Topramezone derivative and use thereof

Abstract

Disclosed in the present invention are a topramezone derivative and a use thereof. Topramezone is modified to obtain compounds I and II. By means of an anti-scouring performance indoor measurement test, an indoor biological measurement control effect test, and a corn safety indoor measurement test, compounds I and II are found to have excellent anti-scouring performance, be good for corn safety, and have excellent control effects on gramineous weeds, cyperaceae weeds, broadleaf weeds, etc., and do not affect the normal growth of corn while effective weeding is achieved. Compounds I and II can be used for killing farmland weeds during agricultural production and have a very good application and popularization value.

Description

Benpyrazone derivatives and uses thereof Technical Field

[0001] The present invention relates to fenpyrazone derivatives, in particular to fenpyrazone derivatives and uses thereof, belonging to the technical field of pesticide compounds. Background Art

[0002] Farmland weeds refer to non-cultivated plants in farmland. From an ecological and economic perspective, any plant that, under certain conditions, causes more harm than good can be considered a weed. Weeds harm crops by competing for water, fertilizer, and light, thereby affecting crop yield and quality. Many weeds also serve as intermediate hosts for pathogens and pests. Eliminating weeds is a key issue in modern agriculture, and herbicides play a crucial role in chemical control. According to statistics, the annual weed-infested area of ​​corn fields in China alone exceeds 23.33 million hectares. 2 (350 million mu), and corn losses due to weed damage reached 9.5 million tons (19 billion jin). The use of herbicides is the most economical and effective means of controlling weeds in corn fields. However, with the long-term and large-scale use of herbicides, herbicide-resistant weed species are gradually emerging.

[0003] Taking cornfield weeds as an example, there are as many as 136 species, with the dominant weeds being crabgrass, Amaranthus retroflexus, Echinochloa crusgalli, and Purslane. Chemical herbicides remain an important measure for weed control in cornfields, with commonly used herbicides including nicosulfuron, acetochlor, and benzathine. However, nicosulfuron and atrazine have long residual lives in the soil, and improper application can easily have adverse effects on subsequent crops and the environment. When the soil is dry, soil treatment agents such as acetochlor have poor control effectiveness against cornfield weeds, and with increasing years of use, weed community succession and pesticide resistance become increasingly severe. Benzathine is less effective against sedge weeds and has poor sustained control of broadleaf weeds. It is recommended that it be tank-mixed with broadleaf weed control agents such as atrazine or dicamba, which increases drug costs. Furthermore, while fenpyrazone has a certain degree of scour resistance, it is still not ideal. It can easily be washed away by rainwater and carried away by water, affecting its retention in the field and on plant leaves, resulting in a weakened or even eliminated weed control effect. Therefore, the serious infestation and difficulty of control caused by resistant weeds, the inability of commonly used herbicides to tolerate scours, and the high cost of using them have become major scientific issues that urgently need to be addressed in my country's corn production. There is an urgent need to develop new green, efficient, low-risk, scour-resistant, and economical herbicides.

[0004] In response to the above problems, the applicant has improved the structure of fenpyraclostrobin in the hope of obtaining an innovative herbicide that is effective against sedges and broadleaf weeds, is resistant to erosion, and is highly safe.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide fenpyraclostrobin derivatives and uses thereof.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] 1. A fenpyrazone derivative, or a chiral monomer or mixture thereof, a cis-trans isomer monomer or mixture thereof, or an agrochemically acceptable salt or solvate thereof, wherein the fenpyrazone derivative is selected from the group consisting of:

[0009] Compound I, whose name is: 1-((4-(3-(4,5-dihydroisoxazol-3-yl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yl)oxy)ethyl methyl carbonate, has the following structural formula:

[0010] Compound II is named: 4-(3-(4,5-dihydroisoxazol-3-yl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yl pivalate, and has the following structural formula:

[0011] 2. Use of the aforementioned fenpyrazone derivatives or chiral monomers or mixtures, cis- and trans-isomer monomers or mixtures, or agrochemically acceptable salts or solvates thereof for controlling harmful plants.

[0012] More preferably, harmful plants include but are not limited to grass weeds, sedges, and broadleaf weeds.

[0013] More preferably, the grass weeds include but are not limited to: crabgrass, goosegrass, barnyard grass, redroot barnacle, and tiger tail grass;

[0014] The sedges include but are not limited to: Cyperus rotundus;

[0015] The broadleaf weeds include but are not limited to: purslane, velvetleaf, amaranth, quinoa, amaranthus oleraceus, dayflower, field bindweed, thistle, and snakehead.

[0016] Further preferably, the harmful plants include but are not limited to: redroot barnacle, tiger tail grass, cyperus rotundus, purslane, amaranth, quinoa, amaranthus oleraceus, dayflower, field bindweed, thistle, and snakehead.

[0017] 3. A pharmaceutical composition comprising the aforementioned fenpyrazone derivative or its chiral monomer or mixture, cis-trans isomer monomer or mixture, or its agrochemically acceptable salt or solvate.

[0018] 4. Use of the aforementioned pharmaceutical composition in the preparation of herbicides.

[0019] Preferably, the herbicide is used for controlling weeds in farmland.

[0020] Preferably, the herbicide is used for controlling weeds in corn fields.

[0021] Further preferably, the varieties of corn include but are not limited to: common corn, glutinous corn, and sweet corn.

[0022] 5. A herbicide, the active ingredient of which is the aforementioned fenpyrazone derivative or its chiral monomer or mixture, cis-trans isomer monomer or mixture, or its agrochemically acceptable salt or solvate.

[0023] Preferably, the herbicide is formulated into any dosage form with the active ingredient and auxiliary ingredients of pesticide formulations allowed on pesticides, including but not limited to wettable powders, water-dispersible granules, suspensions, suspoemulsions, emulsions in water, microemulsions, aqueous solutions, emulsifiable concentrates, soluble powders, soluble liquids, granules, microcapsule suspensions, and microcapsule suspension-suspension concentrates.

[0024] 6. A herbicide comprising the aforementioned pharmaceutical composition.

[0025] Preferably, the herbicide is formulated into any dosage form using the pharmaceutical composition and auxiliary ingredients of pesticide formulations permitted on pesticides, including but not limited to wettable powders, water-dispersible granules, suspensions, suspoemulsions, emulsions in water, microemulsions, aqueous solutions, emulsifiable concentrates, soluble powders, soluble liquids, granules, microcapsule suspensions, and microcapsule suspension-suspension concentrates.

[0026] Beneficial effects of the present invention:

[0027] The applicants obtained fenpyroxene derivatives through trial and error. Compounds I and II of the present invention are modified fenpyroxene derivatives. Through indoor tests for anti-scourability, indoor bioassay efficacy, and indoor corn safety tests, the applicants surprisingly discovered that by modifying fenpyroxene derivatives, Compounds I and II of the present invention achieved unexpected effects, improving the deficiencies of existing products. These effects are primarily reflected in the following three aspects:

[0028] Indoor test for rainwater resistance: Rainwater resistance refers to the ability of herbicide spray droplets to quickly dry and penetrate leaf tissue, ensuring their continued effectiveness after rainfall. The applicant's research found that simulated rainfall 0.5 hours after application of Compound I and Compound II had little effect on weed control. However, under the same experimental conditions, rainfall 0.5, 1, and 3 hours after application of fenpyroxene significantly affected their effectiveness, while rainfall 6 hours after application had minimal effect.

[0029] The applicant has discovered that the efficacy of Compound I and Compound II of the present invention is stable at simulated rainfall intervals of 0.5 h, 1.0 h, and 3.0 h after application, indicating that Compound I and Compound II of the present invention have strong resistance to rain erosion.

[0030] Inspired by this experiment, the applicant further studied the biopreventive efficacy and safety of the compound of the present invention.

[0031] Biological control efficacy test data show that Compound I of the present invention is more effective than benzathine against the grass weeds C. rubrum and Chloris virga, with an efficacy approximately 1.5 times that of benzathine. Compound I and benzathine are equally effective against Digitaria sanguinalis, Goosegrass, and Echinochloa crusgalli. Compound II of the present invention is equally effective as benzathine against the grass weeds C. rubrum, Chloris virga, Digitaria sanguinalis, Goosegrass, and Echinochloa crusgalli.

[0032] The control effect of the compound I of the present invention on the sedge family weed Cyperus rotundus is better than that of fenpyroxil. The control effect of the compound II of the present invention on the sedge family weed Cyperus rotundus is equivalent to that of fenpyroxil.

[0033] Compound I of the present invention has a significantly better control effect on broadleaf weeds such as pigweed, Amaranthus chinensis, field bindweed, Amaranthus retroflexus, Commelina, Thistle, and Echinops chinensis than fenpyroximate, with an efficacy of about 2 times that of fenpyroximate. It also has a significantly better control effect on the broadleaf weed Portulaca oleracea than fenpyroximate, with an efficacy of about 3.8 times that of fenpyroximate. Its control effect on the broadleaf weed Abutilon is comparable to fenpyroximate. Compound II of the present invention has a comparable control effect on broadleaf weeds such as pigweed, Amaranthus chinensis, field bindweed, Amaranthus retroflexus, Commelina, Thistle, Echinops chinensis, and Amaranthus chinensis as fenpyroximate, and a superior control effect on the broadleaf weed Portulaca oleracea than fenpyroximate.

[0034] Compound I of the present invention is more effective than fenpyrazone against some grass weeds, sedge weeds, and broadleaf weeds, and has similar effects on other grass weeds. This addresses the current problems of fenpyrazone, which is poor against sedge weeds, poor sustained control of broadleaf weeds, and inability to withstand scours. Compound II of the present invention is comparable to fenpyrazone in controlling grass weeds, slightly better than fenpyrazone in controlling broadleaf weeds, and addresses the issue of fenpyrazone's inability to withstand scours.

[0035] Indoor corn safety tests showed that Compound I, Compound II and the control drug benzathine were all highly safe for corn, whether it was conventional corn Zhengdan 958, glutinous corn or sweet corn.

[0036] Therefore, the compounds I and II of the present invention can be used to kill weeds in farmland in agricultural production, and have very good application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the hydrogen spectrum of compound I;

[0038] Figure 2 is the hydrogen spectrum of compound II;

[0039] FIG3 is a test result of the anti-scour ability of fenpyrazone;

[0040] FIG4 is a test result of the anti-scour ability of compound I;

[0041] FIG5 is the anti-scour ability test result of compound II. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that the following description is only for explaining the present invention and does not limit its contents.

[0043] Example 1:

[0044] Preparation of Compound Ⅰ

[0045] To a 1L three-necked flask, fenpyroxenone (21g, 57.8mmol) and 600ml of acetonitrile (white, insoluble) were added. Potassium carbonate (16g, 115.8mmol) (yellow, insoluble) was added with stirring. 1-Chloroethyl methyl carbonate (80196-03-8) (24g, 173.2mmol) and potassium iodide (0.96g, 5.78mmol) were added with stirring at room temperature. After the addition, the temperature was raised to 85°C and the reaction was allowed to proceed for 5h. TLC confirmed the complete reaction (PE (petroleum ether): EA (ethyl acetate) = 1:1, volume ratio). The mixture was concentrated under reduced pressure, and 400ml of DCM (dichloromethane) and 400ml of water were added. The mixture was separated and extracted. The organic phase was dried over 10g of anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1, volume ratio) to obtain 22.5g of an off-white solid. The yield was 84%.

[0046] 1 H NMR (400MHz, DMSO-d6), δ (ppm): 8.012 (d, J = 8, 1H), 7.681 (d, J = 8.4, 1H), 7.496 (s, 1H), 6.535 (m, 1H), 4.473 (t, J=10, 2H), 3.674 (s, 3H), 3.644 (s, 3H), 3.346 (t, J= 10, 2H), 3.262 (s, 3H), 2.205 (s, 3H), 1.259 (d, J= 9.2, 3H).C 20 H 23 N3O8S [M+H + ] = 466.1297. (See Figure 1 for the hydrogen spectrum)

[0047] The reaction formula is as follows:

[0048] Example 2:

[0049] Preparation of Compound II

[0050] To a 250ml three-necked flask, add fenpyroxen (10.00g, 27.5mmol) and 100ml of DCM, stirring. Triethylamine (5.01g, 49.5mmol) and pivaloyl chloride (3.65g, 30.3mmol) were added at room temperature and stirred for 3h. The reaction was monitored by TLC (DCM:MeOH = 10:1, volume ratio). After the reaction was complete, the mixture was washed once with 30ml of water and separated. The organic phase was washed once with 30ml of saturated brine, dried over 10g of anhydrous sodium sulfate, filtered, and the mother liquor was concentrated to yield a yellow oil. A small amount of white solid precipitated after the addition of 40ml of n-hexane to the yellow oil. Concentration afforded a pale yellow solid. The mixture was sonicated in 40ml of n-hexane for 5min. The mixture was then stirred at room temperature (400rpm) for 16h. The mixture was filtered, rinsed with 10ml of n-hexane, and dried to dryness, yielding 11.8g of a white solid (96% yield).

[0051] 1 H NMR (400MHz, CDCl3), δ (ppm): 8.070 (d, J = 8.4, 1H), 7.570 (d, J = 8, 2H), 4.586 (t, J = 10.0,2H), 3.716(s,3H), 3.377(br,2H)3.206(s,3H), 2.289(s,3H), 1.367(s,9H).C 21 H 25 N3O6S[M+H + ] = 448.1436. (See Figure 2 for the hydrogen spectrum)

[0052] The reaction formula is as follows:

[0053] Compound I of the present invention obtained in Example 1 and Compound II of the present invention obtained in Example 2 were respectively tested with fenpyroxene (purchased from Zibo Yintai Pharmaceutical Technology Co., Ltd.) in an indoor test for anti-scourability, an indoor bioassay efficacy test, and an indoor test for corn safety. The specific methods are as follows:

[0054] 1. Indoor test of anti-scour ability

[0055] 1.1 Test basis

[0056] Refer to the Guidelines for Indoor Bioassay Tests of Pesticides for Herbicides "Part 4: Activity Determination Test: Stem-Leaf Spray Method" NY / T 1155.4-2006.

[0057] 1.2 Test conditions

[0058] The test soil was a mixture of 20 cm of loam and vermiculite in a volume ratio of 3:1. The weeds were grown in a glass greenhouse at a temperature of 25-35°C under natural light.

[0059] 1.3 Planting and management of test weeds and crops

[0060] Sow a certain amount of crabgrass seeds in a plastic pot with a diameter of 9 cm, cover with 1-2 mm of soil, put it in an enamel tray filled with water, and water it by bottom infiltration. After the water seeps to the soil surface, transfer it to a glass greenhouse for use.

[0061] 1.4 Dosage of medicine and solution preparation

[0062] Five dosages were set for compound I, compound II and the control agent benzathone, namely 3.75, 7.5, 15, 30 and 60 g active ingredient / hectare, and a blank control treatment was also added.

[0063] Accurately measure the required medicine, add it directly into water, and dilute it to the required dosage using the doubling dilution method.

[0064] 1.5 Processing design and arrangement

[0065] The experiment was conducted at the stage of crabgrass 2 leaves and 1 heart, and the stems and leaves were sprayed evenly. Indoors, ASS-4 automatic control spraying system was used for pesticide spraying, fan-shaped nozzle, combined with nozzle pressure, flow rate, etc., according to the actual spraying area (1.1m 2 ) Spray 50mL of solution (equivalent to 30L per mu), adjust the speed, evenly arrange the plastic pots to be treated on the spray table, and spray evenly. Use a spray pressure of 0.35MPa and a fan nozzle flow rate of 800mL / min. Spray from low to high volume. Repeat each treatment four times.

[0066] The anti-scour test setting is: 0.5h, 1.0h, 3.0h, and 6.0h after application, use specific shower equipment to simulate rainfall to shower the stems and leaves of the weeds that have been treated with the pesticide, and the weeds that have not been showered are used as the control.

[0067] Detailed weed damage symptoms (e.g., growth inhibition, chlorosis, deformities, etc.) were recorded 3, 7, 10, and 20 days after application, and visual comparisons of the effects of the spray were made after flushing at different time intervals. Fresh weight of the aboveground portion of each treated weed was weighed 20 days after application, and the fresh weight control efficacy was calculated.

[0068] The results of each treatment were calculated according to the following formula: weed fresh weight control effect (%) = (control fresh weight - treatment fresh weight) ÷ control fresh weight × 100. The logarithm of the pesticide dosage and the probability value of the weed fresh weight control effect were used for regression analysis using DPS statistical software to calculate the correlation coefficient and GR. 50 GR 90and 95% confidence intervals.

[0069] 1.6 Test results and analysis

[0070] The anti-scour ability test results of each agent are shown in Table 1 and Figures 3, 4, and 5.

[0071] Table 1 Comparison of anti-scour ability of each agent

[0072] As can be seen from Table 1 and Figures 3, 4 and 5, the control effect of fenpyrad was significantly reduced when rainfall occurred 0.5 h, 1.0 h and 3.0 h after application, and the control effect was basically unaffected by rainfall 6.0 h after application; however, the control effect of Compound I and Compound II of the present invention was basically unaffected by rainfall 0.5 h after application.

[0073] Compared with benzathine, the anti-scour ability of the compounds I and II of the present invention is significantly better, and there is little difference in the anti-scour ability between the compounds I and II of the present invention.

[0074] 2. Indoor bioassay efficacy test

[0075] 2.1 Experiments on various grass weeds, sedges and broadleaf weeds

[0076] 2.1.1 Test basis

[0077] Refer to the Guidelines for Indoor Bioassay Tests of Pesticides for Herbicides "Part 4: Activity Determination Test: Stem-Leaf Spray Method" NY / T 1155.4-2006.

[0078] 2.1.2 Test weeds

[0079] Grass weeds: Redroot barnacles, Tiger tail grass;

[0080] Cyperus rotundus;

[0081] Broadleaf weeds: Amaranthus retroflexus, quinoa, Amaranthus chinensis, Commelina, field bindweed, Thistle, and Snakehead.

[0082] 2.1.3 Test conditions

[0083] The test soil was a mixture of 20 cm of loam and vermiculite at a volume ratio of 3:1. The test corn was cultivated in a glass greenhouse at a temperature of 25-35°C under natural light.

[0084] 2.1.4 Planting and management of test weeds

[0085] Sow a certain amount of weed seeds in a 9cm diameter plastic pot, cover with 1-2mm of soil, place in an enamel tray filled with water, and water using bottom irrigation. After sowing, move to a glass greenhouse for cultivation and growth until use.

[0086] 2.1.5 Dosage of medicine and preparation of solution

[0087] Five doses were set for the two compounds and the control agent benzathone, namely 3.75, 7.5, 15, 30, and 60 g active ingredient / hectare, plus a blank control treatment.

[0088] Accurately measure the required medicine, add appropriate amount of emulsifier and organic solvent to dissolve it, then add a certain amount of water, and use the multiple dilution method to dilute it to the required dosage for later use.

[0089] 2.1.6 Pharmacological efficacy investigation methods and calculation formulas

[0090] The fresh weight of each treatment was measured 14 days after application. The fresh weight control efficacy was calculated using the following formula: Fresh weight control efficacy (%) = (control fresh weight - treatment fresh weight) ÷ control fresh weight × 100.

[0091] The DPS statistical software was used to conduct regression analysis on the logarithm of the dosage and the probability value of the control effect on corn fresh weight, and the correlation coefficient and GR were calculated. 50 GR 90 and 95% confidence intervals.

[0092] 2.1.7 Test results and analysis

[0093] Compound I, compound II and the control drug benzathone had obvious efficacy symptoms on the test weeds. The fresh weight control efficacy was calculated 14 days after the application, and the logarithm of the drug dosage and the probability value of the fresh weight control efficacy were regressed using DPS statistical software. The results are shown in Tables 2 and 3.

[0094] Table 2 The control effects of two new compounds on grass weeds and sedges Note: The GR value in the table is expressed as GR 50 (95% confidence interval), GR 90 (95% confidence interval)

[0095] Table 3 Control effects of two new compounds on broadleaf weeds Note: The GR value in the table is expressed as GR 50 (95% confidence interval), GR 90 (95% confidence interval)

[0096] As can be seen from Tables 2 and 3, the control effect of compound I of the present invention on the grass weeds red root barnacle and tiger tail grass is better than that of benzathine, and the efficacy is about 1.5 times that of benzathine; the control effect of compound I of the present invention on the sedge Cyperus rotundus is better than that of benzathine; the control effect of compound I of the present invention on broad-leaved weeds such as Chenopodium album, Amaranthus chinensis, Field bindweed, Amaranthus retroflexus, Commelina communis, Thistle, and Echinops serrata is significantly better than that of benzathine, and the efficacy is about 2 times that of benzathine.

[0097] As can be seen from Tables 2 and 3, the control effect of compound II of the present invention on the grass weeds Caryopteris rubra and Chloris virga is comparable to that of benzathine; the control effect of compound II of the present invention on the sedge weed Cyperus rotundus is comparable to that of benzathine; the control effect of compound II of the present invention on the broadleaf weeds such as Chenopodium album, Amaranthus chinensis, Bindweed, Amaranthus retroflexus, Commelina communis, Thistle, and Echinops spp. is comparable to that of benzathine.

[0098] The control effect of compound I of the present invention on the above-mentioned test weeds is better than that of benzathine, and the control effect of compound II of the present invention is equivalent to that of benzathine, but compound II is slightly worse than compound I.

[0099] In this efficacy test, the applicant surprisingly found that the control effect of compound I of the present invention on broadleaf weeds and sedge weeds was better than that of fenpyrotone.

[0100] 2.2 Experiments on other grass weeds and broadleaf weeds

[0101] 2.2.1 Test weeds

[0102] Grass weeds: crabgrass, goosegrass, barnyard grass;

[0103] Broadleaf weeds: Purslane, Abutilon.

[0104] 2.2.2 Test conditions

[0105] The test soil was a mixture of 20 cm of loam and vermiculite in a volume ratio of 3:1. The weeds were grown in a glass greenhouse at a temperature of 25-35°C under natural light.

[0106] 2.2.3 Planting and management of test weeds and crops

[0107] Sow a certain amount of crabgrass, goosegrass, barnyard grass, purslane, and velvet seeds in a 9-cm-diameter plastic pot, cover with 1-2 mm of soil, and place in an enamel tray filled with water. Water the pots using bottom irrigation. Once the water has seeped through the soil, transfer them to a glass greenhouse for later use.

[0108] 2.2.4 Dosage of medicine and preparation of solution

[0109] Five doses were set for the two compounds and the control agent benzathone, namely 3.75, 7.5, 15, 30, and 60 g active ingredient / hectare, plus a blank control treatment.

[0110] Accurately measure the required medicine, add it directly into water, and dilute it to the required dosage using the doubling dilution method.

[0111] 2.2.5 Treatment design and arrangement

[0112] The experiment was conducted on grass weeds at the 2-leaf 1-heart stage, velvetleaf at the 2-true-leaf stage, and purslane at the 3-5-leaf stage. The stems and leaves were sprayed evenly. The ASS-4 automatic control spraying system was used indoors for the pesticide spraying. The fan-shaped nozzles were combined with the nozzle pressure, flow rate, etc., and the actual spraying area (1.1m 2 ) Spray 50mL of solution (equivalent to 30L per mu), adjust the speed, evenly arrange the plastic pots to be treated on the spray table, and spray evenly. Use a spray pressure of 0.35MPa and a fan nozzle flow rate of 800mL / min. Spray from low to high volume. Repeat 2-4 times for each treatment.

[0113] Apply the pesticide once. After spraying, let it air dry for a day, place it in a glass greenhouse, and water it regularly to keep it moist.

[0114] 2.2.6 Weed survey methods, timing and frequency

[0115] Detailed weed damage symptoms (e.g., growth inhibition, chlorosis, deformity, etc.) were recorded 3, 7, 10, and 20 days after application, and visual comparisons of the levels of the weeds were performed. Twenty days after application, the fresh weight of the aboveground portion of each treated weed was weighed and the control efficacy was calculated.

[0116] 2.2.7 Calculation method of drug efficacy

[0117] The results of each treatment were calculated according to the following formula: weed control effect (%) = (control fresh weight - treatment fresh weight) / control fresh weight × 100.

[0118] The DPS statistical software was used to conduct regression analysis on the logarithm of the dosage and the probability of weed control effect, and the correlation coefficient and GR were calculated. 50 GR 90 and 95% confidence intervals.

[0119] 2.2.8 Test results and analysis

[0120] Observation was conducted 3 to 7 days after application. The grass weeds and broad-leaved weeds such as Portulaca oleracea treated with Compound I, Compound II and the control agent benzylpyridamole gradually turned white and dried up as they grew; the broad-leaved weeds such as Abutilon dried up and died directly.

[0121] Observation 10 days after application showed that Compound I, Compound II and the control agent benzathone had excellent treatment effects, and most of the weeds died.

[0122] Observation was conducted 20 days after application. Most of the weeds treated with compound I, compound II and the control agent benzathone dried up and died.

[0123] The control effects of compound I, compound II and the control agent benzathone on grass weeds and broadleaf weeds are shown in Tables 4 and 5. Among them, treatment 1 is compound I, treatment 2 is compound II, and treatment 3 is the control agent benzathone.

[0124] Table 4 Control effects of compound I, compound II and control agent fenpyrazone on grass weeds Note: The GR value in the table is expressed as GR 50 (95% confidence interval), GR 90 (95% confidence interval)

[0125] Table 5 Control effect of compound I, compound II and control agent fenpyrazone on broadleaf weeds Note: The GR value in the table is expressed as GR 50 (95% confidence interval), GR 90 (95% confidence interval)

[0126] As shown in Tables 4 and 5, the control effects of compound I of the present invention and benzathinesulfuron on the grass weeds Digitaria sanguinalis, Goosegrass and Echinochloa crusgalli are comparable, and both are slightly superior to compound II of the present invention; compound I of the present invention is significantly superior to benzathinesulfuron in controlling the broad-leaved weed Portulaca oleracea, with an efficacy of about 3.8 times that of benzathinesulfuron; the control effects of compound I and compound II of the present invention on the broad-leaved weed Abutilon are comparable to benzathinesulfuron; compound II of the present invention is slightly superior to benzathinesulfuron in controlling the broad-leaved weed Portulaca oleracea.

[0127] Compounds I and II of the present invention both had excellent control effects on the aforementioned weeds. Compound I of the present invention had an overall control effect superior to that of fenpyrazone on the aforementioned weeds. Compound II of the present invention had an effect comparable to that of fenpyrazone on controlling grass weeds and was slightly better than fenpyrazone on controlling broadleaf weeds.

[0128] 3. Indoor test of corn safety:

[0129] 3.1 Test crops

[0130] Three varieties of corn: Zhengdan 958, white glutinous corn, and sweet corn (Runhua sweet corn);

[0131] 3.2 Test conditions

[0132] The test soil was a mixture of 20 cm of loam and vermiculite at a volume ratio of 3:1. The test corn was cultivated in a glass greenhouse at a temperature of 25-35°C under natural light.

[0133] 3.3 Planting and management of test corn and crops

[0134] Sow a certain amount of corn seeds in a 15cm diameter plastic pot, cover with 2-3cm of soil, place in an enamel tray filled with water, and water using bottom irrigation. After sowing, move to a glass greenhouse for cultivation and growth until ready for use.

[0135] 3.4 Dosage of medicine and solution preparation

[0136] In the corn safety test, four doses of the two compounds (Compound I of the present invention and Compound II of the present invention) and the control agent fenpyrad were set, namely 15, 30, 60, and 120 g active ingredient / hectare, and a blank control treatment was also added.

[0137] Accurately measure the required medicine, add appropriate amount of emulsifier and organic solvent to dissolve it, then add a certain amount of water, and use the multiple dilution method to dilute it to the required dosage for later use.

[0138] 3.5 Treatment design and arrangement

[0139] Spray evenly on the stems and leaves of corn at the 3-4 leaf stage.

[0140] ASS-3 automatic control spraying system is used indoors for spraying of pesticides. The fan-shaped nozzle is combined with nozzle pressure, flow rate, etc. to spray the pesticide according to the actual spraying area (1.1m 2 ) Spray 50mL of solution (equivalent to 30L per mu), adjust the speed, evenly arrange the plastic pots to be treated on the spray table, and spray evenly. Use a spray pressure of 0.35MPa and a fan nozzle flow rate of 800mL / min. Spray from low to high volume. Repeat each treatment three times.

[0141] Apply the pesticide once. After spraying, let it air dry for a day, place it in a glass greenhouse, and water it regularly to keep it moist.

[0142] 3.6 Crop Survey

[0143] After application of the pesticide, investigate whether the corn in each treatment has symptoms of pesticide damage. If so, record the symptoms and levels of pesticide damage in detail. 15 days after application, measure the fresh weight of the corn in each treatment and calculate the fresh weight prevention effect to clarify the safety of the test agent on corn.

[0144] 3.7 Calculation method

[0145] The results of each treatment were calculated according to the following formula: Fresh weight protection effect (%) = (control fresh weight - treatment fresh weight) ÷ control fresh weight × 100.

[0146] 3.8 Test results

[0147] Observation 3 to 7 days after application showed that both test agents and the control drug fenpyroxene were safe to corn and the corn grew normally.

[0148] Ten days after application, the corn treated with the highest dose of the test compound I of the present invention, i.e., 120 g of active ingredient / hectare, was normal; the test compound II of the present invention and the control drug fenpyroxen were both safe for corn;

[0149] Observation 15 days after application showed that the corn grown at the highest dose of the test agent Compound I of the present invention was normal; the corn grown at the test agent Compound II of the present invention and the control agent was basically normal; in general, the three agents were highly safe for corn.

[0150] 3.8.1 Safety of Two New Compounds on Corn

[0151] (1) Safety of the compounds on the conventional corn variety Zhengdan 958 (Tables 6-1 to 6-3)

[0152] Table 6-1 Effect of Compound Ⅰ on fresh weight of corn (Zhengdan 958)

[0153] Table 6-2 Effect of Compound II on fresh weight of corn (Zhengdan 958)

[0154] Table 6-3 Effects of fenpyraclostrobin on fresh weight of corn (Zhengdan 958)

[0155] When treated with the highest dose of Compound I, i.e., 120 g of active ingredient per hectare, the growth of Zhengdan 958 corn was normal, and no phytotoxicity or fresh weight control effect was observed.

[0156] At all doses tested, including the highest dose of 120 g active ingredient / hectare, the Zhengdan 958 corn grew normally and did not suffer any phytotoxicity.

[0157] The control agent fenpyrazone and the present invention compound I showed normal growth at all test doses;

[0158] (2) Safety of Compounds on White Waxy Corn (Tables 7-1 to 7-3)

[0159] Table 7-1 Effect of Compound I on fresh weight of corn (white glutinous corn)

[0160] Table 7-2 Effect of Compound II on fresh weight of corn (white glutinous corn)

[0161] Table 7-3 Effect of fenpyraclostrobin on fresh weight of corn (white glutinous corn)

[0162] When treated with the highest dose of Compound I of the present invention and the control agent benzathone, namely 120 g active ingredient / hectare, the white waxy corn grew normally without any phytotoxicity.

[0163] All doses of the compound II of the present invention are safe to white waxy corn.

[0164] (3) Safety of compounds on sweet corn (Tables 8-1 to 8-3)

[0165] Table 8-1 Effect of Compound I on fresh weight of corn (sweet corn)

[0166] Table 8-2 Effect of Compound II on fresh weight of corn (sweet corn)

[0167] Table 8-3 Effect of fenpyraclostrobin on fresh weight of corn (sweet corn)

[0168] At the highest dose of Compound I of the present invention, i.e., 120 g of active ingredient / hectare, the sweet corn grew normally without any phytotoxicity.

[0169] All doses of the compound II of the present invention and the control agent fenpyrazone are safe to sweet corn.

[0170] 3.9 Conclusion

[0171] Overall, Compound I of the present invention, Compound II of the present invention, and the control drug benzathone are all highly safe for corn, whether it is conventional corn Zhengdan 958, glutinous corn, or sweet corn. Regardless of whether it is Zhengdan 958, glutinous corn, or sweet corn, they are all safe at the tested dose, that is, when the dosage is 120 g of active ingredient per hectare, the corn grows normally.

[0172] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A fenpyrazone derivative, or a chiral monomer or mixture thereof, a cis-trans isomeric monomer or mixture thereof, or an agrochemically acceptable salt or solvate thereof, characterized in that: The fenpyrazone derivative is selected from: Compound I, whose name is: 1-((4-(3-(4,5-dihydroisoxazol-3-yl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yl)oxy)ethyl methyl carbonate, has the following structural formula: Compound II, whose name is: 4-(3-(4,5-dihydroisoxazol-3-yl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yl pivalate, has the following structural formula:

2. Use of the benzathine derivative according to claim 1 or its chiral monomer or mixture, cis-trans isomer monomer or mixture, or its agrochemically acceptable salt or solvate for controlling harmful plants.

3. [Corrected 30.09.2024 in accordance with Rule 91] The use according to claim 2, characterized in that The harmful plants include but are not limited to grass weeds, sedges, and broadleaf weeds.

4. [Corrected 30.09.2024 in accordance with Rule 91] The use according to claim 3, characterized in that The grass weeds include but are not limited to: crabgrass, goosegrass, barnyard grass, redroot barnacles, and chloris; The sedges include but are not limited to: Cyperus rotundus; The broadleaf weeds include but are not limited to: purslane, velvetleaf, amaranth, quinoa, amaranth, dayflower, field bindweed, thistle, and channa serrata.

5. A pharmaceutical composition, characterized in that The invention comprises the benzathine derivative as claimed in claim 1 or its chiral monomer or mixture, cis-trans isomer monomer or mixture, or its agrochemically acceptable salt or solvate.

6. Use of the pharmaceutical composition according to claim 5 in the preparation of herbicides.

7. The use according to claim 6, characterized in that: The herbicide is used for controlling weeds in farmland.

8. The use according to claim 7, characterized in that: The herbicide is used for controlling weeds in corn fields.

9. A herbicide, characterized in that: The active ingredient is the fenpyrazone derivative according to claim 1 or its chiral monomer or mixture, cis-trans isomer monomer or mixture, or its agrochemically acceptable salt or solvate.

10. A herbicide, characterized in that: A pharmaceutical composition comprising the pharmaceutical composition of claim 5.

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