Thione organic compounds and their use

Abstract

This application provides a thionone organic compound and its application. The thionone organic compound includes at least one compound having the structure shown in formula (I) and its tautomers: (I). This application provides a novel organic compound that, by employing a biheterocyclic -1,3,4-oxadiazole (thiadiazole, triazole)-thionone skeleton structure and through specific heterocyclic combinations, exhibits excellent agricultural fungicidal and bactericidal activity, is suitable for inhibiting the activity of various fungi and bacteria, has good broad-spectrum bactericidal activity, and can be used as a pesticide for controlling fungal and bacterial diseases.

Description

Technical Field

[0001] This invention relates to the field of pesticide compound technology, specifically to a thionolite organic compound and its application. Background Technology

[0002] Plant diseases caused by fungi or bacteria are a significant factor affecting the economic yield of crops. To ensure agricultural production and the quality of agricultural products, it is necessary to develop compounds with better control effects against fungal or bacterial diseases. Summary of the Invention

[0003] In view of this, embodiments of this application provide a thionolite organic compound and its application, aiming to provide an organic compound with better prevention and control effects against diseases caused by fungi or bacteria.

[0004] In a first aspect, this application provides a thionone-type organic compound, comprising at least one compound having the structure shown in formula (I) and its tautomers:

[0005] (I)

[0006] Where X is selected from S, O or N;

[0007] Het 1 It is selected from any one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted furanyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrroleyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted morpholinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted benzothiazolyl, and substituted or unsubstituted triazolyl.

[0008] Het 2 It is selected from any one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted furanyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrroleyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted morpholinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted benzothiazolyl, and substituted or unsubstituted triazolyl.

[0009] Each substituent is independently selected from C1 to C1 each time it appears. 12 Alkyl, C2~C 12 Unsaturated hydrocarbon groups, C1~C 12 Any one or more combinations of alkoxy, halogen, nitro, cyano, ester, and aldehyde groups.

[0010] Secondly, this application provides a bactericidal composition comprising a carrier and a thion-type organic compound as described above.

[0011] Thirdly, this application provides the use of the thion-type organic compounds as described above in the preparation of pesticides, which are used to control crop diseases caused by fungi and / or bacteria.

[0012] This application provides a novel organic compound that, by adopting a bicyclic heterocyclic -1,3,4-oxadiazole (thiadiazole, triazole)-thione skeleton structure and through specific heterocyclic combinations, gives the compound excellent agricultural fungicidal and bactericidal activity. It is suitable for inhibiting the activity of various fungi and bacteria, has good broad-spectrum bactericidal properties, and can be used as a pesticide for the prevention and control of fungal and bacterial diseases.

[0013] Furthermore, the organic compound synthesis method provided in this application is simple, the starting materials are readily available and easy to process, and can be prepared into a variety of pesticide formulations to meet the needs of different conditions and application scenarios. Detailed Implementation

[0014] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0015] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0016] In the description of the embodiments of this application, the term "at least one" means one or more, and "more than one" means two or more (including two). For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be a single or multiple.

[0017] In this application, "substituted or unsubstituted" means that the defined group may or may not be substituted by a substituent. When a substituent appears multiple times, it may be independently selected from different groups.

[0018] In this application, "alkyl" can refer to straight-chain alkyl and / or branched alkyl, and "cycloalkyl" refers to cyclic alkyl. 1-12 Alkyl groups are defined as having 1-12 carbon atoms, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12. Non-limiting examples of alkyl groups include ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 2-ethylpentyl, n-hexyl, 1-methylhexyl, n-heptyl, 1-methylheptyl, n-octyl, tert-octyl, n-nonane, n-decane, n-undecane, n-dodecane, etc. "Alkoxy" refers to a group with the structure "-O-alkyl", meaning that the alkyl group as defined above is attached to another group via an oxygen atom. Phrases containing the term, suitable examples of which include, but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and tert-butoxy (-OC(CH3)3 or -OtBu).

[0019] In this application, an unsaturated hydrocarbon group refers to a group containing at least one of a carbon-carbon double bond structure and a carbon-carbon triple bond structure.

[0020] In this application, the single bonds connecting the substituents extend through the corresponding ring, indicating that the substituent can be attached to any position on the ring. For example, in formula (I), Het 1 Can be used with Het 2 Any substituted site in the ring is connected.

[0021] The terms “combinations thereof,” “any combination thereof,” and “any combination thereof” as used in this application include all suitable combinations of any two or more of the listed items. For example, “substituents selected from a combination of multiple groups” represents a combination group formed by substituting one of the groups as the main body and other groups as substituents to replace the hydrogen in the main group. For example, the substituents can be a combination of fluorine and methyl, i.e., fluorinated methyl (-CH2F, -CHF2, or -CF3).

[0022] This application describes the design and synthesis of a thionolite organic compound, which includes at least one compound having the structure shown in formula (I) and its tautomers:

[0023] (I)

[0024] Where X is selected from S, O or N;

[0025] Het 1 Selected from any one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted furanyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrroleyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted thiopheneyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted morpholinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted benzothiazolyl, and substituted or unsubstituted triazolyl; Het 2 It is selected from any one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted furanyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrroleyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted morpholinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted benzothiazolyl, and substituted or unsubstituted triazolyl.

[0026] Each substituent is independently selected from C1 to C1 each time it appears. 12 Alkyl, C2~C 12 Unsaturated hydrocarbon groups, C1~C 12 Any combination of one or more of the following: alkoxy, halogen (e.g., -F, -Cl, -Br, or -I), nitro (-NO2), cyano (-CN), ester (-COOR, where R is an alkyl group), and aldehyde (-CHO). It can be understood that when Het 1 Het 2 When at least two of the selected groups are substituents, the substituents may be the same or different.

[0027] It is understood that the thionoid organic compounds proposed in this application not only include compounds having the structure shown in formula (I), but may also include their tautomers that can be represented by formula (II), where Het 1 、X,Het 2 Both the substituents and the substituents have the meaning given in equation (I) above.

[0028] (II)

[0029] The technical solution proposed in this application provides a novel organic compound with thion as the core. By splicing it with a bicyclic heterocycle, a bicyclic-1,3,4-oxadiazole (thiadiazole, triazole)-thion skeleton structure is formed. The bicyclic heterocycle is optimized by selecting specific heterocycles for combination. Through skeletal transitions and isochoric arrangements of different active heterocycles, the compound exhibits excellent agricultural fungicidal and bactericidal activity. It is suitable for inhibiting the activity of various fungi and bacteria, possesses good broad-spectrum bactericidal properties, and can be used as a pesticide for controlling fungal and bacterial diseases. Furthermore, the organic compound provided in this application has a simple synthesis method, readily available starting materials, and is easy to process, allowing for the preparation of various pesticide formulations to meet the needs of different conditions and application scenarios.

[0030] In a preferred embodiment, each substituent is independently selected from C1 to C1. 12 Alkyl groups make starting materials easier to obtain and target compounds easier to synthesize.

[0031] In some embodiments, Het 1 Selected from any one of substituted or unsubstituted pyridyl, substituted or unsubstituted furanyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrroleyl, and substituted or unsubstituted thiophenyl; further, as a preferred embodiment, Het 1 Selected from any one of pyrrole, pyridyl, pyrimidinyl, furanyl, and thiopheneyl. Through the analysis of Het... 1 Further optimization can help reduce the difficulty of synthesizing the target compound and further enhance its bactericidal activity.

[0032] In some embodiments, Het 2 Selected from any one of substituted or unsubstituted furanyl, substituted or unsubstituted pyrroleyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted thiophenyl, and substituted or unsubstituted morpholinyl; further, as a preferred embodiment, Het 2 Selected from any one of furanyl, pyrroleyl, substituted or unsubstituted pyrazolyl, thiophenyl, and morpholinyl. Through the analysis of Het... 2 Further optimization can help reduce the difficulty of synthesizing the target compound and further enhance its bactericidal activity.

[0033] Furthermore, as a preferred embodiment, when X is 0 and Het 1 and Het 2 When at least one of the compounds is selected from the thiophene ring, it helps to balance the inhibitory effects of thiophene organic compounds on both bacteria and fungi.

[0034] In some specific embodiments, the thionolite organic compounds are selected from one or more compounds having structural formulas 1a, 1b, 1c, 21a, 21b, 21c, 41a, 161a, 241a, and 301a, and their tautomers (1A, 1B, 1C, 21A, 21B, 21C, 41A, 161A, 241A, and 301A). Specifically, the structural formulas of the above compounds and their tautomers are as follows:

[0035] .

[0036] Furthermore, this application also proposes a method for synthesizing thion-type organic compounds, which can prepare the aforementioned thion-type organic compounds. Specifically, the synthesis method includes the following steps:

[0037] Based on the structural formula of the target compound, select compounds with the same Het... 1 Compounds with the same structure and conforming to the structural formula of compound a, as well as compounds with the same Het 2 A compound with the structure conforming to the structural formula of compound b is used as the starting compound, and the following reaction is carried out:

[0038] S1, Compound a and Compound b are mixed and subjected to the Suzuki reaction to obtain intermediate A;

[0039] S2, intermediate A and hydrazine hydrate are mixed and subjected to hydrazolysis to obtain intermediate B;

[0040] S3, the intermediate B is subjected to a cyclization reaction to obtain the target compound;

[0041] ;

[0042] .

[0043] In the Suzuki reaction, the reaction temperature is determined by heating the reaction system to reflux, and then reacting at reflux temperature for 18-24 h. A palladium complex catalyst can be added during the reaction, and the molar ratio of compound a, compound b, and the palladium complex catalyst is (15-16):(10-11):(0.25-0.3). The catalyst can be Pd[PPh3]4.

[0044] In the hydrazine hydrolysis reaction, the reaction temperature is determined by heating the reaction system to reflux, and then reacting at reflux temperature for 4-5 hours. The molar ratio of compound A to hydrazine hydrate is 1:2.9-3.3.

[0045] In cyclization reactions, different cyclization routes can be adopted depending on the specific choice of X in the chemical formula of the target compound. For details, refer to commonly used cyclization methods in the field of organic synthesis. For example:

[0046]

[0047] When X is O, intermediate B, potassium hydroxide, and methanol can be mixed, and then carbon disulfide can be added to carry out a cyclization reaction to obtain the target compound C. Specifically, the cyclization reaction is carried out at a temperature where the reaction system is heated to reflux, and then reacted at reflux temperature for 8-10 hours. The pH is then adjusted to 5-6 with dilute hydrochloric acid to obtain the target compound C. The molar ratio of intermediate B, potassium hydroxide, and carbon disulfide is 1:(2-2.2):(2.48-2.6).

[0048] When X is S, intermediate B, potassium hydroxide, and methanol can be mixed, and then carbon disulfide can be added to carry out a cyclization reaction. After obtaining a solid product, the solid product is added to concentrated sulfuric acid under ice-salt bath conditions to obtain the target compound D. Specifically, the cyclization reaction temperature is determined by heating the reaction system to reflux, and then reacting at reflux temperature for 8-10 hours; the molar ratio of intermediate B, potassium hydroxide, and carbon disulfide is 1:(2-2.2):(2.48-2.6).

[0049] When X is N, intermediate B, potassium thiocyanate, and hydrochloric acid can be mixed, heated to reflux, and stirred for 8-12 h to obtain a solid product. Then, the solid product is mixed with an aqueous solution of KOH and reacted at 105-110℃ for 4-8 h to obtain the target compound E. The molar ratio of intermediate B, potassium thiocyanate, and hydrochloric acid is 1:(2-2.2):(1-1.2).

[0050] It is understandable that, in actual preparation, an appropriate synthesis method can be selected based on the specific structure of the target thion-type organic compound and the compounds with the same structure in the above synthetic route.

[0051] It is understood that the above synthetic method is applicable not only to compounds having the structure shown in formula (I), but also to tautomers of compounds having the structure shown in formula (II). The product obtained by the above synthetic method substantially includes the desired compound (I) in equilibrium with its tautomer (II).

[0052] Furthermore, this application also proposes a bactericidal composition comprising a carrier and a thionyl organic compound as described above. The bactericidal composition exhibits good bactericidal effects and can prevent and control crop diseases caused by fungi or bacteria, particularly effective against diseases caused by pathogens of wheat sheath blight, rapeseed sclerotinia rot, rice sheath blight, wheat take-all, corn stem rot, rice blast, rice bacterial blight, and rice bacterial streak. In practical preparation, the carrier and the thionyl compound can be mixed to obtain the bactericidal composition.

[0053] The carrier in the bactericidal composition can be a substance that, when formulated with the active ingredient (e.g., a thionyl ketone organic compound), is easily applied to the site to be treated, such as a plant, seed, or soil; or is convenient for storage, transportation, or handling. The carrier can be solid or liquid, and generally any carrier used in the formulation of the bactericidal composition can be used.

[0054] Specifically, the carrier may include, but is not limited to, one or more of the following: diatomaceous earth, talc, magnesia, kaolin, calcium carbonate, calcium sulfate, silicon dioxide, calcium silicate, aluminum silicate, montmorillonite, mica, alcohols, ketones, resins, polyvinyl chloride and styrene polymers or copolymers, water, aromatics, petroleum fractions, biodiesel, modified vegetable oils, dimethyl sulfoxide, and dichloromethane; the alcohols include ethanol or isopropanol; the ketones include acetone, methyl ethyl ketone, methyl isopropyl ketone, or cyclohexanone; the aromatics include benzene, toluene, xylene, or solvent oils; the resins include benzofuran resins; and the petroleum fractions include kerosene or mineral oil.

[0055] The bactericidal composition is available in various dosage forms, including but not limited to emulsifiable concentrates, wettable powders, powders, granules, effervescent tablets, suspensions, microemulsions, or water-dispersible granules. In addition to carriers and thiophene compounds, the bactericidal composition may also include other active ingredients, adjuvants, and additives, such as other active compounds with preventative and therapeutic effects, surfactants, etc.

[0056] Furthermore, this application also proposes an application. Specifically, the thion-type organic compounds proposed in this application possess excellent bactericidal activity and can be prepared into formulations such as emulsifiable concentrates, which are easily penetrated and exert bactericidal effects, providing good control over crop diseases caused by fungi or bacteria. Therefore, they can be used to prepare pesticides, for example, by mixing a carrier with thion-type compounds to create pesticides that exert bactericidal and disease-controlling effects.

[0057] The types of fungi may include, but are not limited to, at least one of the following: Oomycetes, Basidiomycetes, Zygomycetes, Chytridiomycetes, Ascomycetes, and Deuteromycetes; the fungi may include, but are not limited to, the pathogens of wheat sheath blight, rapeseed sclerotinia rot, rice sheath blight, wheat take-all, maize stem rot, and rice blast.

[0058] The bacteria can be at least one of Gram-negative and Gram-positive bacteria. Specifically, the Gram-negative bacteria include at least one of the following genera: Erwinia, Pectinobacterium, Diggia, Pantotheca, Pseudomonas, Rhesus, Burkholderia, Acidophilus, Xanthomonas, Agrobacterium, Microcephala, Phloemobacterium, Enterobacter, and Lignophilic Bacteria. The Gram-positive bacteria include at least one of the following genera: Corynebacterium, Streptomyces, Bulbacterium, Arthrobacter, Rhodococcus, Bacillus, and Lassella. For example, this method can control rice bacterial blight and rice bacterial leaf streak caused by Xanthomonas.

[0059] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0060] In the following examples and comparative examples, expressions like "(3×50 mL)" represent the number of times × the amount used each time. For example, extraction with CH2Cl2 (3×50 mL) means that dichloromethane was used for three extractions, with each extraction using 50 mL.

[0061] Example 1

[0062] This embodiment presents the synthesis of 5-(4-methyl-2-(thiophen-2-yl)thiazolyl-5-yl)-1,3,4-oxadiazole-2(3H)-thione (1a).

[0063] Its synthesis method is as follows: 1) Synthesis of ethyl 4-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-carboxylate:

[0064]

[0065] Pd[PPh3]4 (0.25 mmol), 2-thiopheneboronic acid (15.00 mmol), ethyl 3-bromo-4-methyl-1H-pyrazole-5-carboxylate (10.00 mmol), and an aqueous solution of Na2CO3 (1 mol / L, 50 mL) were added to a round-bottom flask containing a mixture of 1,4-dioxane and water (10:1, v / v) to obtain a reaction mixture. The reaction mixture was heated to reflux and stirred at reflux temperature for 24 hours. After the reaction was monitored by TLC until complete, 1,4-dioxane was removed by rotary evaporation under reduced pressure to obtain an aqueous phase, which was then extracted with CH2Cl2 (3 × 50 mL), and the organic phase was collected. The obtained organic phase was dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain a concentrated residue. The concentrated residue was purified by silica gel column chromatography (EA / PE = 1:5, v / v) to obtain ethyl 4-methyl-5-(thien-2-yl)-1H-pyrazole-3-carboxylate.

[0066] 2) Synthesis of 4-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-carboxylhydrazide:

[0067]

[0068] Hydrazine hydrate (10.90 mmol) was slowly added to a methanol (30 mL) solution containing ethyl 4-methyl-5-(thien-2-yl)-1H-pyrazole-3-carboxylate (3.63 mmol), and the mixture was stirred at reflux for 4 h. After the reaction was complete (monitored by TLC), the crude product precipitate was filtered and purified by washing several times with water to obtain 4-methyl-5-(thien-2-yl)-1H-pyrazole-3-carboxyhydrazide.

[0069] 3) 5-(4-methyl-5-(thiophen-2-yl)-1H-pyrazol-3-yl)-1,3,4-oxadiazole-2(3 H Synthesis of thiophene:

[0070]

[0071] In a 250 mL flask containing 50 mL of methanol, 3.09 mmol of 4-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-carboxylhydrazine and 6.18 mmol of potassium hydroxide were added and dissolved, followed by the slow addition of carbon disulfide (7.72 mmol). The mixture was stirred at room temperature for 30 min, then heated and refluxed for 8 h. After the reaction was complete (monitored by TLC), the mixture was diluted with ice water and the pH was adjusted to 5–6 with dilute hydrochloric acid. The solution was filtered and recrystallized from methanol to obtain the purified target compound.

[0072] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, 224.8–226.7 °C. 1 H NMR (400 MHz, CDCl3) d 7.38 (dd, J = 4.9, 1.8 Hz, 1H), 7.26 – 7.24 (m,1H), 7.17 (dd, J = 5.9, 4.9 Hz, 1H), 3.58 (s, 3H). 13 C NMR (101 MHz, CDCl3) d :180.60, 152.23, 136.50, 134.73, 131.13, 128.27, 127.42, 126.42, 117.04, 10.48.

[0073] Example 2

[0074] This embodiment proposes 5-(4-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-yl)-1,3,4-thiadiazole-2(3 H )-Thione (1b). Its synthesis method is basically the same as in Example 1, except that step 3) is changed to:

[0075]

[0076] In a 250 mL flask, 7.2 mmol of 3-(thien-2-yl)-2-pyrazoline-1-carbonylhydrazine, 15.4 mmol of potassium hydroxide, and 25.6 mmol of carbon disulfide were added sequentially, and the mixture was stirred under reflux for 6 h. After the reaction was complete (monitored by thin-layer chromatography), the solution was cooled to room temperature and filtered to obtain a white solid. The resulting turquoise solid was then subjected to an ice-salt bath with 15 mL of 98% sulfuric acid. After the reaction was complete, the target compound was obtained by filtration, washing, and recrystallization.

[0077] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, >220 °C. 1 H NMR (400 MHz, CDCl3) d 7.38 (dd, J = 4.9, 1.8 Hz, 1H), 7.27 (dd, J = 6.0, 1.7 Hz, 1H), 7.17 (dd, J = 6.0, 5.0 Hz, 1H), 3.57 (s, 3H).13 C NMR (101 MHz, CDCl3) d :189.77, 149.25, 137.15, 135.02, 128.17, 127.42, 127.37, 126.33, 113.66, 10.25.

[0078] Example 3

[0079] This embodiment proposes 5-(4-methyl-5-(thien-2-yl)-1H-pyrazole-3-yl)-2,4-dihydro-3 H -1,2,4-triazol-3-thione (1c). Its synthesis method is basically the same as in Example 1, except that step 3) is changed to:

[0080]

[0081] In a 250 mL flask, 10 mmol of 3-(thiophene-2-yl)-2-pyrazoline-1-carbonylhydrazine, 20 mmol of KSCN, and 10 mmol of hydrochloric acid were added sequentially, and the mixture was stirred under reflux for 12 h. After the reaction was complete (monitored by thin-layer chromatography), the solution was cooled to room temperature and filtered to obtain a white solid. The white solid was then refluxed with KOH solution at 105 °C for 4 h. After the reaction was complete, the pH was adjusted to 3–4 with hydrochloric acid. A large amount of solid precipitated out, which was filtered to obtain the target compound.

[0082] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, >220 °C. 1 H NMR (400 MHz, CDCl3) d 7.38 (dd, J = 4.9, 1.8 Hz, 1H), 7.26 (dd, J = 6.0, 1.7 Hz, 1H), 7.17 (dd, J = 6.0, 5.0 Hz, 1H), 3.53 (s, 3H). 13 C NMR (101 MHz, CDCl3) d :171.53, 143.53, 136.56, 134.24, 129.00, 128.28, 127.42, 126.36, 114.32, 10.27.

[0083] Example 4

[0084] This embodiment proposes 5-(4-methyl-2-(thien-2-yl)thiazolyl-5-yl)-1,3,4-oxadiazole-2(3 H )-Thione (21a). Its synthesis method is as follows:

[0085] 1) Synthesis of ethyl-[2,2'-bithiophene]-5-carboxylate:

[0086]

[0087] Pd[PPh3]4 (0.25 mmol), 2-thiopheneboronic acid (15.00 mmol), ethyl 5-bromothiophene-2-carboxylate (10.00 mmol), and an aqueous solution of Na2CO3 (1 mol / L, 50 mL) were added to a round-bottom flask containing a mixture of 1,4-dioxane and water (10:1, v / v) to obtain a reaction mixture. The reaction mixture was heated to reflux and stirred at reflux temperature for 24 hours. After the reaction was monitored by TLC until complete, 1,4-dioxane was removed by rotary evaporation under reduced pressure to obtain an aqueous phase, which was then extracted with CH2Cl2 (3 × 50 mL), and the organic phase was collected. The obtained organic phase was dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain a concentrated residue. The concentrated residue was purified by silica gel column chromatography (EA / PE = 1:5, v / v) to give ethyl-[2,2'-bithiophene]-5-carboxylate.

[0088] 2) Synthesis of [2,2-Bithiophene]-5-carboxyhydrazide:

[0089]

[0090] Hydrazine hydrate (10.90 mmol) was slowly added to a solution containing ethyl-[2,2'-bithiophene]-5-carboxylic acid ester (3.63 mmol) and methanol (30 mL), and stirred at reflux for 4 h. After the reaction was complete (monitored by TLC), the crude product precipitate was filtered and purified by washing several times with water to obtain [2,2-bithiophene]-5-carboxyhydrazide.

[0091] 3) 5-[5-(2-thienyl)-1,3-thiazolyl-2-yl]-1,3,4-oxadiazole-2(3 H Synthesis of thiophene:

[0092]

[0093] In a 250 mL flask containing 50 mL of methanol, [2,2-bithiophene]-5-carboxyhydrazide (3.09 mmol) and potassium hydroxide (6.18 mmol) were added and dissolved, followed by the slow addition of carbon disulfide (7.72 mmol). The mixture was stirred at room temperature for 30 min, then heated and refluxed for 8 h. After the reaction was complete (monitored by TLC), the mixture was diluted with ice water and the pH was adjusted to 5–6 with dilute hydrochloric acid. The solution was filtered and recrystallized from methanol to obtain the purified target compound.

[0094] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, 256.4–258.6 °C. 1 H NMR (400 MHz, CDCl3) d 7.47 (d, J = 5.5 Hz, 1H), 7.26 (d, J = 5.7 Hz, 1H),7.24 – 7.19 (m, 2H), 7.01 (dd, J = 5.9, 4.9 Hz, 1H). 13 C NMR (101 MHz, CDCl3) d :180.88, 152.40, 137.95, 135.02, 128.61, 127.06, 125.12, 124.98, 124.58,124.53.

[0095] Example 5

[0096] This embodiment proposes 5-(4-methyl-2-(thien-2-yl)thiazolyl-5-yl)-1,3,4-thiadiazole-2(3 H )-Thione (21b). Its synthesis method is basically the same as in Example 4, except that step 3) is changed to:

[0097]

[0098] In a 250 mL flask, [2,2-bithiophene]-5-carboxyhydrazide (7.2 mmol), potassium hydroxide (15.4 mmol), and carbon disulfide (25.6 mmol) were added sequentially, and the mixture was stirred under reflux for 6 h. After the reaction was complete (monitored by thin-layer chromatography), the solution was cooled to room temperature and filtered to obtain a white solid. The white solid was then subjected to an ice-salt bath and 98% sulfuric acid (15 mL) was added. After the reaction was complete, the target compound was obtained by filtration, washing, and recrystallization.

[0099] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, >220 °C. 1 H NMR (400 MHz, CDCl3) d 7.38 (d, J = 5.1 Hz, 1H), 7.33 (d, J = 5.1 Hz, 1H), 7.24 –7.20 (m, 2H), 7.01 (dd, J = 5.9, 4.9 Hz, 1H). 13 C NMR (101 MHz, CDCl3) d : 188.61,152.80, 138.16, 135.18, 133.16, 127.07, 125.79, 125.43, 124.67, 124.58.

[0100] Example 6

[0101] This embodiment proposes 6-([2,2'-bithiophene]-5-yl)-2,4-dihydro-3 H -1,2,4-triazol-3-thione (21c). Its synthesis method is basically the same as in Example 4, except that step 3) is changed to:

[0102]

[0103] In a 250 mL flask, [2,2-bithiophene]-5-carboxyhydrazide (10 mmol), KSCN (20 mmol), and hydrochloric acid (10 mmol) were added sequentially, and the mixture was stirred under reflux for 12 h. After the reaction was complete (monitored by thin-layer chromatography), the solution was cooled to room temperature and filtered to obtain a white solid. The obtained white solid was refluxed with KOH solution at 105 °C for 4 h. After the reaction was complete, the pH was adjusted to 3-4 with hydrochloric acid. A large amount of solid precipitated out, which was filtered to obtain the target compound.

[0104] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, >220 °C. 1 H NMR (400 MHz, CDCl3) d 7.59 (d, J = 5.9 Hz, 1H), 7.26 (d, J = 5.9 Hz, 1H), 7.25 –7.19 (m, 2H), 7.01 (dd, J = 5.9, 4.9 Hz, 1H). 13C NMR (101 MHz, CDCl3) d : 171.78,145.76, 137.79, 134.91, 127.53, 127.07, 125.75, 124.67, 124.58, 124.53.

[0105] Example 7

[0106] This embodiment proposes 5-(4-methyl-2-(thien-2-yl)thiazolyl-5-yl)-1,3,4-oxadiazole-2(3 H )-Thione (41a). Its synthesis method is as follows:

[0107] 1) Synthesis of ethyl-1-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-carboxylic acid ester:

[0108]

[0109] Pd[PPh3]4 (0.25 mmol), 2-thiopheneboronic acid (15.00 mmol), and 5-bromo-1-methyl-1 H Ethyl pyrazole-3-carboxylate (10.00 mmol) and an aqueous solution of Na₂CO₃ (1 mol / L, 50 mL) were added to a round-bottom flask containing a mixture of 1,4-dioxane and water (10:1, v / v) to obtain a reaction mixture. The reaction mixture was heated to reflux and stirred at reflux temperature for 24 hours. After the reaction was monitored by TLC until complete, 1,4-dioxane was removed by rotary evaporation under reduced pressure to obtain an aqueous phase, which was then extracted with CH₂Cl₂ (3 × 50 mL), and the organic phase was collected. The obtained organic phase was dried over anhydrous Na₂SO₄, filtered, and concentrated under reduced pressure to obtain a concentrated residue. The concentrated residue was purified by silica gel column chromatography (EA / PE = 1:5, v / v) to give ethyl-1-methyl-5-(thiophen-2-yl)-1 H -Pyrazole-3-carboxylic acid ester.

[0110] 2) 1-Methyl-5-(thien-2-yl)-1 H Synthesis of pyrazole-3-formylhydrazide:

[0111]

[0112] Hydrazine hydrate (10.90 mmol) was slowly added to a methanol (30 mL) solution containing ethyl-1-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-carboxylic acid ester (3.63 mmol), and the mixture was stirred at reflux for 4 h. After the reaction was complete (monitored by TLC), the crude product precipitate was filtered and purified by washing several times with water to obtain 1-methyl-5-(thiophen-2-yl)-1H-pyrazole-3-carboxylic acid ester. H -Pyrazole-3-formylhydrazide.

[0113] 3) 5-[1-methyl-5-(thien-2-yl)-1 H -pyrazole-3-yl]-1,3,4-oxadiazole-2(3 H Synthesis of thiophene:

[0114]

[0115] In a 250 mL flask containing 50 mL of methanol, add 1-methyl-5-(thiophen-2-yl)-1 H 3-Pyrazole-3-carboxylhydrazide (3.09 mmol) and potassium hydroxide (6.18 mmol) were dissolved, and then carbon disulfide (7.72 mmol) was slowly added. After stirring at room temperature for 30 min, the mixture was heated and refluxed for 8 h. After the reaction was complete (monitored by TLC), the mixture was diluted with ice water and the pH was adjusted to 5–6 with dilute hydrochloric acid. The solution was filtered and recrystallized from methanol to obtain the purified target compound.

[0116] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, 233.3–234.6 °C. 1 H NMR (400 MHz, CDCl3) d 7.38 (dd, J = 5.0, 1.7 Hz, 1H), 7.28 (dd, J = 5.4,1.7 Hz, 1H), 7.20 – 7.17 (m, 1H), 6.84 (s, 1H), 3.89 (s, 3H). 13 C NMR (101 MHz, CDCl3) d : 180.71, 153.33, 140.41, 137.69, 134.26, 127.85, 127.40, 127.01, 103.89, 37.75.

[0117] Example 8

[0118] This embodiment proposes 5-[5-(furan-2-yl)thiophen-2-yl]-1,3,4-oxadiazole-2(3H)-thione (161a). Its synthetic method is as follows:

[0119] 1) Synthesis of ethyl 5-(furan-2-yl)thiophene-2-carboxylate:

[0120]

[0121] Pd[PPh3]4 (0.25 mmol), 2-furanboronic acid (15.00 mmol), ethyl 5-bromothiophene-2-carboxylate (10.00 mmol), and an aqueous solution of Na2CO3 (1 mol / L, 50 mL) were added to a round-bottom flask containing a mixture of 1,4-dioxane and water (10:1, v / v) to obtain a reaction mixture. The reaction mixture was heated to reflux and stirred at reflux temperature for 24 hours. After the reaction was monitored by TLC until complete, 1,4-dioxane was removed by rotary evaporation under reduced pressure to obtain an aqueous phase, which was then extracted with CH2Cl2 (3 × 50 mL), and the organic phase was collected. The obtained organic phase was dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain a concentrated residue. The concentrated residue was purified by silica gel column chromatography (EA / PE = 1:5, v / v) to obtain ethyl 5-(furan-2-yl)thiophene-2-carboxylate.

[0122] 2) Synthesis of 5-(furan-2-yl)thiophene-2-formylhydrazine:

[0123]

[0124] Hydrazine hydrate (10.90 mmol) was slowly added to a methanol (30 mL) solution containing ethyl 5-(furan-2-yl)thiophene-2-carboxylate (3.63 mmol), and the mixture was stirred at reflux for 4 h. After the reaction was complete (monitored by TLC), the crude product precipitate was filtered and purified by washing several times with water to obtain 5-(furan-2-yl)thiophene-2-carboxyhydrazide.

[0125] 3) 5-[5-(furan-2-yl)thiophen-2-yl]-1,3,4-oxadiazole-2(3 H Synthesis of thiophene:

[0126]

[0127] In a 250 mL flask containing 50 mL of methanol, 3.09 mmol of 5-(furan-2-yl)thiophene-2-carboxylhydrazine and 6.18 mmol of potassium hydroxide were added, followed by the slow addition of carbon disulfide (7.72 mmol). The mixture was stirred at room temperature for 30 min, then heated and refluxed for 8 h. After the reaction was complete (monitored by TLC), the mixture was diluted with ice water and the pH was adjusted to 5–6 with dilute hydrochloric acid. The solution was filtered and recrystallized from methanol to obtain the purified target compound.

[0128] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, 268.1–269.2 °C. 1 H NMR (400 MHz, CDCl3) d 7.55 (t, J = 1.4 Hz, 1H), 7.43 (d, J = 6.0 Hz, 1H), 7.31 (d, J = 6.0 Hz, 1H), 6.83 (dd, J = 4.5, 1.7 Hz, 1H), 6.69 (dd, J = 4.6, 1.3Hz, 1H). 13 C NMR (101 MHz, CDCl3) d : 180.90, 153.48, 146.36, 142.15, 133.74, 128.83, 125.85, 125.45, 113.03, 108.12.

[0129] Example 9

[0130] This embodiment proposes 6-[5-(pyridin-2-yl)furan-2-yl]-1,3,4-oxadiazole-2(3 H )-Thione (241a). Its synthesis method is as follows:

[0131] 1) Synthesis of ethyl 5-(pyridin-3-yl)furan-2-carboxylate:

[0132]

[0133] Pd[PPh3]4 (0.25 mmol), 2-pyridineboronic acid (15.00 mmol), ethyl 5-bromo-2-furanocarboxylate (10.00 mmol), and an aqueous solution of Na2CO3 (1 mol / L, 50 mL) were added to a round-bottom flask containing a mixture of 1,4-dioxane and water (10:1, v / v) to obtain a reaction mixture. The reaction mixture was heated to reflux and stirred at reflux temperature for 24 hours. After the reaction was monitored by TLC until complete, 1,4-dioxane was removed by rotary evaporation under reduced pressure to obtain an aqueous phase, which was then extracted with CH2Cl2 (3 × 50 mL), and the organic phase was collected. The obtained organic phase was dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain a concentrated residue. The concentrated residue was purified by silica gel column chromatography (EA / PE = 1:5, v / v) to obtain ethyl 5-(pyridin-3-yl)furan-2-carboxylate.

[0134] 2) Synthesis of 5-(pyridin-2-yl)furan-2-carboxyhydrazide:

[0135]

[0136] Hydrazine hydrate (10.90 mmol) was slowly added to a methanol (30 mL) solution containing ethyl 5-(pyridin-3-yl)furan-2-carboxylate (3.63 mmol), and the mixture was stirred at reflux for 4 h. After the reaction was complete (monitored by TLC), the crude product precipitate was filtered and purified by washing several times with water to obtain 5-(pyridin-2-yl)furan-2-carboxyhydrazide.

[0137] 3) 5-[5-(pyridin-2-yl)furan-2-yl]-1,3,4-oxadiazole-2(3 H Synthesis of thiophene:

[0138]

[0139] In a 250 mL flask containing 50 mL of methanol, 3.09 mmol of 5-(pyridin-2-yl)furan-2-carboxyhydrazide and 6.18 mmol of potassium hydroxide were added, followed by the slow addition of carbon disulfide (7.72 mmol). The mixture was stirred at room temperature for 30 min, then heated and refluxed for 8 h. After the reaction was complete (monitored by TLC), the mixture was diluted with ice water and the pH was adjusted to 5–6 with dilute hydrochloric acid. The solution was filtered and recrystallized from methanol to obtain the purified target compound.

[0140] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, 253.6–254.6 °C. 1 H NMR (400 MHz, CDCl3) d 8.57 (dd, J = 4.0, 1.8 Hz, 1H), 7.82 (ddd, J = 9.0,7.1, 1.7 Hz, 1H), 7.71 (dd, J = 8.9, 1.4 Hz, 1H), 7.31 (d, J = 5.3 Hz, 1H), 7.27 (ddd, J = 7.1, 4.1, 1.4 Hz, 1H), 7.08 (d, J = 5.3 Hz, 1H). 13 C NMR (101 MHz, CDCl3) d : 181.15, 154.05, 153.12, 149.31, 147.99, 139.23, 136.40, 122.87, 119.50, 110.80, 110.37.

[0141] Example 10

[0142] This embodiment proposes 5-[5-(pyrimidin-2-yl)-1 H [-pyrrolo-2-yl]-1,3,4-oxadiazole-2(3 H )-Thione (301a). Its synthesis method is as follows:

[0143] 1) Ethyl-5-(pyrimidin-2-yl)-1 H Synthesis of pyrrole-2-carboxylic acid esters:

[0144]

[0145] Pd[PPh3]4 (0.25 mmol), pyrimidin-2-boronic acid (15.00 mmol), ethyl 5-bromo-1H-pyrrole-2-carboxylate (10.00 mmol), and an aqueous solution of Na2CO3 (1 mol / L, 50 mL) were added to a round-bottom flask containing a mixture of 1,4-dioxane and water (10:1, v / v) to obtain a reaction mixture. The reaction mixture was heated to reflux and stirred at reflux temperature for 24 hours. After the reaction was monitored by TLC until complete, 1,4-dioxane was removed by rotary evaporation under reduced pressure to obtain an aqueous phase, which was then extracted with CH2Cl2 (3 × 50 mL), and the organic phase was collected. The obtained organic phase was dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain a concentrated residue. The concentrated residue was purified by silica gel column chromatography (EA / PE = 1:5, v / v) to give ethyl-5-(pyrimidin-2-yl)-1 H-Pyrrole-2-carboxylic acid ester.

[0146] 2) 5-(pyrimidin-2-yl)-1 H Synthesis of pyrrole-2-formylhydrazide:

[0147]

[0148] Hydrazine hydrate (10.90 mmol) was slowly added to a solution containing ethyl-5-(pyrimidin-2-yl)-1 H The crude product was reacted with 3.63 mmol of pyrrole-2-carboxylic acid ester in 30 mL of methanol and stirred under reflux for 4 h. After the reaction was complete (monitored by TLC), the crude product precipitate was filtered and purified by washing several times with water to give 5-(pyrimidin-2-yl)-1 H -pyrrole-2-formylhydrazide.

[0149] 3) 5-[5-(pyrimidin-2-yl)-1 H [-pyrrolo-2-yl]-1,3,4-oxadiazole-2(3 H Synthesis of thiophene:

[0150]

[0151] In a 250 mL flask containing 50 mL of methanol, add 5-(pyrimidin-2-yl)-1 H 1,2-pyrrole-2-carboxylhydrazine (3.09 mmol) and potassium hydroxide (6.18 mmol) were added, followed by the slow addition of carbon disulfide (7.72 mmol). The mixture was stirred at room temperature for 30 min, then heated and refluxed for 8 h. After the reaction was complete (monitored by TLC), the mixture was diluted with ice water and the pH was adjusted to 5–6 with dilute hydrochloric acid. The solution was filtered and recrystallized from methanol to obtain the purified target compound.

[0152] The melting point, 1H NMR, and 1C NMR data of the synthesized compound are: m. p, 240.8–242.6 °C. 1 H NMR (400 MHz, CDCl3) d : 8.89 – 8.82 (m, 3H), 8.04 (d, J = 7.3 Hz, 1H), 7.34(t, J = 4.0 Hz, 1H). 13 C NMR (101 MHz, CDCl3) d: 180.61, 157.44, 157.23, 152.65, 137.55, 121.12, 119.82, 117.08, 113.97.

[0153] Comparative Example 1

[0154] The comparative compound is derived from patent EP0389426A1, and its structural formula is as follows:

[0155] .

[0156] Application Example 1

[0157] The following components were selected by mass percentage: 60 w / w% of compound 1a proposed in Example 1, 10 w / w% of sodium dodecylbenzenesulfonate, 15 w / w% of sodium lignosulfonate, and the balance being kaolin. These components were mixed and pulverized in a pulverizer until the particle size reached 20 micrometers, yielding a 60% wettable powder. Testing showed that the product conformed to GB / T 16150-1995 standard.

[0158] Application Example 2

[0159] Based on mass percentages, 40 w / w% of compound 21b proposed in Example 4, 14 w / w% of ethoxylated triglyceride, 11 w / w% of PEO-10, and the balance being biodiesel were taken. Compound 21b, PEO-10, and ethoxylated triglyceride were dissolved in the biodiesel, stirred thoroughly, and filtered to obtain a clear solution, i.e., a 40% emulsifiable concentrate. Testing showed that the water content, emulsifying properties, and stability of the obtained emulsifiable concentrate preparation all met the basic requirements for emulsifiable concentrate preparations.

[0160] Application Example 3

[0161] By weight percentage, 30 w / w% of compound 241a proposed in Example 9, 15 w / w% of PEO-10, 10 w / w% of hemicellulose, 10 w / w% of sodium dodecylbenzenesulfonate, and the balance being deionized water were taken. The compounds, 70% of the required water volume, and sodium dodecylbenzenesulfonate were ground in a ball mill. The other components were dissolved in the remaining approximately 30% of the required water volume, stirred, and mixed thoroughly to obtain a 30% aqueous suspension. Testing showed that the prepared product met the basic requirements for a suspension in terms of suspension properties, stability, sustained foaming properties, flowability, and pourability.

[0162] In subsequent applications, all three of the above application examples showed good control effects against fungal and bacterial diseases of plants.

[0163] Experimental Example (I): Test of the fungicidal activity of the compounds synthesized in this invention against various fungal diseases.

[0164] The experimental method is as follows: The compounds from each example or comparative example were dissolved in dimethyl sulfoxide (DMSO) to prepare a stock solution with a concentration of 500 μg / mL. Under aseptic conditions, the prepared 500 μg / mL stock solution was diluted with PDA medium to prepare 50 μg / mL toxicant-containing medium plates, designated as the experimental group. A blank control group without compound treatment was also included. Each experiment was repeated three times. The mycelial growth rate was determined according to the People's Republic of China Agricultural Industry Standard (NY / T 1156.2-2006). Under aseptic conditions, various pathogens were cultured, and mycelial cakes were cut from the edge of the colony using a 7 mm diameter sterile punch. The mycelial cakes were inoculated into the center of the drug-containing plate with the mycelial side down using an inoculator. The plate was then covered and incubated at 26℃. The growth of pathogenic mycelia was investigated based on the growth of colonies in the blank control culture dishes. After the colonies in the blank control had grown sufficiently, the diameter of the colonies in each treatment was measured using the cross-sectional method. The colony growth diameter was calculated using the following formula, and the average value was taken.

[0165] Colony growth diameter = Colony diameter - Mushroom cake diameter

[0166] The results were calculated using the following method: the colony growth diameter of the blank control group (referred to as the control colony growth diameter) and the colony growth diameter of the experimental group treated with the compound (referred to as the experimental colony growth diameter) were used to calculate the mycelial growth inhibition rate of each compound treatment on various pathogens (see the formula below).

[0167] Mycelial growth inhibition rate (%) = [(diameter of colony growth in blank control - diameter of colony growth in experimental control) / diameter of colony growth in blank control] × 100

[0168] Table 1 Results of antifungal activity test

[0169]

[0170] In the table, "-" indicates that the inhibitory activity is less than 20%.

[0171] From the table above, we can see that:

[0172] (1) The thion-type organic compounds proposed in the above embodiments all showed good antibacterial effects against wheat sheath blight pathogen, rapeseed sclerotinia rot pathogen, rice sheath blight pathogen, wheat take-all pathogen, corn stem rot pathogen, and rice blast pathogen. Compared with carbendazim, the effects were similar or even better in some embodiments, indicating that the thion-type organic compounds proposed in this application have good antifungal activity and can be used as fungicides to prevent and control crop diseases caused by fungi and / or bacteria.

[0173] (2) Compared with the compound in Comparative Example 1, compounds 241a and 301a showed higher antibacterial effects against a variety of pathogens and were applicable to the inhibition of more fungal activity (Comparative Example 1 did not show significant activity inhibition against rice blast pathogens). This indicates that compared with aromatic rings, the design of bicyclic heterocycles is more conducive to improving the bactericidal effect of compounds. Furthermore, considering the specific structures of 241a and 301a, it may also be because: the pyridine and pyrimidine rings are "electron-deficient" aromatic heterocycles with uneven electron distribution and multiple sites that can interact strongly and specifically with the target site. Therefore, their biological activity and reactivity are usually much higher than those of a simple aryl group with uniform electron distribution.

[0174] Experimental Example (II): Antibacterial Activity Test of the Compounds Synthesized in this Invention against Various Bacteria

[0175] The detection method is as follows: Compounds from each example or comparative example were dissolved in DMSO to prepare a 1000 μg / mL solution. The turbidity method was used for determination according to the Agricultural Industry Standard of the People's Republic of China (NY / T 1156.2-2006). 9 mL of nutrient broth (NB) medium, 1 mL of the test compound solution (final concentration: 50 μg / mL), and 40 μL of rice bacterial blight or rice blight streak solution were added to a 15 mL test tube. The test tubes were then incubated in a shaker at 180 rpm and 28±1℃ for 12–72 h. The optical density (OD) of the NB medium in each test tube was measured using a microplate reader (model 680, BIO-RAD, Hercules, CA). 595 The experiment continued until the bacteria in the untreated NB medium were in logarithmic growth. A blank control without any treatment was included, and each experiment was repeated three times. The inhibition rate (%) was calculated using the following formula, where C represents the corrected absorbance value (OD) of the untreated NB medium. 595 T represents the processed NB-corrected absorbance value (OD). 595 Inhibition rate (%) = ( C - T ) / C ×100

[0176] Table 2 Results of bacterial activity test

[0177]

[0178] As can be seen from the data in the table, compared with the commonly used fungicide thiabendazole, the compounds in each embodiment showed significantly better inhibitory effects on rice bacterial blight and rice bacterial streak, and some compounds achieved an inhibition rate of 100% against both bacteria, indicating that the compounds proposed in this application have excellent fungicidal activity against rice bacterial blight and rice bacterial streak.

[0179] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A thion-type organic compound, characterized in that, The thionoid organic compounds are selected from one or more of the compounds shown in the following structural formulas and their tautomers: 1a 1b 1c 21b 21c 41a 161a 241a 301a 。 2. A bactericidal composition, characterized in that, Includes the carrier and the thion-type organic compound as described in claim 1.

3. The bactericidal composition according to claim 2, characterized in that, The dosage forms of the bactericidal composition include emulsifiable concentrates, wettable powders, powders, granules, effervescent tablets, suspensions, microemulsions, or water-dispersible granules.

4. The application of a thion-type organic compound as described in claim 1 in the preparation of pesticides, characterized in that, The pesticide is used to control crop diseases caused by fungi and / or bacteria.

5. The application according to claim 4, characterized in that, The fungal type includes at least one of the following: Oomycetes, Basidiomycetes, Zygomycetes, Chytridiomycetes, Ascomycetes, and Deuteromycetes; and / or, The bacteria include at least one of Gram-negative and Gram-positive bacteria. The Gram-negative bacteria include at least one of Erwinia spp., Pectinobacter spp., Diggia spp., Pantotheca spp., Pseudomonas spp., Rhesus spp., Burkholderia spp., Acidophilus spp., Xanthomonas spp., Agrobacterium spp., Micromycetes spp., Phloemobacterium spp., Enterobacter spp., and Lactobacillus spp. The Gram-positive bacteria include at least one of Corynebacterium spp., Streptomyces spp., Bulb spp., Arthrobacter spp., Rhodococcus spp., Bacillus spp., and Lassella spp.

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