Process for preparing high-purity ethiprole through oxidation method

A technology of ethiprole and high purity, which is applied in the field of production and preparation of high-purity ethiprole, and can solve problems such as low yield, high cost, and complicated separation

Active Publication Date: 2015-02-25
ZHEJIANG HISUN CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The existing production process of ethiprole generally faces problems such as high cost, high toxicity of raw materials, high pollution, low yield, complicated separation, etc.

Method used

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  • Process for preparing high-purity ethiprole through oxidation method

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] Add 10.287kg (27mol) of ethiprole oxidation precursor, 107.26kg (1083mol) of dichloroethane into a 100L reactor, add 4.212kg (70.2mol) of acetic acid and 6.8175kg (70.2mol) of 35% hydrogen peroxide, and stir at 30°C About 10 hours. Sampling and follow-up, after the reaction was completed, 3.285 kg (31.6 mol) of sodium sulfite was slowly added, and the exotherm was obvious, which was controlled within 55 °C. Add sodium hydroxide solution to adjust the pH to 6-7, then heat up to reflux (about 80°C), then cool to below 10°C, crystallize, and filter with suction to obtain 10.50kg of crude solid, with a purity of 98.7%, and a crude yield of 96%, containing The peroxide impurity is 0.5%. After one recrystallization, the fine product with peroxidic impurity less than 0.3% is obtained, and the fine product yield is 93%.

[0041] The purity of the synthetic ethiprole: 99.4% (HPLC).

Embodiment 2

[0043] Add 10.287kg (27mol) of ethiprole oxidation precursor, 107.26kg (1083mol) dichloroethane layer into a 100L reactor, add 1.62kg (27mol) of acetic acid and 6.8175kg (70.2mol) of 35% hydrogen peroxide, and stir at 30°C About 20 hours. Sampling and follow-up, after the reaction was completed, 3.285 kg (31.6 mol) of sodium sulfite was slowly added, and the exotherm was obvious, which was controlled within 55 °C. Add sodium hydroxide solution to adjust the pH to 6-7, then heat up to reflux (about 80°C), then cool to below 10°C, crystallize, and filter with suction to obtain 10.41kg of crude solid, with a purity of 98.3%, and a crude yield of 95%, containing The peroxide impurity is 0.6%. After one recrystallization, the fine product with peroxidic impurity less than 0.3% is obtained, and the fine product yield is 92%.

[0044] The purity of the synthetic ethiprole: 99.3% (HPLC).

Embodiment 3

[0046] Add 10.287kg (27mol) of ethiprole oxidation precursor, 107.26kg (1083mol) of dichloroethane layer into a 100L reactor, add 4.212kg (70.2mol) of acetic acid and 6.8175kg (70.2mol) of 35% hydrogen peroxide, 30°C Stir for about 18 hours. Sampling and follow-up, after the reaction was completed, 3.285 kg (31.6 mol) of sodium sulfite was slowly added, and the exotherm was obvious, which was controlled within 55 °C. Add sodium hydroxide solution to adjust the pH to 6-7, then heat up to reflux (about 80°C), then cool to below 10°C, crystallize, and filter with suction to obtain 10.40kg of crude solid, with a purity of 97.8%, and a crude yield of 95%, containing The peroxide impurity is 0.8%. After recrystallization twice, a fine product with peroxidic impurity less than 0.3% is obtained, and the fine product yield is 91%.

[0047] The purity of the synthetic ethiprole: 99.1% (HPLC).

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PUM

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Abstract

The invention discloses a process for preparing high-purity ethiprole through an oxidation method. The process comprises the following steps of: carrying out oxidation reaction on a right amount of raw material 5-amido-3-cyano-group-1-(2,6-dichloro-4-trifluoromethyl phenyl)-4-ethyl sulfinyl pyrazole (I) in an organic solvent with the participation of fatty acid and hydrogen peroxide; after the oxidation reaction is finished, adding a reducing agent and controlling the temperature of a system at the same time; then regulating the pH value of the system through an NaOH solution; then heating, refluxing, cooling, crystallizing and carrying out suction filtration to obtain a crude ethiprole product; purifying the crude ethiprole product (II) so as to obtain a qualified product, wherein the organic solvent is selected from at least one of chloroform, dichloromethane and dichloroethane. The production process disclosed by the invention has the advantages of simplicity, high efficiency, few by-products, bigger breakthrough on product yield and product purity, relatively low raw material toxicity, little environmental pollution and good production controllability.

Description

[0001] technical field [0002] The invention relates to a production, preparation and purification process of N-phenylpyrazole compounds, in particular to a production and preparation method of high-purity pyretafenil. [0003] Background technique [0004] Ethpronil is an arylpyrazole insecticide whose biological properties are similar to butylene fipronil. It is a low-toxic insecticide, non-mutagenic, non-irritating and non-sensitizing to skin and eyes, and effective against a variety of chewing and piercing-sucking pests. The mode of action is contact killing, and its mechanism of action is through γ -Aminobutyl ester interferes with chloride ion channels, thereby disrupting the normal activities of the central nervous system and causing the death of pests. Commercially available products are generally 100 g / L suspending agent. [0005] Ethpronil is effective against a variety of chewing and piercing-sucking pests at low dosages. It can be used for seed treatment and ...

Claims

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Application Information

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IPC IPC(8): C07D231/44
CPCC07D231/44
Inventor 包如胜王丽敏蒋富国李劲徐坚勇
Owner ZHEJIANG HISUN CHEM
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