Insecticidal composition for controlling moths and preparation method thereof

Abstract

The invention relates to an insecticidal composition for controlling moths and a preparation method thereof, and belongs to the technical field of insecticides. The insecticidal composition for preventing and treating the moths is prepared from modified paeonol, ethyl carbamate and water, and the mass ratio of the modified paeonol to the ethyl carbamate is (0.05-0.1): (30-35). The paeonol analogue with phenolic hydroxyl groups, alcoholic hydroxyl groups, quaternary ammonium salts, ester groups and ether groups is synthesized by modifying the structure of paeonol, has good dispersion solubility in water, can effectively kill beet armyworms in a short time and under a small dosage after being compounded with ethyl carbamate, and has a good application prospect. And a larger development space is provided for botanical insecticides.

Description

Technical Field

[0001] The present invention relates to an insecticidal composition for controlling moth insects and a preparation method thereof, belonging to the technical field of insecticides. Background Art

[0002] The scientific name of the beet armyworm is Spodoptera exigua (Hübner, 1808), commonly known as the cabbage brown noctuid. It belongs to the order Lepidoptera and the family Noctuidae. It is a polyphagous pest that is distributed worldwide and occurs intermittently in large numbers, mainly harming vegetables. The beet armyworm harms a variety of vegetables such as scallions, cabbages, and Chinese cabbages. The larval body color of the beet armyworm varies greatly, including green, dark green, yellowish brown, blackish brown, etc. The subspiracular line on the lateral side of the abdomen is an obvious yellowish white longitudinal band, sometimes pink. The adults are active at night and hide during the day. They have strong phototaxis and weak chemotaxis. The older larvae have the habit of feigning death. The mature larvae enter the soil and spin cocoons to pupate. Seriously, the beet armyworm can eat up the mesophyll, leaving only the leaf veins, and even strip the cortex of the stem. The larvae of the beet armyworm can migrate in groups. When slightly disturbed, they will spin silk and fall to the ground, having the habit of feigning death. After the 3rd to 4th instars, the beet armyworm hides under the plants or in the soil cracks during the day and comes out to feed at night. The body wall of the beet armyworm is thick, the excretion effect is fast, and it has strong drug resistance, making it difficult to kill.

[0003] Paeonol is a phenone compound extracted and isolated from the root bark of Paeonia suffruticosa Andr. of the Ranunculaceae family and the whole plant of Cynanchum paniculatum (Bunge) Kitagawa of the Asclepiadaceae family. It has a wide range of pharmacological effects and agricultural biological activities. However, when paeonol is used to control the beet armyworm, the insecticidal effect is poor. Summary of the Invention

[0004] The purpose of the present invention is to provide an insecticidal composition for controlling moth insects and a preparation method thereof, so as to solve the problem that the insecticidal effect is poor when paeonol is currently used to control the beet armyworm.

[0005] The present invention provides an insecticidal composition for controlling moth insects, which is composed of modified paeonol, ethyl carbamate, and water. The mass ratio of the modified paeonol to ethyl carbamate is 0.05 - 0.1:30 - 35; the structure of the modified paeonol is as follows: ; Wherein, R is a C3 - C12 alkyl group.

[0006] Preferably, R is an octyl group.

[0007] Preferably, the mass fraction of the modified paeonol is 0.05 - 0.1%, and the mass fraction of ethyl carbamate is 30 - 35%.

[0008] The present invention provides a preparation method of an insecticidal composition for controlling moth insects, comprising the following steps: (1)Epoxidize 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to obtain 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone; the structure of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone is as follows: ; (2)React 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone with piperazine to obtain piperazine - grafted hydroxy - methoxyacetophenone; the structure of piperazine - grafted hydroxy - methoxyacetophenone is as follows: ; (3)React piperazine - grafted hydroxy - methoxyacetophenone with bromohydrocarbon to obtain modified paeonol; (4)Mix modified paeonol, ethyl carbamate and water evenly to obtain an insecticidal composition for controlling moth insects; the mass ratio of modified paeonol to ethyl carbamate is 0.05 - 0.1:30 - 35.

[0009] Preferably, the steps for epoxidizing 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone are as follows: Mix 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone, acetic acid, phosphotungstic acid, hydrogen peroxide and a solvent for reaction at a temperature of 60 - 70 °C for 6 - 8 h. The molar ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to hydrogen peroxide in hydrogen peroxide is 1:2.5 - 3, the molar ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to acetic acid is 1:1.5 - 2, and the mass ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to phosphotungstic acid is 2:0.5 - 1.

[0010] Preferably, the molar ratio of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone to piperazine is 2.1 - 2.2:1.

[0011] Preferably, the bromohydrocarbon is 1 - bromooctane, 1 - bromopentane or 1 - bromododecane.

[0012] Preferably, the molar ratio of piperazine - grafted hydroxy - methoxyacetophenone to bromohydrocarbon is 1:2.5 - 3, the reaction temperature is 80 - 85 °C, and the time is 5 - 7 h.

[0013] Preferably, the preparation method of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone is as follows: Heat paeonol, sodium hydroxide, potassium carbonate, benzyltriethylammonium chloride and a solvent to 80 - 85 °C, then dropwise add allyl bromide. After the addition is completed, continue the mixing reaction for 4 - 6 h to obtain 2 - allyloxy - 4 - methoxyacetophenone; then heat 2 - allyloxy - 4 - methoxyacetophenone and diethylene glycol to 185 - 190 °C and carry out the mixing reaction for 2 - 3 h to obtain 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone.

[0014] Preferably, the molar ratio of paeonol, benzyltriethylammonium chloride and allyl bromide is 1:1 to 1.2:1.5 to 1.8; the mass ratio of 2-allyloxy-4-methoxyacetophenone to diethylene glycol is 1:10 to 12.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By modifying the structure of paeonol, the present invention synthesizes a paeonol analogue with phenolic hydroxyl, alcoholic hydroxyl, quaternary ammonium salt, ester group and ether group simultaneously. It has good dispersion solubility in water. After being compounded with ethyl carbamate, it can effectively kill Spodoptera exigua in a short time and with a small dosage, providing a greater development space for plant-derived insecticides. Experimental results show that the modified paeonol synthesized in the present invention and ethyl carbamate have a synergistic effect, and the compound use of the two can greatly improve the insecticidal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1H NMR spectrum of piperazine-grafted hydroxymethoxyacetophenone prepared in Example 1 of the present invention; Figure 2 1H NMR spectrum of the modified paeonol prepared in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The following examples are intended to further illustrate the content of the present invention rather than limit the protection scope of the present invention.

[0018] Specific examples of the insecticidal composition for controlling moths and its preparation method of the present invention are as follows: Example 1

[0019] The preparation method of the insecticidal composition for controlling moths in this example includes the following steps: (1) Add paeonol, sodium hydroxide, potassium carbonate, benzyltriethylammonium chloride and N,N-dimethylformamide into a reaction kettle, stir evenly and heat to 80 °C, then dropwise add allyl bromide into the reaction kettle under stirring conditions. After the dropping is completed, continue stirring and reacting for 4 h. After the reaction is completed, add water and ethyl acetate to the reaction kettle in sequence for extraction. The organic phase obtained by extraction is subjected to vacuum distillation to obtain a concentrate, and then column chromatography separation is carried out using petroleum ether and acetone with a volume ratio of 5:1 as the eluent to obtain 2-allyloxy-4-methoxyacetophenone. Among them, the molar ratio of paeonol, benzyltriethylammonium chloride and allyl bromide is 1:1:1.5, and the mass ratio of paeonol, sodium hydroxide, potassium carbonate and N,N-dimethylformamide is 2:0.5:4.5:15.

[0020] (2) Add 2-allyloxy-4-methoxyacetophenone and diethylene glycol into the reaction kettle, then fill the reaction kettle with nitrogen, and then heat the materials in the reaction kettle to 185 °C and stir for reaction for 2 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. Carry out vacuum distillation on the obtained organic phase to obtain a concentrate, and then carry out column chromatography separation with petroleum ether and acetone with a volume ratio of 3:1 as the eluent to obtain 3-allyl-2-hydroxy-4-methoxyacetophenone. Among them, the mass ratio of 2-allyloxy-4-methoxyacetophenone to diethylene glycol is 1:10. The structure of 3-allyl-2-hydroxy-4-methoxyacetophenone is as follows: .

[0021] (3) Add 3-allyl-2-hydroxy-4-methoxyacetophenone, acetic acid, phosphotungstic acid and toluene into the reaction kettle, stir evenly and then heat to 60 °C, and then dropwise add 30% hydrogen peroxide by mass fraction into the reaction kettle under stirring conditions. After the dropping is completed, continue to stir and react for 6 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. Carry out vacuum distillation on the obtained organic phase to obtain a concentrate, and then carry out column chromatography separation with petroleum ether, acetone and ethyl acetate with a volume ratio of 4:1:0.5 as the eluent to obtain 3-epoxy-2-hydroxy-4-methoxyacetophenone. Among them, the molar ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to hydrogen peroxide in hydrogen peroxide is 1:2.5, the molar ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to acetic acid is 1:1.5, the mass ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to phosphotungstic acid is 2:0.5, and the mass ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to toluene is 1:2. The structure of 3-epoxy-2-hydroxy-4-methoxyacetophenone is as follows: .

[0022] (4) Add 3-epoxy-2-hydroxy-4-methoxyacetophenone, piperazine and toluene into the reaction kettle, then introduce nitrogen into the reaction kettle, and then heat the materials in the reaction kettle to 85 °C and stir for reaction for 5 h. After the reaction is completed, carry out vacuum distillation to obtain a concentrate, and then carry out column chromatography separation with petroleum ether, acetone and ethyl acetate with a volume ratio of 3:1:1 as the eluent to obtain piperazine-grafted hydroxymethoxyacetophenone; among them, the molar ratio of 3-epoxy-2-hydroxy-4-methoxyacetophenone to piperazine is 2.1:1, the mass ratio of 3-epoxy-2-hydroxy-4-methoxyacetophenone to toluene is 1:2, and the 1H NMR spectrum of piperazine-grafted hydroxymethoxyacetophenone is as Figure 1 shown, and the chemical structure is as follows: .

[0023] (5) Add piperazine-grafted hydroxymethoxyacetophenone, bromohydrocarbon, and acetonitrile into a reaction kettle. After stirring evenly, heat to 80 °C and stir and reflux for 5 h. After the reaction is completed, perform vacuum distillation to obtain a concentrate, and then perform column chromatography separation using petroleum ether, acetone, and ethyl acetate with a volume ratio of 4:1:1 as the eluent to obtain modified paeonol. Among them, the molar ratio of piperazine-grafted hydroxymethoxyacetophenone to bromohydrocarbon is 1:2.5, the bromohydrocarbon is 1-bromooctane, and the mass ratio of piperazine-grafted hydroxymethoxyacetophenone to acetonitrile is 1:1.5. The nuclear magnetic resonance hydrogen spectrum of the modified paeonol is as Figure 2 shown, and the chemical structure is as follows: ; Among them, R is an octyl group.

[0024] (6) Add the modified paeonol, ethyl carbamate, and water into a stirring kettle and stir evenly to obtain an insecticidal composition for controlling moth insects. Among them, the mass fraction of the modified paeonol is 0.05%, and the mass fraction of ethyl carbamate is 30%.

[0025] Example 2

[0026] The preparation method of the insecticidal composition for controlling moth insects in this example includes the following steps: (1) Add paeonol, sodium hydroxide, potassium carbonate, benzyltriethylammonium chloride, and N,N-dimethylformamide into a reaction kettle. After stirring evenly, heat to 82 °C, and then dropwise add allyl bromide into the reaction kettle under stirring conditions. After the addition is completed, continue to stir and react for 5 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. Perform vacuum distillation on the obtained organic phase to obtain a concentrate, and then perform column chromatography separation using petroleum ether and acetone with a volume ratio of 5:1 as the eluent to obtain 2-allyloxy-4-methoxyacetophenone. Among them, the molar ratio of paeonol, benzyltriethylammonium chloride, and allyl bromide is 1:1.1:1.7, and the mass ratio of paeonol, sodium hydroxide, potassium carbonate, and N,N-dimethylformamide is 2:0.5:4.5:15.

[0027] (2) Add 2-allyloxy-4-methoxyacetophenone and diethylene glycol into a reaction kettle, then fill the reaction kettle with nitrogen, and then heat the materials in the reaction kettle to 187 °C and stir and react for 2.5 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. Perform vacuum distillation on the obtained organic phase to obtain a concentrate, and then perform column chromatography separation using petroleum ether and acetone with a volume ratio of 3:1 as the eluent to obtain 3-allyl-2-hydroxy-4-methoxyacetophenone. Among them, the mass ratio of 2-allyloxy-4-methoxyacetophenone to diethylene glycol is 1:11. The structure of 3-allyl-2-hydroxy-4-methoxyacetophenone is as follows: .

[0028] (3) Add 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone, acetic acid, phosphotungstic acid and toluene into a reaction kettle. After stirring evenly, heat it to 65 °C, and then dropwise add 30% hydrogen peroxide solution by mass fraction into the reaction kettle under stirring conditions. After the dropping is completed, continue stirring and reacting for 7 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. The organic phase obtained by extraction is subjected to vacuum distillation to obtain a concentrate, and then column chromatography separation is carried out using petroleum ether, acetone and ethyl acetate with a volume ratio of 4:1:0.5 as the eluent to obtain 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone. Among them, the molar ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to hydrogen peroxide in hydrogen peroxide is 1:2.7, the molar ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to acetic acid is 1:1.7, the mass ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to phosphotungstic acid is 2:0.7, and the mass ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to toluene is 1:2.3. The structure of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone is as follows: .

[0029] (4) Add 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone, piperazine and toluene into a reaction kettle, then introduce nitrogen into the reaction kettle, and then heat the materials in the reaction kettle to 87 °C, stir and react for 6 h. After the reaction is completed, carry out vacuum distillation to obtain a concentrate, and then column chromatography separation is carried out using petroleum ether, acetone and ethyl acetate with a volume ratio of 3:1:1 as the eluent to obtain piperazine - grafted hydroxy - methoxyacetophenone; among them, the molar ratio of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone to piperazine is 2.1:1, the mass ratio of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone to toluene is 1:2.5, and the structure of piperazine - grafted hydroxy - methoxyacetophenone is as follows: .

[0030] (5) Add piperazine - grafted hydroxy - methoxyacetophenone, bromohydrocarbon and acetonitrile into a reaction kettle. After stirring evenly, heat it to 82 °C, stir and reflux for 6 h. After the reaction is completed, carry out vacuum distillation to obtain a concentrate, and then column chromatography separation is carried out using petroleum ether, acetone and ethyl acetate with a volume ratio of 4:1:1 as the eluent to obtain modified paeonol; among them, the molar ratio of piperazine - grafted hydroxy - methoxyacetophenone to bromohydrocarbon is 1:2.7, the bromohydrocarbon is 1 - bromooctane, the mass ratio of piperazine - grafted hydroxy - methoxyacetophenone to acetonitrile is 1:1.8, and the structure of modified paeonol is as follows: ; Among them, R is octyl.

[0031] (6) Add modified paeonol, ethyl carbamate and water into a stirring kettle, stir evenly to obtain an insecticidal composition for preventing and controlling moth insects; wherein, the mass fraction of modified paeonol is 0.07%, and the mass fraction of ethyl carbamate is 33%.

[0032] Example 3

[0033] The preparation method of the insecticidal composition for preventing and controlling moth insects in this example includes the following steps: (1) Add paeonol, sodium hydroxide, potassium carbonate, benzyltriethylammonium chloride and N,N-dimethylformamide into a reaction kettle, stir evenly and heat to 85 °C, then dropwise add allyl bromide into the reaction kettle under stirring conditions. After the dropping is completed, continue to stir and react for 6 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. The organic phase obtained by extraction is subjected to reduced pressure distillation to obtain a concentrate, and then column chromatography separation is carried out using petroleum ether and acetone with a volume ratio of 5:1 as the eluent to obtain 2-allyloxy-4-methoxyacetophenone. Among them, the molar ratio of paeonol, benzyltriethylammonium chloride and allyl bromide is 1:1.2:1.8, and the mass ratio of paeonol, sodium hydroxide, potassium carbonate and N,N-dimethylformamide is 2:0.5:4.5:15.

[0034] (2) Add 2-allyloxy-4-methoxyacetophenone and diethylene glycol into a reaction kettle, then fill the reaction kettle with nitrogen, and then heat the materials in the reaction kettle to 190 °C, stir and react for 3 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. The organic phase obtained by extraction is subjected to reduced pressure distillation to obtain a concentrate, and then column chromatography separation is carried out using petroleum ether and acetone with a volume ratio of 3:1 as the eluent to obtain 3-allyl-2-hydroxy-4-methoxyacetophenone. Among them, the mass ratio of 2-allyloxy-4-methoxyacetophenone and diethylene glycol is 1:12. The structure of 3-allyl-2-hydroxy-4-methoxyacetophenone is as follows: .

[0035] (3) Add 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone, acetic acid, phosphotungstic acid and toluene into the reaction kettle. After stirring evenly, heat it to 70 °C, and then dropwise add 30% hydrogen peroxide solution by mass fraction into the reaction kettle under stirring conditions. After the dropping is completed, continue to stir and react for 8 h. After the reaction is completed, add water and ethyl acetate into the reaction kettle in sequence for extraction. Carry out vacuum distillation on the obtained organic phase to obtain a concentrate, and then carry out column chromatography separation using petroleum ether, acetone and ethyl acetate with a volume ratio of 4:1:0.5 as the eluent to obtain 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone. Among them, the molar ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to hydrogen peroxide in hydrogen peroxide is 1:3, the molar ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to acetic acid is 1:2, the mass ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to phosphotungstic acid is 2:1, and the mass ratio of 3 - allyl - 2 - hydroxy - 4 - methoxyacetophenone to toluene is 1:2.5. The structure of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone is as follows: .

[0036] (4) Add 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone, piperazine and toluene into the reaction kettle, then introduce nitrogen into the reaction kettle, and then heat the materials in the reaction kettle to 90 °C and stir and react for 7 h. After the reaction is completed, carry out vacuum distillation to obtain a concentrate, and then carry out column chromatography separation using petroleum ether, acetone and ethyl acetate with a volume ratio of 3:1:1 as the eluent to obtain piperazine - grafted hydroxy - methoxyacetophenone; among them, the molar ratio of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone to piperazine is 2.2:1, the mass ratio of 3 - epoxy - 2 - hydroxy - 4 - methoxyacetophenone to toluene is 1:3, and the structure of piperazine - grafted hydroxy - methoxyacetophenone is as follows: .

[0037] (5) Add piperazine - grafted hydroxy - methoxyacetophenone, bromohydrocarbon and acetonitrile into the reaction kettle. After stirring evenly, heat it to 85 °C and stir and reflux for 7 h. After the reaction is completed, carry out vacuum distillation to obtain a concentrate, and then carry out column chromatography separation using petroleum ether, acetone and ethyl acetate with a volume ratio of 4:1:1 as the eluent to obtain modified paeonol; among them, the molar ratio of piperazine - grafted hydroxy - methoxyacetophenone to bromohydrocarbon is 1:3, the bromohydrocarbon is 1 - bromooctane, the mass ratio of piperazine - grafted hydroxy - methoxyacetophenone to acetonitrile is 1:2, and the structure of modified paeonol is as follows: ; Among them, R is octyl.

[0038] (6) Add modified paeonol, ethyl carbamate and water into a stirring kettle, stir evenly to obtain an insecticidal composition for preventing and controlling moth insects; wherein, the mass fraction of modified paeonol is 0.1%, and the mass fraction of ethyl carbamate is 35%.

[0039] Comparative Example 1 The difference between the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example and the preparation method of the insecticidal composition for preventing and controlling moth insects in Example 1 is only that in step (6) of the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example, the mass fraction of modified paeonol is 0%.

[0040] Comparative Example 2 The difference between the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example and the preparation method of the insecticidal composition for preventing and controlling moth insects in Example 1 is only that in step (6) of the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example, the mass fraction of ethyl carbamate is 0%.

[0041] Comparative Example 3 The difference between the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example and the preparation method of the insecticidal composition for preventing and controlling moth insects in Example 1 is only that in step (6) of the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example, modified paeonol is replaced by paeonol.

[0042] Comparative Example 4 The difference between the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example and the preparation method of the insecticidal composition for preventing and controlling moth insects in Example 1 is only that in step (6) of the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example, modified paeonol is replaced by 3-allyl-2-hydroxy-4-methoxyacetophenone.

[0043] Comparative Example 5 The difference between the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example and the preparation method of the insecticidal composition for preventing and controlling moth insects in Example 1 is only that in step (4) of the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example, piperazine is replaced by dimethylethylenediamine. The structure of dimethylethylenediamine is as follows: .

[0044] Comparative Example 6 The difference between the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example and the preparation method of the insecticidal composition for preventing and controlling moth insects in Example 1 is only that in step (4) of the preparation method of the insecticidal composition for preventing and controlling moth insects in this comparative example, piperazine is replaced by N1,N4-dimethyl-1,4-cyclohexanediamine. The structure of N1,N4-dimethyl-1,4-cyclohexanediamine is as follows: .

[0045] Experimental Example 1 This experimental example was used to investigate the storage stability of the insecticidal compositions for controlling moth pests prepared in each example and comparative example. The insecticidal compositions for controlling moth pests prepared in each example and comparative example were sealed and left standing at 50 °C, and whether stratification or precipitation occurred in the insecticidal compositions for controlling moth pests was observed. The experimental results showed that no stratification or precipitation occurred after standing for 60 days for all the insecticidal compositions for controlling moth pests, indicating that the insecticidal compositions for controlling moth pests of the present invention have good storage stability.

[0046] Experimental Example 2 In order to investigate the control effect of the insecticidal compositions for controlling moth pests prepared in each example and comparative example on moth pests, feeding experiments on Spodoptera exigua were carried out on the insecticidal compositions for controlling moth pests prepared in each example and comparative example. The experimental method was as follows: Fresh spinach leaves were cut into small leaf discs with an area of 2×2 cm 2 , soaked in the experimental liquid medicine for 5 s, air-dried naturally, and fed to 4th-instar Spodoptera exigua. After feeding Spodoptera exigua with the small leaf discs soaked in the sample liquid medicine for 24 h, the small leaf discs not soaked in the sample liquid medicine were replaced for feeding until Spodoptera exigua emerged. The temperature during the experiment was 25 °C, the relative humidity was 65 - 70%, the light time was 12 h, the dark time was 12 h, and light and darkness alternated. The experimental liquid medicine during the experiment was the insecticidal composition prepared in each example or comparative example. Each sample was set with three replicates, and 15 healthy and uniform-sized 4th-instar Spodoptera exigua were selected for each replicate and raised in a petri dish with a diameter of 9 cm. A layer of filter paper was laid at the bottom of the petri dish for moisturizing. During the experiment, the food intake and the number of live insects of Spodoptera exigua were recorded regularly, the mortality rate of Spodoptera exigua at different times was calculated, and the average value of the mortality rates of the three replicates corresponding to each sample was calculated as the final experimental result. The experimental results are shown in Table 1.

[0047] Table 1 Mortality rates of Spodoptera exigua at different times under different insecticidal compositions

[0048] As can be seen from Table 1, the insecticidal composition for controlling moth pests prepared by the present invention has good control effect on Spodoptera exigua and can effectively kill Spodoptera exigua in a short time and with a small dose.

[0049] From Example 1 and Comparative Examples 1-2, it can be seen that the modified paeonol and ethyl carbamate in the insecticidal composition for controlling moth pests have a synergistic effect. This may be because ethyl carbamate has good oil solubility and water solubility at the same time, which can make the modified paeonol better dissolve in water and promote the better and more uniform adhesion of the modified paeonol to plant leaves, thus exerting a better insecticidal effect.

[0050] As can be seen from Example 1 and Comparative Example 3, compared with paeonol, the modified paeonol and ethyl carbamate of the present invention have a better compounding effect, greatly improving the insecticidal effect of the insecticide.

[0051] As can be seen from Example 1 and Comparative Examples 4-6, after replacing the modified paeonol with 3-allyl-2-hydroxy-4-methoxyacetophenone, the insecticidal effect of the insecticide decreased significantly, indicating that the chemical structure of the modified paeonol and the bridging group in the middle have a significant impact on the insecticidal effect of the insecticide.

Claims

1. An insecticidal composition for controlling moth insects, characterized in that, It consists of modified paeonol, ethyl carbamate and water, and the mass ratio of the modified paeonol to ethyl carbamate is 0.05~0.1:30~35; the structure of the modified paeonol is as follows; ； Wherein, R is a C3~C12 alkyl group.

2. The insecticidal composition for preventing and controlling moth insects according to claim 1, wherein Said R is an octyl group.

3. The insecticidal composition for controlling moth insects according to claim 1 or 2, characterized in that, The mass fraction of the modified paeonol is 0.05~0.1%, and the mass fraction of ethyl carbamate is 30~35%.

4. A preparation method of an insecticidal composition for controlling moth insects, characterized in that, It includes the following steps: (1) Epoxidize 3-allyl-2-hydroxy-4-methoxyacetophenone to obtain 3-epoxy-2-hydroxy-4-methoxyacetophenone; the structure of 3-epoxy-2-hydroxy-4-methoxyacetophenone is as follows: ； (2) React 3-epoxy-2-hydroxy-4-methoxyacetophenone with piperazine to obtain piperazine-grafted hydroxy-methoxyacetophenone, and the structure of piperazine-grafted hydroxy-methoxyacetophenone is as follows: ； (3) React piperazine-grafted hydroxy-methoxyacetophenone with bromohydrocarbon to obtain modified paeonol; (4) Mix the modified paeonol, ethyl carbamate and water evenly to obtain an insecticidal composition for controlling moths; the mass ratio of the modified paeonol to ethyl carbamate is 0.05~0.1:30~35.

5. The preparation method of the insecticidal composition for preventing and controlling moth insects according to claim 4, characterized in that, The steps for epoxidizing 3-allyl-2-hydroxy-4-methoxyacetophenone are as follows: Mix and react 3-allyl-2-hydroxy-4-methoxyacetophenone, acetic acid, phosphotungstic acid, hydrogen peroxide and a solvent, the temperature is 60~70 °C, the time is 6~8 h, the molar ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to hydrogen peroxide in hydrogen peroxide is 1:2.5~3, the molar ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to acetic acid is 1:1.5~2, and the mass ratio of 3-allyl-2-hydroxy-4-methoxyacetophenone to phosphotungstic acid is 2:0.5~1.

6. The preparation method of the insecticidal composition for preventing and controlling moth insects according to claim 4, characterized in that, The molar ratio of the 3-epoxy-2-hydroxy-4-methoxyacetophenone to piperazine is 2.1~2.2:

1.

7. The preparation method of the insecticidal composition for preventing and controlling moth insects according to claim 4, characterized in that, The bromohydrocarbon is 1-bromooctane, 1-bromopentane or 1-bromododecane.

8. The preparation method of the insecticidal composition for preventing and controlling moth insects according to claim 4 or 7, characterized in that, The molar ratio of the piperazine-grafted hydroxy-methoxyacetophenone to the bromohydrocarbon is 1:2.5~3, the reaction temperature is 80~85 °C, and the time is 5~7 h.

9. The preparation method of the insecticidal composition for preventing and controlling moth insects according to claim 4, characterized in that, The preparation method of the 3-allyl-2-hydroxy-4-methoxyacetophenone is as follows: Heat paeonol, sodium hydroxide, potassium carbonate, benzyltriethylammonium chloride and a solvent to 80~85 °C, then dropwise add allyl bromide. After the addition is completed, continue to mix and react for 4~6 h to obtain 2-allyloxy-4-methoxyacetophenone; then heat 2-allyloxy-4-methoxyacetophenone and diethylene glycol to 185~190 °C and mix and react for 2~3 h to obtain 3-allyl-2-hydroxy-4-methoxyacetophenone.

10. The preparation method of the insecticidal composition for preventing and controlling moth insects according to claim 9, characterized in that, The molar ratio of the paeonol, benzyltriethylammonium chloride to allyl bromide is 1:1~1.2:1.5~1.8; the mass ratio of the 2-allyloxy-4-methoxyacetophenone to diethylene glycol is 1:10~12.

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