Method for electrochemical synthesis of aromatic nitrile from methyl aromatic hydrocarbon

Abstract

The invention relates to a method for electrochemical synthesis of aromatic nitrile from methyl aromatic hydrocarbon, and belongs to the technical field of organic synthesis. According to the method, rich methyl aromatic hydrocarbon is taken as a starting raw material, hydroxylamine which is safe, non-toxic, low in price and easy to obtain is taken as a nitrogen source, and the methyl aromatic hydrocarbon is directly converted into aromatic nitrile through electrochemical reaction with electrolyte, deionized water, an acidic material and an organic solvent in a diaphragm-free electrolytic tank. The method does not need to introduce a transition metal catalyst and an external oxidant, does not need a sacrificial anode, is simple and mild in reaction condition, is a green, simple and efficient nitrile preparation method, and has a huge application prospect in synthesis of aromatic nitrile.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis and relates to a method for electrochemically synthesizing aromatic nitriles from methyl aromatics. Background Art

[0002] Nitrile compounds containing a cyano group have important applications in fields such as dyes, agrochemicals, and electronic materials. In the pharmaceutical field, the cyano group exists as a key pharmacophore in many drug molecules, such as the anti-tumor drug Letrozole, the bronchodilator Cromakalim, and the cardiotonic drug Milrinone. In addition, nitrile compounds are important intermediates in organic synthesis and can be converted into derivatives such as aldehydes, ketones, carboxylic acids, esters, amides, and amines through various pathways such as hydrolysis, reduction, and Grignard reactions.

[0003] The direct nucleophilic substitution reaction (SN2 reaction) of aliphatic halogenated hydrocarbons using NaCN or KCN as a cyanide source is one of the classic methods for preparing aliphatic nitriles. In contrast, the synthesis of aromatic nitriles is usually more challenging, mainly due to the lower nucleophilic substitution reactivity of the aromatic ring SP 2 carbon atoms and the need for higher energy to break the aromaticity of the aromatic ring. In 1884, Sandmeyer first reported a method for preparing aromatic nitriles by reacting aromatic diazonium salts with cuprous cyanide (I) (Sandmeyer reaction), which is still one of the important strategies for aromatic nitrile synthesis to this day. This method utilizes the high reactivity of aromatic diazonium salts to achieve cyanation of the aromatic ring under mild conditions. However, this method has the following limitations: (1) It requires the use of highly toxic cuprous cyanide as a cyanide source; (2) It is limited to aromatic diazonium salt substrates; (3) Due to the thermal instability of the diazo intermediate, the reaction usually needs to be carried out at a low temperature of 0-5 °C [Sandmeyer, T. Ueber die Ersetzung der Amidgruppe durch Chlor inden aromatischen Substanzen. Ber. Dtsch. Chem. Ges. 1884, 17(2), 1633-1635]. (The chemical reaction equation is: ). Although the aldehyde oxime dehydration method and the amide dehydration method avoid the direct use of cyanides, these methods usually have the following disadvantages: (1) They require strong dehydrating agents (such as P2O5 or SOCl2); (2) The reaction conditions are relatively severe (high temperature, strong acidic environment); (3) They have poor compatibility with substrates containing sensitive functional groups such as hydroxyl and amino groups. Therefore, the development of new methods for synthesizing aromatic nitriles with milder conditions, better functional group compatibility, and environmental friendliness remains an important research topic in modern organic synthetic chemistry.

[0004] In recent years, novel synthetic methods such as transition-metal-catalyzed and photocatalyzed C-H bond activation cyanation have become research hotspots. Meanwhile, important progress has also been made in developing new synthetic routes for aromatic nitriles based on cheap and readily available methylarenes. In 2013, the Wang research group reported a mild Pd(II)-catalyzed ammoxidation reaction of methylarenes [Shu, Z.; Ye, Y.; Deng, Y.; Zhang, Y.; Wang, J. Palladium(II)-Catalyzed Direct Conversion of Methyl Arenes into Aromatic Nitriles. Angew. Chem., Int. Ed. 2013, 52(40), 10573-10576]. This reaction uses a Pd(OAc)2 and N-hydroxyphthalimide (NHPI) catalytic system, with tert-butyl nitrite serving as both the nitrogen source and the oxidant, achieving the direct conversion of methylarenes to aromatic nitriles. This method avoids the use of highly toxic cyanides in traditional cyanation reactions (chemical reaction equation: ). In 2020, The research group reported a visible-light-catalyzed direct cyanation method for toluene derivatives [Murugesan, K.; Donabauer, K.; Konig, B. Visible-Light-Promoted Metal-Free Synthesis of (Hetero)Aromatic Nitriles from C(sp 3 )-H Bonds. Angew. Chem., Int. Ed. 2021, 60(5), 2439-2445]. This reaction uses an organic photocatalyst to achieve the synthesis of aromatic nitriles in one step through C(sp 3 )-H bond activation under metal-free and cyanide-free conditions (chemical reaction equation: ). The application of electrochemistry in organic chemistry provides a new approach for synthetic transformations beyond traditional methods. It uses "more environmentally friendly" electricity to replace traditional chemical oxidants to promote the occurrence of reactions, which not only conforms to the principles of green chemistry but also enables excellent reaction selectivity through precise regulation of the electrode potential, providing a new and powerful strategy for C-H functionalization. For example, in 2016, the Li research group reported an electrochemical method for the synthesis of nitriles from aldehydes using a catalytic amount of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) as the medium and hexamethyldisilazane (HMDS) as the nitrogen source (chemical reaction equation: )[Chen, Q.; Fang, C.; Shen, Z.; Li, M. Electrochemical Synthesis of Nitriles from Aldehydes using TEMPO as a Mediator. Electrochem. Commun. 2016, 64, 51 - 55]. However, there is no reported electrochemical strategy for directly converting inexpensive and readily available aromatic hydrocarbons into aromatic nitriles. Therefore, it is necessary to develop a method for the electrochemical synthesis of aromatic nitriles from methylaromatic hydrocarbons, so as to provide a new idea for the green, simple and efficient preparation of nitrile compounds. Summary of the Invention

[0005] In view of this, one of the purposes of the present invention is to provide a method for the electrochemical synthesis of aromatic nitriles from methylaromatic hydrocarbons.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] 1. A method for the electrochemical synthesis of aromatic nitriles from methylaromatic hydrocarbons, the method is: placing methylaromatic hydrocarbons, hydroxylamine sulfate, electrolyte, deionized water, acidic substance and organic solvent in a diaphragm-free electrolytic cell, inserting an anode and a cathode, and then stirring for 5 - 22 h under the conditions of room temperature, air atmosphere and constant current to carry out an electrochemical reaction. After the reaction is completed, a reaction mixture is obtained. The reaction mixture is successively subjected to extraction, washing, drying, solvent removal and purification to obtain aromatic nitriles;

[0008] The methylaromatic hydrocarbon is any one of 2-methylnaphthalene, 4-methylbiphenyl, 2-methylbiphenyl, 4-methyl-4'-methylbiphenyl, 4-methyl-3',5'-dimethylbiphenyl, 4-methyl-4'-ethylbiphenyl, 4-methyl-4'-fluorobiphenyl, 4-methyl-4'-chlorobiphenyl, 4-methyl-4'-bromobiphenyl, 4-methyl-4'-ethoxybiphenyl, 4-methyl-4'-propoxybiphenyl, 4-methoxytoluene, 2-methoxytoluene, 4-ethoxytoluene, 4-isopropoxytoluene, 4-tert-butoxytoluene, 4-isobutoxytoluene, 3,4-dimethoxytoluene, 3,4-(methylenedioxy)toluene, 3,4,5-trimethoxytoluene, 3-methyl-4-methoxytoluene, 2-methyl-4-methoxytoluene, 3,5-dimethyl-4-methoxytoluene, 3-fluoro-4-methoxytoluene, 3-chloro-4-methoxytoluene, 2-bromo-4-methoxytoluene, 3-bromo-4-methoxytoluene, or 4-phenoxytoluene.

[0009] Preferably, the electrolyte is any one of tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, tetraethylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, sodium tetrafluoroborate, sodium perchlorate, lithium perchlorate, tetraethylammonium perchlorate, tetrabutylammonium perchlorate, potassium hexafluorophosphate, tetrabutylammonium trifluoromethanesulfonate or tetraethylammonium methanesulfonate.

[0010] Preferably, the acidic substance is any one of trifluoroacetic acid, acetic acid, boric acid or boron trifluoride etherate.

[0011] Preferably, the organic solvent is any one of dimethyl sulfoxide, dichloromethane, dichloroethane, a mixed solution formed by dimethyl sulfoxide and dichloroethane or hexafluoroisopropanol.

[0012] Preferably, the material of the anode is any one of platinum or carbon; the material of the cathode is any one of nickel foam, copper foam, carbon or platinum.

[0013] Preferably, the constant current is 10 - 120 mA.

[0014] Preferably, the molar ratio of the methylarene to the hydroxylamine sulfate is 1:1.5 - 1:4; the molar ratio of the methylarene to the electrolyte is 1:1 - 1:1.5; the molar volume ratio of the methylarene to the deionized water is 1:167 - 1:300, mmol:mL; the molar ratio of the methylarene to the acidic substance is 1:1.5 - 1:4; the molar volume ratio of the methylarene to the organic solvent is 1:4 - 1:16.7, mmol:mL.

[0015] Preferably, the stirring speed is 600 - 700 rpm / min.

[0016] The beneficial effects of the present invention are as follows: The present invention provides a method for electrochemically synthesizing aromatic nitriles from methylarenes. This method uses abundant methylarenes as starting materials and safe, non-toxic and inexpensive hydroxylamine as a nitrogen source, and realizes the conversion from methylarenes to aromatic nitriles through an electrochemical reaction in a diaphragmless electrolytic cell. This method does not require a transition metal catalyst and an external oxidant, does not require a sacrificial anode, and the reaction conditions are simple and mild, which is a more green, simple and efficient method for preparing nitriles.

[0017] Other advantages, objectives and features of the present invention will be elaborated to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail with reference to the accompanying drawings, where:

[0019] Figure 1 This is a possible reaction mechanism diagram for the electrochemical oxidation of methylarene to form aromatic nitrile in the present invention. Specific embodiments

[0020] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following examples only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following examples and the features in the examples can be combined with each other.

[0021] The following examples all react according to the following reaction equation:

[0022]

[0023] The abbreviations used in the following examples are specifically:

[0024] n Bu4NBF4 represents tetrabutylammonium tetrafluoroborate; DMSO represents dimethyl sulfoxide; DCE represents dichloroethane; TFA represents trifluoroacetic acid.

[0025] Example 1

[0026] Prepare 4-cyanobiphenyl, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical bottle as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 4-methylbiphenyl, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol of nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, an air atmosphere, and a constant current of 20 mA, stirring was carried out at a speed of 600 rpm / min for 20 h to conduct an electrochemical reaction. After the reaction ended, a reaction mixture was obtained. The reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-1 (38.7 mg, yellow oil, yield 72%).

[0027] 1 1H NMR (600 MHz, Chloroform-d) δ 7.71 (d, J = 8.1 Hz, 2H), 7.67 (d, J = 8.0 Hz, 2H), 7.58 (dd, J = 7.3, 1.7 Hz, 2H), 7.48 (t, J = 7.7 Hz, 2H), 7.45–7.39 (m, 1H); 13 13C NMR (151 MHz, Chloroform-d) δ 145.7, 139.2, 132.6, 129.1, 128.7, 127.7, 127.2, 118.9, 111.1.

[0028] Example 2

[0029] To prepare 2-cyanobiphenyl, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 2-methylbiphenyl, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol of nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added. Two platinum plates each with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, air atmosphere, and a constant current of 20 mA, stirring was carried out at a speed of 600 rpm / min for 20 h to conduct an electrochemical reaction. After the reaction ended, a reaction mixture was obtained. The reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-2 (26.9 mg, yellow oil, yield 50%).

[0030] 1 1H NMR (600 MHz, Chloroform-d) δ 7.76 (dd, J = 7.8, 1.4 Hz, 1H), 7.64 (td, J = 7.7, 1.4 Hz, 1H), 7.59–7.54 (m, 2H), 7.53–7.47 (m, 3H), 7.47–7.40 (m, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 145.5, 138.2, 133.8, 132.8, 130.1, 128.8, 128.7, 128.7, 127.6, 118.7, 111.3.

[0031] Example 3

[0032] To prepare 4-cyano-4'-methylbiphenyl, whose structural formula is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 4-methyl-4'-methylbiphenyl, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol n0.3 mmol of 4-methyl-3',5'-dimethylbiphenyl, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added to a 10 mL cylindrical flask, which was used as a diaphragm-free electrolytic cell. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution), and then the mixture was stirred at a speed of 600 rpm / min for 20 h under the conditions of room temperature, air atmosphere, and a constant current of 20 mA to carry out the electrochemical reaction. After the reaction was completed, the reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f The target product II-3 (41.1 mg, yellow oil, yield 71%) can be obtained.

[0033] 1 1H NMR (600 MHz, Chloroform-d) δ 7.69 (d, J = 8.4 Hz, 2H), 7.65 (d, J = 8.6 Hz, 2H), 7.50–7.46 (m, 2H), 7.28 (d, J = 7.9 Hz, 2H), 2.41 (s, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 145.6, 138.8, 136.3, 132.6, 129.9, 127.5, 127.1, 119.0, 110.6, 21.2.

[0034] Example 4

[0035] To prepare 4-cyano-3',5'-dimethylbiphenyl, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell, and then 0.3 mmol of 4-methyl-3',5'-dimethylbiphenyl, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of a DMSO / DCE (4:1 v / v) mixed organic solvent, and a magnetic stir bar were added. Two platinum plates each with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm into the reaction solution), and then the mixture was stirred at 600 rpm / min for 20 h under constant current of 20 mA at room temperature in an air atmosphere to carry out the electrochemical reaction. After the reaction, the reaction mixture was poured into 30 mL of H2O, extracted three times with 30 mL of ethyl acetate, the combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-4 (43.5 mg, yellow oil, yield 70%).

[0036] 1 1H NMR (600 MHz, Chloroform-d) δ 7.69–7.61 (m, 4H), 7.18 (s, 2H), 7.05 (s, 1H), 2.38 (s, 6H); 13 13C NMR (151 MHz, Chloroform-d) δ 146.0, 139.2, 138.7, 132.5, 130.3, 127.7, 125.12, 119.0, 110.7, 21.4.

[0037] Example 5

[0038] To prepare 4-cyano-4'-ethylbiphenyl, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell, and then 0.3 mmol of 4-methyl-4'-ethylbiphenyl, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, air atmosphere, and a constant current of 20 mA, stirring was carried out at a speed of 600 rpm / min for 22 h to conduct an electrochemical reaction. After the reaction ended, the reaction mixture was obtained. The reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-5 (25.0 mg, yellow oil, yield 40%).

[0039] 1 1H NMR (600 MHz, Chloroform-d) δ 7.68 (d, J = 8.1 Hz, 2H), 7.65 (d, J = 8.1 Hz, 2H), 7.50 (d, J = 7.8 Hz, 2H), 7.30 (d, J = 7.8 Hz, 2H), 2.70 (q, J = 7.6 Hz, 2H), 1.28 (t, J = 7.7 Hz, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 145.6, 145.1, 136.5, 132.6, 128.7, 127.5, 127.2, 119.0, 110.6, 28.6, 15.5.

[0040] Example 6

[0041] To prepare 4-cyano-4'-fluorobiphenyl, whose structural formula is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 4-methyl-4'-fluorobiphenyl, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol nMix 0.3 mmol of 4-methyl-4'-chlorobiphenyl, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar. Insert two platinum sheets with dimensions of 52 mm × 8 mm × 0.2 mm each as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution). Then, stir at a speed of 600 rpm for 20 h under the conditions of room temperature, air atmosphere, and a constant current of 20 mA to carry out the electrochemical reaction. After the reaction is completed, obtain the reaction mixture. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate. The combined organic layers are washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent is removed by distillation under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-6 (43.1 mg, yellow oil, yield 73%).

[0042] 1 1H NMR (600 MHz, Chloroform-d) δ 7.72 (d, J = 8.0 Hz, 2H), 7.64 (d, J = 8.0 Hz, 2H), 7.56 (dd, J = 8.6, 5.4 Hz, 2H), 7.17 (t, J = 8.4 Hz, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 163.2 (d, J = 249.1 Hz), 162.4, 144.6, 135.3 (d, J = 3.0 Hz), 129.0 (d, J = 7.6 Hz), 127.6, 118.8, 116.1 (d, J = 22.7 Hz), 111.0. 19 19F NMR (565 MHz, Chloroform-d) δ -113.2.

[0043] Example 7

[0044] Prepare 4-cyano-4'-chlorobiphenyl, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell. Then, add 0.3 mmol of 4-methyl-4'-chlorobiphenyl, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of nMix 0.9 mmol of TFA, 100 μL of H2O, 5 mL of DMSO / DCE (4:1 v / v) mixed organic solvent and a magnetic stir bar, and insert two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution). Then, stir at a speed of 600 rpm for 20 h under the conditions of room temperature, air atmosphere, and a constant current of 20 mA to carry out an electrochemical reaction. After the reaction is completed, obtain the reaction mixture. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then distill off the solvent under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-7 (44.1 mg, yellow oil, yield 69%).

[0045] 1 1H NMR (600 MHz, Chloroform-d) δ 7.73 (d, J = 8.0 Hz, 2H), 7.65 (d, J = 8.0 Hz, 2H), 7.52 (d, J = 8.1 Hz, 2H), 7.45 (d, J = 8.1 Hz, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 144.4, 137.6, 135.0, 132.7, 129.3, 128.5, 127.6, 118.7, 111.3。

[0046] Example 8

[0047] Prepare 4-cyano-4'-bromobiphenyl, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical bottle as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 4-methyl-4'-bromobiphenyl, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol nA mixture of Bu4NBF4 (100 μL), H2O (100 μL), TFA (0.9 mmol), a mixed organic solvent of 5 mL DMSO / DCE (4:1 v / v), and a magnetic stir bar was prepared. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, the mixture was stirred at 600 rpm / min for 20 h under constant current of 20 mA at room temperature in an air atmosphere to carry out the electrochemical reaction. After the reaction, the reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-8 (50.1 mg, yellow oil, yield 65%).

[0048] 1 1H NMR (600 MHz, Chloroform-d) δ 7.74–7.70 (m, 2H), 7.67–7.63 (m, 2H), 7.60 (d, J = 8.4 Hz, 2H), 7.45 (d, J = 8.5 Hz, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 144.4, 138.1, 132.7, 132.3, 128.8, 127.6, 123.2, 118.7, 111.4.

[0049] Example 9

[0050] To prepare 4-cyano-4'-ethoxybiphenyl, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 4-methyl-4'-ethoxybiphenyl, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol of nMix 100 μL of Bu4NBF4, 0.9 mmol of TFA, 5 mL of a DMSO / DCE (4:1 v / v) mixed organic solvent, and a magnetic stir bar, insert two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm each as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 16 h under the conditions of room temperature, air atmosphere, and a constant current of 20 mA to carry out an electrochemical reaction. After the reaction is completed, the reaction mixture is obtained. Pour this reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, distill off the solvent under reduced pressure, and finally purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-9 (41.5 mg, yellow oil, yield 62%).

[0051] 1 1H NMR (600 MHz, Chloroform-d) δ 7.75–7.61 (m, 4H), 7.52 (dd, J = 9.0, 2.5 Hz, 2H), 6.98 (dt, J = 9.1, 2.7 Hz, 2H), 4.08 (q, J = 7.1 Hz, 2H), 1.44 (t, J = 6.9 Hz, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 159.6, 145.3, 132.6, 131.3, 128.3, 127.1, 119.1, 115.1, 110.1, 63.7, 14.8.

[0052] Example 10

[0053] Prepare 4-cyano-4'-propoxybiphenyl, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical bottle as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 4-methyl-4'-propoxybiphenyl, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of DMSO / DCE (4:1 v / v) mixed organic solvent, and a magnetic stir bar were added. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution), and then the mixture was stirred at 600 rpm / min for 16 h under the conditions of room temperature, air atmosphere, and a constant current of 20 mA to carry out the electrochemical reaction. After the reaction was completed, the reaction mixture was poured into 30 mL of H2O, extracted three times with 30 mL of ethyl acetate, the combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-10 (44.8 mg, yellow oil, yield 63%).

[0054] 1 1H NMR (600 MHz, Chloroform-d) δ 7.67 (d, J = 8.0 Hz, 2H), 7.63 (d, J = 8.1 Hz, 2H), 7.58–7.48 (m, 2H), 7.05–6.93 (m, 2H), 3.97 (t, J = 6.5 Hz, 2H), 1.84 (h, J = 7.1 Hz, 2H), 1.06 (t, J = 7.4 Hz, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 159.9, 145.3, 132.6, 131.3, 128.3, 127.1, 119.1, 115.2, 110.1, 69.7, 22.6, 10.5.

[0055] Example 11

[0056] To prepare 4-methoxybenzonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell, and then 0.3 mmol of 4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol n0.3 mmol of 2 - methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added to a 10 mL cylindrical flask, which was used as a diaphragm - free electrolytic cell. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, air atmosphere, and a constant current of 10 mA, the mixture was stirred at a speed of 600 rpm for 12 h to carry out the electrochemical reaction. After the reaction was completed, the reaction mixture was poured into 30 mL of H2O, extracted three times with 30 mL of ethyl acetate, the combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f After the reaction, the reaction mixture was poured into 30 mL of H2O, extracted three times with 30 mL of ethyl acetate, the combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R

[0057] 1 H NMR (600 MHz, Chloroform - d) δ 7.58 (dd, J = 7.6, 4.8 Hz, 2H), 7.04–6.85 (m, 2H), 3.86 (d, J = 3.3 Hz, 3H); 13 C NMR (151 MHz, Chloroform - d) δ 162.9, 134.0, 119.2, 114.8, 104.0, 55.6.

[0058] Example 12

[0059] To prepare 2 - methoxybenzonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm - free electrolytic cell. Then, 0.3 mmol of 2 - methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n 0.3 mmol of 2 - methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added to a 10 mL cylindrical flask, which was used as a diaphragm - free electrolytic cell. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, air atmosphere, and a constant current of 10 mA, the mixture was stirred at a speed of 600 rpm for 12 h to carry out the electrochemical reaction. After the reaction was completed, the reaction mixture was poured into 30 mL of H2O, extracted three times with 30 mL of ethyl acetate, the combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R fBy reacting (9.9 mg, yellow oil, yield 25%) of the target product II-12 can be obtained when [conditions are met] (e.g., a certain reaction parameter is equal to 0.25).

[0060] 1 H NMR (600 MHz, Chloroform-d) δ 7.55 (t, J = 7.6 Hz, 2H), 7.04–6.96 (m, 2H), 3.93 (s, 3H); 13 C NMR (151 MHz, Chloroform-d) δ 161.2, 134.4, 133.7, 120.8, 116.5, 111.3, 101.8, 56.0.

[0061] Example 13

[0062] To prepare 4-ethoxybenzonitrile, the structural formula of which is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell. Then add 0.3 mmol of 4-ethoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar into the electrolytic cell. Insert two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm each as the anode and cathode (both electrodes are immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, air atmosphere, and a constant current of 10 mA, stir at a speed of 600 rpm for 10 h to carry out an electrochemical reaction. After the reaction is completed, the reaction mixture is obtained. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate. The combined organic layers are washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent is removed by distillation under reduced pressure. Finally, it is purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-13 (19.8 mg, yellow oil, yield 45%).

[0063] 1 H NMR (600 MHz, Chloroform-d) δ 7.57 (d, J = 8.4 Hz, 2H), 6.93 (d, J = 8.4 Hz, 2H), 4.08 (q, J = 7.0 Hz, 2H), 1.44 (t, J = 7.0 Hz, 3H); 13 C NMR (151 MHz, Chloroform-d) δ 162.3, 134.0, 119.3, 115.2, 103.7, 63.9, 14.6.

[0064] Example 14

[0065] To prepare 4-isopropoxybenzonitrile, whose structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 4-isopropylbenzene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar. Insert two platinum sheets with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 10 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, a reaction mixture is obtained. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then remove the solvent by distillation under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-14 (20.3 mg, yellow oil, yield 42%).

[0066] 1 1H NMR (600 MHz, Chloroform-d) δ 7.56 (d, J = 8.5 Hz, 2H), 6.91 (d, J = 8.4 Hz, 2H), 4.61 (h, J = 6.1 Hz, 1H), 1.36 (d, J = 6.1 Hz, 6H); 13 13C NMR (151 MHz, Chloroform-d) δ 161.4, 134.0, 119.4, 116.1, 103.4, 70.4, 21.8.

[0067] Example 15

[0068] To prepare 4-tert-butoxybenzonitrile, whose structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 4-tert-butylbenzene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of nMix 0.3 mmol of 4-isobutoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of tetrabutylammonium tetrafluoroborate ( f Bu4NBF4), 100 μL of H2O, 0.9 mmol of TFA, 5 mL of DMSO / DCE (4:1 v / v) mixed organic solvent and a magnetic stir bar. Insert two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm each as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 10 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, obtain the reaction mixture. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate. Wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then remove the solvent by distillation under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R

[0069] 1 H NMR (600 MHz, Chloroform-d) δ 7.56 (d, J = 8.7 Hz, 2H), 7.04 (d, J = 8.6 Hz, 2H), 1.42 (d, J = 1.1 Hz, 9H); 13 C NMR (151 MHz, Chloroform-d) δ 159.9, 133.4, 123.0, 119.1, 105.7, 80.2, 28.8.

[0070] Example 16

[0071] Prepare 4-isobutoxybenzonitrile, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical bottle as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 4-isobutoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of tetrabutylammonium tetrafluoroborate ( n Bu4NBF4), 100 μL of H2O, 0.9 mmol of TFA, 5 mL of DMSO / DCE (4:1 v / v) mixed organic solvent and a magnetic stir bar. Insert two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm each as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 10 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, obtain the reaction mixture. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate. Wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then remove the solvent by distillation under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, Rf = 0.25), the target product II-16 (22.1 mg, yellow oil, yield 42%) can be obtained.

[0072] 1 H NMR (600 MHz, Chloroform-d) δ 7.59–7.55 (m, 2H), 6.95–6.92 (m, 2H), 3.76 (d, J = 6.5 Hz, 2H), 2.10 (dp, J = 13.3, 6.7 Hz, 1H), 1.03 (d, J = 6.8 Hz, 6H); 13 C NMR (151 MHz, Chloroform-d) δ 162.6, 134.0, 119.4, 115.2, 103.6, 74.7, 28.1, 19.1.

[0073] Example 17

[0074] Prepare 3,4-dimethoxybenzonitrile, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 3,4-dimethoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar. Insert two platinum sheets with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then carry out an electrochemical reaction at room temperature, in an air atmosphere, with a constant current of 10 mA and a stirring speed of 600 rpm / min for 8 h. After the reaction is completed, the reaction mixture is obtained. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layer with 30 mL of saturated NaCl solution, dry it over anhydrous Na2SO4, and then distill off the solvent under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25), the target product II-17 (18.6 mg, yellow oil, yield 38%) can be obtained.

[0075] 1 H NMR (600 MHz, Chloroform-d) δ 7.31–7.25 (m, 1H), 7.08 (t, J = 3.1 Hz, 1H), 6.91 (d, J = 8.3 Hz, 1H), 3.91 (dd, J = 19.6, 4.3 Hz, 6H); 1313C NMR (151 MHz, Chloroform-d) δ 152.9, 149.2, 126.4, 119.2, 114.0, 111.3, 103.9, 56.1, 56.1.

[0076] Example 18

[0077] Prepare piperonal nitrile, whose structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 3,4-(methylenedioxy)toluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of DMSO / DCE (4:1 v / v) mixed organic solvent and a magnetic stir bar, insert two platinum sheets with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 8 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, a reaction mixture is obtained. Pour this reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then distill off the solvent under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-18 (18.0 mg, yellow oil, yield 41%).

[0078] 1 1H NMR (600 MHz, Chloroform-d) δ 7.21 (dd, J = 8.1, 1.6 Hz, 1H), 7.04 (d, J = 1.8 Hz, 1H), 6.87 (d, J = 8.1 Hz, 1H), 6.07 (s, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 151.5, 148.1, 128.2, 118.9, 111.4, 109.1, 105.0, 102.2.

[0079] Example 19

[0080] Prepare 3,4,5-trimethoxybenzonitrile, whose structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 3,4,5-trimethoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of nMix 0.9 mmol of Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar. Insert two platinum sheets each with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 5 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, obtain the reaction mixture. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate. Wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then remove the solvent by distillation under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 10:1, R f = 0.25) to obtain the target product II-19 (17.9 mg, yellow oil, yield 31%).

[0081] 1 1H NMR (600 MHz, Chloroform-d) δ 6.87 (s, 2H), 3.90 (s, 3H), 3.88 (s, 6H); 13 13C NMR (151 MHz, Chloroform-d) δ 153.6, 142.5, 118.9, 109.5, 106.7, 61.0, 56.4.

[0082] Example 20

[0083] Prepare 3-methyl-4-methoxybenzonitrile, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 3-methyl-4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol n of Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar. Insert two platinum sheets each with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 10 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, obtain the reaction mixture. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate. Wash the combined organic layers with 30 mL of saturated NaCl solution, dry over anhydrous Na2SO4, and then remove the solvent by distillation under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f=(0.25), the target product II-20 (18.1 mg, yellow oil, yield 41%) can be obtained.

[0084] 1 H NMR (600 MHz, Chloroform-d) δ 7.49 (dd, J = 8.5, 2.1 Hz, 1H), 7.41–7.38 (m, 1H), 6.85 (d, J = 8.5 Hz, 1H), 3.88 (s, 3H), 2.21 (s, 3H); 13 C NMR (151 MHz, Chloroform-d) δ 161.1, 133.9, 132.0, 128.2, 110.1, 103.4, 55.6, 16.03.

[0085] Example 21

[0086] Prepare 2-methyl-4-methoxybenzonitrile, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical bottle as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 2-methyl-4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of DMSO / DCE (4:1 v / v) mixed organic solvent and a magnetic stir bar, insert two platinum sheets with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm / min for 10 h under the conditions of room temperature, air atmosphere, and constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, the reaction mixture is obtained. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layer with 30 mL of saturated NaCl solution, dry it over anhydrous Na2SO4, and then distill off the solvent under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f =(0.25), the target product II-21 (13.2 mg, yellow oil, yield 30%) can be obtained.

[0087] 1 H NMR (600 MHz, Chloroform-d) δ 7.51 (dd, J = 8.0, 4.2 Hz, 1H), 6.85–6.72 (m, 2H), 3.83 (d, J = 3.6 Hz, 3H), 2.50 (d, J = 3.6 Hz, 3H); 1313C NMR (151 MHz, Chloroform-d) δ 162.8, 144.1, 134.2, 118.5, 115.7, 112.1, 104.5, 55.5, 20.7。

[0088] Example 22

[0089] Prepare 3,5-dimethyl-4-methoxybenzonitrile, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 3,5-dimethyl-4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of n Bu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar, insert two platinum sheets with dimensions of 52 mm × 8 mm × 0.2 mm as the anode and cathode (the two electrodes are immersed 1 cm in the reaction solution), and then stir at a speed of 600 rpm for 11 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction is completed, a reaction mixture is obtained. Pour the reaction mixture into 30 mL of H2O, extract it three times with 30 mL of ethyl acetate, wash the combined organic layer with 30 mL of saturated NaCl solution, dry it over anhydrous Na2SO4, and then distill off the solvent under reduced pressure. Finally, purify it by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-22 (21.7 mg, yellow oil, yield 45%).

[0090] 1 1H NMR (600 MHz, Chloroform-d) δ 7.32 (s, 2H), 3.76 (s, 3H), 2.30 (s, 6H); 13 13C NMR (151 MHz, Chloroform-d) δ 160.8, 132.7, 119.0, 107.3, 59.8, 16.0。

[0091] Example 23

[0092] Prepare 3-fluoro-4-methoxybenzonitrile, and its structural formula is: The specific method is as follows: Select a 10 mL cylindrical flask as a diaphragm-free electrolytic cell, and then add 0.3 mmol of 3-fluoro-4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol of nA mixture of Bu4NBF4 (100 μL), H2O (100 μL), 0.9 mmol of TFA, 5 mL of a DMSO / DCE (4:1 v / v) mixed organic solvent, and a magnetic stir bar was prepared. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, air atmosphere, and a constant current of 10 mA, the mixture was stirred at 600 rpm for 10 h to carry out the electrochemical reaction. After the reaction, the reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-23 (23.1 mg, yellow oil, yield 54%).

[0093] 1 1H NMR (600 MHz, Chloroform-d) δ 7.44 (dt, J = 8.5, 1.6 Hz, 1H), 7.36 (dt, J = 10.6, 1.5 Hz, 1H), 7.03 (t, J = 8.4 Hz, 1H), 3.96 (d, J = 1.1 Hz, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 151.9 (d, J = 9.1 Hz), 151.8 (d, J = 250.6 Hz), 129.7 (d, J = 3.0 Hz), 119.6 (d, J = 21.1 Hz), 118.0 (d, J = 3.0 Hz), 113.6 (d, J = 3.0 Hz), 104.0 (d, J = 7.6 Hz), 56.4; 19 19F NMR (565 MHz, Chloroform-d) δ -132.0; 19 19F NMR (565 MHz, Chloroform-d) δ -132.0。

[0094] Example 24

[0095] To prepare 3-chloro-4-methoxybenzonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 3-chloro-4-methylanisole, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were added. Two platinum plates each with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution), and then the mixture was stirred at a speed of 600 rpm / min for 10 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA to carry out an electrochemical reaction. After the reaction ended, the reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-24 (25.5 mg, yellow oil, yield 51%).

[0096] 1 1H NMR (600 MHz, Chloroform-d) δ 7.66 (d, J = 2.1 Hz, 1H), 7.56 (dd, J = 8.6, 2.1 Hz, 1H), 6.99 (d, J = 8.6 Hz, 1H), 3.97 (s, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 158.6, 133.6, 132.5, 123.6, 117.9, 112.2, 104.8, 56.5.

[0097] Example 25

[0098] To prepare 3-bromo-4-methoxybenzonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell, and then 0.3 mmol of 3-bromo-4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL DMSO / DCE (4:1 v / v) mixed organic solvent and a magnetic stir bar were added. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution), and then stirred at a speed of 600 rpm / min for 10 h under the conditions of room temperature, air atmosphere, and a constant current of 10 mA for the electrochemical reaction. After the reaction was completed, the reaction mixture was obtained. The reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-25 (28.5 mg, yellow oil, yield 45%).

[0099] 1 1H NMR (600 MHz, Chloroform-d) δ 7.82 (d, J = 2.5 Hz, 1H), 7.60 (dd, J = 8.6, 2.2 Hz, 1H), 6.95 (d, J = 8.6 Hz, 1H), 3.96 (s, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 159.5, 136.7, 133.2, 117.7, 112.34, 111.9, 105.3, 56.6.

[0100] Example 26

[0101] To prepare 2-bromo-4-methoxybenzonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell, and then 0.3 mmol of 2-bromo-4-methoxytoluene, 0.9 mmol of hydroxylamine sulfate, 0.3 mmol nBu4NBF4, 100 μL H2O, 0.9 mmol TFA, 5 mL of a DMSO / DCE (4:1 v / v) mixed organic solvent, and a magnetic stir bar were added. Two platinum plates each with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm into the reaction solution). Then, under the conditions of room temperature, an air atmosphere, and a constant current of 10 mA, stirring was carried out at a speed of 600 rpm / min for 10 h to conduct an electrochemical reaction. After the reaction ended, a reaction mixture was obtained. The reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 20:1, R f = 0.25) to obtain the target product II-26 (27.8 mg, yellow oil, yield 44%).

[0102] 1 1H NMR (600 MHz, Chloroform-d) δ 7.56 (d, J = 8.7 Hz, 1H), 7.18 (d, J = 2.5 Hz, 1H), 6.91 (dd, J = 8.7, 2.5 Hz, 1H), 3.87 (s, 3H); 13 13C NMR (151 MHz, Chloroform-d) δ 163.2, 135.3, 126.5, 118.7, 117.6, 114.0, 107.5, 56.0.

[0103] Example 27

[0104] To prepare 4-phenoxybenzonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 4-phenoxytoluene, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol of nA mixture of Bu4NBF4 (100 μL), H2O (100 μL), TFA (0.9 mmol), 5 mL of a DMSO / DCE (4:1 v / v) mixed organic solvent, and a magnetic stir bar was prepared. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution). Then, under the conditions of room temperature, an air atmosphere, and a constant current of 10 mA, the mixture was stirred at 600 rpm / min for 10 h to carry out the electrochemical reaction. After the reaction was completed, the reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, purification by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) afforded the target product II-27 (31.0 mg, yellow oil, yield 53%).

[0105] 1 1H NMR (600 MHz, Chloroform-d) δ 7.59 (d, J = 8.5 Hz, 2H), 7.41 (t, J = 7.7 Hz, 2H), 7.27–7.21 (m, 1H), 7.06 (d, J = 7.9 Hz, 2H), 7.00 (d, J = 8.4 Hz, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 161.7, 154.9, 134.1, 130.3, 125.2, 120.4, 118.8, 118.0, 105.9.

[0106] Example 28

[0107] To prepare 2-naphthonitrile, the structural formula of which is: The specific method is as follows: A 10 mL cylindrical flask was selected as a diaphragm-free electrolytic cell. Then, 0.3 mmol of 2-methylnaphthalene, 0.9 mmol of hydroxylamine sulfate, and 0.3 mmol nBu4NBF4, 100 μL of H2O, 0.9 mmol of TFA, 5 mL of a mixed organic solvent of DMSO / DCE (4:1 v / v), and a magnetic stir bar were taken. Two platinum plates with dimensions of 52 mm × 8 mm × 0.2 mm were inserted as the anode and cathode (the two electrodes were immersed 1 cm in the reaction solution), and then stirred at a speed of 600 rpm for 12 h under the conditions of room temperature, air atmosphere, and a constant current of 20 mA to carry out an electrochemical reaction. After the reaction ended, a reaction mixture was obtained. The reaction mixture was poured into 30 mL of H2O and extracted three times with 30 mL of ethyl acetate. The combined organic layers were washed with 30 mL of saturated NaCl solution, dried over anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. Finally, it was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1, R f = 0.25) to obtain the target product II-28 (128.9 mg, yellow oil, yield 60%).

[0108] 1 1H NMR (600 MHz, Chloroform-d) δ 8.19 (s, 1H), 7.90–7.83 (m, 3H), 7.63 (t, J = 7.5 Hz, 1H), 7.58 (dd, J = 12.2, 7.9 Hz, 2H); 13 13C NMR (151 MHz, Chloroform-d) δ 134.7, 134.1, 132.3, 129.2, 129.1, 128.4, 128.1, 127.7, 126.3, 119.3, 109.4.

[0109] Figure 1 The following is the possible reaction mechanism for the electrochemical oxidation of methylarene to aryl nitrile involved in the above examples. From Figure 1 it can be seen that methylarene 1 is first oxidized at the anode to generate a cation radical intermediate A, then oxidized and deprotonated to obtain a benzylic carbocation intermediate B, then reacts with water to generate intermediate alcohol C, alcohol is oxidized to aldehyde D, then reacts with hydroxylamine to generate aldoxime E, aldoxime is oxidized to generate an oxidized nitrile intermediate F, and finally reduced to obtain the target product nitrile 3.

[0110] Performance Test

[0111] 1. Explore the effect of electrode materials on the electrochemical oxidation of methylarene to aryl nitrile

[0112] The effect of electrode materials on the electrochemical oxidation of methylarene to aryl nitrile was explored according to the following reaction formula. During the experiment, only the anode material and cathode material of the diaphragm-free electrolytic cell were changed, and the types and amounts of other substances participating in the reaction, the current magnitude, temperature, and air atmosphere conditions were kept unchanged. The experimental results are shown in Table 1.

[0113]

[0114] Table 1 Comparison of the effects of different electrode materials on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0115]

[0116] As can be seen from Table 1, different electrode materials result in different contents of aromatic nitriles formed by the electrochemical oxidation of methylaromatics. When both the anode and cathode materials are platinum, the yield of aromatic nitriles is the highest.

[0117] 2. Explore the effect of organic solvents on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0118] The effect of organic solvents on the electrochemical oxidation of methylaromatics to form aromatic nitriles was explored according to the following reaction formula. During the experiment, only the type of organic solvent was changed, while keeping the types and amounts of other substances participating in the reaction in the diaphragm-free electrolytic cell, the current magnitude, the temperature, the air atmosphere, and the electrode material conditions unchanged. The experimental results are shown in Table 2.

[0119]

[0120] Table 2 Comparison of the effects of different organic solvents on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0121]

[0122] As can be seen from Table 2, different types of organic solvents result in different contents of aromatic nitriles formed by the electrochemical oxidation of methylaromatics. When the organic solvent is a mixture of dimethyl sulfoxide and dichloroethane with a volume ratio of 4:1, the yield of aromatic nitriles is the highest.

[0123] 3. Explore the effect of electrolytes on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0124] The effect of electrolytes on the electrochemical oxidation of methylaromatics to form aromatic nitriles was explored according to the following reaction formula. During the experiment, only the type of electrolyte was changed, while keeping the types and amounts of other substances participating in the reaction in the diaphragm-free electrolytic cell, the current magnitude, the temperature, the air atmosphere, and the electrode material conditions unchanged. The experimental results are shown in Table 3.

[0125]

[0126] Table 3 Comparison of the effects of different electrolytes on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0127]

[0128] As can be seen from Table 3, different types of electrolytes result in different contents of aromatic nitriles formed by the electrochemical oxidation of methylaromatics. When the electrolyte is tetrabutylammonium tetrafluoroborate, the yield of aromatic nitriles is the highest.

[0129] 4. Explore the influence of acidic substances on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0130] Explore the influence of acidic substances on the electrochemical oxidation of methylaromatics to form aromatic nitriles according to the following reaction formula. During the experiment, only the types and addition amounts of acidic substances were changed, while keeping the types and amounts of other substances participating in the reaction, the current magnitude, temperature, air atmosphere, and electrode material conditions in the diaphragmless electrolytic cell unchanged. The experimental results are shown in Table 4

[0131]

[0132] Table 4 Comparison of the influence of the types and addition amounts of acidic substances on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0133]

[0134] As can be seen from Table 4, when the types and addition amounts of acidic substances are different, the contents of aromatic nitriles formed by the electrochemical oxidation of methylaromatics are also different. When the acidic substance is trifluoroacetic acid and the equivalent is 3, the yield of aromatic nitriles is the highest

[0135] 5. Explore the influence of the feeding amounts of hydroxylamine sulfate and water on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0136] Explore the influence of the feeding amounts of hydroxylamine sulfate and water on the electrochemical oxidation of methylaromatics to form aromatic nitriles according to the following reaction formula. During the experiment, only the feeding amounts of hydroxylamine sulfate and water were changed, while keeping the types and amounts of other substances participating in the reaction, the current magnitude, temperature, air atmosphere, and electrode material conditions in the diaphragmless electrolytic cell unchanged. The experimental results are shown in Table 5

[0137]

[0138] Table 5 Comparison of the influence of the feeding amounts of hydroxylamine sulfate and water on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0139]

[0140]

[0141] As can be seen from Table 5, when the feeding amounts of hydroxylamine sulfate and water are different, the contents of aromatic nitriles formed by the electrochemical oxidation of methylaromatics are also different. When the feeding amount of hydroxylamine sulfate is 3 equiv. and the feeding amount of water is 100 μL, the yield of aromatic nitriles is the highest

[0142] 6. Explore the influence of current magnitude on the electrochemical oxidation of methylaromatics to form aromatic nitriles

[0143] The influence of current magnitude on the electrochemical oxidation of methylarene to generate aromatic nitrile was investigated according to the following reaction formula. During the experiment, the types and amounts of substances participating in the reaction, temperature, air atmosphere, and electrode material conditions in the diaphragm-free electrolytic cell were kept unchanged, and only the current magnitude was changed. The experimental results are shown in Table 6.

[0144]

[0145] Table 6 Comparison of the influence of current magnitude on the electrochemical oxidation of methylarene to generate aromatic nitrile

[0146]

[0147] As can be seen from Table 6, when the current magnitude is different, the content of aromatic nitrile generated by the electrochemical oxidation of methylarene is also different. When the current is 20 mA, the yield of aromatic nitrile is the highest.

[0148] In summary, the present invention provides a method for electrochemically synthesizing aromatic nitrile from methylarene. This method uses abundant methylarene as the raw material and realizes the preparation of aromatic nitrile compounds through an electrochemical reaction with hydroxylamine sulfate in an electrolytic cell. By regulating the types of electrode materials, organic solvents, electrolytes, acidic substances, current magnitude, and the feeding ratio of hydroxylamine sulfate to water in the diaphragm-free electrolytic cell, the yield of aromatic nitrile is greatly improved. Since no transition metal catalyst needs to be introduced during the preparation process, hydroxylamine, which is safe, non-toxic, and inexpensive and easily available, is used as the nitrogen source, and the conversion of methylarene to aromatic nitrile can be directly achieved, it is a green, simple, and efficient nitrile preparation method.

[0149] 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 preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for electrochemically synthesizing aromatic nitriles from methyl aromatics, characterized in that: The method is as follows: Place methylarene, hydroxylamine sulfate, electrolyte, deionized water, acidic substance and organic solvent in a diaphragmless electrolytic cell, insert an anode and a cathode, and then stir for 5 - 22 h under the conditions of room temperature, air atmosphere and constant current to carry out an electrochemical reaction. After the reaction is completed, a reaction mixture is obtained. The reaction mixture can be obtained to obtain aromatic nitrile after extraction, washing, drying, desolvation and purification in sequence; The methylarene is any one of 2 - methylnaphthalene, 4 - methylbiphenyl, 2 - methylbiphenyl, 4 - methyl - 4'-methylbiphenyl, 4 - methyl - 3',5'-dimethylbiphenyl, 4 - methyl - 4'-ethylbiphenyl, 4 - methyl - 4'-fluorobiphenyl, 4 - methyl - 4'-chlorobiphenyl, 4 - methyl - 4'-bromobiphenyl, 4 - methyl - 4'-ethoxybiphenyl, 4 - methyl - 4'-propoxybiphenyl, 4 - methoxytoluene, 2 - methoxytoluene, 4 - ethoxytoluene, 4 - isopropoxytoluene, 4 - tert - butoxytoluene, 4 - isobutoxytoluene, 3,4 - dimethoxytoluene, 3,4-(methylenedioxy)toluene, 3,4,5 - trimethoxytoluene, 3 - methyl - 4 - methoxytoluene, 2 - methyl - 4 - methoxytoluene, 3,5 - dimethyl - 4 - methoxytoluene, 3 - fluoro - 4 - methoxytoluene, 3 - chloro - 4 - methoxytoluene, 2 - bromo - 4 - methoxytoluene, 3 - bromo - 4 - methoxytoluene, or 4 - phenoxytoluene.

2. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, wherein: The electrolyte is any one of tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, tetraethylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, sodium tetrafluoroborate, sodium perchlorate, lithium perchlorate, tetraethylammonium perchlorate, tetrabutylammonium perchlorate, potassium hexafluorophosphate, tetrabutylammonium trifluoromethanesulfonate or tetraethylammonium methanesulfonate.

3. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, characterized in that: The acidic substance is any one of trifluoroacetic acid, acetic acid, boric acid or boron trifluoride diethyl etherate.

4. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, characterized in that: The organic solvent is any one of dimethyl sulfoxide, dichloromethane, dichloroethane, a mixed solution formed by dimethyl sulfoxide and dichloroethane or hexafluoroisopropanol.

5. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, wherein: The material of the anode is any one of platinum or carbon; the material of the cathode is any one of nickel foam, copper foam, carbon or platinum.

6. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, characterized in that: The constant current is 10 - 120 mA.

7. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, characterized in that: The molar ratio of the methylarene to the hydroxylamine sulfate is 1:1.5 - 1:4; the molar ratio of the methylarene to the electrolyte is 1:1 - 1:1.5; the molar volume ratio of the methylarene to the deionized water is 1:167 - 1:300, mmol:mL; the molar ratio of the methylarene to the acidic substance is 1:1.5 - 1:4; the molar volume ratio of the methylarene to the organic solvent is 1:4 - 1:16.7, mmol:mL.

8. The method for electrochemically synthesizing aromatic nitriles from methyl aromatics according to claim 1, characterized in that: The stirring speed is 600 - 700 rpm / min.

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