A compound containing an oxime ester structure, its preparation method and application

Abstract

This invention provides a compound containing an oxime ester structure, its preparation method, and its application, belonging to the field of compound synthesis technology. This invention solves the problem that existing oxime ester-based PPO inhibitor herbicides cannot simultaneously possess high herbicidal activity, high environmental friendliness, and safe use. This invention uses an extract from rice husks as a raw material, synthesizing an oxime intermediate with hydroxylamine hydrochloride under alkaline conditions. The oxime intermediate is then reacted with an acyl chloride in an alkaline environment to synthesize a compound containing an oxime ester structure. The compound containing an oxime ester structure provided by this invention exhibits good inhibitory activity against weeds, especially dicotyledonous weeds, with control effects even superior to some commercial herbicides. The compound containing an oxime ester structure provided by this invention has good safety for crops. The compound containing an oxime ester structure provided by this invention can be prepared into a herbicidal agent for the control of crop weeds.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of compound synthesis, and particularly relates to a compound containing an oxime ester structure and a preparation method and application thereof. BACKGROUND

[0002] The high efficiency of traditional pesticides plays a significant role in improving crop yields, but their overuse and misuse have caused multiple problems. For example, weeds gradually evolve strong resistance to existing pesticides after long-term exposure to chemically synthesized pesticides, and even cross-resistance occurs. In addition, traditional pesticides have non-target toxicity, long-term residue problems, and difficult biodegradation characteristics. Therefore, developing green and environmentally friendly pesticides has become an urgent task for current agricultural research. Natural products are widely concerned due to their wide existence in nature, easy accessibility, low price, and fast biodegradation characteristics. Moreover, natural products are almost non-toxic to the ecological environment, and thus have great application potential.

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

[0004] Protoporphyrinogen oxidase (PPO) as a target enzyme for designing safe and effective herbicides plays a crucial role in weed control. Oxime ester compounds have various biological activities, and as an important PPO inhibitor herbicide, they have a wide herbicidal spectrum, high efficiency, low dosage, and are not easy to produce resistance, and have excellent herbicidal activity and stability. However, oxime ester herbicides also have many problems. For example, the myrtenal oxime ester compound and the cnidimide oxime ester compound have the advantages of ultra-high efficiency, low toxicity to mammals, small environmental pollution, and difficulty in producing resistance, but they have the disadvantages of long soil residue time, phytotoxicity to post-crop crops, especially cotton, high activity of resistant weeds, little effect on weeds growing after application, and unsuitability for broadleaf crops, which are not conducive to agricultural production. Therefore, developing an oxime ester PPO inhibitor herbicide based on natural compounds is of great significance for finding lead compounds with high activity and high safety. SUMMARY

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

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

[0007] One of the objects of the present application is to provide a compound containing hydroxamic ester structure, the structure of the compound is shown in the following formula (I) or formula (II):

[0008]

[0009] In the formula, the structure of R1 is shown in one of a, b, and c; R2 is one of H, methyl, and methoxy.

[0010] The second object of the present application is to provide a preparation method of the compound containing hydroxamic ester structure, the method comprises the following steps:

[0011] Step one: sodium acetate, hydroxylamine hydrochloride, and one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde are dissolved in a solvent to react, after the reaction is completed, the reaction solution is immediately poured into ice water to precipitate white solids, and the white solids are dried and purified to obtain an oxime intermediate;

[0012] Step two: the oxime intermediate and a catalyst are dissolved in a solvent, dichloromethane containing acyl chloride is added, and then reacted, after the reaction is completed, extraction, drying, filtration, reduced pressure evaporation, and silica gel column treatment are sequentially performed to obtain the compound containing hydroxamic ester structure.

[0013] Further limitation, in step one, the molar ratio of one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde to hydroxylamine hydrochloride is 1:(1.2-2). Preferably, it is 1:1.5.

[0014] Further limitation, in step one, the solvent is a solution composed of water and anhydrous ethanol in a volume ratio of 1:(3-5).

[0015] Further limitation, in step one, the reaction temperature is 80-90°C. Preferably, it is 80-85°C.

[0016] Further limitation, in step one, the reaction time is 4-6h.

[0017] Further limitation, in step one, the volume ratio of the solvent to the amount of one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde is (20-30)mL:(10-12)mmol.

[0018] Further limitation, in step two, the molar ratio of the oxime intermediate to the acyl chloride is 1:(1-1.3).

[0019] Further, the solvent in step two is dichloromethane, N,N-dimethylformamide or tetrahydrofuran. Preferably, the solvent is dichloromethane.

[0020] Further, the catalyst in step two is pyridine, tetramethylethylenediamine or triethylamine. Preferably, the catalyst is pyridine.

[0021] Further, the reaction temperature in step two is 0-5℃.

[0022] The third object of the present application is to provide an application of the compound containing hydroxamic ester structure as a pesticide in controlling weeds in crops.

[0023] Further, the weeds are at least one of monocotyledonous weeds or dicotyledonous weeds.

[0024] Further, the weeds are at least one of Digitaria sanguinalis, Setaria viridis, Echinochloa crus-galli, Portulaca oleracea, Amaranthus retroflexus and Abutilon theophrasti.

[0025] Further, the crops are rice, peanut, corn, wheat and cotton.

[0026] The fourth object of the present application is to provide an application of the compound containing hydroxamic ester structure as an active ingredient in preparing a weed control agent.

[0027] Further, the concentration of the active ingredient in the agent is 37.5-300 g ai / ha.

[0028] The present application has the following advantages:

[0029] (1) The present application uses natural compounds 3-hydroxy-4-methoxybenzaldehyde, 5-methylsalicylaldehyde or 3,5-dimethoxy-4-hydroxybenzaldehyde extracted from rice husks as raw materials to prepare a compound containing hydroxamic ester structure. The environment-friendly raw materials are used as main raw materials to design and develop green pesticides, which can effectively solve the serious pesticide resistance and persistent residue problems of chemical pesticides. The raw materials are widely sourced and pollution-free, avoiding chemical pollution caused by the preparation of herbicides with commercial chemical reagents, and having high environmental protection.

[0030] (2) The compound containing hydroxamic ester structure provided by the present application has particularly excellent herbicidal activity on weeds such as Portulaca oleracea, Amaranthus retroflexus and Abutilon theophrasti.

[0031] (3) The compound containing hydroxamic ester structure provided by the present application has good inhibitory activity on protoporphyrinogen oxidase, high herbicidal activity, and excellent effect on dicotyledonous weeds, and the control effect is even better than some commercial herbicides. At the same time, the compound containing hydroxamic ester structure provided by the present application has high safety activity on crops while maintaining excellent herbicidal activity.

[0032] (4) The main raw material of the present application is a phenolic compound separated from natural waste rice husk, which has antibacterial, herbicidal and antioxidant pharmacological activities. In addition, the phenolic compound has less impact on human health and the environment. Therefore, based on the phenolic compound separated from rice husk, a molecular structure design is carried out to synthesize an oxime ester structure-containing 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 objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the description. In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0034] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. In this specification, "in one embodiment" does not mean the same embodiment, nor is it an independent or alternative embodiment that excludes 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 by commercial channels by those skilled in the art.

[0036] The synthesis route of the oxime ester structure-containing compound provided by the present application is as follows:

[0037]

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

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

[0040] Into a 250 mL round bottom flask, 10.0 mmol of 3-hydroxy-4-methoxybenzaldehyde, 15.0 mmol of hydroxylamine hydrochloride, 20.0 mmol of sodium acetate (to provide a basic environment), 5 mL of water and 15 mL of absolute ethanol were added, the reaction was stirred at 80 °C for 5 h, the progress of the reaction was monitored by thin layer chromatography (TLC), after the reaction was completed, the reaction solution was quickly poured into 50 mL of ice water, 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 with petroleum ether and ethyl acetate, the volume ratio of petroleum ether to ethyl acetate was 1: (3-5), and a white solid of the oxime intermediate a1 was obtained;

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

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

[0043] Into a 250 mL round bottom flask, 5.0 mmol of the oxime intermediate a1, 5 mmol of pyridine (as a basic catalyst) and 10 mL of dichloromethane were added, the reaction system was turbid, after stirring under ice bath conditions (0-5 °C), 6.0 mmol of benzoyl chloride in 10 mL of dichloromethane was added dropwise, the reaction was carried out under ice bath conditions (0-5 °C), the progress of the reaction was monitored by thin layer chromatography (TLC), until the reaction was completed (the reaction solution was clear and transparent at the time of reaction completion), the reaction time was 3-4 h, 50 mL of distilled water was added and extracted with dichloromethane, the organic phases were combined and dried with anhydrous Na2SO4, then filtered and evaporated under reduced pressure, and then treated with a silica gel column to obtain pure (E)-3-hydroxy-4-methoxybenzaldehyde O-benzoyl oxime, the yield of the product was 86%.

[0044] The product detection data are as follows: m.p: 122.3-122.8 °C; 1 H NMR (600 MHz, CDCl3): δ 3.96 (3H, s), 6.89 (1H, dd, J = 8.44, 0.46 Hz), 7.26 (1H, dd, J = 1.72, 0.46 Hz), 7.44-7.59 (4H, 7.49 (dddd, J = 8.18, 7.49, 1.32, 0.45 Hz), 7.62 (dd, J = 8.44, 1.72 Hz), 7.89 (tt, J = 7.50, 1.43 Hz), 8.16 (2H, dddd, J = 8.48, 1.85, 1.43, 0.45 Hz), 8.17 (1H, s). 13C NMR (151 MHz, CDC13): 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] This example differs from Example 1 in that the solution added dropwise in Step two was 10 mL of dichloromethane containing 6.0 mmol of 3-methylbenzoyl chloride and the final product was (E)-3-hydroxy-4-methoxybenzaldehyde O-(3-methylbenzoyl) oxime which was isolated in 87% yield.

[0047] Product testing data are as follows: m.p: 87%; m.p. 111.5-112.7 °C; 1 H NMR (600 MHz, CDC13): δ 2.36 (3H, s), 3.86 (3H, s), 6.90 (1H, dd, J = 8.44, 0.46 Hz), 7.08 (1H, dd, J = 1.72, 0.46 Hz), 7.20-7.38 (3H, 7.20 (ddd, J = 7.89, 1.28, 1.08 Hz), 7.21 (ddd, J = 8.52, 7.89, 0.44 Hz), 7.32 (dd, J = 8.44, 1.72 Hz), 7.94-7.98 (2H, 8.00 (ddd, J = 1.55, 1.28, 0.44 Hz), 8.05 (ddd, J = 8.52, 1.55, 1.08 Hz), 8.52 (1H, s). 13 C NMR (151 MHz, CDC13): 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 example and example 1 is that the solution added dropwise in step two 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 is identical to the procedure and process parameters, and the product yield is 89%.

[0050] Product test data are as follows: m.p.: 102.9-103.1 °C; 1 H NMR (600 MHz, CDC13): 3.84 (3H, s), 3.87 (3H, s), 6.76 (IH, dd, J = 8.44, 0.46 Hz), 7.12 (IH, ddd, J = 8.33, 1.24, 0.47 Hz), 7.27 (IH, ddd, J = 8.08, 7.35, 1.24 Hz), 7.26 (IH, dd, J = 1.72, 0.46 Hz), 7.52 (IH, dd, J = 8.44, 1.72 Hz), 7.69 (IH, ddd, J = 8.33, 7.35, 1.45 Hz), 7.91 (IH, ddd, J = 8.08, 1.45, 0.47 Hz), 8.92 (IH, s). 13 C NMR (151 MHz, CDC13): 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 example and example 1 is that the solution added dropwise in step two 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 is identical to the procedure and process parameters, and the product yield is 89%.

[0053] Product test data are as follows: m.p.: 102.9-103.1 °C; 1H NMR (600 MHz, CDC13): δ 3.84 (3H, s), 6.66 (IH, dd, J = 3.37, 1.75 Hz), 6.76 (IH, dd, J = 8.44, 0.46 Hz), 7.26 (IH, dd, J = 1.72, 0.46 Hz), 7.33 (IH, dd, J = 3.37, 0.88 Hz), 7.52 (IH, dd, J = 8.44, 1.72 Hz), 7.91 (IH, dd, J = 1.75, 0.88 Hz), 8.93 (IH, s). 13 C NMR (151 MHz, CDC13): 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] Into a 250 mL round bottom flask, 10.0 mmol of 5-methylsalicylaldehyde, 15.0 mmol of hydroxylamine hydrochloride, 20.0 mmol of sodium acetate (to provide a basic environment), 5 mL of water and 15 mL of absolute ethanol were added. The reaction was heated to 80 °C and stirred 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 of ice water. White solid was precipitated and dried to obtain the crude product. The crude product was purified by recrystallization using petroleum ether and ethyl acetate to obtain the white solid oxime intermediate bl;

[0057] The structural formula of the oxime intermediate bl is:

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

[0059] Into a 250 mL round bottom flask was placed 5.0 mmol of oxime intermediate b1, 5 mmol of pyridine (as a base catalyst) and 10 mL of dichloromethane, the reaction system was turbid, after stirring under ice bath conditions (0-5 °C), 6.0 mmol of benzoyl chloride in 10 mL of dichloromethane was added dropwise, the reaction progress was monitored by thin layer chromatography (TLC), until the reaction was completed (the reaction solution was clear and transparent at the time of reaction completion), the reaction time was 3-4 h, 50 mL of distilled water was added and extracted with dichloromethane, the organic phase was combined and dried with anhydrous Na2SO4, then filtered and evaporated under reduced pressure, then treated with silica gel column to obtain pure (E)-2-hydroxy-5-methylbenzaldehyde O-benzoyl oxime, the product yield was 84%.

[0060] The product detection data were as follows: m.p: 127.0-127.8 °C; 1 H NMR (600 MHz, CDC13): δ 2.31 (3H, s), 6.82 (1H, dd, J = 8.38, 0.46 Hz), 7.14 (1H, dd, J = 8.38, 1.83 Hz), 7.40-7.66 (4H, 7.45 (dd, J = 1.83, 0.46 Hz), 7.49 (dddd, J = 8.48, 7.50, 1.32, 0.45 Hz), 7.60 (tt, J = 7.50, 1.43 Hz), 8.06 (2H, dddd, J = 8.48, 1.85, 1.43, 0.45 Hz), 9.71 (1H, s). 13 C NMR (151 MHz, CDC13): 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 example and Example 7 was that the solution added dropwise in step two was 6.0 mmol of 3-methylbenzoyl chloride in 10 mL of dichloromethane, and the final product was pure (E)-2-hydroxy-5-methylbenzaldehyde O-(3-methylbenzoyl) oxime, which had the same steps and process parameters as the step, and the product yield was 82%.

[0063] The product detection data were as follows: m.p: 142.2-142.9 °C; 1H NMR (600 MHz, CDC13): δ 2.32 (3H, s), 2.44 (3H, s), 6.82 (IH, dd, J = 8.38, 0.46 Hz), 7.14 (IH, dd, J = 8.38, 1.83 Hz), 7.39 (IH, ddd, J = 7.89, 1.28, 1.08 Hz), 7.45 (IH, dd, J = 1.83, 0.46 Hz), 7.51 (IH, ddd, J = 8.52, 7.89, 0.44 Hz), 7.95 (IH, ddd, J = 1.55, 1.28, 0.44 Hz), 8.60 (IH, ddd, J = 8.52, 1.55, 1.08 Hz), 10.12 (IH, s). 13 C NMR (151 MHz, CDC13): 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 (+ve source).

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

[0065] This example differs from Example 7 in that the solution added dropwise in Step two 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. The product yield is 84% with the same procedure and process parameters as in Step two.

[0066] Product test data are as follows: m.p.: 162.8-164.3 °C; 1 H NMR (600 MHz, CDC13): δ 2.32 (3H, s), 2.44 (3H, s), 6.82 (IH, dd, J = 8.38, 0.46 Hz), 7.14 (IH, dd, J = 8.38, 1.83 Hz), 7.39 (IH, ddd, J = 7.89, 1.28, 1.08 Hz), 7.45 (IH, dd, J = 1.83, 0.46 Hz), 7.51 (IH, ddd, J = 8.52, 7.89, 0.44 Hz), 7.95 (IH, ddd, J = 1.55, 1.28, 0.44 Hz), 8.60 (IH, ddd, J = 8.52, 1.55, 1.08 Hz), 10.12 (IH, s). 13C NMR (151 MHz, CDC13): 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 (+ve source).

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

[0068] This example differs from Example 7 in that the solution added dropwise in Step two was 10 mL of dichloromethane containing 6.0 mmol of furan carboxylic acid chloride and the final product was pure (E)-2-hydroxy-5-methylbenzaldehyde O-furan-2-carbonyl oxime. The procedure was the same as in Step two and the product yield was 87%.

[0069] Product testing data were as follows: m.p.: 131.6-133.2 °C; 1 H NMR (600 MHz, CDC13): δ 2.36 (3H, s), 6.66 (1H, dd, J = 3.37, 1.75 Hz), 6.82 (1H, dd, J = 8.38, 0.46 Hz), 7.14 (1H, dd, J = 8.38, 1.83 Hz), 7.33 (1H, dd, J = 3.37, 0.88 Hz), 7.45 (1H, dd, J = 1.83, 0.46 Hz), 7.81 (1H, dd, J = 1.75, 0.88 Hz), 10.89 (1H, s). 13 C NMR (151 MHz, CDC13): 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 (+ve source).

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

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

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

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

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

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

[0076] The product detection data are as follows: m.p: 152.3-152.8 °C; 1 H NMR (600 MHz, CDCl3): δ 3.86 (6H, s), 7.01 (2H, d, J = 1.95 Hz), 7.43-7.66 (3H, 7.49 (dddd, J = 8.48, 7.50, 1.32, 0.45 Hz), 7.60 (tt, J = 7.50, 1.43 Hz), 7.95 (2H, dddd, J = 8.48, 1.85, 1.43, 0.45 Hz), 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 example and Example 10 is that the solution added dropwise in Step 2 is 10 mL of dichloromethane containing 6.0 mmol of 3-methylbenzoyl chloride, and the final product is pure (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-(3-methylbenzoyl) oxime, which is identical to the procedure and process parameters, and the product yield is 76%.

[0079] The product was detected as follows: m.p.: 112.8-113.9 °C; 1 H NMR (600 MHz, CDC13): δ 2.44 (3H, s), 3.87 (6H, s), 6.51 (2H, d, J = 1.95 Hz), 7.33-7.57 (2H, 7.39 (ddd, J = 7.89, 1.28, 1.08 Hz), 7.51 (ddd, J = 8.52, 7.89, 0.44 Hz), 7.94-8.08 (2H, 8.00 (ddd, J = 1.55, 1.28, 0.44 Hz), 8.02 (ddd, J = 8.52, 1.55, 1.08 Hz), 8.55 (1H, s). 13 C NMR (151 MHz, CDC13): 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- methoxyphenylcarbonyl) oxime

[0081] The difference between this example and Example 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-methoxyphenylcarbonyl) oxime, which is identical to the procedure and process parameters, and the product yield is 82%.

[0082] The product was detected as follows: m.p.: 107.2-109.0 °C; 1H NMR (600 MHz, CDC13): δ 3.91 (3H, s), 3.93 (3H, s), 6.80 (2H, d, J = 1.95 Hz), 6.92 (1H, ddd, J = 8.33, 1.24, 0.47 Hz), 7.07 (1H, ddd, J = 8.08, 7.35, 1.24 Hz), 7.29 (1H, ddd, J = 8.33, 7.35, 1.45 Hz), 7.51 (1H, ddd, J = 8.08, 1.45, 0.47 Hz), 8.18 (1H, s). 13 C NMR (151 MHz, CDC13): 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] This example differs from Example 10 in that the solution added dropwise in Step 2 is 10 mL of dichloromethane containing 6.0 mmol of furan carboxylic acid chloride, and the final product is pure (E)-4-hydroxy-3,5-dimethoxybenzaldehyde O-furan-2-carbonyl oxime, which is identical to the procedure and process parameters, and the product yield is 83%.

[0085] The product test data are as follows: m.p.: 123.4-124.1 °C; 1 H NMR (600 MHz, CDC13): δ 3.91 (3H, s), 3.93 (3H, s), 6.80 (2H, d, J = 1.95 Hz), 6.92 (1H, ddd, J = 8.33, 1.24, 0.47 Hz), 7.07 (1H, ddd, J = 8.08, 7.35, 1.24 Hz), 7.29 (1H, ddd, J = 8.33, 7.35, 1.45 Hz), 7.51 (1H, ddd, J = 8.08, 1.45, 0.47 Hz), 8.18 (1H, s). 13 C NMR (151 MHz, CDC13): 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).

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

[0087]

[0088] wherein R1 is as shown in one of a, b, c; R2 is one of H, methyl, methoxy.

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

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

[0091]

[0092]

[0093] Application Example 1 Herbicidal Activity Test

[0094] The herbicidal activity of the oxime ester-containing compounds prepared in Examples 1-12 was determined. The test targets were monocotyledonous weeds: Setaria viridis, Echinochloa crus-galli and Digitaria sanguinalis, and dicotyledonous weeds: Portulaca oleracea, Abutilon theophrasti and Amaranthus retroflexus. The commercial PPO inhibitor, oxyfluorfen, was used as a positive control. When the weeds were at the two-leaf stage, the target compounds were prepared at different concentrations and sprayed on the leaves of the weeds. The growth state of the weeds was visually evaluated. Most of the weed plants showed symptoms such as burning, curling and yellowing after 1 day of spraying, and whitening and death after 2-3 days. The greenhouse herbicidal activity of all the compounds was expressed as a percentage of inhibition, and the results are shown in Table 2.

[0095] The preparation process was as follows: 10 mg of the compound prepared in the examples was dissolved in N,N-dimethylformamide (DMF), Tween-80 was added as an emulsifier, and then distilled water was added to dilute to 10 mL, to prepare a stock solution with a concentration of 1 g / L. When spraying, an appropriate amount of the stock solution was removed with a pipette and diluted with distilled water, so that the application rate was 300, 150, 75, 37.5 g ai / ha, respectively.

[0096]

[0097]

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

[0099] As can be seen from the data in Table 2, most of the compounds synthesized in Examples 1-12 have better inhibitory activity on dicotyledonous weeds than on monocotyledonous weeds; among the dicotyledonous weeds, the target compounds have slightly higher inhibitory activity on Portulaca than on Abutilon and Amaranthus. Most of the target compounds exhibit more than 80% inhibitory activity on weeds at a dose of 300 g ai / ha. The compounds containing hydroxamate structures prepared in Examples 4, 8 and 12 exhibit excellent herbicidal activity, with an inhibition rate close to 100% on six weeds at a dose of 300 g ai / ha, and the compound prepared in Example 12 has more than 80% inhibitory activity on most weeds even at a low dose of 37.5 g ai / ha, thus having excellent greenhouse herbicidal activity, which is comparable to or slightly better than that of the commercial PPO inhibitor, oxyfluorfen.

[0100] Safety experiment of application example 2

[0101] Safety determination experiment was performed on the compound containing hydroxamate structure prepared in Example 12. Test targets: rice, peanut, corn, wheat and cotton.

[0102] The test method was a greenhouse small cup method: a certain amount of soil passing through a 5 mm sieve was taken, and the selected crop seeds were soaked in warm water for 12 h and incubated in a 25°C incubator for 24 h. Eight uniform and well germinated crop seeds were evenly placed on the surface of the soil with the plumule facing downward, and about 10 g of dry soil was covered thereon. The culture was incubated under the conditions of a temperature of 26.5°C, a humidity of 75%, and a light and dark cycle of 12 h each, and when the crops grew to the three-leaf stage, the compound prepared in Example 12 was sprayed on the leaves of the five crops at a dose of 75-300 g ai / ha. The leaf damage and growth of the plants were observed regularly. The crop safety of the compound was finally evaluated by visual observation within 2 weeks after spraying. Oxyfluorfen was used as a control agent, and each experiment was repeated three times.

[0103] Table 3 Safety of the compound containing hydroxamate structure prepared in Example 12 and the commercial PPO inhibitor oxyfluorfen on post-emergence crops

[0104]

[0105] As can be seen from the detection data in Table 3, the compound containing hydroxamate structure prepared in Example 12 can be used as a herbicide, and rice, corn, peanut and wheat exhibit high tolerance to the compound at a dose of 300 g ai / ha. In addition, the compound containing hydroxamate structure prepared in Example 12 has selectivity to rice, corn, peanut and wheat, while the commercial PPO inhibitor oxyfluorfen has selectivity only to 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 dose.

[0106] The above description is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A compound having an hydroxamic ester structure, characterized in that, The structural formula of the compound is shown in formula I or formula II: Wherein, the structure of R1 is shown in one of a, b, c; R2 is one of H, methyl, methoxy; The compound containing the hydroxamic ester structure is used as a pesticide to control crop weeds; The weeds are at least one of Digitaria sanguinalis, Setaria viridis, Echinochloa crus-galli, Portulaca oleracea, Amaranthus retroflexus, and Abutilon theophrasti. The crops are rice, peanut, corn, wheat, and cotton. The compound containing the hydroxamic ester structure is used as an active ingredient to prepare a weed control agent.

2. A process for the preparation of a compound containing an hydroxamic ester structure according to claim 1, characterized in that, Comprise: Step one: dissolve sodium acetate, hydroxylamine hydrochloride, and one of 3-hydroxy-4-methoxybenzaldehyde, 5-methyl salicylaldehyde, and 3,5-dimethoxy-4-hydroxybenzaldehyde in a solvent, and react; after the reaction is completed, pour the reaction solution into ice water immediately to precipitate white solids; dry and purify the white solids to obtain an oxime intermediate; Step two: dissolve the oxime intermediate and a catalyst in a solvent, add dichloromethane containing an acyl chloride substance, and react; after the reaction is completed, sequentially perform extraction, drying, filtration, reduced pressure evaporation, and silica gel column treatment to obtain a compound containing a hydroxamic ester structure; The structure of the oxime intermediate in step one is , or ; The acyl chloride substance in step two is benzoyl chloride, 3-methylbenzoyl chloride, 2-methoxybenzoyl chloride, or furanoyl chloride.

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

4. The production method according to claim 2, characterized by, In step one, the reaction temperature is 80-90°C; the time is 4-6 h; 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 two, 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, In step two, the reaction temperature is 0-5°C.

7. The compound containing the hydroxamic ester structure of claim 1 as a pesticide for controlling crop weeds; The weeds are at least one of Digitaria sanguinalis, Setaria viridis, Echinochloa crus-galli, Portulaca oleracea, Amaranthus retroflexus, and Abutilon theophrasti.

8. The compound containing the hydroxamic ester structure of claim 1 as an active ingredient for preparing a weed control agent; The weeds are at least one of Digitaria sanguinalis, Setaria viridis, Echinochloa crus-galli, Portulaca oleracea, Amaranthus retroflexus, and Abutilon theophrasti.

9. Use according to claim 8, characterized in that, The compound containing the hydroxamic ester structure in the agent is applied at a concentration of 37.5-300 g ai / ha.

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