Preparation method and application of 4-nitro-2-trifluoromethylacetophenone

Abstract

The application provides a method for preparing 4-nitro-2-trifluoromethyl acetophenone and application thereof. The method uses 4-nitro-2-trifluoromethyl halobenzene and 2-cyanopropionic acid ester as raw materials, and reacts to obtain 4-nitro-2-trifluoromethyl acetophenone compound. Compared with the prior art, the method makes the raw material easy to obtain, has high yield, and does not need dangerous process steps.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, specifically relating to a method for preparing 4-nitro-2-trifluoromethylacetophenone and its application. Background Technology

[0002] 4-Nitro-2-trifluoromethylacetophenone is an important organic compound and a key intermediate in the preparation of the fungicide chlorfluazuron (EP3670491A1). A simple and efficient method for preparing this compound is of great significance.

[0003] The compound is prepared by a nucleophilic substitution reaction of 4-nitro-2-trifluoromethylchlorobenzene with nitrobenzene followed by oxidation (EP3670491A1), as shown in reaction formula 1. This method requires the use of the hazardous starting material nitrobenzene, thus greatly limiting its application.

[0004]

[0005] Patents WO2021160468 and WO2021047978 report a nitration reaction of 1-(2-trifluoromethylphenyl)ethanol under mixed acid conditions, followed by a reaction under alkali conditions to obtain the product, as shown in reaction formula 2. This method requires the use of mixed acid, generating a large amount of waste acid; it also requires the use of environmentally unfriendly haloalkane solvents (DCE); the intermediate nitrate ester is a shock-sensitive substance (WO2021047978), posing a significant safety hazard.

[0006]

[0007] Through thought and exploration, the inventors discovered a new method for preparing 4-nitro-2-trifluoromethylacetophenone, which is safer, has a higher yield, and is easier to industrialize. Summary of the Invention

[0008] This invention relates to a novel method for preparing 4-nitro-2-trifluoromethylacetophenone I. The method for preparing compound I includes: a first step of mixing compound II, compound III, and base A to obtain compound IV; a second step of further converting compound IV under the action of base B to obtain compound V; and a third step, optionally in the presence of base C, mixing compound V and an oxidizing agent to obtain compound I, as shown in the following reaction formula:

[0009]

[0010] Among them, X 1 It is a halogen; R 1It is hydrogen, C1-C10 alkyl, C6-C12 aryl, or a heteroaryl group 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; R 1 Preferably, it is hydrogen-, C1-C6 alkyl, or C1-C6 halogen-substituted alkyl; further, R 1 Preferably, it is a C1-C4 alkyl or a C1-C4 halogen-substituted alkyl;

[0011] The bases A, B, and C mentioned above are each independently 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 of these.

[0012] 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.

[0013] 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.

[0014] The oxidant is oxygen, air, ozone, peroxide, hypohalates, halates, perhalates, and mixtures of two or more thereof.

[0015] Peroxides include: metal peroxides, hydrogen peroxide, peroxyates and organic peroxides, such as hydrogen peroxide, sodium peroxide, potassium peroxide, calcium peroxide, magnesium peroxide, zinc peroxide, potassium peroxymonosulfate, strontium peroxide, etc.

[0016] Hypohalates include calcium hypochlorite, lithium hypochlorite, sodium hypochlorite, potassium hypochlorite, etc.

[0017] Halides include sodium chlorate, sodium bromate, potassium iodate, etc.

[0018] Perhalates include ammonium perchlorate, potassium perchlorate, sodium perchlorate, perchloric acid, etc.

[0019] The preferred oxidant is oxygen or air.

[0020] The molar ratio of compound III to compound II is 1.0 to 3.5:1, preferably 1.0 to 2.5:1, and more preferably 1.0 to 2.0:1.

[0021] The molar ratio of compound III to base A is 0.5 to 2.0:1, preferably 0.5 to 1.5:1, and more preferably 0.9 to 1.1:1.

[0022] The molar ratio of compound IV to base B is 0.1 to 2:1, preferably 0.5 to 1.5:1, and more preferably 0.5 to 1.0:1.

[0023] The molar ratio of compound V to base C is 1:0.01 to 3, preferably 1:0.01 to 2, and more preferably 1:0.1 to 2.0.

[0024] The first, second, and third steps can be carried out independently in the presence of a solvent. The solvent is a nitrile, ester, haloalkanes, ethers, aromatic hydrocarbons, tertiary amines, amides, sulfones and sulfoxides, water, alcohols or ketones, or a mixture of the aforementioned substances, preferably a mixture of amides, sulfones and sulfoxides, or the aforementioned substances. More preferably, it is a mixture of dimethylformamide, N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide, or the aforementioned substances.

[0025] The first, second, and third steps can be performed independently under solvent-free conditions.

[0026] The first, second, and third steps can each react independently within a temperature range of -20 to 150 degrees Celsius, preferably 20 to 100 degrees Celsius, more preferably 30 to 80 degrees Celsius, and even more preferably 50 to 80 degrees Celsius.

[0027] In particular, the first step can be carried out in the presence of catalyst A, which is a group VIII or IB or IIB transition element or its cation, and a mixture of two or more of them;

[0028] In particular, the third step can be carried out in the presence of catalyst B; said catalyst B is a group VIII or IB or IIB transition element or its cation, and a mixture of two or more of them.

[0029] 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 and cadmium.

[0030] The catalyst A is preferably a group IB transition element or its cation, particularly preferably metallic copper or monovalent copper ions or divalent copper ions, and mixtures of two or more thereof.

[0031] The molar ratio of catalyst A to compound III is 0.01 to 1.0:1, preferably 0.01 to 0.1:1, and more preferably 0.01 to 0.05:1.

[0032] The catalyst B is preferably a Group VIII or Group IB transition element or its cation, more preferably metallic copper, metallic iron, metallic copper cation, metallic iron cation, or a mixture thereof. Particularly preferred are metallic copper or monovalent copper ions or divalent copper ions, and mixtures 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.

[0033] The molar ratio of catalyst B to compound V is 0.01 to 1.0:1, preferably 0.01 to 0.2:1, and more preferably 0.05 to 0.15:1.

[0034] The method for preparing compound I provided by this invention can also be a one-pot reaction. Compound II, compound III, and base A are mixed and reacted; without further treatment, they are then directly mixed with an oxidizing agent to obtain compound I.

[0035] The method for preparing compound I provided by this invention can also be a one-step reaction. Compound II, compound III, base A, and an oxidizing agent are mixed and reacted in a single step to obtain compound I, as shown in the following reaction formula:

[0036]

[0037] The X 1 R 1 The definitions of base A and oxidizing agent are the same as above.

[0038] The present invention also provides the use of compound IV as a herbicide, which can effectively inhibit the growth of grass and broadleaf weeds, such as black nightshade, lambsquarters, barnyard grass, and millet.

[0039] The present invention also provides an application of the above-mentioned method for preparing compound I: 1-(4-(4-chlorophenoxy)-2-trifluoromethylphenyl)ethyl-1-one is prepared by reacting compound I with p-chlorophenol under the action of base D.

[0040]

[0041] The alkali D is an alkali metal carbonate or an alkaline earth metal carbonate, preferably sodium carbonate or potassium carbonate.

[0042] The terms "include," "contain," and "have" used in this article express non-exclusive inclusion. For example, a process or method that includes a list of elements is not necessarily limited to those elements and may also include other elements not explicitly listed.

[0043] Unless explicitly stated otherwise, "or" refers to an inclusive "or" rather than an exclusive "or". For example, condition A or B means that the following are possible: 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). Mixed chemicals refer to chemicals that come into contact with each other.

[0044] 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.

[0045] Compared with known methods for preparing 4-nitro-2-trifluoromethylacetophenone, the method provided by this invention uses readily available raw materials, avoids dangerous reaction materials and intermediates, is safe to operate, and is easier to carry out industrial production.

[0046] Furthermore, when using a "one-pot" or "one-step" reaction, the method provided by this invention has shorter steps and a simpler process.

[0047] Furthermore, when a transition metal catalyst is added in the third step, the method provided by this invention achieves a higher reaction yield, and the reaction can proceed without the presence of a base, resulting in less waste and lower overall cost.

[0048] It is worth noting that compound IV provided by this invention has bioactivity for weed control. Experiments show that compound IV has herbicidal activity against black nightshade, lambsquarters, barnyard grass, and millet, mainly by inhibiting weed emergence and growth. Detailed Implementation

[0049] 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.

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

[0051] Step 1: Preparation of ethyl 2-(4-nitro-2-trifluoromethylphenyl)-2-cyanopropionate

[0052] 3.4 g of ethyl 2-cyanopropionate, 3.1 g of potassium carbonate, 5 g of 2-trifluoromethyl-4-nitrochlorobenzene, 0.1 g of cuprous chloride, and 20 mL of N,N-dimethylformamide were added sequentially to a 100 mL reaction flask. The reaction flask was placed in an oil bath at 50 °C and heated for 8 h. After the reaction was complete, the reaction solution was cooled and added to 150 mL of toluene. The resulting mixed solution was washed and concentrated to obtain 6.7 g of ethyl 2-(4-nitro-2-trifluoromethylphenyl)-2-cyanopropionate, with a yield of 95%. 1 H NMR (CDCl3, 500MHz, TMS): δ8.62 (d, J=2.0Hz, 1H), 8.50 (dd, J1=9.0Hz, J2=2.0Hz, 1H ), 8.03 (d, J = 9.0Hz, 1H), 4.32 (q, J = 7.0Hz, 2H), 2.22 (s, 3H), 1.31 (t, J = 7.0Hz, 3H). 13 C NMR (CDCl3, 125MHz): δ166.9, 147.7, 139.0, 130.5, 129.9 (q, J = 26Hz), 126. 8,124.0(q,J=4.4Hz),122.7(q,J=218.5Hz),117.6,63.9,46.9,25.1,13.4.

[0053] Step 2: Preparation of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile

[0054] To a 100 mL reaction flask, add 6.7 g of ethyl 2-(4-nitro-2-trifluoromethylphenyl)-2-cyanopropionate, 8.8 g of sodium hydroxide (20% aqueous solution), and 20 mL of tert-butanol. Heat the flask in a 60 °C oil bath for 2 h. After the reaction is complete, cool the reaction solution and add it to 150 mL of toluene. The resulting mixed solution is washed, concentrated, and purified to obtain 5.0 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a yield of 97%. 1 H NMR (CDCl3, 500MHz, TMS): δ 8.58 (d, J = 2Hz, 1H), 8.51 (dd, J1 = 8.5Hz, J2 = 2Hz, 1H), 8.00 (d, J = 8.5Hz, 1H), 4.38 (q, J = 7Hz, 1H), 1.72 (d, J = 7Hz, 3H). 13 C NMR (CDCl3, 125MHz): δ147.3, 142.9, 131.0, 129.1 (q, J = 33Hz), 127.6, 122.6 (q, J = 273Hz), 122.1 (q, J = 5Hz), 119.9, 28.1, 21.9.

[0055] Step 3: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0056] 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 prepared in step 2 above, and 10 mL of N,N-dimethylformamide. Displace the oxygen and place the reaction flask in a 60 °C oil bath for 2 h. After the reaction is complete, cool the reaction solution and add it to 80 mL of toluene. The resulting mixed solution is washed, concentrated, and purified to obtain 0.4 g of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one, 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.

[0057] Example 2: Screening of catalysts for oxidation reaction

[0058] Step 1: Preparation of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile

[0059] 5.1 g of ethyl 2-cyanopropionate, 5.5 g of potassium carbonate, 5 g of 2-trifluoromethyl-4-nitrochlorobenzene, and 20 mL of N,N-dimethylformamide were added sequentially to a 100 mL reaction flask. The reaction flask was placed in an oil bath at 65 °C and heated for 6 h. After the reaction was complete, the reaction solution was cooled and added to 150 mL of toluene. The resulting mixed solution was washed, concentrated, and purified to obtain 8.4 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a reaction yield of 86%.

[0060] Step 2: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0061] To a 50 mL reaction flask, add 1.1 g potassium carbonate, 2.2 g water, 1 g 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, 10 mL N,N-dimethylformamide, and 0.05 g of the catalyst listed in Table 1, 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 toluene. The resulting mixture is washed, concentrated, and purified to obtain the product. Specific catalysts and reaction results are shown in Table 1.

[0062] Table 1 Catalysts for Oxidation Reactions

[0063] No. Catalyst Product weight Reaction yield 1 Ferrous chloride 0.6g 63％ 2 Ferric chloride 0.6g 63％ 3 Cuprous chloride 0.9g 94％ 4 Copper chloride 0.8g 84％

[0064] Example 3 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0065] Step 1: Preparation of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile

[0066] 51 g of ethyl 2-cyanopropionate, 50 g of 2-trifluoromethyl-4-nitrochlorobenzene, 55 g of potassium carbonate, 4.9 g of triethylenediamine, and 200 mL of N,N-dimethylformamide were added sequentially to a 100 mL reaction flask. The reaction flask was placed in an 80 °C oil bath and heated for 13 h. The reaction solution was concentrated, cooled, and added to 100 mL of toluene. The resulting mixture was washed, concentrated, and purified to obtain 53 g of the product 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a reaction yield of 98%.

[0067] Step 2: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0068] To a 50 mL reaction flask, add 0.4 g of sodium hydroxide, 10 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, 0.3 g of CuCl, and 25 mL of dimethyl sulfoxide sequentially. Replace with oxygen and place the flask in a 65 °C oil bath, heating for 4 h. Cool the reaction mixture and add it to 100 mL of toluene. Wash, concentrate, and purify the resulting mixture to obtain 8.7 g of the product 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one, with a yield of 91%.

[0069] Example 4 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0070] Step 1: Preparation of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile

[0071] To a 100 mL reaction flask, 4.2 g of ethyl 2-cyanopropionate, 2.7 g of sodium acetate, 5 g of 2-trifluoromethyl-4-nitrochlorobenzene, and 10 mL of dimethyl sulfoxide were added sequentially. The reaction flask was placed in an oil bath at 50 °C and heated for 5 h until the reaction was complete. The reaction solution was cooled and added to 100 mL of toluene. After washing, concentration, and purification, the mixture yielded 3.5 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a yield of 65%.

[0072] Step 2: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0073] To a 50 mL reaction flask, 3.5 g of compound 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, 0.1 g of cuprous chloride, and 10 mL of N,N-dimethylformamide were added sequentially. The reaction flask was placed in an 80 °C oil bath, and 2.0 g (30% wt) of hydrogen peroxide was added dropwise with stirring. After the addition was complete, stirring was continued for 4 h. Once 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 1.6 g of the product, with a yield of 48%.

[0074] Example 5 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0075] Step 1: Preparation of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile

[0076] 5.6 g of ethyl 2-cyanopropionate, 4.7 g of sodium carbonate, 5 g of 2-trifluoromethyl-4-nitrochlorobenzene, and 10 mL of N-methylpyrrolidone were added sequentially to a 100 mL reaction flask. The reaction flask was placed in an oil bath at 50 °C and heated for 5 h until the reaction was complete. The reaction solution was cooled and added to 100 mL of toluene. The mixture was washed, concentrated, and purified to obtain 5 g of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a reaction yield of 92%.

[0077] Step 2: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0078] 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%.

[0079] Example 6 Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0080] Step 1: Preparation of 2-(4-nitro-2-trifluoromethylphenyl)propionitrile

[0081] 51 g of ethyl 2-cyanopropionate, 50 g of 2-trifluoromethyl-4-nitrochlorobenzene, 55 g of potassium carbonate, 4.9 g of triethylenediamine, and 200 mL of N,N-dimethylformamide were added sequentially to a 100 mL reaction flask. The reaction flask was placed in an 80 °C oil bath and heated for 13 h. The reaction solution was concentrated, cooled, and added to 100 mL of toluene. The resulting mixture was washed, concentrated, and purified to obtain 53 g of the product 2-(4-nitro-2-trifluoromethylphenyl)propionitrile, with a reaction yield of 98%.

[0082] Step 2: Preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0083] 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. The mixture was purged with oxygen, and the 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 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one, with a yield of 80%.

[0084] Example 7: One-pot preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0085] Add 5.1 g of ethyl 2-cyanopropionate, 5.5 g of potassium carbonate, 5 g of 2-trifluoromethyl-4-nitrochlorobenzene, and 20 mL of N,N-dimethylformamide sequentially to a 100 mL reaction flask. Place the reaction flask in a 60 °C oil bath and heat for 6 h until the reaction is complete. Then add 3.1 g of potassium carbonate and 0.1 mg of CuCl to the reaction flask. Replace with oxygen and place the reaction flask in a 65 °C oil bath for 2 h. Once the reaction is complete, cool the reaction solution and add it to 150 mL of toluene. The resulting mixture was washed, concentrated, and purified to obtain 4.9 g of the product, with a yield of 95%.

[0086] Example 8: One-step preparation of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one

[0087] Add 5.6 g of ethyl 2-cyanopropionate, 9.2 g of potassium carbonate, 5 g of 2-trifluoromethyl-4-nitrochlorobenzene, 20 mL of N,N-dimethylformamide, and 0.5 mg of CuCl to a 100 mL reaction flask sequentially. Displace the oxygen and place the reaction flask in a 65 °C oil bath, heating for 7 h. Cool the reaction mixture and add it to 150 mL of toluene. Wash, concentrate, and purify the resulting mixture to obtain 3.1 g of 1-(4-nitro-2-trifluoromethylphenyl)ethyl-1-one, with a yield of 60%.

[0088] Example 9 Preparation of 1-(4-(4-chlorophenoxy)-2-trifluoromethylphenyl)ethyl-1-one

[0089] 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%.

[0090] Example 10 Preparation of Fluopyram

[0091] 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 9 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 that 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%.

[0092] 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%.

[0093] Example 11 Pharmacodynamic Test

[0094] Test standard: NYT 1155.1-2006 Guidelines for Indoor Bioassay Testing of Pesticides - Herbicides - Part 1: Plate Method for Activity Testing.

[0095] Experimental targets: barnyard grass (Echinochloa crusgalli (L.) Beauv.), millet (Panicum acroanthum Steud.), black nightshade (Solanum nigrum L.), and quinoa (Chenopodium album L.).

[0096] Test reagent: Ethyl 2-(4-nitro-2-trifluoromethylphenyl)-2-cyanopropionate prepared by the method in Example 1;

[0097] Weigh out the drug and dissolve it in DMF to make a stock solution. Then weigh out different amounts of the stock solution and dilute it in water to prepare different doses of the drug solution.

[0098] Experimental method: Petri dish assay. One test agent, one control (CK) (water control), and four targets were used, with two replicates for each treatment. Two sheets of filter paper were placed in a 9cm diameter petri dish. 8mL of the prepared drug solution at different concentrations was added, followed by 10 uniformly distributed weed seeds. After application, each treatment was placed in an incubator (light / dark settings: 30℃ / 25℃, 12h light / 12h darkness). The growth status of the targets was observed and recorded periodically. Approximately 7 days after application, the overall plant growth inhibition rate of each treatment was visually assessed compared to the CK. The number of seedlings, stem length, and root length were also measured. The percentage of growth inhibition for seedlings, stem length, and root length was calculated by comparing with the CK. The results are shown in Table 2-5.

[0099] Table 2 Results of the herbicidal activity assay of Solanum nigrum (7 days after application - inhibition rate %)

[0100]

[0101] Table 3. Results of the herbicidal activity assay for lambsquarters (7 days after application - inhibition rate %)

[0102]

[0103] Table 4. Results of the herbicidal activity assay of millet (7 days after application - inhibition rate %)

[0104]

[0105] Table 5 Results of barnyardgrass herbicidal activity assay (7 days after application - inhibition rate %)

[0106]

[0107] 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 process for the preparation of compound I, characterized in that, The method comprises: a first step of mixing compound II, compound III and base A to obtain compound IV; a second step of further converting compound IV under the action of base B to obtain compound V; and a third step of mixing compound V and an oxidizing agent to obtain compound I, and the reaction formula is as follows: wherein X 1 is halogen; R 1 is C1-C10 alkyl; The base A is a carbonate, bicarbonate, phosphate, C1-C6 alkyl carboxylate, hydroxide, alcoholate or hydride of an alkali metal, a C1-C6 alkyl carboxylate, hydroxide or hydride of an alkaline earth metal, an organic amine compound, and a mixture of two or more thereof. The base B is a carbonate of an alkali metal or an alkaline earth metal, a hydroxide of an alkali metal or an alkaline earth metal, an organic amine compound, and a mixture of two or more thereof. The organic amine compound is a tertiary alkyl amine compound or pyridine, and the alkyl group is C1-C6 alkyl. The oxidizing agent is oxygen, air, a peroxide, and a mixture of two or more thereof; and the peroxide is hydrogen peroxide, sodium peroxide, potassium peroxide, calcium peroxide, magnesium peroxide, zinc peroxide, potassium peroxomonosulfate or strontium peroxide.

2. The method of claim 1, wherein: The base A and the base B are independently potassium carbonate, potassium hydroxide, sodium carbonate or sodium hydroxide, and a mixture of two or more thereof; and the oxidizing agent is oxygen or air.

3. The method of claim 1, wherein: The method for preparing compound I can also be a "one-pot method" reaction using compound II, compound III, an oxidizing agent, base A and / or base B as raw materials.

4. The method of claim 1, wherein: Compound II, compound III, base A and an oxidizing agent are directly mixed to prepare compound I, and the reaction formula is as follows: wherein X 1 , R 1 , base A, oxidizing agent are as defined in claim 1.

5. The method of claim 1, wherein: The first step is performed in the presence of catalyst A, and the third step is performed in the presence of catalyst B; the catalyst A is metallic copper, a univalent copper ion or a divalent copper ion, and a mixture of two or more thereof; and the catalyst B is metallic copper, metallic iron, a copper cation or an iron cation, or a mixture thereof.

6. The method of claim 5, wherein: The catalyst B is metallic copper, a univalent copper ion or a divalent copper ion, and a mixture of two or more thereof.

7. A compound IV having the following structural formula: wherein R 1 is C1-C10alkyl, any of the hydrogen atoms on the carbon atoms of which alkyl group can be replaced by halogen.

8. The compound IV according to claim 7, characterized in that, The R 1 It is a C1-C4 alkyl or a C1-C4 halogen-substituted alkyl.

9. Use of a compound according to claim 8, characterized in that, The compound IV is used for controlling Solanum nigrum, Chenopodium glaucum, Echinochloa crus-galli and Panicum miliaceum.

10. Use of the process for the preparation of Compound I according to claim 1, characterized in that, Compound I is reacted with p-chlorophenol in the presence of base D to prepare 1-(4-(4-chlorophenoxy)-2-trifluoromethylphenyl)ethyl-1-ketone, and the reaction formula is as follows: The base D is a carbonate of an alkali metal or an alkaline earth metal.

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