A kind of synthetic technology of pyraclostrobin intermediate o-nitrobenzyl bromide

A technology for pyraclostrobin and a synthesis process, which is applied in the field of synthesis technology of pyraclostrobin intermediate o-nitrobenzyl bromide, can solve problems such as low content of o-nitrobenzyl bromide, achieve high yield and improve The effect of high content and economic benefit

Active Publication Date: 2022-04-26
浙江禾本科技股份有限公司 +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] O-nitrobenzyl bromide is an important intermediate of pyraclostrobin, the content of o-nitrobenzyl bromide produced by the current process is relatively low, the content of o-nitrobenzyl bromide is about 60%, and unreacted o-nitrotoluene is in About 29%, o-nitrotoluene can be recovered and used mechanically, but there are still 10% by-product dibromine

Method used

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  • A kind of synthetic technology of pyraclostrobin intermediate o-nitrobenzyl bromide
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  • A kind of synthetic technology of pyraclostrobin intermediate o-nitrobenzyl bromide

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Embodiment 1

[0027] A kind of synthetic technology of pyraclostrobin intermediate o-nitrobenzyl bromide

[0028] The synthetic technique of pyraclostrobin intermediate o-nitrobenzyl bromide comprises the following steps:

[0029] Step 1, 1000kg of chlorobenzene, 445kg of hydrobromic acid solution with a concentration of 48wt%, and 20kg of catalyst are added to the reaction kettle, and the temperature is raised to 75°C;

[0030] Step 2: Add 400kg of o-nitrotoluene and 250kg of hydrogen peroxide solution with a concentration of 28% dropwise into the reactor at the same time. After the addition is complete, continue the insulation reaction for 2 hours;

[0031] Step 3, put 25kg of concentrated sulfuric acid and 5kg of zinc powder into the reaction kettle in turn, control the temperature between 85-90°C, and keep it warm for 1 hour;

[0032] Step 4, standing for stratification, separating the lower organic phase, sampling and analyzing, the content of o-nitrobenzyl bromide is 78.03%, and the...

Embodiment 2

[0034] A kind of synthetic technology of pyraclostrobin intermediate o-nitrobenzyl bromide

[0035] The synthetic technique of pyraclostrobin intermediate o-nitrobenzyl bromide comprises the following steps:

[0036] Step 1, 800kg of chlorobenzene, 420kg of hydrobromic acid solution with a concentration of 45wt%, and 15kg of catalyst are added to the reactor, and the temperature is raised to 70°C;

[0037] Step 2, add 380kg of o-nitrotoluene and 270kg of hydrogen peroxide solution dropwise at the same time in the reactor, the temperature is controlled at 75°C, and the rate of addition is controlled so that the addition of o-nitrotoluene and hydrogen peroxide solution is completed in 2 hours. Continue the insulation reaction for 1.5 hours;

[0038] Step 3, put 20kg of concentrated sulfuric acid and 2kg of zinc powder into the reaction kettle in turn, control the temperature between 85°C and keep it warm for 1 hour;

[0039] Step 4, standing for stratification, separating the ...

Embodiment 3

[0041] A kind of synthetic technology of pyraclostrobin intermediate o-nitrobenzyl bromide

[0042] The synthetic technique of pyraclostrobin intermediate o-nitrobenzyl bromide comprises the following steps:

[0043] Step 1, 1200kg of chlorobenzene, 460kg of hydrobromic acid solution with a concentration of 50wt%, and 25kg of catalyst are added to the reactor, and the temperature is raised to 80°C;

[0044] Step 2, add 420kg o-nitrotoluene and 240kg concentration of 30% hydrogen peroxide solution to the reactor simultaneously, control the temperature at 85°C, and control the rate of addition so that the o-nitrotoluene and hydrogen peroxide solution are added dropwise in 2 hours, Continue to keep warm for 2 hours;

[0045] Step 3, put 30kg of concentrated sulfuric acid and 8kg of zinc powder into the reaction kettle in turn, control the temperature between 85-90°C, and keep it warm for 1 hour;

[0046] Step 4, standing for stratification, separating the lower organic phase, s...

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Abstract

The invention discloses a synthesis process of pyraclostrobin intermediate o-nitrobenzyl bromide, which comprises the following steps: adding chlorobenzene, hydrobromic acid solution and a catalyst into a reaction kettle, raising the temperature; Add o-nitrotoluene and hydrogen peroxide solution, and continue to keep warm for 2 hours; put concentrated sulfuric acid and zinc powder into the reaction kettle in turn, control the temperature between 85-90°C, keep warm for 1 hour; let stand to separate layers, and separate the lower layer The organic phase was sampled and analyzed to obtain o-nitrobenzyl bromide. The content of o-nitrobenzyl bromide obtained by the synthesis process of o-nitrobenzyl bromide of the present invention is more than 75%, and the content of by-product dibromine is below 0.5%. Compared with the old technology, it has high yield and few by-products characteristics, and the synthesis process does not require additional equipment, the process operation is simple, and the economic benefit is high.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a synthesis process of pyraclostrobin intermediate o-nitrobenzyl bromide. Background technique [0002] O-nitrobenzyl bromide is an important intermediate of pyraclostrobin, the content of o-nitrobenzyl bromide produced by the current process is relatively low, the content of o-nitrobenzyl bromide is about 60%, and unreacted o-nitrotoluene is in About 29%, o-nitrotoluene can be recovered and used mechanically, but there is still 10% by-product dibromine. Now the process is as follows: o-nitrotoluene, catalyst, hydrogen bromide and hydrogen peroxide in chlorobenzene, bromination reaction to obtain o-nitrobenzyl bromide. [0003] The reaction equation is as follows: [0004] [0005] side effects: [0006] Contents of the invention [0007] In view of the above problems, the present invention provides a synthesis process of pyraclostrobin intermediate o-nitrob...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C201/12C07C201/16C07C205/11
CPCC07C201/12C07C201/16C07C205/11
Inventor 王进潘光飞徐瑶陈华曾挺
Owner 浙江禾本科技股份有限公司
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