Preparation method of lambda-cyhalothrin

A technology of high-efficiency cyfluthrin and cyfluthrin, which is applied in the field of pesticide chemical industry, can solve the problems of difficult industrialized production, harsh reaction conditions, complicated preparation process, etc., and achieves the effects of reducing distillation recovery, improving reaction rate and simple process flow

Inactive Publication Date: 2013-12-04
LIANYUNGANG CCA CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, there are mainly three preparation methods for beta-cyfluthrin in the prior art, but there are many problems in the preparation method of beta-cyfluthrin in the prior art: complex preparation process, long process route, h

Method used

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  • Preparation method of lambda-cyhalothrin

Examples

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Effect test

Embodiment 1

[0019] (1) Synthesis of Dichlorochrysanthemum Acid Chloride:

[0020] In a 1000ml four-necked flask equipped with a thermometer, ventilation duct, and tail gas exhaust pipe, put 400ml of n-hexane, add 210g of permethrin, add 1.2g of DMF as a catalyst under stirring, add 136g of thionyl chloride dropwise under heating, and dropwise add After completing the heat preservation reaction for 6 hours, GC tracked and detected the complete conversion of permethrin, and recovered excess thionyl chloride by distillation under reduced pressure to obtain 404 g of permethrin-chloride n-hexane solution.

[0021] (2) Synthesis of cyfluthrin:

[0022] Put 28.5g of sodium cyanide and 130g of water into a 1000ml reaction bottle, stir until completely dissolved, add 0.108g of trioctylmethyl ammonium chloride and 108g of fluoroether aldehyde, stir and add 202g of dichlorochrysanthemum chloride-n-hexane solution drop by drop Add temperature at 25°C, add dropwise evenly for 3 hours, take samples fo...

Embodiment 2

[0026] Change the reaction condition of the first step, other steps are as embodiment 1, namely:

[0027] (1) Synthesis of Dichlorochrysanthemum Acid Chloride:

[0028] In a 1000ml four-necked flask equipped with a thermometer, a ventilation duct, and an exhaust pipe, put 400ml of n-hexane, add 210g of permethrin, add 3.0g of DMF as a catalyst under stirring, add 160g of thionyl chloride dropwise under heating, and dropwise add After completing the heat preservation reaction for 2 hours, GC tracked and detected the complete conversion of permethrin, and recovered excess thionyl chloride by distillation under reduced pressure to obtain 405 g of permethrin-chloride n-hexane solution.

Embodiment 3

[0030] Change the reaction condition of the 3rd step, other steps are as embodiment 1, namely:

[0031] (3) Synthesis of beta-cyfluthrin:

[0032] Add 390g of cyfluthrin n-hexane solution into a stirred four-necked flask equipped with a thermometer, stir and add 39g of epimerization catalyst (that is, a composite catalyst of triethylamine:diisopropylamine=4:6) at 25°C, and then Keep warm for 8 hours, add 19.5g seed crystals at 20°C and keep warm for 12 hours, keep warm at 15°C for 48 hours, and keep warm at 10°C for 24 hours. Sampling was performed to detect that the α-body content reached 95%, then the reaction was terminated, and 203 g of lambda-cyfluthrin was obtained by suction filtration and drying.

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Abstract

The invention discloses a preparation method of lambda-cyhalothrin. The preparation method of the lambda-cyhalothrin comprises the steps that 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid serves as an initial raw material, DMF serves as a catalyst, n-hexane serves as solvent, an n-hexane solution of 3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropanecarbonyl chloride is obtained, a reaction among the n-hexane solution of the 3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropanecarbonyl chloride, 3-phenoxy-4-fluoro-benzaldehyde and sodium cyanide is carried out, methyl trioctyl ammonium chloride serves as a catalyst, a condensation reaction is carried out to obtain a cyhalothrin condensation compound, washing and desalting are carried out on the cyhalothrin condensation compound to obtain a cyhalothrin n-hexane solution, a composite catalyst is directly added to the cyhalothrin n-hexane solution, and an epimerization reaction is carried out to obtain the lambda-cyhalothrin. Compared with the prior art, the technological process is simple, the solvent does not need to be replaced in the process of preparation, the situation that isopropanol is used for carrying out working procedures such as rectification and dewatering is avoided, and the same solvent is adopted; due to the fact that the composite catalyst is adopted, the rate of the epimerization reaction is improved, and due to the facts that the n-hexane serves as epimerization solvent, and the isopropanol is not adopted, the working procedure of distillation recycling of the isopropanol and the working procedure of dewatering of the isopropanol are omitted, material loss is reduced, production cost is reduced, industrial production can be easily carried out, and popularization prospect and application prospect are wide.

Description

technical field [0001] The invention belongs to the field of pesticide chemical industry, in particular to a preparation method of beta-cyfluthrin. Background technique [0002] Beta-cyfluthrin, the chemical name is cyano-(4-fluoro-3-phenoxybenzyl)-methyl-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate; Colorless and odorless crystals; Beta-cyfluthrin is a synthetic pyrethroid insecticide, which has contact and stomach poisoning effects, wide insecticidal spectrum, rapid knockdown, long-lasting effect, and plants have good tolerance to it Drug properties; crops for which beta-cyfluthrin is suitable: cotton, wheat, corn, vegetables, tomatoes, apples, citrus, grapes, rapeseed, soybeans, etc.; beta-cyfluthrin is effective against chewing mouthpart pests such as Lepidoptera larvae or some beetles of Coleoptera It has a good control effect, and can also be used for the control of piercing-sucking mouthpart pests such as pear psyllid; it is safe for crops; if the liquid m...

Claims

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Application Information

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IPC IPC(8): C07C255/39C07C253/30
Inventor 沈中泽王泽华
Owner LIANYUNGANG CCA CHEM CO LTD
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