CN103641782B - Pyrazol acylhydrazone compounds and application thereof - Google Patents

Abstract

The invention discloses pyrazol acylhydrazone compounds with structural formulas shown in a formula I which is shown in the specification. The compounds have insecticidal action and can be used for preventing and treating common agricultural pests.

Description

A kind of pyrazole hydrazone compound and application thereof

Technical field The present invention belongs to the field of agricultural insecticides, and specifically relates to a pyrazole hydrazone compound and its use as an agricultural insecticide.

Background Art Harmful insects harm crops, resulting in reduced yield and quality of crops. Regardless of biological or chemical pesticides, frequent use of large quantities will easily lead to resistance of pests; development of new insecticide varieties, especially the development of new mechanisms of action Insecticide varieties are an effective way to control pest resistance. CN101774951P reports the compound of formula II and its use for controlling pests. Its mechanism of action is different from existing pesticides and can be used to control drug-resistant pests, but the compound has not been commercialized as a pesticide in China; US0053248421A discloses formula III The compound, the trade name of which is "toxenpyramide", has good control effects when used for thrips and tea leafhoppers. However, the synthesis of this compound requires the use of catalytic high-pressure hydrogenation, and its production safety and cost factors lead to its high price, which is difficult to popularize. In the prior art, there is no report on the pyrazole acylhydrazone compound (formula I) and its insecticidal activity as in the present invention.

SUMMARY OF THE INVENTION The object of the present invention is to provide a pyrazoleyl hydrazone agricultural insecticide with novel structure, good insecticidal effect and low control cost.

Technical scheme of the present invention is as follows:

A kind of pyrazole acylhydrazone compound, the structure is as shown in formula I:

Compounds of formula I of the present invention can be prepared by the following reactions:

2-Chloro-4-(4-chlorophenoxy) acetophenone and hydrazine hydrate are reacted in ethanol to obtain compound IV; The compound of the present invention (Formula I) was obtained by reacting at room temperature for 2 h.

The compound of the present invention has a certain similarity with the compound of formula II and formula III in structure, but as an active molecule, the slight difference in structure will affect the permeability of the compound in the organism and the suitability of binding to the target action site, As a result, the biological activity varies widely. In the prior art, the transportability of biologically active molecules in harmful organisms and the suitability for binding to the site of action are unpredictable and require a lot of creative work to know. Tests have proved that the compound of the present invention has unexpected insecticidal effects on pests, such as the activity of diamondback moth is much higher than the commercial insecticide "fenpyran" (compound of formula III), therefore, the present invention also includes the compound of formula I For the purpose of controlling pests.

Advantages and positive effects of the present invention: there are very few commercial varieties of hydrazone insecticides at present, and its insecticidal mechanism is different from other existing types of insecticides, so the compounds of the present invention have good application potential and potential for controlling drug-resistant pests. value. The raw material 2-chloro-4-(4-chlorophenoxy)acetophenone used in the preparation of the compound of the present invention belongs to the intermediate for the production of "difenoconazole", which is produced by many domestic manufacturers; the preparation method of pyrazole chloride is the same as that of " Some of the intermediates of "toxenpyran" (compound of formula III) are similar, and there is no technical problem. Therefore, the compound of the present invention is used as a new type of pesticide, which has the advantages of low resistance, low cost and simple process, and also makes up for the current shortage of hydrazone insecticides, and has very positive significance for the control of resistant pests in my country. .

The present invention also includes a pesticidal composition comprising the compound of formula I as an active ingredient, and the composition further includes an agriculturally acceptable carrier.

The compound of the present invention can be used alone or in combination with other active compounds to improve the comprehensive control function of the product when controlling insect pests.

The composition of the present invention can be administered in the form of preparations. The compound of formula I is dissolved or dispersed in a carrier or solvent as an active component, and an appropriate active agent is added to make emulsifiable concentrate, microemulsion, water emulsion or suspension.

It should be understood that various changes and modifications can be made within the scope of the present invention defined by the claims.

Detailed ways:

The following synthetic examples and bioassay results can be used to further illustrate the present invention, but are not meant to limit the present invention.

synthetic example

The preparation of example 1, formula 1 compound

(1) Synthesis of ethyl 1,1,1-trimethylacetylacetonate

Steps: Add 150mL of absolute ethanol to a 500mL four-neck flask, under nitrogen protection, add 14.64g (0.64mol) of sodium metal in three batches, after the sodium metal in the reaction solution disappears, cool down in an ice-water bath and continue stirring for 20 minutes, slowly drop into the reaction flask Add a mixture of 40.00g (0.46mol) of pinacolone and 66.38g (0.46mol) of diethyl oxalate, drop it for 1 hour, continue to react for 2 hours after the drop, and detect that diethyl oxalate disappears by TLC. Add 37% concentrated hydrochloric acid to adjust the pH value to about 5, distill off the solvent, wash the residue with water and suction filter, the filter cake is the product 1,1,1-trimethylacetylacetonate ethyl ester, after drying, 80.63g white Solid, 88.6% yield.

(2) Synthesis of ethyl 3-tert-butyl-5-pyrazolecarboxylate

Steps: Add 37.47g (0.19mol) ethyl 1,1,1-trimethylacetylacetonate and 120mL glacial acetic acid to a 250mL four-necked flask, and slowly add 14.05g 80% of Hydrazine hydrate (0.23mol) was added dropwise and heated to reflux for 1 hour. TLC detected that the reaction of the raw materials was complete. The temperature was lowered, and the solvent was rotary evaporated. The residue was washed with water and suction filtered to obtain 35.19 g of a white powder solid with a yield of 96.0%.

(3) Synthesis of ethyl 1-methyl-3-tert-butyl-5-pyrazolecarboxylate

Steps: Add 26.00g (0.13mol) ethyl 3-tert-butyl-5-pyrazolecarboxylate and 120mL 1,2-dichloroethane to a 250mL four-neck flask, and slowly drop in 18.39g (0.15mol) under mechanical stirring The dimethyl sulfate was dropped within 0.5h. After the drop, the temperature was raised to reflux for 2h. TLC detected that the raw materials disappeared and the reaction was completed, and the reaction was cooled to room temperature. Add saturated sodium carbonate aqueous solution to adjust the pH value to 7, put the reaction solution in a separatory funnel, separate the water layer, wash the organic layer with 30mL saturated brine, separate the organic layer and add anhydrous sodium sulfate to dry, suction filter, and the filtrate After evaporation to dryness, 24.24 g of ethyl 1-methyl-3-tert-butyl-5-pyrazolecarboxylate was obtained, with a yield of 87.1%.

(4) Synthesis of ethyl 1-methyl-3-tert-butyl-4-chloro-5-pyrazolecarboxylate

Steps: Add 27.86g (0.13mol) ethyl 1-methyl-3-tert-butyl-5-pyrazolecarboxylate into a 250mL four-necked flask, and slowly add 37.90g (0.28mol) ) sulfonyl chloride, after the dropwise addition, the temperature was raised to reflux for 1 h, TLC detected that the raw materials disappeared, the temperature was lowered, the reaction solution was rotary evaporated to remove the solvent and excess sulfonyl chloride, and the oily product 1-methyl-3-tert-butyl-4- Ethyl chloro-5-pyrazolecarboxylate was 30.24g, and the yield was 93.0%.

(5) Synthesis of 1-methyl-3-tert-butyl-4-chloro-5-pyrazolecarboxylic acid

Steps: Add 32.52g (0.13mol) 1-methyl-3-tert-butyl-4-chloro-5-pyrazole ethyl carboxylate into a 250mL four-neck flask, add 14.99g (0.38mol) hydrogen under stirring A 40% aqueous solution made of sodium oxide was added and heated to 40°C, stirred for 4 hours, and the raw material disappeared as detected by TLC. The methanol was rotary evaporated to dryness. After cooling the residue, 50 mL of water was added, and the pH value was adjusted to 3 with 37% hydrochloric acid. Filtered, the filter cake was washed with 20mL of water, and dried to obtain 23.73g of white solid with a yield of 81.4%.

(6) Synthesis of 1-methyl-3-tert-butyl-4-chloro-5-pyrazolecarbonyl chloride

Steps: Add dry 37.07g (0.17mol) 1-methyl-3-tert-butyl-4-chloro-5-pyrazolecarboxylic acid, 150mL toluene and 5 drops of DMF to a 500mL four-neck flask, add 78.20 g (0.66mol) thionyl chloride, warming up and refluxing for 5h, the solution became clear during the reaction process, TLC detected that the raw materials disappeared, lowered the temperature, and removed toluene and excess thionyl chloride by rotary evaporation to obtain 39.21g of light yellow oily liquid, with a yield of 97.8 %.

(7) Synthesis of Intermediate IV

Steps: add 42.16g (0.15mol) of ether ketone and 100mL of absolute ethanol to a 250mL four-way flask, slowly add 37.47g of 80% hydrazine hydrate (0.60mol) dropwise under stirring, heat up and reflux for 4 hours, TLC detects that the raw materials disappear, cool down, The solvent was evaporated by rotary evaporation, and 50 ml of water was added after the residue was lowered to room temperature, and 41.25 g of white powder solid was obtained by suction filtration, with a yield of 93.2%.

(8) Synthesis of compound I

Steps: Add 2.95g (10.00mmol) of intermediate IV, 40mL of acetonitrile and 2.22g (22.00mmol) of triethylamine into a 100mL three-necked flask, cool down in an ice-water bath and continue stirring for 10min, then add 5.64g of 50% (12.00mmol) 1-formazol dropwise Base-3-tert-butyl-4-chloro-5-pyrazolecarbonyl chloride was added, stirred at room temperature for 2 hours, and TLC detected that the reaction was complete. Add 10 mL of saturated NaHCO ₃ aqueous solution, filter with suction, wash the filter cake with 10 mL×2 distilled water, and dry to obtain 4.69 g of white solid, yield 95.1%, melting point: 141-144°C.

The proton nuclear magnetic data of the compound of formula I are as follows:

¹ H NMR (500MHz DMSO): δ/ppm 1.21(s,3H),1.35(s,9H),3.82(s,3H),6.78-7.56(m,8H)

Biotest example

Example 2, the determination of the activity of killing Plutella xylostella

Use the leaf dipping method. The leaf dipping method proposed by the International Resistance Council (IRAC) was used. Use the prepared drug solution to be tested, dip the olive leaves with straight ophthalmic tweezers for 3-5 seconds, shake off the remaining liquid, 1 piece at a time, 3 pieces for each sample, and place them on the processing paper in order of sample marking . After the liquid medicine dries, put it into a marked 10 cm long straight tube, insert 30 2nd instar diamondback moth larvae, and cover the tube mouth with gauze. Place the experimental sample tube in the standard treatment room, check the results after 48 hours, and lightly touch the insect body with a needle, and those who do not move are considered dead. Calculate the mortality rate (the experiment was repeated 3 times, and the average value was taken).

According to the above method, compound I of the present invention is compared with known compound III Plutella xylostella activity in parallel (mortality %), and the results are shown in Table 1:

Table 1 Determination of Plutella xylostella activity

The results of the insecticidal test in Table 1 show that, compared with compound III, compound I of the present invention has a better insecticidal effect on diamondback moth.

Claims (3)

1. A pyrazole acylhydrazone compound, the structure is as shown in formula I: 2. the purposes of pyrazole acylhydrazone compound for agricultural insecticide according to claim 1. 3. A pesticidal composition, comprising the compound of formula I according to claim 1 as an active component and an agriculturally acceptable carrier.