A method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole

Abstract

The invention discloses a method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) pyrazole by trifluoromethylaniline, including: trifluoromethylaniline is reacted with dilute hydrochloric acid and hydrogen peroxide, and chlorination generates 2,6-dichloro-4-trifluoromethylaniline; 2,6-dichloro-4-trifluoromethylaniline is diazotized with nitrosyl chloride under acidic conditions to generate diazonium chloride; diazonium chloride is condensed with ethyl 2,3-dicyanopropionate under acidic conditions, and after hydrolysis, the hydrolysis organic phase is cyclized under the catalytic action of ammonia water or ammonia gas to generate 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) pyrazole; the hydrolysis aqueous phase is adsorbed by a weakly basic anion exchange resin to obtain a dilute hydrochloric acid solution, which can be used as a chlorination reagent for recycling and chlorination reaction. The method not only avoids the treatment of a large amount of waste salt, but also can recycle the diazotization byproduct, greatly saving the usage of the chlorination reagent.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical engineering, and specifically relates to a method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole. Background Art

[0002] 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole is abbreviated as pyrazole ring, molecular formula C 11 H5Cl2F3N4 is an important intermediate in the synthesis of insecticides fipronil and ethiprole. The pure product is a white crystalline solid, and the industrial product is a light yellow-brown solid with a melting point of 141-142°C. It is soluble in methanol, ethanol, acetone, ethylene dichloride and ethyl acetate.

[0003] Chinese patents CN103396366A and CN110240566A disclose a method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, which uses 2,6-dichloro-4-trifluoromethylaniline as a raw material, sulfuric acid as a reaction medium, and drips an aqueous solution of sodium nitrite to obtain a diazonium salt solution of 2,6-dichloro-4-trifluoromethylaniline through a diazotization reaction, then adds ethyl 2,3-dicyanopropionate to react, and then cyclizes in an organic solvent under weak alkaline conditions to generate 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole. The patent reaction produces a large amount of waste acid, and the "three wastes" are difficult to treat and have a low yield.

[0004] Chinese patent CN106220565A discloses a method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, using 2,6-dichloro-4-trifluoromethylaniline as a raw material, nitrosylsulfuric acid as a diazotizing agent, adding ethyl 2,3-dicyanopropionate to react, and then cyclizing in an organic solvent under weak alkaline conditions to generate 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole. Although this method avoids the use of sodium nitrite, it still needs to deal with a large amount of sulfuric acid byproducts.

[0005] The above prior art has the following disadvantages:

[0006] 1. In the prior art, in the process of synthesizing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, the diazotization process mostly uses sodium nitrite and concentrated sulfuric acid to prepare nitrous acid. Since sodium nitrite introduces sodium ions, the reaction solution is a mixed solution containing a large amount of sodium sulfate, sulfuric acid and acetic acid. This part of the wastewater still requires a large amount of liquid alkali to neutralize the excess acid to generate mixed salt, and finally desalt by evaporation. This process is not only difficult to handle, but also causes a large amount of waste of raw materials and energy.

[0007] 2. In the prior art process for synthesizing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, nitrosylsulfuric acid is used in the diazotization process to replace sodium nitrite, thereby avoiding the formation of sodium salt. However, nitrosylsulfuric acid will generate sulfuric acid to form a mixed acid system of sulfuric acid and acetic acid, which is not only difficult to handle, but also sulfuric acid cannot be used in this process. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole. The invention has the following advantages: first, nitrosyl chloride is used to replace sodium nitrite in the diazotization process to avoid the production of sodium salt, thereby fundamentally reducing the difficulty of treating wastewater; second, the raw materials and products of the chlorination section and the diazotization section are organically combined, and the hydrochloric acid produced in the diazotization section is effectively separated and returned to the chlorination section as a raw material, which not only reduces the treatment of waste acid, but also saves the cost of raw materials.

[0009] The present invention is achieved through the following technical solutions:

[0010] A method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole comprises the following steps:

[0011] Step 1, chlorination: trifluoromethylaniline, dilute hydrochloric acid and hydrogen peroxide are subjected to a chlorination reaction at a temperature of 40 to 50° C. to obtain 2,6-dichloro-4-trifluoromethylaniline, wherein the molar ratio of trifluoromethylaniline, dilute hydrochloric acid and hydrogen peroxide is 1:(3 to 4):(2.0 to 2.1); the chlorination reaction solution is allowed to stand for stratification, and the lower chlorination reaction organic phase is taken and entered into step 2 for diazotization;

[0012] Step 2, diazotization: add acetic acid and nitrosyl chloride to the organic phase of the chlorination reaction obtained in step 1, react at a temperature of 10 to 20° C. to obtain 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride, wherein the molar ratio of 2,6-dichloro-4-trifluoromethylaniline to nitrosyl chloride is 1:(1 to 1.05); the diazotization reaction product enters step 3;

[0013] Step 3, condensation: add ethyl 2,3-dicyanopropionate and acetic acid to the diazotization reaction product, and carry out condensation reaction at a temperature of 20 to 35° C. to obtain ethyl 2,3-dicyano-2-(2,6-dichloro-trifluoromethylphenylazo)propionate; the molar ratio of 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride to ethyl 2,3-dicyanopropionate is 1:(1 to 1.1); the condensation reaction product enters step 4;

[0014] Step 4, hydrolysis: adding water to the condensation reaction product to perform hydrolysis, allowing the hydrolyzed product to stand and separate into layers, the aqueous phase of the hydrolyzed product entering step 6, and the organic phase of the hydrolyzed product entering step 5; the mass ratio of the condensation reaction product to the added water is 1:0.5-0.7;

[0015] The aqueous phase of the hydrolyzate is an acidic aqueous phase containing hydrochloric acid and acetic acid;

[0016] The organic phase of the hydrolyzate is an organic phase containing cyanoazo compounds;

[0017] Step 5, cyclization: adding ammonia water or ammonia gas to the organic phase of the hydrolyzate to cause a cyclization reaction at a temperature of 20 to 40° C. to obtain a cyclization reaction product, and the cyclization reaction product enters step 7;

[0018] Step 6, adsorption: adding a weakly basic ion exchange resin to the aqueous phase of the hydrolyzate to adsorb acetic acid in the aqueous phase of the hydrolyzate, and recycling the aqueous phase of the hydrolyzate after adsorption to step 1;

[0019] The saturated weakly basic ion exchange resin is heated to 120-130° C. to desorb the acetic acid adsorbed on the weakly basic ion exchange resin. The desorbed acetic acid is recovered by condensation and returned to step 2 and / or step 3.

[0020] Due to the difference in polarity between acetic acid and hydrochloric acid, acetic acid is adsorbed in the resin and the aqueous phase after adsorption is a dilute hydrochloric acid solution, which can be recycled back to step 1 for chlorination;

[0021] Step 7, purification: adding toluene to the cyclization reaction product, cooling and crystallizing, the cooling rate is 1 to 4°C / h, the cooling end temperature is 0 to 10°C, and the crystalline solid is dried to obtain a refined product of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole.

[0022] Toluene can be used as a solvent to dissolve the crude product, and then the cooling and crystallization process can further purify the product. The toluene of the resulting crystalline product is evaporated during the drying process and will not remain in the final product.

[0023] In the above technical solution, in step 1, the concentration of the hydrochloric acid solution is 15-16wt%, and the concentration of the hydrogen peroxide is 27.0-28.0wt%.

[0024] In the above technical solution, in step 4, the hydrolysis reaction time is 1 to 2 hours, and the reaction temperature is room temperature.

[0025] In step 5 described in the above technical solution, the concentration of ammonia water is 20-25wt%.

[0026] In the above technical solution, in step 6, the temperature of the saturated weak alkaline ion exchange resin is raised to 120-130 degrees Celsius, and the acetic acid adsorbed on the weak alkaline ion exchange resin is desorbed. The desorbed acetic acid is recovered by condensation and returned to step 2 and / or step 3.

[0027] In the above technical solution, the ion exchange resin in step 6 is a weak base ion exchange resin, preferably A-654 macroporous weak base anion exchange resin or HPA-330 epoxy weak base anion exchange resin.

[0028] In the above technical solution, the acetic acid added in step 2 and step 3 is mainly used as a solvent and does not participate in the reaction.

[0029] The advantages and beneficial effects of the present invention are:

[0030] 1. 2,6-Dichloro-p-trifluoromethylaniline and nitrosyl chloride are diazotized under the action of dilute hydrochloric acid. Nitrosyl chloride, as an active substance, not only has a fast reaction speed, but also produces HCl which can be dissolved in dilute hydrochloric acid. No other impurity ions are introduced in the reaction, especially no sodium ions are introduced to form sodium salt.

[0031] 2. Reuse of wastewater from diazotization condensation reaction. After the condensation reaction, a large amount of acidic wastewater of dilute hydrochloric acid and organic acid is produced. The acidic wastewater is treated by ion exchange absorption and extraction, and the obtained dilute hydrochloric acid can be returned to the process as a reactant for the chlorination reaction.

[0032] Compared with the traditional production method, the method disclosed by the present invention avoids the treatment of a large amount of waste acid and waste salt, and the hydrochloric acid generated by the diazotization reaction can be recycled as a chlorination reagent in the chlorination reaction; while greatly reducing the wastewater treatment, it also reduces the consumption of raw materials. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments.

[0034] Example 1

[0035] A method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole comprises the following steps:

[0036] Step 1, chlorination: add 20.0g of p-trifluoromethylaniline, 87.6g of 15.5wt% dilute hydrochloric acid, and 30.7g of 27.5wt% hydrogen peroxide into a chlorination kettle, and react at 40-43°C for 2h; the chlorination reaction solution is allowed to stand for stratification, and the lower chlorination reaction organic phase is taken and entered into step 2 for diazotization; the organic phase is 2,6-dichloro-p-trifluoromethylaniline, weighing 28.6g;

[0037] Step 2, diazotization: add 23.9 g of acetic acid to the organic phase of the chlorination reaction obtained in step 1, introduce 8.1 g of nitrosyl chloride gas, and react at 10-15° C. for 5 h to obtain 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride; the diazotization reaction product enters step 3;

[0038] Step 3, condensation: add 19.0 g of ethyl 2,3-dicyanopropionate and 17.4 g of acetic acid to the diazotization reaction product, react at 20-25° C. for 3 h, and obtain 97.0 g of a condensation product, wherein the condensation product is mainly ethyl 2,3-dicyano-2-(2,6-dichloro-trifluoromethylphenylazo)propionate; the condensation reaction product enters step 4;

[0039] Step 4, hydrolysis: add 25 g of water to the condensation reaction product, hydrolyze at 20-25° C. for 1 h, then stand for stratification to obtain 70.8 g of aqueous phase layer and 51.2 g of organic phase layer. The aqueous phase of the hydrolyzate enters step 6, and the organic phase of the hydrolyzate enters step 5;

[0040] The aqueous phase of the hydrolyzate is an acidic aqueous phase containing hydrochloric acid and acetic acid;

[0041] The organic phase of the hydrolyzate is an organic phase containing cyanoazo compounds;

[0042] Step 5, cyclization: 3 g of ammonia gas was introduced into the organic phase of the hydrolyzate, and the reaction was carried out at 20-25° C. for 1 h to obtain 54.2 g of cyclization product; and step 7 was performed for purification;

[0043] Step 6, adsorption: the aqueous phase of the hydrolyzate is placed in an adsorption column filled with A-654 macroporous weak base anion exchange resin, and adsorbed at room temperature for 1 hour to adsorb acetic acid in the aqueous phase of the hydrolyzate. After adsorption, the liquid is 29.2g of 15.5wt% hydrochloric acid; the hydrochloric acid can be recycled to the chlorination step;

[0044] The saturated weakly basic ion exchange resin is heated to 125-130 degrees, and the acetic acid adsorbed on the weakly basic ion exchange resin is desorbed. The desorbed acetic acid is recovered by condensation and returned to step 2 and / or step 3;

[0045] Step 7, purification: add 100.0 g of toluene to the cyclization product of step 5, let stand to separate, discard the aqueous layer, cool the organic layer to 5°C at a cooling rate of 2-3°C / h, filter, and dry the filter cake to obtain 37.6 g of a refined product of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole.

[0046] Embodiment 2:

[0047] A method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole comprises the following steps:

[0048] Step 1, chlorination: add 20.2 g of p-trifluoromethylaniline, 29.2 g of dilute hydrochloric acid obtained in step 6 of Example 1, 58.4 g of fresh 15.4 wt% hydrochloric acid, and 31.9 g of 27.3 wt% hydrogen peroxide into a chlorination kettle, and react at 43-46° C. for 2 h; the chlorination reaction solution is allowed to stand for stratification, and the lower chlorination reaction organic phase is taken and entered into step 2 for diazotization; the organic phase is 2,6-dichloro-p-trifluoromethylaniline, which is weighed to obtain 28.9 g;

[0049] Step 2, diazotization: add 24 g of acetic acid to the organic phase of the chlorination reaction obtained in step 1, introduce 8.2 g of nitrosyl chloride gas, and react at 12-15° C. for 5 h to obtain 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride; the diazotization reaction product enters step 3;

[0050] Step 3, condensation: add 19.1 g of ethyl 2,3-dicyanopropionate and 17.5 g of acetic acid to the diazotization reaction product, react at 25-28° C. for 3 h, and obtain 97.7 g of a condensation product, which is mainly ethyl 2,3-dicyano-2-(2,6-dichloro-trifluoromethylphenylazo)propionate; the condensation reaction product enters step 4;

[0051] Step 4, hydrolysis: add 25.2 g of water to the condensation reaction product, hydrolyze at 22-25° C. for 1 h, then stand for stratification to obtain 71.0 g of aqueous phase layer and 51.9 g of organic phase layer. The aqueous phase of the hydrolyzate enters step 6, and the organic phase of the hydrolyzate enters step 5;

[0052] The aqueous phase of the hydrolyzate is an acidic aqueous phase containing hydrochloric acid and acetic acid;

[0053] The organic phase of the hydrolyzate is an organic phase containing cyanoazo compounds;

[0054] Step 5, cyclization: add 15.1 g of 20 wt% ammonia water to the organic phase of the hydrolyzate, react at 20-25° C. for 1 h, to obtain 67.0 g of cyclization product; go to step 7 for refining;

[0055] Step 6, adsorption: placing the aqueous phase of the hydrolyzate in an adsorption column filled with HPA-330 epoxy weakly basic anion exchange resin, adsorbing at room temperature for 1 hour, adsorbing acetic acid in the aqueous phase of the hydrolyzate, and the liquid after adsorption is 29.8g of 15.4wt% hydrochloric acid; the hydrochloric acid can be recycled to the chlorination step;

[0056] The saturated weakly basic ion exchange resin is heated to 125-130 degrees, and the acetic acid adsorbed on the weakly basic ion exchange resin is desorbed. The desorbed acetic acid is recovered by condensation and returned to step 2 and / or step 3;

[0057] Step 7, purification: add 101.0 g of toluene to the cyclization product of step 5, let stand to separate, discard the aqueous layer, cool the organic layer to 5°C at a cooling rate of 2-3°C / h, filter, and dry the filter cake to obtain 37.3 g of a refined product of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole.

[0058] Embodiment 3:

[0059] A method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole comprises the following steps:

[0060] Step 1, chlorination: add 20.1g of p-trifluoromethylaniline, 29.8g of dilute hydrochloric acid obtained in step 6 of Example 2, 58.2g of fresh 15.4wt% hydrochloric acid, and 31.0g of 27.5wt% hydrogen peroxide into a chlorination kettle, and react at 40-43°C for 2h; the chlorination reaction solution is allowed to stand for stratification, and the lower chlorination reaction organic phase is taken and entered into step 2 for diazotization; the organic phase is 2,6-dichloro-p-trifluoromethylaniline, which is weighed to obtain 28.7g;

[0061] Step 2, diazotization: add 23.6 g of acetic acid to the organic phase of the chlorination reaction obtained in step 1, introduce 8.1 g of nitrosyl chloride gas, and react at 12-15° C. for 5 h to obtain 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride; the diazotization reaction product enters step 3;

[0062] Step 3, condensation: add 19.0 g of ethyl 2,3-dicyanopropionate and 17.5 g of acetic acid to the diazotization reaction product, react at 25-28° C. for 3 h, and obtain 96.9 g of a condensation product, which is mainly ethyl 2,3-dicyano-2-(2,6-dichloro-trifluoromethylphenylazo)propionate; the condensation reaction product enters step 4;

[0063] Step 4, hydrolysis: add 25.1 g of water to the condensation reaction product, hydrolyze at 21-25° C. for 1 h, then stand for stratification to obtain 70.2 g of aqueous phase layer and 51.8 g of organic phase layer. The aqueous phase of the hydrolyzate enters step 6, and the organic phase of the hydrolyzate enters step 5;

[0064] The aqueous phase of the hydrolyzate is an acidic aqueous phase containing hydrochloric acid and acetic acid;

[0065] The organic phase of the hydrolyzate is an organic phase containing cyanoazo compounds;

[0066] Step 5, cyclization: add 13.5 g of 25 wt% ammonia water to the organic phase of the hydrolyzate, react at 20-25° C. for 1 h, and obtain 65.3 g of cyclization product; go to step 7 for refining;

[0067] Step 6, adsorption: placing the aqueous phase of the hydrolyzate in an adsorption column filled with A-654 macroporous weak base anion exchange resin, adsorbing at room temperature for 1 hour, adsorbing acetic acid in the aqueous phase of the hydrolyzate, and the liquid after adsorption is 29.4g of 15.5wt% hydrochloric acid; the hydrochloric acid can be recycled to the chlorination step;

[0068] The saturated weakly basic ion exchange resin is heated to 122-125 degrees Celsius to desorb the acetic acid adsorbed on the weakly basic ion exchange resin. The desorbed acetic acid is recovered by condensation and returned to step 2 and / or step 3.

[0069] Step 7, purification: add 100.5 g of toluene to the cyclization product of step 5, let stand for stratification, discard the aqueous layer, cool the organic layer to 5 ° C at a cooling rate of 2-3 ° C / h, filter, and dry the filter cake to obtain 36.6 g of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole refined product.

[0070] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, characterized in that: The following steps are involved: Step 1, chlorination: trifluoromethylaniline, dilute hydrochloric acid and hydrogen peroxide are subjected to a chlorination reaction at a temperature of 40-50°C to obtain 2,6-dichloro-4-trifluoromethylaniline, wherein the molar ratio of trifluoromethylaniline, dilute hydrochloric acid and hydrogen peroxide is 1:(3-4):(2.0-2.1); the chlorination reaction solution is allowed to stand for stratification, and the lower chlorination reaction organic phase is taken and entered into step 2 for diazotization; Step 2, diazotization: add acetic acid and nitrosyl chloride to the organic phase of the chlorination reaction obtained in step 1, react at a temperature of 10-20° C. to obtain 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride, wherein the molar ratio of 2,6-dichloro-4-trifluoromethylaniline to nitrosyl chloride is 1:(1-1.05); the diazotization reaction product enters step 3; Step 3, condensation: add ethyl 2,3-dicyanopropionate and acetic acid to the diazotization reaction product, and carry out condensation reaction at a temperature of 20-35° C. to obtain ethyl 2,3-dicyano-2-(2,6-dichloro-trifluoromethylphenylazo)propionate; the molar ratio of 2,6-dichloro-4-trifluoromethylbenzene diazonium chloride to ethyl 2,3-dicyanopropionate is 1:(1-1.1); the condensation reaction product enters step 4; Step 4, hydrolysis: adding water to the condensation reaction product to perform hydrolysis, allowing the hydrolyzed product to stand and separate into layers, the aqueous phase of the hydrolyzed product entering step 6, and the organic phase of the hydrolyzed product entering step 5; the mass ratio of the condensation reaction product to the added water is 1:0.5-0.7; Step 5, cyclization: adding ammonia water or ammonia gas to the organic phase of the hydrolyzate to cause a cyclization reaction at a temperature of 20-40° C. to obtain a cyclization reaction product, and the cyclization reaction product enters step 7; Step 6, adsorption: adding a weakly basic ion exchange resin to the aqueous phase of the hydrolyzate to adsorb acetic acid in the aqueous phase of the hydrolyzate, and recycling the aqueous phase of the hydrolyzate after adsorption to step 1; Step 7, purification: adding toluene to the cyclization reaction product, cooling and crystallizing, the cooling rate is 1-4°C / h, the cooling end temperature is 0-10°C, and the crystalline solid is dried to obtain a refined product of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole.

2. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: In step 1, the concentration of the hydrochloric acid solution is 15-16 wt %, and the concentration of the hydrogen peroxide is 27.0-28.0 wt %.

3. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: In step 4, the hydrolysis reaction time is 1 to 2 hours, and the reaction temperature is room temperature.

4. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: In step 5, the concentration of aqueous ammonia is 20-25 wt%.

5. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: In step 6, the temperature of the saturated weak alkaline ion exchange resin is raised to 120-130° C., and the acetic acid adsorbed on the weak alkaline ion exchange resin is desorbed. The desorbed acetic acid is recovered by condensation and returned to step 2 and / or step 3.

6. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: The ion exchange resin in step 6 is a weak base ion exchange resin.

7. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: The ion exchange resin in step 6 is A-654 macroporous weak base anion exchange resin or HPA-330 epoxy weak base anion exchange resin.

8. The method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole according to claim 1, characterized in that: The acetic acid added in step 2 and step 3 is mainly used as a solvent and does not participate in the reaction.