Pyrethroid compounds containing double bonds and cyano groups, their synthesis methods and applications

Abstract

The present invention discloses a pyrethroid compound having a double bond containing a cyano group, a synthesis method and applications. When synthesizing, tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate and cyanomethyl phosphate are used as raw materials. Through the Witting-Horner reaction and column chromatography separation, tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate is obtained. After deprotection, (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid is obtained. Through an acyl group chlorination reaction, (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropane acid chloride is generated, and further esterification with the corresponding alcohol gives a pyrethroid compound. The said compound is used as an insecticide to kill pests such as mosquitoes, flies, and cockroaches.

Description

Technical Field

[0001] The present invention relates to pyrethroid compounds that can be used for insecticidal purposes, specifically to a method for synthesizing pyrethroid compounds containing double bonds and cyano groups, and their application in controlling pests such as mosquitoes and flies. It belongs to the field of chemical synthesis technology.

Background Art

[0002] Pyrethroids are the active ingredients in mosquito coils and aerosol agents, and are mainly used for controlling household pests such as mosquitoes and flies. Due to the long-term use of pyrethroid products, mosquitoes have varying degrees of resistance to most commercially available products. The development of pyrethroids with new structures helps to partially solve the problem of resistance and extend the service life of this type of insecticide.

[0003] Momfluorothrin (US2012 / 29227, EP2241551) is a new pyrethroid insecticide developed by Sumitomo Corporation of Japan. It has good contact insecticidal effects on insects and spiders, but there are no reports on household pests. As a result of testing, it has good knockdown activity against mosquitoes as an aerosol agent in a cylinder, but it has been found that its activity as a mosquito coil is inferior. This may be because the presence of nitrogen in this structure reduces the vapor pressure, making it difficult to volatilize by heating to obtain a contact killing effect.

[0004] The present invention increases the vapor pressure of the compound by simplifying the structure of momfluorothrin, further enhances the effect as a mosquito coil, and lays the foundation for the application of pyrethroid compounds having a cyano group on the double bond in mosquito control.

Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a pyrethroid compound containing a double bond and a cyano group, a synthesis method thereof, and an application thereof, which are used as insecticides for controlling pests such as mosquitoes, flies, and German cockroaches in consideration of the disadvantages of the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solutions.

[0007] The present invention first provides a pyrethroid compound represented by the following general formula I:

Chemical formula

[0008] In the above aspect, when n is 3, the compound is 2,3,5-trifluorobenzyl (Z)-3-(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate or 2,3,6-trifluorobenzyl (Z)-3-(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate.

[0009] In the above aspect, when n is 4, the compound is 2,3,5,6-tetrafluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate.

[0010] In the above aspect, the compound is preferably 2,3,5-trifluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate, and its structural formula is shown in Formula II:

Chemical formula

[0011] The present invention also provides a synthesis method of the pyrethroid compound containing a double bond and a cyano group, which includes the following steps.

[0012] (1) Synthesis of Z-configuration product: React 3-formyl-2,2-dimethyl-cyclopropionic acid tert-butyl with cyanomethyl phosphate or cyanomethyl triphenylphosphine under the action of a base in Solvent I to produce tert-butyl 3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate, and obtain (Z)-tert-butyl 3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate by column chromatography;

[0013] (2) Debutylation Remove tert-butyl from (Z)-tert-butyl 3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate obtained in step (1) under the action of an acid to obtain (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid;

[0014] (3) Acyl chlorination reaction: Subject (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid obtained in step (2) to an acyl chlorination reaction to obtain (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride;

[0015] (4) Esterification reaction: Subject (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride obtained in step (3) and benzyl alcohol to an esterification reaction under the action of a base to obtain a pyrethroid compound containing a double bond and a cyano group.

[0016] The chemical reaction formula is as follows:

Chemical formula

[0017] In the above aspect, in step (1), for the synthesis of the Z-configuration product, the specific operation is as follows. Suspend a base in solvent I at -5 to -30°C, dropwise add cyanomethyl phosphate or cyanomethyl triphenylphosphine to the system at -5 to -30°C, and then dropwise add tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate; keep the temperature at -5 to -30°C for 1 hour, after confirming by GC analysis that the conversion of the raw materials is complete, neutralize the pH of the system to 7 to 8 with 10% hydrochloric acid, then separate the layers, extract the aqueous layer with an extraction solvent, and obtain an organic phase. The organic phase is desolvated and subjected to column chromatography to obtain tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate.

[0018] In the above aspect, in step (1), the cyanomethyl phosphate is dimethyl cyanomethyl phosphate, diethyl cyanomethyl phosphate, or isopropyl cyanomethyl phosphate, preferably dimethyl cyanomethyl phosphate.

[0019] In the above aspect, in step (1), the molar ratio of the cyanomethyl phosphate or cyanomethyl triphenylphosphine to tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate is 0.5 to 1.5:1.

[0020] In the above aspect, in step (1), the solvent I is any one of tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, and toluene, or a mixture of two or more of these in any ratio, preferably tetrahydrofuran; the solvent I is used in an amount 3 to 15 times the weight of tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate.

[0021] In the above aspect, in step (1), the base is any one of sodium methoxide, sodium ethoxide, sodium amide, sodium tert-butoxide, potassium tert-butoxide, or a mixture of two or more of these in any ratio; the base is used in an amount of 1 to 5 molar equivalents, preferably 1.2 molar equivalents, of cyanomethyl phosphate or cyanomethyltriphenylphosphine.

[0022] In the above aspect, in step (1), the extraction solvent is any one of ethyl acetate, methyl acetate, dichloromethane, dichloroethane, chloroform, toluene, xylene, benzene, or a mixture of two or more of these in any ratio, with ethyl acetate being preferred. The extraction solvent is 1 to 5 times the weight of tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate.

[0023] In the above aspect, in step (2), for the removal of the tert-butyl group, the specific operation is as follows. Dissolve tert-butyl Z-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate in solvent II and react it at the normal pressure reflux temperature (61 - 140 °C) of the reaction solvent used under the catalytic action of an acid to remove the tert-butyl group. After confirming the completion of the conversion of the raw material by TLC, wash with water to pH 6 - 7 after the system has cooled down, and remove the solvent to obtain (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid.

[0024] In the above aspect, in step (2), the solvent II is any one of toluene, xylene, benzene, dichloroethane, chloroform, tetrahydrofuran, or a mixture of two or more of these in any ratio, with toluene being preferred; the solvent II is used in an amount of 3 to 10 times the weight of tert-butyl Z-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate.

[0025] In the above aspect, in step (2), the acid is any one of p-toluenesulfonic acid, methanesulfonic acid, hydrochloric acid, and hydrobromic acid, or a mixture obtained by mixing two or more of these in any ratio, and p-toluenesulfonic acid is preferred; the amount of the acid used is 0.01 to 1 molar equivalent of t-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate, preferably 0.03 molar equivalent.

[0026] In the above aspect, in step (3), for the acyl chlorination reaction, the specific operation is as follows. Dissolve Z-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid in solvent III, heat it to the normal pressure reflux temperature (39 - 140 °C) of the reaction solvent used, and drop thionyl chloride while refluxing. After the dropping is completed, keep it warm at 10 - 60 °C for 0.5 - 2 hours. After completely converting the raw materials in the gas phase, remove the solvent to obtain (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride.

[0027] In the above aspect, in step (3), the solvent III is any one of n-hexane, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, and xylene, or a mixture obtained by mixing two or more of these in any ratio, and n-hexane is preferred; the solvent III is used in an amount 3 to 10 times the weight of Z-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid.

[0028] In the above aspect, in step (3), the thionyl chloride is used in an amount of 1 to 3 molar equivalents of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid, preferably 1.2 molar equivalents.

[0029] In the above aspect, in step (4), for the esterification reaction, the specific operation is as follows. After dissolving benzyl alcohol in toluene, an acid binding agent is added, and (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride is added dropwise under the condition of 0 to 10 °C. After the addition is completed, the mixture is kept warm for 0.5 to 2 hours under the condition of 0 to 10 °C. After completely converting benzyl alcohol in the gas phase, the pH of the system is neutralized to 6 to 7 with dilute hydrochloric acid and then separated into layers. The organic phase is subjected to solvent removal, column chromatography separation, and solvent removal to obtain a pyrethroid compound containing a double bond and a cyano group.

[0030] In the above aspect, in step (4), the benzyl alcohol is 2,3,6-trifluorobenzyl alcohol, 2,3,5-trifluorobenzyl alcohol or 2,3,5,6-tetrafluorobenzyl alcohol.

[0031] In the above aspect, in step (4), the acid binding agent is triethylamine, pyridine or a liquid base (aqueous sodium hydroxide solution).

[0032] In the above aspect, in step (4), the molar ratio of the benzyl alcohol, the acid binding agent, and (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride is 0.9 to 1.2:1.0 to 1.3:1.

[0033] In the above aspect, in step (4), the toluene is used in an amount of 3 to 10 times the weight of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride.

[0034] The present invention also provides an application of using the pyrethroid compound containing a double bond and a cyano group as an insecticide for controlling pests.

[0035] In the above aspect, when the pyrethroid compound containing a double bond and a cyano group is used as an insecticide for pest control, the pyrethroid compound containing a double bond and a cyano group represented by Formula I is used as a mosquito repellent aerosol (content 0.3%) or an electric mosquito coil (content 0.04%) and is used for killing mosquitoes, flies, German cockroaches, etc.

[0036] Compared with the prior art, the present invention provides a pyrethroid compound having a novel structure. The pyrethroid compound is slightly toxic to mammals. For example, the median lethal dose (LD50) of the acute oral toxicity of 2,3,5,6-tetrafluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate, which is a compound of the present invention, in rats exceeds 5000 mg / kg and is slightly toxic; the median lethal dose (LD50) of the acute dermal toxicity in rats exceeds 5000 mg / kg and is slightly toxic. It is significantly lower than the acute toxicity of Dimefluthrin and Metofluthrin commonly seen in the market at present, is safer for non-target organisms, and has a very excellent preventive effect on some specific pest targets. In addition, it has the characteristic of high vapor pressure and is suitable for various dosage forms of room temperature volatile hygiene preparations.

Embodiments for Carrying Out the Invention

[0037] The specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following description.

[0038] The raw materials in the examples of the present invention, such as tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate, cyanomethyl phosphate or cyanomethyl triphenylphosphine, 2,3,6-trifluorobenzyl alcohol, 2,3,5-trifluorobenzyl alcohol, 2,3,5,6-tetrafluorobenzyl alcohol, and monofluorotrin, can be purchased.

Examples

[0039] Hereinafter, the present invention will be described based on specific examples.

[0040] Example 1: (1) Synthesis of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate To a 250 mL four-necked flask equipped with stirring, add 3.51 g (90 mmol) of sodium amide and 80 mL of tetrahydrofuran, stir and cool to -20 °C, dropwise add 6.7 g (45 mmol) of dimethyl cyanomethylphosphonate. After the addition is complete, stir for 15 minutes. At this temperature, dropwise add 8 g (40 mmol) of tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate. After the addition is complete, keep the temperature for 0.5 hour. After complete conversion of tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate in the gas phase, dropwise add 5% hydrochloric acid until the pH of the system reaches 7-8, separate the layers, extract the aqueous layer with 2 * 20 mL of ethyl acetate, combine the organic phases and remove the solvent to recover 8 g of a brown liquid. Use column chromatography with ethyl acetate:n-hexane = 1:10 (V / V) to obtain 4.32 g of a white solid of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate (yield = 54%).

[0041] (2) Synthesis of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid To a 250 mL four-necked flask equipped with stirring, add 4.32 g (19.5 mmol) of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate, 0.13 g of p-toluenesulfonic acid and 25 mL of toluene, stir, heat to reflux at 110 °C, and react for 1.5 hours while refluxing. Monitor the reaction by TLC. After the raw materials are completely converted, cool to room temperature, wash with water until the pH of the system reaches 6-7, remove the solvent to obtain 3 g of a pale yellow solid of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid (yield = 93%).

[0042] (3) Synthesis of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride Add 3 g (18.2 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid and 20 mL of n-hexane to a 250 mL four-necked flask equipped with stirring. Add 2 drops of DMF, stir, heat to reflux, and add 2.6 g (21.8 mmol) of thionyl chloride dropwise. After the addition is complete, keep warm for 0.5 h. After the raw materials are completely converted in the gas phase, remove the solvent to obtain 3.2 g (17.5 mmol) of a dark green oily liquid of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride (yield = 96%).

[0043] (4) Synthesis of 2,3,5-trifluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate Add 2.7 g (16.7 mmol) of 2,3,5-trifluorobenzyl alcohol, 4.7 g (35 mmol) of 30% aqueous sodium hydroxide solution, and 20 mL of toluene to a 250 mL four-necked flask. Stir and cool to 0 - 5 °C. Slowly add 3.2 g (17.5 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride dropwise. After the addition is complete, keep warm. After the benzyl alcohol is completely converted in the gas phase, adjust the pH to 6 - 7 with hydrochloric acid, separate the layers, remove the solvent from the organic phase, and separate by column chromatography using ethyl acetate:n-hexane = 1:15 (V / V). Remove the solvent to obtain 4.7 g of a colorless oily liquid of 2,3,5-trifluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate (yield = 92%).

[0044] Example 2: (1) Synthesis of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate To a 250 mL four-necked flask equipped with stirring, add 6.8 g (100 mmol) of sodium ethoxide and 50 mL of tetrahydrofuran, stir and cool to -20 °C. Then, dropwise add 8.95 g (50 mmol) of diethyl cyanomethylphosphonate. After the addition is complete, stir for 15 minutes. At this temperature, dropwise add 9 g (45 mmol) of tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate. After the addition is complete, keep the temperature for 0.5 hour. After completely converting tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate in the gas phase, dropwise add 5% hydrochloric acid until the pH of the system reaches 7-8. Separate the layers, extract the aqueous layer with 2 * 20 mL of ethyl acetate, combine the organic phases and remove the solvent to recover 9.5 g of a brown liquid. Use column chromatography with ethyl acetate:n-hexane = 1:10 (V / V) to obtain 5.17 g of white solid of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate (yield = 52%).

[0045] (2) Synthesis of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid Add 5.17 g (23.4 mmol) of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate, 0.16 g of p-toluenesulfonic acid and 25 mL of dichloroethane to a 250 mL four-necked flask equipped with stirring, stir and heat to reflux at 84 °C, and react for 6 hours while refluxing. Monitor the reaction by TLC. After the raw material is completely converted, cool to room temperature, wash with water until the pH of the system reaches 6-7, and remove the solvent to obtain 3.7 g of light yellow solid of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid (yield = 96%).

[0046] (3) Synthesis of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride Add 3.7 g (22.4 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid and 20 mL of dichloromethane to a 250 mL four-necked flask equipped with stirring. Add 2 drops of DMF, stir, heat to reflux at 40 °C, and dropwise add 3.2 g (26.9 mmol) of thionyl chloride. After the addition is complete, keep warm for 0.5 h. After completely converting the raw materials in the gas phase, remove the solvent to obtain 4.16 g (20.8 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride as a dark green oily liquid (yield = 93%).

[0047] (4) Synthesis of 2,3,6-trifluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate Add 3.0 g (18.7 mmol) of 2,3,6-trifluorobenzyl alcohol, 2.95 g (37.4 mmol) of pyridine, and 20 mL of toluene to a 250 mL four-necked flask. Stir and cool to 0 - 5 °C. Slowly dropwise add 4.16 g (20.8 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride. After the addition is complete, keep warm. After completely converting the benzyl alcohol in the gas phase, adjust the pH to 6 - 7 with hydrochloric acid, separate the layers, remove the solvent from the organic phase, and separate by column chromatography using ethyl acetate:n-hexane = 1:15 (V / V). Remove the solvent to obtain 5.14 g of a colorless oily liquid of 2,3,6-trifluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate (yield = 89%).

[0048] Example 3: (1) Synthesis of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate Into a 250 mL four-necked flask equipped with stirring, 4.86 g (90 mmol) of sodium methoxide and 60 mL of acetonitrile were added. After stirring and cooling to -20 °C, 6.7 g (45 mmol) of dimethyl cyanomethylphosphonate was added dropwise. After the addition was complete, stirring was carried out for 15 minutes. At this temperature, 8 g (40 mmol) of tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate was added dropwise. After the addition was complete, the temperature was maintained for 0.5 hour. After completely converting tert-butyl 3-formyl-2,2-dimethyl-cyclopropionate in the gas phase, 5% hydrochloric acid was added dropwise until the pH of the system reached 7 - 8. Liquid separation was carried out, and the aqueous layer was extracted with 2 * 20 mL of ethyl acetate. The organic phases were combined and the solvent was removed, and 8.4 g of a brown liquid was recovered. 5.22 g of a white solid of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate was obtained by column chromatography using ethyl acetate:n-hexane = 1:10 (V / V) (yield = 59%).

[0049] (2) Synthesis of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid Into a 250 mL four-necked flask equipped with stirring, 5.22 g (23.6 mmol) of tert-butyl (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionate, 0.16 g of p-toluenesulfonic acid and 30 mL of xylene were added. After stirring, the temperature was raised to 140 °C for reflux, and the reaction was carried out under reflux for 2 hours. The reaction was monitored by TLC. After the raw material was completely converted, it was cooled to room temperature, washed with water until the pH of the system reached 6 - 7, and the solvent was removed to obtain 3.66 g of a pale yellow solid of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid (yield = 94%).

[0050] (3) Synthesis of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride Add 3.66 g (22.2 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid and 20 mL of cyclohexane to a 250 mL four-necked flask equipped with stirring, add 2 drops of DMF, stir, heat to reflux at 81 °C, and dropwise add 3.96 g (33.3 mmol) of thionyl chloride. After the addition is complete, keep the temperature for 0.5 hour. After completely converting the raw materials in the gas phase, remove the solvent to obtain a dark green oily liquid of 4.34 g (21.76 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride (yield = 98%).

[0051] (4) Synthesis of 2,3,5,6-tetrafluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate Add 3.33 g (18.5 mmol) of 2,3,5,6-tetrafluorobenzyl alcohol, 4.7 g (35 mmol) of 30% aqueous sodium hydroxide solution, and 20 mL of toluene to a 250 mL four-necked flask. Stir and cool to 0 - 5 °C. Slowly dropwise add 4.34 g (21.76 mmol) of (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride. After the addition is complete, keep the temperature. After completely converting benzyl alcohol in the gas phase, adjust the pH to 6 - 7 with hydrochloric acid, separate the layers, remove the solvent from the organic phase, and separate by column chromatography using ethyl acetate:n-hexane = 1:20 (V / V). Remove the solvent to obtain 5.32 g of a colorless oily liquid of 2,3,5,6-tetrafluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate (yield = 88%).

[0052] According to the synthesis methods of Examples 1 - 3, pyrethroid compounds 1 - 3 containing a double bond and a cyano group of the present invention were produced, and their structural formulas are shown in Formula I. [Chemical formula] Formula I In the formula, n is 3 or 4. [Table 1]

[0053] The following test examples demonstrated that the pyrethroid compounds of the present invention are effective as pest control agents.

[0054] Test Example 1: 120 parts by mass of water was added to 99.96 parts by weight of corn starch, a mixture of carbon powder and wood powder (1:5:4), kneaded and molded, and dried to form a mosquito-repellent incense base material (diameter 12.0 cm, thickness 4 mm, pair weight 40 g).

[0055] On the other hand, a 0.4 w / v% solution of Compound 1 in kerosene was prepared. After uniformly spray-applying 4 ml of this solution to the mosquito-repellent incense base material using a microsyringe, it was left to stand at room temperature for 3 hours and dried to obtain one set of mosquito-repellent incense W1 containing 0.04 w / w% Compound 1.

[0056] Similarly, Compounds 2 - 3 of the present invention in Table 1, as well as transfluthrin and tetramethylfluthrin, were each prepared to obtain the corresponding mosquito-repellent incenses W2 - W5.

[0057] The mosquito-repellent effects of mosquito-repellent incenses W1 - W5 were measured and compared with reference to GB / T13917.4 - 2009. The test insects were female mosquitoes of Aedes aegypti that had not sucked blood 2 - 3 days after emergence. The specific process was as follows. Using a mosquito-catching tube, 20 test mosquitoes were captured and placed in a sealed cylindrical test device. Any part of the test mosquito-repellent incense was taken, placed on an incense rack, ignited and timed. After 1 minute, the mosquito-repellent incense was moved, and the number of test mosquitoes knocked down at regular intervals was recorded. The experimental results are shown in Table 2. The mosquito-repellent efficacy of the mosquito-repellent incenses produced by Compounds 1 - 3 of the present invention, which were synthesized by simplifying the transfluthrin structure, was significantly superior to that of transfluthrin and was also significantly superior to that of tetramethyl ether, a commercialized pyrethroid of the control compound.

Table 2

[0058] Test Example 2: After uniformly heating and mixing 0.3 parts by weight of Compound 1 and 59.7 parts by weight of kerosene, an insecticide was prepared. The obtained preparation was placed in an aerosol tank, and a valve was attached to the tank. 40.0 parts by weight of propane and butane were injected through this valve under pressure to obtain an insecticidal aerosol agent containing 0.3% of Compound 1.

[0059] The efficacy of this insecticidal aerosol agent against mosquitoes, flies, and German cockroaches was measured according to GB / T13917.2 - 2009, and a sealed cylinder device was adopted. The specific process is as follows. Test insects were placed in a tank. After the test insects recovered to normal activity, 1 g of the agent was quantitatively injected from the insecticidal aerosol agent tank. After 1 minute, the baffle was extracted to bring the test insects into contact with the agent, and timing was started immediately, and recording was started. The number of test insects knocked down at regular intervals was recorded. After 20 minutes, all the test insects were transferred to a clean insect rearing cage, and the number of dead test insects was examined 24 hours later. Among them, the 72 - hour mortality rate of German cockroaches was examined.

[0060] According to Test Example 2, aerosol agents of Compounds 1 - 3, transfluthrin, and tetramethylfluthrin were prepared respectively and subjected to efficacy tests. The comparison results are shown in Table 3.

Table 3

[0061] As is clear from the results, the aerosol agent prepared with Compound 1 of the present invention has a relatively good control effect against mosquitoes, flies, and German cockroaches, and its effect is clearly better than that of other compounds.

[0062] The above examples are for explaining the technical concept and technical features of the present invention, and do not limit the protection scope of the present invention thereby. Equivalent conversions or modifications made based on the essence of the present invention should be included within the protection scope of the present invention.

Claims

1. The general structural formula of the pyrethroid compound is Formula I: I; n is 3 or 4.

2. When n is 3, the compound is 2,3,5-trifluorobenzyl (Z)-3-(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate or 2,3. 6-trifluorobenzyl (Z)-3-(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate. The pyrethroid compound according to Claim 1, characterized in that it is.

3. When n is 4, the pyrethroid compound according to Claim 1, characterized in that it is 2,3,5,6-tetrafluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate.

4. The pyrethroid compound according to Claim 1, characterized in that the compound is 2,3,5-trifluorobenzyl (Z)-3(2-cyanovinyl)-2,2-dimethylcyclopropanecarboxylate and the structural formula is represented by Formula II. II.

5. A method for synthesizing a pyrethroid compound having a cyano group at a double bond according to any one of Claims 1 to 4, characterized by including the following steps. (1) Synthesis of the Z-configuration product: 3-Formyl-2,2-dimethyl-cyclopropionic acid tert-butyl ester is reacted with cyanomethylphosphoric acid or cyanomethyltriphenylphosphine in Solvent I with an alkali to produce 3-(2-cyanovinyl)-2,2-dimethyl-tert-butylcyclopropionate. By chromatography, (Z)-3-(2-cyanovinyl)-2,2-dimethyl-tert-butyl cipionate is obtained. (2) Remove tert-butyl. The (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid tert-butyl ester obtained in Step (1) becomes a de-tert-butyl ester under the action of an acid to obtain (Z)-3. -(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid; (3) Acid chlorination reaction: The (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid obtained in Step (2) is subjected to an acid chlorination reaction to obtain (Z)-3-(2-cyanovinyl)-2, 2-dimethylcyclopropionyl chloride; (4) Esterification reaction: The (Z)-3-(2-cyanovinyl)-2,2-dimethylcyclopropionyl chloride obtained in step (3) is esterified with benzyl alcohol under the action of an alkali to obtain a cyanide group-containing bispyrethroid compound.

6. In step (1), the synthesis method according to claim 5, characterized in that an alkali is suspended in solvent I at -5 to -30 °C, and a base is suspended in solvent I at -5 to -30 °C. C. First, cyanomethylphosphoric acid or cyanomethyltriphenylphosphine is dropped, and then tert-butyl 3-formyl-2,2-dimethylcyclopropionate is dropped to obtain (Z)-3-(2-cyanovinyl). -2,2-dimethyl-tert-butyl cyclopropionate; Solvent I is any one or two of tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, toluene, and a mixture of these in any ratio.

7. (2) The synthesis method according to claim 5, characterized in that Z-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid tert-butyl ester is dissolved in solvent II and carried out under the reaction conditions. By the catalytic action of an acid, (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionic acid is obtained; Solvent II is any one or a mixture of two or more of toluene, xylene, benzene, dichloroethane, chloroform, and tetrahydrofuran in any ratio.

8. (3) The synthesis method according to claim 5, characterized in that Z-3-(2-cyanovinyl)-2,2-dimethylcyclopropionic acid is dissolved in solvent III, and thionyl chloride is dropped under normal pressure reflux. And react to obtain (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride; Solvent III is any one of n-hexane, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, or a mixture of two or more of them in any ratio.

9. In step (4), after dissolving benzyl alcohol in toluene, an acid binder is added and reacted with (Z)-3-(2-cyanovinyl)-2,2-dimethyl-cyclopropionyl chloride to obtain a cyano-containing double bond pyrethroid compound of formula I, characterized in that the acid binder is triethylamine, pyridine or liquid caustic soda; the synthesis method according to claim 5.

10. Use of the double bond cyano group-containing pyrethroid compound according to any one of claims 1 to 4 as an insecticide for the prevention and control of sanitary pests. A scented aerosol or electric mosquito-repellent incense used to kill mosquitoes, flies and cockroaches.

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