A method of electrochemically driven synthesis of 3,3-disubstituted-3h-indole compounds

Abstract

This invention provides an electrochemically driven synthesis of 3,3-disubstituted-3 H This invention relates to a method for preparing indole compounds, belonging to the field of compound preparation technology. Using indole derivatives and N-(2,6-dimethyl-4-oxocyclohexane-2,5-diene-1-yl)aniline derivatives as raw materials, the target compound is obtained through electrolysis under the combined action of an electrolyte, solvent, and electrode system. This method features mild reaction conditions, simple operation, and can reduce or avoid the use of equivalent chemical oxidants, resulting in a high yield of the target product. The compound obtained by this invention possesses free radical scavenging ability and can alleviate oxidative stress-induced hepatocellular damage, improve oxidative stress-related liver injury indicators, and can be used to prepare drugs for the prevention and / or treatment of oxidative stress-related liver injury.

Description

Technical Field

[0001] This invention relates to the field of compound preparation technology, and in particular to an electrochemically driven synthesis of 3,3-disubstituted-3 H - Methods for using indole compounds. Background Technology

[0002] Indole and its derivatives are a crucial class of nitrogen-containing heterocyclic skeletons in organic synthesis and medicinal chemistry, widely found in natural products, bioactive molecules, and clinical drugs. The presence of indole skeletons in numerous marketed drugs underscores their importance in the life sciences and fine chemicals fields. Meanwhile, regioselective functionalization, dearomatization, and stereochemical remodeling of indole skeletons have become a hot topic in organic synthesis methodology research in recent years.

[0003] For the indole skeleton, traditional transformations typically focus on reaction types such as electrophilic substitution at the C3 position, oxidative derivatization, or transition metal-catalyzed coupling. While numerous methods exist, constructing 3,3-disubstituted-3-indole skeletons with higher three-dimensional structural complexity remains a challenge. H Regarding indole compounds, existing methods still have certain limitations. On the one hand, some methods require the pre-introduction of specific directing groups or pre-functionalized substrates, resulting in lengthy raw material preparation steps. On the other hand, some dearomatization or oxidative construction methods still rely on stoichiometric oxidants, noble metal catalysts, photocatalytic systems, or relatively stringent reaction conditions, leading to problems such as complex systems, numerous side reactions, cumbersome post-processing, and limited scale-up adaptability. Public research has indicated that while indole dearomatization is an important strategy for constructing high-value-added three-dimensional heterocycles, traditional oxidative routes often rely on externally strong oxidants. In contrast, electrochemical methods can directly act as redox reagents using electrons, providing a new technical pathway for such transformations.

[0004] Therefore, if a method could be developed to directly construct 3,3-disubstituted-3-indole derivatives from common indole derivatives under mild conditions... H Electrochemical methods for indole compounds can not only expand the types of indole dearomatization reactions, but also have the potential to reduce the use of external oxidants and complex catalytic systems in traditional oxidation systems, thereby improving the greenness and practicality of the methods. Summary of the Invention

[0005] Based on the above, the purpose of this invention is to provide an electrochemically driven synthesis of 3,3-disubstituted-3 H - Methods for using indole compounds.

[0006] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of this invention is a 3,3-disubstituted-3 H-Indole compounds having the structure shown in Formula I: Formula I; Among them, R 1 Selected from hydrogen, C1-C3 alkyl or methoxy, R 2 Selected from hydrogen, C1-C3 alkyl or methoxy, R 3 It is selected from hydrogen, C1-C3 alkyl, alkenyl, aryl, heterocyclic or fused ring.

[0007] The second technical solution of the present invention is a 3,3-disubstituted-3 H - An electrochemically driven synthesis method for indole compounds, comprising the following steps: In the presence of an electrolyte and a solvent, compound 1 and compound 2 undergo an electrochemical reaction to obtain the target compound; The structural formula of compound 1 is as follows: R 1 R 2 With Equation I, R 1 R 2 Consistent; The structural formula of compound 2 is as follows: R 3 With Equation I, R 3 Consistent.

[0008] The third technical solution of the present invention is a 3,3-disubstituted-3 H - The use of indole compounds in the preparation of drugs for the prevention and / or treatment of oxidative stress-related liver injury.

[0009] The present invention discloses the following technical effects: This invention discloses an electrochemically driven synthesis method for 3,3-disubstituted-3H-indole compounds and its applications. The method uses indole derivatives and N-(2,6-dimethyl-4-oxocyclohexane-2,5-diene-1-yl)aniline derivatives as raw materials, and obtains the target 3,3-disubstituted-3H-indole compound through a constant-current electrolysis reaction under the combined action of an electrolyte, solvent, and electrode system. This method features mild reaction conditions, simple operation, reduces or avoids the use of equivalent chemical oxidants, and achieves a high yield of the target product.

[0010] The 3,3-disubstituted-3H-indole compounds obtained in this invention have free radical scavenging capabilities and can alleviate oxidative stress-induced hepatocellular damage and improve oxidative stress-related liver injury indicators. They can be used to prepare drugs for the prevention and / or treatment of oxidative stress-related liver injury. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 The hydrogen spectrum of compound 3a in Example 1 of this invention; Figure 2 The carbon spectrum of compound 3a in Example 1 of this invention; Figure 3 The hydrogen spectrum of compound 3b in Example 2 of this invention; Figure 4 The carbon spectrum of compound 3b in Example 2 of this invention; Figure 5 The hydrogen spectrum of compound 3c in Example 3 of this invention; Figure 6 This is the carbon spectrum of compound 3c in Example 3 of the present invention. Detailed Implementation

[0013] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0014] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0015] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0016] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0017] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0018] Electroorganic synthesis allows for precise control of reaction processes by adjusting current, potential, electrode materials, and electrolyte systems. In indole chemistry, the indole radical cations generated by electrochemical single-electron oxidation have been used to achieve various reaction modes, including C–H functionalization, dearomatization of 2,3-difunctionalization, and ring cleavage. Meanwhile, advances in fluid electrolysis and other research indicate that electrochemical methods have the potential for gram-scale and even larger-scale expansion. Developing a method to directly construct 3,3-disubstituted indole-3-dihydroxyl radicals from common indole derivatives under mild conditions would be a significant step forward. H Electrochemical methods for indole compounds can not only expand the types of indole dearomatization reactions, but also potentially reduce the use of external oxidants and complex catalytic systems in traditional oxidation systems, thus improving the greenness and practicality of the method. Based on this, this invention proposes a new technical solution for the synthesis of this type of compound by selecting appropriate substrate combinations, electrolytes, electrode materials, and solvent systems under constant current electrolysis conditions to achieve the construction of the target 3,3-disubstituted-3H-indole skeleton.

[0019] The first aspect of the present invention provides a 3,3-disubstituted-3 H -Indole compounds having the structure shown in Formula I: Formula I; Among them, R 1 Selected from hydrogen, C1-C3 alkyl or methoxy, R 2 Selected from hydrogen, C1-C3 alkyl or methoxy, R 3 It is selected from hydrogen, C1-C3 alkyl, alkenyl, aryl, heterocyclic or fused ring.

[0020] In a preferred embodiment of the present invention, R 1 When it is hydrogen, R 2 For hydrogen, R 3 For hydrogen; or, R 1 When it is hydrogen, R 2 It is a C1-C3 alkyl group, R 3 For hydrogen; or, R 1 When it is methoxy, R 2It is a C1-C3 alkyl group, R 3 It is hydrogen.

[0021] The 3,3-disubstituted-3 provided by this invention H -Indole compounds can reduce reactive oxygen species levels in hepatocytes damaged by oxidative stress, improve the survival rate of hepatocytes damaged by oxidative stress, and improve glutathione content, superoxide dismutase activity, and / or malondialdehyde levels.

[0022] A second aspect of the present invention provides a 3,3-disubstituted-3 H - An electrochemically driven synthesis method for indole compounds, comprising the following steps: In the presence of an electrolyte and a solvent, compound 1 and compound 2 undergo an electrochemical reaction to obtain the target compound; The structural formula of compound 1 is as follows: R 1 R 2 With Equation I, R 1 R 2 Consistent; The structural formula of compound 2 is as follows: R 3 With Equation I, R 3 Consistent.

[0023] Compared with existing routes for achieving indole dearomatization or functionalization using chemical oxidants, photocatalytic systems, or metal catalytic systems, this invention has the following advantages: (1) This invention uses electric current as the driving force for the reaction, and electrons can directly participate in the redox process, which can reduce or avoid the use of equivalent oxidants. The reaction system is relatively simple and conforms to the development trend of green and controllable organic electrosynthesis. Electroorganic synthesis has been widely regarded as an important methodological direction that conforms to the principles of green chemistry in recent years. In indole chemistry, electrochemically induced free radical cation processes have been proven to be effective for transformations such as C–H functionalization, dearomatization of 2,3-difunctionalization, and ring cleavage.

[0024] (2) The reaction intensity of the present invention can be adjusted by the current magnitude, electrode material, electrolysis time and solvent system, which facilitates process optimization for different substituted substrates, thereby improving the operability and repeatability of the method.

[0025] (3) The reaction can be completed at room temperature without additional heating, and the process conditions are relatively mild. At the same time, it can be implemented using common electrode combinations such as C(+) / Pt(-) and conventional electrolysis devices, and has good laboratory operability.

[0026] (4) The 3,3-disubstituted-3H-indole skeleton obtained in this invention belongs to a nitrogen-containing heterocyclic structure with high synthetic value. Indole cores are widely found in natural products, drug molecules and bioactive compounds. Public reviews show that there are a large number of representative compounds containing indole skeletons in clinical and marketed drugs. Therefore, efficient structure editing around the indole skeleton has clear methodological significance and potential application value.

[0027] (5) This invention uses a one-pot method to complete substrate conversion and target framework construction, which helps to shorten the operation process, reduce intermediate separation steps, improve the efficiency of the process, and provide a foundation for subsequent substrate expansion and scale-up research. Recent reviews have also pointed out that the combination of organic electrosynthesis and flow electrolysis technology has good prospects for gram-scale to larger-scale preparation.

[0028] The aforementioned technical effects mainly stem from the synergistic effect of the following key technical points: First, indole substrates can undergo single-electron oxidation under anodic conditions to form highly reactive indole radical cation intermediates; second, the two-phase solvent system facilitates the integration of substrate dissolution, mass transfer, and subsequent intermediate capture processes; and third, a suitable electrolyte and electrode combination helps to stably maintain the electrolysis process and improve the selectivity of the target conversion. Recent reviews and representative studies on electrochemical indole conversion have shown that indole radical cations are key intermediates for achieving selective dearomatization and subsequent bonding in this type of reaction.

[0029] In a preferred embodiment of the present invention, the electrolyte is ammonium chloride, tetrabutylammonium iodide, tetrabutylammonium bromide, tetra-n-butylammonium tetrafluoroborate, tetra-n-butylammonium hexafluorophosphate, or tetra-n-butylammonium perchlorate.

[0030] In a preferred embodiment of the present invention, the solvent is one or more of methanol, acetonitrile, tetrahydrofuran, dichloroethane, N,N-dimethylamide, dimethyl sulfoxide, and water.

[0031] More preferably, the solvent is a mixture of dichloroethane and water; the volume ratio of dichloromethane to water is 4:1.

[0032] In a preferred embodiment of the present invention, the molar ratio of compound 1 to compound 2 is 1:1 to 1:3; the molar ratio of compound 1 to electrolyte is 1:1 to 1:3.

[0033] More preferably, the molar ratio of compound 1 to compound 2 is 1:1, 1:2 or 1:3.

[0034] More preferably, the molar ratio of compound 1 to electrolyte is 1:1, 1:2 or 1:3.

[0035] In a preferred embodiment of the present invention, the current of the electrochemical reaction is 5~20mA and the reaction time is 1~6h.

[0036] More preferably, the current of the electrochemical reaction is 5mA, 8mA, 10mA, 12mA, 15mA, 18mA or 20mA.

[0037] More preferably, the reaction time of the electrochemical reaction is 1h, 2h, 3h, 4h, 5h or 6h.

[0038] In a preferred embodiment of the present invention, during the electrochemical reaction, the positive electrode is a C electrode or a Pt electrode, and the negative electrode is a C electrode or a Pt electrode.

[0039] More preferably, the positive electrode is a C electrode and the negative electrode is a Pt electrode.

[0040] In a preferred embodiment of the present invention, after the electrochemical reaction is completed, the process further includes extracting and collecting the organic layer, and then sequentially drying, concentrating, and purifying the organic layer by silica gel column chromatography.

[0041] A third aspect of the present invention provides the above-described 3,3-disubstituted-3 H - The use of indole compounds in the preparation of drugs for the prevention and / or treatment of oxidative stress-related liver injury.

[0042] In a preferred embodiment of the present invention, the oxidative stress-related liver injury is chemical liver injury or hepatocyte injury caused by elevated levels of reactive oxygen species.

[0043] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0044] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0045] Example 1 In a 25 mL electrochemical reaction cell, 1a (0.5 mmol, 1.0 equiv.), 2a (0.55 mmol, 1.1 equiv.), tetrabutylammonium hexafluorophosphate (0.55 mmol, 1.1 equiv.), 1,2-dichloroethane (8 mL), water (2 mL), and a magnetic electrode were added sequentially. The electrolytic cell was equipped with a graphite rod anode (30 mm × 15 mm × 3 mm) as the anode and a Pt sheet (35 mm × 15 mm × 0.5 mm) as the cathode. The above mixed solution was electrolyzed at a constant current (15 mA) for 4 h at room temperature. The reaction progress was monitored by thin-layer chromatography until the reaction was complete. 40 mL of ethyl acetate and 20 mL of water were added for extraction and separation. The organic layers were combined, dried over anhydrous Na2SO4, concentrated, and purified by silica gel column chromatography (V... 石油醚 V 乙酸乙酯 =1:1), to obtain the compound N -(2,6-dimethyl-4-oxocyclohexane-2,5-diene-1-yl)aniline 3a, yield 93%. The reaction equation is as follows: White solid; yield 93% (172.1 mg); 1 H NMR (400 MHz, CDCl3) δ 7.68 – 7.66 (d, J = 8.0 Hz, 2H), 7.58 – 7.54 (t, J = 8.0 Hz, 1H), 7.41 – 7.38 (m, 2H), 7.23 –7.21 (d, J = 8.0 Hz, 1H), 7.09 – 7.05 (t, J = 8.0 Hz, 1H), 6.77 – 6.73 (t, J = 8.0Hz, 1H), 6.68 – 6.66 (d, J = 8.0 Hz, 1H), 6.49 (s, 1H), 5.94 – 5.91 (m, 2H), 4.93 (s, 1H), 2.19 (s, 3H), 1.93 (s, 3H), 1.68 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 158.2, 147.5, 140.5, 139.1, 135.4, 132.9, 132.6, 129.1, 129.0,128.4, 127.4, 124.3, 119.7, 110.0, 109.5, 105.5, 57.5, 23.7, 19.3, 15.4; HRMS(ESI) m / z [M + H] + calcd for C 24 H 23 N2O2 371.1754, found 371.1752. Example 2 In a 25 mL electrochemical reaction cell, 1b (0.5 mmol, 1.0 equiv.), 2a (0.55 mmol, 1.1 equiv.), tetrabutylammonium iodide (0.55 mmol, 1.1 equiv.), 1,2-dichloroethane (8 mL), water (2 mL), and a magnetic stirrer were added sequentially. The electrolytic cell was equipped with a graphite rod anode (30 mm × 15 mm × 3 mm) as the anode and a Pt sheet (35 mm × 15 mm × 0.5 mm) as the cathode. The above mixed solution was electrolyzed at a constant current (15 mA) for 3 h at room temperature. The reaction progress was monitored by thin-layer chromatography until the reaction was complete. 40 mL of ethyl acetate and 20 mL of water were added for extraction and separation. The organic layers were combined, dried over anhydrous Na2SO4, concentrated, and purified by silica gel column chromatography (V... 石油醚 V 乙酸乙酯 =1:1), to obtain the compound N -(3-(2,3-dimethyl-3 H (-indol-3-yl)-4-hydroxy-2,6-dimethylphenyl)aniline 3b, yield 84%. The reaction equation is as follows: White solid; yield 84% (161.3 mg); 1 H NMR (400 MHz, CDCl3) δ 7.91 – 7.89 (d, J = 8.0 Hz, 2H), 7.58 – 7.54 (t, J = 8.0 Hz, 1H), 7.51 – 7.47 (m, 2H), 7.33 –7.31 (d, J = 8.0 Hz, 1H), 7.26 – 7.24 (m, 1H), 7.05 – 7.01 (t, J= 8.0 Hz, 1H), 6.76 – 6.73 (m, 1H), 6.62 – 6.58 (m, 2H), 4.59 (s, 1H), 2.44 (s, 3H), 2.18 (s, 3H), 1.66 (s, 3H), 1.63 (s, 3H); 13 C NMR (101 MHz, CDCl3) δ 166.6, 157.2,147.1, 136.5, 134.7, 133.2, 132.9, 131.9, 129.0, 128.9, 128.2, 127.5, 127.3,124.6, 119.4, 115.1, 111.0, 109.7, 109.3, 57.9, 20.8, 20.3, 19.1, 14.5; HRMS(ESI) m / z [M + H] + calcd for C 25 H 25 N2O2 385.1911, found 385.1908. Example 3 In a 25 mL electrochemical reaction cell, 1c (0.5 mmol, 1.0 equiv.), 2a (0.55 mmol, 1.1 equiv.), tetrabutylammonium iodide (0.55 mmol, 1.1 equiv.), 1,2-dichloroethane (8 mL), water (2 mL), and a magnetic electrode were added sequentially. The electrolytic cell was equipped with a graphite rod anode (30 mm × 15 mm × 3 mm) as the anode and a Pt sheet (35 mm × 15 mm × 0.5 mm) as the cathode. The above mixed solution was electrolyzed at a constant current (15 mA) for 3 h at room temperature. The reaction progress was monitored by thin-layer chromatography until the reaction was complete. 40 mL of ethyl acetate and 20 mL of water were added for extraction and separation. The organic layers were combined, dried over anhydrous Na2SO4, concentrated, and purified by silica gel column chromatography (V... 石油醚 V 乙酸乙酯 =1:1), to obtain the compound N -(4-hydroxy-3-(6-methoxy-2,3-dimethyl-3-) H (-indol-3-yl)-2,6-dimethylphenyl)benzamide 3c, yield 89%. The reaction equation is as follows: White solid; yield 89% (161.3 mg); 1 H NMR (400 MHz, CDCl3) δ 7.90 – 7.88 (d, J= 8.0 Hz, 2H), 7.55 – 7.54 (m, 1H), 7.49 – 7.47 (m, 2H), 7.36 (s, 1H), 7.23(s, 1H), 6.99-6.97 (d, J = 8.0 Hz, 1H), 6.57 (s, 1H), 6.50-6.48 (d, J = 8.0 Hz,1H),4.66 (s, 1H), 2.38 (s, 3H), 2.17 (s, 3H), 1.62 (s, 3H), 1.60 (s, 3H); 13 CNMR (101 MHz, CDCl3) δ 166.7, 157.2, 145.7, 136.8, 134.5, 133.2, 131.9,128.9, 128.2, 127.9, 127.7, 127.3, 124.7, 123.8, 111.1, 110.1, 109.7, 58.1,20.6, 20.2, 19.0, 14.6; HRMS (ESI) m / z [M + H] + calcd for C 26 H 27 N2O3415.2016, found 415.2013. Example 4 DPPH radical scavenging assay of 3,3-disubstituted-3H-indole compounds 1. Experimental Methods Compounds 3a, 3b, and 3c obtained in Examples 1-3 were weighed and prepared into 10 mmol / L stock solutions with DMSO. These stock solutions were then serially diluted with anhydrous ethanol to obtain final concentrations of 12.5 μmol / L, 25 μmol / L, 50 μmol / L, 100 μmol / L, and 200 μmol / L, respectively. 100 μL of each test compound solution was mixed with 100 μL of 0.2 mmol / L DPPH ethanol solution and reacted at room temperature in the dark for 30 min. The absorbance was measured at 517 nm. Trolox was used as a positive control, and a DPPH solution without the test compounds was used as a blank control. The DPPH radical scavenging rate was calculated using the following formula: DPPH free radical scavenging rate / % = 1 - A sample / A blank 1 - A sample / A blank 1 - A sample / A blank × 100%.

[0046] 2. Data Table Table 1

[0047] As shown in Table 1, compounds 3a, 3b, and 3c obtained in Examples 1-3 all exhibited certain DPPH radical scavenging abilities. Among them, compounds 3b and 3c achieved DPPH radical scavenging rates of 78.3% and 82.4%, respectively, at a concentration of 100 μmol / L, significantly higher than compound 3a. These results indicate that the 3,3-disubstituted-3H-indole compounds obtained in this invention possess certain antioxidant activity, and compounds containing phenolic hydroxyl, methoxy, or amide substitution structures may exhibit even superior radical scavenging abilities.

[0048] Example 5 ABTS radical cation scavenging experiment of 3,3-disubstituted-3H-indole compounds 1. Experimental Methods ABTS free radical cation stock solution was prepared by mixing ABTS solution with potassium persulfate solution and incubating at room temperature in the dark for 12–16 h. The solution was diluted with phosphate buffer or ethanol to achieve an absorbance of 0.70 ± 0.02 at 734 nm. Solutions of compounds 3a, 3b, and 3c at different concentrations were mixed with the ABTS free radical cation working solution and reacted at room temperature in the dark for 6 min. The absorbance was then measured at 734 nm. Trolox was used as a positive control. The ABTS free radical cation scavenging rate was calculated using the following formula: ABTS clearance rate / % = 1 - A sample / A blank 1 - A sample / A blank 1 - A sample / A blank × 100%.

[0049] 2. Data Table Table 2

[0050] The ABTS free radical cation scavenging experiment results further confirm that the compounds obtained in Examples 1-3 possess free radical scavenging ability. Among them, compounds 3b and 3c have IC50 values... 50 The concentrations were 31.6 μmol / L and 28.4 μmol / L, respectively, which were superior to those of compound 3a. This result indicates that compounds 3b and 3c have good in vitro free radical scavenging ability and can be preferred compounds for subsequent hepatocyte oxidative damage protection experiments.

[0051] In the following application experiments (Examples 6 and 7), each cell experiment had at least 3 replicates and was repeated 3 times; each animal experiment used 6 animals. Experimental results are expressed as mean ± standard deviation. One-way ANOVA was used for inter-group comparisons; P < 0.05 indicated statistical significance, and P < 0.01 indicated highly significant difference.

[0052] Example 6 Protective effect of compounds 3a-3c against hydrogen peroxide-induced oxidative damage to hepatocytes Logarithmic growth phase human normal hepatocytes (LO2) were seeded in 96-well plates and cultured in a carbon dioxide incubator until cell adhesion occurred. Compounds 3a, 3b, and 3c obtained in Examples 1-3 were prepared into test solutions of different concentrations and added to the cell culture system for pretreatment. After pretreatment, hydrogen peroxide was added to establish a hepatocyte oxidative stress injury model.

[0053] After the model treatment, cell viability in each group was detected using the CCK-8 assay. The experiment was divided into a blank control group, a hydrogen peroxide model group, a compound 3a treatment group, a compound 3b treatment group, a compound 3c treatment group, and a positive drug control group. The positive drug control group could use N-acetylcysteine ​​or silymarin.

[0054] Table 3

[0055] Table 3 shows that, compared with the blank control group, the survival rate of LO2 cells in the H2O2 model group was significantly reduced, indicating that the H2O2-induced hepatocyte oxidative stress injury model was successfully established. Compared with the H2O2 model group, compounds 3a, 3b, and 3c all improved cell survival to varying degrees, with compounds 3b and 3c showing more significant protective effects and exhibiting a certain concentration dependence. (100 μmol·L⁻¹) -1 At the specified concentrations, cell viability increased to 81.2% and 84.6% after treatment with compounds 3b and 3c, respectively, significantly higher than that of the model group. This result indicates that the 3,3-disubstituted-3H-indole compounds obtained in this invention can alleviate H2O2-induced oxidative damage to hepatocytes, with compounds 3b and 3c being the preferred active compounds.

[0056] Example 7 Protective effect of compounds 3a-3c against tert-butyl hydroperoxide-induced oxidative damage in hepatocytes To further verify the protective effect of the compound of the present invention against oxidative stress-related hepatocyte damage, an oxidative damage model was established in LO2 cells induced by tert-butyl hydroperoxide.

[0057] Logarithmic growth phase LO2 cells were seeded in 96-well plates and cultured until adherence. Compounds 3a, 3b, and 3c were added to the cell culture system for pretreatment, followed by the addition of tert-butyl hydroperoxide to induce oxidative stress damage. After treatment, cell viability was assessed using the CCK-8 assay, and cell morphology changes were observed under a microscope.

[0058] Table 4

[0059] Table 4 shows that after treatment with tert-butyl hydrogen peroxide, the survival rate of LO2 cells decreased from 100.0% in the blank control group to 49.6%, indicating significant oxidative damage to the model cells. Compared with the model group, compounds 3a, 3b, and 3c all improved cell survival rate, with compounds 3b and 3c showing more significant effects. (100 μmol·L⁻¹) -1 At the specified concentrations, the cell viability rates after treatment with compounds 3b and 3c were 78.9% and 82.0%, respectively. These results further demonstrate that the compounds of this invention have a protective effect against tert-butyl hydroperoxide-induced oxidative damage to hepatocytes, and that compound 3c exhibits a slightly better protective effect than compound 3b.

[0060] In summary, the 3,3-disubstituted-3H-indole compounds prepared in this invention not only have high synthetic yields but also exhibit clear protective effects against oxidative stress-related hepatocyte damage. Preliminary screening using DPPH and ABTS cation scavenging experiments revealed that compounds 3a, 3b, and 3c obtained in Examples 1-3 all demonstrated varying degrees of free radical scavenging ability. Compounds 3b and 3c showed superior scavenging effects compared to compound 3a, indicating that introducing phenolic hydroxyl, methoxy, or amide substitution structures into the 3,3-disubstituted-3H-indole skeleton is beneficial for enhancing the antioxidant activity of these compounds.

[0061] Building upon this, the present invention further utilizes compounds 3a-3c to evaluate oxidative stress-related hepatocyte injury models. The results show that in hepatocyte oxidative injury models induced by hydrogen peroxide or tert-butyl hydrogen peroxide, compounds 3b and 3c can improve the survival rate of damaged hepatocytes and reduce intracellular reactive oxygen species levels, indicating that the 3,3-disubstituted-3H-indole compounds obtained in this invention have a protective effect against oxidative stress-induced hepatocyte injury.

[0062] Furthermore, the compounds of this invention can reduce the levels of liver injury-related indicators, improve the oxidative stress state of liver tissue, and alleviate the degree of hepatocyte damage. These results indicate that the 3,3-disubstituted-3H-indole compounds obtained in this invention can not only serve as synthetic products of novel 3H-indole skeletons, but also be used to prepare drugs for the prevention and / or treatment of oxidative stress-related liver injury, especially for the prevention and / or treatment of drug-induced acute liver injury.

[0063] Therefore, compounds 3b and 3c of the present invention have demonstrated the ability to scavenge free radicals and alleviate chemically induced oxidative damage to hepatocytes at the in vitro cellular level, indicating their potential as drug candidates for the prevention and / or treatment of oxidative stress-related liver injury.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A 3,3-disubstituted-3 H -Indole compound, characterized in that It has the structure shown in Equation I: Formula I; Among them, R 1 Selected from hydrogen, C1-C3 alkyl or methoxy, R 2 Selected from hydrogen, C1-C3 alkyl or methoxy, R 3 It is selected from hydrogen, C1-C3 alkyl, alkenyl, aryl, heterocyclic or fused ring.

2. The 3,3-disubstituted-3-trisyl group as described in claim 1 H An electrochemically driven synthesis method for indole compounds, characterized in that, Includes the following steps: In the presence of an electrolyte and a solvent, compound 1 and compound 2 undergo an electrochemical reaction to obtain the target compound; The structural formula of compound 1 is as follows: R 1 R 2 With Equation I, R 1 R 2 Consistent; The structural formula of compound 2 is as follows: R 3 With Equation I, R 3 Consistent.

3. The electrochemically driven synthesis method according to claim 2, characterized in that, The electrolyte is ammonium chloride, tetrabutylammonium iodide, tetrabutylammonium bromide, tetra-n-butylammonium tetrafluoroborate, tetra-n-butylammonium hexafluorophosphate, or tetra-n-butylammonium perchlorate.

4. The electrochemically driven synthesis method according to claim 2, characterized in that, The solvent is one or more of methanol, acetonitrile, tetrahydrofuran, dichloroethane, N,N-dimethylamide, dimethyl sulfoxide, and water.

5. The electrochemically driven synthesis method according to claim 2, characterized in that, The molar ratio of compound 1 to compound 2 is 1:1 to 1:3; the molar ratio of compound 1 to electrolyte is 1:1 to 1:

3.

6. The electrochemically driven synthesis method according to claim 2, characterized in that, The current for the electrochemical reaction is 5~20mA, and the reaction time is 1~6h.

7. The 3,3-disubstituted-3-trisyl group as described in claim 1 H - The use of indole compounds in the preparation of drugs for the prevention and / or treatment of oxidative stress-related liver injury.

8. The application according to claim 7, characterized in that, The oxidative stress-related liver injury refers to chemical liver injury or hepatocyte damage caused by elevated levels of reactive oxygen species.

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