A benzamide compound containing a thiadiazole ring and preparation and application thereof

Abstract

This invention provides a benzamide compound containing a thiadiazole ring, as shown in Formula I, and its preparation and application, wherein R1 and n are defined as defined in the specification. The benzamide compound containing a thiadiazole ring disclosed in this invention exhibits excellent herbicidal activity against weeds.

Description

Technical Field

[0001] This invention belongs to the field of agricultural chemicals, specifically relating to a benzamide compound containing a thiadiazole ring, its preparation, and its application in weed control. Technical Background

[0002] For a long time, chemical herbicides have been a core means of ensuring stable agricultural production and income due to their high efficiency, convenience, and economy. However, with the long-term, single-use, and high-frequency application of herbicides, the succession of weed communities in farmland is accelerating, and herbicide resistance has evolved into a global agricultural crisis. Furthermore, traditional herbicides, due to their poor crop selectivity, long soil residue period, and disruption of soil microecology, are no longer able to meet the safety requirements of modern green agriculture. Therefore, there is an urgent need to develop new herbicides that combine high target activity, low residue, and environmental friendliness to break through the existing bottlenecks in weed control. Summary of the Invention

[0003] The purpose of this invention is to provide a novel herbicide with high target activity, low residue and environmental friendliness. Specifically, this invention discloses a benzamide compound containing a thiadiazole ring as shown in Formula I. This compound has a strong control effect on weeds and has good application prospects.

[0004] The first aspect of this invention provides a compound of formula I and a pesticide-acceptable salt thereof:

[0005]

[0006] I

[0007] in,

[0008] R1 is selected from one of halogen, C1~C8 alkyl, or halogenated C1~C8 alkyl; n is an integer from 1 to 5.

[0009] This invention also provides a method for preparing the compound of formula I and its pesticide-acceptable salt, the synthetic route of which is as follows:

[0010] ,

[0011] R1 and n are defined as in Equation I.

[0012] The present invention also discloses a herbicide containing a pesticide-acceptable salt of the compound of formula I described in the present invention as an active ingredient.

[0013] Beneficial effects

[0014] The compounds of this invention have good herbicidal activity, especially significant pre-emergence inhibition of weeds. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprising of," etc., will be understood to include the stated components or steps, without excluding the presence of other substances or steps.

[0016] Furthermore, to better illustrate the present invention, numerous specific details are provided in the following detailed embodiments.

[0017] Those skilled in the art will understand that the present invention can be practiced even without certain specific details. In some embodiments, materials, methods, and means well known to those skilled in the art are not described in detail in order to highlight the spirit of the invention.

[0018] When the compounds of the present invention can exist in tautomer form, the compounds described above and below should be understood, where applicable, to also include the corresponding tautomer forms, even if such tautomer forms are not explicitly mentioned in each case.

[0019] If the compound of Formula I described in this invention has one or more chiral centers and is therefore present as an enantiomer or diastereomer, then the pure enantiomer, the racemic version, or the diastereomer may be used in the compositions of this invention.

[0020] Any asymmetric atom (e.g., carbon, etc.) in the compounds disclosed in this invention can exist in racemic or enantiomerically enriched forms, such as (R)-, (S)-, or (R,S)- configurations.

[0021] Unless otherwise stated, all technical and technical terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. All patents and publications referenced in this disclosure are incorporated herein by reference in their entirety.

[0022] Unless otherwise stated, the following definitions shall apply as used herein. For the purposes of this disclosure, chemical elements are consistent with the CAS edition of the periodic table and the Handbook of Chemistry and Physics, 75th edition, 1994. Furthermore, general principles of organic chemistry can be found in "Organic Chemistry," Thomas Sorrell, University Science Books, Sausalito: 1999, and "March's Advanced Organic Chemistry" by Michael B. Smith and Jerry March, John Wiley & Sons, New York: 2007, the entire contents of which are incorporated herein by reference.

[0023] As used in this disclosure, the term "alkyl" refers to a saturated straight-chain or branched monovalent hydrocarbon group. When the number of carbon atoms is not used when describing "alkyl," it means that the alkyl group has any number of carbon atoms. When the number of carbon atoms is used when describing "alkyl," it means that the alkyl group has the stated number of carbon atoms. For example, an alkyl group can be C1-C1. 20 Alkyl group refers to a saturated, straight-chain or branched monovalent hydrocarbon group containing 1-20 carbon atoms, wherein the alkyl group may optionally be substituted by one or more substituents described in this disclosure. Unless otherwise specified, the alkyl group contains 1-20 carbon atoms. In some embodiments, the alkyl group contains 1-12 carbon atoms, such as "C1-C2". 12 "alkyl"; in some embodiments, the alkyl group is an alkyl group containing 1-6 (1, 2, 3, 4, 5 or 6) carbon atoms, i.e. "C1-C6 alkyl"; in still other embodiments, the alkyl group is an alkyl group containing 1-4 (1, 2, 3 or 4) carbon atoms, i.e. "C1-C4 alkyl"; in still other embodiments, the alkyl group contains 1-3 carbon atoms, i.e. "C1-C3 alkyl".

[0024] Examples of alkyl groups include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), n-propyl (n-Pr, -CH2CH2CH3), isopropyl (i-Pr, -CH(CH3)2), n-butyl (n-Bu, -CH2CH2CH2CH3), isobutyl (i-Bu, -CH2CH(CH3)2), sec-butyl (s-Bu, -CH(CH3)CH2CH3), and tert-butyl (t-B). u、-C(CH3)3), n-pentyl(-CH2CH2CH2CH2CH3), 2-pentyl(-CH(CH3)CH2CH2CH3), 3-pentyl(-CH(CH2CH3)2), 2-methyl-2-butyl(-C(CH3)2CH2CH3), 3-methyl-2-butyl(-CH(CH3)CH(CH3)2), 3-methyl-1-butyl(-CH2CH2CH(CH3)2), 2-methyl- 1-Butyl (-CH2CH(CH3)CH2CH3), n-Hexyl (-CH2CH2CH2CH2CH2CH3), 2-Hexyl (-CH(CH3)CH2CH2CH2CH3), 3-Hexyl (-CH(CH2CH3)(CH2CH2CH3), 2-Methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-Methyl-2-pentyl (-CH(CH3)CH(CH3)CH2CH) 3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3), n-heptyl, n-octyl, etc.

[0025] The term "halogenated alkyl" refers to a straight-chain or branched alkyl group, for example, substituted with one or more halogen atoms that may be the same or different from each other. For example, halogenated C1-C8 alkyl refers to a straight-chain or branched alkyl group having 1 to 8 carbon atoms, substituted with one or more halogen atoms that may be the same or different from each other. Examples include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, 2,2-difluoroethyl, 2,2-dichloroethyl, 2,2,2-trifluoroethyl, 2-fluoroethyl, 2-chloroethyl, 2-bromoethyl, 2-iodoethyl, 2,2,2-trichloroethyl, 2,2,2-tribromoethyl, 1,3-difluoro-2-propyl, 1,3-dichloro-2-propyl, 1-chloro-3-fluoro- 2-Propyl, 1,1,1-trifluoro-2-propyl, 2,3,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoro-2-propyl, 1,1,1,3,3,3-hexafluoro-2-chloro-2-propyl, 1,1,1,3,3,3-hexafluoro-2-bromo-2-propyl, 1,1,2,3,3,3-hexafluoro-2-chloropropyl, 1,1,2,3,3,3-hexafluoro-2-bromopropyl, 1,1,2,3,3,3-hexafluoro-1-bromo-2-propyl, 2,2,3,3,3-pentafluoropropyl, 3-fluoropropyl, 3-chloropropyl, 3-bromopropyl, nonafluorobutyl, nonafluoroisobutyl, nonafluorosec-butyl, or nonafluorotert-butyl, etc., but not limited to these.

[0026] The term "halogen" refers to fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0027] The term "salt" in this disclosure includes salts that have undergone acid addition, and can be salts that have undergone addition with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, or phosphoric acid, or salts that have undergone addition with an organic acid, such as formic acid, carbonic acid, acetic acid, trifluoroacetic acid, trichloroacetic acid, propionic acid, glycolic acid, thiocyanate, lactic acid, succinic acid, citric acid, benzoic acid, cinnamic acid, oxalic acid, etc., but are not limited thereto.

[0028] This disclosure also provides a method for controlling unwanted plants, the method comprising applying a herbicidal amount of the herbicidal composition of this disclosure to the unwanted plants, plant seeds and / or their growing environment.

[0029] According to embodiments of this disclosure, the term "grass" or "unwanted plant" refers to plants other than crops, such as plants that are harmful or detrimental to the growth of crops, like weeds.

[0030] According to embodiments of this disclosure, the term "growing environment" includes, but is not limited to, the growing site of unwanted plants or plant seeds or the surface of their growing medium.

[0031] According to embodiments of this disclosure, the terms "prevention" or "removal" indicate that the growth of unwanted plants is reduced by more than 10% compared to untreated unwanted plants. Preferably, the growth of unwanted plants is significantly reduced (60-79%); more preferably, the growth of unwanted plants is mostly or completely inhibited (80-100%); particularly, the growth of unwanted plants is almost completely or entirely inhibited (90-100%).

[0032] The herbicidal composition may be applied in multiple applications over time. Alternatively, the compound, its stereoisomers, or its agronomically acceptable salts, or the herbicidal composition, may be applied pre-emergence followed by post-emergence, or early post-emergence followed by mid- or late post-emergence.

[0033] According to the embodiments of this disclosure, the "unwanted plants" include, but are not limited to, one or more weed species selected from the following: species of the genera *Alternanthera*, *Commelina*, *Digitaria*, *Sorghum*, *Sedge*, etc., but are not limited to these.

[0034] As an example, the weeds are selected from one or more of the following: lotus grass, crabgrass, millet, cyperus, cogongrass, bermudagrass, purslane, amaranth, large-leaved foxtail grass, southern dodder, sedge, etc., but not limited to these.

[0035] This invention first provides compounds of formula I and pesticide-acceptable salts thereof:

[0036]

[0037] I,

[0038] in,

[0039] R1 is selected from one of halogen, C1~C8 alkyl, or halogenated C1~C8 alkyl; n is an integer from 1 to 5.

[0040] Preferably, R1 is one of halogen, C1-C6 alkyl, or halogenated C1-C6 alkyl; more preferably, it is one of methyl, ethyl, isopropyl, tert-butyl, Cl, F, Br, and CF3.

[0041] Preferably, n is 1, 2, or 3.

[0042] The preferred compounds of this invention are selected from the following compounds:

[0043] .

[0044] This invention also provides a method for preparing a compound of formula I, the synthetic route of which is as follows:

[0045] ,

[0046] R1 and n are defined as in Equation I above.

[0047] Preferably, in the above preparation method, the compound shown in Formula IV is reacted with 2-bromopropionyl chloride in a solvent at a temperature of 0–20 °C for 0.1–12 h by the action of an organic base to obtain the compound shown in Formula III, wherein the solvent is one or a mixture of the following: tetrahydrofuran, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, ethyl acetate, and 1,4-dioxane; and the organic base is triethylamine.

[0048] Preferably, in the above preparation method, the compound shown in Formula III is reacted with 4-chloro-2-fluoro-5-mercaptobenzoic acid in a solvent at a temperature of 0–20 °C for 6–12 h by the action of a base to obtain the compound shown in Formula II. The solvent is one or a mixture of the following: acetonitrile, toluene, tetrahydrofuran, N,N-dimethylformamide, and N,N-dimethylacetamide; the base is one or a mixture of the following: sodium hydroxide, cesium carbonate, and potassium carbonate.

[0049] Preferably, in the above preparation method, the compound shown in Formula II is reacted with 2-amino-5-trifluoromethyl-1,3,4-thiadiazo in a solvent at a temperature of 0–20 °C for 6–12 h by the action of a condensing agent, thereby obtaining the compound shown in Formula I. The condensing agent is one or a mixture of the following: DIC, DIEA, DCC, DMAP, EDCI, and HOBt; the organic solvent is one or a mixture of the following: cyclohexane, hexane, tetrahydrofuran, dichloromethane, 1,4-dioxane, ethyl acetate, petroleum ether, methanol, ethanol, n-propanol, carbon tetrachloride, DMF, chloroform, diethyl ether, and acetonitrile.

[0050] The present invention also provides the use of pesticide-acceptable salts of compounds of formula I in the preparation of herbicides.

[0051] The present invention also provides a herbicide containing a pesticide-acceptable salt of the compound described herein as an active ingredient.

[0052] The present invention provides a composition comprising a pesticide-acceptable salt of a compound of formula I disclosed herein as an active ingredient.

[0053] The compounds or compositions disclosed in this invention are generally used in suitable formulations appropriate for their intended use and are prepared by methods conventional in the art. For example, they can be formulated into suitable formulations such as suspensions, emulsions, liquid formulations, water-dispersible powders, granules, powders, tablets, etc.

[0054] The formulations prepared according to conventional methods in this invention can include pesticide-acceptable adjuvants. These include, but are not limited to, carriers and surfactants.

[0055] The carriers that can be used can be solid or liquid, and examples include, in particular: soybean flour, grain flour, wood flour, bark flour, sawdust, tobacco stem flour, walnut shell flour, rice bran, cellulose powder, residues from plant extraction, synthetic polymers such as powdered synthetic resins, clays (e.g., kaolin, bentonite, acid clay, etc.), talcs (e.g., talc, pyrophyllite, etc.), silica (e.g., diatomaceous earth, silica sand, mica, white carbon black (also known as hydrous silica powder, hydrous silica powder of synthetic highly dispersible silica, some products containing calcium silicate as the main component)), activated carbon, sulfur powder, pumice, sintered diatomaceous earth, brick pulverizers, fly ash, sand, inorganic mineral powders (e.g., calcium carbonate, calcium phosphate), chemical fertilizers (e.g., ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, ammonium chloride), and compost, which can be used alone or in the form of a mixture of two or more.

[0056] Examples of materials that can be used as inactive carriers in liquid form include materials that function as solvents, and materials that do not function as solvents but can disperse active ingredient compounds with the assistance of adjuvants.

[0057] Examples of inactive carriers include: water, alcohols (e.g., methanol, ethanol, isopropanol, butanol, ethylene glycol, etc.), ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, etc.), ethers (e.g., diethyl ether, dioxane, cellosol, diisopropyl ether, tetrahydrofuran, etc.), aliphatic hydrocarbons (e.g., kerosene, mineral oil, etc.), aromatic hydrocarbons (e.g., benzene, toluene, xylene, solvent oil, alkylnaphthalene, etc.), halogenated hydrocarbons (e.g., dichloromethane, chloroform, carbon tetrachloride, chlorobenzene, etc.), esters (e.g., ethyl acetate, butyl acetate, ethyl propionate, diisobutyl phthalate, dibutyl phthalate, dioctyl phthalate, etc.), amides (e.g., dimethylformamide, diethylformamide, dimethylacetamide, etc.), and nitriles (e.g., acetonitrile, etc.), which can be used alone or in mixtures of two or more.

[0058] Surfactants may be used for the purpose of emulsifying, dispersing, solubilizing and / or wetting active ingredient compounds.

[0059] Examples of surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene higher fatty acid esters, polyoxyethylene resin esters, polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monooleate, alkyl aryl sulfonates, naphthalene sulfonates, lignin sulfonates, and higher alcohol sulfonates.

[0060] In addition, adjuvants that can be used for the purpose of dispersing, stabilizing, adhering, and / or binding active ingredient compounds include casein, gelatin, starch, methylcellulose, carboxymethylcellulose, gum arabic, polyvinyl alcohol, turpentine, rice bran oil, bentonite, xanthan gum, and lignin sulfonates. Examples of adjuvants that can be used to improve the flowability of solid products include waxes, stearates, and alkyl phosphates. Adjuvants such as naphthalene sulfonate condensates or condensed phosphates can be used as suspending agents in suspensions. Defoamers such as silicone oils can also be used as adjuvants.

[0061] To control various weeds, a certain amount of the compound of the present invention, which is the effective active ingredient, is applied directly, appropriately diluted with water, or in suspension to areas where unwanted weeds are expected to appear. The dosage depends on various factors, such as the purpose, the pests to be controlled, the plant's growth status, the pest's tendency to appear, climate, environmental conditions, formulation, method of application, location of application, and time of application. The compound of the present invention, as the active ingredient, is used at a concentration of 0.01 to 5000 ppm, preferably 0.01 to 1000 ppm, and more preferably 0.1 to 100 ppm.

[0062] The compounds of this invention have a wide range of applications, and the plants or ranges to which they are applied mainly include the following categories: fruits and vegetables, such as cucumber, loofah, watermelon, cantaloupe, pumpkin, gourd, spinach, celery, cabbage, Chinese cabbage, gourd, chili pepper, eggplant, tomato, onion, ginger, garlic, leek, lettuce, green beans, cowpeas, broad beans, radish, carrot, potato, and yam; cereals, such as wheat, barley, corn, rice, and sorghum; fruit trees, such as apple, pear, banana, citrus, grape, lychee, and mango; flowers, such as peony, rose, and flamingo flower; oil crops, such as peanut, soybean, rapeseed, sunflower, and sesame; sugar crops, such as sugar beet and sugarcane; and other crops, such as strawberry, potato, sweet potato, tobacco, and tea. They can be applied to horticulture, forestry, farms, and other places where needed.

[0063] The following examples are provided to further explain the present invention. These examples are merely descriptions of the best embodiments of the present invention and do not limit the scope of the invention in any way. Unless otherwise specified, the materials, reagents, etc., used in the following examples are commercially available.

[0064] Example 1: 4-Chloro-2-fluoro-5-((1-((2-fluorophenyl)amino)-1-oxopropyl-2-yl)thio)-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)benzamide (I-01)

[0065] (1) Preparation of 2-bromo-N-(2-fluorophenyl)propionamide (intermediate 2)

[0066]

[0067] 2.22 g (20 mmol) of 2-fluoroaniline, 2.43 g (24 mmol) of triethylamine, and 40 mL of dichloromethane were added to a 150 mL single-necked flask. The mixture was stirred in an ice bath, and 4.11 g (24 mmol) of 2-bromopropionyl chloride was slowly added dropwise over approximately 10 min. After the addition was complete, the reaction was continued at room temperature for 6 h. The reaction was monitored by TLC. Once the reaction was complete, dichloromethane and sodium hydroxide solution were added, and the mixture was stirred for another 10 min. The organic phase was separated using a separatory funnel, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain the crude product, i.e., the yellow solid intermediate 2.

[0068] (2) Preparation of 4-chloro-2-fluoro-5-mercaptobenzoic acid

[0069]

[0070] 4.13 g (20 mmol) of 4-chloro-5-chlorosulfonyl-2-fluorobenzoic acid and 100 mL of toluene were added to a 500 mL single-necked flask. The mixture was stirred in an ice bath, and 15.74 g (60 mmol) of triphenylphosphine was added in portions over approximately 10 min. After addition, the reaction was continued at room temperature for 2 h. Water was then added, and the mixture was stirred for another 30 min. The organic layer was extracted with 10% sodium hydroxide (100 mL). The alkaline aqueous extract was washed with dichloromethane (100 mL), cooled in an ice bath, and acidified with hydrochloric acid to pH 2. The precipitate was filtered off. The filter cake was washed with water and dried to give 4-chloro-2-fluoro-5-mercaptobenzoic acid as a white solid, with a yield of 72%.

[0071] (3) Preparation of 4-chloro-2-fluoro-5-((1-((2-fluorophenyl)amino)-1-oxopropyl-2-yl)thio)benzoic acid (intermediate 3)

[0072]

[0073] 2.95 g (12 mmol) of intermediate 2, 3.91 g (12 mmol) of cesium carbonate, and 24 mL of acetonitrile were added to a 150 mL single-necked flask. The mixture was then stirred in an ice bath, followed by the addition of 2.07 g (10 mmol) of 4-chloro-2-fluoro-5-mercaptobenzoic acid. The reaction was continued at room temperature for 8 h. The reaction was monitored by TLC. Once the reaction was complete, the reaction mixture was concentrated under reduced pressure. The resulting solid was dissolved in water, and the aqueous phase was extracted three times with ethyl acetate (30 mL). The organic layer was extracted with 10% sodium hydroxide (50 mL), cooled in an ice bath, and acidified with hydrochloric acid to pH 2. The precipitate was filtered. The filter cake was washed with water and dried to obtain intermediate 3 as a white solid, with a yield of 43%.

[0074] (4) Preparation of 4-chloro-2-fluoro-5-((1-((2-fluorophenyl)amino)-1-oxopropyl-2-yl)thio)-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)benzamide (Ⅰ-01)

[0075]

[0076] Add 1.86 g (5 mmol) of intermediate 3, 1.15 g (6 mmol) of EDCI, 0.08 g (0.6 mmol) of HOBt and 10 mL of acetonitrile to a 150 mL single-necked flask, then stir in an ice bath. Add 1.01 g (6 mmol) of 2-amino-5-trifluoromethyl-1,3,4-thiadiazo, and continue the reaction at room temperature for 6 h. Monitor the reaction by TLC. After the reaction is complete, concentrate the reaction solution under reduced pressure. Dissolve the resulting solid in water, extract the aqueous phase three times with ethyl acetate (20 mL), dry, remove the solvent under reduced pressure, and separate by silica gel column chromatography (eluent: petroleum ether: ethyl acetate V:V = 5:1) to obtain 4-chloro-2-fluoro-5-((1-((2-fluorophenyl)amino)-1-oxopropyl-2-yl)thio)-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)benzamide (I-01). 1 H NMR (500 MHz, DMSO-d6)δ 13.96 (s, 1H), 9.97 (s, 1H), 8.04 (d, J = 7.2 Hz, 1H), 7.81 (dq, J = 8.4,3.0 Hz, 2H), 7.24 – 7.09 (m, 3H), 4.39 (q, J = 6.9 Hz, 1H), 1.51 (d, J = 7.0Hz, 3H). 13C NMR (126 MHz, DMSO-d6) δ 170.35, 169.73, 162.38 (d, J = 48.6 Hz), 158.59 (d, J = 257.8 Hz), 153.80 (d, J = 245.6 Hz), 150.75 (q, J = 37.5 Hz), 139.95 (d, J = 10.8 Hz), 134.19, 129.47, 125.74 (d, J = 7.6 Hz), 125.54 (d, J= 11.7 Hz), 124.35, 124.32, 120.80 (d, J = 13.1 Hz), 120.06 (q, J = 272.1Hz), 118.59 (d, J = 25.9 Hz), 115.51 (d, J = 19.3 Hz), 45.58, 17.82.

[0077] The compounds listed in Table 1 were prepared using the preparation method described in Example 1 above.

[0078] Table 1. Some preferred compounds of the present invention

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] Bioactivity assay

[0087] (i) Herbicidal activity test of the compounds of this invention against purslane

[0088] 1. Sample preparation

[0089] Weigh 6 mg of sample using a 0.01 g balance, dissolve it in 0.6 mL of DMSO, pipette 0.3 mL of the solution into a 50 mL beaker, and add 29.7 mL of Triton X-100 (5‰) aqueous solution to prepare 100 mg / L solutions. Further dilute to obtain 10 mg / L and 1 mg / L solutions.

[0090] 2. Testing Methods

[0091] A certain number of germinated purslane seeds were placed in a petri dish (90 mm in diameter) lined with filter paper, and 5 mL of the test solution was added to moisten the filter paper. A solvent blank control was prepared using 5 mL of Triton aqueous solution containing the same amount of DMSO. The petri dishes were incubated in an incubator (temperature 25 ± 1°C, continuous light 3000 Lux) for 5 days. The growth inhibition rate was then observed visually. Each treatment was performed in triplicate.

[0092] 3. Test results are shown in Table 2-4.

[0093] Table 2. Herbicidal activity of purslane (concentration 100 mg / L)

[0094]

[0095] 'a' represents the average of three repetitions.

[0096] Table 3. Herbicidal activity of purslane (concentration 10 mg / L)

[0097]

[0098] 'a' represents the average of three repetitions.

[0099] Table 4. Herbicidal activity of purslane (concentration 1 mg / L)

[0100]

[0101] 'a' represents the average of three repetitions.

[0102] (ii) Herbicidal activity of the compounds of this invention against Amaranthus retroflexus.

[0103] 1. Sample preparation and testing methods are the same as those used for testing the herbicidal activity of purslane.

[0104] 2. Test results are shown in Table 5.

[0105] Table 5. Herbicidal activity of compound I against Amaranthus retroflexus (concentration 100 mg / L)

[0106]

[0107] 'a' represents the average of three repetitions.

[0108] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. Compounds of Formula I and their pesticide-acceptable salts: I， in, R1 is selected from one of halogen, C1~C8 alkyl, or halogenated C1~C8 alkyl; n is an integer from 1 to 5.

2. The compound according to claim 1 and its pesticide-acceptable salts, characterized in that: R1 is one of halogen, C1-C6 alkyl, or halogenated C1-C6 alkyl, preferably one of methyl, ethyl, isopropyl, tert-butyl, Cl, F, Br, and CF3.

3. The compound according to claim 1 and its pesticide-acceptable salts, characterized in that: n is 1, 2, or 3.

4. The pesticide-acceptable salt of the compound according to any one of claims 1-3, characterized in that: Selected from the following compounds:

5. A method for preparing the compound according to any one of claims 1-4 and its pesticide-acceptable salt, characterized in that, Its synthetic route is as follows: ， Wherein, R1 and n are as defined in any one of claims 1-4.

6. The use of the compound of any one of claims 1-4 and its pesticide-acceptable salt in the preparation of herbicides.

7. A herbicide, characterized in that, The herbicide contains any one of the compounds described in 1-4 and their pesticide-acceptable salts as active ingredients.

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