Compound containing oxime ester structure and preparation method and application thereof

Abstract

The invention provides a compound containing an oxime ester structure and a preparation method and application thereof, and belongs to the technical field of compound synthesis. The invention solves the problem that the existing oxime ester PPO inhibitor herbicide cannot have high herbicidal activity, high environmental protection property and use safety at the same time. The preparation method comprises the following steps: taking an extract in rice husk as a raw material, synthesizing an oxime intermediate from the extract and hydroxylamine hydrochloride under an alkaline condition, and reacting the oxime intermediate with acyl chloride in an alkaline environment to synthesize a compound containing an oxime ester structure. The compound containing the oxime ester structure provided by the invention has good inhibition activity on weeds, especially has an excellent effect on dicotyledonous weeds, and the control effect is even superior to that of some commercial herbicides. The compound containing the oxime ester structure provided by the invention has good safety to crops. The compound containing the oxime ester structure provided by the invention can be prepared into a weeding agent to be applied to prevention and control of crop weeds.

Description

Technical Field

[0001] The invention belongs to the technical field of compound synthesis, and in particular relates to a compound containing an oxime ester structure and a preparation method and application thereof. Background Art

[0002] The high efficiency of traditional pesticides has played a significant role in increasing crop yields, but their overuse and abuse have caused multiple problems. For example, weeds have gradually evolved strong resistance to existing pesticides and even cross-resistance after long-term exposure to chemical synthetic pesticides. In addition, traditional pesticides have non-target toxicity, long-term residue problems, and poor biodegradability. Therefore, the development of green and environmentally friendly pesticides has become an urgent task in current agricultural research. Natural products have attracted much attention because they are widely present in nature, easy to obtain, low-cost, and have the characteristics of rapid biodegradation. Natural products are almost non-toxic to the ecological environment, so they have great application potential.

[0003] Rice is an important food crop in the world. Its byproduct rice husk has a huge annual output, but its utilization rate is low and it is often treated as waste, which not only wastes precious resources but also puts pressure on the environment. Studies have found that the ethanol extract of rice husk has biological activity. Through in-depth research on the active substances in rice husk, phenolic compounds with herbicidal activity were isolated, which have an inhibitory effect on the root growth of many weeds. However, the herbicidal activity of natural compounds extracted from rice husk is low, and the herbicidal effect needs to be further improved.

[0004] Protoporphyrin oxidase (PPO) plays a vital role in weed control as a target enzyme for designing safe and effective herbicides. Oxime ester compounds have multiple biological activities. As an important class of PPO inhibitor herbicides, they have a wide spectrum of weed control, high efficiency, low dosage, and are not easy to produce resistance. They have excellent herbicidal activity and stability, but oxime ester herbicides also have many problems. For example, the oxime ester natural herbicides such as myrtle aldehyde oxime ester compounds and osthole oxime ester compounds that have been discovered have advantages such as super high efficiency, low toxicity to mammals, low environmental pollution, and not easy to produce resistance. However, they have the disadvantages of long residual time in the soil, phytotoxicity to subsequent crops, especially cotton, high activity on resistant weeds, little effect on weeds grown after application, and unsuitable for broad-leaved crops, which are not conducive to practical use in agricultural production. Therefore, the development of an oxime ester PPO inhibitor herbicide based on natural compounds is of great significance for finding a highly active and safe lead compound. Summary of the invention

[0005] In order to overcome the above technical defects, the present invention provides a compound containing an oxime ester structure and a preparation method and application thereof.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] One of the purposes of the present invention is to provide a compound containing an oxime ester structure, the general structural formula of the compound is shown in the following formula (I) or formula (II):

[0008]

[0009] The structure of R1 is shown as one of a, b, and c; and R2 is one of H, methyl, and methoxy.

[0010] A second object of the present invention is to provide a method for preparing the above-mentioned compound containing an oxime ester structure, the method comprising:

[0011] Step 1: dissolving sodium acetate, hydroxylamine hydrochloride, and one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde in a solvent for reaction, and immediately pouring the reaction solution into ice water after the reaction is completed to precipitate a white solid, and drying and purifying the white solid to obtain an oxime intermediate;

[0012] Step 2: dissolving the oxime intermediate and the catalyst in a solvent, adding dichloromethane containing an acyl chloride substance, and reacting, and after the reaction is completed, sequentially performing extraction, drying, filtering, evaporation under reduced pressure, and silica gel column treatment to obtain a compound containing an oxime ester structure.

[0013] It is further defined that in step 1, the molar ratio of one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, 3,5-dimethoxy-4-hydroxybenzaldehyde to hydroxylamine hydrochloride is 1:(1.2-2), preferably 1:1.5.

[0014] It is further defined that the solvent in step 1 is a solution composed of water and anhydrous ethanol in a volume ratio of 1:(3-5).

[0015] Further defined, the reaction temperature in step 1 is 80-90°C, preferably 80-85°C.

[0016] It is further defined that the reaction time in step 1 is 4 to 6 hours.

[0017] It is further defined that in step 1, the molar volume ratio of the solvent to one of 3-hydroxy-4-methoxybenzaldehyde, 5-methylsalicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde is (20-30) mL: (10-12) mmol.

[0018] It is further defined that the molar ratio of the oxime intermediate to the acyl chloride substance in step 2 is 1:(1-1.3).

[0019] Further defined, the solvent in step 2 is dichloromethane, N,N-dimethylformamide or tetrahydrofuran, preferably dichloromethane.

[0020] Further limited, the catalyst in step 2 is pyridine, tetramethylethylenediamine or triethylamine, preferably pyridine.

[0021] It is further defined that the reaction temperature in step 2 is 0-5°C.

[0022] The third object of the present invention is to provide a compound containing an oxime ester structure for use as a pesticide in preventing and controlling weeds in crops.

[0023] It is further defined that the weeds are at least one of monocotyledonous weeds or dicotyledonous weeds.

[0024] It is further specified that the weeds are at least one of crabgrass, foxtail grass, barnyard grass, purslane, amaranth, and ramie.

[0025] It is further limited that the crops are rice, peanuts, corn, wheat and cotton.

[0026] A fourth object of the present invention is to provide a compound containing an oxime ester structure for use as an active ingredient in the preparation of herbicidal agents.

[0027] It is further defined that the active ingredient in the formulation is applied at a concentration of 37.5 to 300 g ai / ha.

[0028] The present invention has the following beneficial effects:

[0029] (1) The present invention uses 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde or 3,5-dimethoxy-4-hydroxybenzaldehyde, a natural compound extracted from rice husk, as raw materials to prepare a compound containing an oxime ester structure. The green pesticide is designed and developed using environmentally friendly raw materials as the main raw materials, which can effectively solve the serious drug resistance and persistent residue problems of chemical pesticides. The raw materials are widely available and pollution-free, avoiding chemical pollution caused by preparing herbicides with commercial chemical reagents, and having high environmental protection.

[0030] (2) The compounds containing oxime ester structures provided by the present invention have particularly excellent herbicidal activity against weeds such as purslane, Amaranthus retroflexus, and Abutilon flax.

[0031] (3) The compounds containing oxime ester structures provided by the present invention have good inhibitory activity against protoporphyrin oxidase and high herbicidal activity, especially against dicotyledonous weeds, and the control effect is even better than some commercial herbicides on the market. At the same time, the compounds containing oxime ester structures provided by the present invention have high safety activity against crops while maintaining excellent herbicidal activity.

[0032] (4) The main raw material of the present invention is a phenolic compound separated from natural waste rice husk, which has pharmacological activities such as antibacterial, herbicidal and antioxidant. In addition, this phenolic compound has little impact on human health and the environment. Therefore, molecular structure design is carried out on the basis of the phenolic compound separated from rice husk to synthesize an oxime ester structure compound with herbicidal, insecticidal and antibacterial activities. The oxime ester structure in the compound not only has high herbicidal activity, but also is more easily metabolized in the environment, and has less pollution to the environment and human body. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0036] The synthetic route of the compound containing oxime ester structure provided by the present invention is as follows:

[0037]

[0038] Example 1 Preparation of (E)-3-hydroxy-4-methoxybenzaldehyde O-benzoyl oxime

[0039] Step 1: Preparation of (E)-3-hydroxy-4-methoxybenzaldehyde oxime

[0040] 10.0 mmol 3-hydroxy-4-methoxybenzaldehyde, 15.0 mmol hydroxylamine hydrochloride, 20.0 mmol sodium acetate (to provide an alkaline environment), 5 mL water and 15 mL anhydrous ethanol were added to a 250 mL round-bottom flask, the temperature was raised to 80°C, and the mixture was stirred for reaction for 5 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the reaction solution was quickly poured into 50 mL ice water. After a white solid was precipitated, the white solid was dried at 45°C for 6 h to obtain a crude product. The crude product was purified by recrystallization using petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate was 1:(3-5) to obtain a white solid oxime intermediate a1.

[0041] The structural formula of oxime intermediate a1 is:

[0042] Step 2: Preparation of (E)-3-hydroxy-4-methoxybenzaldehyde O-benzoyl oxime

[0043] 5.0mmol oxime intermediate a1, 5mmol pyridine (as a base catalyst) and 10mL dichloromethane were added to a 250mL round-bottom flask. The reaction system was turbid. After stirring under ice bath conditions (0-5°C), 10mL dichloromethane containing 6.0mmol benzoyl chloride was added dropwise. The reaction was carried out under ice bath conditions (0-5°C). Thin layer chromatography (TLC) was used to monitor the progress of the reaction. The reaction was carried out under ice bath conditions (0-5°C) until the reaction was completed (the reaction solution was clear and transparent when the reaction was completed). The reaction time was 3-4h. 50mL distilled water was added and extracted with dichloromethane. The organic phases were combined and dried with anhydrous Na2SO4, followed by filtration and reduced pressure evaporation. Then, pure (E)-3-hydroxy-4-methoxybenzaldehyde O-benzoyl oxime was obtained by silica gel column treatment. The product yield was 86%.

[0044] The product test data are as follows: mp: 122.3-122.8°C; 1 H NMR (600MHz, CDCl3): δ3.96 (3H, s), 6.89 (1H, dd, J=8.44, 0.46Hz), 7.26 (1H, dd, J=1.72, 0.46Hz), 7.44-7.59 (4H, 7.49 (dddd, J=8.18, 7.49, 1.32, 0.45Hz), 7.62 (dd, J=8.44, 1.72Hz), 7.89 (tt, J=7.50, 1.43Hz), 8.16 (2H, dddd, J=8.48, 1.85, 1.43, 0.45Hz), 8.17 (1H, s). 13C NMR (151 MHz, CDCl3): δ 56.16, 104.56, 110.84, 117.67, 119.06, 125.65, 127.58, 128.90, 130.08, 134.35, 145.96, 150.31, 156.54. HRMS, 272.0494 / 272.0490 (+source).

[0045] Example 2 Preparation of (E)-3-hydroxy-4-methoxybenzaldehyde O-(3-methylbenzoyl)oxime

[0046] The difference between this embodiment and embodiment 1 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol 3-methylbenzoyl chloride, and the final product is (E)-3-hydroxy-4-methoxybenzaldehyde O-(3-methylbenzoyl) oxime, which has the same steps and process parameters, and the product yield is 87%.

[0047] The product detection data are as follows: mp: 87%; mp111.5-112.7℃; 1 H NMR (600MHz, CDCl3): δ2.36 (3H, s), 3.86 (3H, s), 6.90 (1H, dd, J=8.44, 0.46Hz), 7.08 (1H, dd, J = 1.72, 0.46Hz), 7.20-7.38 (3H, 7.20 (ddd, J = 7.89, 1.28, 1.08Hz) , 7.21 (ddd, J=8.52, 7.89, 0.44Hz), 7.32 (dd, J=8.44, 1.72Hz), 7.94-7.98 (2H, 8 .00 (ddd, J=1.55, 1.28, 0.44Hz), 8.05 (ddd, J=8.52, 1.55, 1.08Hz), 8.52 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 22.20, 56.88, 108.06, 111.43, 114.39, 120.06, 124.41, 128.03, 130.24, 132.32, 136.13, 136.63, 145.69, 146.64, 147.29, 148.67. HRMS, 286.1077 / 286.1071 (+ source).

[0048] Example 3 Preparation of (E)-3-hydroxy-4-methoxybenzaldehyde O-(2-methoxybenzoyl)oxime

[0049] The difference between this embodiment and embodiment 1 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol of 2-methoxybenzoyl chloride, and the final product is pure (E)-3-hydroxy-4-methoxybenzaldehyde O-(2-methoxybenzoyl) oxime, which has the same steps and process parameters, and the product yield is 89%.

[0050] The product test data are as follows: mp: 102.9-103.1°C; 1 H NMR (600MHz, CDCl3): 3.84 (3H, s), 3.87 (3H, s), 6.76 (1H, dd, J=8.44, 0.46Hz ), 7.12 (1H, ddd, J = 8.33, 1.24, 0.47Hz), 7.27 (1H, ddd, J = 8.08, 7.35, 1.24Hz) ), 7.26 (1H, dd, J = 1.72, 0.46Hz), 7.52 (1H, dd, J = 8.44, 1.72Hz), 7.69 (1H, dd d, J=8.33, 7.35, 1.45Hz), 7.91 (1H, ddd, J=8.08, 1.45, 0.47Hz), 8.92 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 56.15, 56.70, 56.00, 104.58, 110.83, 111.65, 117.60, 117.64, 119.07, 122.26, 125.62, 133.85, 135.12, 145.98, 150.30, 158.05, 165.41. HRMS, 302.9519 / 302.9529 (+source).

[0051] Example 4 Preparation of (E)-3-hydroxy-4-methoxybenzaldehyde O-furan-2-carbonyl oxime

[0052] The difference between this embodiment and embodiment 1 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol of furancarbonyl chloride, and the final product is pure (E)-3-hydroxy-4-methoxybenzaldehyde O-furan-2-carbonyl oxime, which has the same steps and process parameters, and the product yield is 80%.

[0053] The product test data are as follows: mp: 142.6-143.8°C; 1H NMR (600MHz, CDCl3): δ3.84 (3H, s), 6.66 (1H, dd, J=3.37, 1.75Hz), 6.76 (1H, dd, J=8.44, 0.46Hz), 7.26 (1H, dd, J=1.7 2, 0.46Hz), 7.33 (1H, dd, J = 3.37, 0.88Hz), 7.52 (1H, dd, J = 8.44, 1.72Hz), 7.91 (1H, dd, J = 1.75, 0.88Hz), 8.93 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 56.60, 102.34, 105.60, 106.74, 109.20, 112.28, 119.34, 120.06, 139.31, 143.80, 147.19, 147.39, 162.92. HRMS, 262.0746 / 262.0740 (+source).

[0054] Example 5 Preparation of (E)-2-Hydroxy-5-methylbenzaldehyde O-benzoyl oxime

[0055] Step 1: Preparation of (E)-2-hydroxy-5-methylbenzaldehyde oxime

[0056] 10.0 mmol 5-methyl salicylaldehyde, 15.0 mmol hydroxylamine hydrochloride, 20.0 mmol sodium acetate (to provide an alkaline environment), 5 mL water and 15 mL anhydrous ethanol were added to a 250 mL round-bottom flask, the temperature was raised to 80° C., and the mixture was stirred for reaction for 5 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the reaction solution was quickly poured into 50 mL ice water. After a white solid was precipitated, the white solid was dried to obtain a crude product. The crude product was purified by recrystallization using petroleum ether and ethyl acetate to obtain a white solid oxime intermediate b1.

[0057] The structural formula of oxime intermediate b1 is:

[0058] Step 2: Preparation of (E)-2-hydroxy-5-methylbenzaldehyde O-benzoyl oxime

[0059] 5.0 mmol oxime intermediate b1, 5 mmol pyridine (as a base catalyst) and 10 mL dichloromethane were added to a 250 mL round-bottom flask. The reaction system was turbid. After stirring under ice bath conditions (0-5°C), 10 mL dichloromethane containing 6.0 mmol benzoyl chloride was added dropwise. The reaction progress was monitored by thin layer chromatography (TLC). The reaction was continued under ice bath conditions (0-5°C) until the reaction was completed (the reaction solution was clear and transparent when the reaction was completed). The reaction time was 3-4 h. 50 mL distilled water was added and extracted with dichloromethane. The organic phases were combined and dried with anhydrous Na2SO4, followed by filtration and reduced pressure evaporation. Then, the mixture was treated with a silica gel column to obtain pure (E)-2-hydroxy-5-methylbenzaldehyde O-benzoyl oxime. The product yield was 84%.

[0060] The product test data are as follows: mp: 127.0-127.8°C; 1 H NMR (600MHz, CDCl3): δ2.31 (3H, s), 6.82 (1H, dd, J=8.38, 0.46Hz), 7.14 (1H, dd, J=8.38, 1.83Hz), 7.40-7.66 (4H, 7.45 (dd, J=1.83, 0. 46Hz), 7.49 (dddd, J=8.48, 7.50, 1.32, 0.45Hz), 7.60 (tt, J=7.50, 1.43Hz), 8.06 (2H, dddd, J=8.48, 1.85, 1.43, 0.45Hz), 9.71 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 20.27, 114.55, 117.33, 128.02, 128.69, 128.99, 129.78, 131.94, 133.71, 134.18, 156.35, 157.97, 163.02. HRMS, 256.0972 / 256.0964 (+ source).

[0061] Example 6 Preparation of (E)-2-hydroxy-5-methylbenzaldehyde O-(3-methylbenzoyl)oxime

[0062] The difference between this embodiment and embodiment 7 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol 3-methylbenzoyl chloride, and the final product is pure (E)-2-hydroxy-5-methylbenzaldehyde O-(3-methylbenzoyl) oxime, which has the same steps and process parameters, and the product yield is 82%.

[0063] The product test data are as follows: mp: 142.2-142.9°C; 1H NMR (600MHz, CDCl3): δ2.32 (3H, s), 2.44 (3H, s), 6.82 (1H, dd, J=8.38, 0.46H z), 7.14 (1H, dd, J = 8.38, 1.83Hz), 7.39 (1H, ddd, J = 7.89, 1.28, 1.08Hz), 7.45 (1H, dd, J = 1.83, 0.46Hz), 7.51 (1H, ddd, J = 8.52, 7.89, 0.44Hz), 7.95 (1H, ddd , J=1.55, 1.28, 0.44Hz), 8.60 (1H, ddd, J=8.52, 1.55, 1.08Hz), 10.12 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 16.84, 21.30, 114.26, 119.38, 126.68, 126.89, 127.91, 128.54, 129.72, 130.30, 134.46, 138.54, 156.73, 158.02, 163.12, 170.37. HRMS, 270.1129 / 270.1126 (+source).

[0064] Example 7 Preparation of (E)-2-hydroxy-5-methylbenzaldehyde O-(2-methoxybenzoyl)oxime

[0065] The difference between this embodiment and embodiment 7 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol of 2-methoxybenzoyl chloride, and the final product is pure (E)-2-hydroxy-5-methylbenzaldehyde O-(2-methoxybenzoyl) oxime, which has the same steps and process parameters, and the product yield is 84%.

[0066] The product test data are as follows: mp: 162.8-164.3°C; 1 H NMR (600MHz, CDCl3): δ2.28 (3H, s), 3.89 (3H, s), 6.82 (1H, dd, J=8.38, 0.46H z), 7.12 (1H, dd, J = 8.33, 1.24, 0.47Hz), 7.14 (1H, dd, J = 8.38, 1.83Hz), 7.27 (1H, ddd, J = 8.08, 7.35, 1.24Hz), 7.45 (1H, dd, J = 1.83, 0.46Hz), 7.86 (1H, ddd , J=8.33, 7.35, 1.45Hz), 8.54 (1H, ddd, J=8.08, 1.45, 0.47Hz), 10.13 (1H, s). 13C NMR (151 MHz, CDCl3): δ 16.86, 56.04, 114.37, 117.90, 119.33, 120.31, 126.64, 129.72, 131.60, 134.21, 134.26, 135.13, 156.73, 157.93, 159.35, 162.84. HRMS, 286.1077 / 286.1070 (+source).

[0067] Example 8 Preparation of (E)-2-Hydroxy-5-methylbenzaldehyde O-furan-2-carbonyl oxime

[0068] The difference between this embodiment and embodiment 7 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol of furancarbonyl chloride, and the final product is pure (E)-2-hydroxy-5-methylbenzaldehyde O-furan-2-carbonyl oxime, which has the same steps and process parameters, and the product yield is 87%.

[0069] The product test data are as follows: mp: 131.6-133.2°C; 1 H NMR (600MHz, CDCl3): δ2.36 (3H, s), 6.66 (1H, dd, J=3.37, 1.75Hz), 6.82 (1H, dd, J=8.38, 0.46Hz), 7.14 (1H, dd, J=8.38 , 1.83Hz), 7.33 (1H, dd, J = 3.37, 0.88Hz), 7.45 (1H, dd, J = 1.83, 0.46Hz), 7.81 (1H, dd, J = 1.75, 0.88Hz), 10.89 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 15.81, 112.22, 118.11, 119.51, 120.34, 126.65, 129.84, 134.48, 142.31, 146.31, 147.28, 156.61, 158.34. HRMS, 246.0766 / 246.0758 (+ source).

[0070] Example 9 Preparation of (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-benzoyl oxime

[0071] Step 1: Preparation of (E)-4-hydroxy-3,5-dimethoxybenzaldehyde oxime

[0072] 10.0 mmol 3,5-dimethoxy-4-hydroxybenzaldehyde, 15.0 mmol hydroxylamine hydrochloride, 20.0 mmol sodium acetate (to provide an alkaline environment), 5 mL water and 15 mL anhydrous ethanol were added to a 250 mL round-bottom flask, the temperature was raised to 80° C., and the mixture was stirred for reaction for 5 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the reaction solution was quickly poured into 50 mL ice water. After a white solid was precipitated, the white solid was dried to obtain a crude product. The crude product was purified to obtain a white solid oxime intermediate c1.

[0073] The structural formula of oxime intermediate c1 is:

[0074] Step 2: Preparation of (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-benzoyl oxime

[0075] 5.0mmol oxime intermediate c1, 5mmol pyridine (as a base catalyst) and 10mL dichloromethane were added to a 250mL round-bottom flask. The reaction system was turbid. After stirring under ice bath conditions (0-5°C), 10mL dichloromethane containing 6.0mmol benzoyl chloride was added dropwise. The reaction progress was monitored by thin layer chromatography (TLC). The reaction was continued under ice bath conditions (0-5°C) until the reaction was completed (the reaction solution was clear and transparent when the reaction was completed). The reaction time was 3-4h. 50mL distilled water was added and extracted with dichloromethane. The organic phases were combined and dried with anhydrous Na2SO4, followed by filtration and reduced pressure evaporation. Then, pure (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-benzoyl oxime was obtained by silica gel column treatment. The product yield was 80%.

[0076] The product test data are as follows: mp: 152.3-152.8°C; 1 H NMR (600MHz, CDCl3): δ3.86 (6H, s), 7.01 (2H, d, J=1.95Hz), 7.43-7.66 (3H, 7.49 (dddd, J=8.48, 7.50, 1.32, 0.45Hz), 7.60 (tt, J=7.50, 1.43Hz), 7.95 (2H, dddd, J=8.48, 1.85, 1.43, 0.45Hz), 8.05 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 56.60, 109.23, 111.67, 119.37, 122.21, 133.79, 135.09, 139.41, 147.24, 158.09, 165.47. HRMS, 302.1024 / 302.1019 (+ source).

[0077] Example 10 Preparation of (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-(3-methylbenzoyl)oxime

[0078] The difference between this embodiment and embodiment 10 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol 3-methylbenzoyl chloride, and the final product is pure (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-(3-methylbenzoyl) oxime, which has the same steps and process parameters, and the product yield is 76%.

[0079] The product test data are as follows: mp: 112.8-113.9°C; 1 H NMR (600MHz, CDCl3): δ2.44 (3H, s), 3.87 (6H, s), 6.51 (2H, d, J=1.95Hz), 7.33-7.57 (2H, 7.39 (ddd, J=7.89, 1.28, 1.08Hz), 7.51 (ddd, J=8.52, 7.89, 0.44Hz), 7.94-8.08 (2H, 8.00 (ddd, J=1.55, 1.28, 0.44Hz), 8.02 (ddd, J=8.52, 1.55, 1.08Hz), 8.55 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 21.30, 56.50, 109.10, 105.27, 106.53, 127.67, 128.47, 130.30, 130.94, 134.40, 138.50, 152.89, 156.57, 164.20. HRMS, 316.1167 / 316.1160 (+ source).

[0080] Example 11 Preparation of (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-(2-methoxyphenylformyl)oxime

[0081] The difference between this embodiment and embodiment 10 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol of 2-methoxybenzoyl chloride, and the final product is pure (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-(2-methoxyphenylformyl)oxime, which has the same steps and process parameters, and the product yield is 82%.

[0082] The product test data are as follows: mp: 107.2-109.0°C; 1H NMR (600MHz, CDCl3): δ3.91 (3H, s), 3.93 (3H, s), 6.80 (2H, d, J=1.95Hz), 6.92 (1H, ddd, J=8.33, 1.24, 0.47Hz), 7.07 (1H , ddd, J=8.08, 7.35, 1.24Hz), 7.29 (1H, ddd, J=8.33, 7.35, 1.45Hz), 7.51 (1H, ddd, J=8.08, 1.45, 0.47Hz), 8.18 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 56.60, 56.70, 102.31, 109.21, 111.63, 117.69, 119.36, 122.27, 133.85, 136.11, 139.35, 147.21, 158.04, 166.38. HRMS, 332.1128 / 332.1120 (+ source).

[0083] Example 12 Preparation of (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-furan-2-carbonyl oxime

[0084] The difference between this embodiment and embodiment 10 is that the solution added dropwise in step 2 is 10 mL of dichloromethane containing 6.0 mmol of furancarbonyl chloride, and the final product is pure (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-furan-2-carbonyl oxime, which has the same steps and process parameters, and the product yield is 83%.

[0085] The product test data are as follows: mp: 123.4-124.1°C; 1 H NMR (600MHz, CDCl3): δ3.91 (6H, s), 5.96 (1H, dd, J=3.37, 1.75Hz), 6.81 (2H, d, J=1 .95Hz), 7.33 (1H, dd, J=3.37, 0.88Hz), 7.61 (1H, dd, J=1.75, 0.88Hz), 7.95 (1H, s). 13 C NMR (151 MHz, CDCl3): δ 56.26, 103.01, 112.59, 119.52, 126.83, 137.71, 141.85, 147.22, 149.79, 152.31, 156.61. HRMS, 290.0823 / 290.0820 (+ source).

[0086] The general formula of the compounds containing oxime ester structure synthesized in Examples 1 to 12 is shown in Formula I or Formula II:

[0087]

[0088] The structure of R1 is shown as one of a, b, and c; and R2 is one of H, methyl, and methoxy.

[0089] The specific groups in the compounds containing oxime ester structures synthesized in Examples 1 to 12 are shown in Table 1.

[0090] Table 1 Groups in the compounds containing oxime ester structures synthesized in Examples 1 to 12

[0091]

[0092]

[0093] Application Example 1 Herbicidal Activity Experiment

[0094] The compounds containing oxime ester structure prepared in Examples 1 to 12 were subjected to a herbicidal activity assay. Test targets: monocotyledonous weeds: Setaria viridis, barnyard grass and crabgrass, dicotyledonous weeds: Portulaca oleracea, Ramulus flavoides and Amaranthus retroflexus, and the commercial PPO inhibitor oxyfluorfen was selected as the positive control group. When the weeds grew to the two-leaf stage, different concentrations of target compounds were prepared and sprayed on the weed leaves, and the growth status of the weeds was visually evaluated. Most weed plants began to show symptoms such as burns, curling and yellowing one day after spraying, and bleaching and death occurred after 2 to 3 days. The greenhouse herbicidal activity effects of all compounds were expressed as inhibition percentages, and the test results are shown in Table 2;

[0095] The preparation process is as follows: 10 mg of the compound prepared in the example is weighed and dissolved in N, N-dimethylformamide (DMF), Tween-80 is added as an emulsifier, and then distilled water is added to dilute to 10 mL to prepare a stock solution with a concentration of 1 g / L. When spraying, a proper amount of the stock solution is transferred with a pipette and diluted with distilled water to make the application amount 300, 150, 75, and 37.5 g ai / ha, respectively. Table 2 Greenhouse herbicidal activity test results of the compounds containing oxime ester structures prepared in Examples 1 to 12 and the commercial PPO inhibitor oxyfluorfen

[0096]

[0097]

[0098] Note: Grading scale of herbicidal activity (inhibition percentage): ++++, ≥90%; +++, 80-89%; ++, 60-79%; +, 50-59%; -, <50%.

[0099] From the data in Table 2, it can be seen that most of the compounds synthesized in Examples 1 to 12 have better inhibitory activity against dicotyledonous weeds than monocotyledonous weeds; among dicotyledonous weeds, the inhibitory activity of the target compound against Portulaca oleracea is slightly higher than that against Abutilon and Amaranthus retroflexus. Most of the target compounds showed more than 80% inhibitory activity against weeds at an application dose of 300 g ai / ha. The compounds containing oxime ester structure prepared in Examples 4, 8 and 12 showed excellent herbicidal activity, with an inhibition rate of nearly 100% against six weeds at a dose of 300 g ai / ha. The compound prepared in Example 12 had an inhibitory activity against most weeds of more than 80% even at a low dose of 37.5 g ai / ha, and had excellent greenhouse herbicidal activity, which was comparable to or slightly better than the commercial PPO inhibitor oxyfluorfen.

[0100] Application Example 2 Safety Experiment

[0101] The safety test of the compound containing oxime ester structure prepared in Example 12 was carried out. Test targets: rice, peanut, corn, wheat and cotton.

[0102] The test method is the greenhouse cup method: take a certain amount of soil that has passed through a 5mm sieve, soak the selected crop seeds in warm water for 12 hours, and place them in a 25°C incubator for germination for 24 hours. Select 8 uniform and well-germinated crop seeds, evenly place them on the soil surface, with the navel facing down, and cover them with about 10g of dry soil. Under the conditions of temperature 26.5°C and humidity 75%, cycle the light and dark for 12 hours each. When the crops grow to the three-leaf stage, spray the compounds prepared in Example 12 at a dose of 75-300g ai / ha on the leaves of the five crops, and regularly observe the leaf damage and growth of the plants. Within 2 weeks after spraying, the crop safety of the compound was finally evaluated by naked eye observation. Oxyfluorfen was used as the control agent, and each group of experiments was repeated 3 times.

[0103] Table 3 Safety of the compounds containing oxime ester structure prepared in Example 12 and the commercial PPO inhibitor oxyfluorfen to post-emergence crops

[0104]

[0105] It can be seen from the test data in Table 3 that the compound containing an oxime ester structure prepared in Example 12 can be used as a herbicide. When the application dosage is 300 g ai / ha, rice, corn, peanut and wheat show high tolerance to the compound. In addition, the compound containing an oxime ester structure prepared in Example 12 is selective for rice, corn, peanut and wheat, while the commercial PPO inhibitor oxyfluorfen is only selective for rice, corn and wheat, indicating that the safety of the compound prepared in Example 12 is higher than that of the commercial PPO inhibitor oxyfluorfen at the same dosage.

[0106] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A compound containing an oxime ester structure, characterized in that: The general structural formula of the compound is shown in Formula I or Formula II: The structure of R1 is shown as one of a, b, and c; and R2 is one of H, methyl, and methoxy.

2. A method for preparing a compound containing an oxime ester structure, characterized in that: include: Step 1: dissolving sodium acetate, hydroxylamine hydrochloride, and one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde in a solvent for reaction, and immediately pouring the reaction solution into ice water after the reaction is completed to precipitate a white solid, and drying and purifying the white solid to obtain an oxime intermediate; Step 2: dissolving the oxime intermediate and the catalyst in a solvent, adding dichloromethane containing an acyl chloride substance, and reacting, and after the reaction is completed, sequentially performing extraction, drying, filtering, evaporation under reduced pressure, and silica gel column treatment to obtain a compound containing an oxime ester structure.

3. The preparation method according to claim 2, characterized in that: In step 1, the molar ratio of one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, 3,5-dimethoxy-4-hydroxybenzaldehyde and hydroxylamine hydrochloride is 1:(1.2-2).

4. The preparation method according to claim 2, characterized in that: In step 1, the reaction temperature is 80-90° C., the reaction time is 4-6 hours, and the solvent is a solution composed of water and anhydrous ethanol in a volume ratio of 1:(3-5).

5. The preparation method according to claim 2, characterized in that: In step 2, the molar ratio of the oxime intermediate to the acyl chloride substance is 1:(1-1.3); the solvent is dichloromethane, N,N-dimethylformamide or tetrahydrofuran; and the catalyst is pyridine, tetramethylethylenediamine or triethylamine.

6. The preparation method according to claim 2, characterized in that: The reaction temperature in step 2 is 0-5°C.

7. Use of the compound containing an oxime ester structure according to claim 1 as a pesticide in preventing and controlling weeds in crops.

8. The use according to claim 7, characterized in that: The weeds are at least one of monocotyledonous weeds and dicotyledonous weeds.

9. Use of the compound containing an oxime ester structure according to claim 1 as an active ingredient in the preparation of a herbicide.

10. The use according to claim 9, characterized in that: The application concentration of the compound containing oxime ester structure in the pesticide is 37.5-300g ai / ha.

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