Synthetic method for preparing pyraclostrobin intermediate from o-nitrobenzyl chloride

A technology of pyraclostrobin and o-nitrobenzyl chloride, which is applied in the field of synthesis of organic compounds, can solve the problems of many by-products, low yield, and small yield, and achieve the reduction of environmental protection pressure, simple synthesis process, and low The effect of production costs

Inactive Publication Date: 2016-08-17
SICHUAN FOURSTAR BIOTECH RANDD CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The yield of thermal chlorination method is low, the general yield is less than 5%
On the one hand, the light chlorination method is inconvenient to use light, on the other hand, there are many by-products, and the reaction effect is not good.
Therefore, at present, o-nitrobenzyl chloride does not yet have a low-cost, economically applicable effective synthetic method

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] In the present embodiment, the synthetic process of o-nitrobenzyl chloride is as follows:

[0035] Add catalyst (50 mesh activated carbon) into o-nitrotoluene, control the mass ratio of o-nitrotoluene to catalyst at 1:0.01, stir at 200r / min and heat to 100°C, slowly introduce chlorine gas, and track with gas chromatography The reaction by-product o-nitrobenzylidene dichloride reached 4%, the conversion rate of o-nitrotoluene was 39.7%, and the reaction was stopped; after the reaction was completed, under reduced pressure distillation at a vacuum degree of -0.097Mpa and a temperature of 110°C, the o-nitrotoluene was recovered. Toluene is continuously chlorinated and utilized; the residue after recovery of o-nitrotoluene is recrystallized and purified with petroleum ether to obtain white crystal o-nitrobenzyl chloride solid powder.

[0036] In this embodiment, the production effect of o-nitrobenzyl chloride with a purity of 99.3% and a yield of 83.7% (based on the actual ...

Embodiment 2

[0038] In the present embodiment, the synthetic process of o-nitrobenzyl chloride is as follows:

[0039] Add the catalyst (a mixture of activated carbon and DMF at a mass ratio of 2:1200 mesh) to o-nitrotoluene, control the mass ratio of o-nitrotoluene to catalyst at 1:0.2, stir at 400r / min and heat to 180°C , slowly feed chlorine gas, track the reaction by-product o-nitrobenzylidene dichloride with gas chromatography to reach 6%, and the conversion rate of o-nitrotoluene is 41%, stop the reaction; Distill under reduced pressure at ℃ to recover o-nitrotoluene, and continue to recycle chlorination; the residue after recovering o-nitrotoluene is recrystallized and purified with petroleum ether to obtain white crystalline solid powder of o-nitrobenzyl chloride.

[0040] In this embodiment, the production effect of o-nitrobenzyl chloride with a purity of 99.6% and a yield of 80.0% can be achieved (based on the actual consumption of o-nitrotoluene).

Embodiment 3

[0042] In the present embodiment, the synthetic process of o-nitrobenzyl chloride is as follows:

[0043] Add a catalyst (a mixture of bromine, azobisisobutyronitrile and azobisisoheptanonitrile in a mass ratio of 1:1:2) to o-nitrotoluene, and control the mass ratio of o-nitrotoluene to catalyst at 1 : 0.15, stirring at a speed of 300r / min and heating to 130°C, slowly introducing chlorine gas, tracking the reaction by-product o-nitrobenzylidene dichloride with gas chromatography to reach 5%, and the conversion rate of o-nitrotoluene is 40.2%, stop the reaction; After the reaction is over, distill under reduced pressure at a vacuum degree of -0.097Mpa and a temperature of 115°C to recover o-nitrotoluene and continue to circulate chlorination; the residue after recovery of o-nitrotoluene is recrystallized and purified with petroleum ether to obtain a white Crystalline o-nitrobenzyl chloride solid powder.

[0044] In this embodiment, the production effect of o-nitrobenzyl chlori...

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Abstract

The invention discloses a synthetic method for preparing pyraclostrobin intermediate from o-nitrobenzyl chloride, which comprises the following steps: adding a catalyst into o-nitrotoluene, heating and stirring, and slowly introducing chlorine gas, and after the reaction is finished, , reclaim o-nitrotoluene to obtain o-nitrobenzyl chloride; carry out etherification reaction with o-nitrobenzyl chloride and 1-(4-chlorophenyl)-3-pyrazolol to obtain 2-[(N- 4-chlorophenyl)-3-pyrazolyloxymethyl]nitrobenzene. The present invention replaces o-nitrobenzyl bromide with o-nitrobenzyl chloride and reacts with 1-(4-chlorophenyl)-3-pyrazolol to prepare pyraclostrobin intermediate 2-[(N-4 -Chlorophenyl)-3-pyrazolyloxymethyl]nitrobenzene, which avoids the defects of the existing synthetic method using o-nitrobenzyl bromide, and can prepare ethers with a content of ≥98% and a yield of ≥90%. chemical products.

Description

technical field [0001] The invention is a synthetic method for preparing pyraclostrobin intermediate from o-nitrobenzyl chloride, in particular to the preparation of pyraclostrobin intermediate 2-[(N-4-chlorophenyl )-3-pyrazolyloxymethyl] the synthetic technique of nitrobenzene belongs to the synthetic field of organic compound. Background technique [0002] Since pyraclostrobin was launched by BASF in 2002, it has received extensive attention and application. As an effective broad-spectrum fungicide, pyraclostrobin has a good control effect on diseases caused by all types of true pathogens. For example: potato and tomato early blight, late blight, leaf bitterness, powdery mildew, rust, etc., have the effect of prevention and cure. [0003] O-nitrobenzyl bromide is an important synthetic intermediate of the new broad-spectrum fungicide pyraclostrobin, which can react with 1-(4-chlorophenyl)-3-pyrazolol to produce pyraclostrobin Intermediate 2-[(N-4-Chlorophenyl)-3-pyrazol...

Claims

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Application Information

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IPC IPC(8): C07D231/22
CPCC07D231/22
Inventor 王文马青伟刘虎陈熙李舟张华王蕾
Owner SICHUAN FOURSTAR BIOTECH RANDD CORP
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