Method for synthesizing quinoxaline derivative by catalyzing arylamine and diazo compound with acidic functionalized ionic liquid

Abstract

The invention discloses a method for synthesizing quinoxaline derivatives by catalyzing arylamine and a diazo compound through acidic functionalized ionic liquid, and belongs to the technical field of fine organic synthesis. A 2-aryl aniline compound and a diazo compound are placed in the presence of a solvent, an acid and an ionic liquid, subjected to a cascade reaction of wolf rearrangement, nucleophilic addition, oxidation and cyclization at 100-140 DEG C, cooled to the room temperature, extracted with ethyl acetate, dried with anhydrous sodium sulfate and then subjected to reduced pressure distillation to remove the solvent, a mixed crude product is obtained, and the 2-aryl aniline compound is obtained. And separating and purifying the mixture by adopting silica gel column chromatography to obtain the quinoxaline derivative. The method has the advantages that the catalyst is green and renewable, the operation is simple, the selectivity is high, the substrate range is wide, and the tolerance to functional groups is good, the diazo compound is rearranged into the phthalic acid by virtue of tandem wolf rearrangement, nucleophilic addition, oxidation and cyclization, and a new way is provided for synthesis of quinoxaline derivatives.

Description

Technical Field

[0001] This invention belongs to the field of fine organic synthesis technology, specifically relating to a method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using acidic functionalized ionic liquid catalysis. Background Technology

[0002] Quinoxaline derivatives are a class of compounds with quinoxaline (a heterocycle formed by two benzene rings connected by two nitrogen atoms) as the core skeleton. By introducing different substituents (such as alkyl, aryl, halogen, hydroxyl, etc.) on the ring, their structural diversity endows them with a wide range of biological activities and material properties, showing great potential in the fields of medicine, agriculture, and materials.

[0003] Currently, synthetic methods for quinoxaline derivatives include the classic condensation method: condensation of o-phenylenediamine with a 1,2-dicarbonyl compound (such as glyoxal) under acidic conditions to synthesize quinoxaline derivatives; and the reaction of 2-arylaniline with diazo compounds via N–H bond insertion or C–H bond activation. However, these methods suffer from poor substrate compatibility, narrow applicability, susceptibility to carbonyl unit damage, and limited product structure, necessitating the development of novel synthetic methods for quinoxaline derivatives.

[0004] In recent years, the cyclization reaction of 2-arylaniline, which possesses both carbon and nitrogen nucleophilic sites, with acceptor-acceptor type diazo compounds has become an efficient method for constructing structurally complex nitrogen heterocycles and an effective route for constructing structurally complex N-heterocyclic compounds. In this regard, Sun's team reported a catalytically divergent cyclization reaction between 2-indoleaniline and diazo compounds (Dhole, S.; Chiu, W.-J.; et al. Adv. Synth. Catal. 2019, 361, 2916-2925). The reaction is activated by a free amino-assisted C2–H bond, followed by amidation with the diazo compound to form diaza[1,7-a]indole; while when using a Ru(II) catalyst, the reaction undergoes ruthenium-carbene complex formation, NH2 group insertion, and cascade cyclization processes, ultimately generating quinoxaline compounds. In 2021, Nan et al. achieved a tandem process of 2-arylaniline and diazonium carbene via N–H insertion / electrophilic aromatic substitution / selective C–C bond cleavage through a Brønsted acid-promoted [5+1] cyclization reaction (Chen, P.; Nan, J.; et al. Chem. Sci. 2021, 12, 803-811.). This reaction yielded the target product through the cleavage of the carbonyl fragment of the diazonium compound. Currently, there are no reports of strategies combining Wolff rearrangement with C / N cyclization reactions to selectively construct products. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using acidic functionalized ionic liquid catalysis, thereby solving the technical problems of poor substrate compatibility, narrow applicability, easy damage to carbonyl units, and single product structure in existing quinoxaline derivative synthesis methods.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] The first aspect of the present invention discloses a method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid catalyst. The method involves placing a 2-arylaniline compound and a diazo compound in a solvent, an acid, and an ionic liquid, reacting them at 100–140 °C, and then separating and purifying the mixture to obtain the quinoxaline derivatives.

[0008] The structural formula of the 2-arylaniline compounds is as follows: The structural formula of the diazo compound is The structural formula of quinoxaline derivatives is R=H, F, Cl, Br or OBn, R'=H, F, Cl or Br, R 1 =Ph, 4-BrPh, n-C3H7 or Me; R 2 =CO-Ph, CO-Me, CO-Ph-4-Br, CO2Et or Me.

[0009] Preferably, the molar ratio of the 2-arylaniline compound to the diazo compound is 1:1.

[0010] Preferably, the solvent is isopropanol.

[0011] Preferably, the acid is acetic acid.

[0012] Preferably, the ionic liquid is

[0013] Preferably, the reaction time is 12 hours.

[0014] Preferably, silica gel column chromatography is used for separation and purification.

[0015] Preferably, the reaction product is extracted, dried, and solvent removed before separation and purification.

[0016] More preferably, ethyl acetate is used for extraction.

[0017] Preferably, anhydrous sodium sulfate is used for drying.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] This invention provides a method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid catalysis. The method involves a tandem reaction of 2-arylaniline derivatives and diazo compounds in the presence of an ionic liquid, acid, and solvent, involving Wolf rearrangement, nucleophilic addition, oxidation, and cyclization to obtain the quinoxaline derivatives. In this reaction, 1) using the 2-arylaniline derivative as the main reactant, a symmetrical diazo compound is used as another reactant. Under the electrostatic interaction of the acidic ionic liquid, the symmetrical diazo compound undergoes an intramolecular Wolf rearrangement, releasing N2 and forming an enone intermediate. Subsequently, isopropanol undergoes nucleophilic addition to the enone intermediate to obtain another intermediate, which is then hydrolyzed and decarboxylated to generate phenylbenzyl ketone, subsequently oxidized to benzoyl in an oxygen atmosphere. Next, 2-arylaniline undergoes nucleophilic addition to form an imine intermediate, which is then electrophilically added to yield a cyclic amine. Finally, the cyclic amine undergoes hydrolysis to release benzoic acid, generating the final product. On the other hand, using an asymmetric diazo compound as another reactant, the Wolf rearrangement involves the migration of the benzyl group instead of the ethoxy group, resulting in the formation of an enone. The enone is then oxidized to form an α-keto ester. Then, 2-arylaniline selectively undergoes nucleophilic addition to the more reactive ketone site in the α-keto ester, generating an imine. The imine then undergoes electrophilic addition, yielding the product via the dissociation of hydrogen from ethyl carbonate. Under optimized conditions, this method is well-suited for both symmetric and asymmetric diazo compounds, yielding various quinoxaline compounds with excellent selectivity. 2) Using ionic liquids as catalysts offers the advantage of being green and recyclable. Therefore, the reaction mechanism of this method differs from existing methods for preparing quinoxaline derivatives. It exhibits good compatibility with a variety of diazo compounds, especially for asymmetric diazo compounds. Through highly selective Wolf rearrangement and C–C bond cleavage, the carbonyl unit can be specifically retained to generate the target product. It has advantages such as green and recyclable catalyst, simple operation, high selectivity, broad substrate range, and good functional group tolerance, which can meet the needs of medicinal chemistry, materials science and other fields for diverse quinoxaline compounds. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the following descriptions and definitions are only general descriptions of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in the event of any conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] Unless otherwise specified, Me represents “methyl”, Et represents “ethyl”, OBn represents “benzyloxy”, and Ph represents “phenyl”.

[0025] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0026] This invention provides a method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using acidic functionalized ionic liquids, the reaction formula of which is as follows:

[0027]

[0028] 2-Arylaniline compound 1 and diazo compound 2 were subjected to a tandem reaction of Wolf rearrangement, nucleophilic addition, oxidation and cyclization in the presence of solvent, acid and ionic liquid at 100-140 °C. After cooling to room temperature, the mixture was extracted with ethyl acetate and dried with anhydrous sodium sulfate. The solvent was then removed by vacuum distillation to obtain a crude mixture. The mixture was separated and purified by silica gel column chromatography to obtain quinoxaline derivative 3.

[0029] Where R = H, F, Cl, Br or OBn; R' = H, F, Cl or Br; R 1 =Ph, 4-BrPh, n-C3H7 or Me; R 2 =CO-Ph, CO-Me, CO-Ph-4-Br, CO2Et or Me; the molar ratio of aryl aniline compound to diazo compound is 1:1; the solvent includes, but is not limited to, isopropanol; the acid includes, but is not limited to, acetic acid; the ionic liquid is...

[0030] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0031] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" represents a percentage by mass, and "ratio" represents a mass ratio.

[0032] Example 1

[0033]

[0034] At room temperature, 0.20 mmol of 2-arylaniline 1a, 0.20 mmol of 2-diazo-1,3-diphenylpropane-1,3-dione 2a, 0.20 mmol of ionic liquid IL-1 (1-(4-sulfonyl)-butyl-3-methylimidazolium tetra(cerium trifluoromethanesulfonate) salt; 0.3 equiv.), 5 equiv. of acetic acid, and 1.0 mL of isopropanol were accurately weighed sequentially into a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was added to the product, and the mixture was extracted with ethyl acetate and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 6-phenylindodo[1,2-a]quinoxaline 3aa in 92% yield.

[0035] The characterization data of the obtained 6-phenylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.56(t,J=9.1Hz,2H),8.14(dd,J=8.0,1.6Hz,1H),8.12–8.03( m,2H),7.98(d,J=8.0Hz,1H),7.72–7.57(m,5H),7.50(td,J=7.3,3.6Hz,2H),7.30(s,1H)ppm. 13C NMR(101MHz,Chloroform-d)δ156.41,138.41,136.44,133.20,130.70,130.35,130.15,129.34 ,129.27,128.81,128.76,128.49,124.50,124.33,122.94,122.80,114.80,114.73,102.64ppm.

[0036] Example 2

[0037]

[0038] At room temperature, 0.20 mmol of 2-(4-(benzyloxy)-1H-inden-1-yl)aniline 1b, 0.20 mmol of 2-diazo-1,3-diphenylpropane-1,3-dione 2a, 0.3 equiv. of ionic liquid IL-1, 5 equiv. of acetic acid, and 1.0 mL of isopropanol were accurately weighed sequentially into a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying over anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 8-(benzyloxy)-6-phenylindolo[1,2-a]quinoxaline 3ab in 86% yield.

[0039] The characterization data of the obtained 8-(benzyloxy)-6-phenylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.49(d,J=8.4Hz,1H),8.31(d,J=7.9Hz,1H),8.07(d,J=7.3Hz,2H),8.01(d,J=8.8Hz,1H) ,7.68(q,J=6.8Hz,5H),7.55(dd,J=20.8,7.9Hz,4H),7.44(dt,J=11.2,6.6Hz,3H),6.89(d,J=7.8Hz,1H),5.29(s,2H). 13 C NMR(101MHz,Chloroform-d)δ155.58,153.66,136.16,135.09,131.54,129.46,129.16,129.00 ,128.51,128.06,127.82,127.45,126.60,125.06,121.73,114.88,107.23,103.07,70.15ppm.

[0040] Example 3

[0041]

[0042] At room temperature, 2-(4-fluoro-1H-inden-1-yl)aniline 1c (0.20 mmol), 2-diazo-1,3-diphenylpropane-1,3-dione 2a (0.20 mmol), ionic liquid IL-1 (0.3 equiv.), acetic acid (5 equiv.), and isopropanol (1.0 mL) were accurately weighed sequentially into a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying with anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 8-fluoro-6-phenylindodo[1,2-a]quinoxaline 3ca in 70% yield.

[0043] The characterization data of the obtained 8-fluoro-6-phenylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.58(d,J=8.4Hz,1H),8.34(d,J=8.8Hz,1H),8.24(dd,J=8.0, 1.6Hz,1H),8.14–8.04(m,2H),7.82–7.52(m,6H),7.50(s,1H),7.20(dd,J=9.5,7.9Hz,1H). 13 CNMR(101MHz,Chloroform-d)δ158.50,156.35,156.01,137.92,136.37,135.11,130.68,130.39,129.91,129.13,12 8.90,128.75,128.69,125.00,124.93,124.84,119.44,119.21,114.80,110.83,110.79,107.20,107.02,98.47ppm.

[0044] Example 4

[0045]

[0046] At room temperature, 1 d (0.20 mmol) of 2-(5-bromo-1H-inden-1-yl)aniline, 2a (0.20 mmol) of 2-diazo-1,3-diphenylpropane-1,3-dione, 0.3 equiv. of ionic liquid IL-1, 5 equiv. of acetic acid, and 1.0 mL of isopropanol were accurately weighed sequentially in a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying over anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 3 da (9-bromo-6-phenylindolo[1,2-a]quinoxaline) in 75% yield.

[0047] The characterization data of the obtained 9-bromo-6-phenylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.41(d,J=8.3Hz,1H),8.29–8.20(m,2H),8.11(d,J=8.0Hz,1H),8.06–7 .99(m,2H),7.77(d,J=9.0Hz,1H),7.62(dd,J=7.0,3.6Hz,4H),7.49(t,J=7.8Hz,1H),7.15(s,1H)ppm. 13 C NMR(101MHz,Chloroform-d)δ155.82,137.77,136.11,132.29,131.84,131.33,131.25,130.60 ,130.02,129.56,129.31,128.57,128.43,128.40,124.45,116.06,114.44,101.13,86.63ppm.

[0048] Example 5

[0049]

[0050] At room temperature, 0.20 mmol of 4-fluoro-2-(1H-inden-1-yl)aniline 1e, 0.20 mmol of 2-diazo-1,3-diphenylpropane-1,3-dione 2a, 0.3 equiv. of ionic liquid IL-1, 5 equiv. of acetic acid, and 1.0 mL of isopropanol were accurately weighed and added sequentially to a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying over anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 3ea of ​​2-fluoro-6-phenylindodo[1,2-a]quinoxaline, in 83% yield.

[0051] The characterization data of the obtained 2-fluoro-6-phenylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.44(d,J=8.7Hz,1H),8.25(d,J=10.3Hz,1H),8.08(dd,J=23.6,7.3Hz,3H) ,7.98(d,J=8.1Hz,1H),7.65–7.59(m,4H),7.51(t,J=7.5Hz,1H),7.30(s,1H),7.21(t,J=8.4Hz,1H)ppm. 13 C NMR(101MHz,Chloroform-d)δ163.33,138.16,133.07,132.14,132.04,130.94,130.24,129.50 ,128.85,128.70,124.80,123.20,123.05,114.36,111.77,111.54,103.02,102.28,101.99ppm.

[0052] Example 6

[0053]

[0054] At room temperature, 0.20 mmol of 2-arylaniline 1a, 0.20 mmol of 3-diazapentane-2,4-dione 2b, 0.3 equiv. of ionic liquid IL-1, 5 equiv. of acetic acid, and 1.0 mL of isopropanol were accurately weighed sequentially into a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying with anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 6-methylindolo[1,2-a]quinoxaline 3ba in 78% yield.

[0055] The characterization data of the obtained 6-methylindo[1,2-a]quinoxaline are as follows: 1 H NMR (400MHz, Chloroform-d) δ8.50(t,J=8.6Hz,2H),8.00(dd,J=7.9,2.1Hz,2H),7.67–7.55(m,2H),7.48(q,J=7.8Hz,2H),7.21(s,1H),2.86(s,3H)ppm. 13 C NMR(101MHz,Chloroform-d)δ155.45,135.95,133.09,130.43,129.93,129.71,12 9.17,127.95,124.37,124.18,122.83,122.73,114.76,114.72,100.17,22.51ppm.

[0056] Example 7

[0057]

[0058] At room temperature, 2-arylaniline 1a (0.20 mmol), 1,3-bis(4-bromophenyl)-2-diazopropane-1,3-dione 2c (0.20 mmol), ionic liquid IL-1 (0.3 equiv.), acetic acid (5 equiv.), and isopropanol (1.0 mL) were accurately weighed sequentially into a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying over anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 4-bromo-6-phenylindolo[1,2-a]quinoxaline 3ac in 78% yield.

[0059] The characterization data of the obtained 4-bromo-6-phenylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.56(t,J=9.4Hz,2H),8.11(dd,J=7.9,1.5Hz,1H),7.98(t,J =8.3Hz,3H),7.76(d,J=8.1Hz,2H),7.73–7.58(m,2H),7.51(t,J=7.5Hz,2H),7.26(s,1H). 13 C NMR(101MHz,Chloroform-d)δ155.17,137.24,136.27,133.25,132.02,130.71,130.39 ,129.30,128.88,128.77,124.72,124.56,124.47,122.98,114.86,114.75,102.44ppm.

[0060] Example 8:

[0061]

[0062] At room temperature, 2-arylaniline 1a (0.20 mmol), ethyl 12-diazo-3-oxohexanoate 2d (0.20 mmol), ionic liquid IL-1 (0.3 equiv.), acetic acid (5 equiv.), and isopropanol (1.0 mL) were accurately weighed sequentially into a pressure tube. The mixture was stirred at 140 °C for 12 hours under oxygen conditions and then cooled to room temperature. A saturated aqueous solution of sodium bicarbonate was then added to the product, followed by extraction with ethyl acetate and drying over anhydrous sodium sulfate. After solvent removal under reduced pressure, the crude product was purified by silica gel column chromatography, eluting with ethyl acetate-petroleum ether (1 / 50 v / v) to give 6-propylindodo[1,2-a]quinoxaline 3ad in 62% yield.

[0063] The characterization data of the obtained 6-propylindo[1,2-a]quinoxaline are as follows: 1 H NMR(400MHz,Chloroform-d)δ8.49(t,J=8.3Hz,1H),8.00(dd,J=11.7,7.8Hz,1H),7.58(dt,J=15.4,7.9Hz, 1H),7.46(q,J=7.7Hz,1H),7.23(s,0H),3.13(t,J=7.9Hz,1H),2.04(q,J=7.5Hz,1H),1.16(t,J=7.4Hz,1H). 13 C NMR (101 MHz, Chloroform-d)δ

[0064] 158.93,133.00,130.29,129.75,129.62,129.11,128.66,127.80,124.20,124.05,122.69,122.62,114.65,37.92,21.68,14.34ppm.

[0065] The NMR data from Examples 1 to 8 show that the obtained products are consistent with expectations, indicating that quinoxaline derivatives have been successfully synthesized.

[0066] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make improvements and modifications without departing from the core technology of the present invention, and such improvements and modifications should also fall within the patent protection scope of the present invention. Any changes within the meaning and scope equivalent to the claims of the present invention should be considered as included within the scope of the claims.

Claims

1. A method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid catalysis, characterized in that, 2-arylaniline compounds were reacted with diazo compounds in solvents, acids and ionic liquids at 100–140 °C, and then separated and purified to obtain quinoxaline derivatives. The structural formula of the 2-arylaniline compounds is as follows: The structural formula of the diazo compound is The structural formula of quinoxaline derivatives is R=H, F, Cl, Br or OBn, R'=H, F, Cl or Br, R 1 =Ph, 4-BrPh, n-C3H7 or Me; R 2 =CO-Ph, CO-Me, CO-Ph-4-Br, CO2Et or Me.

2. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid catalysis according to claim 1, characterized in that, The molar ratio of 2-arylaniline compounds to diazo compounds is 1:

1.

3. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid according to claim 1, characterized in that, The solvent is isopropanol.

4. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds catalyzed by an acidic functionalized ionic liquid according to claim 1, characterized in that, The acid is acetic acid.

5. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid according to claim 1, characterized in that, The ionic liquid is 6. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid according to claim 1, characterized in that, The reaction time is 12 hours.

7. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid according to claim 1, characterized in that, Separation and purification were performed using silica gel column chromatography.

8. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid according to claim 1, characterized in that, Before separation and purification, the reaction product is extracted, dried and the solvent is removed.

9. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds using an acidic functionalized ionic liquid according to claim 8, characterized in that, Extraction was performed using ethyl acetate.

10. The method for synthesizing quinoxaline derivatives from aromatic amines and diazo compounds catalyzed by an acidic functionalized ionic liquid according to claim 8, characterized in that, Anhydrous sodium sulfate was used for drying.

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