Application of 4, 5, 6, 7-tetrahydrobenzothiophene compound in pest control

Abstract

The invention provides an application of a 4, 5, 6, 7-tetrahydrobenzothiophene compound in pest control. According to the present invention, the compound provides significant insecticidal activity for Ostrinia furnacalis (Ostrinia furnacalis), Plutella xylostella (Plutella xylostella), Mythimna separia (Mythimna separia), Helicoverpa armigera (Helicoverpa armigera), Aphis gossypii (Apis gossypii), Tetranychus cinnabarinus), and sanitary pests, such as culex pipiens pallens, and can be used for the preparation of the compound, such that the compound has significant insecticidal activity, and can be used for the preparation of the drug for preventing and treating the diseases such as the insect pests, such as the insect pests such as the culex pipiens pallens, and the like. Besides, the compound is simple in structure, easy to synthesize and low in cost, provides a new effective strategy for green control of agricultural pests and sanitary pests, and has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and specifically relates to application of 4,5,6,7-tetrahydrobenzothiophene compounds in pest control, and more specifically relates to application of 4,5,6,7-tetrahydrobenzothiophene compounds in control of agricultural pests such as Ostriniafurnacalis, Plutella xylostella, Mythimna separata, Helicoverpa armigera, Aphis gossypii, Tetranychus cinnabarinus, and sanitary pests such as Culex pipiens pallens. Background Art

[0002] Pest control has always been a vital part of agricultural production and human life. Pests not only cause a significant decline in crop yields, affecting crop quality and the market value of agricultural products, but can also act as a vector of transmission, threatening human health. Common agricultural pests, such as the Asian corn borer (Ostrinia furnacalis), the diamondback moth (Plutella xylostella), the armyworm (Mythimna separata) and the cotton bollworm (Helicoverpa armigera), feed on plant leaves and inhibit the normal growth of plants. [1] Piercing-sucking pests such as cotton aphids (Aphis gossypii) and spider mites (Tetranychus cinnabarinus) suck the sap from leaves, causing the leaves to dry and curl, seriously hindering plant photosynthesis and thus reducing the quality of agricultural products. [2] In addition, common health pests, such as Culex pipiens pallens, are the most important mosquito threat in northern China and are also important vectors of Bancroftian filariasis and West Nile virus, posing a great threat to human life and health. [3] .

[0003] At present, the control of agricultural and health pests still relies on traditional chemical pesticides, but these traditional chemical pesticides have a lot of problems, such as the rapid development of drug resistance. [4] , serious environmental pollution [5] and toxicity to non-target organisms [6]In order to solve these problems, it is particularly urgent to develop new, environmentally friendly and highly effective pesticide-killing agricultural chemicals. In previous studies, we found that 4,5,6,7-tetrahydrobenzothiophene compounds are a class of compounds with novel skeletons, simple structures, and easy synthesis, and have excellent chitin hydrolase inhibitory activity. [7-9] Chitin hydrolase is a key enzyme related to insect molting development. It has the advantages of high efficiency and high selectivity and is an important target for pest control.

[0004] References

[0005] [1]Dwisandi RF, Miranti M, Prismantoro D, et al. Trichoderma formanaging lepidopteran insect pests: current understanding and future directions[J]. Biological Control, 2024,197:105604.

[0006] [2] Cui Shufang, Li Junlan, Jin Weiping, et al. Occurrence, damage and control of cotton aphids[J]. China Cotton, 2010, 37(4): 33-34.

[0007] [3]Liu M, Zhang Y, Li Q, et al. Spatial distribution and environmental correlations of culex pipiens pallens (diptera: culicidae) in haidian district, beijing[J]. Journal of Medical Entomology, 2024, 61(4):948-958.

[0008] [4] Liu H, Xie L, Cheng P, et al. Trends in insecticide resistance in Culexpipiens pallens over 20years in Shandong, China[J]. Parasites and Vectors, 2019, 12(1):167.

[0009] [5]Ahmad M F,Ahmad F A,Alsayegh AA,et al.Pesticides impacts on humanhealth and the environment with their mechanisms of action and possiblecountermeasures[J].Heliyon,2024,10(7):e29128.

[0010] [6]Henry M,Béguin M,Requier F,et al.A common pesticide decreasesforaging success and survival in honey bees[J].Science,2012.

[0011] [7]Dong Y,Hu S,Zhao X,et al.Virtual screening,synthesis,andbioactivity evaluation for the discovery ofβ-N-acetyl-D-hexosaminidaseinhibitors[J].Pest Management Science,2020,76(9):3030-3037.

[0012] [8]Dong Y,Jiang X,Liu T,et al.Structure-Based Virtual Screening,Compound Synthesis,and Bioassay for the Design of Chitinase Inhibitors[J].Journal of Agricultural and Food Chemistry,2018,66(13):3351-3357.

[0013] [9]Dong Y,Hu S,Jiang X,et al.Pocket-based Lead Optimization Strategyfor the Design and Synthesis of Chitinase Inhibitors[J].Journal ofAgricultural and Food Chemistry,2019,67(13):3575-3582. Summary of the invention

[0014] The purpose of the present invention is to provide application of 4,5,6,7-tetrahydrobenzothiophene compounds in pest control.

[0015] The 4,5,6,7-tetrahydrobenzothiophene compound has a structural formula as shown in Formula I:

[0016]

[0017] In Formula I, R 1 At least one selected from: H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted C1-C8 alkoxy, and substituted or unsubstituted C6-C15 aryl;

[0018] L is selected from at least one of an ester group, an amide group, a urea group, a substituted or unsubstituted C1-C5 alkylene group, and a substituted or unsubstituted C1-C5 heteroalkylene group; or -LR 2 For -NH 2 ;

[0019] R 2 At least one selected from: substituted or unsubstituted C1-C10 straight-chain alkyl, substituted or unsubstituted C3-C10 branched-chain alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C3-C10 heterocycloalkyl, C6-C30 aryl-substituted amino, C1-C10 alkyl-substituted amino, C1-C10 alkoxy, C2-C10 substituted or unsubstituted alkenyl;

[0020] R 3 Selected from: hydrogen, cyano, carboxyl, R 3-1 CONHCH 2 -、R 3-2 OCO-, R 3-1 At least one of the following, wherein the R 3-1 is a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C2-C8 branched-chain alkyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C5-C30 heteroaryl group; R 3-2 is a substituted or unsubstituted C1-C8 straight-chain alkyl group or a substituted or unsubstituted C3-C8 branched-chain alkyl group;

[0021] X is selected from: -CH 2 - or -NH-;

[0022] The R1 In the substituted C1-C8 alkyl group and the substituted C1-C8 alkoxy group, the substituent is a halogen or a C6-C15 aryl group;

[0023] The substituent in the substituted C6-C15 aryl group is halogen, nitro, C1-C5 alkyl or C1-C5 alkoxy;

[0024] The R 2 In the substituted C1-C10 straight-chain alkyl group, the substituent is a halogen, a carboxyl group, a C1-C5 alkylamino group, a C3-C8 cycloalkyl group, a C3-C12 heterocycloalkyl group, a C6-C20 aryl-substituted mercapto group, a C6-C20 aryl group, or a C5-C15 heteroaryl group;

[0025] The substituent in the substituted C3-C8 branched alkyl group is halogen, carboxyl, C1-C5 alkylamino, C3-C8 cycloalkyl, C3-C12 heterocycloalkyl, C6-C20 aryl or C5-C15 heteroaryl;

[0026] The substituent in the substituted C6-C30 aryl group is halogen, carboxyl, nitro, cyano, C1-C6 alkyl, C1-C6 alkoxy, halogen-substituted C1-C6 alkyl, C6-C20 aryloxy, or C5-C10 heteroalkyl or heteroaryl connected to the aryl group in parallel or through a single bond or double bond;

[0027] The substituent in the substituted C5-C30 heteroaryl is halogen, carboxyl, nitro, C1-C6 alkoxy, C6-C15 aryl, C1-C6 alkyl, halogen-substituted C1-C6 alkyl or C5-C15 heteroaryl;

[0028] The substituents in the substituted C3-C10 cycloalkyl are halogen, C3-C8 cycloalkyl, alkenyl (such as -CH=C(Cl)-CF 3 ), C1-C6 alkyl, C6-C20 aryl or C5-C15 heteroaryl;

[0029] The substituent in the substituted C3-C10 heterocycloalkyl is halogen, C3-C8 cycloalkyl, C6-C20 aryl, C1-C6 alkyl or C5-C15 heteroaryl;

[0030] The substituent in the substituted C2-C10 alkenyl group is a C6-C20 aryl group;

[0031] R 3-1wherein the substituents of the substituted C1-C8 straight-chain alkyl, substituted C2-C8 branched-chain alkyl, substituted C6-C30 aryl, and substituted C5-C30 heteroaryl are halogen, hydroxy, C3-C8 cycloalkyl, C6-C20 aryl or substituted C6-C20 aryl, C5-C15 heteroaryl or substituted C5-C15 heteroaryl, wherein the substituents are selected from halogen, hydroxy, C1-C6 alkyl, and C3-C8 cycloalkyl;

[0032] R 3-2 In the above, the substituent of the substituted C1~C8 straight-chain alkyl or the substituted C3~C8 branched-chain alkyl is halogen, C3~C8 cycloalkyl, C6~C20 aryl or substituted C6~C20 aryl, C5~C15 heteroaryl or substituted C5~C15 heteroaryl, wherein the substituent is selected from halogen, hydroxyl, C1~C6 alkyl and C3~C8 cycloalkyl.

[0033] The 4,5,6,7-tetrahydrobenzothiophene compound represented by the above formula I is selected from any one of the compounds in Table 1:

[0034] Table 1

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] The application of the 4,5,6,7-tetrahydrobenzothiophene compounds shown in the above formula I in agricultural and sanitary pest control also falls within the protection scope of the present invention.

[0053] In the application, the agricultural pests include Ostrinia furnacalis, Plutella xylostella, Mythimna separata, Helicoverpa armigera, Aphis gossypii and Tetranychus cinnabarinus;

[0054] The sanitary pests include Culex pipiens pallens.

[0055] The invention also provides an insecticide.

[0056] The insecticide provided by the present invention has an active ingredient of the 4,5,6,7-tetrahydrobenzothiophene compound shown in the above formula I, and its dosage form is a pharmacologically acceptable dosage form, including at least one of emulsifiable concentrate, wettable powder, suspension, dust, soluble powder, aqueous solution, water-dispersible powder, smoke agent, granule and seed coating agent.

[0057] The present invention has experimentally found that 4,5,6,7-tetrahydrobenzothiophene compounds are potential insecticidal compounds and show excellent application prospects. Exploring their application in agricultural and sanitary pest control can not only provide new solutions for agricultural production, but also promote the research and application of environmentally friendly pesticides. DETAILED DESCRIPTION

[0058] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0059] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0060] Preparation of Compounds of Formula I

[0061] The compounds of formula I provided by the present invention are prepared according to the following synthetic route:

[0062] Among them, Compounds H-1 to H-3, H-57 to H-98 are obtained by purchase.

[0063] Compounds H-4 to H-10, H11 to H56, H-99 to H-100, D-12, Q-1 to Q-35 are synthesized according to the following synthetic route:

[0064]

[0065] Synthetic Route of Compounds H-4 to H-9, H-11 to H-56, H-99 to H-100, D-12, Q-1 to Q-35

[0066]

[0067] Compounds D-1 to D-11, D-13 to D-106 are synthesized according to the following synthetic route:

[0068]

[0069] Among them, Condition i is ethanol and morpholine, heating under reflux for 5 h; Condition ii is acetone, heating under reflux for 3 - 5 h. Example 1, General Screening of Insecticidal Activity of Compounds of Formula I

[0070] 1. Insecticidal Activity Test against Asian Corn Borer

[0071] The insecticidal activity test of Asian corn borer (Ostrinia furnacalis) was completed by the leaf dipping method. Briefly described as follows: The test compound was formulated into a test concentration of 500 mg / L with acetone and a Triton X-100 solution with a mass concentration of five ten-thousandths, and the amount of acetone used did not exceed 1 mL. Fresh corn leaves were placed in the compound solution of the configured concentration, and the leaves were completely wetted. After 3 - 5 s, they were taken out and dried until the leaf surface was dry. Each group of tests used 10 third-instar larvae of Asian corn borer, placed in a petri dish with a diameter of about 10 cm, and repeated three times. In the control group, the leaves were wetted with acetone and Triton X-100 solution, and the rest were set the same. Treated corn leaves were added once every 24 h, and the growth of Asian corn borer was observed after 72 h. The insect body was gently touched with a brush and did not move, which could be regarded as dead, and recorded. Finally, the corrected mortality was calculated:

[0072] Corrected Mortality (%) = ((T - C)) / (1 - C)×100

[0073] Wherein, T represents the mortality rate (%) of the experimental group; C represents the mortality rate (%) of the blank control group.

[0074] 2. Test of insecticidal activity against Plutella xylostella

[0075] The insecticidal activity test for Plutella xylostella was conducted by leaf dipping method, with fresh cabbage leaves and second-instar larvae of Plutella xylostella selected for testing. For other information, please refer to the introduction to the insecticidal activity test method for corn borer.

[0076] 3. Test of insecticidal activity of sticky insects

[0077] The insecticidal activity test for armyworm (Mythimna separata) adopts the leaf dipping method, and fresh corn leaves and third-instar larvae of armyworm are used for testing. For other information, please refer to the introduction of the insecticidal activity test method for corn borer.

[0078] 4. Insecticidal activity test on cotton bollworm

[0079] The insecticidal activity test for cotton bollworm (Helicoverpa armigera) adopts the leaf dipping method, and fresh corn leaves and third-instar larvae of cotton bollworm are used for testing. For other information, please refer to the introduction of the insecticidal activity test method for corn borer.

[0080] 5. Insecticidal activity test on cotton aphid

[0081] The test of insecticidal activity against cotton aphid (Aphis gossypii Glover) is briefly described as follows: the test compound is prepared with acetone and a Triton X-100 solution with a mass concentration of 5 parts per million to a test concentration of 500 mg L-1, and the amount of acetone used does not exceed 1 mL. Broad bean plants with no less than 60 cotton aphid nymphs are immersed in the test solution for 2 to 3 seconds, the plants are taken out to shake off the excess solution, inserted into a foam board, covered with a gauze cover and sealed, and the control group is soaked with acetone and Triton X-100 solution. The experimental group and the treatment group are placed in a standard treatment room, and the results are checked after 24 hours, and the corrected mortality rate is calculated.

[0082] 6. Insecticidal activity test of spider mites

[0083] The insecticidal activity test for spider mites (Tetranychus cinnabarinus) is briefly described as follows: The test compound is prepared with acetone and a Triton X-100 solution with a mass concentration of 500 mg / L, and the amount of acetone does not exceed 1 mL. Plants with no less than 60 spider mites are immersed in the solution for 5 seconds, the plants are removed, the solution is shaken off, and the plants are placed in a hydroponic tank. In the control group, the plants are soaked with acetone and Triton X-100 solution. The experimental group and the treatment group are placed in a standard treatment room, and the results are checked after 24 hours to calculate the corrected mortality rate.

[0084] 7. Insecticidal activity test on Culex pipiens larvae

[0085] The insecticidal activity test of Culex pipiens pallens is briefly described as follows: the test compound is prepared into a 1000 mg / L stock solution with acetone and a Triton X-100 solution with a mass concentration of 5 parts per million, and the amount of acetone does not exceed 1 mL. 1 mL of the stock solution is measured in a beaker, and 89 mL of distilled water and 10 mL of feeding solution are added to make the final concentration of the test compound 10 mg / L. 10 4th-instar Culex pipiens larvae are placed in the beaker, and 1 mL of distilled water is used instead of the test compound in the control group, and the rest of the settings are the same. The experimental group and the control group are placed in a standard treatment room, and the results are checked after pupation or death, and the corrected mortality rate is calculated.

[0086] Table 2 General screening of insecticidal activity of 4,5,6,7-tetrahydrobenzothiophene compounds (500 mg / L, 10 mg / L)

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] a The test concentration is 500mg / L

[0095] b The test concentration is 10mg / L

[0096] The results showed that when the test concentration was 500 mg / L (10 mg / L for Culex pipiens larvae), more than 82% of 4,5,6,7-tetrahydrobenzothiophene compounds had a mortality rate of more than 50% against at least one of the seven common pests, and more than 50% of the compounds showed more than 50% lethal activity against two or more pests, indicating that such compounds have certain application potential for pest control.

[0097] Example 2: Test of insecticidal activity at reduced concentrations of the compound of formula I

[0098] For a compound having 100% lethality to a certain pest at 500 mg / L (10 mg / L for Culex pipiens larvae), a decreasing concentration test is performed, and if the lethality is still 100% at the current concentration, the concentration is further reduced until the lethality is less than 100%. The experimental method for each test concentration is the same as that described in Example 1.

[0099] Table 3 Insecticidal activity test of 4,5,6,7-tetrahydrobenzothiophene compounds on armyworm, cotton bollworm and corn borer at reduced concentrations

[0100]

[0101]

[0102]

[0103] Table 4 Insecticidal activity test of 4,5,6,7-tetrahydrobenzothiophene compounds on cotton aphid, spider mite, diamondback moth and Culex pipiens pallens larvae at reduced concentrations

[0104]

[0105]

[0106]

[0107]

[0108] The results showed that when the test concentration was reduced, some 4,5,6,7-tetrahydrobenzothiophene compounds still had a high mortality rate against seven common pests. For example, compound D-63 still had a 100% mortality rate against armyworms at a concentration of 10 mg / L; compounds D-47, D-55, etc. still had a 100% mortality rate against corn borers at 200 mg / L; D-66, D-71, etc. still had a mortality rate of more than 70% against diamondback moths at 125 mg / L; and D-12 still had a 100% mortality rate against mosquito larvae at a concentration of 2 mg / L.

[0109] Example 3, LC of the compound of formula I50 Determination

[0110] For compounds that still maintain high insecticidal activity in the test of reduced concentration, further LC of the corresponding pests was performed. 50 Test, LC 50 In the test, five groups of test compound concentrations were set, and the test method for each group was the same as described above. The final results were calculated using SPSS software.

[0111] Table 5 LC of 4,5,6,7-tetrahydrobenzothiophene compounds in Plutella xylostella 50 Determination

[0112]

[0113] Table 6 LC of 4,5,6,7-tetrahydrobenzothiophene compounds in Ostrinia nubilalis 50 Determination

[0114]

[0115] The results showed that the LC50 of compound D-71 and compound D-66 were 25.358 mg / L and 87.380 mg / L, respectively, which had similar insecticidal activity to the commercial agent fenbufenozide (LC50 = 18.319 mg / L); the LC50 of compound D-47 and D-55 against corn borer reached 381.042 mg / L and 255.186 mg / L, respectively. The experimental results further confirmed that the 4,5,6,7-tetrahydrobenzothiophene compounds provided by the present invention have great application potential in pest control.

[0116] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, and without the need to carry out unnecessary experimental conditions, the present invention can be implemented in a wide range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principles of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including departure from the disclosed scope in the application, and changes made with conventional techniques known in the art.

Claims

1. Application of 4,5,6,7-tetrahydrobenzothiophene compounds in pest control.

2. The use according to claim 1, characterized in that: The 4,5,6,7-tetrahydrobenzothiophene compound has a structural formula as shown in Formula I: In formula I, R1 is selected from at least one of H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted C1-C8 alkoxy and substituted or unsubstituted C6-C15 aryl; L is selected from at least one of an ester group, an amide group, a urea group, a substituted or unsubstituted C1-C5 alkylene group, and a substituted or unsubstituted C1-C5 heteroalkylene group; or -L-R2 is -NH2; R2 is selected from at least one of substituted or unsubstituted C1-C10 straight-chain alkyl, substituted or unsubstituted C3-C10 branched-chain alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C3-C10 heterocycloalkyl, C6-C30 aryl-substituted amino, C1-C10 alkyl-substituted amino, C1-C10 alkoxy, and C2-C10 substituted or unsubstituted alkenyl; R3 is selected from: hydrogen, cyano, carboxyl, R 3-1 CONHCH2-, R 3-2 OCO-, R 3-1 At least one of the following, wherein the R 3-1 is a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C2-C8 branched-chain alkyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C5-C30 heteroaryl group; R 3-2 is a substituted or unsubstituted C1-C8 straight-chain alkyl group or a substituted or unsubstituted C3-C8 branched-chain alkyl group; X is selected from: -CH2- or -NH-.

3. The use according to claim 2, characterized in that: In the R1, the substituent in the substituted C1-C8 alkyl group or the substituted C1-C8 alkoxy group is a halogen or a C6-C15 aryl group; The substituent in the substituted C6-C15 aryl group is halogen, nitro, C1-C5 alkyl or C1-C5 alkoxy.

4. The use according to claim 2, characterized in that: In the R2, the substituent in the substituted C1-C10 straight-chain alkyl group is halogen, carboxyl, C1-C5 alkylamino, C3-C8 cycloalkyl, C3-C12 heterocycloalkyl, C6-C20 aryl-substituted mercapto, C6-C20 aryl or C5-C15 heteroaryl; The substituent in the substituted C3-C8 branched alkyl group is halogen, carboxyl, C1-C5 alkylamino, C3-C8 cycloalkyl, C3-C12 heterocycloalkyl, C6-C20 aryl or C5-C15 heteroaryl; The substituent in the substituted C6-C30 aryl group is halogen, carboxyl, nitro, cyano, C1-C6 alkyl, C1-C6 alkoxy, halogen-substituted C1-C6 alkyl, C6-C20 aryloxy, or C5-C10 heteroalkyl or heteroaryl connected to the aryl group in parallel or through a single bond or double bond; The substituent in the substituted C5-C30 heteroaryl is halogen, carboxyl, nitro, C1-C6 alkoxy, C6-C15 aryl, C1-C6 alkyl, halogen-substituted C1-C6 alkyl or C5-C15 heteroaryl; The substituent in the substituted C3-C10 cycloalkyl is halogen, C3-C8 cycloalkyl, alkenyl, C1-C6 alkyl, C6-C20 aryl or C5-C15 heteroaryl; The substituent in the substituted C3-C10 heterocycloalkyl is halogen, C3-C8 cycloalkyl, C6-C20 aryl, C1-C6 alkyl or C5-C15 heteroaryl; The substituent in the substituted C2-C10 alkenyl group is a C6-C20 aryl group.

5. The use according to claim 2, characterized in that: R 3-1 wherein the substituents of the substituted C1-C8 straight-chain alkyl, substituted C2-C8 branched-chain alkyl, substituted C6-C30 aryl, and substituted C5-C30 heteroaryl are halogen, hydroxy, C3-C8 cycloalkyl, C6-C20 aryl or substituted C6-C20 aryl, C5-C15 heteroaryl or substituted C5-C15 heteroaryl, wherein the substituents are selected from halogen, hydroxy, C1-C6 alkyl, and C3-C8 cycloalkyl; R 3-2 In the above, the substituent of the substituted C1~C8 straight-chain alkyl or the substituted C3~C8 branched-chain alkyl is halogen, C3~C8 cycloalkyl, C6~C20 aryl or substituted C6~C20 aryl, C5~C15 heteroaryl or substituted C5~C15 heteroaryl, wherein the substituent is selected from halogen, hydroxyl, C1~C6 alkyl and C3~C8 cycloalkyl.

6. The use according to claim 1, characterized in that: The application is the application of the 4,5,6,7-tetrahydrobenzothiophene compounds shown in formula I in agricultural and sanitary pest control.

7. The use according to claim 6, characterized in that: In the application, the agricultural pests include Ostrinia furnacalis, Plutella xylostella, Mythimna separata, Helicoverpa armigera, Aphis gossypii and Tetranychus cinnabarinus; The sanitary pests include Culex pipiens pallens.

8. An insecticide, the active ingredient of which is the 4,5,6,7-tetrahydrobenzothiophene compound represented by formula I in claim 2.

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