A method for detecting neonicotinoid pesticides and their metabolites in fruits and vegetables

Abstract

The application discloses a detection method of neonicotinoid pesticides in fruits and vegetables and metabolites thereof, and relates to the field of pesticides. The neonicotinoid pesticides in the fruits and vegetables comprise a pesticide of formula I: I, and modified silica gel prepared by using 4-(methylsulfonyl) benzylamine hydrochloride as a modifier is used for separating and detecting the neonicotinoid pesticides and the metabolites, so that good detection precision is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of pesticides, and particularly relates to a method for detecting neonicotinoid pesticides and metabolites thereof in fruits and vegetables. BACKGROUND

[0002] Agriculture is the first basic industry of the national economy, and is the premise and prerequisite for the operation and development of the national economy. Agriculture is more related to the problem of food and clothing for the world's population. According to the latest data published by the United Nations Population Division, the world's population in 2017 was about 7.6 billion, but 815 million people were in a state of hunger. By 2050, the world's population is expected to reach 9.8 billion. With the development of cities and the increase in population, the world's per capita arable land area is decreasing. In 1990, the per capita arable land area was 0.265hm 2 , in 2015, it was 0.26hm 2 , and it is predicted that by 2050, the per capita arable land area will decrease to 0.151hm 2 . In the face of the contradiction between population and arable land, only by increasing the yield per unit of arable land can the demand for food by mankind be met. However, agricultural pests represented by diseases, insects, weeds and rodents seriously restrict the production of food in the world. According to the estimate of the Food and Agriculture Organization (FAO) of the United Nations, the loss of food caused by agricultural pests accounts for 30% of the world's possible agricultural production, and the loss in developing countries is even greater. Among them, the loss caused by diseases and pests is the largest. Therefore, in order to fight agricultural pests and ensure food production, it is necessary to rely on pesticides, especially the use of chemical pesticides.

[0003] As early as the 17th century, people used natural nicotine to prevent crop diseases and insect pests, but its toxicity to mammals, birds and aquatic organisms limited its wide application. In 1970, Shell Company developed the first lead compound SD-031588 based on the structure of nicotine, and through structural optimization, obtained a heterocyclic compound Nithiazine with better activity. It has good insecticidal activity against houseflies and cotton bollworms. In 1979, Bayer Company continued to optimize and transform the structure of Nithiazine based on it as a lead compound, and obtained a second neonicotinoid lead structure NTN32692, which has 100 times the insecticidal activity of Nithiazine against black-tailed leafhoppers. However, the compound has poor light stability and rapidly decomposes in outdoor environments, limiting its commercialization. Subsequently, the research on this type of compound gradually shifted from new drug development to stability research. Based on NTN32693, by introducing a nitro imine structure, a pyridine with significantly improved light stability was discovered, and was successfully launched in 1991. The successful development of imidacloprid is hailed as a milestone in the history of insecticides, thus opening a new era of neonicotinoid insecticides.

[0004] With the extensive use of neonicotinoid insecticides, especially its high selectivity to pests, the problem of pest resistance is becoming more and more serious, which has attracted the attention of researchers all over the world. As a representative of neonicotinoid insecticides, imidacloprid has been widely used all over the world, and it has a similar mechanism of action with other neonicotinoid insecticides, so there is a great risk for other neonicotinoid insecticides. Therefore, it is of great significance to explore more novel, low-resistance and low-toxicity to bees new lead compounds and develop more environmentally friendly neonicotinoid insecticides. SUMMARY

[0005] The purpose of the present application is to provide a detection method for neonicotinoid pesticides and their metabolites in fruits and vegetables, and the neonicotinoid pesticides provided by the present application have good insecticidal activity and low toxicity to bees, and the detection method has good precision.

[0006] The technical solution adopted by the present application to achieve the above purpose is:

[0007] A neonicotinoid pesticide in fruits and vegetables, the neonicotinoid pesticide comprising a pesticide of formula I;

[0008] I.

[0009] Preferably, the neonicotinoid pesticide in fruits and vegetables further comprises cycloxaprid, nitenpyram, thiamethoxam, clothianidin, imidacloprid, chlorocholine, fluazuron and sulfoxaflor.

[0010] The present application also discloses a preparation method of the pesticide of formula I, comprising: using 2-chloro-5-chloromethylpyridine and 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole to generate a substitution reaction to generate compound a; using dimethyl malonate to generate a hydrolysis reaction in a potassium hydroxide methanol solution to generate compound b; then generating a substitution reaction with methyl chloroacetate to generate compound c; then cyclizing under the action of sodium methoxide to generate compound d; and then reacting compound d with compound a to generate the pesticide of formula I.

[0011] The present application provides a preparation method of the pesticide of formula I, using dimethyl malonate as a starting material, hydrolyzing to obtain compound b, then generating a substitution reaction with methyl chloroacetate to generate compound c, then cyclizing to generate compound d, and then reacting with compound a to generate the pesticide of formula I. The pesticide of formula I prepared by the present application has good insecticidal activity and low toxicity to bees.

[0012] Specifically, the preparation method of the pesticide of formula I comprises the following steps:

[0013] Step one, add 2-chloro-5-chloromethylpyridine in dichloromethane, stir and dissolve, then add 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole, octylphenol polyoxyethylene ether, stir and mix evenly, then slowly add triethylamine at -3℃ to 8℃, then react at 40-55℃ for 3-6h, distill under reduced pressure, concentrate and crystallize, then add deionized water, adjust the pH to 1.5-2.5, extract with ethyl acetate for 3-6 times, combine the organic phase to obtain compound a;

[0014] Step two, slowly add dimethyl malonate to potassium hydroxide methanol solution at -3℃ to 3℃, then react at 6-12℃ for 8-13h, filter, wash with water for 3-5 times, dry to obtain compound b;

[0015] Step three, add compound b to toluene, stir and mix evenly, then add tetrabutylammonium bromide, slowly add methyl chloroacetate at 45-53℃, then warm to 60-65℃ and react for 2-4h, cool to room temperature naturally, then add deionized water to separate the layers, extract the water layer with toluene, then combine the organic phase, wash with water for 3-5 times, dry to obtain compound c;

[0016] Step four, add compound c in methanol, stir and dissolve, then slowly add sodium methoxide in methanol, then heat to reflux, react for 2.5-4h, cool and crystallize, filter, wash with methanol, dry to obtain compound d;

[0017] Step five, add compound d in acetonitrile, stir and mix evenly, then add compound a, then add potassium bisulfate, heat to reflux for 10-15h, remove the solvent by rotary evaporation, add deionized water (the mass / volume ratio of compound d to deionized water is 1g:15-20mL), then extract with dichloromethane for 3-5 times, combine the organic phase, then wash with deionized water for 3-6 times, concentrate to obtain the pesticide of formula I structure.

[0018] Preferably, in step one, the mass / volume ratio of 2-chloro-5-chloromethylpyridine to dichloromethane is 1g:4-6mL; the molar ratio of 2-chloro-5-chloromethylpyridine to 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole is 1:2.5-3.5; the mass ratio of 2-chloro-5-chloromethylpyridine to octylphenol polyoxyethylene ether is 1:0.01-0.03; the molar ratio of 2-chloro-5-chloromethylpyridine to triethylamine is 1:1.3-1.8; the mass / volume ratio of 2-chloro-5-chloromethylpyridine to deionized water is 1g:4-6mL.

[0019] Preferably, in step two, the concentration of potassium hydroxide methanol solution is 0.1-0.18g / mL; the molar ratio of dimethyl malonate to potassium hydroxide is 1:1-1.3.

[0020] Preferably, in the above-mentioned step three, the mass-volume ratio of compound b to toluene is 1g:8-15mL; the molar ratio of compound b to tetrabutylammonium bromide is 1:0.01-0.013; the molar ratio of compound b to methyl chloroacetate is 1:0.8-1.5; and the mass-volume ratio of compound b to deionized water is 1g:5-8mL.

[0021] Preferably, in the above-mentioned step four, the mass-volume ratio of compound c to methanol is 1g:3-5mL; the concentration of sodium methoxide solution in methanol is 25-40wt%; and the molar ratio of compound c to sodium methoxide is 1:1-1.5.

[0022] Preferably, in the above-mentioned step five, the mass-volume ratio of compound d to acetonitrile is 1g:20-30mL; the molar ratio of compound d to compound a is 1:0.7-1; and the molar ratio of compound d to potassium bisulfate is 1:1.8-2.3.

[0023] The application further discloses a use of the pesticide with the structure of formula I prepared by the preparation method in insecticides.

[0024] The application further discloses that the nicotine pesticide and the metabolite thereof in fruits and vegetables are separated and detected by using a silica gel chromatographic column.

[0025] In order to further improve the accuracy of detection of the nicotine pesticide and the metabolite thereof in fruits and vegetables, the application further uses modified silica gel instead of silica gel.

[0026] The application further discloses a preparation method of modified silica gel, which comprises the following steps: coupling reaction of silica gel and 3-chloropropyltrimethoxysilane, and substitution reaction of the silica gel after the coupling reaction and 4-(methylsulfonyl) benzylamine hydrochloride.

[0027] The application provides a preparation method of modified silica gel, 4-(methylsulfonyl) benzylamine hydrochloride is used as a modifier, substitution reaction of silica gel after silane coupling is carried out, and the modified silica gel is prepared, and the modified silica gel is used for separation and detection of the nicotine pesticide and the metabolite thereof, and has good detection precision.

[0028] Specifically, the preparation method of the modified silica gel comprises the following steps:

[0029] The silica gel is added into a hydrochloric acid solution with a concentration of 5-7 mol / L, heated to reflux for 5-8 h, washed with deionized water until neutral, dried at 105-110 DEG C to constant weight, then added into toluene (mass-volume ratio of silica gel and toluene: 1 g: 4-7 mL), slowly added 3-chloropropyl trimethoxysilane under nitrogen atmosphere, heated to reflux for 10-15 h, filtered, washed with toluene, ethanol and ether for 3-5 times in sequence, dried to constant weight, then added into a 4-(methylsulfonyl) benzylamine hydrochloride solution, heated to reflux for 6-10 h, washed with ethanol for 3-5 times, washed with hot water at 60-80 DEG C for 3-5 times, dried, to obtain the modified silica gel.

[0030] Preferably, the mass-volume ratio of the silica gel and the hydrochloric acid solution is 1 g: 10-20 mL; the mass-volume ratio of the silica gel and 3-chloropropyl trimethoxysilane is 1 g: 0.35-0.5 mL; the mass ratio of the silica gel and 4-(methylsulfonyl) benzylamine hydrochloride is 1: 0.7-1.5.

[0031] Preferably, the concentration of the 4-(methylsulfonyl) benzylamine hydrochloride solution is 0.05-0.1 g / mL.

[0032] The application further discloses a use of the modified silica gel in detection of the neonicotinoid pesticides and metabolites thereof in fruits and vegetables.

[0033] The application has the following beneficial effects:

[0034] The application obtains a detection method of neonicotinoid pesticides and metabolites thereof in fruits and vegetables, 9 kinds of neonicotinoid pesticides in fruits and vegetables include pesticides with the structure of formula I, ethiprole, nitenpyram, thiamethoxam, clothianidin, imidacloprid, chlorocholine, fluazaindole and sulfoxaflor, and 4-(methylsulfonyl) benzylamine hydrochloride is used as a modifier, the modified silica gel is prepared, and the modified silica gel is used for separating and detecting the neonicotinoid pesticides and metabolites thereof, and has good detection precision.

[0035] Therefore, the application provides a detection method of neonicotinoid pesticides and metabolites thereof in fruits and vegetables, the neonicotinoid pesticides provided by the application have good insecticidal activity and low toxicity to bees, and the detection method has good precision. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The infrared spectrogram test results of the modified silica gel and silica gel prepared in Example 3. DETAILED DESCRIPTION

[0037] In order to make the object, technical scheme and advantages of the application clearer and more explicit, the technical scheme of the application is further described in detail below with reference to specific embodiments:

[0038] Example 1:

[0039] A method for preparing a pesticide of formula I, comprising the following steps:

[0040] Step one, add 2-chloro-5-chloromethylpyridine in dichloromethane, after stirring and dissolving, add 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole, octylphenol polyoxyethylene ether, stir and mix uniformly, then slowly add triethylamine at 0℃, then react at 40℃ for 6h, distill under reduced pressure, concentrate and crystallize, then add deionized water, adjust pH to 2, extract with ethyl acetate for 3 times, combine the organic phase, and prepare compound a;

[0041] The hydrogen spectrum of compound a is as follows:

[0042] 1 HNMR (CDCl3): 2.18 (s, 6H, N-C H 3), 3.60 (s, 2H, N-C H 2), 6.85 (1H, Thiazole- H ), 3.73 (s, 2H, Thiazole-C H 2), 2.54 (t, 2H, S-C H 2-CH2), 2.90 (t, 2H, S-CH2-C H 2), 4.17 (m, 1H, N- H ), 3.75 (d, 2H, py-C H 2), 7.32-8.69 (3H, py- H ).

[0043] Step two, slowly add dimethyl malonate to potassium hydroxide in methanol at 0℃, then react at 6℃ for 13h, filter, wash with water for 3 times, and dry to obtain compound b;

[0044] The hydrogen spectrum of compound b is as follows:

[0045] 1 HNMR (CDCl3): 3.64 (s, 3H, O-C H 3), 3.18 (s, 2H, C-C H 2).

[0046] Step three, add compound b to toluene, stir and mix uniformly, then add tetrabutylammonium bromide, slowly add methyl chloroacetate at 45℃, then warm to 60℃ and react for 4h, after natural cooling to room temperature, add deionized water to separate the layers, extract the water layer with toluene, then combine the organic phase, wash with water for 3 times, and dry to obtain compound c;

[0047] The hydrogen spectrum of compound c is as follows:

[0048] 1 HNMR (CDC13): 3.64-3.70 (6H, O-C H 3), 3.21 (s, 2H, C-C H 2-C), 5.06 (s, 2H, O-C H 2-C).

[0049] Step four, add compound c in methanol, after stirring and dissolving, slowly add sodium methoxide in methanol, then heat to reflux, react for 2.5h, cool to crystallize, filter, wash with methanol, dry, obtain compound d;

[0050] The hydrogen spectrum of compound d is as follows:

[0051] 1 HNMR (DMSO-d6): 3.72 (s, 3H, O-C H 3), 4.87 (s, 3H, C=C-C H 2).

[0052] Step five, add compound d in acetonitrile, after stirring and mixing well, add compound a, then add potassium bisulfate, heat to reflux for 10h, spin to remove solvent, add deionized water (mass / volume ratio of compound d and deionized water: 1g: 15mL), then extract with dichloromethane for 3 times, combine the organic phase, then wash with deionized water for 3-6 times, concentrate, obtain the pesticide with structure of formula I, whose structural formula is as follows:

[0053] I;

[0054] The hydrogen spectrum of the pesticide with structure of formula I is as follows:

[0055] 1 HNMR (CDC13): 2.17 (s, 6H, N-C H 3), 3.58 (s, 2H, N-C H 2), 6.83 (1H, Thiazole- H ), 3.75 (s, 2H, Thiazole-C H 2), 2.65 (t, 2H, S-C H 2-CH2), 3.52 (t, 2H, S-CH2-C H 2), 4.82 (d, 2H, py-C H 2), 7.30-8.70 (3H, py- H ), 4.87 (s, 1H, C=C H ), 4.93 (s, 2H, O-C H 2).

[0056] In step one, the mass-volume ratio of 2-chloro-5-chloromethylpyridine to dichloromethane was 1 g:4 mL; the molar ratio of 2-chloro-5-chloromethylpyridine to 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole was 1:2.5; the mass ratio of 2-chloro-5-chloromethylpyridine to octylphenol polyoxyethylene ether was 1:0.01; the molar ratio of 2-chloro-5-chloromethylpyridine to triethylamine was 1:1.3; and the mass-volume ratio of 2-chloro-5-chloromethylpyridine to deionized water was 1 g:4 mL.

[0057] In step two, the concentration of potassium hydroxide in methanol was 0.1 g / mL; and the molar ratio of dimethyl malonate to potassium hydroxide was 1:1.

[0058] In step three, the mass-volume ratio of compound b to toluene was 1 g:8 mL; the molar ratio of compound b to tetrabutylammonium bromide was 1:0.01; the molar ratio of compound b to methyl chloroacetate was 1:0.8; and the mass-volume ratio of compound b to deionized water was 1 g:5 mL.

[0059] In step four, the mass-volume ratio of compound c to methanol was 1 g:3 mL; the concentration of sodium methoxide in methanol was 25 wt%; and the molar ratio of compound c to sodium methoxide was 1:1.

[0060] In step five, the mass-volume ratio of compound d to acetonitrile was 1 g:20 mL; the molar ratio of compound d to compound a was 1:0.7; and the molar ratio of compound d to potassium bisulfate was 1:1.8.

[0061] Example 2:

[0062] A method for detecting metabolites of neonicotinoid pesticides in fruits and vegetables, comprising: adding nine neonicotinoid pesticides (the nine neonicotinoid pesticides including the pesticide of formula I prepared in Example 1, ethiprole, nitenpyram, thiamethoxam, clothianidin, imidacloprid, chlorocholine, fluazaindole and sulfoxaflor) into acetonitrile respectively to prepare nine standard solutions with a concentration of 10 mg / mL for standby. Then, NADPH is added into Tris-HCl buffer with a concentration of 0.05 mol / L, and after the addition, the concentration of NADPH is 1.5 mmol / L, then human liver microsomes are added, and after the addition, the concentration of human liver microsomes is 1 mg / mL, to prepare a mixed solution, the mixed solution is divided into nine parts, each with 200 μL, then each part is pre-incubated at 37℃ for 2 min, 1 μL of the above prepared standard solution is added respectively, and after 5 h of constant temperature incubation, 200 μL of pre-cooled acetonitrile at 0℃ is added, then centrifugation is carried out at 4℃, the centrifugation speed is 15000 r / min, and the time is 10 min, and the supernatant is separated and detected by using a silica gel chromatographic column. The control groups are respectively a group without NADPH, a group without human liver microsomes and a group without neonicotinoid pesticides, and the same method is used for incubation.

[0063] Chromatographic conditions:

[0064] Chromatographic column: C18 silica gel chromatographic column, 2.1 mm x 100 mm, 2.7 μm;

[0065] Phase A: 5 mmol / L ammonium formate-0.1% formic acid aqueous solution;

[0066] Phase B: 5 mmol / L ammonium formate-0.1% formic acid acetonitrile;

[0067] Elution gradient: 0-2 min, 5% B / 95% A (v / v); 2-7 min, 30% B / 70% A (v / v); 7-12 min, 100% B; 12-16 min, 100% B; and then back to the initial mobile phase for equilibrium for 4 min;

[0068] Flow rate: 0.4 mL / min;

[0069] Injection volume: 5 μL;

[0070] Column temperature: 25℃.

[0071] Mass spectrometry conditions:

[0072] Full MS / dd-MS is used 2Data acquisition mode, under nitrogen atmosphere, tandem mass spectrometry conditions using electrospray ionization, positive ion mode (ESI+), ion spray voltage of 4000V, sheath gas flow rate of 40L / h, auxiliary gas flow rate of 10L / h, heating temperature of 400℃, capillary temperature of 330℃, S-Lens RF voltage 60V, acquisition range m / z 50-750. Normalized collision energy: high energy 55%; medium energy 35%; low energy 10%.

[0073] Example 3:

[0074] A method for detecting metabolites of neonicotinoid pesticides in fruits and vegetables is different from that of Example 2: modified silica gel is used instead of silica gel.

[0075] A method for preparing modified silica gel includes the following steps:

[0076] Silica gel is added to a hydrochloric acid solution with a concentration of 5 mol / L, heated to reflux for 8h, washed with deionized water until neutral, dried at 105℃ to constant weight, then added to toluene (mass-volume ratio of silica gel to toluene: 1g:4mL), slowly added 3-chloropropyltrimethoxysilane under nitrogen atmosphere, heated to reflux for 10h, filtered, washed with toluene, ethanol and diethyl ether 3 times in turn, dried to constant weight, then added to a 4-(methylsulfonyl)benzylamine hydrochloride solution, heated to reflux for 6h, washed with ethanol 3 times, washed with hot water at 60℃ 5 times, dried to obtain modified silica gel.

[0077] Among them, the mass-volume ratio of silica gel to hydrochloric acid solution is: 1g:10mL; the mass-volume ratio of silica gel to 3-chloropropyltrimethoxysilane is: 1g:0.35mL; the mass ratio of silica gel to 4-(methylsulfonyl)benzylamine hydrochloride is: 1:1; the concentration of 4-(methylsulfonyl)benzylamine hydrochloride solution is 0.05g / mL.

[0078] Test example:

[0079] 1. Infrared spectroscopy test

[0080] A TENSOR 27 series infrared spectrometer from Germany Bruker was used for analysis and testing.

[0081] The modified silica gel prepared in Example 3 and silica gel were tested as described above, and the results are shown in Figure 1 As can be seen from Figure 1 , compared with the infrared spectrum of silica gel, the infrared spectrum of modified silica gel has an infrared characteristic absorption peak of C-Si bond at 1167cm -1 , and an infrared characteristic absorption peak of benzene ring at 1400-1600cm -1 ; it is shown that 3-chloropropyltrimethoxysilane and 4-(methylsulfonyl)benzylamine hydrochloride both participate in the generation reaction of modified silica gel.

[0082] 2. Insecticidal activity test

[0083] The neonicotinoid pesticide was added to DMF to prepare a preparation with a concentration of 2.5 wt%, then diluted to 100 mg / L with Tween water with a concentration of 1 wt% to prepare a pesticide solution, with Tween water containing an equal amount of DMF solvent as a blank control group, and then 100 alfalfa aphid adults were added to the clover leaf and immersed in the above pesticide solution, placed for 5 s and then taken out to dry, then the soaked leaves were placed in a culture dish under the condition of 23±1℃ and incubated for 36 h. The results were checked by gently touching the insect body, and those with no reaction or delayed reaction and unable to crawl normally were determined as dead. The number of dead insects and live insects was counted, and the mortality rate was calculated.

[0084] Corrected mortality rate = [(sample mortality rate-blank control mortality rate) / (1-blank control mortality rate)]x100%.

[0085] Table 1 Insecticidal activity test results

[0086]

[0087] The above test was performed on the pesticide of formula I structure prepared in Example 1, cyhalothrin, nitenpyram, thiamethoxam, clothianidin, imidacloprid, chlorocholine, fluopyram and sulfoxaflor, respectively, and the results are shown in Table 1. As can be seen from Table 1, the pesticide of formula I structure disclosed in the present application has a high corrected mortality rate, indicating that the pesticide of formula I structure prepared in the present application has high insecticidal activity.

[0088] 3. Precision test

[0089] The precision of the neonicotinoid pesticide test was evaluated according to the relative standard deviation.

[0090] Table 2 Precision test results

[0091]

[0092] The above test was performed on Example 2-Example 3, and the results are shown in Table 2. As can be seen from Table 2, the relative standard deviation of Example 3 compared with Example 2 decreased significantly, indicating that the modified silica gel prepared by using 4-(methylsulfonyl) benzylamine hydrochloride has good precision for separation and detection.

[0093] 3. Test of toxicity to bees

[0094] In 500 mL of water, sucrose is added to prepare a 1 mol / L sucrose solution, and then neonicotinoid pesticide is added to obtain a neonicotinoid pesticide agent, and the concentration of the neonicotinoid pesticide in the agent is 2 mg / L; the strong group of bees is divided into 3 groups, each group having 100 bees, and each bee is fed with 10 μL of the neonicotinoid pesticide agent, and the control group is fed with an equal amount of sucrose solution, and then the bees are placed in an environment with a temperature of 27.5°C and a humidity of 65%, and after 24 hours, the mortality rate of the bees is recorded.

[0095] Table 3: Test results of the toxicity of neonicotinoid pesticides on bees

[0096]

[0097] The above test is performed on the pesticide with the structure of formula I prepared in Example 1 and flupyradifurone, and the results are shown in Table 3. As shown in Table 3, the pesticide with the structure of formula I causes a significantly reduced mortality rate of bees compared with flupyradifurone, indicating that the pesticide with the structure of formula I has lower toxicity on bees compared with flupyradifurone.

[0098] The conventional techniques in the above examples are prior art known to those skilled in the art, and thus are not described in detail herein.

[0099] The above description is merely a specific implementation of the present application, and the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, and all such changes or replacements should be encompassed in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A nicotine-based pesticide in fruits and vegetables, characterized by: The nicotine pesticide comprises a pesticide with a structure of Formula I; Ⅰ。 2. The nicotine pesticide in fruits and vegetables according to claim 1, characterized in that: The nicotine pesticide in the fruits and vegetables further comprises at least one of nitenpyram, nitenpyram, thiamethoxam, clothianidin, imidacloprid, chlorocholine, fluopyram and sulfoxaflor.

3. A process for the preparation of a pesticide of the structure of claim 1 comprising: 2-chloro-5-chloromethylpyridine and 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole are subjected to a substitution reaction to generate compound a; dimethyl malonate is subjected to a hydrolysis reaction in a potassium hydroxide methanol solution to generate compound b; then a substitution reaction with methyl chloroacetate is performed to generate compound c; then cyclization is performed under the action of sodium methoxide to generate compound d; and then compound d and compound a are reacted to generate the pesticide with the structure of Formula I.

4. The process for the preparation of a pesticide of the structure of claim 3, characterized by: The molar ratio of 2-chloro-5-chloromethylpyridine to 2-(dimethylaminomethyl)-4-(2-aminoethylthiomethyl)thiazole is 1:2.5-3.

5.

5. The process for the preparation of a pesticide of the structure of claim 3, characterized by: The molar ratio of compound b to methyl chloroacetate is 1:0.8-1.

5.

6. The process for the preparation of a pesticide of the structure of claim 3, characterized by: The molar ratio of compound c to sodium methoxide is 1:1-1.

5.

7. The process for the preparation of a pesticide of the structure of claim 3, characterized by: The molar ratio of compound d to compound a is 1:0.7-1.

8. Use of the pesticide with the structure of Formula I prepared by the preparation method of any one of claims 3-7 in an insecticide.

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