CN112939939B - 2- (4-chlorophenyl) pyridine compound and application thereof in pesticides - Google Patents

Abstract

The invention relates to a 2-(4-chlorophenyl)pyridine compound and its application in pesticides, and belongs to the technical field of pesticides. The structural formula of the 2-(4-chlorophenyl)pyridine compound of the present invention is formula (I): wherein, X is an oxygen atom or a sulfur atom; R is a hydrogen atom, a halogen atom, or a C1-C4 alkane group or C1~C4 alkoxy group. The compound of the present invention has a simple synthesis process, has a good poisoning effect on pests, and has a good promoting effect on the germination of vegetable seeds. It has not been reported among currently known pesticides and seed germination accelerators.

Description

2-(4-Chlorophenyl)pyridine compounds and their applications in pesticides

Technical field

The invention relates to a 2-(4-chlorophenyl)pyridine compound and its application in pesticides, and belongs to the technical field of pesticides.

Background technique

As we all know, the furan ring is an electron-rich system and can easily form intermolecular hydrogen bonds with a variety of biological enzymes. Therefore, some furan ring-containing compounds, whether natural or synthetic, have a broad spectrum of biological activities, such as inhibitors. Anti-bacterial, anti-viral, anti-tumor, insecticidal and herbicidal, etc. At the same time, these compounds usually have the characteristics of high efficiency, low toxicity, safety to non-target organisms, easy degradation in the environment, and resistance to harmful organisms. Therefore, in the research and development process of pesticides, furan ring-containing compounds show an increasingly important role.

Thiophene is an important member of heterocyclic compounds and plays a very important role. The research on thiophene derivatives also plays a very important role in medicine and pesticide chemistry. Thiophene derivatives have a variety of biological activities, such as antibacterial, antiviral, antitumor, anti-inflammatory, insecticidal and herbicidal. At the same time, compounds containing thiophene rings usually have the characteristics of high efficiency, low toxicity, safety to non-target organisms, easy degradation in the environment, and resistance to harmful organisms, and compounds with novel structures and excellent properties are constantly being released. Therefore, in the process of pesticide research and development, compounds containing thiophene rings will receive more widespread attention and become a hot spot for the creation of new pesticides.

Pyridine and its derivatives are important chemical raw materials or intermediates and have a variety of biological activities, such as antibacterial, insecticidal, rodenticide, herbicide, plant growth regulation, antidepressant, anti-infection, proton pump inhibitor, anti- Tuberculosis, vasodilation, central nervous system excitement, etc. Therefore, pyridine and its derivatives are widely used in the synthesis of pyridine drugs in pharmaceutical and pesticide products. At the same time, compounds containing pyridine rings usually have the characteristics of high efficiency, low toxicity, safety to non-target organisms, easy degradation in the environment, and resistance to harmful organisms, and compounds with novel structures and excellent properties are constantly being released. Therefore, in the process of pesticide research and development, compounds containing pyridine rings will receive more widespread attention and become a hot spot in the creation of new pesticides.

So far, there have been no reports on the use of 2-(4-chlorophenyl)pyridine compounds as pesticides and vegetable seed germination accelerators.

Contents of the invention

The first technical problem to be solved by the present invention is to provide a new 2-(4-chlorophenyl)pyridine compound.

In order to solve the first technical problem of the present invention, the structural formula of the 2-(4-chlorophenyl)pyridine compound is represented by formula (I):

Among them, X is an oxygen atom or a sulfur atom; R is a hydrogen atom, a halogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group.

"C1-C4 alkyl" refers to a straight-chain or branched alkyl group with 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl Key et al. "C1-C4 alkoxy" refers to a straight-chain or branched alkoxy group with 1 to 4 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy , sec-butoxy, tert-butoxy, etc.

In a specific embodiment, the R is a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group or an ethyl group.

In a specific embodiment, X is an oxygen atom or a sulfur atom.

In a specific embodiment, the structural formula of the 2-(4-chlorophenyl)pyridine compound is:

The second technical problem to be solved by the present invention is to provide the application of the above-mentioned compounds in the preparation of agricultural pesticides.

In a specific embodiment, the pests controlled by the agricultural pesticide are armyworms, spider mites or broad bean aphids.

The second technical problem to be solved by the present invention is to provide the application of the above-mentioned compound in preparing a seed germination accelerator.

In a specific embodiment, the seeds are vegetable seeds.

In a specific embodiment, the vegetable seeds are cucumber seeds, green pepper seeds, tomato seeds or celery seeds.

Beneficial effects:

The present invention introduces furan ring or thiophene ring into the molecular structure of pyridine, synthesizes some 2-(4-chlorophenyl)pyridine compounds, and discovers some active compounds or active lead compounds with novel structures and excellent activity, which will provide new A better foundation has been laid for the creation of pesticides.

The compound of the present invention has a simple synthesis process, has a good poisoning effect on pests, and has a good promoting effect on the germination of vegetable seeds. It has not been reported among currently known pesticides and seed germination accelerators.

Description of drawings

Figure 1 is a hydrogen nuclear magnetic spectrum of the compound of Example 1.

Figure 2 is a partially enlarged view of the hydrogen nuclear magnetic spectrum of the compound of Example 1.

Figure 3 is the NMR carbon spectrum of the compound of Example 1.

Figure 4 is a high-resolution mass spectrum of the compound of Example 1.

Figure 5 is a hydrogen nuclear magnetic spectrum of the compound of Example 2.

Figure 6 is a partially enlarged view of the hydrogen nuclear magnetic spectrum of the compound of Example 2.

Figure 7 is the NMR carbon spectrum of the compound of Example 2.

Figure 8 is a high-resolution mass spectrum of the compound of Example 2.

Figure 9 is a hydrogen nuclear magnetic spectrum of the compound of Example 3.

Figure 10 is a partially enlarged view of the hydrogen nuclear magnetic spectrum of the compound of Example 3.

Figure 11 is the NMR carbon spectrum of the compound of Example 3.

Figure 12 is a high-resolution mass spectrum of the compound of Example 3.

Figure 13 is the hydrogen nuclear magnetic spectrum of the compound of Example 4.

Figure 14 is a partially enlarged view of the hydrogen nuclear magnetic spectrum of the compound of Example 4.

Figure 15 is the NMR carbon spectrum of the compound of Example 4.

Figure 16 is a high-resolution mass spectrum of the compound of Example 4.

Figure 17 is a hydrogen nuclear magnetic spectrum of the compound of Example 5.

Figure 18 is a partially enlarged view of the hydrogen nuclear magnetic spectrum of the compound of Example 5.

Figure 19 is the NMR carbon spectrum of the compound of Example 5.

Figure 20 is a high-resolution mass spectrum of the compound of Example 5.

Figure 21 is the hydrogen nuclear magnetic spectrum of the compound of Example 6.

Figure 22 is a partially enlarged view of the hydrogen nuclear magnetic spectrum of the compound of Example 6.

Figure 23 is the NMR carbon spectrum of the compound of Example 6.

Figure 24 is a high-resolution mass spectrum of the compound of Example 6.

Detailed ways

In order to solve the first technical problem of the present invention, the structural formula of the 2-(4-chlorophenyl)pyridine compound is represented by formula (I):

Among them, X is an oxygen atom or a sulfur atom; R is a hydrogen atom, a halogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group.

"C1-C4 alkyl" refers to a straight-chain or branched alkyl group with 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl Key et al. "C1-C4 alkoxy" refers to a straight-chain or branched alkoxy group with 1 to 4 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy , sec-butoxy, tert-butoxy, etc.

The main reaction equation in the preparation process of the compound of general formula (I) is:

The meanings of R and X in the formula are the same as above.

In a specific embodiment, the R is a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group or an ethyl group.

In a specific embodiment, X is an oxygen atom or a sulfur atom.

In a specific embodiment, the structural formula of the 2-(4-chlorophenyl)pyridine compound is:

The second technical problem to be solved by the present invention is to provide the application of the above-mentioned compounds in the preparation of agricultural pesticides.

In a specific embodiment, the pests controlled by the agricultural pesticide are armyworms, spider mites or broad bean aphids.

The second technical problem to be solved by the present invention is to provide the application of the above-mentioned compound in preparing a seed germination accelerator.

In a specific embodiment, the seeds are vegetable seeds.

In a specific embodiment, the vegetable seeds are cucumber seeds, green pepper seeds, tomato seeds or celery seeds.

Specific implementations of the present invention will be further described below in conjunction with examples, but the present invention is not limited to the scope of the described embodiments.

Example 1

compound Preparation

Dissolve 10 mmol of 4-chloroacetophenone in 10 mL of absolute ethanol, and then add 10 mL of 10% NaOH ethanol solution. Stir in an ice bath, slowly drop a mixture of 10 mmol furan-2-carbaldehyde and 10 mL absolute ethanol into the above mixed solution using a constant pressure dropping funnel, react at 0 to 5°C, and use a thin-layer silica gel plate ( TLC) to check if the reaction is complete. After the reaction is completed, add 10 times the volume of distilled water to the mixed solution, adjust the pH value of the solution to neutral with 10% hydrochloric acid solution, and if any precipitate precipitates, filter and wash with distilled water. The obtained crude product was recrystallized with absolute ethanol to obtain the chalcone intermediate.

1 mmol of the homemade intermediate and 1 mmol of malononitrile were dissolved in 20 mL of methanol, and 1 mmol of potassium tert-butoxide was added thereto. After reacting at 30-40°C for 40-60 minutes, add 5 mmol of NaOH to the reaction mixture, and use TLC to check whether the reaction is complete. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a solid mixture, which is then separated by silica gel column chromatography (the eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:100) to obtain the target compound. Its physical and chemical properties are as follows:

Colorless crystal; Yield: 90%; ¹ H NMR (400MHz, DMSO-d ₆ ) δ (ppm): 8.21 (2H, d, J = 8.4Hz), 7.90-7.89 (2H, m), 7.57 (2H ,d,J＝8.4Hz),7.43(1H,d,J＝3.2Hz),7.02(1H,d,J＝0.8Hz),6.71(1H,dd,J＝3.2,1.6Hz),3.98(3H ,s); ¹³ C NMR (100MHz, DMSO-d ₆ ) δ (ppm): 164.54, 153.59, 151.10, 145.20, 141.33, 137.35, 134.49, 129.15, 128.77, 112.97, 110.85, 108.28, 103.03, 53. 65;HRMS( ESI)m/z:Calcd for C ₁₆ H ₁₂ ClNO ₂ [M+H] ⁺ :286.0629,Found:286.0621.

The hydrogen nuclear magnetic spectrum of this compound is shown in Figure 1. The overlapping or dense parts in Figure 1 are detailed in Figure 2. The NMR carbon spectrum of the compound is shown in Figure 3, and a partial enlargement of the overlapping or dense parts of the NMR carbon spectrum is also shown in Figure 3. The high-resolution mass spectrum of this compound is shown in Figure 4.

Example 2

compound Preparation

Dissolve 10 mmol of 4-chloroacetophenone in 10 mL of absolute ethanol, and then add 10 mL of 10% NaOH ethanol solution. Stir in an ice bath, slowly drop a mixture of 10 mmol 5-bromofuran-2-carbaldehyde and 10 mL absolute ethanol into the above mixed solution using a constant pressure dropping funnel, react at 0 to 5°C, and use a thin layer Check the completion of the reaction on a silica gel plate (TLC). After the reaction is completed, add 10 times the volume of distilled water to the mixed solution, adjust the pH value of the solution to neutral with 10% hydrochloric acid solution, and if any precipitate precipitates, filter and wash with distilled water. The obtained crude product was recrystallized with absolute ethanol to obtain the chalcone intermediate.

1 mmol of the homemade intermediate and 1 mmol of malononitrile were dissolved in 20 mL of methanol, and 1 mmol of potassium tert-butoxide was added thereto. After reacting at 30-40°C for 40-60 minutes, add 5 mmol of NaOH to the reaction mixture, and use TLC to check whether the reaction is complete. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a solid mixture, which is then separated by silica gel column chromatography (the eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:100) to obtain the target compound. Its physical and chemical properties are as follows:

Light yellow powder; Yield: 86%; ¹ H NMR (400MHz, DMSO-d ₆ ) δ (ppm): 8.21 (2H, d, J = 8.8Hz), 7.84 (1H, d, J = 1.2Hz), 7.56(2H,d,J＝8.8Hz),7.48(1H,d,J＝3.6Hz),6.98(1H,d,J＝1.2Hz),6.83(1H,d,J＝3.6Hz),3.98( 3H,s); ¹³ C NMR (100MHz, DMSO-d ₆ ) δ (ppm): 164.52, 153.74, 153.22, 140.22, 137.20, 134.57, 129.15, 128.80, 124.28, 115.02, 113.40, 107.79, 102.83, 5 3.73; HRMS (ESI)m/z:Calcd for C ₁₆ H ₁₁ BrClNO ₂ [M+H] ⁺ :363.9734,Found:363.9733.

The hydrogen nuclear magnetic spectrum of this compound is shown in Figure 5. The overlapping or dense parts in Figure 5 are detailed in Figure 6. The NMR carbon spectrum of the compound is shown in Figure 7, and a partial enlargement of the overlapping or dense parts of the NMR carbon spectrum is also shown in Figure 7. The high-resolution mass spectrum of this compound is shown in Figure 8.

Example 3

compound Preparation

Dissolve 10 mmol of 4-chloroacetophenone in 10 mL of absolute ethanol, and then add 10 mL of 10% NaOH ethanol solution. Stir in an ice bath, slowly drop a mixture of 10 mmol 5-methylfuran-2-carbaldehyde and 10 mL absolute ethanol into the above mixed solution using a constant pressure dropping funnel, react at 0 to 5°C, and use a thin Check whether the reaction is complete by running a silica gel plate (TLC). After the reaction is completed, add 10 times the volume of distilled water to the mixed solution, adjust the pH value of the solution to neutral with 10% hydrochloric acid solution, and if any precipitate precipitates, filter and wash with distilled water. The obtained crude product was recrystallized with absolute ethanol to obtain the chalcone intermediate.

1 mmol of the homemade intermediate and 1 mmol of malononitrile were dissolved in 20 mL of methanol, and 1 mmol of potassium tert-butoxide was added thereto. After reacting at 30-40°C for 40-60 minutes, add 5 mmol of NaOH to the reaction mixture, and use TLC to check whether the reaction is complete. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a solid mixture, which is then separated by silica gel column chromatography (the eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:100) to obtain the target compound. Its physical and chemical properties are as follows:

Colorless needle-like crystals; Yield: 87%; ¹ H NMR (400MHz, DMSO-d ₆ ) δ (ppm): 8.19 (2H, d, J = 8.8Hz), 7.80 (1H, d, J = 0.8Hz) ),7.55(2H,d,J＝8.4Hz),7.29(1H,d,J＝3.6Hz),6.93(1H,s),6.31(1H,dd,J＝3.2,0.8Hz),3.97(3H , S), 2.38 (3H, S); ¹³ C NMR (100MSO-D ₆ ) Δ (PPM): 164.53,154.35,153.43,141.44,137.42,1340,128.72, 1119.28,107. 82 ,102.36,53.60,13.97; HRMS(ESI)m/z:Calcd for C ₁₇ H ₁₄ ClNO ₂ [M+H] ⁺ :300.0786,Found:300.0775.

The hydrogen nuclear magnetic spectrum of this compound is shown in Figure 9. The overlapping or dense parts in Figure 9 are detailed in Figure 10. The NMR carbon spectrum of the compound is shown in Figure 11, and a partial enlargement of the overlapping or dense parts of the NMR carbon spectrum is also shown in Figure 11. The high-resolution mass spectrum of this compound is shown in Figure 12.

Example 4

compound Preparation

Dissolve 10 mmol of 4-chloroacetophenone in 10 mL of absolute ethanol, and then add 10 mL of 10% NaOH ethanol solution. Stir in an ice bath, slowly drop a mixture of 10 mmol thiophene-2-carbaldehyde and 10 mL absolute ethanol into the above mixed solution using a constant pressure dropping funnel, react at 0 to 5°C, and use a thin-layer silica gel plate ( TLC) to check if the reaction is complete. After the reaction is completed, add 10 times the volume of distilled water to the mixed solution, adjust the pH value of the solution to neutral with 10% hydrochloric acid solution, and if any precipitate precipitates, filter and wash with distilled water. The obtained crude product was recrystallized with absolute ethanol to obtain the chalcone intermediate.

1 mmol of the homemade intermediate and 1 mmol of malononitrile were dissolved in 20 mL of methanol, and 1 mmol of potassium tert-butoxide was added thereto. After reacting at 30-40°C for 40-60 minutes, add 5 mmol of NaOH to the reaction mixture, and use TLC to check whether the reaction is complete. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a solid mixture, which is then separated by silica gel column chromatography (the eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:100) to obtain the target compound. Its physical and chemical properties are as follows:

Colorless needle-shaped crystals; Yield: 86%; ¹ H NMR (400MHz, DMSO-d ₆ ) δ (ppm): 8.23 (2H, d, J = 8.8 Hz), 7.95 (1H, dd, J = 3.6, 1.2Hz),7.85(1H,d,J＝1.2Hz),7.75(1H,dd,J＝5.2,1.2Hz),7.57(2H,d,J＝8.4Hz),7.24(1H,dd,J＝ 4.8, 3.6Hz), 7.01 (1H, d, J = 0.8Hz), 3.99 (3H, s); ¹³ C NMR (100MHz, DMSO-d ₆ ) δ (ppm): 164.61, 153.73, 145.21, 140.71, 137.33 ,134.52,129.20,129.15,128.88,128.72,127.51,110.23,105.27,53.68; HRMS(ESI)m/z:Calcd forC ₁₆ H ₁₂ ClNOS[M+H] ⁺ :302.0401, Found:302.0399.

The hydrogen nuclear magnetic spectrum of this compound is shown in Figure 13. The overlapping or dense parts in Figure 13 are detailed in Figure 14. The NMR carbon spectrum of the compound is shown in Figure 15, and a partial enlargement of the overlapping or dense parts of the NMR carbon spectrum is also shown in Figure 15. The high-resolution mass spectrum of this compound is shown in Figure 16.

Example 5

compound Preparation

Dissolve 10 mmol of 4-chloroacetophenone in 10 mL of absolute ethanol, and then add 10 mL of 10% NaOH ethanol solution. Stir in an ice bath, slowly drop a mixture of 10 mmol 5-bromothiophene-2-carbaldehyde and 10 mL absolute ethanol into the above mixed solution using a constant pressure dropping funnel, react at 0 to 5°C, and use a thin layer Check the completion of the reaction on a silica gel plate (TLC). After the reaction is completed, add 10 times the volume of distilled water to the mixed solution, adjust the pH value of the solution to neutral with 10% hydrochloric acid solution, and if any precipitate precipitates, filter and wash with distilled water. The obtained crude product was recrystallized with absolute ethanol to obtain the chalcone intermediate.

1 mmol of the homemade intermediate and 1 mmol of malononitrile were dissolved in 20 mL of methanol, and 1 mmol of potassium tert-butoxide was added thereto. After reacting at 30-40°C for 40-60 minutes, add 5 mmol of NaOH to the reaction mixture, and use TLC to check whether the reaction is complete. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a solid mixture, which is then separated by silica gel column chromatography (the eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:100) to obtain the target compound. Its physical and chemical properties are as follows:

White needle-like crystals; Yield: 84%; ¹ H NMR (400MHz, DMSO-d ₆ ) δ (ppm): 8.22 (2H, d, J = 8.8Hz), 7.81-7.80 (2H, m), 7.56 ( 2H,d,J＝8.8Hz), 7.37(1H,d,J＝4.0Hz), 6.96(1H,d,J＝1.2Hz), 3.98(3H,s); ¹³ C NMR (100MHz, DMSO-d ₆ )δ(ppm):164.58,153.85,144.15,142.36,137.18,134.61,132.45,129.13,128.90,128.27,114.07,109.83,105.15,53.72; HRMS(ESI)m/z: Calcd for C ₁₆ H ₁₁ BrClNOS [M+H] ⁺ :379.9506,Found:379.9507.

The hydrogen nuclear magnetic spectrum of this compound is shown in Figure 17. The overlapping or dense parts in Figure 17 are detailed in Figure 18. The NMR carbon spectrum of the compound is shown in Figure 19, and a partial enlargement of the overlapping or dense parts of the NMR carbon spectrum is also shown in Figure 19. The high-resolution mass spectrum of this compound is shown in Figure 20.

Example 6

compound Preparation

Dissolve 10 mmol of 4-chloroacetophenone in 10 mL of absolute ethanol, and then add 10 mL of 10% NaOH ethanol solution. Stir in an ice bath, slowly drop a mixture of 10 mmol 5-methylthiophene-2-carbaldehyde and 10 mL absolute ethanol into the above mixed solution using a constant pressure dropping funnel, react at 0 to 5°C, and use a thin Check whether the reaction is complete by running a silica gel plate (TLC). After the reaction is completed, add 10 times the volume of distilled water to the mixed solution, adjust the pH value of the solution to neutral with 10% hydrochloric acid solution, and if any precipitate precipitates, filter and wash with distilled water. The obtained crude product was recrystallized with absolute ethanol to obtain the chalcone intermediate.

1 mmol of the homemade intermediate and 1 mmol of malononitrile were dissolved in 20 mL of methanol, and 1 mmol of potassium tert-butoxide was added thereto. After reacting at 30-40°C for 40-60 minutes, add 5 mmol of NaOH to the reaction mixture, and use TLC to check whether the reaction is complete. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a solid mixture, which is then separated by silica gel column chromatography (the eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:100) to obtain the target compound. Its physical and chemical properties are as follows:

White powder; Yield: 82%; ¹ H NMR (400MHz, DMSO-d ₆ ) δ (ppm): 8.21 (2H, d, J = 8.4Hz), 7.78 (1H, d, J = 1.2Hz), 7.75 (1H,d,J＝1.2Hz),7.56(2H,d,J＝8.8Hz),6.93(1H,dd,J＝3.6,0.8Hz),6.89(1H,d,J＝1.2Hz),3.97 (3H,s),2.38(3H,s); ¹³ C NMR (100MHz, DMSO-d ₆ )δ(ppm):164.57,153.58,145.34,142.43,138.23,137.38,134.46,129.12,128.83,127.66,127.59 ,109.78,104.67,53.62,15.66; HRMS(ESI)m/z:Calcd for C ₁₇ H ₁₄ ClNOS[M+H] ⁺ :316.0557, Found:316.0551.

The hydrogen nuclear magnetic spectrum of this compound is shown in Figure 21. The overlapping or dense parts in Figure 21 are detailed in Figure 22. The NMR carbon spectrum of the compound is shown in Figure 23, and a partial enlargement of the overlapping or dense parts of the NMR carbon spectrum is also shown in Figure 23. The high-resolution mass spectrum of this compound is shown in Figure 24.

Experimental example 1

Determination of insecticidal activity of the compounds of the present invention

(1) Test pests

The 3rd instar larvae of the armyworm, the 3rd instar nymphs of the broad bean aphid, and the adult mites of the spider mite are all sensitive strains that are raised indoors for many years.

(2) Determination method of armyworm

The sample to be tested was dissolved in dimethyl sulfoxide and diluted to a certain concentration with 0.1% Tween-80 aqueous solution. The corresponding solution without the sample to be tested was used as a negative control. Cut the corn leaves into small sections of 2×4cm, soak them in the solution to be tested for 5 seconds, then remove them, drain them and put them into a petri dish (6cm) with filter paper at the bottom. Insert 15 third-instar larvae, and then Place the animals in a laboratory with a temperature of 22 to 24°C, a relative humidity of 60%, and a light time of 14:10h to continue raising. After 24h, the death situation is recorded. Each experiment is repeated three times, and the corrected mortality rate is calculated using the following formula:

(3) Determination method of cinnabar spider mite

The sample to be tested was dissolved in dimethyl sulfoxide and diluted to a certain concentration with 0.1% Tween-80 aqueous solution. The corresponding solution without the sample to be tested was used as a negative control. Collect bean leaves with high insect population density and carefully select healthy adult mites (30 to 50 mites) to remain on the leaves. Dip the infested bean leaves into the solution to be tested for 5 seconds and then remove them. Drain them and place them on the bottom with a layer of mites. Place the culture dish (6cm) with filter paper in a laboratory with a temperature of 22 to 24°C, a relative humidity of 60%, and a light time of 14:10h to continue raising. Deaths will be recorded after 24h. Each experiment is repeated three times. And use the following formula to calculate the corrected mortality rate:

(4) Determination method of broad bean aphid

The sample to be tested was dissolved in dimethyl sulfoxide and diluted to a certain concentration with 0.1% Tween-80 aqueous solution. The corresponding solution without the sample to be tested was used as a negative control. Collect broad bean leaves with high insect population density and carefully select so that healthy third-instar nymphs (30 to 40 heads) remain on the leaves. Dip the insect-infested broad bean leaves into the solution to be tested for 5 seconds, then remove them, drain them and put them at the bottom. Place the culture dish (6cm) covered with filter paper in a laboratory with a temperature of 22 to 24°C, a relative humidity of 60%, and a light time of 14:10h to continue raising. Deaths will be recorded after 24h. Each experiment is repeated 3 times. times, and calculate the corrected mortality rate using the following formula:

(5)Experimental results

The insecticidal results of the compounds of the present invention are shown in Table 1.

Table 1: Poisonous activity of compounds of the present invention on test pests

^a : Average of three replicates.

From Table 1 above, it can be seen that the compounds of the present invention have good killing activity against these pests.

Experimental example 2

Determination of the effect of the compound of the present invention on promoting the germination of vegetable seeds

(1) Test seeds

Cucumber seeds (Zhongnong No. 8), green pepper seeds (Fengyuan No. 8), tomato seeds (Dongfeng No. 4), celery seeds (Jinnan Shiqin No. 1).

(2)Measurement method

The test compounds were dissolved in dimethyl sulfoxide respectively, and diluted with tap water containing 0.1% Tween-80 to a 20 mg/L solution for later use. Weigh 10 grams of cucumber seeds, 10 grams of green pepper seeds, 5 grams of tomato seeds and 5 grams of celery seeds respectively. Immerse them in 20 mL of the above test solution respectively, stir for 30 minutes, put them into a small sieve, rinse them with tap water 3 to 4 times, and air-dry them for later use. The corresponding solution without the test compound was used as a blank control. Select 100 seeds of uniform size and without defects that have been treated with the chemical solution and place them flat in a petri dish (9cm) covered with double-layer filter paper. The amount of water added for the first time is: 9 mL of cucumber, 7 mL of green pepper, 5 mL of tomato, and 5 mL of celery. Then put it in a constant temperature box (25±2°C) for germination. Observe once a day and replenish it quantitatively when there is water shortage. Each treatment was repeated three times. Check the germination of cucumbers after 1 day, check the germination of green peppers after 5 days, check the germination of tomatoes after 3 days, check the germination of celery after 9 days, and calculate the average germination rate of the three repetitions.

(3)Experimental results

The effects of the compounds of the present invention on promoting the germination of vegetable seeds are shown in Table 2.

Table 2 The promoting effect of the compounds of the present invention on seed germination at 20mg/L

^a : Average of three replicates.

It can be seen from Table 2 that the compounds of the present invention have a good promoting effect on the germination of the above four vegetable seeds.

Claims (6)

1.2-(4-chlorophenyl)pyridine compounds, characterized in that the structural formula of the 2-(4-chlorophenyl)pyridine compounds is represented by formula (I): Among them, X is an oxygen atom or a sulfur atom; R is a hydrogen atom, a halogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group. 2. The 2-(4-chlorophenyl)pyridine compound according to claim 1, wherein R is a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group or an ethyl group. 3. The 2-(4-chlorophenyl)pyridine compound according to claim 1 or 2, wherein X is an oxygen atom or a sulfur atom. 4. The 2-(4-chlorophenyl)pyridine compound according to claim 1 or 2, characterized in that the structural formula of the 2-(4-chlorophenyl)pyridine compound is: 5. Application of the compound according to any one of claims 1 to 4 in the preparation of agricultural pesticides; the pests controlled by the agricultural pesticides are armyworms, spider mites or broad bean aphids. 6. Application of the compound according to any one of claims 1 to 4 in preparing a seed germination accelerator, the seeds being vegetable seeds; the vegetable seeds being cucumber seeds, green pepper seeds, tomato seeds or celery seeds.