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New high-yield preparation method of azoxystrobin

A kind of azoxystrobin, high-yield technology, applied in the field of new high-yield preparation of azoxystrobin, can solve the problems of high production cost, low yield of front intermediates, low total yield of azoxystrobin, etc., to achieve production cost The effect of reducing and simplifying the production process

Inactive Publication Date: 2015-06-03
SHANGHAI TAIHE INT TRADE CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

What these patents disclose basically is the research content and achievement of the last step etherification reaction, promptly use divinylpiperazine catalyst to catalyze the last step etherification reaction, although the yield of this step reaches more than 90%, the yield of the front intermediate is not high. High, the general yield is between 70-80%, and the total yield is about 63-72%, which does not solve the problem of low total yield of azoxystrobin and high production cost

Method used

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  • New high-yield preparation method of azoxystrobin

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] (1) Preparation of 4-chloro-6-(2-cyanophenoxy)-pyrimidine

[0030] Drop into 45.6 gram 4,6-dichloropyrimidine (98%, 0.3mol), 39.5 gram salicylonitrile (95%, 0.315mol), 13.1 gram sodium hydroxide (96%, 0.314mol) and 350 ml of toluene, stirred evenly at room temperature, then 1.1 g of 2-methyldivinylpiperazine was added, stirred and heated to 60°C for 3 hours, then heated to 80-85°C for another 1 hour. Cool down, filter, add water, stir and wash twice, remove the solvent, add methanol to recrystallize, and obtain 67.2 grams of off-white 4-chloro-6-(2-cyanophenoxy)-pyrimidine crystals (purity 98.5%, 0.287mol), Yield 95.5%.

[0031] (2) Preparation of azoxystrobin

[0032]58.6 grams of 4-chloro-6-(2-cyanophenoxy)-pyrimidine (98.5%, 0.25mol), 63.2 grams of (E)-3-methoxy-2-(2 -Hydroxyphenyl)-methyl acrylate (95%, 0.25mol), 19.6 grams of sodium hydroxide (96%, 0.47mol) and 300 milliliters of toluene, stirred at room temperature, then dropped into 0.8 grams of 2-methyldiviny...

Embodiment 2

[0034] One-pot preparation of azoxystrobin

[0035] Drop into 45.6 gram 4,6-dichloropyrimidine (98%, 0.3mol), 39.5 gram salicylonitrile (95%, 0.315mol), 13.1 gram sodium hydroxide (96%, 0.314mol) and 350 ml of toluene, stirred evenly at room temperature, then 1.1 g of 2-methyldivinylpiperazine was added, stirred and heated to 60°C for 3 hours, then heated to 80-85°C for another 1 hour. Cool down, filter, and return the filtrate to a three-necked flask, add 72.9 grams of (E)-3-methoxy-2-(2-hydroxyphenyl)-methyl acrylate (95%, 0.30mol), 23.3 grams of sodium hydroxide (96%, 0.56mol), stirred evenly at room temperature, then added 0.5 g of 2-methyldivinylpiperazine, stirred and heated to 85-90° C. for 8 hours. Cool, add water, stir and wash twice, remove the solvent, recrystallize the crude product with methanol, and finally obtain 99.7 g of light yellow azoxystrobin crystals (purity 98.2%, 0.243 mol), yield 81.0%.

Embodiment 3

[0037] A new high-yield method for preparing azoxystrobin, using a reverse two-step etherification reaction to synthesize azoxystrobin, specifically comprising the following steps:

[0038] (1) by o-hydroxybenzonitrile (compound B) and 4,6-dichloropyrimidine (compound C) in the presence of catalyst 2-methyldivinylpiperazine in the solvent toluene to carry out etherification earlier to obtain 4-chloro- 6-(2-cyanophenoxy)-pyrimidine (compound D); wherein the molar ratio of compound B, compound C and catalyst is 1:0.9:0.0005; the reaction temperature is 0°C;

[0039] (2) Carry out etherification by compound D and (E)-3-methoxy-2-(2-hydroxyphenyl)-methyl acrylate (compound E) in the presence of catalyst 2-methyldivinylpiperazine Azoxystrobin was obtained by the reaction; the molar ratio of the compound D, the compound E and the catalyst was 1:0.9:0.0005; the reaction temperature was 0°C; the obtained azoxystrobin was purified by recrystallization in the solvent methanol.

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Abstract

The invention relates to a new high-yield preparation method of azoxystrobin. The method adopts a backward two-step etherification reaction to synthesize azoxystrobin, and concretely comprises the following steps: 1, carrying out an etherification reaction on 2-hydroxybenzonitrile (a compound B) and 4,6-dichloropyrimidine (a compound C) in the presence of a catalyst to obtain 4-chloro-6-(2-cyanphenoxyl)-pyrimidine (a compound D); and 2, carrying out an etherification reaction on the compound D and (E)-3-methoxy-2-(2-hydroxyphenyl )-methyl acrylate in the presence of the catalyst to obtain azoxystrobin, wherein the same catalyst is used in the two-step etherification reaction, and is a compound F. The method improves the total yield to 80-85%.

Description

technical field [0001] The invention relates to the preparation of a pesticide, in particular to a new method for preparing azoxystrobin with high yield. Background technique [0002] Azoxystrobin is currently the world's largest agricultural fungicide product, with broad-spectrum, high-efficiency, and is widely produced and used. The synthesis of azoxystrobin generally starts with benzofuranone (compound G) in sodium methoxide / methanol solution and 4,6-dichloropyrimidine (compound C) for ring-opening and etherification reactions, and then in the presence of potassium bisulfate Carry out elimination reaction to obtain (E)-3-methoxy-2-(2-(4-chloro-6-pyrimidinyl)oxyphenyl)-methyl acrylate (compound H), and finally by compound H and o-hydroxybenzene Carbonitrile (commonly known as salicylonitrile) is etherified to obtain azoxystrobin. In order to increase the yield of the product, it is generally necessary to use a catalyst to promote the reaction. Now most domestic enterpri...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D239/52B01J31/02
CPCC07D239/52B01J31/0244B01J2231/4288
Inventor 田晓宏谢思勉周庆江李建高张照军
Owner SHANGHAI TAIHE INT TRADE CO LTD
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