Application of 2-aminoquinoline compound in antiviral drugs

Abstract

The invention belongs to the technical field of medicinal chemistry, and particularly discloses application of 2-aminoquinoline compounds in antiviral drugs. The compound has the structural characteristics as shown in a general formula (I), wherein EWG is an electron withdrawing group and is selected from aryl-substituted sulfonyl or alkyl-substituted sulfonyl; r1 is selected from alkyl or aryl; r2 is selected from alkyl or aryl. In-vitro antiviral activity evaluation shows that the 2-aminoquinoline compound has excellent inhibitory activity on influenza A virus subtype H1N1, and the inhibitory activity is obviously superior to that of a clinical first-line drug ribavirin. Meanwhile, the compound shows a good safety characteristic. The compound can be used as an active ingredient for preparing anti-influenza A virus drugs, and has important application value for developing novel high-efficiency and low-toxicity anti-influenza virus drugs. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of medicinal chemistry, and particularly relates to a 2-aminoquinoline compound, a preparation method thereof, and an application thereof in anti-influenza A virus (IAV) drugs. Background Art

[0002] As a class of nitrogen-containing heterocyclic skeletons with important medicinal value, 2-aminoquinoline compounds occupy an important position in the field of innovative drug research and development due to their unique structural features and extensive biological activities. These compounds not only widely exist in natural products, but also become the key targeted structures in medicinal chemistry research due to their significant pharmacological activities such as antibacterial, anti-tumor, and anti-parasitic. However, existing synthetic techniques (such as amination of 2-chloroquinoline, amination of quinoline N-oxide, cyclization reaction of aniline and isocyanate, etc.) generally have technical bottlenecks such as high raw material costs, harsh reaction conditions, and limited functional group tolerance, seriously restricting the efficient construction of structurally diverse 2-aminoquinoline derivatives.

[0003] Although the development of alkynylamide chemistry in recent years has provided a new technical route for the synthesis of 2-aminoquinoline, existing catalytic systems (such as cyclization reactions catalyzed by precious metals) still face many challenges: limited substrate scope (mainly applicable to aryl-terminal alkynylamides), reliance on high-cost transition metal catalysts, and the need for harsh high-temperature reaction conditions, etc. In response to these key technical problems, the applicant's team developed a [4+2] cycloaddition reaction catalyzed by trimethylsilyl trifluoromethanesulfonate (TMSOTf) (Org. Lett., 2024, 26, 3503-3508). This synthetic method has significant advantages: mild reaction conditions, wide substrate scope (compatible with aryl and alkyl-terminal alkynylamides), and high product yields (good to excellent), providing a good solution for the efficient construction of 2-aminoquinoline derivatives.

[0004] On this basis, the applicant further expanded the research on the biological activities of 2-aminoquinoline compounds and found that they have significant anti-influenza A virus (IAV) activity and excellent cell safety, showing great potential to become a new generation of anti-influenza virus lead compounds, and there is no relevant literature report at present. Summary of the Invention

[0005] Based on the efficient synthesis technology of 2-aminoquinoline compounds developed by the applicant in the early stage, through systematic structure-activity relationship research, the present invention found that 2-aminoquinoline derivatives with specific electronic effects and spatial configurations show significant inhibitory activity against influenza A virus (IAV). Particularly noteworthy is that on the premise of maintaining excellent cell safety, the antiviral activity index of the representative compounds of the present invention is significantly better than that of the clinical control drug ribavirin, providing candidate molecules for the development of new anti-influenza A virus drugs.

[0006] For this reason, the object of the present invention is to provide the application of 2-aminoquinoline compounds in anti-influenza A virus (IAV).

[0007] To achieve the object of the present invention, the specific technical solutions are as follows:

[0008] The general structural formula of the 2-aminoquinoline compound is:

[0009]

[0010] Among them, EWG is an electron-withdrawing group, selected from sulfonyl group, aryl-substituted sulfonyl group or alkyl-substituted sulfonyl group; R 1 is a substituent, selected from alkyl group or aryl group; R 2 is a substituent, selected from alkyl group or aryl group.

[0011] Preferably: EWG is selected from sulfonyl group, aryl-substituted sulfonyl group or C1-3 alkyl-substituted sulfonyl group, and the aryl group is preferably a phenyl group substituted by methyl, halogen, nitro or methoxy group; R 1 is selected from benzyl group, C1-3 alkyl group or phenyl group; R 2 is selected from C1-6 alkyl group, phenyl group or thiophenyl group.

[0012] The synthesis route of the 2-aminoquinoline compound is as follows:

[0013]

[0014] The specific synthesis steps are as follows:

[0015] Place 2-aminoaryl ethynyl ketone 1 and alkynyl amide 2 in a dry reaction tube. After replacing with nitrogen, successively add 1,4-dioxane and trimethylsilyl trifluoromethanesulfonate, seal the reaction tube, and stir at the corresponding temperature; monitor the reaction process by thin-layer chromatography. After the reaction is completed, filter by suction and distill off the solvent under reduced pressure. The obtained crude product is separated by column chromatography to obtain 2-aminoquinoline compound 3.

[0016] In the above steps, the molar ratio of 2-aminoaryl ethynyl ketone 1, alkynyl amide 2, and trimethylsilyl trifluoromethanesulfonate is 1:1.2:0.2.

[0017] Furthermore, in the above technical solution, the synthesis route of the raw material 2-aminoaryl ethynyl ketone 1 is as follows:

[0018]

[0019] The specific synthesis steps are as follows:

[0020] 1) Add 2-iodoaniline 4, ethynyltrimethylsilane 5, palladium(II) dichloride bis(triphenylphosphine), copper(I) iodide, and triethylamine into a round-bottom flask. The reaction mixture is stirred at room temperature, and the reaction progress is monitored by thin-layer chromatography. After the reaction is completed, the reaction solution is filtered through a short silica gel column and concentrated under vacuum to obtain a mixture.

[0021] 2) Add the above mixture, potassium carbonate, and methanol into a round-bottom flask. The reaction mixture is stirred at room temperature, and the reaction progress is monitored by thin-layer chromatography. After the reaction is completed, water is slowly added. The resulting mixture is extracted with ethyl acetate, the organic phases are combined, dried over anhydrous sodium sulfate, filtered, concentrated under vacuum, and then purified by flash silica gel column chromatography to obtain 2-ethynylaniline 6.

[0022] 3) Add 2-ethynylaniline 6, benzoyl chloride, palladium(II) dichloride bis(triphenylphosphine), copper(I) iodide, triethylamine, and toluene into a round-bottom flask. The reaction mixture is stirred at room temperature, and the reaction progress is monitored by thin-layer chromatography. After the reaction is completed, water is slowly added. The resulting mixture is extracted with ethyl acetate, the organic phases are combined, dried over anhydrous sodium sulfate, filtered, concentrated under vacuum, and then purified by flash silica gel column chromatography to finally obtain the target product β-(2-aminoaryl)-α,β-alkynone 1.

[0023] In the above steps, the molar ratio of 2-iodoaniline 4, ethynyltrimethylsilane 5, palladium(II) dichloride bis(triphenylphosphine), copper(I) iodide, and potassium carbonate (20.0 mmol) is 1:1.5:0.02:0.04:2; the molar ratio of 2-ethynylaniline 6, benzoyl chloride, palladium(II) dichloride bis(triphenylphosphine), and copper(I) iodide is 1:1.2:0.05:0.05.

[0024] Further studies have shown that the 2-aminoquinoline compounds synthesized in the present invention, as confirmed by in vitro cell activity experiments, not only exhibit significant inhibitory activity against influenza A virus, but also have low cytotoxicity, excellent selectivity index, and show good potential for drug development, and can be used as candidate compounds for anti-influenza A virus drugs. Compared with existing anti-influenza A virus drugs, the 2-aminoquinoline compounds synthesized in the present invention exhibit outstanding comprehensive advantages: First, their antiviral activity is significantly better than the clinically commonly used drug ribavirin; second, detection by the MTT method shows their low cytotoxicity and excellent safety characteristics. These characteristics have led to breakthrough progress in the therapeutic index and clinical applicability of this series of compounds, providing valuable candidate molecules for the development of new, highly effective, and low-toxic anti-influenza A virus drugs. Detailed implementation mode

[0025] To make the technical solution of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments. It should be particularly noted that the following embodiments are only used to illustrate the technical solution of the present invention and do not constitute any limitation to the protection scope of the present invention. Unless otherwise specified, the experimental methods involved in the embodiments are all conventional technical means in the art.

[0026] Main Instruments and Chemical Reagents

[0027] The main instruments used in the experiment include: Bruker Ascend TM 400-type nuclear magnetic resonance spectrometer, Bruker micrOTOF-Q II high-resolution mass spectrometer, Zhiwei Smart Fourier transform infrared spectrometer (Tianjin Gangdong Technology Co., Ltd.), WFH-203B ultraviolet analyzer (Shanghai Huyue Ming Scientific Instrument Co., Ltd.) and XT4A micro melting point detector (Beijing Keyi Dian Guang Instrument Factory).

[0028] The chemical reagents and raw materials used in this experiment (including alkynylamide 2) are all commercially available analytical pure or known compounds. The synthesis method of alkynylamide 2 can refer to relevant literature (Org. Lett. 2016, 18, 5022-5025; Chem. Commun. 2016, 52, 6801-6804; Org. Lett. 2019, 21, 2918-2922; J. Org. Chem., 2024, 89, 1193-1198). Unless otherwise specified, all reactions are carried out under the protection of inert gas (N 2 ) and the solvents are dried by conventional methods. The specific reaction conditions, purification methods and other key parameters involved in the experimental process will be described in detail in the following embodiments to ensure the repeatability of the experimental scheme.

[0029] Example 1: Synthesis of 2-Aminoaryl Ethynyl Ketone 1

[0030]

[0031] 1) Add 2-iodoaniline 4 (10.0 mmol), ethynyltrimethylsilane 5 (15.0 mmol), bis(triphenylphosphine)palladium(II) dichloride (2.0 mol%), copper(I) iodide (4.0 mol%) and triethylamine (30.0 mL) into a 100 mL round-bottom flask. The reaction mixture was stirred at room temperature for 6 hours, and the reaction was monitored by thin-layer chromatography until complete. The reaction solution was filtered through a short silica gel column and concentrated in vacuo to obtain a mixture.

[0032] 2) In another 100 mL round-bottom flask, add the above mixture, potassium carbonate (20.0 mmol), and methanol (40.0 mL). The reaction mixture is stirred at room temperature for 0.5 h, and the reaction is monitored by thin-layer chromatography until complete. Then, water (10.0 mL) is slowly added. The resulting mixture is extracted with ethyl acetate (3 × 10 mL), the organic phases are combined, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and purified by flash silica gel column chromatography (isocratic eluent: petroleum ether / ethyl acetate = 20:1) to obtain 2-ethynylaniline 6.

[0033] 3) In a third 100 mL round-bottom flask, add 2-ethynylaniline 6, benzoyl chloride (12.0 mmol), bis(triphenylphosphine)palladium(II) dichloride (5.0 mol%), copper(I) iodide (5.0 mol%), triethylamine (20.0 mL), and toluene (40.0 mL). The reaction mixture is stirred at room temperature for 6 h. Subsequently, water (10.0 mL) is slowly added. The resulting mixture is extracted with ethyl acetate (3 × 10 mL), the organic phases are combined, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and purified by flash silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 6:1) to finally obtain the target product β-(2-aminoaryl)-α,β-alkynone 1.

[0034]

[0035] 1 H NMR (400 MHz, CDCl 3 ) δ 8.27 - 8.16 (m, 2H), 7.68 - 7.60 (m, 1H), 7.58 - 7.45 (m, 3H), 7.33 - 7.21 (m, 1H), 6.80 - 6.70 (m, 2H), 4.52 (s, 2H). The NMR data is consistent with the literature reports (Eur. J. Org. Chem. 2020, 6805 - 6812).

[0036] Example 2: Synthesis of target compounds 2-aminoquinolines 3a - 3m

[0037] Specifically, in the compound structure: Ts represents p-toluenesulfonyl, Mbs represents p-methoxybenzenesulfonyl, Ms represents methylsulfonyl, and n-hex represents n-hexyl.

[0038]

[0039] Taking the synthesis procedure of compound 3a as an example: β-(2-aminophenyl)-α,β-ynone 1 (44.3 mg, 0.20 mmol), ynamide 2a (86.8 mg, 0.24 mmol), 1,4-dioxane (1.0 mL), and trimethylsilyl trifluoromethanesulfonate (TMSOTf, 7.3 μL, 0.04 mmol) were added to an oven-dried reaction tube, and this operation was completed inside a glove box. After sealing the reaction tube, it was placed in an oil bath at 30 °C and stirred for 3.0 hours. After monitoring the completion of the reaction by thin-layer chromatography, the reaction mixture was cooled to room temperature and filtered through a short silica gel column. The filtrate was concentrated under vacuum and purified by flash silica gel column chromatography (eluent: petroleum ether / dichloromethane / ethyl acetate = 20:4:1) to obtain 2-aminoquinoline derivative 3a (104.9 mg, 0.18 mmol) with a yield of 90%.

[0040] Expansion synthesis: Using the same experimental method, the cyclization reactions of β-(2-aminophenyl)-α,β-ynone 1 prepared in Example 1 and the known compound ynamide 2 synthesized according to the reference literature were respectively carried out to successfully prepare the corresponding target compounds 3b - 3m.

[0041]

[0042] Compound 3a: 90% yield, R f = 0.25 [5:1 petroleum ether:ethyl acetate]; white solid; melting point = 221 - 222 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 8.00 (d, 1H, J = 8.4 Hz), 7.80 (d, 2H, J = 7.2 Hz), 7.72 (t, 1H, J = 7.0 Hz), 7.67 (d, 1H, J = 8.4 Hz), 7.63 (d, 2H, J = 8.3 Hz), 7.58 - 7.52 (m, 2H), 7.42 (t, 2H, J = 7.7 Hz), 7.30 - 7.28 (m, 3H), 7.19 (t, 2H, J = 7.6 Hz), 7.14 (t, 1H, J = 7.4 Hz), 7.05 (t, 2H, J = 7.5 Hz), 6.85 (s, 2H), 6.79 (d, 2H, J = 7.1 Hz), 4.52 (s, 2H), 4.46 (s, 2H), 2.47 (s, 3H); 13 C NMR (100 MHz, CDCl 3)δ196.2, 151.3, 146.5, 143.6, 142.6, 137.0, 136.4, 136.3, 136.1, 135.0, 133.6, 130.5, 129.9, 129.8, 129.5, 129.4, 129.1, 128.8, 128.29, 128.26, 127.9, 127.82, 127.75, 127.7, 127.6, 124.5, 54.6, 40.6, 21.8; IR(KBr)(cm -1 )3062w, 2922w, 1688s, 1597m, 1348s, 1089m; HRMS(ESI): m / z calcd for C 37 H 31 N 2 O 3 S[M + H] + : 583.2050, found 583.2044.

[0043]

[0044] Compound 3b: 82% yield, R f = 0.27 [6:1 petroleum ether:ethyl acetate]; white solid; melting point = 190 - 191 °C; 1 1H NMR(400 MHz, CDCl 3 )δ7.98(d, 1H, J = 8.3 Hz), 7.82(d, 2H, J = 7.6 Hz), 7.73(t, 1H, J = 7.6 Hz), 7.71 - 7.63(m, 3H), 7.58 - 7.52(m, 2H), 7.44 - 7.40(m, 4H), 7.30(t, 1H, J = 7.4 Hz), 7.25 - 7.19(m, 2H), 7.15(t, 1H, J = 7.4 Hz), 7.05(t, 2H, J = 7.5 Hz), 6.92(s, 2H), 6.81(d, 2H, J = 7.4 Hz), 4.48(s, 2H), 4.47(s, 2H); 13 13C NMR(100 MHz, CDCl 3 )δ196.2, 151.1, 146.3, 142.9, 139.2, 138.1, 136.5, 136.3, 135.9, 134.6, 133.7, 130.8, 130.4, 129.75, 129.73, 129.69, 128.9, 128.6, 128.3, 128.2, 128.1, 128.0, 127.83, 127.82, 127.7, 124.5, 54.8, 40.6; IR(KBr)(cm -1)3062w,2924w,1685m,1495m,1344s,1161s; HRMS(ESI): m / z calcd for C 36 H 28 ClN 2 O 3 S[M + H] + : 603.1504, found 603.1500.

[0045]

[0046] Compound 3c: 71% yield, R f = 0.33 [4:1 petroleum ether:ethyl acetate]; white solid; melting point = 250 - 251 °C; 1 H NMR(400 MHz, CDCl 3 ) δ 8.25 (d, 2H, J = 8.8 Hz), 7.95 - 7.92 (m, 3H), 7.86 (d, 2H, J = 7.4 Hz), 7.76 (t, 1H, J = 7.6 Hz), 7.70 (d, 1H, J = 8.2 Hz), 7.62 - 7.56 (m, 2H), 7.46 (t, 2H, J = 7.7 Hz), 7.37 - 7.34 (m, 1H), 7.29 (t, 2H, J = 7.5 Hz), 7.15 (t, 1H, J = 7.4 Hz), 7.05 (t, 4H, J = 7.5 Hz), 6.86 (d, 2H, J = 7.4 Hz), 4.53 (s, 2H), 4.43 (s, 2H); 13 C NMR(100 MHz, CDCl 3 ) δ 196.2, 151.1, 149.9, 146.3, 145.9, 143.4, 136.3, 135.9, 135.6, 134.3, 133.8, 130.5, 130.3, 130.0, 129.7, 129.6, 129.0, 128.44, 128.40, 128.3, 128.22, 128.16, 128.1, 127.8, 124.6, 123.4, 55.0, 40.7; IR(KBr)(cm -1 ) 3067w, 2921w, 2851w, 1686s, 1162s, 1087m; HRMS(ESI): m / z calcd for C 36 H 28 N 3 O 5 S[M + H] + : 614.1744, found 614.1740.

[0047]

[0048] Compound 3d: 71% yield, R f = 0.29 [6:1 petroleum ether: ethyl acetate]; white solid; melting point = 191 - 193 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 8.02 (d, J = 8.4 Hz, 1H), 7.83 - 7.78 (m, 2H), 7.74 - 7.64 (m, 4H), 7.58 - 7.49 (m, 2H), 7.41 (t, J = 7.7 Hz, 2H), 7.28 (t, J = 7.4 Hz, 1H), 7.17 (dt, J = 23.8, 7.4 Hz, 3H), 7.05 (t, J = 7.5 Hz, 2H), 6.96 - 6.76 (m, 6H), 4.51 (s, 2H), 4.46 (s, 2H), 3.90 (s, 3H); 13 C NMR (100 MHz, CDCl 3 ) δ 196.0, 162.9, 151.2, 146.2, 142.4, 136.7, 136.1, 135.9, 134.8, 133.4, 131.3, 130.8, 130.3, 129.7, 129.6, 129.3, 128.6, 128.1, 128.0, 127.7, 127.6, 127.5, 127.5, 127.4, 124.3, 113.4, 55.6, 54.3, 40.4; IR (KBr) (cm -1 ) 3061w, 2920w, 2842w, 1683m, 1362m, 1151s; HRMS (ESI): m / z calcd for C 37 H 31 N 2 O 4 S [M + H] + : 599.1999, found 599.1995.

[0049]

[0050] Compound 3e: 94% yield, R f = 0.25 [6:1 petroleum ether: ethyl acetate]; white solid; melting point = 206 - 207 °C; 1 H NMR (400 MHz, CDCl 3)δ 7.93 - 7.85 (m, 5H), 7.69 - 7.65 (m, 2H), 7.58 (t, 1H, J = 7.4 Hz), 7.52 - 7.50 (m, 1H), 7.48 - 7.37 (m, 7H), 7.33 (d, 2H, J = 8.1 Hz), 4.60 (s, 2H), 2.82 (s, 3H), 2.46 (s, 3H); 13 C NMR (100 MHz, CDCl 3 )δ 196.4, 152.6, 146.4, 143.4, 142.7, 136.28, 136.26, 136.23, 135.1, 133.8, 130.1, 129.7, 129.5, 129.3, 129.1, 128.9, 128.5, 128.3, 128.2, 127.7, 127.6, 124.3, 40.5, 37.3, 21.8.

[0051]

[0052] Compound 3f: 66% yield, R f = 0.31 [4:1 petroleum ether:ethyl acetate]; white solid; melting point = 248 - 249 °C; 1 H NMR (400 MHz, CDCl 3 )δ 7.99 (d, 1H, J = 8.3 Hz), 7.85 - 7.83 (m, 2H), 7.75 (d, 2H, J = 8.3 Hz), 7.71 (t, 1H, J = 7.6 Hz), 7.64 (d, 1H, J = 8.3 Hz), 7.57 (t, 1H, J = 7.4 Hz), 7.50 (t, 1H, J = 8.2 Hz), 7.42 (t, 2H, J = 7.8 Hz), 7.28 - 7.21 (m, 5H), 7.07 - 7.04 (m, 3H), 6.96 (t, 2H, J = 7.7 Hz), 6.71 - 6.68 (m, 2H), 4.50 (s, 2H), 2.46 (s, 3H). 13 C NMR (100 MHz, CDCl 3 )δ 196.3, 152.5, 146.2, 143.3, 142.6, 139.2, 137.3, 136.2, 135.9, 134.6, 133.8, 130.1, 129.7, 129.6, 129.5, 128.9, 128.7, 128.33, 128.30, 127.8, 127.45, 127.38, 127.2, 124.4, 40.4, 21.9, where there are two overlapping carbon signals at 128.9 ppm and 128.33 ppm; IR (KBr) (cm -1)3064w,2921w,1683s,1494m,1343s,1047m; HRMS(ESI): m / z calcd for C 36 H 29 N 2 O 3 S[M + H] + : 569.1893, found 569.1890.

[0053]

[0054] Compound 3g: 86% yield, R f = 0.28 [6:1 petroleum ether: ethyl acetate]; white solid; melting point = 186 - 187 °C; 1 H NMR(400 MHz, CDCl 3 ) δ 8.05 (d, 2H, J = 7.4 Hz), 7.80 (d, 1H, J = 8.3 Hz), 7.68 - 7.58 (m, 5H), 7.54 - 7.50 (m, 2H), 7.49 - 7.45 (m, 1H), 7.30 (d, 2H, J = 8.1 Hz), 7.20 - 7.14 (m, 5H), 4.78 (br, 2H), 4.73 (s, 2H), 2.48 (s, 3H), 2.30 (s, 3H); 13 C NMR(100 MHz, CDCl 3 ) δ 195.1, 152.4, 145.5, 143.8, 141.4, 136.6, 135.7, 135.3, 133.8, 132.3, 129.6, 129.41, 129.37, 129.1, 129.0, 128.6, 128.45, 128.36, 127.8, 127.4, 123.5, 54.4, 39.4, 21.9, 16.0, where there is a carbon signal overlap at 127.8 ppm; IR(KBr)(cm -1 ) 2928w, 1689m, 1353m, 1165s, 1090m, 762m; HRMS(ESI): m / z calcd for C 32 H 29 N 2 O 3 S[M + H] + : 521.1893, found 521.1888.

[0055]

[0056] Compound 3h: 93% yield, R f= 0.36 [6:1 petroleum ether:ethyl acetate]; white solid; melting point = 199 - 200 °C; 1 H NMR(400MHz,CDCl 3 )δ8.06 - 8.04(m,2H),7.79(d,1H,J = 8.4Hz),7.70 - 7.60(m,5H),7.54 - 7.47(m,5H),7.19 - 7.15(m,5H),4.81(br,2H),4.74(s,2H),2.26(s,3H); 13 C NMR(100MHz,CDCl 3 )δ195.0,152.1,145.5,141.7,139.5,136.8,136.5,135.2,133.8,132.2,130.5,129.6,129.5,129.1,129.0,128.8,128.5,128.4,128.0,127.9,127.7,123.5,54.8,39.3,15.8; IR(KBr)(cm -1 )3094w,2930w,1689s,1497m,1355s,1167s; HRMS(ESI):m / z calcdfor C 31 H 26 ClN 2 O 3 S[M + H] + :541.1347,found 541.1342.

[0057]

[0058] Compound 3i: 98% yield, R f = 0.24 [4:1 petroleum ether:ethyl acetate]; white solid; melting point = 193 - 194 °C; 1 H NMR(400MHz,CDCl 3 )δ8.06 - 8.04(m,2H),7.81(d,1H,J = 8.4Hz),7.69 - 7.65(m,3H),7.63 - 7.57(m,2H),7.52(t,2H,J = 7.7Hz),7.47(t,1H,J = 7.0Hz),7.21 - 7.14(m,5H),6.99 - 6.95(m,2H),4.78(br,2H),4.74(s,2H),3.91(s,3H),2.31(s,3H); 13 C NMR(100MHz,CDCl 3) δ 195.1, 163.2, 152.6, 145.5, 141.4, 136.6, 135.7, 133.8, 132.3, 131.1, 130.0, 129.7, 129.4, 129.0, 128.6, 128.44, 128.36, 127.83, 127.82, 127.4, 123.5, 113.9, 55.8, 54.4, 39.4, 16.0; IR(KBr)(cm -1 ) 3061w, 2920w, 2842w, 1683m, 1362m, 1151s; HRMS(ESI): m / z calcd for C 32 H 29 N 2 O 4 S [M + H] + : 537.1843, found 537.1838.

[0059]

[0060] Compound 3j: 71% yield, R f = 0.26 [10:1 petroleum ether: ethyl acetate]; white solid; melting point = 141 - 142 °C; 1 1H NMR(400 MHz, CDCl 3 ) δ 8.06 (d, 2H, J = 7.3 Hz), 7.77 (d, 1H, J = 8.3 Hz), 7.63 - 7.58 (m, 5H), 7.51 (t, 2H, J = 7.6 Hz), 7.45 (t, 1H, J = 8.2 Hz), 7.28 (d, 2H, J = 8.1 Hz), 7.21 - 7.14 (m, 5H), 4.88 (br, 1H), 4.74 (s, 2H), 4.67 (br, 1H), 3.10 (br, 1H), 2.64 (br, 1H), 2.47 (s, 3H), 1.17 - 0.97 (m, 7H), 0.78 (t, 3H, J = 7.3 Hz), 0.33 (br, 1H); 13 13C NMR(100 MHz, CDCl 3 ) δ 195.8, 152.3, 145.4, 143.8, 141.3, 136.7, 136.6, 136.0, 135.0, 133.8, 129.9, 129.5, 129.31, 129.26, 129.0, 128.6, 128.5, 128.4, 128.3, 127.9, 127.4, 123.9, 54.6, 39.4, 31.4, 30.0, 29.9, 29.5, 22.7, 21.8, 14.2; IR(KBr)(cm-1 ) 3063w, 2950m, 2852w, 1693s, 1343s, 1153s; HRMS(ESI): m / z calcd for C 37 H 39 N 2 O 3 S[M + H] + : 591.2676, found 591.2671.

[0061]

[0062] Compound 3k: 79% yield, R f = 0.28 [4:1 petroleum ether:ethyl acetate]; white solid; melting point = 224 - 225 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 7.93 (d, 1H, J = 8.3 Hz), 7.90 - 7.88 (m, 2H), 7.74 - 7.67 (m, 4H), 7.61 - 7.52 (m, 2H), 7.46 (t, 2H, J = 7.7 Hz), 7.34 (dd, 1H, J = 5.1, 1.2 Hz), 7.30 (d, 2H, J = 8.1 Hz), 7.12 - 7.01 (m, 3H), 6.90 - 6.84 (m, 3H), 6.57 (s, 1H), 4.61 (s, 2H), 4.56 (s, 2H), 2.49 (s, 3H); 13 C NMR (100 MHz, CDCl 3 ) δ 196.1, 151.9, 146.5, 144.7, 143.6, 136.3, 136.2, 135.8, 135.1, 133.7, 130.4, 130.3, 129.9, 129.8, 129.5, 129.2, 128.9, 128.4, 128.3, 128.0, 127.7, 127.6, 127.4, 126.7, 124.7, 54.7, 41.0, 21.9, where there is a carbon signal overlap at 129.5 ppm; IR (KBr) (cm -1 ) 3064w, 2933w, 1689s, 1494m, 1344s, 990m; HRMS(ESI): m / z calcd for C 35 H 29 N 2 O 3 S 2 [M + H] + : 589.1614, found 589.1608.

[0063]

[0064] Compound 3l: 96% yield, R f = 0.28 [6:1 petroleum ether: ethyl acetate]; white solid; melting point = 154 - 155 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 8.07 (d, 1H, J = 8.3 Hz), 7.90 (d, 2H, J = 7.4 Hz), 7.72 (t, 1H, J = 7.6 Hz), 7.67 (d, 1H, J = 8.3 Hz), 7.60 (t, 1H, J = 7.4 Hz), 7.53 (t, 1H, J = 7.6 Hz), 7.46 (t, 2H, J = 7.7 Hz), 7.33 - 7.27 (m, 3H), 7.23 - 7.17 (m, 5H), 7.05 (d, 2H, J = 6.7 Hz), 4.54 (s, 2H), 4.44 (s, 2H), 3.09 (s, 3H); 13 C NMR (100 MHz, CDCl 3 ) δ 196.5, 152.0, 146.3, 143.0, 136.2, 135.8, 135.2, 134.9, 133.8, 130.3, 130.0, 129.69, 129.66, 129.0, 128.6, 128.4, 128.3, 128.1, 128.0, 127.8, 127.6, 124.4, 54.5, 41.6, 40.8; IR (KBr) (cm -1 ) 3060w, 2924w, 1671m, 1449m, 1338s, 1147s; HRMS (ESI): m / z calcd for C 31 H 27 N 2 O 3 S [M + H] + : 507.1737, found 507.1733.

[0065]

[0066] Compound 3m: 68% yield, R f = 0.17 [6:1 petroleum ether: ethyl acetate]; white solid; melting point = 137 - 138 °C; 1 H NMR (400 MHz, CDCl 3) δ 8.07 - 8.02 (m, 3H), 7.68 - 7.62 (m, 3H), 7.55 - 7.50 (m, 3H), 7.23 - 7.20 (m, 5H), 4.98 (s, 2H), 4.74 (s, 2H), 3.16 (s, 3H), 2.76 (br, 1H), 2.59 (br, 1H), 1.20 - 0.89 (m, 7H), 0.76 (t, 3H, J = 7.2 Hz), 0.46 (br, 1H); 13 C NMR (100 MHz, CDCl 3 ) δ 195.5, 152.6, 145.7, 142.0, 136.5, 136.2, 135.7, 133.9, 130.0, 129.7, 129.1, 128.9, 128.6, 128.5, 128.3, 128.2, 127.6, 124.0, 55.4, 39.1, 37.4, 31.4, 30.0, 29.8, 29.1, 22.7, 14.2; IR (KBr) (cm -1 ) 3066 w, 2949 m, 2925 m, 1689 s, 1337 s, 1150 s; HRMS (ESI): m / z calcd for C 31 H 35 N 2 O 3 S [M + H] + : 515.2363, found 515.2361.

[0067] Example 3: Study on the antiviral activity of the 2 - aminoquinoline compounds synthesized in Example 2 of the present invention

[0068] The experimental reagents, experimental instruments and their sources used in the study of the antiviral activity of compounds 3a - 3m are shown in Tables 1 and 2.

[0069] Table 1 Experimental reagents and manufacturers

[0070]

[0071] Table 2 Experimental instruments and manufacturers

[0072]

[0073] Detection of the cytotoxicity and antiviral activity of compounds 3a - 3m

[0074] The MDCK cells in good growth state were seeded at 1.4×10 4Cells in good growth condition were inoculated into a 96-well cell culture plate at a density of 1.4×10 cells / well. After adherent growth for 24 h, the old culture medium was discarded, and the cells were gently washed 3 times with pre-cooled PBS buffer. The compound to be tested was prepared into a 20 mM stock solution with DMSO. Serial two-fold dilutions were performed using the virus maintenance medium (from 800 μM to 6.25 μM, a total of 8 gradients). 200 μL of the compound solution at the corresponding concentration was added to each well. At the same time, blank control replicates were set up, with 200 μL of the virus maintenance medium added to each well. Six replicates were set for each concentration. After treatment for 72 h, 20 μL of MTT working solution was added to each well, and the plate was incubated at 37 °C in the dark for 4 h, during which purple formazan crystals were formed. After the incubation, the original solution was discarded, and the supernatant was carefully aspirated. 160 μL of DMSO was added. The plate was shaken on a horizontal shaker for 15 min to fully dissolve the formazan crystals. The OD 492nm value was measured using a microplate reader. The cell survival rate was calculated as (OD of the experimental group / OD of the control group) × 100%. Nonlinear regression analysis was performed using IBM SPSS 27 software to calculate the half cytotoxic concentration (CC 50 ) of the compound. The results are shown in Table 3.

[0075] MDCK cells in good growth condition were inoculated into a 96-well cell culture plate at a density of 1.4×10 4 cells / well. After adherent growth for 24 h, the old culture medium was discarded, and the cells were washed 3 times with PBS. The cells were infected with an A / Weiss / 43 (H1N1) virus suspension at 100 TCID50, with 100 μL added to each well. At the same time, blank control wells were set up, with only 100 μL of virus adsorption solution added. Six replicates were set for each concentration. The treated 96-well plate was placed in an incubator and shaken once every 15 min during incubation at 37 °C (a total of 4 times), and then cultured for 1 h to ensure sufficient virus adsorption. After removing the virus solution, the cells were washed with PBS. The compound was dissolved in DMSO to prepare a 20 mM stock solution, and then serial two-fold dilutions were performed using the virus maintenance medium (from 100 μM to 0.78125 μM, a total of 8 gradients). 200 μL of the corresponding diluted sample was added to each well. At the same time, virus and blank control replicates were set up, with only 200 μL of virus maintenance medium added. Six replicates were set for each concentration. After culturing for 72 h, the OD 492nm value was measured according to the MTT method. The virus inhibition rate was calculated as [(OD of the experimental group - OD of the virus control group) / (OD of the normal group - OD of the virus control group)] × 100%. The half effective concentration (EC 50 ) of the compound was calculated using IBM SPSS 27 software, and the therapeutic index was calculated according to the formula SI = CC 50 / EC 50 . The specific results are shown in Table 3.

[0076] Table 3 Detection results of the cytotoxicity and antiviral activity of compounds 3a - 3m

[0077]

[0078] Note: a Indicates the 50% cytotoxic concentration against MDCK cells, b Indicates the 50% effective concentration against H1N1, c Indicates the therapeutic index SI, d Indicates no anti-IAV activity between 0.625 μM and 100 μM.

[0079] In this invention, through a standardized in vitro antiviral evaluation system, the anti-influenza A virus activity and cytotoxicity of 2-aminoquinoline compounds 3a - 3m were systematically evaluated. Specifically, using the MDCK cell model combined with the MTT method, the clinical epidemic strain A / Weiss / 43(H1N1) was used as the test strain for the experiment. The results showed that compounds 3d (EC 50 = 2.50 ± 0.58 μM) and 3k (EC 50 = 46.91 ± 3.26 μM) both showed significant antiviral activities. Notably, the half-effective concentration of the lead compound 3d was significantly lower than that of the positive control drug ribavirin (EC 50 = 5.28 ± 1.22 μM), and its antiviral activity was increased by 2.1 times. In terms of safety evaluation, 3d showed excellent biocompatibility (CC50 > 290 μM), and its therapeutic index (SI > 116.00) far exceeded the clinical standard (SI > 10), indicating that this compound has a significant therapeutic window advantage. These data fully prove that compound 3d has both high antiviral activity and excellent safety characteristics, and is a promising candidate drug molecule. Based on the above research results, this series of 2-aminoquinoline compounds show important application value in the research and development of new anti-IAV drugs.

Claims

1. The pharmaceutical application of 2-aminoquinoline compounds with the following general structural formula, characterized in that: It is used as an active ingredient in the preparation of anti-influenza A virus drugs: EWG is selected from sulfonyl, aryl-substituted sulfonyl or C1-3 alkyl-substituted sulfonyl, wherein the aryl is selected from phenyl substituted by methyl, halogen, nitro or methoxy; R 1 Selected from benzyl, C1-3 alkyl or phenyl; R 2 Selected from C1-6 alkyl, phenyl or thienyl.

2. The pharmaceutical use of the 2-aminoquinoline compound according to claim 1, characterized in that: EWG is selected from p-toluenesulfonyl, p-chlorobenzenesulfonyl, p-nitrobenzenesulfonyl, p-methoxybenzenesulfonyl or methylsulfonyl; R 1 is selected from benzyl, methyl or phenyl; R 2 is selected from methyl, n-hexyl, phenyl or thienyl.

3. The pharmaceutical use of the 2-aminoquinoline compound as claimed in claim 2, characterized in that: EWG is selected from p-toluenesulfonyl or p-methoxybenzenesulfonyl; R 1 is selected from benzyl; R 2 is selected from phenyl or thienyl.

4. The pharmaceutical use of the 2-aminoquinoline compound as claimed in claim 3, characterized in that: Selected from the following compounds: 5.2-Aminoquinoline compounds, characterized in that It has the following molecular structure:

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