阅读说明：本技术 一种dv-菊酸的合成方法 (Method for synthesizing DV-chrysanthemic acid ) 是由 张赟 于 2020-12-09 设计创作，主要内容包括：本发明提出的是一种DV-菊酸的合成方法,首先采用异戊烯醇、乙基三乙烯基在酸性条件下升温合成中间体二甲基-戊烯酸乙酯；其次加入四氯化碳、异丙醇、三氯化铝混合后,降温反应得到二氯菊酸甲酯；最后水解并减压蒸馏除去有机溶剂,得到产品DV-菊酯。本发明通过三步反应得到产品DV-菊酯,制备方法副反应小、安全、环保,适用于大批量工业生产,具有广泛的应用前景。(The invention provides a method for synthesizing DV-chrysanthemic acid, which comprises the steps of firstly heating isopentenol and ethyltrivinyl under an acidic condition to synthesize an intermediate dimethyl-ethyl pentenoate; secondly, adding carbon tetrachloride, isopropanol and aluminum trichloride, mixing, and cooling to react to obtain methyl dichlorochrysanthemate; finally, hydrolyzing and distilling under reduced pressure to remove the organic solvent to obtain the DV-pyrethrin product. The DV-pyrethrin product is obtained through three steps of reactions, and the preparation method is small in side reaction, safe, environment-friendly, suitable for large-scale industrial production and wide in application prospect.)

1. A method for synthesizing DV-chrysanthemic acid is characterized by comprising the following steps:

1) adding isoamylene alcohol and ethyl trivinyl ether into a reaction kettle;

2) heating under an acidic condition, and then carrying out heat preservation reaction to synthesize an intermediate, namely dimethyl-ethyl pentenoate;

3) continuously adding carbon tetrachloride, isopropanol and aluminum trichloride into the reaction kettle, mixing, cooling and continuously reacting to obtain methyl dichlorochrysanthemate;

4) cooling, and distilling under reduced pressure to remove the organic solvent;

5) adding the reaction product obtained in the step 4) into a reaction kettle, adding liquid caustic soda and absolute ethyl alcohol at the same time, heating and refluxing, and distilling at normal pressure to recover methanol and ethanol to obtain sodium dichlorochrysanthemate;

6) adding toluene and hydrochloric acid into a reaction kettle for acidification, standing and layering;

7) and (4) taking the oil layer, and evaporating water and toluene to obtain the DV-chrysanthemic acid product.

2. The method for synthesizing DV-chrysanthemic acid according to claim 1, wherein the ratio of the amount of the substance of prenol to ethyltrivinyl ether in step 1) is 1: 1.12.

3. the method for synthesizing DV-chrysanthemic acid according to claim 1, wherein the ethyltrivinyl ether in step 1) is added dropwise at a temperature not exceeding 30 ℃.

4. The method for synthesizing DV-chrysanthemic acid according to claim 1, wherein the acidic conditions in step 2) are realized by: introducing hydrogen chloride gas, and controlling the pH value to 3-4.

5. The method for synthesizing DV-chrysanthemic acid according to claim 1, wherein in step 2), the temperature is raised to 105 ℃ and then kept for 4 hours to ensure the reaction is complete.

6. The method for synthesizing DV-chrysanthemic acid according to claim 1, wherein the temperature in step 3) is reduced to 45 ℃ and then reaction is continued for 6h to reduce side reactions.

7. The method for synthesizing DV-chrysanthemic acid according to claim 1, wherein the heating reflux time of step 5) is 2 h.

8. The method for synthesizing DV-chrysanthemic acid according to claim 1, wherein in step 6), acidification pH is controlled to 1-2 and acidification time is 0.5 h.

Technical Field

The invention relates to a method for synthesizing DV-chrysanthemic acid, belonging to the technical field of organic synthesis.

Background

DV-chrysanthemic acid, 3- (2, 2-dichlorovinyl) -2, 2-dimethylcyclopropanecarboxylic acid, also known as dichlorochrysanthemic acid, has a molecular formula of C₈H₁₀Cl₂O₂The pyrethroid is an important intermediate for producing the pyrethroid and can be used for manufacturing various pyrethroid insecticides for sanitation or agriculture, such as permethrin, cypermethrin, alpha-cypermethrin, beta-cypermethrin, cypermethrin (mosquithrin), prallethrin, permethrin, cypermethrin, pentafluoro-fluthrin, transfluthrin, cyfluthrin (cyhalothrin), cypermethrin and the like. Compared with the traditional organophosphorus and organochlorine pesticides, the dichlorochrysanthemic acid ester pesticide has the advantages of high activity, good environmental compatibility, short residual time and low toxicity to human and livestock, but the existing DV-chrysanthemic acid synthesis preparation method has low product purity, low yield and difficult full yieldMeets the market demand; meanwhile, the intermediate additive used in the existing method has high toxicity, and is not beneficial to product purification and environmental protection.

Disclosure of Invention

The invention aims to solve the defects of the existing DV-chrysanthemic acid preparation method and provides a high-yield and high-content DV-chrysanthemic acid synthesis method.

The technical solution of the invention is as follows: a method for synthesizing DV-chrysanthemic acid specifically comprises the following steps:

1) adding isoamylol into a reaction kettle, slowly dropwise adding ethyl trivinyl ether, controlling the dropwise adding temperature to be not more than 30 ℃, and controlling the mass ratio of the isoamylol to the ethyl trivinyl ether to be 1: 1.12;

2) introducing hydrogen chloride gas into the reaction kettle, controlling the pH to be 3-4 acid condition, heating to 105 ℃, preserving the temperature and reacting for 4 hours to ensure complete reaction, and synthesizing an intermediate, namely dimethyl-ethyl pentenoate;

3) continuously adding carbon tetrachloride, isopropanol and aluminum trichloride into the reaction kettle, mixing, cooling to 45 ℃, reacting for 6 hours, and reducing side reactions to obtain methyl dichlorochrysanthemate;

4) cooling, and distilling under reduced pressure to remove the organic solvent to obtain a reaction product;

5) adding the reaction product obtained in the step 4) into a reaction kettle, simultaneously adding liquid alkali and absolute ethyl alcohol, heating and refluxing for 2 hours, and distilling at normal pressure to recover methanol and ethanol to obtain sodium dichlorochrysanthemate;

6) adding toluene and hydrochloric acid into a reaction kettle, controlling the pH value to be 1-2, acidifying for 0.5h, standing and layering;

7) and (4) taking the oil layer, and evaporating water and toluene to obtain the DV-chrysanthemic acid product.

The reaction principle has the chemical formula as follows:

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(retrieving that the prior art describes a method for synthesizing DV-chrysanthemic acid by isoamylene alcohol and carbon tetrachloride, which is close to the scheme of the patent, and is different from the scheme of the patent, and does not describe the use of ethyl trivinyl ether; please confirm whether ethyl trivinyl ether is a raw material or additive conventionally used in the field, and if not, preferably supplement what effect is brought about by selecting the substance as an intermediate or catalyst compared with the prior art so as to enhance the creativity of the patent)

Compared with the prior art, the invention has the advantages that:

1) the reaction temperature and time are controlled to ensure the complete reaction process and effectively reduce the occurrence of side reactions;

2) the content of DV-chrysanthemic acid in the prepared product is increased to 99.2%, and the yield is increased to 87%;

3) the preparation method is safe, environment-friendly, simple in steps, easy to popularize, suitable for large-scale industrial production and wide in application prospect.

Detailed Description

The technical scheme of the invention is further illustrated by the following examples. The technical solutions and resulting parameters given in the following examples are only exemplary and are intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

Adding 86g of isopentenol into a 500ml four-neck flask, introducing a little hydrogen chloride to adjust the isopentenol to be acidic, slowly dropwise adding 175g of ethyl trivinyl ether, and controlling the dropwise adding temperature to be not more than 30 ℃; after the dropwise addition is finished, heating to 105 ℃, and carrying out heat preservation reaction for 4 hours; continuously adding 100mL of carbon tetrachloride, 50mL of isopropanol and 133g of aluminum trichloride into the reaction kettle, mixing, and cooling to 45 ℃ for reaction for 6 hours; cooling, distilling under reduced pressure to remove organic solvent, adding 133g of liquid alkali and 46g of absolute ethyl alcohol into the reaction kettle, heating and refluxing for 2h, and distilling at normal pressure to recover methanol and ethanol; adding 100mL of toluene and 98.6g of 37% hydrochloric acid into a reaction kettle, acidifying for 0.5h, standing and layering; the oil layer was taken and water and toluene were distilled off to obtain 184.5g of DV-chrysanthemic acid product. The content of DV-chrysanthemic acid in the product is 99.2% and the yield is 87.5% through detection and analysis.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.