Compound for preventing and controlling nematodes or salt thereof, nematicide and application of compound or salt and nematicide

Abstract

The invention discloses a compound for preventing and controlling nematodes or a salt thereof and a nematicide and application thereof, belonging to the technical field of pesticides. The compound or a salt thereof is represented by general formula (1): # imgabs0 # formula (1) wherein R is hydrogen or a methyl group. The invention develops a new compound for preventing and controlling nematodes, the nematicidal activity is remarkably improved, and a good nematicidal effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and in particular to a compound or a salt thereof for controlling nematodes, a nematocide and an application thereof. Background Art

[0002] Plant nematode diseases are plant diseases caused by the invasion and parasitism of plant parasitic nematodes. These nematodes mainly parasitize the roots, stems, leaves and other parts of the plant, resulting in stunted plant growth and development, and reduced yield and quality. Plant nematode diseases are widely distributed around the world, causing serious losses to agricultural production. Currently, there are only about 30 kinds of nematicides in the world, and only more than 10 varieties are commonly used. Due to the single variety and long-term use, plant nematode disease resistance is becoming more and more serious. Therefore, the prior art discloses a nematicidal composition, the application publication number is CN 117479838 A, and the application publication date is 2024.01.30. The active ingredient used in the patent for killing nematodes is a hydrazone derivative, but its activity is insufficient and the nematicidal effect is insufficient. Summary of the Invention

[0003] The purpose of the present invention is to address the problems existing in the prior art and provide a compound or its salt and its nematicide and application for nematode control, which significantly improves the nematicidal activity and has a good nematicidal effect.

[0004] In order to achieve the above-mentioned object of the invention, the compound or its salt for nematode control and the nematocide and its application adopt the following technical solutions:

[0005] A compound for controlling nematodes or a salt thereof, which is represented by the general formula (1):

[0006]

[0007] R in formula (1) is hydrogen or methyl.

[0008] In addition, the present invention provides the use of the compound of formula (1) or its salt in controlling nematodes.

[0009] In addition, the present invention provides the use of a compound of formula (1) or a salt thereof in the preparation of a nematicide.

[0010] In addition, the present invention provides a nematicide containing the compound of formula (1) or a salt thereof as an active ingredient.

[0011] Preferably, the nematicide also includes an inert carrier and an adjuvant. The inert carrier can be a solid carrier or a liquid carrier. The solid carrier can be inorganic mineral powder (such as kaolin, etc.), silica (such as diatomaceous earth, etc.), activated carbon, etc., or a plastic carrier (such as polyethylene, polypropylene, etc.), or some fertilizers (such as ammonium sulfate, urea, ammonium chloride, etc.). These carriers can be used alone or in combination. The liquid carrier can be alcohols (such as ethanol, ethylene glycol, etc.), aliphatic hydrocarbons (such as kerosene, mineral oil, etc.), esters (such as diisopropyl phthalate, dibutyl phthalate, etc.), amides (such as dimethylformamide, dimethylacetamide, etc.). The adjuvant can be polyoxyethylene ether, polyoxyethylene higher fatty acids, alkyl aryl sulfonates, higher alcohol sulfates, etc., and the addition of these adjuvants can play effects such as emulsification, dispersion, dissolution, and penetration.

[0012] In addition, the present invention provides a method for controlling nematodes, comprising applying the compound of formula (1) or a salt thereof to soil, nematodes, plants or crop seeds.

[0013] The compound or salt form of the present invention is applied to the soil to control root-knot nematodes that harm agricultural and horticultural production, such as southern root-knot nematodes, northern root-knot nematodes, peanut root-knot nematodes, etc.; or to control Ditylenchus genus that harm agricultural and horticultural production, such as potato rot nematodes, dipsaci stem nematodes, etc.; or to control Braybody genus nematodes that harm agricultural and horticultural production, such as northern root rot nematodes, chrysanthemum root rot nematodes; or to control globose cyst nematodes that harm agricultural and horticultural production, such as potato golden wireworms, potato cyst nematodes, etc.; or to control Aphelenchoide genus nematodes that harm agricultural and horticultural production, such as rice stem tip nematodes, etc.

[0014] The compound or salt of the present invention is applied together with crop seeds to protect the crop seeds from being harmed by nematode diseases during the growth process, thereby protecting the healthy growth of the plants.

[0015] The compound or salt of the present invention can also be used to prevent and control nematodes occurring on trees, such as pine wood nematodes.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention develops new compounds for nematode control and achieves multi-dimensional breakthroughs in nematocidal activity, stability, and safety through the synergistic effects of nitrile (CN), trifluoromethyl (CF3), multiple nitrogen atoms, and R groups.

[0018] 2. By introducing a nitrile group, the molecular stability is improved and the affinity for the target is increased. At the same time, the strong electron-withdrawing groups (CF3, CN) are combined with nitrogen atoms to provide electronic effects and optimize steric hindrance, thereby improving the nematicidal activity and producing a good nematicidal effect.

[0019] 3. By introducing R groups, the molecular polarity is balanced, the compound is promoted to penetrate the nematode epidermis, the lipid solubility is optimized, the toxicity to non-target organisms is reduced, and the safety is improved. DETAILED DESCRIPTION

[0020] The present invention will be further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0021] Example 1

[0022] The synthetic route of the compound of the present invention is as follows:

[0023]

[0024] Wherein, R is a hydrogen atom or a methyl group;

[0025] The preparation method of the compound of formula (1) specifically comprises the following steps:

[0026] (1) 0.1 mol of raw material a was slowly added to 200 ml of sulfonyl chloride at 25-30°C. The reaction was carried out at 25-30°C for 8 hours. After HPLC detection, the reaction of raw material a was completed. The pressure was reduced to 20 mmHg and the unreacted sulfonyl chloride was distilled off at a distillation temperature of no more than 70°C to obtain product b. 100 ml of DMF was added to dissolve the product and the product was set aside.

[0027] (2) Add 0.2 mol (27.6 g) of dry potassium carbonate and 0.1 mol (13.7 g) of 3-(trifluoromethyl)-1H-1,2,4-triazole to the DMF solution of product b. Under nitrogen protection, slowly heat the mixture to 75-80°C and keep the mixture at this temperature for 4 hours. After HPLC detection, the reaction of product b is complete. Cool the mixture to 25-30°C and filter out the solid insoluble matter (KCl, K2CO3, etc.) in the reaction solution. Add 5 g of activated carbon to the filtrate, heat the mixture to 50-60°C, stir for 2 hours, cool the mixture to 10°C, filter out the supernatant, pour the filtered supernatant into 1000 ml of water, stir while pouring, and stir for 2 hours. A yellow solid precipitates. Filter the yellow solid and dry it under reduced pressure at room temperature to a constant weight to obtain product c. (When R=H, the obtained product c is 21 grams, with a yield of 68%; when R=CH3, the obtained product c is 18 grams, with a yield of 56%).

[0028] (3) Dissolve 0.05 mol of product C in 50 ml of anhydrous ethanol, cool to 0°C, slowly dropwise add 20 g of 80% hydrazine hydrate, complete the addition, react at 0-5°C for 2 hours, then slowly raise the temperature to 35-40°C, stir for 24 hours, and detect by HPLC. The reaction of product C is complete. Cool to 20-25°C, distill off ethanol, water, and excess hydrazine hydrate at a temperature not higher than 5 mmHg, and the distillation temperature is not higher than 45°C. After distillation is complete, a viscous liquid is obtained. Add 100 ml of formic acid, stir at 25-30°C under nitrogen protection for 48 hours, distill off excess formic acid under a vacuum of 10 mmHg, and distill off the water generated by the reaction together with the formic acid, and the distillation temperature is not higher than 45°C. After distillation is complete, add 50 ml of ethanol-water (1:1, volume ratio), reflux for 2 hours, cool to 0°C, and filter to obtain the compound of formula (1). (When R = H, the obtained compound of formula 1 is 8.7 g, with a yield of 50% and a melting point of 228-231°C; when R = CH3, the obtained compound of formula 1 is 11.8 g, with a yield of 65% and a melting point of 181-183°C)

[0029] Example 2

[0030] The compound of formula (1) or its salt obtained in Example 1 is used as an active ingredient, and an inert carrier and an adjuvant are added to prepare a nematicide.

[0031] Inert carrier can be solid carrier or liquid carrier. Solid carrier can be inorganic mineral powder (such as kaolin, etc.), silica (such as diatomaceous earth, etc.), activated carbon, etc., or plastic carrier (such as polyethylene, polypropylene, etc.), or some fertilizers (such as ammonium sulfate, urea, ammonium chloride, etc.), these carriers can be used alone or in combination. Liquid carrier can be alcohol (such as ethanol, ethylene glycol, etc.), aliphatic hydrocarbon (such as kerosene, mineral oil, etc.), ester (such as diisopropyl phthalate, dibutyl phthalate, etc.), amide (such as dimethylformamide, dimethylacetamide, etc.).

[0032] The auxiliary agents may be polyoxyethylene ethers, polyoxyethylene higher fatty acids, alkyl aryl sulfonates, higher alcohol sulfates, etc. The addition of these auxiliary agents can play the role of emulsification, dispersion, dissolution, penetration, etc.

[0033] The nematicide of the present invention can be used directly to control nematodes, or can be used after being diluted with a suitable diluent such as water, or suspended in water.

[0034] Example 3 Test on activity against southern root-knot nematode

[0035] The compound of formula (1) obtained in Example 1 of the present invention and the compound A-89 in the existing patent CN 117479838A were used, and the test was carried out according to NY / T 1833.1-2009 "Guidelines for Indoor Bioassay of Pesticides: Nematicides" Part 1: Inhibition of Plant Pathogenic Nematodes by the immersion method.

[0036] The nematode activity obtained from the test is shown in Table 1 below

[0037] Table 1

[0038]

[0039] As can be seen from Table 1 above, the nematicidal activity of the compound of formula (1) obtained in Example 1 of the present invention is higher than that of the prior art.

[0040] Example 4 Experiment on the activity of inhibiting the hatching of southern root-knot nematode eggs

[0041] The experimental method is as follows:

[0042] To obtain southern root-knot nematode eggs: Wash fresh plant roots infected with root-knot nematodes, cut them into small segments, and surface-sterilize them with a 0.5% NaClO solution for 3 minutes. Place them in a tissue grinder with 5 times the amount of water and grind them for 30-50 seconds. Transfer them to a combination of 75 μm and 26 μm standard sieves, rinse the plant tissue in the sieves with water, collect the nematode eggs in the 500-mesh standard sieve, and dilute them with distilled water to a nematode egg suspension of approximately 400 eggs / mL for later use.

[0043] A certain concentration of drug was added to the nematode egg suspension. After 7 days, the number of hatched and unhatched eggs was checked and the hatching inhibition rate was calculated.

[0044] Hatching rate (%) = number of hatched worms / (number of hatched worms + number of unhatched eggs) × 100%

[0045] Hatching inhibition rate (%) = (hatching rate of control group - hatching rate of treatment group) / hatching rate of control group × 100%

[0046] The agents used in the above experiments are the compound of formula (1) obtained in Example 1 of the present invention and the compound A-89 in the existing patent CN117479838 A. The results of the experiments are shown in Table 2 below.

[0047] Table 2

[0048]

[0049] It can be seen from Table 2 above that at the same concentration, the compound of formula (1) obtained in Example 1 of the present invention has a higher activity in inhibiting the hatching of southern root-knot nematode eggs than the prior art.

[0050] Example 5

[0051] The following experiment was conducted in accordance with the requirements of the Guidelines for Field Efficacy Tests of Pesticides (I): Nematicides for Control of Root Nematodes (GBT17980.38-2000).

[0052] Nematicides: The nematicides of Example 2 of the present invention and the nematicides of the existing patent CN

[0053] The A-89 compound in 117479838A is used as an active ingredient to prepare a nematicide;

[0054] Test crop: sweet potato

[0055] Diseased plant grading method:

[0056] Level 0: No root galls;

[0057] Level 1: There are a few small galls on the roots;

[0058] Level 3: Two-thirds of the root system is covered with small galls;

[0059] Level 5: The root system is covered with small galls and has secondary galls;

[0060] Level 7: The root system forms a fibrous root ball.

[0061] After testing different pesticides, the results are shown in Table 3 below.

[0062] Table 3

[0063]

[0064] As can be seen from Table 3 above, the present invention uses the compound of formula (1) as an active ingredient to prepare a nematicide. At a concentration of 100 ppm, the control effect on sweet potato root nematode disease reaches level 1, while the prior art still reaches level 1 at a concentration of 200 ppm. Therefore, compared with the prior art, the compound of the present invention has higher activity.

Claims

1. A compound or a salt thereof for controlling nematodes, characterized in that: It is represented by the general formula (1), R in formula (1) is hydrogen or methyl.

2. Use of the compound or salt thereof according to claim 1 in controlling nematodes.

3. Use of the compound or salt thereof according to claim 1 in the preparation of a nematicide.

4. A nematicide, characterized in that: Contains the compound or a salt thereof according to claim 1 as an active ingredient.

5. The nematicide according to claim 4, characterized in that: The nematicide further comprises an inert carrier and an adjuvant.

6. A method for controlling nematodes, characterized in that: The compound or a salt thereof according to claim 1 is applied to soil, nematodes, plants or crop seeds.

Images