Preparation method of 2-nitro-4-(trifluoromethyl)benzonitrile

Abstract

This invention discloses a method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile. Specifically, this invention discloses a method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile, which includes the following steps: (1) activating 4-chloro-3-nitrotrifluorotoluene with KF in the absence of solvent or in an aprotic solvent to obtain mixture I; (2) reacting mixture I with a cyaniding reagent to prepare 2-nitro-4-(trifluoromethyl)benzonitrile; wherein mixture I contains a portion of unactivated 4-chloro-3-nitrotrifluorotoluene. The method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile according to this invention is simple to operate and has a high yield.

Description

Technical Field

[0001] This invention belongs to the field of organic chemistry and relates to a method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile. Background Technology

[0002] 2-Nitro-4-(trifluoromethyl)benzonitrile is an important intermediate used in the synthesis of insecticides such as 4-benzoylisoxazole and isoxazolone, and herbicide 5-cyclopropylisoxazole. It is widely used in the fields of medicine, pesticides and chemicals.

[0003] 2-Nitro-4-(trifluoromethyl)benzonitrile has the molecular formula C8H3F3N2O2, a relative molecular mass of 216.1, a melting point of 44–47℃, a boiling point of 156–158℃, a density of 1.56 g / mL, and is a yellow crystalline solid at room temperature.

[0004] Synthetic methods for 2-nitro-4-(trifluoromethyl)benzonitrile and its similar compounds have been mentioned in literature and patents. For example, patent number CN1359372A mentions several different methods for preparing 2-nitro-4-(trifluoromethyl)benzonitrile from 4-chloro-3-nitrotrifluorotoluene, as follows:

[0005] Method 1: React 4-chloro-3-nitrotrifluorotoluene with cuprous cyanide and a bromide source.

[0006] Method 2: Reacting 4-chloro-3-nitrotrifluorotoluene with an alkali metal cyanide in the presence of cuprous bromide and a phase transfer catalyst;

[0007] Method 3: Reaction of 4-chloro-3-nitrotrifluorotoluene with cuprous cyanide and lithium metal salt;

[0008] Method 4: React 4-chloro-3-nitrotrifluorotoluene with an alkali metal cyanide.

[0009] Methods 1-3 are costly, cumbersome to operate, involve a wide variety of raw materials, and are difficult to recycle and reuse after processing, while method 4 has a low yield. Summary of the Invention

[0010] The technical problem to be solved by this invention is to overcome the shortcomings of existing methods for preparing 2-nitro-4-(trifluoromethyl)benzonitrile, which are characterized by complex operation or low yield, and to provide a new method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile. The method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile described in this invention is simple to operate and has a high yield.

[0011] The present invention solves the above-mentioned technical problems by means of the following method.

[0012] This invention provides a method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile, which includes the following steps:

[0013] (1) Activate 4-chloro-3-nitrotrifluorotoluene with KF in the absence of solvent or in an aprotic solvent to obtain mixture I;

[0014] (2) The mixture I is subjected to a cyanidation reaction with a cyanidating agent to prepare 2-nitro-4-(trifluoromethyl)benzonitrile.

[0015] The mixture I contains a portion of unactivated 4-chloro-3-nitrotrifluorotoluene.

[0016] The KF mentioned above can also be replaced with CsF, but in industrial production, CsF is more expensive. Therefore, from a cost perspective, using KF can better meet the needs of industrialization.

[0017] In one aspect of the present invention, the aprotic solvent is a polar aprotic solvent, such as one or more selected from nitrile solvents, amide solvents, sulfone solvents and sulfoxide solvents, preferably sulfone solvents and / or amide solvents.

[0018] Preferably, the nitrile solvent is selected from one or more of acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valerate, benzyl nitrile, and phenylacetonitrile, such as acetonitrile and / or benzyl nitrile.

[0019] Preferably, the amide solvent is selected from one or more of N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and N-ethylpyrrolidone, with N,N-dimethylformamide being the most preferred.

[0020] Preferably, the sulfone solvent is a cycloalkane sulfone solvent, such as one or more selected from dimethyl sulfone, 2,4-dimethylcyclobutane sulfone, and cyclobutane sulfone, with cyclobutane sulfone being preferred.

[0021] Preferably, the sulfoxide solvent is N,N-dimethyl sulfoxide and / or N,N-diethyl sulfoxide, for example, N,N-dimethyl sulfoxide.

[0022] In one embodiment of the present invention, the volume-to-mass ratio of the aprotic solvent to the 4-chloro-3-nitrotrifluorotoluene is 2 to 8 mL / g, for example, 3.1 mL / g, 3.2 mL / g, 3.3 mL / g, 3.4 mL / g, or 4.3 mL / g.

[0023] In one embodiment of the present invention, the equivalent ratio of KF to 4-chloro-3-nitrotrifluorotoluene is (0.01-2):1, for example, 0.05:1, 0.1:1, 0.3:1, 0.5:1, 1:1 or 1.2:1.

[0024] In one aspect of the present invention, the activation temperature is 60 to 200°C, for example 80°C, 100°C, 120°C, 140°C, 150°C or 160°C.

[0025] In one aspect of the present invention, the activation temperature and activation time satisfy the following conditions: after activation at the specified activation temperature and activation time, a portion of 4-chloro-3-nitrotrifluorotoluene still exists in the reaction system.

[0026] In one embodiment of the present invention, the activation temperature is 80-100°C and the activation time is 1-2 hours.

[0027] In one embodiment of the present invention, the activation temperature is 80°C and the activation time is 2 hours.

[0028] In one embodiment of the present invention, the activation temperature is 100°C and the activation time is 1 hour.

[0029] In one embodiment of the present invention, the activation temperature is 120–160°C and the activation time is 0.5–1 h.

[0030] In one embodiment of the present invention, the activation temperature is 120°C and the activation time is 0.5 h.

[0031] In one embodiment of the present invention, the activation temperature is 140°C and the activation time is 0.5 h.

[0032] In one embodiment of the present invention, the activation temperature is 150°C and the activation time is 0.5 h.

[0033] In one embodiment of the present invention, the activation temperature is 160°C and the activation time is 0.5 h.

[0034] The cyaniding reagent described is a cyaniding reagent conventionally used in this type of reaction in the art.

[0035] In one embodiment of the present invention, the cyaniding agent is selected from one or more of alkali metal cyanides, transition metal cyanides, alkali metal ferrocyanides, and alkali metal ferrocyanides, preferably alkali metal cyanides.

[0036] Preferably, the alkali metal cyanide is sodium cyanide and / or potassium cyanide, for example, potassium cyanide.

[0037] Preferably, the transition metal cyanide is zinc cyanide and / or cyanide ketone.

[0038] Preferably, the alkali metal ferrocyanide is potassium ferrocyanide.

[0039] Preferably, the alkali metal ferricyanide is potassium ferricyanide.

[0040] In one embodiment of the present invention, the equivalence ratio of the cyaniding agent to the 4-chloro-3-nitrotrifluorotoluene is (1 to 1.2):1, for example 1:1, 1.02:1 or 1.1:1.

[0041] In one embodiment of the present invention, the reaction temperature of the cyanidation reaction is 60-200°C, preferably 80-160°C, for example 80°C, 100°C, 120°C, 140°C, 150°C or 160°C.

[0042] The reaction time for the cyanidation reaction can be the time required for the raw material 4-chloro-3-nitrotrifluorotoluene to react completely.

[0043] In one embodiment of the present invention, the reaction time of the cyanidation reaction is 6 to 12 hours, for example, 6 hours, 8 hours or 12 hours.

[0044] In one aspect of the present invention, the activation temperature and activation time are...

[0045] The present invention also provides a method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile, which includes the following steps: in the absence of solvent or in an aprotic solvent, in the presence of KF, a mixture of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene is subjected to a cyanidation reaction with a cyanidating agent to prepare 2-nitro-4-(trifluoromethyl)benzonitrile.

[0046] In one aspect of the present invention, the mixture of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene contains 70% to 98% by mass, for example, 73.0%, 73.3%, 74.0%, 74.3%, 75.3%, 76.3%, 79.20%, 80.0%, 85.0%, 88.0%, 88.3%, 89.0%, 89.2%, 90.0%, 93.0%, 95.0%, and 96.0%.

[0047] In one aspect of the present invention, the type of aprotic solvent is as described above for the types of aprotic solvents in the present invention.

[0048] The volume-to-mass ratio of the aprotic solvent to the mixture of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene is 2 to 8 mL / g.

[0049] In one aspect of the present invention, the total amount of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene in the mixture of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene is 1 equivalent, and the equivalent of KF is 0.01 to 2, for example 0.05, 0.1, 0.3, 0.5, 1 or 1.2.

[0050] In one aspect of the present invention, the type of cyaniding reagent is as described in the above-described types of cyaniding reagents of the invention.

[0051] In one aspect of the present invention, the total amount of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene in the mixture of 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene is 1 equivalent, and the equivalent of the cyaniding agent is 1 to 1.2, for example 1, 1.02 or 1.1.

[0052] In one aspect of the present invention, the reaction temperature of the cyanidation reaction is as described above.

[0053] The reaction time for the cyanidation reaction can be the time required for the 4-chloro-3-nitrotrifluorotoluene and 4-fluoro-3-nitrotrifluorotoluene to react completely.

[0054] In one aspect of the present invention, the reaction time of the cyanidation reaction is as described above regarding the cyanidation reaction time of the present invention.

[0055] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0056] The reagents and raw materials used in this invention are all commercially available.

[0057] The positive and progressive effects of this invention are that the preparation method of 2-nitro-4-(trifluoromethyl)benzonitrile of this invention is simple to operate and has a high yield. Detailed Implementation

[0058] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0059] In the following examples, the purity test was performed using a GC instrument. The analytical method parameters are as follows:

[0060]

[0061]

[0062] Example 1: Single-factor experiment on KF dosage

[0063] Add 22.5 g (0.1 mol, 1 eq) of 4-chloro-3-nitrotrifluorotoluene to a reaction flask, add 92 g of sulfolane solvent, stir, add KF, heat to 160 °C, stir for 0.5 h, keep warm, add 6.6 g (1.02 eq) of potassium cyanide, after the potassium cyanide is added, continue the reaction, keep warm until the 4-chloro-3-nitrotrifluorotoluene reacts completely, cool to room temperature, and post-process to obtain 2-nitro-4-(trifluoromethyl)benzonitrile.

[0064] The specific experimental results are as follows: (The feed equivalent of KF in the following table is based on 4-chloro-3-nitrotrifluorotoluene)

[0065]

[0066] Example 2: Single-factor experiment on activation temperature

[0067] Add 22.5 g (0.1 mol, 1 eq) of 4-chloro-3-nitrotrifluorotoluene to a reaction flask, add 90 g of sulfolane solvent, stir, add 5.8 g (1.0 eq) of KF, heat to the activation temperature, stir for 0.5 h, keep warm, add 6.6 g (1.02 eq) of potassium cyanide, after the potassium cyanide is added, continue the reaction, keep warm until the 4-chloro-3-nitrotrifluorotoluene reacts completely, cool to room temperature, and post-process to obtain 2-nitro-4-(trifluoromethyl)benzonitrile.

[0068] The specific experimental results are as follows:

[0069]

[0070] Example 3

[0071] Add 22.5 g (0.1 mol, 1 eq) of 4-chloro-3-nitrotrifluorotoluene to a reaction flask, add 92 g of sulfolane solvent, stir, add KF (5.8 g, 1.0 eq), heat to the activation temperature (experimental variable), stir for 0.5-2 h (experimental variable), keep warm, add potassium cyanide (6.6 g, 1.02 eq), after the potassium cyanide is added, continue the reaction, keep warm until the 4-chloro-3-nitrotrifluorotoluene reacts completely, cool to room temperature, and post-process to obtain 2-nitro-4-(trifluoromethyl)benzonitrile.

[0072]

[0073] Example 4: Single-factor experiment on cyanide reagent

[0074] 22.5 g (0.1 mol, 1 eq) of 4-chloro-3-nitrotrifluorotoluene was added to a reaction flask, along with 92 g of DMF solvent. The mixture was stirred, and 5.8 g (1.0 eq) of KF was added. The temperature was raised to 160 °C, and the mixture was stirred for 0.5 h. The purity of 4-chloro-3-nitrotrifluorotoluene (t = 5.6 min) and 4-fluoro-3-nitrotrifluorotoluene (t = 4.6 min) in the reaction solution was 73.3% and 25.6%, respectively. The mixture was kept at this temperature, and cyaniding reagent (1.02 eq) was added. After the addition was complete, the reaction continued, and the temperature was maintained until the reaction of 4-chloro-3-nitrotrifluorotoluene was complete. The mixture was then cooled to room temperature, and post-treatment yielded 2-nitro-4-(trifluoromethyl)benzonitrile.

[0075] When the reaction solvent is replaced by sulfolane instead of DMF, the reaction effect is similar to that when DMF is used as the solvent.

[0076]

[0077] Example 5

[0078] Add 22.5 g (0.1 mol, 1 eq) of 4-chloro-3-nitrotrifluorotoluene to a reaction flask, add solvent (3 mL solvent per gram of raw material), stir, add KF (1.0 eq), heat to 160 °C, stir for 0.5 h, keep warm, add potassium cyanide (1.02 eq), after the addition is complete, continue the reaction according to the reaction time and reaction temperature in the table below until the 4-chloro-3-nitrotrifluorotoluene has reacted completely, cool to room temperature, and post-process to obtain 2-nitro-4-(trifluoromethyl)benzonitrile.

[0079]

[0080] 'a' indicates that when acetonitrile is used as a solvent, the activation temperature is the temperature at which it is refluxed.

[0081] Example 6

[0082]

[0083] 22.6 g of 4-chloro-3-nitrotrifluorotoluene (1 eq.) was added to a reaction flask, followed by 70 mL of DMF and stirring. 2.9 g of KF (0.5 eq.) was added, and the mixture was heated to 100 °C and stirred for 1 h. The purity of chloro-3-nitrotrifluorotoluene (t = 5.6 min) and 4-fluoro-3-nitrotrifluorotoluene (t = 4.6 min) was 88.3% and 11.6% respectively. The mixture was kept at this temperature, and potassium cyanide (1.02 eq.) was added. The temperature was further increased to 150 °C and maintained until the reaction of the 4-chloro-3-nitrotrifluorotoluene was complete. The mixture was then cooled to room temperature, and post-treatment yielded 19.45 g of 2-nitro-4-(trifluoromethyl)benzonitrile with a purity of 99% and a yield of 90%.

[0084] Example 7

[0085]

[0086] 22.6 g of 4-chloro-3-nitrotrifluorotoluene (1 eq.) was added to a reaction flask, followed by 70 mL of DMF and stirring. 5.8 g of KF (1 eq.) was added, and the mixture was heated to 140 °C and stirred for 0.5 h. The purity of 4-chloro-3-nitrotrifluorotoluene (t = 5.6 min) and 4-fluoro-3-nitrotrifluorotoluene (t = 4.6 min) was 79.2% and 20.6% respectively. The mixture was kept at this temperature, and 1.02 eq. of potassium cyanide was added. After the potassium cyanide was completely added, the reaction continued, and the temperature was maintained until the 4-chloro-3-nitrotrifluorotoluene had completely reacted. The mixture was then cooled to room temperature, and post-processing yielded 19.2 g of 2-nitro-4-(trifluoromethyl)benzonitrile with a purity of 99% and a yield of 89%.

[0087] Example 8

[0088]

[0089] 22.6 g of 4-chloro-3-nitrotrifluorotoluene (1 eq.) was added to a reaction flask, followed by 70 mL of DMF and stirring. 5.8 g of KF (1 eq.) was added, and the mixture was heated to 140 °C and stirred for 0.5 h. The purity of 4-chloro-3-nitrotrifluorotoluene (t = 5.6 min) and 4-fluoro-3-nitrotrifluorotoluene (t = 4.6 min) was 76.3% and 20.6% respectively. The mixture was kept at this temperature, and 5.9 g of sodium cyanide (1.02 eq.) was added. After the sodium cyanide was added, the reaction continued, and the temperature was maintained until the 4-chloro-3-nitrotrifluorotoluene had completely reacted. The mixture was then cooled to room temperature, and post-processing yielded 19.45 g of 2-nitro-4-(trifluoromethyl)benzonitrile with a purity of 99% and a yield of 90%.

[0090] Example 9

[0091]

[0092] 22.6 g of 4-chloro-3-nitrotrifluorotoluene (1 eq.) was added to a reaction flask and stirred. 5.8 g of KF (1 eq.) was added, and the temperature was raised to 150 °C. The mixture was stirred for 0.5 h. The purity of 4-chloro-3-nitrotrifluorotoluene (t = 5.6 min) in the reaction solution was 73.3%, and the purity of 4-fluoro-3-nitrotrifluorotoluene (t = 4.6 min) was 24.7%. The mixture was kept at this temperature, and 6.6 g of potassium cyanide (1.02 eq.) was added. After the potassium cyanide was added, the reaction continued and the temperature was maintained until the 4-chloro-3-nitrotrifluorotoluene reacted completely. The mixture was then cooled to room temperature, and post-processing yielded 15.13 g of 2-nitro-4-(trifluoromethyl)benzonitrile with a purity of 99% and a yield of 70%.

[0093] Example 10

[0094]

[0095] 45.2 g of 4-chloro-3-nitrotrifluorotoluene (1 eq.) was added to a reaction flask, followed by 150 mL of sulfolane. The mixture was stirred, and 11.6 g of KF (1 eq.) was added. The temperature was raised to 80 °C, and the mixture was stirred for 2 h. The purity of 4-chloro-3-nitrotrifluorotoluene (t = 5.6 min) in the reaction solution was 89.2%, and the purity of 4-fluoro-3-nitrotrifluorotoluene (t = 4.6 min) was 9.9%. The mixture was kept at this temperature, and 13.2 g of potassium cyanide (1.02 eq.) was added. After the potassium cyanide was added, the temperature was raised to 160 °C, and the reaction was continued. The temperature was maintained until the reaction of 4-chloro-3-nitrotrifluorotoluene was completed. The mixture was then cooled to room temperature, and 37.2 g of 2-nitro-4-(trifluoromethyl)benzonitrile was obtained with a purity of 99% and a yield of 86%.

[0096] Example 11

[0097] Add 45.1 g of 4-chloro-3-nitrotrifluorotoluene to a reaction flask, add 181 g of solvent, stir, add 11.6 g of KF, heat to 160 °C, stir for 1 h. If there is any raw material remaining, keep warm, add 13.3 g of potassium cyanide (1.02 eq). After the potassium cyanide is added, continue the reaction and keep warm until the 4-chloro-3-nitrotrifluorotoluene has reacted completely. Cool to room temperature and post-process to obtain 2-nitro-4-(trifluoromethyl)benzonitrile.

[0098] The specific experimental results are as follows:

[0099] Serial Number Temperature / °C KF equivalent / eq. solvent Yield / % 31 160 1 Sulfolane 86 32 160 1 benzyl nitrile 71

[0100] Example 12

[0101] 22.3 g of 4-chloro-3-nitrotrifluorotoluene (1 eq.) was added to the flask, followed by 72 mL of DMF and stirring. 5.9 g of KF (1.0 eq.) was added, and the mixture was heated to 140 °C and stirred for 0.5 h. The reaction solution was then subjected to intermediate control (normalized content in the chromatogram, t is the retention time): 4-chloro-3-nitrotrifluorotoluene had a purity of 75.3% at t = 5.6 min, and 4-fluoro-3-nitrotrifluorotoluene had a purity of 23.6% at t = 4.6 min.

[0102] Add KCN (1.02 eq.), and after the potassium cyanide is added, continue the reaction. Keep warm until the raw material 4-chloro-3-nitrotrifluorotoluene has basically reacted. Cool down to room temperature, and after post-treatment, 19.3 g of 2-nitro-4-(trifluoromethyl)benzonitrile is obtained with a purity of 99% and a yield of 90%.

Claims

1.A method for preparing 2-nitro-4-(trifluoromethyl)benzonitrile, comprising the following steps: (1) activating 4-chloro-3-nitro-trifluorotoluene with KF in an aprotic solvent to obtain a mixture I; the aprotic solvent is an amide solvent and / or a sulfone solvent; the amide solvent is N, N-dimethylformamide, and the sulfone solvent is selected from one or more of dimethyl sulfone, 2, 4-dimethylcyclobutane sulfone and cyclobutane sulfone; the equivalent ratio of KF to 4-chloro-3-nitro-trifluorotoluene is (0.1-2) : 1; the temperature and time of the activation are any of the following cases: case one: the temperature of the activation is 80-100℃, and the time of the activation is 1-2h; case two: the temperature of the activation is 120-160℃, and the time of the activation is 0.5-1h; (2) performing a cyanation reaction on the mixture I with a cyanating agent to prepare 2-nitro-4-(trifluoromethyl)benzonitrile; the cyanating agent is an alkali metal cyanide, and the alkali metal cyanide is sodium cyanide and / or potassium cyanide; the mixture I contains part of unactivated 4-chloro-3-nitro-trifluorotoluene. One or more of the following conditions are met: (1) the volume-mass ratio of the aprotic solvent to 4-chloro-3-nitro-trifluorotoluene is 2-8mL / g; (2) the equivalent ratio of KF to 4-chloro-3-nitro-trifluorotoluene is 0.1:1, 0.3:1, 0.5:1, 1:1 or 1.2:1; (3) the temperature of the activation is 80℃, 100℃, 120℃, 140℃, 150℃ or 160℃; (4) the alkali metal cyanide is potassium cyanide; (5) the equivalent ratio of the cyanating agent to 4-chloro-3-nitro-trifluorotoluene is (1-1.2) : 1; (6) the reaction temperature of the cyanation reaction is 60-200℃. The sulfone solvent is cyclobutane sulfone. One or more of the following conditions are met: (1) the volume-mass ratio of the aprotic solvent to 4-chloro-3-nitro-trifluorotoluene is 3.1mL / g, 3.2mL / g, 3.3mL / g, 3.4mL / g or 4.3mL / g; (2) the equivalent ratio of the cyanating agent to 4-chloro-3-nitro-trifluorotoluene is 1:1, 1.02:1 or 1.1:1; (3) the reaction temperature of the cyanation reaction is 80-160℃. The reaction temperature of the cyanation reaction is 80℃, 100℃, 120℃, 140℃, 150℃ or 160℃. The temperature and time of the activation are any of the following cases: (1) the temperature of the activation is 80℃, and the time of the activation is 2h; (2) the temperature of the activation is 100℃, and the time of the activation is 1h; (3) the temperature of the activation is 120℃, and the time of the activation is 0.5h; (4) the temperature of the activation is 140℃, and the time of the activation is 0.5h. ​ ​ ​ ​ 2. The process for the preparation of 2-nitro-4-(trifluoromethyl)benzonitrile according to claim 1, characterized in that, ​ ​ ​ ​ ​ ​ ​ 3. The process for the preparation of 2-nitro-4-(trifluoromethyl)benzonitrile according to claim 1, characterized in that, ​ 4. The process for preparing 2-nitro-4-(trifluoromethyl)benzonitrile according to claim 2, wherein the reaction is carried out in the presence of a base. ​ ​ ​ ​ 5. The process for the preparation of 2-nitro-4-(trifluoromethyl)benzonitrile according to claim 4, characterized in that, ​ 6. The process for the preparation of 2-nitro-4-(trifluoromethyl)benzonitrile according to claim 1, characterized in that, ​ ​ ​ ​ ​ (5) the temperature of the activation is 150℃, and the time of the activation is 0.5h; (6) the temperature of the activation is 160℃, and the time of the activation is 0.5h.

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