Indole-3-acetamide derivatives, processes for their preparation and uses thereof

Abstract

The application provides an indole-3-acetamide derivative and a preparation method and application thereof, and provides an indole-3-acetamide derivative with a structure shown in formula (7). The natural product indole ring is used as a core skeleton, and a series of indole-3-acetamide compounds are obtained. The experimental results show that the compound provided by the application has good herbicidal activity, and has a good application prospect in the fields of agriculture, horticulture and forestry.

Description

Technical Field

[0001] The technical solution of the present invention relates to indole-3-acetamide compounds, specifically to an indole-3-acetamide derivative and its preparation method and application. Background Technology

[0002] The development of new pesticides is a crucial means of my country's strategy to reduce pesticide use and increase efficiency, and it is also an important guarantee for the implementation of my country's policy to replace highly toxic pesticides. It is of great value for the prevention and control of agricultural pests, diseases, and weeds, and for ensuring bumper harvests (J. Agric. Food Chem. 2023, 71, 276–287.). For example, Central China Normal University and Xinda Agrochemical Company jointly developed the herbicide quinclorac, which effectively solved the technical problem of controlling noxious weeds in sorghum fields (J. Agric. Food Chem. 2010, 58, 2696–2702.); Qingyuan Nongguan Company's new herbicide varieties, such as cyproconazole and benzoyl fluroxypyr, have had a significant impact on agricultural production worldwide.

[0003] Target-based pesticide molecular design is one of the important approaches to the creation of new pesticides. From the 1950s to the 1990s, about 20 existing targets for commercially available herbicides were discovered, and numerous herbicide varieties were developed based on these targets. For example, protoporphyrinogen oxidase inhibitors and acetyl-CoA carboxylase inhibitors. However, the excessive use of existing target herbicides has caused serious weed resistance problems and created a vicious cycle. Therefore, sustainable agricultural development urgently requires the development of new, efficient, environmentally friendly herbicides with novel mechanisms of action (J. Agric. Food Chem. 2020, 68(18):5059–5067.).

[0004] Natural products, with their unique structures, abundant biological activities, and novel mechanisms of action, are an important source for the creation of new green pesticides. Therefore, using natural product skeletons or introducing active natural product skeletons into pesticide lead molecules has become an important method for creating novel environmentally friendly pesticides (J. Agric. Food Chem. 2023, 71, 267–275). Transketolases are important enzymes in plant carbon metabolism and the Calvin cycle. Changes in their activity significantly affect plant growth rate, phenylalanine and aromatic amino acid metabolites, and transketolases have been shown to be a novel potential target for herbicides, enabling the molecular design of herbicidal active compounds using transketolases as targets (J. Agric. Food Chem. 2022, 70, 12819-12829).

[0005] Therefore, researching and exploring novel herbicides containing natural frameworks is of great significance. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a new type of indole-3-acetamide derivative, its preparation method and application. The indole-3-acetamide derivative provided by this invention has good herbicidal activity and is of great significance in the fields of agriculture, horticulture and forestry.

[0007] This invention provides an indole-3-acetamide derivative, its preparation method, and its application. The indole-3-acetamide derivative with the structure shown in formula (7) provided by this invention uses the indole ring of natural products as the core skeleton to obtain a series of indole-3-acetamide compounds. Experimental results show that the compounds provided by this invention have good herbicidal activity and have good application prospects in the fields of agriculture, horticulture, and forestry.

[0008] This invention provides an indole-3-acetamide derivative having the structure shown in formula (7):

[0009]

[0010] Among them, R 1 Selected from 4-fluorophenyl, 2,4-dichlorophenyl, 6-chloropyridin-3-yl or cyclopropyl;

[0011] R 2 It is selected from 4-trifluorophenyl, pyridin-3-methylene, 1-methyl-1H-pyrazol-5-yl, furan-2-methylene, thiophene-2-methylene or cyclopropyl.

[0012] Preferably, formula (7) has the following structure:

[0013]

[0014] This invention also provides a method for synthesizing an indole-3-acetamide derivative, comprising:

[0015] 1) Methyl indole-3-acetate with the structure of formula (1) is mixed and reacted with a halogenated compound having the structure of formula (2) to obtain a compound with the structure of formula (3);

[0016]

[0017] Among them, R 1 Selected from: 4-fluorophenyl, 2,4-dichlorophenyl, 6-chloropyridin-3-yl or cyclopropyl;

[0018] 2) Convert compounds with the structure of formula (3) into compounds with the structure of formula (4);

[0019]

[0020] 3) React the compound with the structure of formula (4) with oxalyl chloride to obtain the compound with the structure of formula (5);

[0021]

[0022] 4) By mixing and reacting the compound with the compound of formula (6) and the compound of formula (5), a compound with the formula (7) is obtained, which is an indole-3-acetamide derivative.

[0023] R 2 NH2 formula (6),

[0024] Among them, R 2 Selected from: 4-trifluorophenyl, pyridin-3-methylene, 1-methyl-1H-pyrazol-5-yl, furan-2-methylene, thiophene-2-methylene or cyclopropyl.

[0025] Specifically, the reaction equation is as follows:

[0026]

[0027] Among them, R 1 Selected from: 4-fluorophenyl, 2,4-dichlorophenyl, 6-chloropyridin-3-yl or cyclopropyl; R 2 Selected from: 4-trifluorophenyl, pyridin-3-methylene, 1-methyl-1H-pyrazol-5-yl, furan-2-methylene, thiophene-2-methylene or cyclopropyl;

[0028] The specific methods for synthesizing and determining the bioactivity of the indole-3-acetamide derivative 7 of the present invention are divided into the following steps: A. Preparation method of compound 3:

[0029] In a 100 mL single-necked flask, 10.57 mmol of indole-3-acetic acid methyl ester was added, followed by a certain volume of N,N-dimethylformamide to dissolve it. Under magnetic stirring, 15.86 mmol of a halogenated compound and 12.68 mmol of potassium hydroxide were added sequentially. The halogenated compound was selected from 4-fluorochlorobenzyl, 2,4-dichlorochlorobenzyl, 2-chloro-5-chloromethylpyridine, and chloromethylcyclopropane. The reaction progress was monitored by TLC. After the reaction was completed, 50 mL of ethyl acetate was added to the reaction flask to dissolve the compound. The mixture was washed with saturated brine, extracted, and separated into layers. The organic layer was dried with anhydrous sodium sulfate, filtered under reduced pressure, and the solvent was removed by rotary evaporation. The crude product was purified by column chromatography to obtain indole carboxylic acid ester derivative 3. The eluent was petroleum ether:ethyl acetate 5:1 to 15:1, with a yield of 67-85%. The amount of compound 3 prepared and the volume of the reaction vessel were increased or decreased proportionally.

[0030] B. Preparation method of compound 4:

[0031] In a 100 mL round-bottom flask, 1.00 mmol of indole carboxylic acid ester derivative 3 was added, followed by the addition of a certain volume of CH3CH2OH solvent to dissolve it. 5.00 mmol of 10% potassium hydroxide solution was slowly added dropwise. The reaction was stirred continuously at room temperature, and the reaction progress was monitored by TLC. After the reaction was complete, the solvent was removed by rotary evaporation under reduced pressure. 10 mL of distilled water was added to dissolve the residue, and the pH of the solution was adjusted to 5 using concentrated HCl. The solution was transferred to a separatory funnel, and 50 mL of ethyl acetate was added to dissolve it. The mixture was washed with 40 mL × 3 saturated NaCl solution, and the mixture was extracted by shaking. The organic layer was dried over anhydrous Na2SO4, filtered, and rotary evaporated under reduced pressure. No further purification was required to obtain indole carboxylic acid derivative 4, with a yield of 95-97%. The amount of compound 4 prepared and the volume of the reaction vessel were adjusted proportionally.

[0032] C. Preparation method of compound 5:

[0033] In a 100 mL round-bottom flask, 1.00 mmol of indole carboxylic acid derivative 4 was added and dissolved in a certain volume of dry dichloromethane. The mixture was magnetically stirred and, under ice bath conditions, 3.00 mmol of anhydrous dichloromethane solution of oxalyl chloride was added dropwise to the above solution. The reaction progress was monitored by TLC. After the reaction was completed, the solvent was removed by rotary evaporation under reduced pressure. No further purification was required to obtain acyl chloride intermediate 5 in 100% yield. The amount of compound 5 prepared and the volume of the reaction vessel were increased or decreased proportionally.

[0034] D. Preparation method of compound 7:

[0035] In a 100 mL single-necked flask, 1.2 mmol of a certain amino compound, dichloromethane, and 1.2 mmol of triethylamine were added sequentially. The amino compound was selected from p-trifluoromethylaniline, 3-aminomethylpyridine, 1-methyl-5-aminopyrazole, 2-thiophene-methylamine, 2-furan-methylamine, and cyclopropylamine. The mixture was magnetically stirred, and then, under ice bath conditions, a dichloromethane solution containing 1.0 mmol of acyl chloride intermediate 5 was added dropwise to the above solution. The reaction progress was monitored by TLC. After the reaction was completed, 50 mL of dichloromethane solvent was added, and the mixture was washed with saturated NaCl solution, extracted, and the organic layer was dried with anhydrous Na2SO4. The mixture was then filtered, evaporated under reduced pressure, and the crude product was purified by column chromatography to obtain the target compound 7. The eluent was petroleum ether:ethyl acetate at a ratio of 15:1 to 5:1, with a yield of 54-90%. The amount of compound 7 prepared and the volume of the reaction vessel were increased or decreased proportionally.

[0036] E. Herbicidal activity determination of the indole-3-acetamide derivative 7 of the present invention:

[0037] The herbicidal activity of the indole-3-acetamide derivative 7 of this invention was assessed using the small-cup method and the foliar spray method. The specific steps were as follows: 20 mg of sample was dissolved in 1 mL of N,N-dimethylformamide to prepare a 20 g / L stock solution. Then, the stock solution was diluted to 100 mg / L using an aqueous solution containing 0.1% Tween 80 emulsifier. Small-cup method: Ten uniformly germinating weed seeds were selected with tweezers and evenly distributed on filter paper in a 50 mL beaker. Each treatment was repeated three times. 1 mL of reagent solution was slowly dripped onto the filter paper using a pipette. All treatments were placed in a climate chamber with humidity control at 25 ± 0.5 °C, 60 ± 5%, and a light intensity with a day-night ratio of 16:8. After 7 days, the root and stem lengths of the weeds were measured, and the root and stem inhibition rates of the compound were calculated. Foliar spray method: The concentration used was 150 g effective content / ha. In the foliar treatment method, when dicotyledonous weeds reached the two-leaf stage and monocotyledonous weeds reached the 3-5-leaf stage, a mobile sprayer was used to evenly spray the test agent onto the weed leaves. A solution without added reagents was used as a blank control. Each treatment was repeated three times. The treated weeds were then incubated in an artificial climate chamber. After 14 days, the degree of inhibition of weed growth was assessed visually. The test plants were most typical weeds that actually occur in the fields in my country's agricultural production. Their names are as follows: Digitaria sanguinalis L., and Amaranthus retroflexus L.

[0038]

[0039] The beneficial effects of this invention are: the indole-3-acetamide derivative 7 was derivatized and synthesized, and the herbicidal activity of the indole-3-acetamide derivative 7 was screened.

[0040] This invention provides more specific examples of the synthesis, bioactivity, and application of indole-3-acetamide derivative 7 through specific preparation and bioactivity assays. These examples are for illustrative purposes only and are not intended to limit the invention. In particular, the bioactivity is merely illustrative and not intended to limit this patent. Specific implementation methods are as follows:

[0041] Example 1: Preparation method of compound 3:

[0042] In a 100 mL single-necked flask, 10.57 mmol of indole-3-acetic acid methyl ester was added, followed by a certain volume of N,N-dimethylformamide to dissolve it. Under magnetic stirring, 15.86 mmol of a halogenated derivative and 12.68 mmol of potassium hydroxide were added sequentially. The halogenated derivative was selected from 4-fluorochlorobenzyl, 2,4-dichlorochlorobenzyl, 2-chloro-5-chloromethylpyridine, and chloromethylcyclopropane. The reaction was monitored by TLC. After the reaction was complete, 50 mL of ethyl acetate was added to the reaction flask to dissolve the derivative. The mixture was washed with saturated brine, and the layers were extracted and separated. The organic layer was dried over anhydrous sodium sulfate, filtered under reduced pressure, and the solvent was removed by rotary evaporation. The crude product was purified by column chromatography to obtain indole carboxylic acid ester derivative 3, with petroleum ether:ethyl acetate 5:1–15:1 as the eluent, yielding 67-85%. 1 When =4-fluorophenyl, the NMR data are as follows: 1 ¹H NMR (CD₃Cl, 400MHz) δ 7.65 (d, J = 7.8 Hz, 1H), 7.25 (d, J = 7.1 Hz, 1H), 7.21 (t, J = 7.3 Hz, 1H), 7.16 (t, J = 7.0 Hz, 1H), 7.12–7.09 m (3H), 6.99 (t, J = 8.6 Hz, 2H), 5.25 (s, 2H), 3.81 (s, 2H), 3.72 (s, 3H). The amount of compound 3 prepared and the volume of the reaction vessel were increased or decreased proportionally.

[0043] Example 2: Preparation method of compound 4:

[0044] In a 100 mL round-bottom flask, 1.00 mmol of indole carboxylic acid ester derivative 3 was added. Then, a certain volume of CH3CH2OH solvent was added to dissolve it. 5.00 mmol of 10% potassium hydroxide solution was slowly added dropwise. The reaction was carried out at room temperature with continuous stirring. The reaction progress was monitored by TLC. After the reaction was completed, the solvent was removed by rotary evaporation under reduced pressure. 10 mL of distilled water was added to dissolve the residue. The pH of the solution was adjusted to 5 using concentrated HCl. The solution was transferred to a separatory funnel, and 50 mL of ethyl acetate was added to dissolve it. The solution was washed with 40 mL × 3 saturated NaCl solution, and extracted by shaking. The organic layer was dried over anhydrous Na2SO4, filtered, and rotary evaporated under reduced pressure. No further purification was required to obtain indole carboxylic acid derivative 4, with a yield of 95-97%. 1 When =4-fluorophenyl, the NMR data are as follows: 1¹H NMR (DMSO-d⁶, 400 MHz) δ 7.63 (d, J = 7.8 Hz, 1H), 7.25 (d, J = 10.9 Hz, 1H), 7.20 (t, J = 7.4 Hz, 1H), 7.15 (t, J = 7.1 Hz, 1H), 7.12–7.03 (m, 3H), 6.98 (t, J = 8.6 Hz, 2H), 5.25 (s, 2H), 3.81 (s, 2H). The amount of compound 4 prepared and the volume of the reaction vessel were increased or decreased proportionally.

[0045] Example 3: Preparation method of compound 5:

[0046] In a 100 mL round-bottom flask, 1.00 mmol of indole carboxylic acid derivative 4 was added and dissolved in a certain volume of dry dichloromethane. The mixture was magnetically stirred, and under ice bath conditions, 3.00 mmol of anhydrous dichloromethane solution of oxalyl chloride was added dropwise. The reaction was monitored by TLC. After the reaction was complete, the solvent was removed by rotary evaporation under reduced pressure. No further purification was required to obtain acyl chloride intermediate 5 in 100% yield. 1 When =4-fluorophenyl, the NMR data are as follows: 1 ¹H NMR (400MHz, CDCl₃) δ 7.63 (d, J = 7.8 Hz, 1H), 7.25 (d, J = 10.9 Hz, 1H), 7.20 (t, J = 7.4 Hz, 1H), 7.15 (t, J = 7.1 Hz, 1H), 7.12–7.03 (m, 3H), 6.98 (t, J = 8.6 Hz, 2H), 5.25 (s, 2H), 3.81 (s, 2H). The amount of compound 5 prepared and the volume of the reaction vessel were increased or decreased proportionally.

[0047] Example 4: Preparation method of compound 7:

[0048] In a 100 mL single-necked flask, 1.2 mmol of a certain amino compound, dichloromethane, and 1.2 mmol of triethylamine were added sequentially. The amino compound was selected from: p-trifluoromethylaniline, 3-aminomethylpyridine, 1-methyl-5-aminopyrazole, 2-thiophene-methylamine, 2-furan-methylamine, and cyclopropylamine. The mixture was magnetically stirred, and then, under ice bath conditions, a dichloromethane solution containing 1.0 mmol of acyl chloride intermediate 5 was added dropwise. The reaction progress was monitored by TLC. After the reaction was complete, 50 mL of dichloromethane solvent was added, and the mixture was washed with saturated NaCl solution, extracted, and the organic layer was dried over anhydrous Na2SO4. The mixture was filtered, evaporated under reduced pressure, and the crude product was purified by column chromatography to obtain the target compound 7. The eluent was petroleum ether:ethyl acetate 15:1-5:1, with a yield of 54-90%. 1 When = 4-fluorophenyl, R 2When =4-trifluorophenyl, the NMR data are as follows: 1 ¹H NMR (400MHz, CDCl₃) δ 7.66–7.55 (m, 2H), 7.48 (dd, J = 20.2, 8.6Hz, 4H), 7.35 (d, J = 8.3Hz, 1H), 7.28 (d, J = 7.6Hz, 1H), 7.19 (t, J = 7.4Hz, 1H), 7.13 (d, J = 9.4Hz, 3H), 7.01 (t, J = 8.6Hz, 2H), 5.31 (s, 2H), 3.90 (s, 2H). The amount of compound 7 prepared and the volume of the reaction vessel were increased or decreased proportionally. The physicochemical and structural parameters of compound 7 are shown in Table 1.

[0049] Example 5: Herbicidal activity test results of indole-3-acetamide derivative 7 of the present invention:

[0050] The common weeds tested in this invention are as follows: *Digitaria sanguinalis* L. (Ds) and *Amaranthus retroflexus* L. (Ar). These weeds are highly representative and can represent most weeds occurring in agricultural fields. Herbicidal activity was tested using the small-cup method and the foliar treatment method.

[0051] The results of the small-cup method are shown in Table 2. At 100 μg / mL, except for compounds 7c, 7d, 7e, 7l, 7u, and 7x, most of the indole-3-acetamide derivatives synthesized in this invention showed root and stem inhibition rates of over 70% against *Digitaria rubra* and *Amaranthus retroflexus*, demonstrating good herbicidal activity. Among them, compounds 7g, 7h, 7p, 7r, and 7t showed inhibition rates of 80-85% against *Digitaria rubra* and *Amaranthus retroflexus*, comparable to the positive control. Furthermore, at a concentration of 100 mg / L, compounds 7m, 7n, and 7q showed inhibition rates of over 85% against *Digitaria rubra* and *Amaranthus retroflexus*, superior to the positive control. More importantly, at the same concentration, compounds 7m and 7q showed the best herbicidal effect against *Digitaria rubra* and *Amaranthus retroflexus*, with inhibition rates exceeding 95%.

[0052] At a dosage of 150 g effective content / ha, most of the indole-3-acetamide derivatives of this invention exhibited good herbicidal activity when applied via foliar spraying. The results are shown in Table 2. Except for compounds 7c, 7e, and 7f, which showed less than 50% inhibition of barnyardgrass, and compounds 7d, 7f, and 7l, which showed less than 50% inhibition of amaranth, most compounds showed herbicidal efficacy greater than 50% against both barnyardgrass and amaranth. Among them, compounds 7h, 7n, 7p, 7q, and 7r showed inhibition rates of 70-89% against both barnyardgrass and amaranth, comparable to the positive control. More significantly, compound 7m showed even better herbicidal efficacy against both barnyardgrass and amaranth (inhibition rate exceeding 90%). Because compound 7m has a higher ClogP value (5.307) than compound 7q (3.638), it exhibits greater lipophilicity, which may promote its absorption and translocation within plants. Therefore, in foliar spraying, 7m demonstrates superior herbicidal efficacy compared to 7q. Furthermore, 7m exhibits high transketolase inhibitory activity, suggesting that compound 7m is a promising candidate for a highly effective herbicide targeting transketolases.

[0053] Example 6: Application of the indole-3-acetamide derivative 7 of the present invention in the preparation of compound herbicides in any one or more combinations of agriculturally acceptable adjuvants and the following commercially available herbicides:

[0054] The herbicides mentioned are selected from nicosulfuron, bensulfuron, methylsulfuron, metsulfuron-methyl, penflusulfuron, metolachlor, acetochlor, butachlor, isopropyl metolachlor, trifluralin, mesotrione, methylsulfuron, benzoyl sulfide, pendimethalin, atrazine, promethazine, cypermethrin, atrazine, chlorfenapyr, oxyfluorfen, trifluralin, quizalofop-P-ethyl, ethoxysulfuron, pyrazosulfuron, isopropylpyrazosulfuron, imazalil, imazalil ethoxysulfuron, imazalil, imazalil quinclorac, methoxysulfuron, methyl imazalofop-P-ethyl, pyrimethanil, pyrazosulfuron, pyrimethanil, pyrimisulfuron, pyrimisulfuron-methyl, cyhalofop-P-ethyl, betaine, betaine, oat valerate, dimethomorph, barnyardgrass, quizalofop-P-ethyl, haloxyfop-P-ethyl, haloxyfop-P-ethyl, oxadixyl The herbicides include quizalofop-P-ethyl, quizalofop-P-ethyl, fluroxypyr, flupyridaben, fluazinam, thiamethoxam, flupyridine, paraquat, glyphosate, barnyardgrass, fluroxypyr, propyzoxystrobin, fluthiamethoxam, methyl methacrylate, pyrazosulfuron, pyrazosulfuron, benzylpyridinium, isoxaflutole, isoxaflutole, bromobenzonitrile, etc.; the total mass percentage of the indole-3-acetamide derivative 7 of the present invention in the obtained compound herbicide is 1%-90%, and the ratio of the indole-3-acetamide derivative 7 of the present invention to the commercial herbicide is 1%:99% to 99%:1% by mass percentage; the applicable formulation of the compound herbicide is selected from any one of the following formulations: wettable powder, microcapsule suspension, dispersible liquid. Formulations, dispersible solids, seed treatment emulsions, water-in-oil emulsions, large granules, microemulsions, oil suspensions, water-soluble granules, soluble concentrates, water-dispersible granules, toxic grains, aerosols, sustained-release blocks, capsules, dry-mix seed powders, emulsifiable concentrates, electrostatic sprays, water-in-oil emulsions, oil-in-water emulsions, smoke cans, fine granules, smoke candles, smoke tubes, smoke sticks, seed treatment suspensions, smoke sheets, smoke pellets, aeration agents, drifting powders, ointments, thermal fogging agents, solid / liquid mixtures, liquid / liquid mixtures, cold fogging agents, solid / solid mixtures, lacquer, seed treatment liquids, microparticles, oil-dispersible powders, concentrated colloids, pouring agents, coatings, suspension emulsions, film-forming oils, soluble powders, water-soluble seed treatment powders The compound herbicides are formulated with a variety of herbicides, including ultra-low volume suspension concentrates, tracking powders, ultra-low volume liquids, vapor release agents, and wet seed dressing water-dispersible powders. The applicable plants for these compound herbicides are selected from rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, sugar beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, sugar beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus, peach, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.The compound herbicide is suitable for controlling the following weeds: Gramineae weeds: crabgrass, foxtail grass, goosegrass, barnyard grass, barnyard grass, wild oats, wild clover, golden foxtail grass, long-awned barnyard grass, and wild oats; Broadleaf weeds: amaranth, purslane, lambsquarters, shepherd's purse, iron amaranth, cocklebur, ragweed, amaranth, velvetleaf, kochia, black nightshade, willow-leaved spinach, chickweed, elm, water spinach, sorrel, bindweed, field bindweed, and dodder; Cyperaceae weeds: *Sedge sedge*, *Sedge sedge*, water sedge, pigweed, and water onion, etc.

[0055] Table 1. Chemical structure and physicochemical parameters of the indole-3-acetamide derivative 7 of the present invention.

[0056]

[0057]

[0058] Table 2. Herbicidal activity of the indole-3-acetamide derivative 7 of the present invention against barnyardgrass and amaranth (small cup method: inhibition rate / %) at 100 μg / mL

[0059]

[0060] Table 3. Herbicidal activity of the indole-3-acetamide derivative 7 of the present invention by foliar spraying (inhibition rate / %) per 150 g effective content / hectare

[0061]

[0062] Inhibition percentage rating scale compared with blank control: ++++≥90%; +++70–89%; ++50–69%; +30–49%; –<30%.

Claims

1. An indole-3-acetamide derivative having the structure shown in formula (7): in, R 1 Selected from 4-fluorophenyl, 2,4-dichlorophenyl, 6-chloropyridin-3-yl or cyclopropyl; R 2 The compound is selected from 4-trifluoromethylphenyl, pyridin-3-methylene, 1-methyl-1H-pyrazol-5-yl, furan-2-methylene, thiophene-2-methylene or cyclopropyl; the compound of formula (7) does not contain the following compounds; 2. The indole-3-acetamide derivative according to claim 1, characterized in that, Equation (7) has the following structure:

3. A method for synthesizing an indole-3-acetamide derivative, comprising: 1) Methyl indole-3-acetate with the structure of formula (1) is mixed and reacted with a halogenated compound having the structure of formula (2) to obtain a compound with the structure of formula (3); Among them, R 1 Selected from: 4-fluorophenyl, 2,4-dichlorophenyl, 6-chloropyridin-3-yl or cyclopropyl; 2) Convert compounds with the structure of formula (3) into compounds with the structure of formula (4); 3) React the compound with the structure of formula (4) with oxalyl chloride to obtain the compound with the structure of formula (5); 4) By mixing and reacting the compound with the compound of formula (6) and the compound of formula (5), a compound with the formula (7) is obtained, which is an indole-3-acetamide derivative. R 2 NH2 formula (6), Among them, R 2 Selected from: 4-trifluoromethylphenyl, pyridin-3-methylene, 1-methyl-1H-pyrazol-5-yl, furan-2-methylene, thiophene-2-methylene or cyclopropyl; the compound of formula (7) does not contain the following compounds; 4. The synthesis method according to claim 3, characterized in that, Step 2) specifically involves dissolving the compound of formula (3) in ethanol, then slowly adding 10% potassium hydroxide solution, reacting at room temperature, monitoring the reaction progress by TLC, removing the solvent by rotary evaporation under reduced pressure after the reaction is complete, adding 10 mL of distilled water to dissolve the residue, adjusting the pH of the solution to 5 using concentrated HCl, and then extracting with ethyl acetate to obtain the compound of formula (4).

5. The synthesis method according to claim 3, characterized in that, Step 3) specifically involves dissolving an indole carboxylic acid derivative having the structure of formula (4) in dichloromethane, and under ice bath conditions, adding dropwise 3.00 mmol of anhydrous dichloromethane solution of oxalyl chloride to the above solution to react and obtain a compound with the structure of formula (5).

6. The synthesis method according to claim 3, characterized in that, Step 4) specifically involves mixing an amino compound of formula (6), dichloromethane, and 1.2 mmol of triethylamine, and under ice bath conditions, adding a dichloromethane solution containing a compound of formula (5) dropwise to the above solution, mixing and reacting to obtain a compound of formula (7).

7. The synthesis method according to claim 3, characterized in that, The compound with the structure of formula (6) is p-trifluoromethylaniline, 3-aminomethylpyridine, 1-methyl-5-aminopyrazole, 2-thiophene-methylamine, 2-furan-methylamine or cyclopropylamine.

8. The synthesis method according to claim 3, characterized in that, The halogenated product having the structure of formula (2) is 4-fluorochlorobenzyl, 2,4-dichlorochlorobenzyl, 2-chloro-5-chloromethylpyridine or chloromethylcyclopropane.

9. The use of an indole-3-acetamide derivative according to any one of claims 1 to 2 or an indole-3-acetamide derivative prepared by the preparation method according to any one of claims 3 to 8 in the preparation of herbicides.

10. A herbicide composition comprising: The indole-3-acetamide derivative according to any one of claims 1 to 2 or the indole-3-acetamide derivative prepared by the preparation method according to any one of claims 3 to 8.

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