6-nitrogeno-cyclopicolinic acid and partial formate compound thereof as well as preparation method and application of 6-nitrogeno-cyclopicolinic acid and partial formate compound

Abstract

The invention discloses 6-nitrogeno-cyclopicolinic acid and a part of formate compounds thereof as well as a preparation method and application of the 6-nitrogeno-cyclopicolinic acid and the part of formate compounds thereof. The structural formulas of the compounds are shown as formulas I-V. The compound prepared by the invention has a novel structure and remarkable herbicidal activity; the weeding composition not only has activity on dicotyledonous weeds, but also has obvious inhibitory activity on the growth of monocotyledonous weeds; the method is short in process route, mild in reaction condition, low in equipment requirement, convenient in post-treatment and simple to operate.

Description

Technical Field

[0001] The invention relates to 6-nitrogen-containing cyclyl picolinic acid and some formate compounds thereof, as well as preparation methods and applications thereof, and belongs to the field of pesticide herbicides. Background Art

[0002] Weeds refer to plants that grow in areas that are harmful to human survival and activities. They are generally non-cultivated wild plants or plants that are harmless to humans. Chemical weeding is a method of using chemical herbicides instead of manual weeding. The main tool used is herbicides. According to morphological classification, weeds can be divided into three categories: grasses, sedges and broadleaf weeds. After being absorbed by plant roots and buds, herbicides act on specific sites, interfere with the physiological and biochemical metabolic reactions of plants, and cause plant growth inhibition or death.

[0003] Picolinic acid herbicides are a type of plant auxin herbicide that can penetrate the stems and leaves of plants and quickly conduct to the growth points, thereby binding to the auxin transporter in the plant body, causing the plant body to produce a large amount of auxin, causing the upper part of the plant to become deformed, wither, fall off leaves, necrosis, and eventually death. Picolinic acid herbicides were discovered and promoted by Dow, and a variety of picolinic acid or picolinate herbicide products have been developed so far. In the 1950s, Dow discovered the first picolinic acid herbicide, Picloram, through studying the metabolites of new nitrification inhibitors. It is mainly used in wheat fields and corn fields to control most dicotyledonous weeds. The second picolinic acid auxin herbicide, Clopyralid, was discovered in the early 1960s. It was a new type of picolinic acid herbicide obtained by Dow through structure-activity relationship (SAR) research, where the 4 and 5 positions of the pyridine ring were replaced by hydrogen atoms. Picloram was further structurally modified, and Aminopyralid was discovered in 2005. It is mainly used for lawn weeding, controlling annual or perennial broadleaf weeds, and has a long lasting effect. Over the next decade, through continuous SAR research and analysis of soil metabolites, Dow discovered that the introduction of phenyl groups into the 6-position of the pyridine ring and methoxy groups into the benzene ring could greatly enhance the herbicidal activity of the parent compound and improve the degradation characteristics of the new compound in the soil. Finally, the aryl picolinate herbicides Halauxifen-methyl and Florpyrauxifen-benzyl were discovered. Halauxifen-methyl was first registered and listed in my country in 2014. It is mainly used in wheat fields to control broadleaf weeds, and also to control resistant weeds, such as resistant cleavers, shepherd's purse, and sophora flavescens.

[0004]

[0005] However, most of these known picolinic acid herbicides are effective in controlling dicotyledonous broadleaf weeds, and except for clopyralid, the other picolinic acid herbicides have poor control effects on grass plants. Therefore, picolinic acid compounds with high efficiency and broad-spectrum herbicidal activity need to be further developed. Summary of the invention

[0006] In order to expand the weed control range of existing picolinic acid herbicides and reduce the damage of such compounds to crops, the present invention provides a 6-nitrogen-containing cyclyl picolinic acid and some formate compounds thereof and their preparation methods and applications. In the synthesis of such compounds, by improving the structure of amiloride, different substituted nitrogen-containing cyclyl substituents are introduced to improve the weed control performance of picolinic acid compounds. The present invention has a novel structure, a relatively broad spectrum of weed control activity, a short synthetic route, mild reaction conditions, and a simple preparation method.

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

[0008] In the first aspect, the present invention provides compounds represented by the following formula I, formula I', formula II, formula III, formula IV or formula V:

[0009]

[0010] In Formula I, Formula I', Formula II, Formula III, Formula IV and Formula V, R is selected from any one of hydrogen, halogen, halogen-substituted or unsubstituted C1-C6 straight or branched alkyl, C1-C6 alkoxy, and amino;

[0011] In Formula I, R1 is selected from hydrogen, C1-C6 straight chain or branched alkyl, substituted or unsubstituted benzene ring, wherein the substituents in the substituted benzene ring are one or more, and the substituents in the substituted benzene ring are each independently selected from any one of halogen, C1-C6 straight chain or branched alkyl, halogen-substituted C1-C6 straight chain or branched alkyl, and C1-C6 alkoxy;

[0012] In formula Ⅰ', R1' is (CH2) n , n is any natural number from 1 to 4.

[0013] Preferably, in Formula I to Formula V, R is any one of hydrogen, halogen, methyl, trifluoromethyl, methoxy, and amino;

[0014] In Formula I, R1 is selected from hydrogen, C1-C3 straight chain or branched alkyl, substituted or unsubstituted benzene ring, wherein the substituent in the substituted benzene ring is para-substituted, and the substituent is selected from any one of halogen, C1-C3 straight chain or branched alkyl, C1-C3 straight chain or branched alkoxy;

[0015] In formula Ⅰ', R1' is (CH2) n , n is any natural number between 3 and 4.

[0016] The compound represented by Formula I may specifically be any one of the following Formulas I-1 to I-20: Formula I-1: R1 = Ph; R = H; Formula I-2: R1 = 4-CH3-Ph; R = H; Formula I-3: R1 = 4-F-Ph; R = H; Formula I-4: R1 = 4-OCH3-Ph; R = H; Formula I-5: R1 = CH3; R = H; Formula I'-6*: R1 = (CH2)4; R = H; Formula I-7: R1 = H; R = 4-CH3; Formula I-8: R1 = H; R = 5-CH3; Formula I-9: R1 = H; R = 6-CH3; Formula I-10: R1 = H; R = 7-CH3; Formula I-11: R1 = H;

[0017] R=4-F; Formula I-12: R1=H; R=5-F; Formula I-13: R1=H; R=6-F; Formula I-14: R1=H; R=7-F; Formula I

[0018] -15: R1=H; R=4-Cl; Formula I-16: R1=H; R=5-Cl; Formula I-17: R1=H; R=6-Cl; Formula I-18: R1=H; R=7-Cl; Formula I-19: R1=H; R=5-Br; Formula I-20: R1=H; R=6-Br.

[0019] That is, the compound represented by formula Ⅰ' can be specifically a compound represented by the following formula Ⅰ'-6:

[0020] Formula I'-6: R1 = (CH2)4; R = H;

[0021]

[0022] The compound represented by formula II can specifically be any one of the following formulas II-1 to II-18: Formula II-1: R = H; Formula II-2: R = 4-CH3; Formula II-3: R = 5-CH3; Formula II-4: R = 6-CH3; Formula II-5: R = 4-F; Formula II-6: R = 5-F; Formula II-7: R = 6-F; Formula II-8: R = 4-Cl; Formula II-9: R = 5-Cl; Formula II-10: R = 6-Cl; Formula II-11: R = 4-Br; Formula II-12: R = 5-Br; Formula II-13: R = 6-Br; Formula II-14: R = 4-NH2; Formula II-15: R = 6-NH2; Formula II-16: R = 4-OCH3; Formula II-17: R = 5-OCH3; Formula II-18: R = 6-OCH3.

[0023] The compound represented by formula III can be specifically any one of the following formulas III-1 to III-24: formula III-1: R = H; formula III-2: R = 4-CH3; formula III-3: R = 5-CH3; formula III-4: R = 6-CH3; formula III-5: R = 7-CH3; formula III-6: R = 4-F; formula III-7: R = 5-F; formula III-8: R = 6-F; formula III-9: R = 7-F; formula III-10: R = 4-Cl; formula III-11: R = 5-Cl; formula III-12: R = 6- Cl; Formula III-13: R = 7-Cl; Formula III-14: R = 4-Br; Formula III-15: R = 5-Br; Formula III-16: R = 6-Br; Formula III-17: R = 7-Br; Formula III-18: R = 4-NH2; Formula III-19: R = 6-NH2; Formula III-20: R = 7-NH2; Formula III-21: R = 4-OCH3; Formula III-22: R = 5-OCH3; Formula III-23: R = 6-OCH3; Formula III-24: R = 7-OCH3.

[0024] The compound represented by formula IV can specifically be any one of the following formulas IV-1 to IV-11: Formula IV-1: R = 4-CH3; Formula IV-2: R = 5-CH3; Formula IV-3: R = 4-F; Formula IV-4: R = 5-F; Formula IV-5: R = 4-Cl; Formula IV-6: R = 5-Cl; Formula IV-7: R = 4-Br; Formula IV-8: R = 5-Br; Formula IV-9: R = 4-OCH3; Formula IV-10: R = 5-OCH3; Formula IV-11: R = 5-CF3.

[0025] The compound represented by formula V can specifically be any one of the following formulas V-1 to V-11: formula V-1: R = 4-CH3; formula V-2: R = 5-CH3; formula V-3: R = 4-F; formula V-4: R = 5-F; formula V-5: R = 4-Cl; formula V-6: R = 5-Cl; formula V-7: R = 4-Br; formula V-8: R = 5-Br; formula V-9: R = 4-OCH3; formula V-10: R = 5-OCH3; formula V-11: R = 5-CF3.

[0026] In the present invention, the C1-C6 straight chain or branched alkyl group includes C1, C2, C3, C4, C5, C6 straight chain or branched alkyl groups, illustratively including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, etc.

[0027] The halogen may specifically be fluorine, chlorine, bromine or iodine.

[0028] The C1-C6 alkoxy group includes C1, C2, C3, C4, C5, C6 straight chain or branched alkoxy groups, and illustratively includes but is not limited to methoxy, ethoxy, propoxy, isopropoxy, butoxy and other C1-C4 alkoxy groups.

[0029] In a second aspect, the present invention provides a method for preparing the compound described in any one of the above items, which is the following method A, method B or method C:

[0030] Method A, wherein the compound is a compound of formula I or a compound of formula I', comprises the following steps:

[0031] 1) Protecting the amino group of the compound represented by formula A1 with a phthaloyl group to obtain a compound represented by formula A2;

[0032]

[0033] 2) Fluorinating the compound represented by formula A2 to obtain a compound represented by formula A3;

[0034]

[0035] 3) When the target product is a compound of formula I, reacting the compound of formula A4 with the compound of formula A5 to obtain a compound of formula A6;

[0036]

[0037] In Formula A4, Formula A5 and Formula A6, R and R1 are defined as in Formula I;

[0038] When the target product is a compound represented by formula Ⅰ', reacting the compound represented by formula A4' with the compound represented by formula A5 to obtain a compound represented by formula A6';

[0039]

[0040] In Formula A4' and Formula A6', R and R1' are defined the same as in Formula I';

[0041] 4) When the target product is a compound of formula I, reacting the compound of formula A3 with the compound of formula A6, and separating them after the reaction is complete to obtain a compound of formula A7;

[0042]

[0043] When the target product is a compound represented by formula Ⅰ', the compound represented by formula A3 is reacted with the compound represented by formula A6' to obtain a compound represented by formula A7';

[0044]

[0045] 5) When the target product is a compound of formula I, removing the phthaloyl protection of the compound of formula A7 to obtain a compound of formula A8;

[0046]

[0047] When the target product is a compound represented by Formula Ⅰ', the phthaloyl protection of the compound represented by Formula A7' is removed to obtain a compound represented by Formula A8';

[0048]

[0049] 6) When the target product is a compound of formula I, hydrolyzing the compound of formula A8 to obtain a compound of formula I;

[0050] When the target product is a compound represented by formula Ⅰ', the compound represented by formula A8' is hydrolyzed to obtain a compound represented by formula Ⅰ';

[0051] Method B, wherein the compound is a compound of formula II or a compound of formula III, comprises the following steps:

[0052] 1) subjecting the compound represented by formula B1 to a nucleophilic substitution reaction with hydrazine hydrate to obtain a compound represented by formula B2;

[0053]

[0054] In Formula B1 and Formula B2, R is defined the same as Formula II or Formula III;

[0055] 2) subjecting the compound represented by formula B2 to a nucleophilic substitution reaction with hydrazine hydrate and ring closure to obtain a compound represented by formula B3;

[0056]

[0057]

[0058] 3) subjecting the compound represented by formula B3 to a nucleophilic substitution reaction with the compound represented by formula B4, and separating them after the reaction is complete to obtain a compound represented by formula B5 and a compound represented by formula B6;

[0059]

[0060] 4) hydrolyzing the compound represented by formula B5 and the compound represented by formula B6 respectively to obtain the compound represented by formula II and the compound represented by formula III;

[0061] Method C, wherein the compound is a compound of formula IV or a compound of formula V, comprising the following steps:

[0062] 1) protecting the compound represented by formula C1 by phthaloyl to obtain the compound represented by formula C2;

[0063]

[0064] 2) subjecting the compound represented by formula C2 to a nucleophilic substitution reaction with the compound represented by formula C3 to obtain a compound represented by formula C4;

[0065]

[0066] In Formula C3 and Formula C4, R is defined the same as Formula IV or Formula V;

[0067] 3) removing the phthaloyl protection of the compound represented by formula C4 to obtain the compound represented by formula C5;

[0068]

[0069]

[0070] 4) hydrolyzing the compound represented by formula C5 to obtain the compound represented by formula IV;

[0071] 5) The compound represented by formula IV is subjected to methyl esterification reaction with methanol to obtain the compound represented by formula V.

[0072] Furthermore, in the method A, in step 1), the step of protecting the phthaloyl group comprises: reacting the compound represented by formula A1 with phthaloyl chloride in an organic solvent under the action of a catalyst to obtain a compound represented by formula A2;

[0073] The molar ratio of the compound represented by formula A1 to the phthaloyl chloride is 1:(1-2), such as 1:1.5;

[0074] The catalyst is at least one of 4-dimethylaminopyridine, triethylamine and diisopropylethylamine, such as 4-dimethylaminopyridine and triethylamine in a molar ratio of 1:30, wherein the molar ratio of the compound represented by formula A1 to 4-dimethylaminopyridine is 10:1;

[0075] The organic solvent is acetonitrile, dimethylformamide or dimethyl sulfoxide;

[0076] The reaction temperature in step 1) is 20-100°C (20-25°C) and the reaction time is 1-6h (e.g. 2h);

[0077] The fluorination step in step 2) comprises: subjecting the compound represented by formula A2 to a fluorination reaction with potassium fluoride to obtain a compound represented by formula A3;

[0078] The molar ratio of the compound represented by formula A2 to the potassium fluoride is 1:(1-1.5), such as 1:1.1;

[0079] The fluorination reaction temperature is 20-50°C and the reaction time is 18-24 hours, such as reacting at room temperature for 24 hours;

[0080] In step 3), the reaction is carried out in the presence of cyanuric chloride;

[0081] The molar ratio of the compound represented by formula A4 to the compound represented by formula A5 and cyanuric chloride is 1:(1-1.3):0.1, such as 1:1:0.1;

[0082] The molar ratio of the compound represented by formula A4' to the compound represented by formula A5 and cyanuric chloride is 1:(1-1.3):0.1, such as 1:1:0.1;

[0083] In step 3), the reaction temperature is 50-80°C and the reaction time is 2-4 hours, such as reacting at 75°C for 2 hours;

[0084] The reaction in step 4) is carried out in the presence of NaH;

[0085] The molar ratio of the compound represented by formula A3, the compound represented by formula A6, and NaH is 1:(1.5-2):(1.6-2.1), specifically 1:1.5:1.6;

[0086] The molar ratio of the compound represented by formula A3, the compound represented by formula A6', and NaH is 1:(1.5-2):(1.6-2.1), specifically 1:1.5:1.6;

[0087] Step 4) the reaction is carried out under the protection of an inert gas, such as argon;

[0088] In step 4), the reaction is carried out in ultra-dry 1,4-dioxane;

[0089] In step 4), the reaction temperature is 70-100°C and the reaction time is 18-24 hours. For example, NaH and the compound represented by formula A6 are first reacted at 70°C for 3 hours, and then a mixture of formula A3 and formula A3' is added, and the temperature is raised to 100°C and the reaction is continued for 20 hours;

[0090] The step of removing the phthaloyl protection in step 5) comprises: reacting the compound represented by formula A7 or the compound represented by formula A7' with hydrazine hydrate;

[0091] The molar ratio of the compound represented by formula A7 or the compound represented by formula A7' to hydrazine hydrate is 1:(100-200), specifically 1:150;

[0092] The reaction in step 5) is carried out in ethanol, propanol or tetrahydrofuran;

[0093] In step 5), the reaction temperature is 20-40° C. and the reaction time is 1-3 hours, such as reacting at room temperature (20-25° C.) for 2 hours;

[0094] In step 6), the hydrolysis is carried out under alkaline or acidic conditions;

[0095] The alkaline condition is provided by KOH, the hydrolysis temperature is 80-110° C., and the time is 10-25 hours, such as reflux overnight at 100° C.

[0096] Further, in the method B, the molar ratio of the compound represented by formula B1 in step 1) to the hydrazine hydrate is 1:(1-2), such as 1:2;

[0097] The organic solvent for the reaction in step 1) is tetrahydrofuran, dioxane or toluene;

[0098] In step 1), the reaction temperature is 60-100° C. and the reaction time is 2-4 hours, such as reacting at 65° C. for 2 hours;

[0099] The reaction in step 2) is carried out in the presence of an alkaline salt, sodium bicarbonate, and the molar ratio of the compound represented by formula B2 to sodium bicarbonate is 1:(2-3), such as 1:2;

[0100] In step 2), the hydrazine hydrate is 100% hydrazine hydrate;

[0101] In step 2), the reaction temperature is 100° C. and the reaction time is 4 to 8 hours, such as 6 hours;

[0102] In step 3), the molar ratio of the compound represented by formula B3, the compound represented by formula B4, and NaH is (1-1.5):1:(1.1-1.6), such as 1:1:1.1;

[0103] In step 3), the reaction is carried out in ultra-dry 1,4-dioxane;

[0104] In step 3), the reaction temperature is 70-100° C. and the reaction time is 18-24 hours. For example, NaH and the compound represented by formula B3 are first reacted at 50° C. for 3 hours, and then the compound represented by formula B4 is added and reacted at 100° C. for 24 hours.

[0105] The hydrolysis in step 4) is carried out under alkaline or acidic conditions;

[0106] The acidic condition is provided by 80% concentrated sulfuric acid, the hydrolysis temperature is 80-110° C. (such as 100° C.), and the time is 1-5 hours, such as 3 hours.

[0107] Furthermore, in the method C, the step of protecting the phthaloyl group in step 1) comprises: reacting the compound represented by formula C1 with phthaloyl chloride in an organic solvent under the action of a catalyst to obtain a compound represented by formula C2;

[0108] The molar ratio of the compound represented by formula C1 to the phthaloyl chloride is 1:(1-2), such as 1:1.5;

[0109] The catalyst is at least one of 4-dimethylaminopyridine, triethylamine and diisopropylethylamine, such as 4-dimethylaminopyridine and triethylamine in a molar ratio of 1:30, wherein the molar ratio of the compound represented by formula A1 to 4-dimethylaminopyridine is 10:1;

[0110] The organic solvent is acetonitrile, dimethylformamide or dimethyl sulfoxide;

[0111] The reaction temperature in step 1) is 20 to 100° C. (e.g., 20 to 25° C.) and the reaction time is 1 to 6 hours;

[0112] In step 2), the molar ratio of the compound represented by formula C2, the compound represented by formula C3, and NaH is (1-1.5):1:(1.1-1.6), such as 1:1:1.1;

[0113] The reaction in step 2) is carried out in ultra-dry 1,4-dioxane;

[0114] In step 2), the reaction temperature is 70-100° C. and the reaction time is 18-24 hours. For example, NaH and the compound represented by formula C3 are first reacted at 50° C. for 3 hours, and then the compound represented by formula C2 is added and reacted at 100° C. for 24 hours.

[0115] The step of removing the phthaloyl protection in step 3) comprises: reacting the compound represented by formula C4 with hydrazine hydrate to obtain the compound represented by formula C5;

[0116] The molar ratio of the compound represented by formula C4 to hydrazine hydrate is 1:(100-200), specifically 1:173;

[0117] The reaction in step 3) is carried out in ethanol, propanol or tetrahydrofuran;

[0118] In step 3), the reaction temperature is 20-40°C and the reaction time is 1-3 hours, such as reacting at room temperature for 2 hours;

[0119] The hydrolysis in step 4) is carried out under alkaline or acidic conditions;

[0120] The alkaline condition is provided by KOH, the hydrolysis temperature is 80-110°C, and the time is 10-25h, such as reflux overnight at 100°C;

[0121] The reaction in step 5) is carried out in the presence of thionyl chloride, and the molar ratio of the compound represented by formula IV to thionyl chloride is 1:(1.5-3), such as 1:2;

[0122] The ratio of the compound represented by formula IV to methanol is 1 mmol: (5-15) mL, such as 1 mmol: 10 mL;

[0123] In step 5), the reaction temperature is 40-60° C. and the reaction time is 1-2 hours, such as reacting at 40° C. for 2 hours.

[0124] In a third aspect, the present invention provides the use of any of the above compounds in any of the following:

[0125] R1) inhibit weed growth;

[0126] R2) inhibit root development of weed seeds;

[0127] R3) Preparation of herbicides.

[0128] In the above application, the weeds are dicotyledonous weeds and / or monocotyledonous weeds.

[0129] Specifically, the dicotyledonous weeds are any one of Arabidopsis thaliana, velvetleaf, quinoa, Amaranthus reflexus, Purslane, Plantain, Artemisia selengensis, Pigweed, Morning Glory and Taraxacum officinale;

[0130] The monocotyledonous weeds are any one of wild oats, foxtail grass, barnyard grass and crabgrass.

[0131] In a fourth aspect, the present invention provides a herbicide, the active ingredient of which is any one of the compounds described above.

[0132] The present invention has the following advantages:

[0133] The compound prepared by the present invention has a novel structure and significant herbicidal activity; it is not only active against dicotyledonous weeds, but also has significant inhibitory activity against the growth of monocotyledonous weeds. In addition, the present invention has a short synthesis route, mild reaction conditions, low equipment requirements, convenient post-treatment, and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0134] Figure 1 The present invention is a reaction flow chart for preparing a 6-substituted indole picolinic acid compound represented by formula I.

[0135] Figure 2 The following is a reaction flow chart for preparing the compound represented by formula I'-6 according to the present invention.

[0136] Figure 3The present invention provides a reaction flow chart for preparing 6-substituted-1H-indazolyl pyridine carboxylic acid compounds and 6-substituted-2H-indazolyl pyridine carboxylic acid compounds represented by formula II and formula III.

[0137] Figure 4 The present invention provides a reaction flow chart for preparing the compounds of formula IV and the 6-(substituted 7-azaindolyl)picolinic acid compounds and 6-(substituted 7-azaindolyl)picolinic acid ester compounds shown in formula IV. DETAILED DESCRIPTION

[0138] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0139] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0140] The experimental scheme for synthesizing the compound shown in formula I is as follows:

[0141] according to Figure 1 The synthesis of the compound of formula I is described in detail below using the synthesis of 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)-picolinic acid as an example.

[0142] Synthesis Example 1. Synthesis of the derivative 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)picolinic acid Step A: Preparation of 3,5,6-trichloro-4-phthalimidopyridinemethylnitrile

[0143]

[0144] In a 500mL three-necked round-bottom flask, add acetonitrile (200mL), 4-aminoamino-3,5,6-trichloro-2-pyridinemethylnitrile (22.2g, 0.1mol), 4-dimethylaminopyridine (1.22g, 0.01mol), and triethylamine (30.4g, 0.3mol) in sequence. After stirring and dissolving, control the reaction temperature below 0°C, slowly add phthaloyl chloride (30.45g, 0.15mol), and after the addition is complete, warm to room temperature and react for 2 hours. Pour the reaction solution into 1000mL of water, filter and dry to obtain light yellow 3,5,6-trichloro-4-phthalimidopyridinemethylnitrile (35.1g, 0.099mol), with a yield of 99%.

[0145] 1 H NMR (500MHz, Chloroform-d) δ7.93 (dd, J=5.3, 2.9Hz, 2H), 7.79 (dd, J=5.3, 3.0Hz, 2H).

[0146] Step B: Preparation of 3,5-dichloro-4-phthalimido-6-fluoropyridine methyl nitrile

[0147]

[0148] In a 100mL two-necked round-bottom flask, dimethyl sulfoxide (80mL) and potassium fluoride (0.905g, 15.6mmol) were added, and 30mL of dimethyl sulfoxide was distilled off under reduced pressure (40°C, 2.1mbar). Then, after the solution was cooled to room temperature, 3,5,6-trichloro-4-phthalimide-2-pyridinemethylnitrile (5g, 14.2mmol) was added, and the reaction was stirred for 24 hours. After the liquid chromatography monitored that the product accounted for 70% of the mixture, the reaction solution was poured into 1000mL of water, and the solid produced was collected by filtration and dried to obtain a white mixture of 3,5-dichloro-4-phthalimide-6-fluoropyridine-2-methylnitrile and 3-chloro-4-phthalimide-5,6-difluoropyridine-2-methylnitrile and part of the unreacted raw materials (4.72g, 14.08mmol).

[0149] Step C: Preparation of 3-(4-fluorophenyl)-1H-indole

[0150]

[0151] In a 50mL three-necked round-bottom flask, add ethanol (25mL) dried over 3A molecular sieves for 30 minutes, phenylhydrazine hydrochloride (1.05g, 7.24mmol), and trichlorocyanuric acid (0.13g, 0.72mmol). Add 4-fluorophenylacetaldehyde (1g, 7.24mmol) dropwise at room temperature with magnetic stirring. After the addition is completed, the temperature is raised to 75°C and the reaction is carried out for 2 hours. After the reaction is complete as monitored by TLC, the reaction solution is slowly poured into 50mL saturated sodium bicarbonate aqueous solution, and 30mL ethyl acetate is added under stirring. The organic phase is collected by stratification, and the aqueous phase is extracted 3 times with 20mL ethyl acetate. After the organic phases are combined and washed 3 times with 20mL brine, dried over anhydrous magnesium sulfate and concentrated, the crude product is purified by rapid column chromatography (eluent ethyl acetate: n-hexane = 1:100) to obtain 3-(4-fluorophenyl)-1H-indole (1.12g, 5.3mmol) with a yield of 73.2%.

[0152] 1 H NMR(500MHz,Chloroform-d)δ8.11(s,1H),7.79(d,J=8.0Hz,1H),7.55-7.50(m,2H),7.34(d,J=8. 1Hz,1H),7.21(d,J=2.5Hz,1H),7.20-7.14(m,1H),7.12(dd,J=8.1,8.0Hz,1H),7.08-7.02(m,2H).

[0153] Step D: Preparation of 3,5-dichloro-4-phthalimido-6-(3-(4-fluorophenyl)-1H-indol-1-yl)-pyridine-2-methylnitrile

[0154]

[0155] In a 50mL dark brown single-mouth round-bottom flask, NaH (60%, 0.2g, 5.04mmol) and 3-(4-fluorophenyl)-1H-indole (1g, 4.73mmol) were added in sequence and fully dissolved under magnetic stirring. After adding ultra-dry 1,4-dioxane (25mL) under argon protection, the reaction solution was heated to 70°C and stirred for 3 hours. Next, 3,5-dichloro-4-phthalimido-6-fluoropyridine-2-methylnitrile (70%, 1.51g, 3.15mmol) was added to the reaction solution and the temperature was raised to 100°C and the reaction was continued for 20 hours. After the reaction was completed by TLC monitoring, the reaction solution was slowly poured into 200 mL of water, filtered and dried to obtain 1.989 g of a solid containing 3,5-dichloro-4-phthalimido-6-(3-(4-fluorophenyl)-1H-indol-1-yl)pyridine-2-methylnitrile, with a mixture yield of 89.7%. The mixture was separated by rapid column chromatography (eluent ethyl acetate: n-hexane = 1:50) to obtain 3-chloro-4-phthalimido-5,6-di(3-(4-fluorophenyl)-1H-indol-1-yl)-pyridine-2-methylnitrile (1.312 g, 2.49 mmol), with a yield of 67%.

[0156] Step E: Preparation of 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)-pyridine-2-methylnitrile

[0157]

[0158] In a 50mL three-necked round-bottom flask, add ethanol (25mL) and 3,5-dichloro-4-phthalimido-6-(3-(4-fluorophenyl)-1H-indol-1-yl)pyridine-2-methylnitrile (1.3g, 2.47mmol), then add hydrazine hydrate (100%, 1.85g, 370mmol) dropwise under stirring at room temperature. After the addition is completed, continue to react at room temperature for 2 hours, slowly pour the reaction solution into 200mL of water, and filter to obtain a light yellow solid. The solid was added to 100 mL of 1N dilute hydrochloric acid, stirred thoroughly at room temperature and filtered to obtain a crude product. The crude product was purified by flash column chromatography (eluent ethyl acetate: n-hexane = 1:10) to obtain 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)picolinonitrile (0.93 g, 2.35 mmol) with a yield of 95%.

[0159] 1H NMR(500MHz,DMSO-d6)δ7.98(dd,J=7.1,1.6Hz,1H),7.95(dd,J=7.1,1.4Hz,1H),7.47(dd d,J=7.1,1.5,1.3Hz,1H),7.36(s,1H),7.31-7.25(m,3H),7.23(s,2H),7.22-7.16(m,2H).

[0160] Step F: Preparation of 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)-pyridine-2-carboxylic acid

[0161]

[0162] In a 25mL single-mouth round-bottom flask, add 10mL of water, 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)-pyridine-2-carbonitrile (0.4g, 1.01mmol) and potassium hydroxide (5g, 89.29mmol) in sequence. Heat to 100°C with stirring and heat under reflux overnight. After the reaction is complete as monitored by TLC, the reaction solution is slowly poured into 20mL of water, and the pH is adjusted to 2-3 with dilute hydrochloric acid. The white solid produced is collected by filtration and dried, which is 4-amino-3,5-dichloro-6-(3-(4-fluorophenyl)-1H-indol-1-yl)pyridine-2-carboxylic acid (0.381g, 0.92mmol), with a yield of 90.7%.

[0163] 1 H NMR (500MHz, DMSO-d6) δ13.80 (s, 1H), 7.95 (s, 1H), 7.91 (dd, J = 7.1, 1.5Hz, 1H), 7. 80-7.75(m,2H),7.38(dd,J=7.1,1.5Hz,1H),7.34-7.30(m,4H),7.29-7.23(m,2H).

[0164] The experimental scheme for synthesizing the compound represented by Formula I' is the same as that for the compound represented by Formula I, except that the reaction equation of step C is as follows:

[0165]

[0166] Step D, step E and step F are replaced accordingly.

[0167] The synthetic route of the compound shown in formula I'-6 is as follows Figure 2 As shown, the raw material ratios and reaction conditions are the same as the synthesis steps of the compound shown in formula I.

[0168] The experimental scheme for synthesizing the compound shown in formula II and the compound shown in formula III is as follows:

[0169] according to Figure 3 The synthesis of the compound represented by formula II and the compound represented by formula III is described in detail below by taking the synthesis of 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)-pyridine-2-carboxylic acid and 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-1-yl)-pyridine-2-carboxylic acid as examples.

[0170] Synthesis Example 2: Synthesis of derivatives 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-carboxylic acid and 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-1-yl)picolinic acid

[0171] Step A: Preparation of 4-chloro-1H-indazole

[0172]

[0173] In a 100mL three-necked round-bottom flask, tetrahydrofuran (50mL) and 2-chloro-6-fluorobenzaldehyde (5g, 31.53mmol) were added in sequence. After stirring and dissolving fully, hydrazine hydrate (3.16g, 63.07mmol) was slowly added dropwise at room temperature, and then the temperature was raised to 65°C for reaction for 2 hours. After TLC monitoring of the reaction was complete, the reaction solution was desolventized to obtain the intermediate compound 2-chloro-6-fluorobenzylidenehydrazine. In a 100mL three-necked round-bottom flask, hydrazine hydrate (50mL 100%), 2-chloro-6-fluorobenzylidenehydrazine (5g, 28.97mmol) and sodium bicarbonate (4.87g, 57.94mmol) were added in sequence. After stirring and dissolving, the temperature was raised to 100°C for reaction for 6 hours. After the reaction was completed as monitored by TLC, the reaction solution was slowly poured into an aqueous hydrochloric acid solution (200 mL 6N), and 30 mL of ethyl acetate was added under stirring. The organic phase was collected and separated, and the aqueous phase was extracted 3 times with 20 mL of ethyl acetate. The organic phases were combined and washed 3 times with 20 mL of brine, dried over anhydrous magnesium sulfate, and desolventized to obtain a light yellow solid 4-chloro-1H-indazole (3.14 g, 20.58 mmol) with a yield of 71%.

[0174] 1 H NMR (500MHz, DMSO-d6) δ13.46(s,1H),8.04(s,1H),7.58(d,J=8.2Hz,1H),7.35(d,J=7.2Hz,1H),7.29(dd,J=8.1,7.3Hz,1H).

[0175] Step B: Preparation of 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-methylnitrile and 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-2-yl)pyridine-2-methylnitrile

[0176]

[0177] In a 50mL three-necked round-bottom flask, add super dry dioxane (20mL), NaH (60%, 0.29g, 7.21mmol), 4-chloro-1H-indazole (1g, 6.55mmol) in sequence. After heating to 50°C and reacting for 3 hours under stirring, add 4-amino-3,5,6-trichloropyridine-2-methylnitrile (1.46g, 6.55mmol) and heat the reaction solution to 100°C for 24 hours. After the reaction is complete as monitored by TLC, the reaction solution is slowly poured into 200mL of water, filtered and dried to obtain a mixture of 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-methylnitrile and 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-2-yl)pyridine-2-methylnitrile (2.19g, 6.47mmol). After rapid column chromatography separation (eluent ethyl acetate: n-hexane = 1:10), a white solid 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-methylnitrile (0.75 g, 2.22 mmol) was obtained with a yield of 33.8%.

[0178] 1 H NMR (500MHz, DMSO-d6) δ8.51(s,1H),7.73(s,2H),7.65(d,J=8.4Hz,1H),7.51(dd,J=8.4,7.4Hz,1H),7.39(d,J=7.4Hz,1H).

[0179] 4-Amino-3,5-dichloro-6-(4-chloro-2H-indazol-2-yl)picolinonitrile (0.82 g, 2.42 mmol) was obtained as a pale yellow solid with a yield of 37.0%.

[0180] 1 H NMR (500MHz, DMSO-d6) δ8.91(s,1H),7.85(s,2H),7.72(d,J=8.8Hz,1H),7.37(dd,J=8.6,7.3Hz,1H),7.26(d,J=7.1Hz,1H).

[0181] Step C: Preparation of 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-carboxylic acid

[0182]

[0183] In a 25mL single-mouth round-bottom flask, add 10mL of 80% concentrated sulfuric acid and 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-methylnitrile (0.5g, 1.48mmol) in sequence. Heat to 100°C with stirring and heat under reflux for 3 hours. After TLC monitoring is complete, slowly pour the reaction solution into 20mL of water, filter and collect the white solid, and dry it to obtain 4-amino-3,5-dichloro-6-(4-chloro-1H-indazol-1-yl)pyridine-2-methyl acid (0.513g, 1.43mmol), with a yield of 97%.

[0184] 1 H NMR (500MHz, DMSO-d6) δ13.28(s,1H),8.50(s,1H),7.57(d,J=8.4Hz,1H),7.49(dd,J=7.5,7.3Hz,1H),7.38(d,J=7.3Hz,1H),7.38(s,2H).

[0185] Step D: Preparation of 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-2-yl)pyridine-2-carboxylic acid

[0186]

[0187] In a 25mL single-mouth round-bottom flask, add 10mL of 80% concentrated sulfuric acid and 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-2-yl)pyridine methyl nitrile (0.5g, 1.48mmol) in sequence, heat to 100°C with stirring, and heat under reflux for 3 hours. After the reaction is complete as monitored by TLC, the reaction solution is slowly poured into 20mL of water, and the yellow solid collected by filtration is dried to obtain 4-amino-3,5-dichloro-6-(4-chloro-2H-indazol-2-yl)pyridine-2-carboxylic acid (0.501g, 1.40mmol), with a yield of 95%.

[0188] 1 H NMR (500MHz, DMSO-d6) δ13.98(s,1H),8.93(s,1H),7.73(d,J=8.8Hz,1H),7.48(s,2H),7.36(dd,J=8.7,7.2Hz,1H),7.25(d,J=7.1Hz,1H).

[0189] The experimental scheme for synthesizing the compound represented by Formula IV and the compound represented by Formula V is as follows:

[0190] according to Figure 4The synthesis of the compound represented by Formula IV and the compound represented by Formula V is shown in the flow chart. The synthesis of 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)picolinic acid and 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)picolinic acid methyl ester is used as an example to describe the synthesis of the compound represented by Formula IV and the compound represented by Formula V in detail.

[0191] Synthesis Example 3. Synthesis of derivatives 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carboxylic acid and 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carboxylic acid methyl ester

[0192] Step A: Preparation of 3,5-dichloro-4-phthalimido-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-methylnitrile

[0193]

[0194] In a 50mL three-necked round-bottom flask, add super dry dioxane (25mL), NaH (60%, 0.173g, 7.21mmol) and 4-chloro-1H-pyrrolo[2,3-b]pyridine (1g, 6.55mmol) in sequence. After stirring and dissolving, heat to 50°C and react for 3 hours, add 3,5,6-trichloro-4-phthalimidopyridine-2-methylnitrile (2.31g, 6.55mmol) and heat to 100°C and react for 24 hours. The reaction solution was slowly poured into water (200mL), the solid was collected by filtration and dried to obtain 3,5-dichloro-4-phthalimido-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-methylnitrile (2.88g, 6.14mmol), with a yield of 93.8%.

[0195] 1 H NMR (500MHz, DMSO-d6)8.25(d,J=5.1Hz,1H), δ8.13(dd,J=5.3,3.0Hz,2H),8.09(dd,J =5.3,3.0Hz,2H),7.62(d,J=3.6Hz,1H),7.43(d,J=5.1Hz,1H),6.87(d,J=3.7Hz,1H).

[0196] Step C: Preparation of 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-methylnitrile

[0197]

[0198] In a 50mL three-necked round-bottom flask, add ethanol (25mL) and 3,5-dichloro-4-phthalimido-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-methylnitrile (2g, 4.27mmol), then add hydrazine hydrate (100%, 3.70g, 739.1mmol) dropwise under stirring at room temperature. After the addition, continue the reaction at room temperature for 2 hours, slowly pour the reaction solution into water (200mL), filter and collect the solid, and dry to obtain a yellow solid 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carbonitrile (1.39g, 4.11mmol), with a yield of 96.2%.

[0199] 1 H NMR (500MHz, DMSO-d6)8.24(d,J=5.2Hz,1H),7.63(d,J=3.6Hz,1H),7.42(d,J=5.1Hz,1H),7.36(s,2H),6.84(d,J=3.7Hz,1H).

[0200] Step D: Preparation of 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carboxylic acid

[0201]

[0202] In a 25 mL single-mouth round-bottom flask, water (10 mL), 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carbonitrile (0.8 g, 2.36 mmol) and potassium hydroxide (5 g, 89.29 mmol) were added in sequence, and the temperature was raised to 100°C and refluxed overnight under stirring. The reaction solution was then slowly poured into water (20 mL), and the pH was adjusted to 2-3 with dilute hydrochloric acid. The white solid was collected by filtration and dried to obtain 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)picolinic acid (0.816 g, 2.28 mmol), with a yield of 96.6%.

[0203] 1 H NMR (500MHz, DMSO-d6) δ13.91(s,1H),8.23(d,J=5.2Hz,1H),7.87(d,J=3.7Hz,1H),7.37(d,J=5.2Hz,1H),7.33(s,2H),6.80(d,J=3.7Hz,1H).

[0204] Step E: Preparation of methyl 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carboxylate

[0205]

[0206] In a 25mL three-necked round-bottom flask, methanol (10mL) and 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)pyridine-2-carboxylic acid (0.4g, 1.12mmol) were added, and after stirring and dissolving, thionyl chloride (0.27g, 2.24mol) was slowly added dropwise at below 0°C. After the addition was completed, the reaction solution was heated to 40°C and reacted for 2 hours. The reaction solution was then poured into 100mL of saturated sodium bicarbonate aqueous solution, and the collected white solid was filtered and dried to obtain 4-amino-3,5-dichloro-6-(4-chloro-1H-pyrrolo[2,3-b]pyridin-1-yl)picolinic acid methyl ester (0.404g, 1.09mmol), with a yield of 97.2%.

[0207] 1 H NMR (500MHz, DMSO-d6) δ8.22(d,J=5.2Hz,1H),7.86(d,J=3.7Hz,1H),7.41(s,2H),7.37(d,J=5.2Hz,1H),6.79(d,J=3.7Hz,1H),3.88(s,3H).

[0208] Typical compounds of formula (I) (II) (III) (IV) (V) of the present invention prepared by the preparation methods of the above embodiments using different raw materials are listed in Table 1, but they in no way limit the scope of the present invention.

[0209] Table 1

[0210]

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217] * indicates that the compound is actually one of the specific compounds in the compounds shown in Formula I'. For the convenience of writing, it is classified as the compound shown in Formula I. The structural formula of the compound corresponding to * is as follows:

[0218]

[0219] Application Example 1

[0220] The biological activities against weeds were tested using the 6-nitrogen-containing and ring-substituted picolinic acid and some of its formate ester compounds prepared in the synthesis examples of the present invention:

[0221] The following are examples of biological activity assays using the compounds of the present invention. It should be noted that the present invention is not limited to the following examples.

[0222] The herbicidal activity evaluation test was carried out according to the following method:

[0223] (1) Preliminary screening test for activity on Arabidopsis: Weigh a certain mass of the compound described in the synthetic example of the present invention and dissolve it in an appropriate amount of DMSO. When used, mix it with the culture medium (1 / 2MS Medium / Murashige & Skoog Medium (with vitamins, Sucrose, Agar) culture medium, Beijing Coolbo Technology Co., Ltd.) to prepare the required concentration for the determination. The test plants are Arabidopsis seeds, which are normal populations cultivated indoors; using the dish test method, Arabidopsis seeds are evenly sown on the culture medium mixed with compounds and containing only DMSO, with three parallels for each compound; after sowing, the culture dish is placed in a 4°C refrigerator for 48 hours, and then taken out and placed in an incubator. The incubator conditions are 16 hours of light, 8 hours of darkness, a constant temperature of 22°C, and a humidity of 70%. The culture is cultured for 7 days, and the test results are observed and recorded on the seventh day;

[0224] The commercial herbicide amikacin was provided by Beijing Yingtai Jiahe Biotechnology Co., Ltd.

[0225] Experimental statistics: The root development of Arabidopsis thaliana in each treatment was counted and the root growth inhibition rate was calculated.

[0226]

[0227] Table 2. Inhibitory activity on root growth of Arabidopsis thaliana

[0228]

[0229]

[0230]

[0231] As shown in Table 2, the compounds of the present invention have a significant inhibitory effect on the root of Arabidopsis thaliana seed germination, and some compounds are even better than the commercial herbicide amloprotiliac acid, which preliminarily shows that the compounds of the present invention have certain biological activity and have the potential to be further developed into herbicides.

[0232] (2) Evaluation of biological activity on several common weeds:

[0233] Compounds of the invention and the closest prior art known were used as comparative examples:

[0234] Table 3. Compounds of the present invention and control compounds

[0235]

[0236] Weigh each compound according to the dosage, dissolve it with DMSO to prepare a 1.0% stock solution, and then dilute it with 0.1% Tween-80 water to the required concentration for use. The DMSO aqueous solution without the drug is used as the blank control. The test plants are seeds of rapeseed, quinoa, ramie and barnyard grass, which are normal populations cultivated indoors; using the dish test method, various grass seeds are evenly sown on a culture dish mixed with compounds and 0.1% Tween-80 water, and the culture dish is covered with seedling paper of appropriate size. Three parallels are used for each compound; after sowing, the culture dish is placed in a 4°C refrigerator for 48 hours, and then taken out and placed in an incubator. The incubator conditions are 16 hours of light, 8 hours of darkness, a constant temperature of 22°C, and a humidity of 70%. It is cultured for 7 days, and the test results are observed and recorded on the seventh day;

[0237] Test statistics: Statistics on the root development of weeds in each treatment and calculation of root growth inhibition rate

[0238]

[0239] Table 4. Inhibitory activity on root growth of rapeseed, quinoa, velvetleaf and barnyard grass (activity at the 2-4 leaf stage before seedling)

[0240]

[0241]

[0242]

[0243]

[0244] As shown in Table 4, the compounds of the present invention have a significant inhibitory effect on the germination roots of various weed seeds, and some compounds are even better than the commercial herbicide amloprotiliac acid, which preliminarily shows that the compounds of the present invention have certain pre-emergence biological activity.

[0245] Weigh each compound according to the dosage, dissolve it in DMSO to prepare a 1.0% stock solution, and then dilute it with 0.1% Tween-80 water for use. Use a DMSO aqueous solution without the drug as a blank control. Spray the test object at the 2-4 leaf stage; apply the drug quantitatively (calculate the application amount according to the pot area, and dispense it in a 10ml small spray bottle after preparation, and spray 10ml of the drug on each pot of grass), let it stand indoors, and after the weed leaves absorb the drug solution, move it to the greenhouse for cultivation, and conduct routine management for trial harvesting; observe the growth of weeds and poisoning symptoms regularly after the drug is applied, and visually observe the weed control effect 14 days after the drug is applied (all dead: 100; stem atrophy and leaf death: 99-80; stem atrophy and partial leaf death: 79-60; stem normal but partial leaf death: 59-40; stem normal and partial leaf curling: 39-20; stem normal and normal leaves: 19-0).

[0246] Table 5. Control effect on rapeseed and quinoa

[0247]

[0248]

[0249]

[0250] As shown in Table 5, the compounds of the present invention have a certain weed control effect on dicotyledonous weeds and have the potential to be further studied and developed into herbicides.

[0251] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, can implement the present invention in a wider range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principle of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including departing from the disclosed scope in the application and the changes made with conventional techniques known in the art.

Claims

1. As shown in Formula I, Formula I ’ , a compound represented by formula II, formula III, formula IV or formula V: In Formula I, Formula I', Formula II, Formula III, Formula IV and Formula V, R is selected from any one of hydrogen, halogen, halogen-substituted or unsubstituted C1-C6 straight or branched alkyl, C1-C6 alkoxy, and amino; In formula I, R1 is selected from hydrogen, C1-C6 straight chain or branched alkyl, substituted or unsubstituted benzene ring, wherein, The substituents in the substituted benzene ring are one or more, and the substituents in the substituted benzene ring are independently selected from any one of halogen, C1-C6 straight chain or branched alkyl, halogen-substituted C1-C6 straight chain or branched alkyl, and C1-C6 alkoxy; Formula I ’ In the above formula, R1' is (CH2) n , n is any natural number from 1 to 4.

2. The compound according to claim 1, characterized in that: In Formula I, Formula I', Formula II, Formula III, Formula IV and Formula V, R is any one of hydrogen, halogen, methyl, trifluoromethyl, methoxy and amino; In Formula I, R1 is selected from hydrogen, C1-C3 straight chain or branched alkyl, substituted or unsubstituted benzene ring, wherein the substituent in the substituted benzene ring is para-substituted, and the substituent is selected from any one of halogen, C1-C3 straight chain or branched alkyl, C1-C3 straight chain or branched alkoxy; In formula Ⅰ', R1' is (CH2) n , n is any natural number between 3 and 4.

3. The method for preparing the compound according to claim 1 or 2, which is the following method A, method B or method C: Method A, wherein the compound is a compound of formula I or a compound of formula I', comprises the following steps: 1) Protecting the amino group of the compound represented by formula A1 with a phthaloyl group to obtain a compound represented by formula A2; 2) Fluorinating the compound represented by formula A2 to obtain a compound represented by formula A3; 3) When the target product is a compound of formula I, reacting the compound of formula A4 with the compound of formula A5 to obtain a compound of formula A6; In Formula A4, Formula A5 and Formula A6, R and R1 are defined as in Formula I; When the target product is a compound represented by formula Ⅰ', reacting the compound represented by formula A4' with the compound represented by formula A5 to obtain a compound represented by formula A6'; In formula A4' and formula A6', R and R1' are defined the same as in formula Ⅰ'; 4) When the target product is a compound of formula I, reacting the compound of formula A3 with the compound of formula A6 to obtain a compound of formula A7; When the target product is a compound represented by formula Ⅰ', the compound represented by formula A3 is reacted with the compound represented by formula A6' to obtain a compound represented by formula A7'; 5) When the target product is a compound of formula I, removing the phthaloyl protection of the compound of formula A7 to obtain a compound of formula A8; When the target product is a compound represented by Formula Ⅰ', the phthaloyl protection of the compound represented by Formula A7' is removed to obtain a compound represented by Formula A8'; 6) When the target product is a compound of formula I, hydrolyzing the compound of formula A8 to obtain a compound of formula I; When the target product is a compound represented by formula Ⅰ', the compound represented by formula A8' is hydrolyzed to obtain a compound represented by formula Ⅰ'; Method B, wherein the compound is a compound of formula II or a compound of formula III, comprises the following steps: 1) subjecting the compound represented by formula B1 to a nucleophilic substitution reaction with hydrazine hydrate to obtain a compound represented by formula B2; In Formula B1 and Formula B2, R is defined the same as Formula II or Formula III; 2) subjecting the compound represented by formula B2 to a nucleophilic substitution reaction with hydrazine hydrate and ring closure to obtain a compound represented by formula B3; 3) subjecting the compound represented by formula B3 to a nucleophilic substitution reaction with the compound represented by formula B4, and separating them after the reaction is complete to obtain a compound represented by formula B5 and a compound represented by formula B6; 4) hydrolyzing the compound represented by formula B5 and the compound represented by formula B6 respectively to obtain the compound represented by formula II and the compound represented by formula III; Method C, wherein the compound is a compound of formula IV or a compound of formula V, comprising the following steps: 1) protecting the compound represented by formula C1 by phthaloyl to obtain the compound represented by formula C2; 2) subjecting the compound represented by formula C2 to a nucleophilic substitution reaction with the compound represented by formula C3 to obtain a compound represented by formula C4; In Formula C3 and Formula C4, R is defined the same as Formula IV or Formula V; 3) removing the phthaloyl protection of the compound represented by formula C4 to obtain the compound represented by formula C5; 4) hydrolyzing the compound represented by formula C5 to obtain the compound represented by formula IV; 5) The compound represented by formula IV is subjected to methyl esterification reaction with methanol to obtain the compound represented by formula V.

4. The method according to claim 3, characterized in that: In the method A, the step of protecting the phthaloyl group in step 1) comprises: reacting the compound represented by formula A1 with phthaloyl chloride in an organic solvent under the action of a catalyst to obtain a compound represented by formula A2; The molar ratio of the compound represented by formula A1 to the phthaloyl chloride is 1:(1-2); The catalyst is at least one of 4-dimethylaminopyridine, triethylamine and diisopropylethylamine; The organic solvent is acetonitrile, dimethylformamide or dimethyl sulfoxide; The reaction temperature in step 1) is 20-100°C and the reaction time is 1-6h; The fluorination step in step 2) comprises: subjecting the compound represented by formula A2 to a fluorination reaction with potassium fluoride to obtain a compound represented by formula A3; The molar ratio of the compound represented by formula A2 to the potassium fluoride is 1:(1-1.5); The temperature of the fluorination reaction is 20 to 50°C and the time is 18 to 24 hours; In step 3), the reaction is carried out in the presence of cyanuric chloride; The molar ratio of the compound represented by formula A4 to the compound represented by formula A5 and cyanuric chloride is 1:(1-1.3):0.1; The molar ratio of the compound represented by formula A4' to the compound represented by formula A5 and cyanuric chloride is 1:(1-1.3):0.1; In step 3), the reaction temperature is 50-80°C and the reaction time is 2-4h; In step 4), the reaction is carried out in the presence of NaH; The molar ratio of the compound represented by formula A3, the compound represented by formula A6, and NaH is 1:(1.5-2):(1.6-2.1); The molar ratio of the compound represented by formula A3, the compound represented by formula A6', and NaH is 1:(1.5-2):(1.6-2.1); The reaction in step 4) is carried out under the protection of an inert gas; In step 4), the reaction is carried out in ultra-dry 1,4-dioxane; In step 4), the reaction temperature is 70-100° C. and the reaction time is 18-24 hours; The step of removing the phthaloyl protection in step 5) comprises: reacting the compound represented by formula A7 or the compound represented by formula A7' with hydrazine hydrate; The molar ratio of the compound represented by formula A7 or the compound represented by formula A7' to hydrazine hydrate is 1:(100-200); The reaction in step 5) is carried out in ethanol, propanol or tetrahydrofuran; In step 5), the reaction temperature is 20-40° C. and the reaction time is 1-3 h; In step 6), the hydrolysis is carried out under alkaline or acidic conditions; The alkaline condition is provided by KOH, the hydrolysis temperature is 80-110° C., and the time is 10-25 hours.

5. The method according to claim 3, characterized in that: In the method B, the molar ratio of the compound represented by formula B1 in step 1) to the hydrazine hydrate is 1:(1-2); The organic solvent for the reaction in step 1) is tetrahydrofuran, dioxane, or toluene; The reaction temperature in step 1) is 60-100°C and the reaction time is 2-4h; The reaction in step 2) is carried out in the presence of an alkaline salt, sodium bicarbonate, and the molar ratio of the compound represented by formula B2 to sodium bicarbonate is 1:(2-3); In step 2), the hydrazine hydrate is 100% hydrazine hydrate; The reaction temperature in step 2) is 100°C and the reaction time is 4 to 8 hours; In step 3), the molar ratio of the compound represented by formula B3, the compound represented by formula B4, and NaH is (1-1.5):1:(1.1-1.6); In step 3), the reaction is carried out in ultra-dry 1,4-dioxane; In step 3), the reaction temperature is 70-100° C. and the reaction time is 18-24 hours; The hydrolysis in step 4) is carried out under alkaline or acidic conditions; The acidic condition is provided by 80% concentrated sulfuric acid, the hydrolysis temperature is 80-110° C., and the time is 1-5 hours.

6. The method according to claim 3, characterized in that: In the method C, the step of protecting the phthaloyl group in step 1) comprises: reacting the compound represented by formula C1 with phthaloyl chloride in an organic solvent under the action of a catalyst to obtain a compound represented by formula C2; The molar ratio of the compound represented by formula C1 to the phthaloyl chloride is 1:(1-2); The catalyst is at least one of 4-dimethylaminopyridine, triethylamine and diisopropylethylamine; The organic solvent is acetonitrile, dimethylformamide or dimethyl sulfoxide; The reaction temperature in step 1) is 20-100°C and the reaction time is 1-6h; In step 2), the compound represented by formula C2 and the compound represented by formula C3 are reacted in a molar ratio of (1-1.5):1:(1.1-1.6); The reaction in step 2) is carried out in ultra-dry 1,4-dioxane; In step 2), the reaction temperature is 70-100° C. and the reaction time is 18-24 hours; The step of removing the phthaloyl protection in step 3) comprises: reacting the compound represented by formula C4 with hydrazine hydrate to obtain the compound represented by formula C5; The molar ratio of the compound represented by formula C4 to hydrazine hydrate is 1:(100-200); The reaction in step 3) is carried out in ethanol, propanol or tetrahydrofuran; In step 3), the reaction temperature is 20-40°C and the reaction time is 1-3h; The hydrolysis in step 4) is carried out under alkaline or acidic conditions; The alkaline condition is provided by KOH, the hydrolysis temperature is 80-110°C, and the time is 10-25h; The reaction in step 5) is carried out in the presence of thionyl chloride, and the molar ratio of the compound represented by formula IV to thionyl chloride is 1:(1.5-3); The ratio of the compound represented by formula IV to methanol is 1 mmol: (5-15) mL; In step 5), the reaction temperature is 40-60° C. and the reaction time is 1-2 h.

7. Use of the compound according to claim 1 or 2 in any of the following: R1) inhibit weed growth; R2) inhibit root development of weed seeds; R3) Preparation of herbicides.

8. The use according to claim 7, characterized in that: The weeds are dicotyledonous weeds and / or monocotyledonous weeds.

9. The use according to claim 8, characterized in that: The dicotyledonous weeds are any one of Arabidopsis thaliana, velvetleaf, quinoa, Amaranthus reflexus, Purslane, Plantain, Artemisia selengensis, Pigweed, Morning Glory and Taraxacum officinale; The monocotyledonous weeds are any one of wild oats, foxtail grass, barnyard grass and crabgrass.

10. A herbicide, the active ingredient of which is the compound according to claim 1 or 2.

Images