Synthesis method of pinoxaden intermediate (2, 6-diethyl-4-methyl)phenylacetic acid

A technology of pinoxaden and a synthesis method, applied in the field of synthesis of pinoxaden intermediate phenylacetic acid, can solve the problems of limited industrial application, high cost, expensive palladium catalyst, etc., and achieve high industrial value and yield High, the effect of avoiding the use of palladium catalysts

Inactive Publication Date: 2019-04-19
JIANGSU FLAG CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] In summary, most routes use palladium catalyst coupling to synthesize intermediate 2, but the palladium catalyst is expensive and the cost is high, which limits its industrial application

Method used

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  • Synthesis method of pinoxaden intermediate (2, 6-diethyl-4-methyl)phenylacetic acid
  • Synthesis method of pinoxaden intermediate (2, 6-diethyl-4-methyl)phenylacetic acid
  • Synthesis method of pinoxaden intermediate (2, 6-diethyl-4-methyl)phenylacetic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Step 1: In a 250mL four-neck flask, add 65mL of 45% hydrobromic acid solution (0.36mol), slowly add 16.33g of 2,6-diethyl-4-methylaniline (molecular weight 163.3, 0.1mol) dropwise, drop Bi raised the temperature to 80°C and stirred for half an hour and then lowered to -10°C. Control the temperature at -10°C to -5°C, and slowly add sodium nitrite solution (8g of sodium nitrite dissolved in 35mL of water, 0.116mol) dropwise, and the dripping is completed in about 1 hour. After dropping, keep stirring at -10°C to -5°C for half an hour to form a diazonium salt solution. Add 13.9g of ferrous sulfate heptahydrate (molecular weight: 278, 0.05mol) and 65mL of 45% hydrobromic acid solution (0.36mol) into another four-neck flask, and heat to 80°C. The above diazonium salt solution was slowly added dropwise to another four-necked flask, and the drop was completed in about 1 hour. After the drop was completed, the temperature was kept stirring at 80° C. for 1 hour. Cool down to r...

Embodiment 2

[0044] Example 2: 2-bromoethanol example

[0045] Step 1: In a 250mL four-neck flask, add 45mL of 45% hydrobromic acid solution (0.25mol), slowly add 16.33g of 2,6-diethyl-4-methylaniline (molecular weight 163.3, 0.1mol) dropwise, drop Bi raised the temperature to 80°C and stirred for half an hour and then lowered to -10°C. Control the temperature at -10°C to -5°C, and slowly add sodium nitrite solution (8g of sodium nitrite dissolved in 35mL of water, 0.116mol) dropwise, and the dripping is completed in about 1 hour. After dropping, keep stirring at -10°C to -5°C for half an hour to form a diazonium salt solution. Add 11.1 g of ferrous sulfate heptahydrate (molecular weight: 278, 0.04 mol) and 54 mL of 45% hydrobromic acid solution (0.30 mol) into another four-neck flask, and heat to 80°C. The above diazonium salt solution was slowly added dropwise to another four-necked flask, and the drop was completed in about 1 hour. After the drop was completed, the temperature was kep...

Embodiment 3

[0048] Example 3: Example of sec-butyllithium

[0049] Step 1: In a 250mL four-neck flask, add 72mL of 45% hydrobromic acid solution (0.40mol), slowly add 16.33g of 2,6-diethyl-4-methylaniline (molecular weight 163.3, 0.1mol) dropwise, drop Bi raised the temperature to 80°C and stirred for half an hour and then lowered to -10°C. Control the temperature at -10°C to -5°C, and slowly add sodium nitrite solution (8g of sodium nitrite dissolved in 35mL of water, 0.116mol) dropwise, and the dripping is completed in about 1 hour. After dropping, keep stirring at -10°C to -5°C for half an hour to form a diazonium salt solution. Add 27.8g of ferrous sulfate heptahydrate (molecular weight: 278, 0.1mol) and 90mL of 45% hydrobromic acid solution (0.50mol) into another four-neck flask, and heat to 80°C. The above diazonium salt solution was slowly added dropwise to another four-necked flask, and the drop was completed in about 1 hour. After the drop was completed, the temperature was kep...

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Abstract

The invention relates to the field of organic synthesis, in particular to a synthesis method of a pinoxaden intermediate (2, 6-diethyl-4-methyl)phenylacetic acid. The method includes: letting 2, 6-diethyl-4-methylaniline, hydrobromic acid and sodium nitrite form a diazo salt; reacting the diazo salt with ferrous sulfate and hydrobromic acid to generate 2, 6-diethyl-4-methylbromobenzene; letting 2,6-diethyl-4-methylbromobenzene and alkyl lithium generate a lithium salt, and then reacting the obtained lithium salt with ethylene oxide or 2-halogenated ethanol to obtain (2, 6-diethyl-4-methyl)phenethyl alcohol; under the catalysis of TEMPO, adding NaClO and NaClO2 successively into the (2, 6-diethyl-4-methyl)phenethyl alcohol and performing oxidization so as to obtain (2, 6-diethyl-4-methyl)phenylacetic acid. The synthesis method provided by the invention has high yield, avoids the use of expensive palladium catalyst, reduces the cost, and has high industrial value.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method for synthesizing pinoxaden intermediate (2,6-diethyl-4-methyl)phenylacetic acid. Background technique [0002] The herbicide pinoxaden is a new phenylpyrazoline herbicide successfully developed by Syngenta through experiments. It is mainly called Pinoxaden in the international market. At present, the commodity circulating in the domestic market is mainly Aixiu. It mainly prevents the synthesis of fatty acids, so that the meristem effect of the plant disappears, resulting in the death of the plant. Pinoxaden is easily soluble in water, difficult to photolysis, easy to degrade and adsorb in soil, but difficult to leaching and volatilization. The toxicity of pinoxaden to environmental organisms is not strong, but it is moderately toxic to some aquatic organisms such as algae, and has slight effects on the plants applied. Applying a certain dose of pinoxaden to grain field...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/093C07C25/02C07C29/36C07C33/20C07C51/16C07C57/30
CPCC07C17/093C07C29/36C07C51/16C07C25/02C07C33/20C07C57/30
Inventor 卜龙张璞钱梓伟高鹋王凤云侯远昌
Owner JIANGSU FLAG CHEM IND
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