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Preparation method for intermediate of pyrethroid compound

A technology for pyrethroids and intermediates, which is applied in the field of preparation of pyrethroids intermediates, can solve the problems of low yield, poor quality, and poor industrial safety and reliability, and achieves the effect of easy control of the reaction

Inactive Publication Date: 2005-04-13
JIANGSU YANGNONG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Tetrafluoro-p-methylbenzyl alcohol is an important intermediate for the synthesis of tefluthrin. There are many synthetic pathways for this intermediate, but there are problems of poor quality, low yield, and poor industrial safety and reliability.

Method used

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  • Preparation method for intermediate of pyrethroid compound
  • Preparation method for intermediate of pyrethroid compound
  • Preparation method for intermediate of pyrethroid compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] In a 2000ml four-necked flask, put methanol 500ml, sodium borohydride 37g, heat up to 50°C, keep warm for 1 hour, put 266g of tetrafluoromethyl-terephthalate, and continue to react at 50°C for 5 hours , cooled to room temperature, hydrolyzed with 300ml of 30% hydrochloric acid, then extracted with 500ml of carbon tetrachloride, and sloughed off carbon tetrachloride under reduced pressure to obtain 173g of white solid tetrafluoro-p-phenylenedimethanol, the content was 97.7%, and the yield was 80.5 %

Embodiment 2

[0018] In a 2000ml four-necked flask, put 500ml of ethanol, 54g of potassium borohydride, heat up to 50°C, keep warm for 1 hour, put 266g of methyl tetrafluoro-terephthalate, and continue to react at 50°C for 5 hours , cooled to room temperature, hydrolyzed with 300ml of 30% hydrochloric acid, then extracted with 500ml of carbon tetrachloride, and sloughed off carbon tetrachloride under reduced pressure to obtain 172.0g of tetrafluoro-p-phenylenedimethanol, with a content of 93.4%, and a yield of 76.5. %

Embodiment 3

[0020] The process is as described in (Example 1), methanol throws 37ml, the content of tetrafluoro-p-phenylenedimethanol is 88.1%, and the yield is 76%

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Abstract

The present invention relates to the preparation process of one kind of pyrethroid intermediate, named chemically 2, 3, 5, 6-tetrafluoro paraxylylene alcohol. The present invention prepares 2, 3, 5, 6-tetrafluoro paraxylylene alcohol via reducing 2, 3, 5, 6-tetrafluoro methyl terephthalate, and has the features of simple technological route, high safety and reliability and high quality and yield.

Description

technical field [0001] The invention relates to a preparation method of a pyrethroid intermediate. Background technique [0002] Pyrethroids are a class of synthetic insecticides that imitate the structure of natural pyrethrum flowers. They have the characteristics of high efficiency, low toxicity, low residue, and good environmental compatibility. They are currently a class of compounds advocated by the international pesticide industry. One such example is tefluthrin, the first pyrethroid available as a soil insecticide, highly effective against Coleoptera, Lepidoptera and Diptera. Tetrafluoro-p-methylbenzyl alcohol is an important intermediate for the synthesis of tefluthrin. There are many synthetic routes for this intermediate, but there are problems of poor quality, low yield, and poor industrial safety and reliability. How to find a synthetic route with high quality and high yield is the pursuit of many pesticide synthesis companies. ...

Claims

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Application Information

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IPC IPC(8): C07C33/46
Inventor 王东朝姜友法
Owner JIANGSU YANGNONG CHEM