1. A process for preparing N-substituted pyrrolidone derivatives, which comprises: the method comprises the following steps: adding a benzoic acid compound shown in the following formula (I) and an amine compound shown in the following formula (II) into an electrolytic system for reaction to prepare an N-substituted pyrrolidone derivative shown in the following formula (III);

wherein R is¹、R²Are independently selected from one of aryl, alkyl and halogen atoms; r¹And R²The same or different;

the electrolytic system comprises an electrolyte and a solvent, wherein the electrolyte comprises a butyl ammonium compound.

2. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: said aryl group comprising C₂₀The following aryl groups; preferably, the aryl group includes one of an alkylphenyl group, an alkoxyphenyl group, a nitrophenyl group, a halophenyl group and a heteroaryl group;

preferably, the alkylphenyl group comprises a mono-or di-substituted alkylphenyl group; preferably, the alkylphenyl group includes C_7～14An alkyl phenyl group of (a); preferably, the alkylphenyl group includes tolyl and tert-butylphenyl;

preferably, the alkoxyphenyl group comprises C_7～10An alkoxyphenyl group of (a);

preferably, the halophenyl group comprises a mono-substituted halophenyl group or a di-substituted halophenyl group; preferably, the halo comprises phenyl F, phenyl Cl or phenyl Br; preferably, in the disubstituted halophenyl group, the substituents are the same or different;

preferably, said heteroaryl means C₁₀A heterocycle containing at least one of N and O; preferably, the heteroaryl group comprises C₁₂The following conjugated heterocyclic ring; preferably, the heteroaryl group comprises a pyridine ring or a furan ring.

3. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the alkyl group includes C₂₀The following alkyl groups; preferably, the alkyl group comprises one of methyl, ethyl, propyl and butyl; preferably, the halogen atom includes one of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

4. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the amine compound comprises at least one of aniline, p-methylaniline, p-butylaniline, p-tert-butylaniline, cycloheptylamine, cyclohexylamine, cyclopentylamine, hexylamine, p-fluoroaniline, p-bromoaniline, p-methoxyaniline, p-trifluoromethoxy aniline, p-phenoxyaniline, m-methoxyaniline, m-trifluoromethoxyaniline, o-methylaniline, o-methoxyaniline, o-hydroxyaniline, m-dimethylaniline, o-dimethylaniline and phenethylamine; preferably, the benzoic acid-based compound comprises at least one of o-formylbenzoic acid, p-methylanthroylbenzoic acid, m-methylanthroylbenzoic acid, p-phenylanthroylbenzoic acid, and haloo-formylbenzoic acid; more preferably, the halogenated anthranilic acid comprises at least one of 4-chloro-1-formyl-2-benzoic acid and 4-bromo-1-formyl-2-benzoic acid.

5. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the butyl ammonium compound comprises at least one of tetra-n-butyl ammonium iodide, tetra-n-butyl ammonium acetate, tetra-n-butyl amine borate, tetra-n-butyl amine phosphonate and tetra-n-butyl amine bisulfate; preferably, the butylammonium compound is tetra-n-butylhydrogensulfate.

6. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the molar ratio of the benzoic acid compound to the electrolyte is 1: 0.5-2; preferably, the molar ratio of the benzoic acid compound to the electrolyte is 1: 0.5-1.

7. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the molar ratio of the benzoic acid compound to the amine compound is 1: 1-2; preferably, the molar ratio of the benzoic acid compound to the amine compound is 1: 2.

8. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the solvent comprises at least one of dimethyl sulfoxide, acetonitrile, N-pyrrolidone, N-dimethylformamide, dichloromethane and tetrahydrofuran; preferably, the solvent is a mixed solution of dichloromethane and N, N-dimethylformamide; preferably, the solvent is N, N-dimethylformamide.

9. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the volume mol ratio of the solvent to the benzoic acid compound is 0.5 mL/mmol-2 mL/mmol; preferably, the volume mol ratio of the solvent to the benzoic acid compound is 0.5 mL/mmol-1 mL/mmol.

10. A process for preparing an N-substituted pyrrolidone derivative according to claim 1, wherein: the reaction adopts direct current; preferably, the direct current is 7 mA-10 mA, and the reaction time is 3 h-5 h; preferably, the temperature of the reaction is 20 ℃ to 30 ℃.

Background

Pyrrolidone derivatives are important building blocks in organic chemistry and find application in a variety of dissolved oxygen main components, such as surfactants, intermediates for inks, fibers and drugs. N-substituted pyrrolidone derivatives are attracting attention for their wide application in the fields of solvents, surfactants, pharmaceutical statins, etc., and their utilization in the field of biological value-added. However, the synthesis method in the related art is complicated.

Therefore, there is a need to develop a method for preparing N-substituted pyrrolidone derivatives, which is efficient and environmentally friendly.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for preparing the N-substituted pyrrolidone derivative through electrocatalysis can synthesize the N-substituted pyrrolidone compound efficiently and environmentally.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a process for the preparation of an N-substituted pyrrolidone derivative comprising the steps of: adding a benzoic acid compound shown in the following formula (I) and an amine compound shown in the following formula (II) into an electrolytic system for reaction to prepare an N-substituted pyrrolidone derivative shown in the following formula (III);

wherein R is¹、R²Are independently selected from one of aryl, alkyl and halogen atoms; r¹And R²The same or different;

the electrolytic system comprises an electrolyte and a solvent;

the electrolyte includes a butylammonium compound.

Electrochemical techniques are a class of processes that can achieve heterocyclic synthesis by using anodic oxidation instead of stoichiometric oxidant addition. The use of metals and stoichiometric oxidants is reduced, and an environmentally friendly method for synthesizing N-substituted pyrrolidone derivatives is developed.

According to some embodiments of the invention, the aryl group comprises C₂₀The following aryl groups.

According to some embodiments of the invention, the aryl group comprises one of an alkyl phenyl group, an alkoxy phenyl group, a nitro phenyl group, a halo phenyl group and a heteroaryl group.

According to some embodiments of the invention, the alkyl-phenyl group comprises a mono-or di-substituted alkyl-phenyl group.

According to some embodiments of the invention, the alkylbenzene isThe radicals including C_7～14An alkyl phenyl group of (1).

According to some embodiments of the invention, the alkylphenyl group includes tolyl and tert-butylphenyl.

According to some embodiments of the invention, the alkoxyphenyl comprises C_7～10An alkoxyphenyl group of (1).

According to some embodiments of the invention, the halogenated phenyl group comprises a mono-substituted halogenated phenyl group or a di-substituted halogenated phenyl group.

According to some embodiments of the invention, the halogenated phenyl comprises phenyl F, phenyl Cl, or phenyl Br; preferably, in the disubstituted halophenyl group, the substituents are the same or different.

According to some embodiments of the invention, the heteroaryl refers to C₁₀The following heterocyclic ring containing at least one of N and O.

According to some embodiments of the invention, the heteroaryl comprises C₁₂The following conjugated heterocyclic ring.

According to some embodiments of the invention, the heteroaryl group comprises a pyridine ring or a furan ring.

According to some embodiments of the invention, the alkyl group comprises C₂₀The following alkyl groups.

According to some embodiments of the invention, the alkyl group comprises one of methyl, ethyl, propyl and butyl.

According to some embodiments of the invention, the halogen atom comprises one of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

According to some embodiments of the invention, the amine compound comprises at least one of aniline, p-methylaniline, p-butylaniline, p-tert-butylaniline, cycloheptylamine, cyclohexylamine, cyclopentylamine, hexylamine, p-fluoroaniline, p-bromoaniline, p-methoxyaniline, p-trifluoromethoxy aniline, p-phenoxyaniline, m-methoxyaniline, m-trifluoromethoxy aniline, o-methylaniline, o-methoxyaniline, o-hydroxyaniline, m-dimethylaniline, o-dimethylaniline and phenethylamine.

According to some embodiments of the invention, the benzoic acid-based compound comprises at least one of o-formylbenzoic acid, p-methylanthrylbenzoic acid, m-methylanthrylformylbenzoic acid, p-phenylanthrylformylbenzoic acid and haloanthranilic-formylbenzoic acid.

According to some embodiments of the invention, the halogenated anthranilic acid comprises at least one of 4-chloro-1-formyl-2-benzoic acid and 4-bromo-1-formyl-2-benzoic acid.

According to some embodiments of the invention, the butylammonium compound comprises at least one of tetra-n-butylammonium iodide, tetra-n-butylammonium acetate, tetra-n-butylammonium borate, tetra-n-butylphosphonic acid amine, and tetra-n-butylhydrogen ammonium sulfate.

The addition of the butylamine compounds greatly improves the yield of the target product while providing a conductive effect.

According to some embodiments of the invention, the butylammonium compound is tetra-n-butylhydrogensulfate.

According to some embodiments of the invention, the molar ratio of the benzoic acid compound to the electrolyte is 1: 0.5-2; preferably, the molar ratio of the benzoic acid compound to the electrolyte is 1: 0.5-1.

According to some embodiments of the invention, the molar ratio of the benzoic acid compound to the amine compound is 1: 1-2; preferably, the molar ratio of the benzoic acid compound to the amine compound is 1: 2.

According to some embodiments of the invention, the solvent comprises at least one of dimethylsulfoxide, acetonitrile, N-pyrrolidone, N-dimethylformamide, dichloromethane, and tetrahydrofuran; preferably, the solvent is a mixed solution of dichloromethane and N, N-dimethylformamide; preferably, the solvent is N, N-dimethylformamide.

According to some embodiments of the invention, the solvent to benzoic acid compound volume molar ratio is from 0.5mL/mmol to 2 mL/mmol; preferably, the volume mol ratio of the solvent to the benzoic acid compound is 0.5 mL/mmol-1 mL/mmol.

According to some embodiments of the invention, the electrolytic system further comprises a cathode and an anode.

According to some embodiments of the invention, the anode comprises a platinum sheet, a RVC (glassy carbon electrode), and a carbon rod; preferably, the anode is a carbon rod.

The carbon rod is the simplest and most efficient.

According to some embodiments of the invention, the cathode comprises a copper sheet and a carbon rod; preferably, the cathode is a carbon rod.

The cathode and the anode are selected from carbon rods, which is the simplest and most efficient.

According to some embodiments of the invention, the reaction is performed using a direct current; preferably, the direct current is 7 mA-10 mA, and the reaction time is 3 h-5 h.

According to some embodiments of the invention, the temperature of the reaction is between 20 ℃ and 30 ℃.

According to some embodiments of the invention, the ratio of the reaction time to the molar amount of benzoic acid compound is 0.5 to 1 hour/mmol.

According to some embodiments of the invention, after the reaction is completed, the N-substituted pyrrolidone derivative is obtained by washing, extraction, concentration and column chromatography.

According to some embodiments of the invention, the extraction, extractant, and solvent comprise ethyl acetate.

The method for preparing the N-substituted pyrrolidone derivative according to the embodiment of the invention has at least the following beneficial effects: the invention provides an electrocatalytic preparation method without an external oxidant, which is characterized in that an amine compound and a benzoic acid compound are utilized to synthesize an N-substituted pyrrolidone derivative in one step through electrocatalytic reaction. The method has high yield, does not need to use a metal catalyst and an external oxidant, is green and environment-friendly, and has low price; the electrolysis system and the reaction raw materials used in the reaction have low price, the post-treatment is simple and convenient, and the method is suitable for industrial production; the method has the advantages of mild reaction conditions, simple operation and high yield.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

In order to explain the technical content, the objects and the effects of the present invention in detail, the following description will be given with reference to the embodiments. The test methods used in the examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are commercially available reagents and materials unless otherwise specified.

Example 1: synthesis of 2-phenylisoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 70mg (0.75mmol) of aniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature (about 25 ℃ C.) and 10mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 81%.

The characterization data of the product are:

¹H NMR(500MHz,CDCl₃)δ＝7.92(d,J＝7.6Hz,1H),7.86(dd,J＝8.6,1.2Hz,2H),7.59(td,J＝7.4,1.2Hz,1H),7.53-7.47(m,2H),7.42(dd,J＝8.7,7.3Hz,2H),7.20-7.13(m,1H),4.83(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝167.6,140.1,139.5,133.2,132.1,129.2,128.4,124.5,124.2,122.7,119.5,50.8.

HRMS(ESI)(m/z):calcd for C₁₄H₁₂NO[M+H]⁺:210.0913,found:210.0920.

example 2: synthesis of 2- (p-tolyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 107mg (1mmol) of p-methylaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 83%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d(CDCl₃))δ＝7.95-7.91(m,1H),7.74(d,J＝5.8Hz,2H),7.58(dt,J＝7.4,3.8Hz,1H),7.51(d,J＝6.8Hz,2H),4.80(s,2H),2.36(s,3H).

¹³C NMR(126MHz,CDCl₃)δ＝167.4,140.2,137.0,134.2,133.3,132.0,129.7,128.3,124.0,122.6,119.6,50.9,20.9.

HRMS(ESI)(m/z):calcd for C₁₅H₁₄NO[M+H]⁺:224.1070,found:224.1074.

example 3: synthesis of 2- (4-butylphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 112mg (0.75mmol) of p-N-butylaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 7mA for 5 hours while using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 60%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.94(dd,J＝7.2,1.4Hz,1H),7.79-7.76(m,2H),7.62-7.59(m,1H),7.53(d,J＝7.6Hz,2H),7.27-7.25(m,2H),4.85(s,2H),2.66-2.62(m,2H),1.66-1.61(m,2H),1.42-1.37(m,2H),0.96(t,J＝7.4Hz,3H).

¹³C NMR(126MHz,CDCl₃)δ＝167.4,140.2,139.3,137.1,133.4,131.9,129.1,128.3,124.1,122.6,119.6,50.9,35.1,33.6,22.3,14.0.

HRMS(ESI)(m/z):calcd for C₁₈H₂₀NO[M+H]⁺:266.1539,found:266.1534.

example 4: synthesis of 2- (4-tert-butylphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 89mg (0.6mmol) of p-tert-butylaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours while using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 84%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.95(d,J＝7.5Hz,1H),7.81-7.79(m,2H),7.63-7.60(m,1H),7.55-7.51(m,2H),7.49-7.46(m,2H),4.88(s,2H),1.37(s,9H).

¹³C NMR(126MHz,CDCl₃)δ＝167.4,147.5,140.2,136.9,133.3,131.9,128.4,126.0,124.1,122.6,119.4,50.8,34.4,31.4.

HRMS(ESI)(m/z):calcd for C₁₈H₂₀NO[M+H]⁺:266.1539,found:266.1533.

example 5: synthesis of 2- (4-fluorophenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 89mg (0.8mmol) of p-fluoroaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 4 hours while using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 57%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.93(d,J＝7.3Hz,1H),7.86-7.81(m,2H),7.62(t,J＝7.4Hz,1H),7.53(d,J＝7.3Hz,2H),7.13(t,J＝8.6Hz,2H),4.84(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝167.4,159.5,140.0,135.6,133.0,132.2,128.5,124.2,122.7,121.3,121.2,115.9,115.8,51.0.

HRMS(ESI)(m/z):calcd for C₁₄H₁₀NOFNa[M+Na]⁺:250.0639,found:250.0637.

example 6: synthesis of 2- (4-bromophenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 172mg (1mmol) of p-bromoaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 7mA for 4 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 45%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.95-7.90(m,1H),7.79(d,J＝8.9Hz,2H),7.61(t,J＝7.4Hz,1H),7.56-7.49(m,4H),4.84(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝167.6,139.9,138.6,132.9,132.4,132.13,128.6,124.3,122.7,120.7,117.2,50.6.

HRMS(ESI)(m/z):calcd for C₁₄H₁₀NOBrNa[M+Na]⁺:309.9838,found:309.9840.

example 7: synthesis of 2- (4-methoxyphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 123mg (1mmol) of p-anisidine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 7mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 48%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.95-7.88(m,1H),7.78-7.71(m,2H),7.58(td,J＝7.4,1.2Hz,1H),7.54-7.47(m,2H),7.00-6.94(m,2H),4.81(s,2H),3.83(s,3H).

¹³C NMR(126MHz,CDCl₃)δ＝167.3,156.7,140.2,133.3,132.7,131.8,128.3,124.0,122.6,121.5,114.4,55.5,51.2.

HRMS(ESI)(m/z):calcd for C₁₅H₁₄NO₂[M+H]⁺:240.1019,found:240.1016.

example 8: synthesis of 2- (4- (trifluoromethoxy) phenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 160mg (0.9mmol) of p-trifluoromethoxyaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 10mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 82%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.92(dd,J＝8.7,6.8Hz,3H),7.64-7.60(m,1H),7.52(dd,J＝7.9,6.8Hz,2H),7.32-7.27(m,2H),4.86(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝167.6,145.4,139.9,138.2,132.9,132.40,128.6,125.3,124.3,122.3,120.4,119.5,50.7.

HRMS(ESI)(m/z):calcd for C₁₅H₁₁NOF₃[M+H]⁺:294.0736,found:294.0733.

example 9: synthesis of 2- (4- (phenoxy) phenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 148mg (0.8mmol) of p-phenoxyaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 85%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.96-7.89(m,1H),7.86-7.75(m,2H),7.60(td,J＝7.3,1.2Hz,1H),7.52(d,J＝7.3Hz,2H),7.34(dd,J＝8.6,7.3Hz,2H),7.16-7.06(m,3H),7.06-6.91(m,2H),4.86(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝167.4,157.4,153.8,140.1,135.0,133.2,132.0,129.8,128.4,124.2,123.2,122.6,121.3,119.7,118.6,51.0.

HRMS(ESI)(m/z):calcd for C₂₀H₁₆NO₂[M+H]⁺:302.1176,found:302.1173.

example 10: synthesis of 2- (3- (trifluoromethoxy) phenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 177mg (1mmol) of m-trifluoromethoxyaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 83%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.97-7.92(m,2H),7.81(ddd,J＝8.4,2.2,0.9Hz,1H),7.64(td,J＝7.3,1.1Hz,1H),7.57-7.53(m,2H),7.46(t,J＝8.3Hz,1H),7.06(ddd,J＝8.1,2.3,1.1Hz,1H),4.88(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝175.1,167.7,149.8(q,J＝8.3Hz),140.9,139.9,132.8,132.5,130.2,128.6,124.3,119.8,116.4,112.0,50.6.

HRMS(ESI)(m/z):calcd for C₁₅H₁₁NOF₃[M+Na]⁺:316.0556,found:316.0562.

example 11: synthesis of 2- (2-methoxyphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 123mg (1mmol) of o-anisidine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 7mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing a solvent by reduced pressure distillation, and performing column chromatography to obtain a product, wherein the yield is 40%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝8.11(dd,J＝7.6,1.4Hz,1H),7.53-7.46(m,2H),7.42(td,J＝7.4,1.6Hz,1H),6.87(ddd,J＝7.6,5.1,3.9Hz,1H),6.83(dd,J＝3.9,1.0Hz,2H),6.76(dt,J＝7.3,1.1Hz,1H),4.59(s,2H),3.85(s,3H).

¹³C NMR(126MHz,CDCl₃)δ＝170.0,148.1,139.1,136.1,132.8,132.5,129.7,128.0,122.7,121.2,113.4,110.0,55.6,48.6.

HRMS(ESI)(m/z):calcd for C₁₅H₁₄NO₂[M+H]⁺:240.1019,found:240.1027.

example 12: synthesis of 2- (2-hydroxyphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 75mg (0.6mmol) of o-hydroxyaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 10mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 77%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝8.80(s,1H),7.95(d,J＝7.7Hz,1H),7.65(t,J＝7.5Hz,1H),7.56(t,J＝6.9Hz,2H),7.24(d,J＝7.6Hz,2H),7.17-7.13(m,1H),7.01(td,J＝7.5,1.4Hz,1H),4.98(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝168.8,150.8,141.8,132.5,131.8,128.7,128.1,127.4,124.4,122.7,122.4,121.2,121.0,52.6.

HRMS(ESI)(m/z):calcd for C₁₄H₁₂NO₂[M+H]⁺:226.0863,found:226.0863.

example 13: synthesis of 2- (2, 6-dimethylphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 97mg (0.8mmol) of o-dimethylaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 3 hours while using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 45%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.98(d,J＝7.5Hz,1H),7.65-7.59(m,1H),7.54(dd,J＝10.4,7.6Hz,2H),7.22(dd,J＝8.6,6.4Hz,1H),7.16(d,J＝7.5Hz,2H),4.60(s,2H),2.20(s,6H).

¹³C NMR(126MHz,CDCl₃)δ＝167.8,141.7,136.8,135.5,132.4,131.7,128.6,128.5,128.3,124.4,123.0,51.2,18.0.

HRMS(ESI)(m/z):calcd for C₁₆H₁₆NO[M+H]⁺:238.1226,found:238.1223.

example 14: synthesis of 2- (3, 5-dimethylphenyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 121mg (1mmol) of m-dimethylaniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 65%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.95-7.89(m,1H),7.59(td,J＝7.4,1.2Hz,1H),7.52-7.47(m,4H),6.84(s,1H),4.84(s,2H),2.36(s,6H).

¹³C NMR(126MHz,CDCl₃)δ＝167.5,140.2,139.4,138.8,133.4,132.0,128.3,126.4,124.1,122.6,117.6,51.0,21.6.

HRMS(ESI)(m/z):calcd for C₁₆H₁₆NO[M+H]⁺:238.1226,found:238.1222.

example 15: synthesis of 2-hexylisoindolin-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 91mg (0.9mmol) of hexylamine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 4 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 82%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.84(dd,J＝7.6,1.2Hz,1H),7.52(td,J＝7.4,1.2Hz,1H),7.49-7.40(m,2H),4.37(s,2H),3.61(t,J＝7.4Hz,2H),1.70-1.62(m,2H),1.38-1.28(m,6H),0.90-0.85(m,3H).

¹³C NMR(126MHz,CDCl₃)δ＝168.5,141.11,133.1,131.1,128.0,123.7,122.6,49.9,42.4,31.6,28.4,26.6,22.6,14.1.

HRMS(ESI)(m/z):calcd for C₁₄H₂₀NO[M+H]⁺:218.1539,found:218.1540.

example 16: synthesis of 2-cyclopentyl isoindoline-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 85mg (1mmol) of cyclopentylamine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 78%.

The characterization data of the product are:

¹H NMR(500MHz,CDCl3)δ＝7.87-7.85(m,1H),7.55-7.52(m,1H),7.49-7.46(m,2H),4.80(p,J＝8.0Hz,1H),4.38(s,2H),2.06-2.01(m,2H),1.84-1.79(m,2H),1.74-1.66(m,4H).

¹³C NMR(126MHz,CDCl₃)δ＝168.5,141.1,133.3,131.0,128.0,123.5,122.7,52.5,46.1,30.1,24.1.

HRMS(ESI)(m/z):calcd for C₁₃H₁₆NO[M+H]⁺:202.1226,found:202.1232.

example 17: synthesis of 2-cyclohexyl isoindoline-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 99mg (1mmol) of cyclohexylamine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 70%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.84(dd,J＝7.9,1.5Hz,1H),7.54-7.49(m,1H),7.49-7.41(m,2H),4.48-4.42(m,1H),4.37(s,2H),1.76-1.56(m,12H).

¹³C NMR(126MHz,CDCl₃)δ＝167.9,141.3,133.4,131.0,128.0,123.6,122.7,50.5,46.0,31.4,25.6,25.6.

HRMS(ESI)(m/z):calcd for C₁₄H₁₈NO[M+H]⁺:216.1383,found:216.1387.

example 18: synthesis of N- (3, 4-dichloro-o-formylbenzoic acid) -5-o-formylbenzoic acid oxazole-2-amine:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 113mg (1mmol) of cycloheptylamine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing a solvent by reduced pressure distillation, and performing column chromatography to obtain a product, wherein the yield is 40%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.84(dd,J＝7.9,1.5Hz,1H),7.54-7.49(m,1H),7.49-7.41(m,2H),4.48-4.42(m,1H),4.37(s,2H),1.76-1.56(m,12H).

¹³C NMR(126MHz,CDCl₃)δ＝181.3,141.3,133.3,131.0,1278.0,123.6,122.7,52.5,46.0,33.7,27.8,24.8.

HRMS(ESI)(m/z):calcd for C₁₅H₂₀NO[M+H]⁺:230.1539,found:230.1547.

example 19: synthesis of 2-benzylisoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 64mg (0.6mmol) of phenethylamine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing a solvent by reduced pressure distillation, and performing column chromatography to obtain a product, wherein the yield is 89%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.89(d,J＝7.5Hz,1H),7.52-7.44(m,2H),7.39-7.27(m,6H),4.80(s,2H),4.26(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝168.6,141.3,137.0,132.6,131.4,128.8,128.2,128.1,127.7,123.90,122.8,49.5,46.4.

HRMS(ESI)(m/z):calcd for C₁₅H₁₄NO[M+H]⁺:224.1070,found:224.1075.

example 20: synthesis of 2- (furan-2-ylmethyl) isoindol-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 58mg (0.6mmol) of 2-furanmethanamine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate, and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 88%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.86(dt,J＝7.6,1.0Hz,1H),7.51(td,J＝7.5,1.2Hz,1H),7.46-7.39(m,2H),7.36(dd,J＝1.7,1.0Hz,1H),6.35-6.27(m,2H),4.78(s,2H),4.36(s,2H).

¹³C NMR(126MHz,CDCl₃,ppm)δ＝170.6,156.5,140.7,130.8,128.6,128.4,126.4,122.1,114.1,55.5,39.2,31.7.

HRMS(ESI)(m/z):calcd for C₁₃H₁₂NO₂[M+H]⁺:214.0863,found:214.0862.

example 21: synthesis of 2- (pyridin-2-yl) isoindolin-1-one:

a three-necked round-bottomed flask was charged with 75mg (0.50mmol) of o-formylbenzoic acid, 94mg (1mmol) of 2-aminopyridine, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 3 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing a solvent by reduced pressure distillation, and performing column chromatography to obtain a product, wherein the yield is 35%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝8.70(dd,J＝8.7,2.9Hz,1H),8.43(d,J＝4.3Hz,1H),7.96(dd,J＝7.5,2.8Hz,1H),7.79(ddd,J＝10.9,5.7,2.1Hz,1H),7.65(td,J＝7.4,2.8Hz,1H),7.60-7.51(m,2H),7.11(q,J＝3.6Hz,1H),5.15(d,J＝2.8Hz,2H).

¹³C NMR(126MHz,CDCl₃)δ＝168.0,151.9,147.7,141.1,138.0,132.6,128.3,124.2,123.0,119.6,114.2,49.9.

HRMS(ESI)(m/z):calcd for C₁₃H₁₁N₂O[M+H]⁺:211.0866,found:211.0871.

example 22: synthesis of 5-methyl-2-phenylisoindol-1-one:

a three-necked round-bottomed flask was charged with 82mg (0.50mmol) of 4-methyl-2-formylbenzoic acid, 56mg (0.6mmol) of aniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 81%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.90-7.84(m,2H),7.81(d,J＝8.2Hz,1H),7.45-7.40(m,2H),7.31(d,J＝6.6Hz,2H),7.17(t,J＝7.4Hz,1H),4.82(s,2H),2.49(s,3H).

¹³C NMR(126MHz,CDCl₃)δ167.7,142.9,140.5,139.6,130.7,129.5,129.2,124.3,124.0,123.1,119.4,50.6,22.0.

HRMS(ESI)(m/z):calcd for C₁₅H₁₄NO[M+H]⁺:224.1070,found:224.1066.

example 23: synthesis of 5-phenyl-2-phenylisoindol-1-one:

a three-necked round-bottomed flask was charged with 113.5mg (0.50mmol) of 4-phenyl-2-formylbenzoic acid, 69.8mg (0.75mmol) of aniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 4 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 60%.

The characterization data of the product are:

1H NMR(500MHz,Chloroform-d)δ＝8.01(d,J＝7.9Hz,1H),7.94-7.90(m,2H),7.78-7.73(m,2H),7.69-7.65(m,2H),7.54-7.43(m,5H),7.22(td,J＝7.4,1.3Hz,1H),4.95(s,2H).

¹³C NMR(126MHz,CDCl3)δ＝167.4,145.5,140.8,140.3,139.5,132.1,129.9,129.2,129.0,128.2,127.8,127.5,124.5,121.3,119.5,50.8.

HRMS(ESI)(m/z):calcd for C₂₀H₁₆NO[M+H]⁺:286.1226,found:286.1231.

example 24: synthesis of 6-chloro-2-phenylisoindol-1-one:

a three-necked round-bottomed flask was charged with 92.5mg (0.50mmol) of 4-chloro-1-formyl-2-benzoic acid, 93mg (1mmol) of aniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate, and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 10mA for 5 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 85%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.90(d,J＝2.0Hz,1H),7.86-7.83(m,2H),7.57(dd,J＝8.1,2.0Hz,1H),7.47-7.42(m,3H),7.20(td,J＝6.7,6.2,1.1Hz,1H),4.85(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝166.2,139.2,138.2,134.99,134.8,132.3,129.3,124.9,124.3,124.0,119.6,50.5.

HRMS(ESI)(m/z):calcd for C₁₄H₁₁ClNO[M+H]⁺:244.0524,found:244.0531.

example 25: synthesis of 5-bromo-2-phenylisoindol-1-one:

a three-necked round-bottomed flask was charged with 143.5mg (0.50mmol) of 4-bromo-1-formyl-2-benzoic acid, 84mg (0.9mmol) of aniline, 169.5mg (0.5mmol) of tetra-N-butylammonium hydrogensulfate, and 5mL of N, N-dimethylformamide, and electrochemically reacted at room temperature under a current of 8mA for 4 hours using a carbon rod as an anode and a carbon rod as a cathode. After the reaction is finished, adding 20mL of ethyl acetate and 100mL of water for extraction, collecting an organic phase after layering, extracting a water phase for 2 times by using ethyl acetate, wherein the dosage of ethyl acetate is 10mL each time, combining the organic phases, adding anhydrous sodium sulfate for drying, removing the solvent by reduced pressure distillation, and performing column chromatography to obtain the product, wherein the yield is 81%.

The characterization data of the product are:

¹H NMR(500MHz,Chloroform-d)δ＝7.91-7.78(m,3H),7.74-7.65(m,2H),7.46(dd,J＝8.6,7.3Hz,2H),7.23(t,J＝7.4Hz,1H),4.88(s,2H).

¹³C NMR(126MHz,CDCl₃)δ＝166.6,141.8,139.1,132.2,132.0,129.3,126.8,126.1,125.6,124.8,119.5,50.2.

HRMS(ESI)(m/z):calcd for C₁₄H₁₀NOBrNa[M+Na]⁺:288.0019,found:288.0017.

from the above examples 1 to 25, it is known that: the reaction is suitable for substrates which mainly comprise amine compounds and o-formyl benzoic acid compounds, the method has a simple electrolytic system and few byproducts; the electrolyte consumption is little, and the electric conductivity is good, need not very high current can reach the reaction requirement. The reaction is applicable to various types of substrates, and the reaction functional group has good tolerance, so that the application range is wide; the reaction yield is high, and part of the reaction yield reaches more than 85 percent; the raw materials, the solvent and the like used in the reaction are cheap and easy to obtain, the reaction process is fast, and the operation is simple and safe, so that the method has the potential of large-scale production.

In conclusion, the invention provides an electrocatalytic preparation method without an external oxidant, and the N-substituted pyrrolidone derivative is synthesized in one step by using an amine compound and a benzoic acid compound through an electrocatalytic reaction. The method has high yield, does not need to use a metal catalyst and an external oxidant, is green and environment-friendly, and has low price; the electrolysis system and the reaction raw materials used in the reaction have low price, the post-treatment is simple and convenient, and the method is suitable for industrial production; the method has the advantages of mild reaction conditions, simple operation and high yield.

While the embodiments of the present invention have been described in detail with reference to the description, the present invention is not limited to the embodiments, and various changes can be made without departing from the gist of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.