid was dissolved in toluene solvent, dimethyl sulfate was added dropwise, and reacted at a temperature of 90-100°C for 4-6 hours , add a sodium hydroxide solution with a concentration of 20-30% to the intermediate after the solvent is evaporated, and reflux and stir for 2-4 hours in a boiling state at 100°C to obtain dicamba sodium salt, 3,6-dichlorosalicyl The molar ratio of acid to dimethyl sulfate and sodium hydroxide is 1:2.0:2.0.

Example Embodiment

[0009] Example 2, the improved alkylation process in the production of dicamba, 3,6-dichlorosalicylic acid was dissolved in acetone solvent and dimethyl sulfate was added dropwise, and reacted at a temperature of 40-50°C for 4-6 hours , add a sodium hydroxide solution with a concentration of 20-30% to the intermediate after the solvent is evaporated, and reflux and stir for 2-4 hours in a boiling state at 100°C to obtain dicamba sodium salt, 3,6-dichlorosalicyl The molar ratio of acid to dimethyl sulfate and sodium hydroxide is 1:2.1:2.1.

Example Embodiment

[0010] Example 3, the improved alkylation process in the production of dicamba, 3,6-dichlorosalicylic acid was dissolved in tetrahydrofuran solvent and dimethyl sulfate was added dropwise, and reacted at a temperature of 40-50°C for 4-6 hours , add a sodium hydroxide solution with a concentration of 20-30% to the intermediate after the solvent is evaporated, and reflux and stir for 2-4 hours in a boiling state at 100°C to obtain dicamba sodium salt, 3,6-dichlorosalicyl The molar ratio of acid to dimethyl sulfate and sodium hydroxide is 1:2.2:2.2.

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Abstract

An improved alkylating process for preparing dicamba includes such steps as dissolving 3,6-dichloro salicylic acid in organic solvent, dropping dimethyl sulfate, reaction, removing solvent by evaporating, and reacting on the solution of sodium hydroxide to obtain the sadium salt of dicamba.

Description

technical field [0001] The invention relates to a production method of a herbicide, in particular to an alkylation process in the production of dicamba. Background technique [0002] In the entire production process of the herbicide dicamba, 2,5-dichloroaniline is diazotized by sulfuric acid and sodium nitrite to obtain the intermediate 2,5-dichlorophenol, which is then reacted with potassium hydroxide Converted to 2,5-dichlorophenate potassium, 2,5-dichlorophenate potassium is carboxylated by carbon dioxide and potassium carbonate, and another intermediate 3,6-dichlorosalicylic acid, 3,6-dichlorohydrin is separated Dicamba sodium salt is obtained by adding dimethyl sulfate dropwise to sodium hydroxide aqueous solution and refluxing at 100-104°C to obtain dicamba sodium salt and then acidifying to obtain the finished dicamba. Because dimethyl sulfate is insoluble in water, the productive rate of this reaction can only reach 80%, in addition, because dimethyl sulfate toxicit...

Claims

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Application Information

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IPC IPC(8): C07C63/06C07C51/00
Inventor 蒋荣义刘宝川杨晓伦
Owner 江苏生花农药有限公司
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