Method for generating byproduct of low carbonate ester in fipronil intermediate precursor production process

A production process and intermediate technology, applied in chemical instruments and methods, preparation of carboxylic acid esters, preparation of organic compounds, etc., to achieve the effect of reducing salt content and CODcr

Inactive Publication Date: 2018-06-29
曾舟华
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for by-producting low-carbon esters in the production process of fipronil intermediates in view of the shortcomings of the existing production process of fipronil intermediates

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] 1) Under an ice-salt bath, slowly drop a mixed solution of 30 mL of concentrated sulfuric acid and 30 mL of formic acid into a 250 mL three-necked flask containing 0.12 mol and 8.3 g of sodium nitrite, and keep the reaction temperature at 0-5°C to obtain a thin paste shape. After continuing to stir and react for 15 minutes, add 0.1mol of 2,6-dichloro-4-trifluoromethylaniline and 50mL of 23g formic acid solution to the system dropwise. The reaction solution was cooled to obtain a light brown diazotization solution;

[0016] 2) Keep the diazotization solution below 15°C, add 0.12 mol of methyl 2,3-dicyanopropionate and 50 mL of 16 g formic acid solution dropwise, and continue stirring for 1 hour to obtain a condensate;

[0017] 3) Add 130mL of methanol to the condensation liquid, heat to 32°C, and carry out reactive distillation to obtain methyl formate as a by-product;

[0018] 4) Cool the residual liquid to normal temperature, add 50 mL of water to dilute, extract 3 t...

Embodiment 2

[0020] 1) Under the ice-salt bath, slowly drop the mixed solution of 30L concentrated sulfuric acid and 30L glacial acetic acid into a 250L reaction kettle equipped with sodium nitrite 0.12kmol, 8.3kg, and keep the reaction temperature at 0-5°C to obtain dilute paste. After continuing to stir and react for 15 minutes, add 0.1kmol of 2,6-dichloro-4-trifluoromethylaniline and 50L of 23kg of glacial acetic acid solution into the system dropwise. , the reaction solution was cooled to obtain a light brown diazotization solution;

[0021] 2) Keep the diazotization solution below 15°C, add 0.12kmol of methyl 2,3-dicyanopropionate and 50L of 16kg glacial acetic acid solution dropwise, and continue stirring for 1 hour to obtain a condensate;

[0022] 3) Add 130L of methanol to the condensation reaction liquid, heat it, carry out rectification under reduced pressure to obtain methyl acetate by-product, add a small amount of 50L of water to dilute the residual liquid, extract 3 times wi...

Embodiment 3

[0025] 1) Under the ice-salt bath, slowly drop the mixed solution of 30L concentrated sulfuric acid and 30L glacial acetic acid into a 250L reaction kettle equipped with sodium nitrite 0.12kmol, 8.3kg, and keep the reaction temperature at 0-5°C to obtain dilute paste. After continuing to stir and react for 15 minutes, add 0.1kmol of 2,6-dichloro-4-trifluoromethylaniline and 50L of 23kg formic acid solution to the system dropwise. The reaction solution was cooled to obtain a light brown diazotization solution;

[0026] 2) Keep the diazotization solution below 15°C, add 0.12kmol of ethyl 2,3-dicyanopropionate and 50L of 18kg glacial acetic acid solution dropwise, and continue stirring for 1 hour to obtain a condensate;

[0027] 3) Add a small amount of water to the condensation reaction solution for dilution, extract 3 times with 50 L of dichloromethane, wash with saturated sodium chloride solution to obtain an organic phase, condense the inorganic phase and the washing solutio...

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PUM

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Abstract

The invention discloses a method for generating a byproduct, namely low carbonate ester, in the fipronil intermediate precursor production process, and aims to solve the problem that an organic solvent is discharged in a conventional process. The method is characterized by comprising the following steps: with acetic acid of a conventional process as a solvent, replacing acetic acid with low carbonacids such as formic acid and propionic acid as a solvent, and preferably optioning the formic acid as the solvent; and putting one alcohol of low carbon alcohols such as methanol, ethanol and propanol into a condensation reaction liquid, condensation extraction inorganic phase or a detergent, preferably adding methanol, heating, and performing normal-pressure or vacuum esterification reaction distillation, thereby obtaining a low polycarbonate byproduct. The method has the beneficial effects that the content of salts in production wastewater is reduced, CODcr in the production wastewater isreduced, and a low carbonate ester product can be also produced as a byproduct.

Description

1. Technical field [0001] The invention belongs to the fields of organic synthesis, resource recovery and environmental protection, and particularly relates to a method for by-producing low-carbon esters in the production process of fipronil intermediates. 2. Background technology [0002] Fipronil is a phenylpyrazole insecticide with a wide insecticidal spectrum. It mainly has gastric toxicity to pests, and also has contact killing and certain systemic effects. Its mechanism of action is to hinder insect γ-aminobutyric acid Controlled chloride metabolism, so it has high insecticidal activity against important pests such as aphids, leafhoppers, planthoppers, Lepidoptera larvae, flies and Coleoptera, and has no phytotoxicity to crops. The agent can be applied to the soil or sprayed on the leaves. Applying to the soil can effectively control corn root leaf beetle, wireworm and cutworm. When sprayed on the leaves, it has a high level of control effect on diamondback moth, cab...

Claims

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Application Information

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IPC IPC(8): C07D231/38C07C67/08C07C67/54C07C69/06C07C69/14
CPCC07C67/08C07C67/54C07D231/38C07C69/06C07C69/14
Inventor 曾舟华刘晓晖曾彩红黄春保冉敬文
Owner 曾舟华
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