Bobicylon herbicide ionic liquid as well as preparation method and application thereof

Abstract

The invention discloses benzobicylon herbicide ionic liquid as well as a preparation method and application thereof, and belongs to the technical field of agricultural herbicide preparations. The benzobicylon herbicide ionic liquid has a molecular structure as shown in formula (I), in the formula (I), R1, R2 and R3 are respectively and independently selected from-CH3 and-H, and R4 is selected from-C8H17,-C10H21 and-C12H25. The benzobicylon herbicide ionic liquid disclosed by the invention is obtained by reacting tertiary amine or quaternary ammonium salt with a triketone structure in an active form of benzobicylon. The benzobicylon herbicide ionic liquid has good water solubility and does not need an auxiliary agent; the plant leaf surface wetting ability is strong, the bioavailability is high, and the weed killing ability is strong; the herbicide has the characteristics of low aquatic toxicity, good crop safety and the like, and can realize application reduction and synergism of benzobicylon. Formula (I).

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of agricultural herbicides, and particularly relates to a class of benzobicyclon herbicide ionic liquids, a preparation method and application thereof. BACKGROUND

[0002] With the development of global agricultural intensification, weed management has become a key challenge to food security. As a representative of triketone para-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors, benzobicyclon has shown significant advantages in rice field weed management due to its unique molecular structure and mechanism of action (J Agric Food Chem, 2016, 64, 4838). Benzobicyclon is a pro-herbicide, which is hydrolyzed into an active form in the environment, also known as benzobicyclon hydrolysate (BH), and its chemical name is 3-[2-chloro-4-(methylsulfonyl) benzoyl] bicyclo[3.2.1] octane-2,4-dione. The mechanism of action of benzobicyclon herbicide is to inhibit HPPD and hinder carotenoid synthesis, resulting in the death of weeds (J. Pestic. Sci. 2009, 34, 113). Benzobicyclon has the characteristics of broad-spectrum herbicidal activity and good selectivity, but has the disadvantages of poor water solubility and single dosage form. The existing benzobicyclon dosage forms are mainly traditional forms such as emulsifiable concentrate and suspension concentrate, which have the limitations of high toxicity of adjuvants, poor dispersion stability, etc. The core problem of benzobicyclon formulation innovation is to improve its bioavailability through formulation technology innovation.

[0003] In recent years, ionic liquids have been introduced into the field of herbicides due to their unique physicochemical properties, such as low volatility, high stability, and adjustable physicochemical properties, providing a new way to improve the delivery efficiency and bioavailability of active ingredients. Ionic compounds composed of organic cations and herbicide anions form herbicide ionic liquids (HILs) with melting points between room temperature and 100 ℃, combining the characteristics of liquids and solids. They are considered a promising new herbicide dosage form because they are non-flammable and non-explosive, have high thermal stability, and do not require the use of adjuvants (J. Agric. Food Chem. 2020, 68, 4588). CN110003270B discloses a glyphosate dicationic ionic liquid compound, its preparation method and application. The preferred cations include quaternary ammonium cations, piperidine cations, pyrrole cations, pyridine cations, and imidazole cations. CN101621925A discloses ionic liquids derived from carboxylic acid herbicides and some trialkylamines or heteroaryl amines. The preferred cations include N-alkyl imidazole, N-alkyl-N,N-dimethyl amine, and N-alkyl pyrrolidine. However, the total number of carbon atoms in some of the cation compounds in the above patents is as high as 20 or more, and the toxicity of the cations is not considered. The organic cation part of many ionic liquids has phytotoxicity and aquatic toxicity, which may pose greater environmental risks than the herbicide itself (Sci. Total Environ 2024, 922, 171062). SUMMARY

[0004] The present application uses model plants Arabidopsis thaliana and model aquatic organisms zebrafish for toxicity screening to obtain low-toxicity tertiary amine salts or quaternary ammonium salts. These quaternary ammonium salt cations and the active form of bicyclo sulfonyl ketone form herbicide ionic liquids, which reduce the ecological risk to non-target organisms, improve crop safety, and enhance the bioavailability and herbicidal efficiency of bicyclo sulfonyl ketone.

[0005] The purpose of the present application is to overcome the problems of low solubility, single dosage form, high cost, and low bioavailability of existing bicyclo sulfonyl ketone formulations and their applications, and to provide a class of bicyclo sulfonyl ketone herbicide ionic liquid compounds, their preparation method, and their application as a new herbicide dosage form.

[0006] To achieve the above purpose, the present application provides a new type of bicyclo sulfonyl ketone herbicide ionic liquid compound, which has the chemical structure shown in formula (I):

[0007] Formula (I) In formula (I), the anion part is the anion form of BH. The cation part is a protonated tertiary amine salt and a quaternary ammonium salt, R1, R2, and R3 are each independently selected from -CH3 and -H, and R4 is selected from -C8H17 , -C 10 H 21 , -C 12 H 25 As preferred, the cationic moiety is N , N - dimethyloctylamine, N , N - dimethyldecylamine, N , N - dimethyldodecylamine, and N,N,N - trimethyloctylammonium salt, N,N,N - trimethyldecylammonium salt, N,N,N - trimethyldodecylammonium salt, and the corresponding bicyclo sulfonylurea herbicide ionic liquid compounds are numbered as BH-1~BH-6, respectively.

[0008] The bicyclo sulfonylurea herbicide ionic liquid compounds of the present application, whose cationic moiety is tertiary amine salt or quaternary ammonium salt, have low toxicity to model plants and model aquatic organisms after toxicity test screening of model plants Arabidopsis thaliana and model aquatic organisms zebrafish.

[0009] The present application also provides a preparation method of the above-mentioned bicyclo sulfonylurea herbicide ionic liquid compounds. According to the difference of the cationic moiety, two synthetic routes are adopted. When the cationic moiety is a protonated tertiary amine salt, i.e. two of R1, R2, and R3 are -CH3 and one is -H, the preparation method adopts synthetic route 1, which uses the basicity of tertiary amine and the acidity of the triketone structural unit of BH to react to obtain the bicyclo sulfonylurea herbicide ionic liquid compound. When the cationic moiety is a quaternary ammonium salt, i.e. R1, R2, and R3 are all -CH3, the preparation method adopts synthetic route 2, which reacts N , N , N - trimethylalkylammonium halide salt with inorganic base to obtain the corresponding ammonium hydroxide salt, and further reacts with BH to obtain the bicyclo sulfonylurea herbicide ionic liquid compound; the said preparation method includes N , N , N - trimethylalkylammonium bromide salt, N , N , N - trimethylalkylammonium chloride salt, N , N , N - trimethylalkylammonium iodide salt, etc., wherein the alkyl group is selected from -C8H 17 , -C 10 H 21 , -C 12 H 25 , etc.

[0010] Further, the synthesis route 1 comprises the following steps: the reaction of the tertiary amine and BH in a solvent to obtain the bicyclo sulfone herbicide ionic liquid compound. The molar ratio of the tertiary amine and BH is preferably 1:1; the solvent comprises anhydrous methanol, acetonitrile, tetrahydrofuran, acetone and the like, and is preferably anhydrous methanol; the reaction temperature is preferably room temperature, the reaction is preferably carried out under stirring, the reaction time is 2-12 h, and is preferably 4 h.

[0011] Further, the synthesis route 2 comprises the following steps: (1) N , N , N The reaction of the trimethyl alkyl ammonium bromide salt and the inorganic base in a solvent to obtain the ammonium hydroxide salt. The inorganic base comprises NaOH, KOH and the like, and is preferably KOH; N , N , N The molar ratio of the trimethyl alkyl ammonium bromide salt and the inorganic base is preferably 1:1; the solvent comprises anhydrous methanol, acetonitrile, tetrahydrofuran, acetone and the like, and is preferably anhydrous methanol; the reaction temperature is preferably room temperature, the reaction is preferably carried out under stirring, the reaction time is 0.5-2 h, and is preferably 1 h.

[0012] The reaction of the ammonium hydroxide salt and BH in a solvent to obtain the bicyclo sulfone herbicide ionic liquid compound. The molar ratio of the ammonium hydroxide salt and BH is preferably 1:1; the solvent comprises anhydrous methanol, acetonitrile, tetrahydrofuran, acetone and the like, and is preferably anhydrous methanol; the reaction temperature is preferably room temperature, the reaction is preferably carried out under stirring, the reaction time is 2-12 h, and is preferably 4 h.

[0013] In the steps of the synthesis route 1 or the synthesis route 2, a step of separation and purification is further included: the reaction liquid containing the bicyclo sulfone herbicide ionic liquid compound is subjected to rotary distillation to remove the solvent, then is dissolved in acetone, filtered, and subjected to rotary distillation to remove the acetone.

[0014] The application further provides the application of the above bicyclo sulfone herbicide ionic liquid compound in the preparation of herbicides or in the control of weeds. The bicyclo sulfone herbicide ionic liquid compound is used alone as a herbicide, or is mixed with other plant protection carriers or diluents allowed in the art to be formulated into a mixture, a granule or an emulsion in water for use, or is used in combination or simultaneously with other pesticide fungicides, insecticides, herbicides or plant growth regulators.

[0015] This invention characterizes the ionic liquid compound of bicyclosulfuron herbicide, testing its properties, water solubility, dynamic light scattering, surface activity, aquatic toxicity, herbicidal activity, and crop safety. The results show that the bicyclosulfuron herbicide ionic liquid has the characteristics of good water solubility, simple formulation composition, strong wetting ability, low aquatic toxicity, high bioavailability, and good crop safety. Its herbicidal effect is superior to BH, and it can achieve the goal of reducing the application of bicyclosulfuron while increasing its efficacy. Attached Figure Description

[0016] Figure 1 The structural formula of the bicyclic sulfonamide herbicide ionic liquid of the present invention.

[0017] Figure 2 The growth inhibition of cationic compounds on Arabidopsis thaliana.

[0018] Figure 3 Acute toxicity of cationic compounds to zebrafish. (a): [C10MIm]Br ([CnMIm]Br and [CnTA]Br, n = 4, 6, 8, 10, with the same acute toxicity); (b): [C12MIm]Br; (c): [C12TA]Br.

[0019] Figure 4 (a) Scanning electron microscope image of BH-5; (b) Scanning electron microscope image of BH.

[0020] Figure 5 Surface tension of BH-1 to BH-6 aqueous solutions and leaf spreadability of plants. (a) Surface tension of aqueous solution; (b) Contact angle of aqueous solution on rice and cotton leaves.

[0021] Figure 6 Acute toxicity of BH-1 to BH-6. (a) Acute toxicity of BH-1 (BH-2 to BH-5 have the same acute toxicity as BH-1); (b) Acute toxicity of BH-6.

[0022] Figure 7 Growth inhibition of BH-1 to BH-6 on Arabidopsis thaliana.

[0023] Figure 8 Growth inhibition of BH-1 to BH-6 on rice. (a-f) BH-1 to BH-6; (g) BH; (h) CK. The concentration applied on the left side of each graph is 1000 mg / L, and the concentration applied on the right side is 2000 mg / L. Detailed Implementation

[0024] This invention utilizes toxicity screening of the model plant Arabidopsis thaliana and the model aquatic organism zebrafish to obtain low-toxicity tertiary amine salts or quaternary ammonium salts. These low-toxicity quaternary ammonium salt cations are then combined with the active form of bicyclosulfuron (BH) to construct a herbicide ionic liquid. The bicyclosulfuron herbicide ionic liquid of this invention improves the water solubility of bicyclosulfuron, requires no adjuvants, has a simple formulation composition, and helps reduce the formulation cost of bicyclosulfuron. The surface activity of the ionic liquid itself allows it to spontaneously disperse in water, forming a nanoemulsion, which enhances the wettability of the formulation on plant surfaces. This facilitates the penetration of BH in molecular form through the waxy layer of plant leaves, into the plant, and its binding to the target protein p-hydroxyphenylpyruvate dioxygenase (HPPD), thereby improving its weeding efficiency. The adjuvant-free and highly bioavailable characteristics of the bicyclosulfuron herbicide ionic liquid formulation effectively reduce environmental and aquatic toxicity. The ionic liquid formulation of bicyclosulfuron herbicide of the present invention is a supplement and improvement to the existing bicyclosulfuron suspension formulation, achieving reduced application and increased efficiency of bicyclosulfuron.

[0025] The following embodiments are used to further illustrate the present invention, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0026] Example 1: Toxicity screening of cationic compounds in Arabidopsis thaliana, a model plant The toxicity of 11 cationic compounds was screened against that of the model plant Arabidopsis thaliana. Among them, the alkyl methyl imidazole bromide ([CnMIm]Br) cationic compounds were obtained by nucleophilic substitution reaction of methyl imidazole with bromoalkane, including [C4MIm]Br, [C6MIm]Br, [C8MIm]Br, [C10MIm]Br, [C12MIm]Br, and [C16MIm]Br; the alkyl trimethylammonium bromide ([CnTA]Br) cationic compounds were all purchased, including [C4TA]Br, [C6TA]Br, [C8TA]Br, [C10TA]Br, and [C12TA]Br.

[0027] The inhibitory activity of cationic compounds on Arabidopsis thaliana growth was evaluated using a 24-well plate method. First, Arabidopsis seeds were soaked in 75% ethanol for 30 seconds, washed three times with sterile water, and aspirated onto filter paper to air dry. Then, 0.9 mL of growth medium (0.62 g 1 / 2 MS medium, 3 mg FeSO4·7H2O, 2.5 g sucrose, 0.125 g 2-morpholine ethanesulfonic acid, and 2.3 g agar per 250 mL of growth medium, pH = 5.8) and 0.1 mL of a 1000 mg / L cationic compound solution were added to each well. After the growth medium solidified, seeds were placed on the surface of the medium, 6 seeds per well. The multi-well plates were sealed with paraffin film and stored at 4 °C for 2 days, after which they were transferred to an artificial climate chamber (RXZ-380 C, Ningbo, China) under the following conditions: 25 °C, 75% humidity, 16 h light per day, and 8 h dark per day. Arabidopsis seeds were cultured for 10 days in a medium containing 100 mg / L cationic compounds. The growth of the Arabidopsis was observed, and the multi-well plate was photographed using a digital camera. Figure 2 As shown.

[0028] from Figure 2 It can be seen that the toxicity of both types of cationic compounds gradually increases with the increase of carbon chain length. For imidazole cationic compounds, Arabidopsis thaliana only grows very small green shoots when the number of carbon atoms reaches 8 or more. For aliphatic ammonium cationic compounds, a significant inhibitory effect is only observed when the number of carbon atoms reaches 12. Under the same carbon chain length, aliphatic ammonium cationic compounds are less toxic than imidazole cationic compounds.

[0029] Example 2: Toxicity screening of cationic compounds in zebrafish, a model aquatic organism The above-mentioned cationic compounds were subjected to acute toxicity tests in zebrafish at three concentrations of 1, 5, and 10 mg / L, according to Part 12 of the Guidelines for Environmental Safety Evaluation of Chemical Pesticides: Acute Toxicity Tests for Fish (GB / T 31270.12-2014). The LC-15 concentrations for fish were used as the test parameters. 50 The (96 h) value is used to classify the toxicity of pesticides to fish into low toxicity (LC). 50 >10 mg / L), poisoning (1.0 mg / L <LC) 50 ≤10 mg / L), highly toxic (0.1 mg / L < LC) 50 ≤1.0 mg / L), highly toxic (LC50) 50 Four levels (≤0.1 mg / L).

[0030] See results Figure 3 Short-chain cationic compounds did not cause mortality in zebrafish, and the LC-12 activity of these compounds in zebrafish was [not specified]. 50(96 h) > 10 mg / L. According to the pesticide toxicity classification for fish, both belong to the low toxicity category; while [C12MIm]Br and dodecyltrimethylammonium bromide have a toxicity of 1.0 mg / L < LC50 for zebrafish. 50 ≤10 mg / L is classified as moderately toxic. Acute toxicity tests indicate that when the alkyl chain length has ≤10 carbon atoms, the toxicity to the zebrafish model organism is low; when the number of carbon atoms is greater than 10, the toxicity to the zebrafish model organism increases, making it unsuitable for high-dose use.

[0031] Based on the toxicity screening results of model plants and model aquatic organisms in Examples 1 and 2, cationic compounds with alkyl chain lengths ≤10 are suitable as cations to form ionic liquids with herbicides.

[0032] Example 3 Synthesis of the bicyclosulfonamide herbicide ionic liquid BH-1 Add BH (2.00 g, 12.71 mmol) sequentially to a dry 100 mL round-bottom flask. N , N Dimethyl octylamine (4.54 g, 12.71 mmol) was dissolved in 20 mL of anhydrous methanol under electromagnetic stirring at room temperature. The solution was dark brown, and the reaction was continued at room temperature for 4 h. The mixture was filtered, rotary evaporated, and the residue was washed with acetone. The filtrate was collected, and the product was collected by rotary evaporation. The product was dried under vacuum to give BH-1, a brown solid, 5.69 g, yield: 87%.

[0033] BH-1:mp 122.9 ~ 124.2 ℃. 1 H NMR (400 MHz, Chloroform- d ) δ 7.88 (d, J =1.7 Hz, 1H), 7.78 (dd, J = 7.9, 1.7 Hz, 1H), 7.26 (d, J = 3.6 Hz, 1H), 3.05 (s,3H), 3.01 – 2.91 (m, 2H), 2.80 (s, 6H), 2.79 – 2.73 (m, 2H), 2.13 (d, J = 11.5Hz, 1H), 2.06 – 1.96 (m, 2H), 1.82 (d, J = 7.9 Hz, 2H), 1.73 – 1.60 (m, 2H), 1.56 (dt, J = 11.6, 4.3 Hz, 1H), 1.28 (dt, J= 16.7, 4.4 Hz, 10H), 0.87 (t, J = 6.7Hz, 3H). 13 C NMR (101 MHz, Chloroform- d ) δ 201.71, 189.97, 151.01, 138.96,130.22, 128.04, 127.03, 125.73, 110.40, 58.54, 50.47, 44.73, 43.67, 34.67,31.65, 29.09, 29.01, 28.00, 26.61, 24.45, 22.56, 14.08.ESI-MS(M + ) calcd for[C 10 H 24 N + ]158.1903, found 158.1905.ESI-MS(M - ) calcd for [C 16 H 14 ClO5S - ]353.0256,found 353.0256. Example 4 Synthesis of the bicyclosulfuron herbicide ionic liquid BH-2 According to the synthesis method of Example 3, N , N - Dimethyloctylamine replaced with N , N -Dimethyldecylamine yields BH-2, a brown solid, 5.23 g, yield: 89%.

[0034] BH-2:mp 97.7 ~ 99.4 ℃. 1 H NMR (400 MHz, Chloroform- d ) δ 7.88 (d, J =1.8 Hz, 1H), 7.78 (dd, J = 8.0, 1.8 Hz, 1H), 7.28 (s, 1H), 3.07 (s, 3H), 3.02 –2.92 (m, 2H), 2.82 (s, 6H), 2.77 (q, J = 3.8 Hz, 2H), 2.14 (d, J= 11.5 Hz, 1H),2.10 – 1.97 (m, 2H), 1.89 – 1.77 (m, 2H), 1.69 (dq, J = 15.8, 8.0, 7.4 Hz, 2H),1.57 (dt, J = 11.5, 4.3 Hz, 1H), 1.39 – 1.21 (m, 14H), 0.89 (t, J = 6.8 Hz, 3H). 13 C NMR (101 MHz, Chloroform- d ) δ 201.75, 139.08, 130.24, 128.07, 127.08,125.76, 110.48, 58.64, 50.45, 44.73, 43.77, 43.75, 34.69, 31.84, 29.45,29.38, 29.24, 29.18, 27.99, 26.68, 24.60, 22.66, 14.12.ESI-MS(M + ) calcd for[C 12 H 28 N + ]186.2216, found 186.2215.ESI-MS(M - ) calcd for [C 16 H 14 ClO5S - ]353.0256, found 353.0255. Example 5 Synthesis of the bicyclosulfonamide herbicide ionic liquid BH-3 According to the synthesis method of Example 3, N , N - Dimethyloctylamine replaced with N , N -Dimethyldodecylamine yields BH-3, a brown solid, 4.75 g, yield: 88%.

[0035] BH-3:mp 122.3 ~ 123.7 ℃. 1 H NMR (400 MHz, Chloroform- d ) δ 7.87 (d, J =1.7 Hz, 1H), 7.77 (dd, J = 8.0, 1.7 Hz, 1H), 7.26 (d, J= 2.4 Hz, 1H), 3.05 (s,3H), 3.01 – 2.92 (m, 2H), 2.81 (s, 6H), 2.76 (q, J = 3.8 Hz, 2H), 2.12 (d, J =11.5 Hz, 1H), 2.07 – 1.94 (m, 2H), 1.82 (t, J = 7.0 Hz, 2H), 1.66 (dq, J = 11.6,7.3, 6.0 Hz, 2H), 1.56 (dt, J = 11.5, 4.3 Hz, 1H), 1.25 (s, 18H), 0.87 (t, J =6.7 Hz, 3H). 13 C NMR(101 MHz, Chloroform-d) δ 201.74, 190.14, 150.80, 139.06,130.23, 128.08, 128.06, 127.04, 125.76, 110.42, 77.44, 77.12, 76.80, 58.57,50.44, 50.42, 44.73, 43.69, 43.66, 34.69, 31.89, 29.58, 29.48, 29.37, 29.32,29.17, 27.99, 26.64, 26.63, 24.49, 24.45, 22.68, 14.14. ESI-MS(M + ) calcd for[C 14 H 32 N + ]214.2529, found 214.2528.ESI-MS(M - ) calcd for [C 16 H 14 ClO5S - ]353.0256,found 353.0256. Example 6 Synthesis of the bicyclosulfonamide herbicide ionic liquid BH-4 Add to a dry 100 mL round-bottom flask N , N , N- Trimethyloctylammonium bromide (4.60 g, 18.24 mmol) and 20 mL anhydrous methanol; separately, KOH (1.02 g, 18.24 mmol) was added to a 10 mL test tube, dissolved in 5 mL of anhydrous methanol, and the KOH solution was added to a round-bottom flask. The mixture was stirred electromagnetically at room temperature, and a white precipitate of potassium bromide appeared after 0.5 h. The mixture was filtered, and the filtrate was transferred to a 100 mL round-bottom flask. The solvent was rotary evaporated, and the filtrate weighed 2.92 g. BH (5.47 g, 15.42 mmol) and 20 mL anhydrous methanol were added at a 1:1 molar ratio. The mixture was reacted at room temperature for 4 h, filtered, and the residue was washed with acetone. The filtrate was collected, and the product was collected by rotary evaporation. The product was dried under vacuum to obtain BH-4, a brown solid, 7.25 g, yield: 89%.

[0036] BH-4:mp 96.9~98.5 ℃. 1 H NMR (400 MHz, Chloroform- d ) δ 7.82 – 7.77(m, 1H), 7.72 (ddd, J = 8.0, 5.7, 2.3 Hz, 1H), 7.27 (d, J = 6.1 Hz, 1H), 3.34(dq, J = 8.1, 4.1, 3.5 Hz, 2H), 3.29 – 3.16 (m, 9H), 3.04 (d, J = 3.0 Hz, 3H), 2.70 (p, J = 3.2 Hz, 2H), 2.10 (dd, J = 11.9, 5.5 Hz, 1H), 1.96 (dt, J = 10.2, 4.5Hz, 2H), 1.79 (q, J = 6.3 Hz, 2H), 1.69 (d, J = 8.2 Hz, 2H), 1.50 (ddt, J = 11.4,8.4, 3.4 Hz, 1H), 1.39 – 1.16 (m, 10H), 0.87 (td, J = 6.8, 3.0 Hz, 3H). 13 C NMR (101 MHz, Chloroform- d) δ 201.18, 130.12, 127.84, 127.44, 125.75, 110.30,67.11, 53.41, 50.50, 44.64, 34.74, 31.61, 29.10, 28.99, 28.01, 26.16, 23.14,22.56, 14.07.ESI-MS(M + ) calcd for [C 11 H 26 N + ]172.2060, found 172.2060.ESI-MS(M - )calcd for [C 16 H 14 ClO5S - ]353.0256, found 353.0257. Example 7 Synthesis of the bicyclosulfonamide herbicide ionic liquid BH-5 According to the synthesis method of Example 6, N , N , N - Trimethyloctylammonium bromide replaced N , N , N -Trimethyldecylammonium bromide yields BH-5, a brown solid, 8.65 g, yield: 81%.

[0037] BH-5:mp 94.2 ~ 95.7 ℃. 1 H NMR (400 MHz, Chloroform- d ) δ 7.81 (d, J =1.8 Hz, 1H), 7.73 (dd, J = 8.0, 1.8 Hz, 1H), 7.28 (d, J = 7.9 Hz, 1H), 3.39 –3.30 (m, 2H), 3.25 (s, 9H), 3.04 (s, 3H), 2.71 (q, J = 3.8 Hz, 2H), 2.11 (d, J =11.3 Hz, 1H), 2.04 – 1.90 (m, 2H), 1.80 (q, J = 6.2 Hz, 2H), 1.67 (d, J = 8.4 Hz, 2H), 1.51 (dt, J= 11.4, 4.3 Hz, 1H), 1.28 (d, J = 29.3 Hz, 14H), 0.87 (t, J = 6.7Hz, 3H). 13 C NMR (101 MHz, Chloroform- d ) δ 201.02, 189.20, 151.92, 138.51,130.12, 127.79, 127.39, 125.72, 110.21, 66.99, 53.35, 50.57, 44.63, 34.72,31.81, 29.39, 29.33, 29.21, 29.16, 28.02, 26.17, 23.13, 22.65, 14.12.ESI-MS(M + ) calcd for [C 13 H 30 N + ]200.2373, found 200.2373.ESI-MS(M - ) calcd for[C 16 H 14 ClO5S - ]353.0256, found 353.0256. Example 8 Synthesis of the bicyclosulfonamide herbicide ionic liquid BH-6 According to the synthesis method of Example 6, N , N , N - Trimethyloctylammonium bromide replaced N , N , N - Trimethyldodecylammonium bromide yielded BH-6, a brown solid, 7.79 g, yield: 82%.

[0038] BH-6:mp 94.1 ~ 96.0 ℃. 1 H NMR (400 MHz, Chloroform- d ) δ 7.79 (d, J =1.8 Hz, 1H), 7.71 (dd, J = 8.0, 1.8 Hz, 1H), 7.30 – 7.21 (m, 1H), 3.41 – 3.27(m, 2H), 3.21 (d, J= 1.2 Hz, 8H), 3.03 (s, 3H), 2.82 (s, 1H), 2.70 (q, J = 3.8Hz, 2H), 2.09 (d, J = 11.4 Hz, 1H), 2.02 – 1.88 (m, 2H), 1.79 (t, J = 6.3 Hz, 2H), 1.66 (h, J = 6.7, 4.8 Hz, 2H), 1.50 (dt, J = 11.4, 4.3 Hz, 1H), 1.41 – 1.15(m, 18H), 0.86 (t, J = 6.7 Hz, 3H). 13 C NMR (101 MHz, Chloroform- d ) δ 201.25,130.16, 127.85, 127.41, 125.73, 110.32, 67.08, 53.40, 50.47, 44.63, 34.73,31.89, 29.57, 29.45, 29.34, 29.32, 29.16, 28.00, 26.17, 23.14, 22.68,14.13.ESI-MS(M + ) calcd for [C 15 H 34 N + ]228.2686, found 228.2688.ESI-MS(M - ) calcdfor [C 16 H 14 ClO5S - ]353.0256, found 353.0256. Example 9: Water solubility and particle size test Water solubility tests were performed on BH and BH-1–6, and the particle size of the solution was measured using dynamic light scattering. Following the method described in Vogel's Practical Organic Chemistry textbook, 0.1 g of sample was added to a specific volume of solvent, and the sample was sonicated at 25 °C for 5 min. Based on the volume of solvent used, three types of behavior were recorded: "soluble" for compounds dissolved in 1 mL of solvent; "limited solubility" for compounds dissolved in 3 mL of solvent; and "insoluble" for compounds not dissolved in 3 mL of solvent.

[0039] Table 1. Water solubility and particle size analysis of the ionic liquid of dicyclosulfuron herbicide.

[0040] a +: Soluble; ±: Limited solubility; : Insoluble. b Prepare a test solution with a concentration of 100 mg / L.

[0041] Table 1 shows the water solubility and particle size of the bicyclosulfuron herbicide ionic liquids. Proton-type bicyclosulfuron herbicide ionic liquids BH-1, BH-2, and BH-3 have limited solubility in water; quaternary ammonium salt-type bicyclosulfuron herbicide ionic liquids BH-4, BH-5, and BH-6 are all soluble in water; BH is insoluble in water. Dynamic light scattering tests show that the seven samples can be divided into two categories: nanoscale (BH-1, BH-2, BH-3, BH-4, BH-5, BH-6) and microscale (BH). The particle sizes of BH-1 to BH-6 are all smaller than those of BH.

[0042] The morphology of BH-5 and BH aqueous solutions was observed using a field emission scanning electron microscope (JSM-7900F). The results are as follows: Figure 4 As shown.

[0043] from Figure 4 (a) shows that BH-5 is a regular sphere and uniformly dispersed, with a size of approximately 200 nm, consistent with the results of dynamic light scattering tests. From Figure 4 (b) It can be seen that the particle size of BH after dissolving in water is greater than 1 μm, with obvious aggregation and poor dispersion. Comparison of the electron micrographs of the two substances shows that BH-5 has a smaller particle size, more uniform particles, and better dispersion than BH. Smaller particle size helps herbicide molecules penetrate plant leaves, enabling more effective absorption by plant tissues, thus improving weeding efficiency and bioavailability.

[0044] Example 10 Leaf Spreadability Test A test solution with a concentration of 100 mg / L was prepared. Surface tension was measured using the pendant drop method and contact angle was measured using the OCA20 video optical contact angle meter. Data recording and analysis are as follows: Figure 5 As shown.

[0045] Surface tension is a key factor affecting the herbicidal activity of herbicides. Herbicides with low surface tension can reduce the contact angle between droplets and weed leaf surfaces, and exhibit excellent wettability, adsorption, and penetration. Analysis Figure 5 (a) It can be seen that the surface tension of the aqueous solution of BH is comparable to that of the pure aqueous solution, while the surface tension of the aqueous solutions of BH-1 to BH-6 is lower than that of the aqueous solution of BH, with a maximum decrease of about 20 mN / m. The ionic liquid of the bicyclolsulfuron herbicide exhibits superior wetting properties and can spread better on plant leaves. AnalysisFigure 5 (b) It can be seen that, compared with BH, BH-1 to BH-6 showed a lower contact angle on rice and cotton leaves, effectively improving wetting performance, and could be better absorbed by plant leaves, thus improving bioavailability.

[0046] Example 11 Acute Aquatic Toxicity Test According to Part 12 of the Guidelines for Environmental Safety Evaluation of Chemical Pesticides: Acute Toxicity Testing in Fish (GB / T31270.12-2014), acute toxicity tests were conducted on zebrafish at three pesticide concentrations of 1, 5, and 10 mg / L. The results were based on the fish LC-5 ratio. 50 The (96h) value is used to classify the toxicity of pesticides to fish as low toxicity (LC). 50 >10 mg / L), poisoning (1.0 mg / L <LC) 50 ≤10 mg / L), highly toxic (0.1 mg / L < LC) 50 ≤1.0 mg / L), highly toxic (LC50) 50 Four levels (≤0.1 mg / L). Acute toxicity tests were conducted on zebrafish using the ionic liquid form of dicyclosulfuron-methyl herbicide, and the results are as follows: Figure 6 As shown.

[0047] according to Figure 6 Acute toxicity tests showed that at different test concentrations, the number of surviving zebrafish in aqueous solutions of BH-1, BH-2, BH-3, BH-4, and BH-5 was 10, indicating no mortality. The LC50 values ​​for zebrafish were also within acceptable limits. 50 (96 h) > 10 mg / L, acute toxicity test results showed low toxicity. Among them, although BH-3 has a carbon chain length of 12, its water solubility is limited and it did not cause mortality in zebrafish. For compound BH-6, at a test concentration of 10 mg / L and a test duration of 12 h, only 2 zebrafish survived, indicating a toxicity level of 1.0 mg / L < LC50 in zebrafish. 50 ≤10 mg / L, acute toxicity test results indicate poisoning, validating the previous work on the toxicity screening of cationic compounds for aquatic organisms.

[0048] Example 12 Arabidopsis thaliana growth inhibition test BH-1 to BH and BH were prepared into aqueous solutions with an active ingredient concentration of 1000 mg / L. 0.1 mL of each aqueous solution was mixed with 0.9 mL of growth medium to prepare a medium with a drug concentration of 100 mg / L. The growth inhibition of Arabidopsis thaliana was evaluated using the 24-well plate method described in Example 1. After 10 days of culture, the multi-well plate was photographed to observe the growth of Arabidopsis thaliana in each well. The results are shown below. Figure 7 .

[0049] Figure 7The results showed that Arabidopsis thaliana treated with BH developed albino leaves, and the seeds of Arabidopsis thaliana treated with BH-1 to BH-6 did not germinate, exhibiting excellent growth inhibition rates.

[0050] Example 13 Pre-emergence herbicidal activity test The pre-emergence herbicidal activity of BH and BH-1–6 against dicotyledonous rapeseed and monocotyledonous barnyard grass was tested using the standard petri dish method. Two sheets of filter paper were placed in a petri dish, and 10–15 seeds of barnyard grass and rapeseed were placed on the filter paper. 10 mL of the test solution was added to soak the filter paper, and the dish was incubated at 25 ℃ and 65% humidity. After 7 days of incubation, the length of roots and stems was measured, and the inhibition rate at different test concentrations (100, 50, 25, 10, 5, and 1 mg / L) was calculated. The EC50% activity was then determined. 50 EC of cyclosulfuron-methyl herbicide ionic liquid 50 The values ​​are shown in Table 2.

[0051] Table 2. Pre-emergence herbicidal activity of dicyclosulfuron-methyl ionic liquid.

[0052] Table 2 shows that BH-1 to BH-6 all exhibited superior inhibition efficiency compared to BH, and their inhibition effect on barnyard grass was better than that on rapeseed. When the alkyl chain length of the bicyclosulfuron herbicide ionic liquid was the same, BH-4 to BH-6 all showed higher root and stem inhibition rates than BH-1 to BH-3. Furthermore, the root and stem inhibition effects of BH-1 to BH-3 and BH-4 to BH-6 on both model plants gradually increased with the increase of the cationic alkyl chain length, indicating that different cationic structures are an important factor affecting weed control efficiency. Taking BH-5 as an example, its inhibition rates on the roots and stems of the dicotyledonous rapeseed were increased by approximately 5 times and 2 times, respectively, while its inhibition rates on the roots and stems of the monocotyledonous barnyard grass were increased by approximately 3 times and 5 times, respectively. As a herbicide for paddy fields, the bicyclosulfuron herbicide ionic liquid showed a significant inhibitory effect on monocotyledonous weeds, improving weed selectivity and achieving the goal of reducing application while increasing efficiency.

[0053] Example 14 Post-emergence herbicidal activity test The test methods in the People's Republic of China agricultural industry standard "Guidelines for Indoor Bioassay Tests of Pesticides - Herbicides Part 4: Activity Assay Test - Foliar Spray Method" (NY / T 1155.4-2006) were adopted. Six bicyclol sulfadiazine herbicides were prepared into 100 mg / L solutions using ionic liquid. BH was selected as a control. The weeding effect was evaluated by visual inspection and fresh weight weighing. The results are shown in Table 3.

[0054] Table 3. Post-emergence herbicidal activity of dicyclosulfuron-methyl ionic liquid.

[0055] Herbicidal activity: ++++ (≥90%); +++ (80-89%); ++ (60-79%); + (50-59%); - (<50%).

[0056] Table 3 shows that the ionic liquid form of the herbicide dicyclosulfuron-methyl exhibits better weed control efficiency against the dicotyledonous plant *Amaranthus retroflexus* than against the monocotyledonous plant *Barnyardgrass*. Compared to BH, BH-1–6 showed stronger weed control efficiency against both model plants. Specifically, the fresh weight inhibition rate against *Amaranthus retroflexus* reached as high as 90%, while the fresh weight inhibition rate against *Barnyardgrass* gradually increased with increasing carbon chain length. Under the condition of low cationic toxicity, BH-2 and BH-5 achieved inhibition rates of 83.6% and 85.4% against *Barnyardgrass*, respectively. Comparing the weed control effects of BH-5 and BH, it is clear that at the same application concentration, BH-5 has a better inhibition effect on both *Amaranthus retroflexus* and *Barnyardgrass* than BH, with inhibition rates increasing by approximately 10%, achieving the desired effect.

[0057] Example 15 Crop Safety Assessment Rice was cultivated using the method described in the People's Republic of China Agricultural Industry Standard "Guidelines for Indoor Bioassay Testing of Pesticides - Herbicides Part 8: Crop Safety Tests - Foliar Spray Method: NY / T 1155.8—2007". During the two-leaf-one-heart growth stage of rice, concentrations of 1000 mg / L and 2000 mg / L were applied respectively to observe the safety of the ionic liquid herbicide dicyclophosphamide on rice 14 days after application. The results are shown in […]. Figure 8 .

[0058] according to Figure 8 The study on rice growth showed that at application concentrations of 1000 mg / L and 2000 mg / L, BH and BH-1-6 had no effect on rice growth, and the growth was basically the same as the blank control. They did not cause any damage to rice seedlings, proving that they are safe for rice. This indicates that the ionic liquid of bicyclosulfuron herbicide can be used to control weeds in rice fields.

[0059] The above embodiments are only used to help illustrate the present invention. The implementation of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered as equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A class of bicyclic sulfadiazine herbicides in ionic liquid form, characterized in that, Its structure is shown in equation (I): Formula (I) In formula (Ⅰ), the anionic part is the anion of the active form of bicyclosulfuron; the cationic part is the protonated tertiary amine salt and quaternary ammonium salt.

2. The bicyclic sulfonamide herbicide ionic liquid compound according to claim 1, characterized in that: R1, R2, and R3 are each independently selected from -CH3 and -H, respectively, while R4 is selected from -C8H. 17 -C 10 H 21 -C 12 H 25 .

3. The bicyclic sulfadiazine herbicide ionic liquid compound according to claim 1, characterized in that: The cation portion is N , N -Dimethyloctylamine, N , N -Dimethyldecylamine, N , N -Protonated salt of dimethyldodecylamine, or N,N,N -Trimethyloctylammonium salt, N,N,N -Trimethyldecylammonium salt, N,N,N - Trimethyldodecylammonium salt.

4. The method for preparing the bicyclic sulfadiazine herbicide ionic liquid compound according to any one of claims 1-3, characterized in that: The preparation method employs two synthetic routes: synthetic route 1 is used when the cationic part is a protonated tertiary amine salt, and synthetic route 2 is used when the cationic part is a quaternary ammonium salt. The synthetic route 1 described above involves reacting a tertiary amine with the active form of bicyclosulfuron to obtain the bicyclosulfuron herbicide ionic liquid compound. The synthetic route 2 described above is to... N , N , N - Trimethylalkyl ammonium halide salt reacts with an inorganic base to give ammonium hydroxide salt, and the ammonium hydroxide salt reacts with the active form of bicyclosulfonyl ketone to give a bicyclosulfonyl ketone herbicide ionic liquid compound; N , N , N - Trimethylalkyl ammonium halides include N , N , N -Trimethylalkylammonium bromide, N , N , N -Trimethylalkylammonium chloride salt, N , N , N - Trimethylalkylammonium iodide salt.

5. The method for preparing the bicyclic sulfonamide herbicide ionic liquid compound according to claim 4, characterized in that: The synthetic route 1 includes the following steps: reacting a tertiary amine with the active form of bicyclosulfuron in a solvent to obtain a bicyclosulfuron herbicide ionic liquid compound; The synthetic route 2 includes the following steps: N , N , N - Trimethylalkyl ammonium halide salt reacts with an inorganic base in a solvent to give ammonium hydroxide salt; ammonium hydroxide salt reacts with the active form of bicyclosulfuron in a solvent to give the bicyclosulfuron herbicide ionic liquid compound.

6. The method for preparing the bicyclic sulfonamide herbicide ionic liquid compound according to claim 5, characterized in that: The solvents include anhydrous methanol, acetonitrile, tetrahydrofuran, and acetone.

7. The method for preparing the bicyclic sulfadiazine herbicide ionic liquid compound according to claim 4 or 5, characterized in that: The inorganic bases mentioned include NaOH and KOH.

8. The method for preparing the bicyclic sulfadiazine herbicide ionic liquid compound according to claim 4 or 5, characterized in that, It also includes separation and purification steps: the reaction solution containing the bicyclosulfonamide herbicide ionic liquid compound is subjected to rotary distillation to remove the solvent, then dissolved in acetone, filtered, and the acetone is removed by rotary distillation.

9. The use of the bicyclic sulfonyl herbicide ionic liquid compound according to any one of claims 1-3 in the preparation of herbicides or in the control of weeds.

10. The application according to claim 9, characterized in that: The aforementioned bicyclosulfuron herbicide ionic liquid compound can be used alone as a herbicide, or mixed with other plant protection-permitted carriers or diluents to formulate mixtures, granules, or emulsions for use, or combined with other pesticides, fungicides, insecticides, herbicides, or plant growth regulators, or used simultaneously.

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