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Preparation method of high-yield and high-purity insecticide diflubenzuron

A diflubenzuron, high-purity technology, applied in the field of preparation of high-yield, high-purity pesticide diflubenzuron, can solve the problems of unreasonable solvent, complicated process, large amount of raw materials added, etc., and improve the output of a single kettle , improve the reaction yield, improve the effect of product content

Active Publication Date: 2021-12-31
TAIZHOU BAILLY CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The preparation method of diflubenzuron described in the prior art has the following disadvantages: (1) the process is complicated, and the catalyst used is unreasonable, resulting in low synthesis yield and purity and high preparation cost; (2) the solvent used Unreasonable, resulting in excessive addition of raw materials, and cannot guarantee that the amount of raw materials will reach the saturation of the reaction system
[0004] Chinese patent CN201110083617.0 discloses a method for preparing the insecticide diflubenzuron. Using dimethylformamide and p-chloroaniline as starting materials, under the action of phosgene, catalyst and co-catalyst, the reaction produces p-chloro A solution composed of phenylisocyanate and aromatic compound solvent, and then dropwise adding the above obtained p-chlorophenylisocyanate and aromatic compound solvent in the mixture of aromatic compound solvent and 2,6-difluorobenzamide to obtain diflubenzuron; The improvement of its yield and purity is because of its use of two kinds of catalysts and cocatalysts, but also improves the preparation cost, and in the aromatic compound solvent and 2,6-difluorobenzamide mixture, p-chlorophenyl isocyanate and aromatic The process of compound solvents did not take into account the side reactions of moisture in aromatic compound solvents, etc., which would affect the yield and purity of diflubenzuron
The yield of diflubenzuron in this patent is greater than 92%, and the purity is greater than 97%, which still has a certain gap with the purity higher than 98% required by the market

Method used

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  • Preparation method of high-yield and high-purity insecticide diflubenzuron

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] In a 500mL four-neck flask, add 187.5g of mixed xylene and 37.5g of 2,6-difluorobenzamide, mix and stir, the system is heated up to 145°C, maintain the reflux state, and 19g of mixed xylene (brought out of the system free all water); drop 38.3g of p-chlorophenyl isocyanate, the dropwise addition is completed within 2 hours, and continue to insulate and stir at 145°C for 4 hours; after the reaction is completed, 62g of mixed xylenes are released; Filter, take cold mixed xylene (temperature 0~10°C, can reduce the solubility of the material in mixed xylene) to wash the filter cake, and dry to obtain the finished product of diflubenzuron with a content of 99.24% and a yield of 95.57% (with 2 , 6-difluorobenzamide).

Embodiment 2

[0028] In a 500mL four-neck flask, add 220g of mixed xylene and 44.0g of 2,6-difluorobenzamide, mix and stir, the system is heated to 145°C, maintain the reflux state, and 26g of mixed xylene (brought out of the system free 44.9g of p-chlorophenyl isocyanate was added dropwise, and the dropwise addition was completed within 2.5 hours, and continued to be kept and stirred at 145°C for 4.5 hours; after the reaction, 72g of mixed xylene was released; the system was cooled to 10°C, filtered , wash the filter cake with cold mixed xylene (temperature 0-10°C), and dry to obtain the finished product of diflubenzuron, with a content of 99.57% and a yield of 96.10% (calculated as 2,6-difluorobenzamide).

Embodiment 3

[0030] In a 500mL four-necked flask, add 220g of mixed xylene and 44.0g of 2,6-difluorobenzamide, mix and stir; the system is heated to 145°C, maintains the reflux state, and 26g of mixed xylene (brought out of the system as free 44.9g of p-chlorophenyl isocyanate was added dropwise, and the dropwise addition was completed within 2 hours, and continued to be kept at 145°C for 4 hours while stirring after the drop; after the reaction, 72g of mixed xylene was released; the system was cooled to 10°C, filtered , take a small amount of cold mixed xylene (temperature 0-10°C) to wash the filter cake, and dry it to obtain the finished product of diflubenzuron, with a content of 99.28% and a yield of 96.08% (calculated as 2,6-difluorobenzamide).

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Abstract

The invention relates to a preparation method of a high-yield and high-purity insecticide diflubenzuron. The preparation method comprises the following steps: mixing mixed xylene and 2, 6-difluorobenzamide, heating and refluxing to remove part of the mixed xylene, dropwise adding p-chlorophenyl isocyanate, carrying out heat preservation reaction after dropwise adding is ended, removing part of the mixed xylene after the reaction is ended, and performing cooling post-treatment to obtain the diflubenzuron. According to the preparation method of the high-yield and high-purity insecticide diflubenzuron, the mixed xylene is adopted as the solvent, the cost is low, the quality is high, the yield of the prepared diflubenzuron is 95% or above, the content of the diflubenzuron finished product is 99% or above, and the preparation method is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of insecticide preparation, and in particular relates to a preparation method of a high-yield, high-purity insecticide diflubenzuron. Background technique [0002] Diflubenzuron is an insect growth regulator with specificity and low toxicity, belonging to the benzoyl phenylurea insecticides. Its insecticidal mechanism is to inhibit the chitin synthesis of insects, so that the larvae cannot form a new epidermis when moulting, and the insect body becomes deformed and dies. The medicine is effective against various pests of Lepidoptera, and has no phytotoxicity to plants under effective dosage, and has no adverse effects on beneficial organisms such as birds, fish, shrimps, frogs, bees, ladybugs, and parasitic wasps. [0003] The preparation method of diflubenzuron described in the prior art has the following disadvantages: (1) the process is complicated, and the catalyst used is unreasonable, resulting in low...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C273/18C07C275/54
CPCC07C273/1827C07C275/54
Inventor 胡红一赵辉汪静莉杨露常亚军方炎林梅渝晨
Owner TAIZHOU BAILLY CHEM CO LTD