Preparation method and application of alkyl aryl ketone compound

Abstract

The application provides a preparation method and application of an alkyl aryl ketone compound. The method uses a 2-alkyl aryl acetonitrile compound as a raw material to prepare the alkyl aryl ketone compound under the action of a transition metal catalyst. Compared with the prior art, the method provided by the application does not need special low temperature and expensive alkali reagents, has high reaction yield, short time, can reduce the alkali consumption, and even in the absence of alkali, the product can be obtained in a high yield, and the three wastes are less.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, specifically relating to a method for preparing alkyl aryl ketone compounds and their applications. Background Technology

[0002] Alkyl aryl ketones are an important class of organic compounds, serving as key intermediates in the preparation of many important agricultural fungicides. For example, 1-(4-chlorophenyl)-2-cyclopropyl-1-propanone is a crucial intermediate in the preparation of the triazole fungicide cyproconazole (CN 103044230), and 4-(4-chlorophenoxy)-2-trifluoromethylacetophenone is a key intermediate in the preparation of the fungicide chlorfluazuron (CN 105152899). The simple and efficient preparation of alkyl aryl ketone compounds is of great significance.

[0003] The conventional method for preparing alkylaryl ketones is the FC acylation reaction. However, this reaction is often limited by the directing effect of substituents and cannot produce all types of products, especially for substrates with electron-withdrawing substituents at the ortho and / or para positions. Furthermore, this method often fails to produce the target product. Additionally, it requires a large amount of metal catalyst (aluminum trichloride), generating significant amounts of wastewater and solid waste.

[0004] Patents (CN107709284, etc.) disclose a method for preparing corresponding arylalkyl ketones by first preparing a Grignard reagent using a halobenzene as a substrate and then reacting it with an acyl halide or acid anhydride, as shown in reaction formula 1. Although this method has a high yield, the Grignard reaction requires harsh conditions such as anhydrous and oxygen-free environments, and it also generates a large amount of metal waste salts, which is not conducive to industrial production. Furthermore, the Grignard reagent has compatibility requirements for the reactant groups; compounds with nitro or ester groups attached to the aromatic ring cannot be prepared by this method.

[0005]

[0006] Watt et al. reported another method for preparing alkylaryl ketones (J. Org. Chem. 1983, 48, 4087-4096). This method uses alkylaryl acetonitrs as raw materials, which are oxidized with oxygen under the action of a base to prepare alkylaryl ketones, as shown in reaction formula 2. This method has low yields (36–60%).

[0007]

[0008] In the process of developing an efficient method for preparing alkylaryl ketones, the inventors, through exploration and experimentation, surprisingly discovered that 2-alkylaryl acetonitrile compounds can be reacted in one step with high yield to obtain the target compound under the action of transition metal catalysts, oxidants and bases, thus avoiding the defects of the aforementioned existing technical solutions. Summary of the Invention

[0009] This invention relates to a novel method for preparing alkylaryl ketone compound I. The novel method for preparing compound I includes: optionally mixing compound II, an oxidizing agent, and a catalyst in the presence of a base, and reacting to obtain compound I, as shown in the following reaction formula:

[0010]

[0011] Among them, R 1 It is a carbon-based group; preferably a C1-C10 alkyl, C6-C12 aryl or a heteroaryl containing one or two atoms selected from nitrogen, oxygen or sulfur; any hydrogen atom on the carbon atom of the alkyl, aryl or heteroaryl can be substituted with a halogen; more preferably a C1-C4 alkyl or a C1-C4 halogen-substituted alkyl.

[0012] R 2 R 3 R 4 R 5 R 6 Independently, each group may be hydrogen, C1-C10 alkyl, C6-C12 aryl, or contain one or two heteroaryl groups selected from nitrogen, oxygen, and sulfur atoms, halogens, nitro groups, cyano groups, C1-C6 alkylacyl groups, C1-C6 alkyloxy groups, C6-C12 aryloxy groups, or -COOR groups. 7 Any hydrogen atom on the carbon atom of the alkyl, aryl, or heteroaryl group can be replaced by a halogen;

[0013] Or, R 2 R 3 R 4 R 5 R 6 Any two adjacent substituents together constitute a C1-C10 cyclic substituent. The carbon atom in the substituent can be replaced by one or two nitrogen, oxygen, or sulfur atoms. Any hydrogen atom on the carbon atom of the cyclic substituent can be replaced by a halogen.

[0014] Furthermore, R 2 R 4 R 6 At least one of them is a haloalkyl, nitro, cyano, halogen, C1-C6 alkylacyl, or -COOR group. 7 .

[0015] R 2 R 4 Independently related to each other are C1-C4 haloalkyl, nitro, cyano, C2-C4 alkylyl, halogen, and -COOR. 7 ;

[0016] R 3 R 5 R6 The components that are independent of each other are hydrogen and C1-C4 alkyl groups;

[0017] R 1 For methyl, R 2 It is trifluoromethyl, R 3 R 5 R 6 Hydrogen is independent of each other; R 4 It is nitro;

[0018] R 7 It is a carbon-based group; preferably a C1-C10 alkyl, a C6-C12 aryl, or a heteroaryl containing one or two atoms selected from nitrogen, oxygen, and sulfur, wherein any hydrogen atom on the carbon atom of the alkyl, aryl, or heteroaryl group can be substituted with a halogen; more preferably a C1-C4 alkyl or a C1-C2 haloalkyl.

[0019] The alkali is an alkali metal carbonate, bicarbonate, phosphate, C1-C6 alkyl carboxylate, formate, hydroxide, alcohol, or hydride; an alkaline earth metal carbonate, bicarbonate, phosphate, C1-C6 alkyl carboxylate, formate, hydroxide, alcohol, or hydride; an alkali metal alkylate or alkali metal aminoate; an organic amine compound; or a mixture of two or more thereof.

[0020] Preferably, they are alkali metal carbonates, phosphates, hydroxides, organic tertiary amine compounds (including substituted or unsubstituted pyridine compounds), and mixtures of two or more of them.

[0021] Further preferred are potassium carbonate, potassium hydroxide, sodium carbonate, sodium hydroxide, alkyl tertiary amine compounds (including cyclic alkyl tertiary amines), and mixtures of two or more thereof; the alkyl group is C1-C12 alkyl, preferably C1-C6 alkyl.

[0022] The oxidant is oxygen, air, ozone, peroxide, hypohalates, halates, perhalates, and mixtures of two or more thereof.

[0023] Peroxides include metal peroxides, hydrogen peroxide, peroxy acid salts, and organic peroxides, such as hydrogen peroxide, sodium peroxide, potassium peroxide, calcium peroxide, magnesium peroxide, zinc peroxide, potassium peroxymonosulfate, strontium peroxide, etc.

[0024] Hypohalates include calcium hypochlorite, lithium hypochlorite, sodium hypochlorite, potassium hypochlorite, etc.

[0025] Halides include sodium chlorate, sodium bromate, potassium iodate, etc.

[0026] Perhalates include ammonium perchlorate, potassium perchlorate, sodium perchlorate, perchloric acid, etc.

[0027] The preferred oxidant is oxygen or air.

[0028] The catalyst is a Group VIII, Group IB, or Group IIB transition element or its cation, or a mixture of two or more thereof. The Group VIII transition elements include iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum; the Group IB transition elements include copper, silver, and gold; and the Group IIB transition elements include zinc, cadmium, and mercury. Preferably, it is a Group VIII or Group IB transition element or its cation, or a mixture of two or more thereof. More preferably, it is metallic copper, metallic iron, metallic copper cation, metallic iron cation, or a mixture of two or more thereof. Particularly preferred are metallic copper, monovalent copper ions, divalent copper ions, or a mixture of two or more thereof. The salts corresponding to the metal cations include halides, halide salts, sulfates, hydrogen sulfates, nitrates, C1-C10 carboxylates, carbonates, phosphates, monohydrogen phosphates, dihydrogen phosphates, pyrophosphates, carbon-based sulfonates, fluoroborates, hydroxides, and oxides of the corresponding metals.

[0029] The molar ratio of compound II to the base is 1:0.001 to 2, preferably 1:0.01 to 0.3, and more preferably 1:0.05 to 0.1.

[0030] The molar ratio of the catalyst to compound II is 0.005 to 2.5:1, preferably 0.008 to 1.0:1, and more preferably 0.01 to 0.1:1.

[0031] The reaction can be carried out in the presence of a solvent. The solvent is a nitrile, ester, haloalkanes, ethers, aromatic hydrocarbons, tertiary amines, amides, sulfones and sulfoxides, water, alcohols, ketones, or mixtures thereof, preferably a mixture of amides, sulfones and sulfoxides, water, or mixtures thereof. More preferably, it is a mixture of N,N-dimethylformamide, N-methylpyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, water, or mixtures thereof.

[0032] The reaction can also be carried out under solvent-free conditions.

[0033] The reaction temperature is -20 to 150 degrees Celsius, preferably 20 to 100 degrees Celsius, and more preferably 50 to 80 degrees Celsius.

[0034] The terms "include," "contain," and "have" used in this document express non-exclusive inclusion. For example, a process or method that includes a series of elements is not necessarily limited to those elements and may also include other elements not explicitly listed.

[0035] Unless explicitly stated otherwise, "or" refers to an inclusive "or" rather than an exclusive "or". For example, the condition A or B means the following possibilities: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0036] A carbonyl group refers to a monovalent group comprising a carbon atom, which is connected to the remainder of the chemical structure via the carbon atom. Carbonyl groups can include any saturated, unsaturated (including aryl), chain-like, cyclic (including polycyclic), and heteroatom moieties. Although there are no particular limitations on the size of carbonyl groups, in the context of this invention, they typically comprise 1 to 16 carbon atoms and 0 to 3 heteroatoms. Important carbonyl groups are selected from C1-C6 alkyl groups, C1-C4 haloalkyl groups, and phenyl groups optionally substituted with 1 to 3 substituents selected from C1-C3 alkyl groups, halogens, and nitro groups.

[0037] In this description, alkyl groups may be straight-chain or branched. The term "halogen," whether alone or in compound terms such as "halogenated alkyl," includes fluorine, chlorine, bromine, or iodine. Furthermore, when used in compound terms such as "halogenated alkyl," the alkyl group may be partially or wholly substituted with the same or different halogen atoms. Examples of "halogenated alkyl" include F3C, ClCH2, CF3CH2, and CF3CCl2.

[0038] This invention also relates to the application of the above method in the preparation of triazole fungicides, wherein the triazole fungicides include, but are not limited to, chlorfluazuron, ipfentrifluconazole, flutriafol, fenbendazole, cyproconazole, furazolidone, difenoconazole, propiconazole, eticonazole, and hexaconazole.

[0039] Compared with existing methods for preparing alkylaryl ketones, the catalytic oxidation method provided by this invention uses a catalytic amount of metal catalyst, avoids the harsh reaction conditions required by existing technologies, does not require special low temperatures (-78 degrees Celsius), and has a high reaction yield.

[0040] Furthermore, when the molar ratio of compound II to the alkali is 1:0.01 to 0.1, the technical solution provided by this invention uses less raw materials, produces less waste, and has a lower overall cost. Detailed Implementation

[0041] The following embodiments further illustrate some features of the present invention, but the scope and content of protection claimed by the present invention are not limited to the following embodiments.

[0042] Example 1: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one (Comparative Experiment)

[0043] To a 50 mL reaction flask, add 1.1 g of potassium carbonate, 2.2 g of water, 1 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, and 10 mL of N,N-dimethylformamide sequentially. Replace with oxygen and place the flask in a 65 °C oil bath under an oxygen atmosphere for 2 h. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 0.4 g of the product, with a yield of 42%. 1 H NMR (CDCl3, 500MHz, TMS): δ8.58 (d, J=1.5Hz, 1H), 8.48 (dd, J1=8.5Hz, J2=1.5Hz, 1H), 7.66 (d, J=8.5Hz, 1H), 2.63 (s, 3H). 13 C NMR (CDCl3, 125MHz): δ 199.8, 148.2, 145.7, 128.5 (q, J = 33Hz), 128.4, 126.9, 122.3 (q, J = 273Hz), 122.3 (q, J = 6Hz), 30.5.

[0044] Example 2: Screening of catalysts for oxidation reaction

[0045] To a 50 mL reaction flask, add 1.1 g of potassium carbonate, 2.2 g of water, 1 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, 10 mL of N,N-dimethylformamide, and 0.05 g of catalyst (Table 1). Replace with oxygen and place the flask in a 65 °C oil bath for 2 h. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain the product. Specific catalysts and reaction results are shown in Table 1.

[0046] Table 1 Catalysts for Oxidation Reactions

[0047] 1 Ferrous chloride 0.6g 63％ 2 Ferric chloride 0.6g 63％ 3 Cuprous chloride 0.9g 94％ 4 Copper chloride 0.8g 84％

[0048] Example 3 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0049] To a 50 mL reaction flask, add 0.1 g of sodium hydroxide, 13 mL of dimethyl sulfoxide, 5 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, and 0.25 g of cuprous chloride sequentially. Place the reaction flask in a 60 °C oil bath and react with air for 24 h. Cool the reaction solution and add it to 100 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 3.8 g of the product, with a yield of 79%.

[0050] Example 4 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0051] To a 50 mL reaction flask, add 0.6 g of sodium carbonate, 25 mL of N,N-dimethylformamide, 10 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, and 0.4 g of cuprous chloride sequentially. Replace with oxygen and place the flask in a 50 °C oil bath, maintaining the temperature for 4 h. After the reaction is complete, cool the reaction solution and add it to 150 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 9.1 g of the product, with a yield of 95%.

[0052] Example 5 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0053] To a 50 mL reaction flask, 10 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, 0.2 g of CuCl, and 25 mL of N,N-dimethylformamide were added sequentially. Oxygen was purged, and the reaction flask was placed in a 65 °C oil bath and heated for 14 h. The reaction solution was then cooled and added to 100 mL of toluene. The resulting mixture was washed, concentrated, and purified to obtain 7.6 g of the product 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a yield of 80%.

[0054] Example 6 Preparation of 5-methyl-2,4-dinitroacetophenone

[0055] 0.5 g of 2-(5-methyl-2,4-dinitrophenyl)propionitrile, 2 mL of N,N-dimethylformamide, 0.1 g of sodium carbonate, 0.8 g of water, and 0.03 g of cuprous chloride were sequentially added to a 50 mL reaction flask. Oxygen was purged, and the reaction mixture was heated to 50 °C and maintained at this temperature for 4 hours. After the reaction was complete, the reaction mixture was cooled and added to toluene (50 mL). The resulting mixture was washed, concentrated, and purified to obtain 0.4 g of 5-methyl-2,4-dinitroacetophenone, with a yield of 84%.

[0056] Example 7 Preparation of 4-acetyl-2-nitroacetophenone

[0057] Add 3.5 mL of N,N-dimethylformamide, 0.7 g of 2-(4-acetyl-2-nitrophenyl)propionitrile, 0.1 g of sodium carbonate, and 10 mg of cuprous chloride sequentially to a 50 mL reaction flask. Replace with oxygen, heat the reaction solution to 80 °C, and maintain this temperature for 2.5 hours. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 0.55 g of 4-acetyl-2-nitroacetophenone, with a yield of 83%. 1 H NMR (CDCl3, 500MHz, TMS): δ8.63 (s, 1H), 8.29 (dd, J1 = 8.0Hz, J2 = 1.0Hz, 1H), 7.55 (d, J = 8.0Hz, 1H), 2.70 (s, 3H), 2.59 (s, 3H).13 C NMR (CDCl3, 125MHz): δ199.0,194.8,145.8,141.3,138.7,133.5,127.8,124.1,30.1,26.7.

[0058] Example 8 Preparation of 2-acetyl-5-nitrobenzene

[0059] To a 50 mL reaction flask, add 7.5 mL of N,N-dimethylformamide, 1.5 g of 2-(1-cyanoethyl)-5-nitrobenzene, 0.1 g of potassium carbonate, and 20 mg of cuprous chloride sequentially. Replace with oxygen, heat the reaction solution to 60 °C, and maintain the temperature for 3 hours. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 1.2 g of 2-acetyl-5-nitrobenzene, in 85% yield.

[0060] Example 9 Preparation of ethyl 2-acetyl-5-nitrobenzoate

[0061] Add 5 mL of N,N-dimethylformamide, 1 g of ethyl 2-(1-cyanoethyl)-5-nitrobenzoate, 0.1 g of potassium carbonate, and 50 mg of cuprous chloride sequentially to a 50 mL reaction flask. Replace with oxygen, heat the reaction solution to 60 °C, and maintain the temperature for 2 hours. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 0.8 g of ethyl 2-acetyl-5-nitrobenzoate, in 84% yield. 1 H NMR (CDCl3, 500MHz, TMS): δ8.29 (d, J=2.5Hz, 1H), 8.08 (dd, J1=9.0Hz, J2=2.5Hz, 1H ), 7.58 (d, J = 9.0Hz, 1H), 4.50 (q, J = 7.0Hz, 2H), 2.37 (s, 3H), 1.47 (t, J = 7.0Hz, 3H). 13 C NMR (CDCl3, 125MHz): δ201.6,164.2,148.8,148.0,129.8,127.2,127.0,125.1,62.5,30.3,13.9.

[0062] Example 10 Preparation of 4-acetyl-3-nitrotrifluorotoluene

[0063] Add 5 mL of N,N-dimethylformamide, 1 g of 4-(1-cyanoethyl)-3-nitrotrifluorotoluene, 0.1 g of potassium carbonate, and 50 mg of cuprous chloride sequentially to a 50 mL reaction flask. Replace with oxygen, heat the reaction solution to 60 °C, and maintain the temperature for 2 hours. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 0.8 g of 4-acetyl-3-nitrotrifluorotoluene, in 84% yield. 1 H NMR (CDCl3, 500MHz, TMS): δ8.38 (s, 1H), 8.02 (d, J = 8Hz, 1H), 7.63 (d, J = 8Hz, 1H), 2.60 (s, 3H).

[0064] Example 11 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)-2-phenylethyl ketone

[0065] To a 50 mL reaction flask, add 7.5 mL of N,N-dimethylformamide, 1.5 g of 2-(4-nitro-2-trifluoromethylphenyl)-3-phenylpropionitrile, 0.2 g of potassium carbonate, 2.6 g of water, and 70 mg of cuprous chloride sequentially. Replace with oxygen, heat the reaction solution to 50 °C, and maintain the temperature for 4 hours. After the reaction is complete, cool the reaction solution and add it to 50 mL of toluene. The resulting mixture is washed, concentrated, and purified to obtain 1.3 g of 1-(4-nitro-2-trifluoromethylphenyl)-2-phenylethyl ketone, in 90% yield.

[0066] Example 12 Preparation of 1-(4-(4-chlorophenoxy)-2-trifluoromethylphenyl)ethyl-1-one

[0067] 0.5 g of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one, 0.3 g of p-chlorophenol, 0.2 g of potassium carbonate, and 2.5 mL of N,N-dimethylformamide were added sequentially to a 25 mL reaction flask. The reaction flask was placed in an oil bath at 125 °C and reacted for 5 h until the reaction was complete. The reaction solution was cooled and added to 50 mL of toluene. The resulting mixture was washed, concentrated, and purified to obtain 0.57 g of the product, with a yield of 85%.

[0068] Example 13 Preparation of Fluopyram

[0069] Add 0.7 g of water and 3.9 g of dimethyl sulfate to a 50 mL three-necked reaction flask. Raise the temperature to 33 °C and add 2.0 g of dimethyl sulfide dropwise. After the addition is complete, continue stirring for 15 minutes. Add 6.3 g of 1-(4-(4-chlorophenoxy)-2-trifluoromethylphenyl)ethyl-1-one prepared according to the method of Example 12 at 35 °C. Add 4.5 g of potassium hydroxide (85% wt) with stirring at 35-45 °C. Then, continue stirring at 38 °C for 2 hours. Sample analysis shows the starting material has disappeared. Add 30 g of water at 60 °C and stir the mixture for 20 minutes. Separate the lower organic product phase and dissolve it in 30 g of DMF. Remove the dimethyl sulfide by distillation to obtain a DMF solution of the product 2-[4-(4-chlorophenoxy)-2-(trifluoromethyl)phenyl]-2-methylethylene oxide, which, by quantitative HPLC analysis, contains 6.6 g of the product, with a yield of 99%.

[0070] The mixture of 6.6 g of 2-[4-(4-chlorophenoxy)-2-(trifluoromethyl)phenyl]-2-methylethylene oxide and 30 g of DMF was heated to 60 °C. Then, 1.7 g (99% wt) of 1,2,4-triazole and 0.3 g of sodium hydroxide powder were added sequentially with stirring. The reaction mixture was heated to 125 °C and stirred at this temperature for 5 hours until the reaction was completed under controlled conditions. Most of the DMF was distilled off under reduced pressure. 30 g of toluene and 20 g of water were added to the concentrated reaction mixture. The aqueous phase was then separated at 60 °C. The toluene phase was washed again with 20 g of water. The aqueous phase was separated, and the toluene solution was concentrated under reduced pressure to a solution containing approximately 50% of the product. The solid was heated to dissolve (approximately 80 °C) and slowly cooled to 0 °C with stirring, and stirred at this temperature for 30 min. The mixture was filtered, and the filter cake was washed twice with 10 g of toluene pre-cooled to 0 °C. The solid was dried to give 6.6 g of fluazinam product, with a yield of 84%.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing compound I, characterized in that: When compound II, an oxidant, and a catalyst are mixed, compound I is obtained by the reaction shown below: Among them, R 1 It is a C1-C10 alkyl group; R 2 For CF3; R 4 It is nitro; R 3 R 5 R 6 It is hydrogen; The catalyst is cuprous chloride; The oxidant is oxygen; The reaction is carried out in the presence of a base, which is an alkali metal carbonate or hydroxide, or an alkaline earth metal carbonate or hydroxide.

2. The method according to claim 1, characterized in that: The alkali mentioned is potassium carbonate, potassium hydroxide, sodium carbonate, or sodium hydroxide.

3. The method according to claim 1, characterized in that: R 1 It is a C1-C4 alkyl group.

4. The method according to claim 1, characterized in that: The molar ratio of compound II to the base is 1:0.001–2; The molar ratio of the catalyst to compound II is 0.005 to 2.

5.

5. The method according to claim 4, characterized in that: The molar ratio of compound II to the base is 1:0.01 to 0.3; the molar ratio of the catalyst to compound II is 0.01 to 0.1:

1.

6. The method according to claim 4, characterized in that: The molar ratio of compound II to the base is 1:0.05~0.

1.

7. The application of the method according to claim 1 in the preparation of triazole fungicides, wherein, The triazole fungicides are chlorfluazuron, ipfentrifluconazole, flutriafol, fenbendazole, cyproconazole, furazolidone, difenoconazole, propiconazole, eticonazole, and hexaconazole.

Images