A compound with herbicidal activity and its preparation method and application

Abstract

The present invention belongs to the field of pesticide technology and relates to a compound with herbicidal activity, its preparation method, and application. Spraying 4.5 to 9.0 g / ha of the N-pyridylbenzothiazole heterocyclic derivative on the soil before seedling emergence or 1.5 to 4.5 g / ha on the stems and leaves after seedling emergence shows good control effects on broad-leaved weeds such as Amaranthus retroflexus, Abutilon, Chenopodium album, Purslane, Veronica, and Geranium, as well as grass weeds such as Echinochloa crus-galli and Setaria viridis. Crop safety tests have shown that the N-pyridylbenzothiazole heterocyclic derivative is safe for winter wheat, rice, and corn at an application rate of 4.5 to 15.0 g / ha. The present invention provides an effective solution for the management of resistant weeds, and the N-pyridylbenzothiazole heterocyclic derivative can be developed into a herbicide with broad market prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticides, and specifically relates to a compound with herbicidal activity, and especially to an N-pyridylbenzothiazole heterocyclic derivative, a preparation method and an application thereof. Background Art

[0002] Weeds are a major factor in reducing crop yields. They compete with crops for nutrients, water, sunlight, and space, hindering field ventilation and light penetration, thereby reducing crop yield and quality. Some weeds can also secrete harmful substances that irritate plants and affect their growth.

[0003] The main methods of weed control include physical weeding, biological weeding, mechanical weeding, and chemical weeding. Physical weeding involves weeding using methods such as mulching, shading, and high temperatures. Biological weeding involves the use of animals, insects, and pathogens to control certain weeds. Mechanical weeding involves plowing, harrowing, and loosening the soil before sowing, before seedling emergence, and during various growth stages. Chemical weed control utilizes chemical herbicides, which are highly effective, labor-saving, and can eliminate the need for weeding in the field. Currently, commercially available herbicides are systematically classified into nearly 20 categories based on their chemical structure. The main herbicides include triazines, amides, ureas, dinitroanilines, diphenyl ethers, phenoxycarboxylic acids, carbamates, and organophosphates.

[0004] Weeds are a major factor contributing to crop yield losses. Currently, chemical herbicides are the primary means of weed control. With the widespread use of herbicides, weed resistance to existing chemical herbicides is increasing. Controlling resistant weeds has become a critical issue in agricultural production, and the development of herbicides with novel chemical structures and mechanisms of action is a fundamental solution.

[0005] Patent CN202310217868.6 reports a novel structural N-pyridylbenzothiazole-6-oxycarboxylic acid derivative, which exhibits high herbicidal activity against a variety of broadleaf weeds and some grass weeds.

[0006]

[0007] Patent US4898948 reports a heterocyclic substituted N-alkylbenzothiazole compound, which has certain herbicidal activity against various weeds.

[0008]

[0009] Further literature research revealed that fused heterocyclic 1,2,4,5-tetrasubstituted benzene compounds exhibited greater herbicidal activity, as reported in numerous international patents. For example, EP420194, US4640707, US5322835, US6323154, DE3922107, JP0347180, and JP62277383 report numerous fused heterocyclic tetrasubstituted benzene compounds and their formulations exhibiting herbicidal activity.

[0010] However, existing herbicides have problems such as insufficient broad-spectrum weed control, poor weed control effect, easy occurrence of phytotoxicity, and high soil residues. At the same time, with the widespread use of herbicides, weeds are becoming increasingly resistant to existing chemical herbicides. Therefore, it is of great significance to develop herbicides with novel chemical structures and mechanisms of action. Summary of the Invention

[0011] In order to solve the problems of existing herbicides such as insufficient broad-spectrum weed control, poor weed control effect, phytotoxicity and high soil residue, the present invention provides a class of compounds with novel chemical structures and excellent weed control effect.

[0012] The compound with herbicidal activity described in the present invention refers to an N-pyridylbenzothiazole heterocyclic derivative.

[0013] The N-pyridylbenzothiazole heterocyclic derivatives provided by the present invention have a good control efficacy (≥90%) against broadleaf weeds and grass weeds at an application rate of 1.5 g / ha and are crop-safe for common field crops such as winter wheat, rice, and corn. The N-pyridylbenzothiazole heterocyclic derivatives provided by the present invention are used to control weeds resistant to existing herbicides, and are particularly suitable for controlling weeds resistant to ALS inhibitors, PSII inhibitors, ACCase inhibitors, and EPSP inhibitors.

[0014] Based on the above objectives, the present invention provides N-pyridylbenzothiazole heterocyclic derivatives and their preparation methods and applications to address this need in the art.

[0015] In one aspect, the present invention relates to a compound having herbicidal activity, wherein the compound is an N-pyridylbenzothiazole heterocyclic derivative having a chemical structure as shown in formula (I),

[0016]

[0017] Wherein, the substituent Q is selected from any group of Q1 to Q3,

[0018]

[0019] In said Q1, W is selected from CH and N;

[0020] Y is selected from O, S;

[0021] Z is selected from O, CH2, NR 6 One of the NR 6 R in 6 is selected from H, C1-C6 alkyl, C3-C7 alkenyl, C3-C7 alkynyl, C2-C6 haloalkyl or C1-C6 alkoxycarbonylmethyl;

[0022] R 1 is selected from H or halogen;

[0023] R 2 is selected from H or halogen;

[0024] R 3 Selected from halogen, C1-C4 alkyl, C1-C4 haloalkyl, C1-C4 alkoxy, C1-C4 haloalkoxy, NO2;

[0025] R 4 Selected from hydrogen or C1-C6 alkyl;

[0026] R 5 Selected from hydrogen or C1-C6 alkyl.

[0027] Furthermore, in the compound provided by the present invention, the W is selected from CH, the Y is selected from O, and the Z is selected from O.

[0028] Furthermore, in the compound provided by the present invention, the R 1 Selected from F; said R 2 is selected from Cl or F; said R 3 is selected from F, Cl, CF3, NO2; said R 4 is selected from CH3; said R 5 Selected from H.

[0029] On the other hand, the present invention provides a method for preparing the above-mentioned compound, comprising: using the compound represented by formula (III) as a synthetic raw material and selecting any one of preparation routes A, B, C, D, and E;

[0030]

[0031] Furthermore, in the preparation method of the compound provided by the present invention, the preparation method of the compound represented by formula (III) is:

[0032]

[0033] In another aspect, the present invention relates to the use of any one of the above compounds in controlling weeds.

[0034] Furthermore, in the use of any one of the above compounds provided by the present invention in weed control, the compound is used for controlling grass weeds and / or broadleaf weeds.

[0035] In another aspect, the present invention relates to a herbicide comprising an N-pyridylbenzothiazole heterocyclic derivative or a salt thereof as an active ingredient. The formulation type of the herbicide is not particularly limited, and those skilled in the art may select from commonly used formulation types such as emulsifiable concentrates, suspension concentrates, dispersible oil suspensions, and wettable powders.

[0036] In another aspect, the present invention relates to a herbicide composition comprising the aforementioned N-pyridylbenzothiazole heterocyclic derivative or a salt thereof. The formulation type of the herbicide composition is not particularly limited, and those skilled in the art may select from commonly used formulation types such as emulsifiable concentrates, suspension concentrates, dispersible oil suspensions, and wettable powders.

[0037] Compared with the prior art, the present invention has the following beneficial effects or advantages:

[0038] The present invention provides the chemical structure of a class of N-pyridylbenzothiazole heterocyclic derivatives or salts thereof, herbicide compositions, and their use in weed control. These N-pyridylbenzothiazole heterocyclic derivatives or salts thereof are used to control weeds in field crop growing areas and non-cultivated crop areas. They exhibit rapid action and high herbicidal activity. They can also be used to control weeds resistant to existing herbicides, particularly those resistant to ALS inhibitors, PSII inhibitors, ACCase inhibitors, and EPSP inhibitors.

[0039] Spraying the N-pyridylbenzothiazole heterocyclic derivative on the soil before emergence at 4.5 to 9.0 g / ha or on the stems and leaves after emergence at 1.5 to 4.5 g / ha shows good control effects on broadleaf weeds such as Amaranthus retroflexus, Abutilon, Chenopodium album, Purslane, Veronica, and Geranium, as well as grass weeds such as Echinochloa crus-galli and Setaria viridis. Even at a low application dose of 1.5 g / ha, the control efficacy against various weeds reached over 90%. Crop safety tests showed that the N-pyridylbenzothiazole heterocyclic derivative was safe and had no phytotoxic effects on pre- or post-emergence winter wheat, rice, and corn at an application rate of 4.5 to 15.0 g / ha. This invention provides an effective solution for controlling resistant weeds and can be developed into a herbicide with broad market prospects. DETAILED DESCRIPTION

[0040] The technical solutions of the present invention are described below with reference to the following embodiments; however, the present invention is not limited to the following embodiments.

[0041] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments, but the embodiments are not intended to limit the present invention.

[0042] The experimental methods and detection methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0043] Example 1

[0044] This example provides a preparation route for N-pyridylbenzothiazole heterocyclic derivatives.

[0045] N-pyridylbenzothiazole heterocyclic derivative, the structure of which is shown in formula (I),

[0046]

[0047] Wherein, Q is selected from any group of Q1 to Q3,

[0048]

[0049] W is selected from one of C and N;

[0050] Y is selected from O, S;

[0051] Z is selected from O, CH2, NR 6 One of them, R 6 One selected from O, substituted or unsubstituted alkyl, alkenyl, alkynyl, and alkoxycarbonylmethyl;

[0052] R 1 is selected from H or halogen;

[0053] R 2 is selected from H or halogen;

[0054] R 3 is selected from halogen, substituted or unsubstituted alkyl, NO2;

[0055] R 4 is selected from hydrogen or alkyl;

[0056] R 5 is selected from hydrogen or alkyl.

[0057] The preparation route of N-pyridylbenzothiazole heterocyclic derivatives is as follows:

[0058]

[0059] Preparation Route A: Add ethyl 2-piperidinate and a catalytic amount of an acid-binding agent to intermediate (III) in a suitable solvent, and stir at a constant temperature for 1 to 24 hours to obtain the target compound (I-1) of general formula (I). Preferably, the solvent is toluene; preferably, the acid-binding agent is triethylamine; preferably, the molar ratio of intermediate (III) to ethyl 2-piperidinate is 1.0:1.4; preferably, the temperature is room temperature; and preferably, the reaction time is 12 hours.

[0060] Preparation Route B: Intermediate (III) is added to an appropriate solvent with ethyl hexahydropyridazine-1-carboxylate and a catalytic amount of an acid-binding agent. The reaction is stirred at a constant temperature for 1 to 24 hours to obtain intermediate (II-1). The solvent is preferably toluene; the acid-binding agent is preferably triethylamine; the molar ratio of intermediate (III) to ethyl hexahydropyridazine-1-carboxylate is preferably 1.0:1.0; the temperature is preferably room temperature; and the reaction time is preferably 12 hours.

[0061] An alkali metal salt is added to the intermediate (II-1) in a suitable solvent, heated to 30-150°C, and stirred for 1-12 hours to obtain the target compound (I-2) of general formula (I). The solvent is preferably methanol; the alkali metal salt is preferably sodium methoxide; the molar ratio of the intermediate (II-1) to the alkali metal salt is preferably 1.0:1.0; the temperature is preferably the reflux temperature of the solvent; and the reaction time is preferably 2 hours.

[0062] Preparation Route C: Add substituted 2-amino-butene-2-oic acid ethyl ester to intermediate (III) in a suitable solvent and stir at a constant temperature for 1-12 hours to obtain intermediate (II-2). Preferably, the solvent is toluene or benzene; the temperature is preferably room temperature; preferably, the molar ratio of intermediate (III) to 2-amino-butene-2-oic acid ethyl ester is 1.0:1.0; and the reaction time is preferably 1.5 hours.

[0063] An alkali metal salt is added to the intermediate (II-2) in a suitable solvent, heated to 30-150°C, and stirred for 1-12 hours to obtain the target compound (I-3) of general formula (I). The solvent is preferably toluene; the alkali metal salt is preferably sodium methoxide; the molar ratio of the intermediate (II-2) to the alkali metal salt is preferably 1.0:0.05; the temperature is preferably the reflux temperature of the solvent; and the reaction time is preferably 3 hours.

[0064] Preparation Route D: Add substituted 2-hydroxy-butene-3-oic acid ethyl ester and an acid-binding agent to intermediate (III) in a suitable solvent, heat to 30-150°C, and stir for 1-12 hours to obtain intermediate (II-3). The solvent is preferably toluene or benzene; the acid-binding agent is preferably triethylamine; the temperature is preferably at the reflux temperature of the solvent; the molar ratio of intermediate (III), 2-hydroxy-butene-3-oic acid ethyl ester, and acid-binding agent is preferably 1.0:1.0:0.5; and the reaction time is preferably 1.5 hours.

[0065] An alkali metal salt is added to the intermediate (II-3) in a suitable solvent, heated to 30-150°C, and stirred for 1-12 hours to obtain the target compound (I-4) of general formula (I). Preferably, the solvent is toluene; preferably, the alkali metal salt is sodium methoxide; preferably, the molar ratio of the intermediate (II-3) to the alkali metal salt is 1.0:1.0; preferably, the temperature is the reflux temperature of the solvent; and preferably, the reaction time is 3 hours.

[0066] Preparation Route E: Intermediate (III) is added to hexahydropyridazine in a suitable solvent and stirred at room temperature for 1-24 hours to obtain intermediate (II-4). An excess of 20% phosgene or thiophosgene in toluene is then added in the presence of a suitable acid-binding agent to obtain the target compound (I-5) of general formula (I). The preferred solvent is dichloromethane; the preferred acid-binding agent is pyridine; the preferred molar ratio of intermediate (II-4) to hexahydropyridazine is 1.0:1.0; and the preferred reaction time is 12 hours.

[0067] The preparation route of intermediate (III) is as follows:

[0068]

[0069] Potassium ethylsulfonate is added to the starting material (XI) in an appropriate solvent, heated to 30-150°C, and stirred for 1-24 hours to obtain the intermediate compound (X). The solvent is preferably N,N-dimethylformamide (DMF); preferably, the molar ratio of the starting material (XI) to potassium ethylsulfonate is 1.0:2.0; preferably, the temperature is 95°C; and preferably, the reaction time is 4.0 hours.

[0070] Add SO2Cl2 to compound (X) and stir at room temperature for a certain time to obtain compound (IX). The preferred reaction time is 2.0 h.

[0071] Compound (IX) is heated in a suitable solvent for a certain period of time to obtain compound (VIII). Preferably, the solvent is concentrated hydrochloric acid / ethanol (V / V=1 / 1); the temperature is preferably the reflux temperature of the solvent; and the reaction time is preferably 12 hours.

[0072] Compound (VIII) is added to a suitable solvent with 2-halopyridine (VII) and an acid-binding agent, heated to 30-150°C, and stirred for 1-24 hours to obtain compound (VI). The solvent is preferably N,N-dimethylformamide (DMF); the acid-binding agent is preferably K2CO3; the molar ratio of starting material (VIII), halopyridine (VII), and acid-binding agent is preferably 1.0:1.2:2.0; the temperature is preferably 120°C; and the reaction time is preferably 12 hours. The substituent X in 2-halopyridine (VII) is a leaving group, typically fluorine, chlorine, bromine, iodine, p-toluenesulfonyl, or methylsulfonyl.

[0073] Compound (VI) is prepared by adding concentrated sulfuric acid to a suitable solvent, cooling the mixture to -10°C, and slowly adding dropwise a mixed solution of concentrated sulfuric acid and nitric acid (V / V = 1 / 1). The mixture is nitrated for a desired time to obtain compound (V). The preferred solvent is chloroform or dichloromethane; the preferred mixed acid system is concentrated sulfuric acid: 68% nitric acid at a ratio of 1.0:1.0 (V / V); and the preferred reaction time is 10 to 30 minutes.

[0074] Compound (V) is added to reduced iron powder in a suitable solvent, heated to 30°C to 120°C, and stirred for 1 to 12 hours to obtain compound (IV). Preferably, the solvent is 5% glacial acetic acid aqueous solution; preferably, the molar ratio of raw material (V) to reduced iron powder is 1.0:5.0; preferably, the temperature is 60 to 80°C; and preferably, the reaction time is 3 hours.

[0075] Dissolve compound (IV) in an appropriate solvent, add it to a phosgene (thiophosgene) solution, heat to 30°C to 120°C, and stir for 1 to 12 hours to obtain intermediate (III). The solvent is preferably toluene; the temperature is preferably 90 to 95°C; and the reaction time is preferably 1 hour.

[0076] Example 2

[0077] This example provides some compounds of N-pyridylbenzothiazole heterocyclic derivatives and their specific preparation methods. The synthesis route is based on Example 1. Other N-pyridylbenzothiazole heterocyclic derivatives not mentioned can be prepared in the same way by referring to the synthesis route provided in this application.

[0078] In the structures of some compounds of N-pyridylbenzothiazole heterocyclic derivatives, R 1 , R 2 , R 3 The compounds corresponding to Q are shown in Table 1.

[0079] Table 1: R 1 , R 2 , R 3 and the group represented by Q

[0080]

[0081]

[0082]

[0083]

[0084] This example exemplifies some of the N-pyridylbenzothiazole heterocyclic derivatives No. 01 to No. 84 shown in Table 1. The listed N-pyridylbenzothiazole heterocyclic derivatives illustrate the substituents W, Y, Z, R 1 、R 2 、R 3 、R 4 、R 5 、R 6 Based on the technical enlightenment of the present invention, those skilled in the art can replace the above-mentioned substituent groups and selectively design more structural N-pyridylbenzothiazole heterocyclic derivatives.

[0085] The following examples further provide the specific steps for synthesizing the intermediates involved and the specific steps for synthesizing some N-pyridylbenzothiazole heterocyclic derivatives.

[0086] (1) Preparation of the intermediate 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-isocyanatobenzothiazol-2(3H)-one (III-1)

[0087] 1) Preparation of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-benzothiazol-2(3H)-one (VI-1)

[0088] To a 100 mL reaction flask, 276 mg (2.0 mmol) of anhydrous KCO, 5.0 mL of dry DMF solution, and 169 mg (1.0 mmol) of 6-fluorobenzothiazol-2(3H)-one (VIII-1) were added sequentially. After stirring in an oil bath at 80°C for 30 min, 238 mg (1.1 mmol) of 2,3-dichloro-5-trifluoromethylpyridine (VII-1) was added and stirred in an oil bath at 120°C for 12 h. The reaction mixture was cooled, the pH adjusted to 2-3 with 1.0 M hydrochloric acid, and extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with brine (3 × 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a crude sample. The crude sample was recrystallized from ethanol to obtain 293 mg of the product, with a yield of 84.3%. 1HNMR(400MHz, CDCl3)δ:8.74(d,J=1.6Hz,1H),8.00(d,J=1.6Hz,1H),7.56(dd,J= 6.8,4.0Hz,1H),6.51(dd,J=6.4,1.6Hz,1H),7.11(td,J=6.4,1.6Hz,1H).HRMS:C 13 H6ClF4N2OS[M+H] + Calculated value: 348.9825, measured value: 348.9830.

[0089]

[0090] 2) Preparation of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-nitrobenzothiazol-2(3H)-one (V-1)

[0091] To a 100 mL three-necked flask, 348 mg (1.0 mmol) of compound (VI-1) and 2 mL of dry dichloromethane solution were added sequentially. After the sample dissolved, 2 mL of concentrated sulfuric acid was added. The mixture was cooled to -10°C, and 0.2 mL of a 1:1 mixture of concentrated sulfuric acid and 68% nitric acid was slowly added dropwise. After stirring on ice for 30 minutes, the reaction solution was poured into ice water and stirred for another 10 minutes. After filtration and drying, 389 mg of the final product was obtained with a yield of 99%. The product was directly processed into the next step without purification.

[0092]

[0093] 3) Preparation of 5-amino-3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluorobenzothiazol-2(3H)-one (IV-1)

[0094] 280 mg of iron powder (5.0 mmol) was added to a 5% aqueous acetic acid solution (1.5 mL). The suspension was heated to 80°C, and then a solution of 393 mg (1.0 mmol) of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-nitrobenzothiazol-2(3H)-one (V-1) in 1.0 mL of acetic acid / ethyl acetate was added. The mixture was then refluxed and stirred at 60-80°C for 3 h. After cooling, water and ethyl acetate were added to the resulting mixture, which was then filtered. The filtrate was extracted with ethyl acetate, and the organic phase was washed with water and sodium bicarbonate solution, dried, and concentrated to give 345 mg of the final product in a 95% yield. The product was directly carried out to the next step without purification.

[0095]

[0096] 4) Preparation of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-isocyanatobenzothiazol-2(3H)-one (III-1)

[0097] 5.0 mL of a toluene solution containing 363 mg (1.0 mmol) of compound (IV-1) was slowly added to a 1 M phosgene / toluene solution, stirred at 90-95° C. for 1.0 h, and then concentrated under reduced pressure. The mixture was recrystallized from petroleum ether to obtain 330.1 mg of the intermediate compound (III-1) in a yield of 84.8%. 1 HNMR (400MHz, CDCl3) δ: 8.91 (d, J = 1.2Hz, 1H), 8.02 (d, J = 1.6Hz, 1H), 7.75 (d, J = 4.4Hz, 1H), 7.70 (d, J = 6.4Hz, 1H). HRMS: C 14 H5ClF4N3O2S[M+H] + Calculated value: 389.9727, measured value: 389.9732.

[0098]

[0099] (2) Preparation of 2-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-yl)-tetrahydroimidazo[1,5-a]pyridine-1,3(2H,5H)-dione (No. 01)

[0100] To a 100 mL reaction flask, 389 mg (1.0 mmol) of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-isocyanatobenzothiazol-2(3H)-one (III-1) and 220 mg (1.4 mmol) of ethyl 2-piperidinate were added, followed by 5.0 mL of dry toluene. Subsequently, a catalytic amount of triethylamine was added, and the mixture was stirred at room temperature for 12 h. The reaction mixture was diluted with water and extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with saturated sodium bicarbonate (3 × 20 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain 291 mg of the desired product in a 58.3% yield. 1 HNMR(400MHz, CDCl3)δ:8.74(d,J=1.6Hz,1H),7.98-8.00(m,2H),7.73(d,J=6.4Hz,1H),4.44(t, J=4.0Hz,1H),3.74-3.77(m,1H),3.42-3.47(m,1H),1.86-2.02(m,2H),1.59-1.75(m,4H).HRMS:C 20 H 14 ClF4N4O3S[M+H]+ Calculated value: 501.0411, measured value: 501.0405.

[0101]

[0102] (3) Preparation of 2-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-yl)tetrahydro-1H-[1,2,4]triazolo[1,2-a]pyridazine-1,3(2H)-dione (No. 03)

[0103] To a 100 mL reaction flask, 389 mg (1.0 mmol) of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-isocyanatobenzothiazol-2(3H)-one (III-1) and 158 mg (1.0 mmol) of ethyl hexahydropyridazine-1-carboxylate were added, followed by 5.0 mL of dry toluene. Subsequently, a catalytic amount of triethylamine was added, and the mixture was stirred at room temperature for 12 h. The reaction mixture was diluted with water and extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with saturated sodium bicarbonate (3 × 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to yield the intermediate ethyl 2-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-ylaminocarbonyl)-hexahydropyridazine-1-carboxylate. The intermediate was dissolved in 5.0 mL of methanol, and 54 mg (1.0 mmol) of sodium methoxide was added. The mixture was refluxed and stirred for 1.5 h. After cooling, the reaction solution was diluted with water and extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with saturated sodium bicarbonate (3 × 20 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain 271 mg of the desired product in a yield of 54.3%. 1 HNMR(400MHz, CDCl3)δ:8.74(d,J=1.6Hz,1H),8.04(d,J=4.0Hz,1H),7.99(d,J= 1.6Hz,1H),7.74(d,J=6.4Hz,1H),3.74-3.86(m,4H),1.88-1.93(m,4H).HRMS:C 19 H 13 ClF4N5O3S[M+H] + Calculated value: 502.0364, measured value: 502.0370.

[0104]

[0105] (4) Preparation of 3-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-yl)-5-(isopropylidene)oxazolidine-2,4-dione (No. 06)

[0106] To a 100 mL reaction flask, 389 mg (1.0 mmol) of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-isocyanatobenzothiazol-2(3H)-one (III-1) and 144 mg (1.0 mmol) of 2-hydroxy-butene-3-oic acid ethyl ester were added, followed by 5.0 mL of dry benzene. Subsequently, 50 mg (0.5 mmol) of triethylamine was added, and the mixture was stirred at reflux for 1.5 h. After cooling, the reaction solution was diluted with water and extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with saturated sodium bicarbonate (3 × 20 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to yield the intermediate 2-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-ylcarbamoyloxy)-3-methyl-3-butenoic acid ethyl ester. The intermediate was dissolved in 5.0 mL of toluene, and 54 mg (1.0 mmol) of sodium methoxide was added. The mixture was stirred at reflux for 3.0 h. After cooling, the reaction solution was diluted with water and extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with saturated sodium bicarbonate (3 × 20 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain 240 mg of the desired product in a yield of 49.2%. 1 HNMR (400MHz, CDCl3) δ: 8.73 (d, 1.6Hz, 1H), 8.07 (d, J = 4.0Hz, 1H), 7.99 (d, J = 1.6Hz, 1H), 7.57 (d, J = 6.4Hz, 1H), 2.05 (s, 6H). HRMS: C 19 H 11 ClF4N3O4S[M+H] + Calculated value: 488.0095, measured value: 488.0089.

[0107]

[0108] (5) Preparation of 3-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-imino)tetrahydro-[1,3,4]thiadiazolo[3,4-a]pyridazin-1(3H)-one (No. 07)

[0109] To a 100 mL reaction flask, add 86 mg (1.0 mmol) of hexahydropyridazine and 5.0 mL of anhydrous ethanol. Cool to 10°C, then slowly add 10 mL of a dichloromethane solution containing 405 mg (1.0 mmol) of 3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-5-isothiocyanatobenzothiazol-2(3H)-one (III-2) dropwise. Stir at room temperature for 4 h. Dilute with dichloromethane, wash with saturated sodium chloride (3 × 20 mL), dry over anhydrous sodium sulfate, and concentrate under reduced pressure to obtain the intermediate N-(3-(3-chloro-5-(trifluoromethyl)pyridin-2-yl)-6-fluoro-2-oxo-2,3-dihydrobenzothiazol-5-yl)hexahydropyridazine-1-carbosulfamide. Dissolve this intermediate in 5.0 mL of toluene at room temperature, and slowly add 1.0 mL of a toluene solution containing 20% ​​phosgene dropwise. The mixture was stirred for 12 h, diluted with toluene, washed with saturated sodium chloride (3×20 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain 300 mg of the target product in a yield of 58.1%. 1 HNMR(400MHz, CDCl3)δ:8.74(d,1.6Hz,1H),7.99(d,J=1.6Hz,1H),7.68(d,J=4 .0Hz,1H),7.59(d,J=6.4Hz,1H),3.83-3.99(m,4H),1.82-1.92(m,4H).HRMS:C 19 H 13 ClF4N5O2S2[M+H] + Calculated value: 518.0135, measured value: 518.0130.

[0110]

[0111] The present invention provides a synthetic route for the N-pyridylbenzothiazole heterocyclic derivative. Among them, compound (III) is an important intermediate for the synthesis of N-pyridylbenzothiazole heterocyclic derivatives. Example 1 provides a detailed description of the preparation method of intermediate (III) to try to eliminate the obstacles for those skilled in the art to understand the synthetic method shown in the present invention. Example 2 provides the preparation method of some N-pyridylbenzothiazole heterocyclic derivatives. Since this example cannot exhaustively list the synthetic methods of N-pyridylbenzothiazole heterocyclic derivatives or their salts of general formula (I) of the present invention, the above Examples 1 and 2 should not be used as limitations on the N-pyridylbenzothiazole heterocyclic derivatives and their preparation methods. Based on the technical inspiration of Examples 1 and 2, those skilled in the art can combine conventional technical means to prepare more N-pyridylbenzothiazole heterocyclic derivatives or their salts.

[0112] Example 3

[0113] This example provides a specific formulation formula for preparing N-pyridylbenzothiazole heterocyclic derivatives into emulsifiable concentrates, suspension concentrates, dispersible oil suspension concentrates and wettable powders.

[0114] (1) Herbicidal composition - emulsifiable concentrate

[0115] In this example, a herbicidal composition in the form of an emulsifiable concentrate was prepared. The addition amount of each component was expressed in weight percentage, and the active compound (No. 01) was added after being 100% reduced.

[0116] formula:

[0117]

[0118] (2) Herbicidal composition - suspension concentrate

[0119] In this example, a herbicidal composition in the form of a suspension concentrate was prepared. The amount of each component added was expressed in percentage by weight, and the active compound No. 03 was added after being 100% reduced.

[0120] formula:

[0121]

[0122]

[0123] (3) Herbicidal composition - dispersible oil suspension

[0124] In this example, a herbicidal composition in the form of a dispersible oil suspension was prepared. The amount of each component added was expressed in percentage by weight, and the active compound (No. 07) was added after being 100% reduced.

[0125] formula:

[0126]

[0127] (4) Herbicidal composition - wettable powder

[0128] In this example, a herbicidal composition in the form of a wettable powder was prepared. The amount of each component added was expressed in percentage by weight, and the active compound (No. 08) was added after being 100% reduced.

[0129] formula:

[0130]

[0131] The present invention does not particularly limit the formulation of the herbicidal composition, such as emulsifiable concentrates, suspension concentrates, dispersible oil suspensions, and wettable powders. However, those skilled in the art, incorporating conventional techniques, can readily prepare formulations suitable for agricultural use and effective in utilizing the pharmacological effects of N-pyridylbenzothiazole heterocyclic derivatives or their salts of varying structures. This will not be discussed in detail here.

[0132] Example 4

[0133] This example provides a weed control activity test for N-pyridylbenzothiazole heterocyclic derivatives.

[0134] Table 2: (Part of) the tested weed species in the examples

[0135] Chinese name Latin name abbreviation Amaranthus retroflexus Amaranthus retroflexus AMA Ramie Abutilon theophrasti ABU quinoa Chenopodium album CHE purslane Portulaca oleracea POR Veronica Veronica polita VER wild geranium Geranium carolinianum GER barnyard grass Echinochloa crusgalli ECH Setaria Setaria viridis SET

[0136] The efficacy of the pesticide in this example was evaluated using the visual inspection method in accordance with NY / T 1155.3-2006 and NY / T 1155.4-2006. The herbicidal activity of the pesticide was evaluated on a scale of 1 to 9 based on the symptoms and severity of the weeds being tested.

[0137] Level 1: All weeds died; Level 2: Equivalent to 0-2.5% of the weeds in the blank control area; Level 3: Equivalent to 2.6-5% of the weeds in the blank control area; Level 4: Equivalent to 5.1-10% of the weeds in the blank control area; Level 5: Equivalent to 10.1-15% of the weeds in the blank control area; Level 6: Equivalent to 15.1-25% of the weeds in the blank control area; Level 7: Equivalent to 25.1-35% of the weeds in the blank control area; Level 8: Equivalent to 35.1-67.5% of the weeds in the blank control area; Level 9: Equivalent to 67.6-100% of the weeds in the blank control area.

[0138] (1) Pre-emergence weed control test

[0139] The pre-emergence herbicidal activity of several N-pyridylbenzothiazole heterocyclic derivatives was evaluated according to the method described in NY / T 1155.3-2006. Each N-pyridylbenzothiazole heterocyclic derivative was prepared into a 10% emulsifiable concentrate according to the formulation described in Example 3. Soil spraying was performed one day after weed sowing, and the herbicidal efficacy was assessed 21 days after treatment. The results are shown in Table 3.

[0140] Table 3: Potted weed control experiment (soil treatment)

[0141]

[0142]

[0143] As shown in Table 3, at an application rate of 4.5 to 9.0 g / ha, the N-pyridylbenzothiazole heterocyclic derivatives provided by the present invention showed good pre-emergence weed control effects on Amaranthus retroflexus, Abutilon, Chenopodium album, Portulaca oleracea, Veronica officinalis, Geranium strychnifolium, Echinochloa crus-galli, and Setaria viridis.

[0144] (2) Post-emergence weed control test

[0145] The post-emergence herbicidal activity of several N-pyridylbenzothiazole heterocyclic derivatives was evaluated according to the method described in NY / T 1155.4-2006. Each N-pyridylbenzothiazole heterocyclic derivative was prepared into a 10% emulsifiable concentrate according to the formulation described in Example 3. Grass weeds and broadleaf weeds were sprayed at the 2- to 3-leaf stage and broadleaf weeds at the 3- to 4-leaf stage. Results were observed 21 days after treatment (see Table 4).

[0146] Table 4: Potted weed control experiment (stem and leaf spray)

[0147]

[0148]

[0149] As shown in Table 4, at an application rate of 1.5 to 4.5 g / ha, the N-pyridylbenzothiazole heterocyclic derivatives provided by the present invention showed good post-emergence weed control effects on Amaranthus retroflexus, Abutilon, Chenopodium album, Portulaca oleracea, Veronica officinalis, Geranium strychnifolium, Echinochloa crus-galli, and Setaria viridis.

[0150] (3) Crop safety evaluation test

[0151] The phytotoxicity evaluation of the tested N-pyridylbenzothiazole heterocyclic derivatives was conducted according to the method in NY / T 1965.2-2010. The evaluation was based on the fresh weight growth inhibition rate of the tested crops. The specific indicators were:

[0152] Safe, no phytotoxicity: inhibition rate is 0;

[0153] Slight phytotoxicity: inhibition rate is 1% to 10%;

[0154] Moderate phytotoxicity: inhibition rate is 11% to 30%;

[0155] Severe phytotoxicity: inhibition rate is 31% to 50%;

[0156] Severe drug damage: inhibition rate > 50%.

[0157] Crop safety evaluations were conducted using winter wheat, rice, corn, and soybeans according to the method outlined in NY / T 1965.2-2010. The N-pyridylbenzothiazole heterocyclic derivative was formulated into a 10% emulsifiable concentrate according to the formulation described in Example 3 and applied at three doses: 4.5 g / ha, 9.0 g / ha, and 15 g / ha. The results of the crop safety evaluations are shown in Table 5.

[0158] Table 5: Safety experiments

[0159]

[0160] As shown in Table 5, at a dosage of 4.5 to 15 g / ha, the N-pyridylbenzothiazole heterocyclic derivatives provided by the present invention had no significant effect on the growth of winter wheat, rice, and corn. However, at a high dosage (15 g / ha), the test compounds had a slight inhibitory effect on soybeans. This indicates that the tested N-pyridylbenzothiazole heterocyclic derivatives have good crop safety for the common field crops of winter wheat, rice, and corn.

[0161] As described above, the present invention can be better implemented. The above embodiments only describe the preferred implementation methods of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various changes and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the present invention.

Claims

1. A compound having herbicidal activity, characterized in that The compound is an N-pyridylbenzothiazole heterocyclic derivative having a chemical structure as shown in formula (I), Among them, R 1 、R 2 、R 3 The groups represented by and Q are as follows:

2. Use of the compound according to claim 1 in weed control.

3. The use according to claim 2, characterized in that The compound is used for controlling grass weeds and / or broadleaf weeds.

4. A herbicide, wherein the herbicidal active ingredient comprises the compound according to claim 1 or a salt thereof.

5. A herbicide composition, characterized in that The herbicide composition comprises the compound according to claim 1 or a salt thereof.

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