A natural naphthoquinone derivative, its preparation method and application

Abstract

This invention relates to the fields of compound synthesis technology and pesticide technology, specifically to natural naphthoquinone derivatives and their preparation methods and applications. The natural naphthoquinone derivatives are either natural naphthoquinone derivatives containing aryl carboxylic acids or natural naphthoquinone derivatives containing diphenyl ether units. Some of the natural naphthoquinone aryl carboxylic acid derivatives and natural naphthoquinone diphenyl ether derivatives of this invention exhibit 100% control efficacy against six weeds (barnyard grass, crabgrass, foxtail grass, velvetleaf, amaranth, purslane, etc.) at a dosage of 300 a.g. / ha. These compounds achieve good weed control effects at low dosages and have relatively good safety for crops such as corn, wheat, peanuts, soybeans, and cotton. They can be used as selective herbicides in agriculture. The compounds of this invention can be developed and used as potential PSII inhibitors and post-emergence herbicides for broadleaf weeds. The derivatives have simple structures and preparation processes, low production costs, and broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of compound pesticides, specifically relating to a natural naphthoquinone derivative and its preparation method and application, as well as natural naphthoquinone aryl carboxylic acid derivatives or natural naphthoquinone diphenyl ether derivatives and D1 protease herbicides. Background Technology

[0002] Weeds are a crucial component of farmland ecosystems, posing a significant threat to agricultural production alongside diseases and pests. Weeds compete with crops for sunlight, space, water, and nutrients, leading to reduced yields and lower crop quality. Furthermore, the widespread use of herbicides has caused environmental pollution, reduced soil fertility, and pesticide residues. The continued use of herbicides has also resulted in the emergence of resistant weeds, and the number of resistant varieties is increasing, seriously impacting sustainable agricultural development. Therefore, researching and developing new, green, efficient, low-toxicity, and broad-spectrum herbicides remains a major challenge in weed control.

[0003] Plastoquinone is an important carrier of electrons in photosynthetic system II (PSII) and a key node for maintaining normal photosynthesis. Traditional PSII inhibitors work by binding plastoquinone (Q... B PSII competitively binds to the D1 protein, thereby interrupting electron transport, disrupting photosynthesis, and ultimately leading to plant death. Based on their interaction with the binding cavity in the D1 protein, PSII-inhibiting herbicides are classified into two categories: urea / triazine and phenolic herbicides. These herbicides have advantages such as a broad weed control spectrum, readily available raw materials, and simple structures. However, they also have drawbacks such as high application concentrations and long pesticide residue times, which can cause environmental harm with long-term use. Natural naphthoquinone compounds possess superior bioactivity, are easily degradable, and are environmentally friendly, attracting increasing attention from medicinal chemists and pesticide chemists. Therefore, designing and synthesizing small-molecule herbicides with high crop safety based on natural naphthoquinone units is highly consistent with the current trend in new pesticide development.

[0004] In the prior art, patent application number CN202310474254.6 discloses a class of aminonaphthoquinone derivatives and their preparation and uses for fungicide, herbicide, and algaecide. However, this compound only has inhibitory activity against Amaranthus retroflexus and Amaranthus chinensis, and both are post-emergence activities. Although the disclosed compounds have some similarities to the compounds of this invention, the compounds represented by the general formula of this invention are significantly different from those in the prior art, have a more novel structure, and exhibit better herbicidal activity. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by proposing a natural naphthoquinone derivative, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A natural naphthoquinone derivative, with the general structural formula shown in formula (I):

[0008]

[0009] In formula (I):

[0010] R is X 1 and X 4 Each can be independently H or CH3, X 2 Selected from carbonyl or sulfonyl groups respectively, X 3 Selected from O or S respectively, n is 1–5;

[0011] R 1 The groups are selected from C1-C6 alkyl, C1-C6 haloalkyl, unsubstituted or substituted by 1-4 independently selected from the following groups, unsubstituted or substituted by 1-4 independently selected from the following groups, furan methylene, thiazole methylene, tetrahydrofuran methylene or pyridinium methylene, wherein the following groups are hydrogen, fluorine, chlorine, bromine, iodine, cyano, nitro, hydroxyl, trifluoromethyl, C1-C6 alkyl, C1-C6 alkoxy, haloC1-C6 alkyl or haloC1-C6 alkoxy;

[0012] R 2 R 3 R 4 R 5 R 6 Each of them independently consists of hydrogen, fluorine, chlorine, bromine, iodine, cyano, nitro, hydroxyl, trifluoromethyl, C1-C6 alkyl, C1-C6 alkoxy, halo-C1-C6 alkyl, or halo-C1-C6 alkoxy.

[0013] R 7 The groups are selected from hydrogen, fluorine, chlorine, bromine, iodine, cyano, nitro, hydroxyl, trifluoromethyl, methyl, C1-C6 haloalkyl, C3-C6 alkenyl, and C3-C6 alkynyl, respectively.

[0014] R 8 for

[0015] X 5 Selected from C or N, R respectively a 、Rb R c R d Each of them independently consists of hydrogen, fluorine, chlorine, bromine, iodine, cyano, nitro, hydroxyl, trifluoromethyl, C1-C6 alkyl, C1-C6 alkoxy, halo-C1-C6 alkyl, or halo-C1-C6 alkoxy.

[0016] Furthermore, the natural naphthoquinone derivative includes the following compounds:

[0017] Compound A1: methyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)acetate;

[0018] Compound A2: 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)ethyl acetate;

[0019] Compound A3: Methyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate;

[0020] Compound A4: Ethyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate;

[0021] Compound A5: 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)benzyl acetate;

[0022] Compound A6: 1,4-dioxo-1,4-dihydronaphth-2-ylbenzenesulfonate;

[0023] Compound A7: 1,4-dioxo-1,4-dihydronaphth-2-yl-4-methylbenzenesulfonate;

[0024] Compound A8: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chlorobenzenesulfonate;

[0025] Compound A9: 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzenesulfonate;

[0026] Compound A10: 1,4-dioxo-1,4-dihydronaphth-2-yl-4-nitrobenzenesulfonate;

[0027] Compound A11: 1,4-dioxo-1,4-dihydronaphth-2-ylbenzoate;

[0028] Compound A12: 1,4-dioxo-1,4-dihydronaphth-2-yl 4-methoxybenzoate;

[0029] Compound A13: 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzoate;

[0030] Compound A14: 1,4-dioxo-1,4-dihydronaphth-2-yl 3-(trifluoromethyl)benzoate;

[0031] Compound A15: 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloro-2-methoxybenzoate;

[0032] Compound A16: 1,4-dioxo-1,4-dihydronaphth-2-ylfuran-2-carboxylic acid ester;

[0033] Compound A17: 1,4-dioxo-1,4-dihydronaphthio-2-ylthiophene-2-carboxylic acid ester;

[0034] Compound A18: 1,4-dioxo-1,4-dihydronaphth-2-ylnicotinate;

[0035] Compound A19: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloronicotinate;

[0036] Compound A20: 1,4-dioxo-1,4-dihydronaphth-2-yl-6-chloropyridine carboxylate;

[0037] Compound A21: 1,4-dioxo-1,4-dihydronaphth-2-yl-3-chloroisonicotinate;

[0038] Compound A22: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-fluoronicotinate;

[0039] Compound A23: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(trifluoromethyl)nicotinate;

[0040] Compound A24: 1,4-dioxo-1,4-dihydronaphth-2-yl 2,4-dichloronicotinate;

[0041] Compound A25: 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloropyridine carboxylate;

[0042] Compound A26: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-6-(trifluoromethyl)nicotinate;

[0043] Compound A27: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-phenoxynicotinate;

[0044] Compound A28: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(o-tolyloxy)nicotinate;

[0045] Compound A29: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(m-tolyloxy)nicotinic acid ester;

[0046] Compound A30: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(p-tolyloxy)nicotinic acid ester;

[0047] Compound A31: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dimethylphenoxy)nicotinic acid ester;

[0048] Compound A32: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3,5-dimethylphenoxy)nicotinic acid ester;

[0049] Compound A33: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,6-dimethylphenoxy)nicotinic acid ester;

[0050] Compound A34: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-fluorophenoxy)nicotinate;

[0051] Compound A35: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-chlorophenoxy)nicotinate;

[0052] Compound A36: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-bromophenoxy)nicotinic acid ester;

[0053] Compound A37: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3-(trifluoromethyl)phenoxy)nicotinic acid ester;

[0054] Compound A38: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2-chloro-4-fluorophenoxy)nicotinate;

[0055] Compound A39: 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dichlorophenoxy)nicotinic acid ester;

[0056] Compound A40: 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzene ester;

[0057] Compound A41: 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-5-(2-chloro-4-(trifluoromethyl)phenoxy)benzoate;

[0058] Compound A42: 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-methylbenzoate;

[0059] Compound A43: 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid;

[0060] Compound A44: 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(3-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid;

[0061] Compound A45: 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(4-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid;

[0062] Compound A46: 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((3-chloro-5-fluoropyridin-2-yl)oxy)phenoxy)propionic acid.

[0063] Another object of the present invention is to provide a method for preparing the natural naphthoquinone derivative, which uses the natural product 2-hydroxy-1,4-naphthoquinone and aryl carboxylic acid as the main raw materials and synthesizes them by etherification, hydrolysis, substitution or esterification reactions, respectively.

[0064] The preparation route of the natural naphthoquinone derivative is any one of the following:

[0065] Route 1:

[0066]

[0067] Route 2:

[0068]

[0069] The method for preparing the natural naphthoquinone derivative includes the following steps:

[0070] (1) Preparation of phenoxynicotinic acid (intermediate 3a-3m):

[0071] Various phenols / hydroxypyridines, cesium carbonate, cuprous bromide, and dry N,N-dimethylformamide (DMF) solution were mixed and stirred, and reacted at room temperature for half an hour. Then, 2-chloronicotinic acid was added, and the reaction system was reacted at 140°C for 10 hours. After the reaction was complete, the mixture was cooled to room temperature and then poured into water. The pH of the aqueous solution was adjusted to 2-4 with hydrochloric acid. The mixture was filtered off to obtain the desired solid product, phenoxynicotinic acid, which is intermediate 3a-3m.

[0072] (3) Preparation of methyl phenoxybenzoate (intermediates 4a-4c):

[0073] Mixtures of various halobenzenes / halopyridines, potassium carbonate, potassium iodide, and methyl 5-hydroxypolysubstituted benzoate were stirred in DMF at 80–100 °C for 10 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and then ethyl acetate and water were added to the solution for extraction. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated, and subjected to column chromatography to obtain methyl phenoxybenzoate (intermediates 4a-4c).

[0074] (4) Preparation of phenoxybenzoic acid (intermediates 5a-5c):

[0075] Intermediates 4a-4c were dissolved in methanol, and then lithium hydroxide monohydrate was added to the solution. The reaction solution was heated to 60°C and the reaction was continued for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into ice. The pH of the aqueous solution was adjusted to 2-4 with hydrochloric acid while stirring, and a solid gradually precipitated out. The obtained solid was filtered and dried in a vacuum to obtain intermediates 5a-5c.

[0076] (5) Preparation of polysubstituted phenoxyphenol / polysubstituted pyridine-2-yloxyphenol (intermediates 6a-6d): Various commercially available halobenzenes / halopyridines, potassium carbonate and potassium iodide were dissolved in DMF and reacted at room temperature for half an hour. Then hydroquinone or resorcinol was added and the reaction solution was heated to 80–100 °C and the reaction was continued for 10 hours. After the reaction was completed, the solution was cooled to room temperature and then ethyl acetate and water were added to the solution for extraction. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated and column chromatography were performed to obtain polysubstituted phenoxyphenol / polysubstituted pyridine-2-yloxyphenol (intermediates 6a-6d).

[0077] (6) Preparation of polysubstituted phenoxyphenoxypropionate methyl ester / polysubstituted pyridin-2-yloxyphenoxypropionate methyl ester (intermediates 7a-7d):

[0078] Intermediates 6a-6d were dissolved in potassium carbonate and potassium iodide in DMF. After reacting at room temperature for half an hour, methyl 2-chloropropionate was added. The reaction solution was then heated to 80–100 °C and reacted for 10 hours. After the reaction was completed, the solution was cooled to room temperature, and then ethyl acetate and water were added to the solution for extraction. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated, and column chromatography was performed to obtain polysubstituted phenoxyphenoxypropionate / polysubstituted pyridin-2-yloxyphenoxypropionate (intermediates 7a-7d).

[0079] (7) Preparation of polysubstituted phenoxyphenoxypropionic acid / polysubstituted pyridin-2-yloxyphenoxypropionic acid (intermediates 8a-8d):

[0080] Intermediates 7a-7d were dissolved in methanol, and lithium hydroxide monohydrate was added to the solution. The reaction solution was heated to 60°C and reacted for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into ice. The pH of the aqueous solution was adjusted to 2-4 with hydrochloric acid while stirring, and a solid gradually precipitated out. The obtained solid was filtered and dried under vacuum to obtain the intermediate polysubstituted phenoxyphenoxypropionic acid / polysubstituted pyridin-2-yloxyphenoxypropionic acid (intermediates 8a-8d).

[0081] (8) Preparation of polysubstituted benzoyl chlorides (intermediates b1-b16):

[0082] Intermediate 2a-2p was dissolved in dichloromethane, and then oxalyl chloride was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain the intermediate polysubstituted benzoyl chloride (intermediate b1-b16).

[0083] (9) Preparation of phenoxynicotinic chloride (intermediate C1-C13):

[0084] Intermediate 3a-3m was dissolved in dichloromethane, and then oxalyl chloride was slowly added to the solution under stirring; then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours; after the reaction was completed, the reaction system was concentrated under reduced pressure to obtain intermediate phenoxynicotinic chloride (intermediate c1-c13); (10) Preparation of phenoxybenzoyl chloride (intermediate d1-d3):

[0085] Intermediates 5a-5c were dissolved in dichloromethane, and then oxalyl chloride was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain intermediate phenoxybenzoyl chloride (intermediates d1-d3).

[0086] (11) Preparation of polysubstituted phenoxyphenoxypropionyl chloride / polysubstituted pyridin-2-yloxyphenoxypropionyl chloride (intermediates e1-e4):

[0087] Intermediates 8a-8d were dissolved in dichloromethane, and then oxaloyl chloride was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain the intermediates polysubstituted phenoxyphenoxypropionyl chloride / polysubstituted pyridin-2-yloxyphenoxypropionyl chloride (intermediates e1-e4).

[0088] (12) Preparation of target compounds A1-A5:

[0089] 2-Hydroxy-1,4-naphthoquinone, potassium carbonate, and potassium iodide were mixed in DMF solution and reacted at room temperature for half an hour. Then, the intermediate ClCH2COOR was added. 1 / ClCH(CH3)COOR 1 (1a-1f) The reaction system was heated to 80°C. After the reaction was complete, the solution was cooled to room temperature. Then, ethyl acetate and water were added to the solution for extraction. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated, and then purified by column chromatography to obtain the target compounds A1-A5.

[0090] (13) Preparation of target compound A6-A46:

[0091] 2-Hydroxy-1,4-naphthoquinone was dissolved in dichloromethane, and then triethylamine was added to the solution with stirring. Intermediates a1-a5, b1-b16, c1-c13, d1-d3, or e1-e4 were then slowly added. The reaction was carried out at room temperature. After the reaction was complete, the reaction system was concentrated under reduced pressure, dissolved in dichloromethane, and extracted with water. The organic layer was separated, dried, concentrated under reduced pressure, and purified by column chromatography to obtain the target compounds A6-A46.

[0092] The intermediate ClCH2COOR 1 / ClCH(CH3)COOR 1 (1a-1f), intermediate polysubstituted aryl carboxylic acids (2a-2u), and intermediate polysubstituted aryl carboxylic acids (a1-a5) are all commercially available products.

[0093] In step (2), the ratio of phenol / hydroxypyridine: cesium carbonate: cuprous bromide of each type is 1:1.3:1.3:0.3;

[0094] In step (2), the amount of DMF is controlled by adding 1 mL of DMF per millimol of 2-chloronicotinic acid.

[0095] In step (3), the ratio of halobenzene / halopyridine: methyl 5-hydroxypolysubstituted benzoate: potassium carbonate: potassium iodide is 1:1.3:1.5:0.1;

[0096] In step (3), the amount of DMF is controlled by adding 1 mL of DMF per millimole of halobenzene / halopyridine.

[0097] In step (4), intermediate 4a-4c: lithium hydroxide monohydrate = 1:0.5;

[0098] In step (4), the amount of hydrochloric acid used is controlled by adding 1 mL of hydrochloric acid per millimole of intermediate 4a-4c.

[0099] In step (4), the amount of methanol used is controlled by adding 1 mL of methanol per millimole of intermediate 4a-4c.

[0100] In step (5), the ratio of hydroquinone or resorcinol: halobenzene / halopyridine: potassium carbonate: potassium iodide = 0.5:1:1.5:0.1;

[0101] In step (5), the amount of DMF is controlled by adding 1 mL of DMF per millimol of hydroquinone or resorcinol.

[0102] In step (6), the ratio of intermediate 6a-6d: methyl 2-chloropropionate: potassium carbonate: potassium iodide = 1:1.3:1.5:0.1;

[0103] In step (6), the amount of DMF is controlled by adding 1 mL of DMF per millimole of intermediate 6a-6d;

[0104] In step (7), the amount of hydrochloric acid used is controlled by adding 1 mL of hydrochloric acid per millimole of intermediate 3a-3f;

[0105] In step (7), intermediates 7a-7d: lithium hydroxide monohydrate = 1:0.5;

[0106] In step (7), the amount of methanol used is controlled by adding 1 mL of methanol per millimol of intermediate 7a-7d.

[0107] In step (8), intermediate 2a-2p: oxaloyl chloride = 1:2;

[0108] In step (8), the amount of dichloromethane used is controlled by adding 1 mL of dichloromethane per millimole of intermediate 2a-2p.

[0109] In step (8), the amount of DMF is controlled by adding 2 drops of DMF per millimole of intermediate 2a-2p;

[0110] In step (9), intermediate 3a-3m: oxalyl chloride = 1:2;

[0111] In step (9), the amount of dichloromethane used is controlled by adding 1 mL of dichloromethane per millimole of intermediate 3a-3m.

[0112] In step (9), the amount of DMF is controlled by adding 2 drops of DMF per millimole of intermediate 3a-3m;

[0113] In step (10), intermediates 5a-5c: oxalyl chloride = 1:2;

[0114] In step (10), the amount of dichloromethane used is controlled by adding 1 mL of dichloromethane per millimole of intermediate 5a-5c.

[0115] In step (10), the amount of DMF is controlled by adding 2 drops of DMF per millimole of intermediate 5a-5c;

[0116] In step (11), intermediates 8a-8d: oxalyl chloride = 1:2;

[0117] In step (11), the amount of dichloromethane used is controlled by adding 1 mL of dichloromethane per millimole of intermediate 5a-5c.

[0118] In step (11), the amount of DMF is controlled by adding 2 drops of DMF per millimole of intermediate 5a-5c;

[0119] In step (12), the amounts of 2-hydroxy-1,4-naphthoquinone, intermediate 1a-1f, potassium carbonate, and potassium iodide are in the following molar ratio: 2-hydroxy-1,4-naphthoquinone: intermediate 1a-1f: potassium carbonate: potassium iodide = 1:1.3:1.5:0.1;

[0120] In step (12), the amount of DMF is controlled by adding 1 mL of DMF per millimole of intermediate 1a-1f;

[0121] In step (13), the amounts of 2-hydroxy-1,4-naphthoquinone, intermediates a1-a5, b1-b16, c1-c13, d1-d3 or e1-e4 and triethylamine are in the following molar ratio: 2-hydroxy-1,4-naphthoquinone: intermediate 1a-1f: triethylamine = 1:1.2:1.2;

[0122] In step (13), the amount of dichloromethane is controlled by adding 1 mL of dichloromethane per millimole of intermediates a1-a5, b1-b16, c1-c13, d1-d3 or e1-e4.

[0123] Another object of the present invention is the use of the natural naphthoquinone derivative in the preparation of herbicides and weed growth enzyme inhibitors.

[0124] Specifically, the weeds are barnyard grass, barnyard grass, velvetleaf, amaranth retroflexus, lambsquarters, ryegrass, purslane, bermudagrass, rapeseed, speedwell, amaranth, black nightshade, bitter lettuce, dandelion, sage, clover, chickweed, goosegrass, goosegrass, and foxtail grass.

[0125] Beneficial effects:

[0126] This invention is based on the 2-hydroxy-1,4-naphthoquinone structure and introduces aryl carboxylic acids, diphenyl ethers, and other herbicidal active pharmacophores, thus creating a small molecule of natural naphthoquinone herbicide containing aryl carboxylic acids or diphenyl ethers with relatively stable physicochemical properties and excellent drug-like properties. This type of derivative has a certain inhibitory effect on barnyard grass, crabgrass, foxtail grass, velvetleaf, amaranth, and purslane both before and after emergence, and shows relatively good crop safety for broadleaf crops.

[0127] Pre-emergence herbicidal activity tests showed that all target compounds exhibited significantly better inhibitory effects on broadleaf weeds than on grass weeds, regardless of whether the concentration was 100 μg / mL or 10 μg / mL. At a concentration of 100 μg / mL, compounds A27, A33, A38, A40, and A41 demonstrated excellent pre-emergence inhibitory effects on *Amaranthus retroflexus* and *Portulaca oleracea*, with weeds showing virtually no growth and inhibition rates reaching 100%, superior to the positive control atrazine and comparable to the positive control trifluralin. Post-emergence herbicidal activity tests showed that most natural naphthoquinone compounds, at a dosage of 300 g ai ha, exhibited good herbicidal activity against *Abutilon theophrasti*, *Amaranthus retroflexus*, and *Portulaca oleracea*, with inhibition rates all exceeding 100%. Compounds A43 and A44 exhibit excellent herbicidal activity against barnyard grass, crabgrass, and foxtail grass, with inhibition rates exceeding 80% at 75-150 g ai / ha. Some compounds showed herbicidal activity comparable to the positive control trifluralin, causing the weeds to wither and their growth to be inhibited.

[0128] The natural naphthoquinone derivatives containing aryl carboxylic acids or diphenyl ethers of the present invention have simple structures, simple preparation processes, low production costs, high yields, low toxicity, easy degradation, good environmental compatibility, high safety in use, and the preparation process is non-toxic and harmless. Attached Figure Description

[0129] Figure 1 The preparation route diagram for natural naphthoquinone derivatives A1-A5;

[0130] Figure 2 This is a route diagram for the preparation of natural naphthoquinone derivatives A6-A46. Detailed Implementation

[0131] The specific embodiments of the present invention will be described in further detail below, but the present invention is not limited to these embodiments. Any improvements or substitutions based on the basic spirit of these embodiments shall still fall within the scope of protection claimed by the claims of the present invention.

[0132] The preparation routes of the natural naphthoquinone derivatives provided in Examples 1-46 are as follows:

[0133] Route 1:

[0134]

[0135] Route 2:

[0136]

[0137]

[0138] Example 1: Preparation method of methyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)acetate (i.e., compound A1):

[0139] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol), K₂CO₃ (357.11 mg, 2.58 mmol), and KI (28.6 mg, 172.26 μmol) were dissolved in 30 mL of DMF. After reacting at room temperature for half an hour, methyl 2-chloroacetate (243.02 mg, 2.24 mmol) was added to the reaction system, and the solution was heated to 80-100 °C. The reaction was continued for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and ethyl acetate (100 mL) and H₂O (100 mL) were added to the solution. The organic layer was separated, washed with H₂O (100 mL) and saturated NH₄Cl solution (100 mL), dried over anhydrous Na₂SO₄, concentrated under reduced pressure, and column chromatography was performed to obtain 0.24 g of methyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)acetate, with a yield of 56.39%.

[0140] Example 2: Preparation method of ethyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)ethyl acetate (i.e., compound A2):

[0141] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol), K₂CO₃ (357.11 mg, 2.58 mmol), and KI (28.6 mg, 172.26 μmol) were dissolved in 30 mL of DMF. After reacting at room temperature for half an hour, ethyl 2-chloroacetate (274.43 mg, 2.24 mmol) was added to the reaction system, and the solution was heated to 80-100 °C. The reaction was continued for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and ethyl acetate (100 mL) and H₂O (100 mL) were added to the solution. The organic layer was separated, washed with H₂O (100 mL) and saturated NH₄Cl solution (100 mL), dried over anhydrous Na₂SO₄, concentrated under reduced pressure, and column chromatography was performed to obtain 0.25 g of ethyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)acetate, with a yield of 55.76%.

[0142] Example 3: Preparation method of methyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate (i.e., compound A3):

[0143] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol), K₂CO₃ (357.11 mg, 2.58 mmol), and KI (28.6 mg, 172.26 μmol) were dissolved in 30 mL of DMF. After reacting at room temperature for half an hour, methyl 2-chloropropionate (274.43 mg, 2.24 mmol) was added to the reaction system, and the solution was heated to 80-100 °C. The reaction was then continued for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and ethyl acetate (100 mL) and H₂O (100 mL) were added to the solution. The organic layer was separated, washed with H2O (100 mL) and saturated NH4Cl solution (100 mL), dried over anhydrous Na2SO4, concentrated under reduced pressure, and subjected to column chromatography to obtain 0.26 g of methyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate, with a yield of 57.32%.

[0144] Example 4: Preparation method of ethyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate (i.e., compound A4):

[0145] Dissolve 2-hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol), K₂CO₃ (357.11 mg, 2.58 mmol), and KI (28.6 mg, 172.26 μmol) in 30 mL of DMF. After reacting at room temperature for half an hour, ethyl 2-chloropropionate (305.84 mg, 2.24 mmol) was added to the reaction system, and the solution was heated to 80-100 °C. The reaction was then continued for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and ethyl acetate (100 mL) and H₂O (100 mL) were added to the solution. The organic layer was separated, washed with H2O (100 mL) and saturated NH4Cl solution (100 mL), dried with anhydrous Na2SO4, concentrated under reduced pressure, and column chromatography was performed to obtain 0.26 g of ethyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate, with a yield of 55.66%.

[0146] Example 5: Preparation method of 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)benzyl acetate (i.e., compound A5):

[0147] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol), K₂CO₃ (357.11 mg, 2.58 mmol), and KI (28.6 mg, 172.26 μmol) were dissolved in 30 mL of DMF. After reacting at room temperature for half an hour, benzyl 2-chloroacetate (413.43 mg, 2.24 mmol) was added to the reaction system, and the solution was heated to 80-100 °C. The reaction was then continued for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and ethyl acetate (100 mL) and H₂O (100 mL) were added to the solution. The organic layer was separated, washed with H2O (100 mL) and saturated NH4Cl solution (100 mL), dried over anhydrous Na2SO4, concentrated under reduced pressure, and subjected to column chromatography to obtain 0.29 g of ethyl 2-((1,4-dioxo-1,4-dihydronaphth-2-yl)oxy)propionate, with a yield of 52.59%.

[0148] Example 6: Preparation method of 1,4-dioxo-1,4-dihydronaphth-2-ylbenzenesulfonate (i.e., compound A6):

[0149] 2-Hydroxy-1,4-naphthoquinone (250.0 mg, 1.44 mmol) and Et3N (174.32 mg, 1.72 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, benzenesulfonyl chloride (304.24 mg, 1.72 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.22 g of 1,4-dioxo-1,4-dihydronaphthyl-2-ylbenzenesulfonate, with a yield of 48.32%.

[0150] Example 7: Preparation method of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-methylbenzenesulfonate (i.e., compound A7):

[0151] 2-Hydroxy-1,4-naphthoquinone (250.0 mg, 1.44 mmol) and Et3N (174.32 mg, 1.72 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 4-methylbenzenesulfonyl chloride (328.40 mg, 1.72 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.22 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-methylbenzenesulfonate, with a yield of 47.53%.

[0152] Example 8: Preparation method of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-chlorobenzenesulfonate (i.e., compound A8):

[0153] 2-Hydroxy-1,4-naphthoquinone (250.0 mg, 1.44 mmol) and Et3N (174.32 mg, 1.72 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-chlorobenzenesulfonyl chloride (363.57 mg, 1.72 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.21 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-chlorobenzenesulfonate, with a yield of 41.95%.

[0154] Example 9: Preparation method of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzenesulfonate (i.e., compound A9):

[0155] 2-Hydroxy-1,4-naphthoquinone (250.0 mg, 1.44 mmol) and Et3N (174.32 mg, 1.72 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 4-fluorobenzenesulfonyl chloride (335.23 mg, 1.72 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.22 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzenesulfonate, with a yield of 46.12%.

[0156] Example 10: Preparation method of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-nitrobenzenesulfonate (i.e., compound A10):

[0157] 2-Hydroxy-1,4-naphthoquinone (250.0 mg, 1.44 mmol) and Et3N (174.32 mg, 1.72 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 4-nitrobenzenesulfonyl chloride (381.75 mg, 1.72 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.24 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-nitrobenzenesulfonate, with a yield of 46.34%.

[0158] Example 11: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-ylbenzoate (i.e., compound A11), comprising the following steps:

[0159] Step (1) Preparation of benzoyl chloride intermediate (b1):

[0160] Intermediate 2a (400.0 mg, 4.09 mmol) was dissolved in 30 mL of CH2Cl2, and then oxalyl chloride (1.04 g, 8.19 mmol) was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain 0.55 g of benzoyl chloride (intermediate b1), with a yield of 94.87%.

[0161] Step (2) Preparation of 1,4-dioxo-1,4-dihydronaphthalene-2-ylbenzoate:

[0162] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, benzoyl chloride (290.57 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.28 g of 1,4-dioxo-1,4-dihydronaphthyl-2-ylbenzoate, with a yield of 57.34%.

[0163] Example 12: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 4-methoxybenzoate (i.e., compound A12), comprising the following steps:

[0164] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2b;

[0165] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-methoxybenzoate:

[0166] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 4-methoxybenzoyl chloride (352.63 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.27 g of 1,4-dioxo-1,4-dihydronaphthyl-2-ylbenzoate, with a yield of 50.28%.

[0167] Example 13: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzoate (i.e., compound A13), comprising the following steps:

[0168] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2c;

[0169] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzoate:

[0170] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 4-fluoroformyl chloride (327.76 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.25 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzoate, with a yield of 48.20%.

[0171] Example 14: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 3-(trifluoromethyl)benzoate (i.e., compound A14), comprising the following steps:

[0172] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2d;

[0173] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 4-fluorobenzoate:

[0174] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 3-(trifluoromethyl)benzoyl chloride (431.13 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.27 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 3-(trifluoromethyl)benzoate, with a yield of 45.27%.

[0175] Example 15: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloro-2-methoxybenzoate (i.e., compound A15), comprising the following steps:

[0176] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2e;

[0177] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloro-2-methoxybenzoate:

[0178] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 3,6-dichloro-2-methoxybenzoyl chloride (495.03 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.20 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloro-2-methoxybenzoate, with a yield of 32.32%.

[0179] Example 16: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-ylfuran-2-carboxylic acid ester (i.e., compound A16), comprising the following steps:

[0180] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2f;

[0181] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-ylfuran-2-carboxylic acid ester:

[0182] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, furan-2-carbonyl chloride (269.82 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.25 g of 1,4-dioxo-1,4-dihydronaphthyl-2-ylfuran-2-carboxylic acid ester, with a yield of 54.32%.

[0183] Example 17: A method for preparing 1,4-dioxo-1,4-dihydronaphthio-2-ylthiophene-2-carboxylic acid ester (i.e., compound A17), comprising the following steps:

[0184] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2g;

[0185] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphthio-2-ylthiophene-2-carboxylic acid ester:

[0186] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of thiophene-2-carbonyl chloride (303.02 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.28 g of 1,4-dioxo-1,4-dihydronaphthio-2-ylthiophene-2-carboxylic acid ester, with a yield of 56.35%.

[0187] Example 18: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-ylnicotinic acid ester (i.e., compound A18), comprising the following steps:

[0188] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2h;

[0189] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphthalene-2-ylnicotinate:

[0190] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, nicotinyl chloride (292.61 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.25 g of 1,4-dioxo-1,4-dihydronaphth-2-ylnicotinic acid ester, with a yield of 52.19%.

[0191] Example 19: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloronicotinate (i.e., compound A19) includes the following steps:

[0192] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2i;

[0193] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloronicotinate:

[0194] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-chloronicotinyl chloride (363.81 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.29 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-chloronicotinate, with a yield of 53.85%.

[0195] Example 20: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 6-chloropyridine carboxylate (i.e., compound A20), comprising the following steps:

[0196] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2j;

[0197] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 6-chloropyridine carboxylate:

[0198] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 6-chloropyridinyl chloride (363.81 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.27 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 6-chloropyridine carboxylate, with a yield of 49.78%.

[0199] Example 21: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 3-chloroisonicotinic acid ester (i.e., compound A21), comprising the following steps:

[0200] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2k;

[0201] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 3-chloroisonicotinate:

[0202] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 3-chloroisonicotinyl chloride (363.81 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.22 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 3-chloroisonicotinic acid ester, with a yield of 41.27%.

[0203] Example 22: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-fluoronicotinic acid ester (i.e., compound A22), comprising the following steps:

[0204] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2l;

[0205] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-fluoronicotinic acid ester:

[0206] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-fluoronicotinic acid chloride (329.80 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.17 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-fluoronicotinic acid ester, with a yield of 30.47%.

[0207] Example 23: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(trifluoromethyl)nicotinic acid ester (i.e., compound A23), comprising the following steps:

[0208] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2m;

[0209] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(trifluoromethyl)nicotinate:

[0210] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(trifluoromethyl)nicotinyl chloride (433.17 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.22 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(trifluoromethyl)nicotinic acid ester, with a yield of 36.78%.

[0211] Example 24: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2,4-dichloronicotinate (i.e., compound A24), comprising the following steps:

[0212] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2n;

[0213] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2,4-dichloronicotinate:

[0214] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2,4-dichloronicotinyl chloride (435.0 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.34 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2,4-dichloronicotinate, with a yield of 56.36%.

[0215] Example 25: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloropyridine carboxylate (i.e., compound A25), comprising the following steps:

[0216] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2o;

[0217] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloropyridine carboxylate:

[0218] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 3,6-dichloropyridinyl chloride (363.81 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.19 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 3,6-dichloropyridine carboxylate, with a yield of 30.85%.

[0219] Example 26: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-6-(trifluoromethyl)nicotinate (i.e., compound A26), comprising the following steps:

[0220] Step (1): Referring to step (1) of Example 11, intermediate 2a is replaced with intermediate 2p;

[0221] Step (2): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-6-(trifluoromethyl)nicotinate:

[0222] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 3,6-dichloropyridinyl chloride (363.81 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.37 g of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-6-(trifluoromethyl)nicotinic acid ester, with a yield of 56.27%.

[0223] Example 27: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-phenoxynicotinic acid ester (i.e., compound A27), comprising the following steps:

[0224] Step (1): Preparation of 2-phenoxynicotinic acid intermediate (3a):

[0225] Phenol (621.24 mg, 6.60 mmol), Cs₂CO₃ (2.15 g, 6.60 mmol), and CuBr (218.52 mg, 1.52 mmol) were dissolved in 40 mL of DMF and reacted at room temperature for half an hour. Then, 2-chloronicotinic acid (800.0 mg, 5.08 mmol) was added, and the reaction system was reacted at 140 °C for 10 hours. After the reaction was complete, the mixture was cooled to room temperature and then poured into an appropriate amount of water. The pH of the aqueous solution was adjusted to 2-4 with hydrochloric acid, and the mixture was filtered off to obtain 0.86 g of the desired solid product 2-phenoxynicotinic acid (intermediate 3a), with a yield of 78.90%.

[0226] Step (2): Preparation of 2-phenoxynicotinic acid chloride intermediate (c1):

[0227] Intermediate 3a (500.0 mg, 2.32 mmol) was dissolved in 30 mL of CH2Cl2, and then oxalyl chloride (1.04 g, 4.65 mmol) was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain 0.52 g of benzoyl chloride (intermediate c1), with a yield of 95.79%.

[0228] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-phenoxynicotinic acid ester:

[0229] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 2-phenoxynicotinyl chloride (482.99 mg, 2.07 mmol) in 10 mL of CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.36 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-phenoxynicotinic acid ester, with a yield of 56.75%.

[0230] Example 28: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(o-tolyloxy)nicotinic acid ester (i.e., compound A28), comprising the following steps:

[0231] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3b;

[0232] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c2;

[0233] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(o-tolyloxy)nicotinic acid ester:

[0234] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(o-tolyloxy)nicotinyl chloride (511.98 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.47 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(o-tolyloxy)nicotinic acid ester, with a yield of 70.80%.

[0235] Example 29: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(m-tolyloxy)nicotinic acid ester (i.e., compound A29), comprising the following steps:

[0236] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3c;

[0237] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c3;

[0238] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(m-tolyloxy)nicotinic acid ester:

[0239] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(m-tolyloxy)nicotinyl chloride (511.98 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.44 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(m-tolyloxy)nicotinic acid ester, with a yield of 65.98%.

[0240] Example 30: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-(p-toluoxy)nicotinic acid ester (i.e., compound A30), comprising the following steps:

[0241] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3d;

[0242] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c4;

[0243] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(p-toluoxy)nicotinic acid ester:

[0244] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(o-tolyloxy)nicotinyl chloride (511.98 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.46 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(p-tolyloxy)nicotinic acid ester, with a yield of 68.99%.

[0245] Example 31: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dimethylphenoxy)nicotinic acid ester (i.e., compound A31), comprising the following steps:

[0246] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3e;

[0247] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c5;

[0248] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dimethylphenoxy)nicotinic acid ester:

[0249] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(2,4-dimethylphenoxy)nicotinyl chloride (540.98 mg, 2.07 mmol) CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.40 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dimethylphenoxy)nicotinic acid ester, with a yield of 58.13%.

[0250] Example 32: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3,5-dimethylphenoxy)nicotinic acid ester (i.e., compound A32), comprising the following steps:

[0251] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3f;

[0252] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c6;

[0253] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3,5-dimethylphenoxy)nicotinic acid ester:

[0254] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(3,5-dimethylphenoxy)nicotinyl chloride (540.98 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.38 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3,5-dimethylphenoxy)nicotinic acid ester, with a yield of 54.94%.

[0255] Example 33: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,6-dimethylphenoxy)nicotinic acid ester (i.e., compound A33), comprising the following steps:

[0256] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3g;

[0257] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c7;

[0258] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,6-dimethylphenoxy)nicotinic acid ester:

[0259] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(2,6-dimethylphenoxy)nicotinyl chloride (540.98 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.39 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,6-dimethylphenoxy)nicotinic acid ester, with a yield of 56.98%.

[0260] Example 34: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-fluorophenoxy)nicotinic acid ester (i.e., compound A34), comprising the following steps:

[0261] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3h;

[0262] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c8;

[0263] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-fluorophenoxy)nicotinic acid ester:

[0264] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(4-fluorophenoxy)nicotinyl chloride (520.17 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.44 g of 1,4-dioxo-1,4-dihydronaphthyl-2-yl 2-(4-fluorophenoxy)nicotinic acid ester, with a yield of 64.85%.

[0265] Example 35: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-chlorophenoxy)nicotinic acid ester (i.e., compound A35), comprising the following steps:

[0266] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3i;

[0267] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c9;

[0268] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-chlorophenoxy)nicotinic acid ester:

[0269] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(4-chlorophenoxy)nicotinyl chloride (554.18 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.48 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-chlorophenoxy)nicotinic acid ester, with a yield of 68.95%.

[0270] Example 36: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-bromophenoxy)nicotinic acid ester (i.e., compound A36), comprising the following steps:

[0271] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3j;

[0272] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c10;

[0273] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(4-bromophenoxy)nicotinic acid ester:

[0274] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(4-bromophenoxy)nicotinyl chloride (646.07 mg, 2.07 mmol) in CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.47 g of 1,4-dioxo-1,4-dihydronaphthyl-2-yl 2-(4-bromophenoxy)nicotinic acid ester, with a yield of 60.60%.

[0275] Example 37: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3-(trifluoromethyl)phenoxy)nicotinic acid ester (i.e., compound A37), comprising the following steps:

[0276] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3k;

[0277] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c11;

[0278] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3-(trifluoromethyl)phenoxy)nicotinic acid ester:

[0279] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(3-(trifluoromethyl)phenoxy)nicotinic acid chloride (623.55 mg, 2.07 mmol) CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.44 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(3-(trifluoromethyl)phenoxy)nicotinic acid ester, with a yield of 58.53%.

[0280] Example 38: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2-chloro-4-fluorophenoxy)nicotinic acid ester (i.e., compound A38), comprising the following steps:

[0281] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3l;

[0282] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c12;

[0283] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2-chloro-4-fluorophenoxy)nicotinic acid ester:

[0284] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(2-chloro-4-fluorophenoxy)nicotinyl chloride (591.37 mg, 2.07 mmol) CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.42 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2-chloro-4-fluorophenoxy)nicotinic acid ester, with a yield of 56.99%.

[0285] Example 39: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dichlorophenoxy)nicotinic acid ester (i.e., compound A39), comprising the following steps:

[0286] Step (1): Referring to step (1) of Example 27, intermediate 3a is replaced with intermediate 3m;

[0287] Step (2): Referring to step (2) of Example 27, intermediate c1 is replaced with intermediate c13;

[0288] Step (3): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dichlorophenoxy)nicotinic acid ester:

[0289] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(2,4-dichlorophenoxy)nicotinyl chloride (625.38 mg, 2.07 mmol) CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.42 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 2-(2,4-dichlorophenoxy)nicotinic acid ester, with a yield of 54.86%.

[0290] Example 40: Preparation method of 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate (i.e., compound A40), including the following steps:

[0291] Step (1): Preparation of methyl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate (4a):

[0292] Methyl 5-hydroxy-2-nitrobenzene (1.19 g, 6.05 mmol), K₂CO₃ (964.24 mg, 6.98 mmol), and KI (77.21 mg, 465.12 μmol) were dissolved in 40 mL of DMF and reacted at room temperature for half an hour. Then, 1,2-dichloro-4-(trifluoromethyl)benzene (1.0 g, 4.65 mmol) was added and the mixture was stirred at 80–100 °C for 10 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and then ethyl acetate and water were added to the solution for extraction. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated, and column chromatography was performed to obtain 1.5 g of methyl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzene (intermediate 4a), with a yield of 85.71%.

[0293] Step (2): Preparation of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoic acid (5a):

[0294] Intermediate 4a (1.50 g, 3.99 mmol) was dissolved in 40 mL of CH3OH, and then LiOH·H2O (83.77 mg, 2.0 mmol) was added. The reaction solution was heated to 60 °C and reacted for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into ice. The pH of the aqueous solution was adjusted to 2-4 with hydrochloric acid while stirring, and a solid gradually precipitated out. The obtained solid was filtered and dried under vacuum to obtain 1.2 g of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoic acid (intermediate 5a), with a yield of 83.3%.

[0295] Step (3): Preparation of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoyl chloride intermediate (d1):

[0296] Intermediate 5a (500.0 mg, 1.38 mmol) was dissolved in 30 mL of CH2Cl2, and then oxalyl chloride (350.94 mg, 2.77 mmol) was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain 0.5 g of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoyl chloride (intermediate d1), with a yield of 95.15%.

[0297] Step (4): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzene ester:

[0298] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoyl chloride (785.71 mg, 2.07 mmol) CH2Cl2 was added to the reaction system, and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was performed to obtain 0.5 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate, with a yield of 56.50%.

[0299] Example 41: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-5-(2-chloro-4-(trifluoromethyl)phenoxy)benzoate (i.e., compound A41), comprising the following steps:

[0300] Step (1): Referring to step (1) of Example 40, methyl 5-hydroxy-2-nitrobenzoate is replaced with methyl 2-chloro-5-hydroxybenzoate:

[0301] Step (2): Referring to step (2) of Example 40, intermediate 4a is replaced with intermediate 4b:

[0302] Step (3): Referring to step (3) of Example 40, intermediate 5a is replaced with intermediate 5b:

[0303] Step (4): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-5-(2-chloro-4-(trifluoromethyl)phenoxy)benzoate:

[0304] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-chloro-5-(2-chloro-4-(trifluoromethyl)phenoxy)benzoyl chloride (763.90 mg, 2.07 mmol) CH2Cl2 was added to the reaction system and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.53 g of 1,4-dioxo-1,4-dihydronaphth-2-yl-2-chloro-5-(2-chloro-4-(trifluoromethyl)phenoxy)benzoate, with a yield of 60.88%.

[0305] Example 42: A method for preparing 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-methylbenzoate (i.e., compound A42), comprising the following steps:

[0306] Step (1): Referring to step (1) of Example 40, methyl 2-chloro-5-hydroxybenzoate is replaced with methyl 5-hydroxy-2-methylbenzoate:

[0307] Step (2): Referring to step (2) of Example 40, intermediate 4a is replaced with intermediate 4c;

[0308] Step (3): Referring to step (3) of Example 40, intermediate 5a is replaced with intermediate 5c;

[0309] Step (4): Preparation of 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-methylbenzoate:

[0310] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-methylbenzoyl chloride (721.70 mg, 2.07 mmol) CH2Cl2 was added to the reaction system and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.51 g of 1,4-dioxo-1,4-dihydronaphth-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-methylbenzoate, with a yield of 60.81%.

[0311] Example 43: A method for preparing 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid (i.e., compound A43), comprising the following steps:

[0312] Step (1): Preparation of 4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenol intermediate (6a):

[0313] Hydroquinone (1.0 g, 9.08 mmol), K₂CO₃ (3.77 g, 27.24 mmol), and KI (301.52 mg, 1.82 mmol) were dissolved in 40 mL of DMF and reacted at room temperature for half an hour. Then, 2-chloro-5-(trifluoromethyl)pyridine was added, and the reaction solution was heated to 80–100 °C and reacted for 10 hours. After the reaction was completed, the solution was cooled to room temperature, and then ethyl acetate and water were added to extract the solution. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated, and then subjected to column chromatography to obtain 4.12 g of 4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenol (intermediate 6a), with a yield of 88.79%.

[0314] Step (2): Preparation of intermediate (7a) of methyl 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionate:

[0315] Intermediate 6a (2.0 g, 7.84 mmol), K₂CO₃ (1.62 g, 11.76 mmol), and KI (130.10 mg, 783.71 μmol) were dissolved in 50 mL of DMF. After reacting at room temperature for half an hour, methyl 2-chloropropionate (1.25 g, 10.19 mmol) was added. The reaction solution was then heated to 80–100 °C and reacted for 10 hours. After the reaction was completed, the solution was cooled to room temperature, and then ethyl acetate and water were added to extract the solution. The organic layer was separated, washed with saturated ammonium chloride solution, dried, concentrated, and then subjected to column chromatography to obtain 2.08 g of methyl 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionate (intermediate 7a), with a yield of 77.90%.

[0316] Step (3): Preparation of intermediate (8a) of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid:

[0317] Intermediate 7a (2.0 g, 5.86 mmol) was dissolved in 40 mL of CH3OH, and then LiOH·H2O (122.95 mg, 2.93 mmol) was added. The reaction solution was heated to 60 °C and reacted for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into ice. The pH of the aqueous solution was adjusted to 2-4 with hydrochloric acid while stirring, and a solid gradually precipitated out. The obtained solid was filtered and dried under vacuum to obtain 1.63 g of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid (intermediate 8a), with a yield of 84.90%.

[0318] Step (4): Preparation of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionyl chloride intermediate (e1):

[0319] Intermediate 8a (500.0 mg, 1.38 mmol) was dissolved in 30 mL of CH2Cl2, and then oxaloyl chloride (387.83 mg, 2.77 mmol) was slowly added to the solution with stirring. Then, two drops of DMF solution were added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the reaction system was concentrated under reduced pressure to obtain 0.50 g of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionyl chloride (intermediate e1), with a yield of 94.66%.

[0320] Step (5): Preparation of 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid:

[0321] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionyl chloride (714.61 mg, 2.07 mmol) CH2Cl2 was added to the reaction system and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.26 g of 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid, with a yield of 30.98%.

[0322] Example 44: A method for preparing 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid (i.e., compound A44), comprising the following steps:

[0323] Step (1): Referring to step (1) of Example 43, hydroquinone is replaced with resorcinol;

[0324] Step (2): Referring to step (2) of Example 43, intermediate 6a is replaced with intermediate 6b;

[0325] Step (3): Referring to step (3) of Example 43, intermediate 7a is replaced with intermediate 7b;

[0326] Step (4): Referring to step (4) of Example 43, intermediate 8a is replaced with intermediate 8b;

[0327] Step (5): Preparation of 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid:

[0328] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(3-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionyl chloride (714.61 mg, 2.07 mmol) CH2Cl2 was added to the reaction system and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.25 g of 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid, with a yield of 30.26%.

[0329] Example 45: A method for preparing 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(4-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid (i.e., compound A45), comprising the following steps:

[0330] Step (1): Referring to step (1) of Example 43, 2-chloro-5-(trifluoromethyl)pyridine is replaced with 2,3-dichloro-5-(trifluoromethyl)pyridine;

[0331] Step (2): Referring to step (2) of Example 43, intermediate 6a is replaced with intermediate 6c;

[0332] Step (3): Referring to step (3) of Example 43, intermediate 7a is replaced with intermediate 7c;

[0333] Step (4): Referring to step (4) of Example 43, intermediate 8a is replaced with intermediate 8c;

[0334] Step (5): Preparation of 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(4-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid:

[0335] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(4-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionyl chloride (785.81 mg, 2.07 mmol) CH2Cl2 was added to the reaction system and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.23 g of 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(4-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid, with a yield of 25.78%.

[0336] Example 46: A method for preparing 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid (i.e., compound A46), comprising the following steps:

[0337] Step (1): Referring to step (1) of Example 43, hydroquinone is replaced with resorcinol, and 2-chloro-5-(trifluoromethyl)pyridine is replaced with 2,3-dichloro-5-(trifluoromethyl)pyridine;

[0338] Step (2): Referring to step (2) of Example 43, intermediate 6a is replaced with intermediate 6d;

[0339] Step (3): Referring to step (3) of Example 43, intermediate 7a is replaced with intermediate 7d;

[0340] Step (4): Referring to step (4) of Example 43, intermediate 8a is replaced with intermediate 8d;

[0341] Step (5): Preparation of 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid:

[0342] 2-Hydroxy-1,4-naphthoquinone (300.0 mg, 1.72 mmol) and Et3N (209.18 mg, 2.07 mmol) were dissolved in 20 mL of CH2Cl2 and reacted at room temperature for 10 minutes. Then, 10 mL of 2-(3-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionyl chloride (785.81 mg, 2.07 mmol) CH2Cl2 was added to the reaction system and the reaction was continued at room temperature for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, dissolved in 100 mL of CH2Cl2, and extracted with 100 mL of H2O. The organic layer was separated, concentrated under reduced pressure, and column chromatography was used to obtain 0.27 g of 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(3-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid, with a yield of 30.27%.

[0343] The structural and molecular formulas of the target compounds obtained in the above examples are shown in Table 1, and their physicochemical properties and spectral information are also shown in Table 1.

[0344] Table 1. Molecular formulas and structural formulas of the target compounds obtained in Examples 1-46

[0345]

[0346]

[0347]

[0348]

[0349]

[0350]

[0351]

[0352] Table 2. Physicochemical properties and spectroscopic data of the target compounds obtained in Examples 1-46

[0353]

[0354]

[0355]

[0356]

[0357]

[0358]

[0359]

[0360]

[0361]

[0362] Pre-seeding activity assay of target compounds:

[0363] This experiment employed the petri dish method, using various weeds as test subjects. Germinated seeds were placed in 12-well plates (2.3 cm in diameter) (6 seeds per well). Two layers of filter paper were placed in each well of the 12-well plate, with the filter paper impregnated with 1 mL of 100 μg / mL and 10 μg / mL test compound solutions, respectively. Water was used as a blank control; atrazine and trifluralin were used as positive controls. After adding the drugs, the 12-well plates were placed in an artificial climate incubator, under conditions of 75% relative humidity, with automatic cycling of 16 h of light (27℃) and 8 h of darkness (25℃). After 5 days of observation, the stem and root lengths of the weed seeds were measured with a ruler, and the inhibition rate was calculated. Each experiment had three parallel groups, and each experiment was repeated three times.

[0364] Table 3. Pre-emergence herbicidal activity of target compounds in Examples 1-46 at 100 μg / mL.

[0365]

[0366]

[0367] Table 4. Pre-emergence herbicidal activity of target compounds in Examples 1-46 at 10 μg / mL.

[0368]

[0369]

[0370] Post-seeding activity test of target compound:

[0371] This experiment employed a spraying method, using various weeds as test targets. Weed seeds were directly sown and evenly scattered in 8x8cm plastic pots filled two-thirds with organic substrate, and then grown in a greenhouse. Both grasses and broadleaf weeds were ready for testing when they reached the two- to three-leaf stage. The compounds were dissolved in 100 μL DMF and diluted with 0.1% Tween-80 to a dosage of 37.5–300 g ai / ha. Atrazine and trifluralin were used as positive controls and target compounds, respectively, to treat all weeds. After 15 days in the greenhouse, the herbicidal activity of the treated weeds was evaluated visually against the control (CK) group, repeated three times.

[0372] Table 5. Post-emergence herbicidal activity of the target compounds in Examples 1-46

[0373]

[0374]

[0375] Crop safety testing of target compounds:

[0376] This experiment employed a spraying method, using various crops as test subjects. Crop seeds were directly sown and evenly scattered in 8x8cm plastic pots filled two-thirds with organic substrate soil, and then grown in a greenhouse. The compounds were dissolved in 100 μL of DMF and diluted with 0.1% Tween-80 to a dose of 150 g ai / ha. Atrazine and trifluralin were used as positive controls and target compounds, respectively, to treat all weeds. After 30 days in the greenhouse, the safety of the treated crops was evaluated visually, using a control group (CK). This process was repeated three times.

[0377] Table 6. Crop safety of the target compound in Example 40 at a dose of 150 g ai / ha.

[0378]

[0379] Tables 3 and 4 show that all target compounds exhibited significantly better inhibitory effects on broadleaf weeds than on grass weeds at both 100 μg / mL and 10 μg / mL concentrations. At 100 μg / mL, compounds A27, A33, A38, A40, and A41 demonstrated excellent pre-emergence inhibitory effects on barnyard grass, crabgrass, amaranth, and purslane, with weeds showing virtually no growth and inhibition rates exceeding 70%, superior to the positive control atrazine and comparable to the positive control trifluralin. At 10 μg / mL, compounds A40 and A41 still showed excellent pre-emergence inhibitory effects on barnyard grass, crabgrass, amaranth, and purslane, comparable to the positive control trifluralin. Table 5 shows that at 300 g... At a dosage of ai / ha, compounds A40, A43, A44, and A45 exhibited excellent herbicidal activity against barnyard grass, crabgrass, foxtail, velvetleaf, amaranth, and purslane, causing the weeds to wither and their growth to be severely inhibited, with inhibition rates reaching 90%, superior to the positive control atrazine. Among them, compounds A40 and A44, as target compounds, still showed excellent herbicidal activity against barnyard grass, crabgrass, foxtail, velvetleaf, amaranth, and purslane at a concentration of 75 ga.i. / ha, comparable to the positive control trifluralin. As shown in Table 6, trifluralin caused very serious damage to broadleaf crops, while compound A40 showed better crop safety than trifluralin in rice, corn, wheat, peanut, soybean, and cotton, with relatively better safety in broadleaf crops.

[0380] In summary, this series of natural naphthoquinone derivatives possesses simple structures and preparation processes, low production costs, and excellent post-emergence herbicidal activity. Therefore, these compounds can be further developed as novel PSII inhibitors, post-emergence herbicides, and selective herbicides, enabling their application in a wider range of farmlands.

[0381] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments without departing from the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A natural naphthoquinone derivative, characterized in that, Selected from the following compounds: Compound A43: 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(4-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid; Compound A44: 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester of 2-(3-((5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid; Compound A45: 1,4-dioxo-1,4-dihydronaphth-2-yl ester of 2-(4-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)phenoxy)propionic acid; Compound A46: 2-(3-((3-chloro-5-fluoropyridin-2-yl)oxy)phenoxy)propionic acid 1,4-dioxo-1,4-dihydronaphthyl-2-yl ester.

2. The application of a natural naphthoquinone derivative as described in claim 1 in the preparation of herbicides and weed growth enzyme inhibitors, wherein the weeds are barnyard grass, velvetleaf, amaranth, purslane, and foxtail grass.

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