Synthesis of aryl [a] carbazole compound from alpha-haloketone and 2-aryl indole

Abstract

The invention provides a method for preparing an aryl [a] carbazole compound by taking a 2-aryl indole compound and alpha-haloketone as raw materials and reacting under an acidic condition. Compared with other methods for preparing the aryl [a] carbazole compound, the method disclosed by the invention does not need any metal catalyst, the used raw materials and reagents are cheap and easy to obtain, the substrate application range is wide, and the method is suitable for industrial production. Various substituted 2-aryl indole compounds and cyclic or chain alpha-haloketones (or phenyl or naphthyl substituted alpha-haloketones) can smoothly react to prepare a series of aryl [a] carbazole compounds. The method has the advantages of mild reaction conditions, fast reaction speed, good chemical selectivity, few side reactions, realization of gram-scale amplification, convenient subsequent product separation, high reaction yield, realization of industrial production, and substantial economic and social benefits.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pharmaceutical synthesis and chemical product synthesis, and particularly relates to a method for synthesizing aryl [a] carbazole by directly reacting under acidic conditions using an alpha-haloketone and a 2-arylindole compound as raw materials. BACKGROUND

[0002] The wide presence of nitrogen heterocycles in various natural products, organic materials and drugs has always attracted much attention in the field of synthesis. As an important representative of nitrogen-containing polycyclic aromatic compounds, aryl [a] carbazole has excellent biological activity and unique optical properties, and has irreplaceable application value in the fields of medicine and materials. For example, its derivatives can be used as topoisomerase inhibitors in the research and development of anti-tumor drugs, and can be used as charge transport core structural units in organic optoelectronic materials. Therefore, developing an efficient, green and low-cost synthesis process of aryl [a] carbazole is one of the research focuses in the field of organic synthesis. In view of its importance, various effective methods for constructing aryl [a] carbazole skeleton have been developed. The intermolecular [4+2] cycloaddition reaction of 2-arylindole with alkyne, alpha-diazo carbonyl compound, sulfonium ylide, olefin, diaryliodonium salt, benzoquinone, iodonium ylide or maleimide catalyzed by noble metal rhodium or palladium has become one of the most effective methods for preparing aryl [a] carbazole. Although great progress has been made in this field, most of the above methods still have certain limitations, such as expensive catalyst, high reaction temperature, trace amount of transition metal remaining in the product, limited substrate range, etc. In summary, the existing technology has the problems of metal residue, high cost, narrow substrate range, complex product, low yield, etc., and it is urgent to develop a method for synthesizing aryl [a] carbazole from alpha-haloketone and 2-arylindole without metal, with high selectivity and wide substrate range. SUMMARY

[0003] The purpose of the present application is to provide a method for preparing aryl [a] carbazole compounds by reacting 2-arylindole compounds and alpha-haloketones under acidic conditions. The purpose of the present application can be achieved by the following technical solutions: A method for preparing aryl [a] carbazole compounds from 2-arylindole compounds: under acidic conditions, 2-arylindole compounds represented by general formula (I) and alpha-haloketones represented by general formula (II) react in a solvent to obtain aryl [a] carbazole compounds represented by general formula (III), and the chemical reaction formula is as follows: wherein R 1Selected from H, C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkoxy; R 2 Selected from H, C1-C6 alkyl, C1-C6 alkoxy, or nitro groups; R 3 Selected from H, C1-C6 alkyl or C1-C6 alkoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or an alkyl or alkoxy-substituted benzene ring; R 4 Selected from H, C1-C6 alkyl or C1-C6 alkoxy groups; R 5 Selected from hydrogen or C1-C6 alkyl groups; R 6 Selected from C1-C6 alkyl, phenyl, substituted phenyl, or naphthyl groups; R 7 Selected from H, C1-C6 alkyl or C1-C6 alkoxy; or R 6 and R 7 They connect together to form -(CH2). n - where n = 3-6; X is a halogen. Preferably, where R 1 Selected from H, C1-C4 alkyl, C1-C4 alkoxy, or C1-C4 haloalkoxy; R 2 Selected from H, C1-C4 alkyl, C1-C4 alkoxy, or nitro groups; R 3 Selected from H, C1-C4 alkyl or C1-C4 alkoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or a C1-C4 alkyl or C1-C4 alkoxy-substituted benzene ring; R 4 Selected from H, C1-C4 alkyl or C1-C4 alkoxy groups; R 5 Selected from hydrogen or C1-C4 alkyl groups; R 6 Selected from C1-C4 alkyl, phenyl, substituted phenyl, or naphthyl groups, wherein the substituent on the benzene ring of the substituted phenyl group is selected from C1-C4 alkyl, C1-C4 alkoxy, halogen, hydroxy, or nitro groups; R 7 Selected from H, C1-C4 alkyl or C1-C4 alkoxy; or R 6 and R 7 They connect together to form -(CH2). n - where n = 4; X is a halogen. More preferably, where R 1 Selected from H, C1-C2 alkyl, C1-C2 alkoxy, or C1-C2 haloalkoxy; R 2 Selected from H, C1-C2 alkyl, C1-C2 alkoxy, or nitro groups; R 3 Selected from H, C1-C2 alkyl or C1-C2 alkoxy; or R2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or a C1-C2 alkyl or C1-C2 alkoxy-substituted benzene ring; R 4 Selected from H, C1-C2 alkyl or C1-C2 alkoxy groups; R 5 Selected from hydrogen or C1-C2 alkyl groups; R 6 Selected from C1-C2 alkyl, phenyl, substituted phenyl, or naphthyl groups, wherein the substituent on the benzene ring of the substituted phenyl group is selected from C1-C2 alkyl, C1-C2 alkoxy, halogen, hydroxy, or nitro groups; R 7 Selected from H, C1-C2 alkyl or C1-C2 alkoxy; or R 6 and R 7 They connect together to form -(CH2). n - where n = 4; X is chlorine or bromine. Optimally, where R 1 Selected from H, methyl, or trifluoromethoxy; R 2 Selected from H, methyl, methoxy, or nitro; R 3 Selected from H, methyl, ethyl, or methoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or a methoxy-substituted benzene ring; R 4 Selected from H, methyl, or methoxy; R 5 It is hydrogen; R 6 Selected from methyl, phenyl, tolyl, chlorophenyl, methoxyphenyl, hydroxyphenyl, nitrophenyl, or 2-naphthyl; R 7 Selected from H or methyl; or R 6 and R 7 They connect together to form -(CH2). n - where n = 4; X is chlorine or bromine. In the above method for preparing aryl[a]carbazole compounds, preferably, the acidic condition is HCl or TsOH; the solvent is an alcohol solvent or an aromatic solvent; and the reaction temperature is 0-150℃. More preferably, the alcohol solvent is ethanol, and the aromatic solvent is benzene, toluene, xylene, or chlorobenzene; the reaction temperature is 60-150℃; most preferably, when the acidic condition is TsOH, the solvent is toluene; when the acidic condition is HCl, the solvent is ethanol. Optimally, the reaction temperature of the above method for preparing aryl[a]carbazole compounds is 70-120°C; when the acidic conditions are inorganic acid (HCl) and the solvent is ethanol, the specific operation is as follows: add an ethanol solution saturated with hydrogen chloride gas; the molar ratio of the 2-arylindole compound represented by general formula (I) to the α-haloketone represented by general formula (II) is 1:(0.8-1.2). The above method for preparing aryl[a]carbazole compounds comprises the following steps: under acidic conditions, a mixed solution of the solvent, the 2-arylindole compound represented by general formula (I), and the α-haloketone represented by general formula (II) is heated and reacted. After the reaction is completed, the aryl[a]carbazole compound represented by general formula (III) is obtained by separation and purification. The above method for preparing aryl[a]carbazole compounds includes the following separation and purification procedure after the reaction: saturated sodium carbonate solution is added to the reaction mixture, followed by extraction with ethyl acetate and dichloromethane in sequence, the organic phases are combined, dried with anhydrous sodium sulfate, filtered, and the solvent is removed by vacuum distillation. Finally, the aryl[a]carbazole compounds are purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Compared with existing methods for preparing aryl[a]carbazole compounds, the present invention has the following advantages: (1) The method for preparing aryl[a]carbazole compounds of the present invention does not require any metal catalyst, and the raw materials and reagents used are inexpensive and readily available. The substrates have a wide range of applicability. Various substituted 2-arylindole compounds can be successfully reacted with cyclic or chain α-haloketones (or phenyl or naphthyl-substituted α-haloketones) to prepare a series of aryl[a]carbazole compounds, which have potential practical application value. (2) The method of the present invention can efficiently synthesize a series of aryl[a]carbazole compounds, with mild reaction conditions, simple reaction system, simple operation, and reduced production cost. (3) The preparation method described in this invention has good regioselectivity, fewer side reactions, easy product separation, simple post-processing, and good yield (mostly 80%-90%). In summary, the technical solution of the present invention has the following beneficial effects: The method for preparing aryl[a]carbazole compounds requires no metal catalyst, uses inexpensive and readily available raw materials and reagents (significantly reducing production costs), has a simple reaction system, and is easy to operate. It has broad substrate applicability, good functional group compatibility, mild reaction conditions, fast reaction rate, good chemical selectivity, few side reactions, can be scaled up to gram scale, facilitates the separation of subsequent products, and has a high reaction yield (mostly 80-90%), enabling industrial production and yielding significant economic and social benefits. Detailed Implementation The present invention is described in detail through the following embodiments, but the present invention is not limited to the embodiments. Example 1: 6-Phenyl-11H-benzo[a]carbazole (IIIa1) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIa) (1.1 mmol), p-toluenesulfonic acid (0.3 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-phenyl-11H-benzo[a]carbazole (IIIa1) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. White solid, yield 69%. 1 H NMR(600MHz, CDCl3)δ8.95(s,1H),8.16(d,J=8.0Hz,1H),8.01(d,J=7.8Hz,1H),7.76–7.68(m ,2H),7.68–7.50(m,7H),7.46(d,J=8.0Hz,1H),7.38(t,J=7.6Hz,1H),7.06(t,J=7.5Hz,1H); 13 C NMR (151MHz, CDCl3) δ141.22,138.70,136.59,135.28,132.13,130.72,129.36,128.91,128.60,128.38,127.6 0,125.83,125.70,125.46,124.64,123.86,122.11,120.90,120.36,120.22,119.61,116.74,111.02,110.90. Example 2: 6-(p-methylphenyl)-11H-benzo[a]carbazole (IIIa2) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIb) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(p-methylphenyl)-11H-benzo[a]carbazole (IIIa2) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. White solid (yield 59%, mp: 205-206℃), and the analytical data are consistent with those in the literature. 1 H NMR(600MHz, CDCl3)δ8.89(s,1H),8.14(d,J=8.0Hz,1H),8.01(d,J=7.5Hz,1H),7 .65–7.53(m,2H),7.52(s,1H),7.43–7.35(m,3H),7.12–7.05(m,1H),2.54(s,3H); 13 C NMR (151MHz, CDCl3) δ138.72,138.29,137.29,136.64,135.30,132.20,129.24,129.11,128.88,1 25.67,125.36,124.62,123.97,122.23,120.91,120.37,120.16,119.58,116.87,110.89,21.43. Example 3: 6-(2-chlorophenyl)-11H-benzo[a]carbazole (IIIa3) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIc) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(2-chlorophenyl)-11H-benzo[a]carbazole (IIIa3) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Brown oily substance (yield 57%) 1 H NMR(600MHz, CDCl3)δ8.89(s,1H),8.18(d,J=8.2Hz,1H),8.03(d,J=8.0Hz,1H),7.66–7.61(m,2H),7.61–7 .56(m,2H),7.56–7.51(m,2H),7.51–7.42(m,2H),7.37(ddd,J=8.2,4.6,3.6Hz,1H),7.05(d,J=4.2Hz,2H); 13 C NMR (151MHz, CDCl3) δ139.85,138.55,134.88,133.97,133.29,131.97,131.58,129.61,129.22,129.0 9,126.89,125.76,125.67,124.76,123.83,121.27,120.84,120.54,120.44,119.99,117.20,110.90. Example 4: 6-(2-methoxyphenyl)-11H-benzo[a]carbazole (IIIa4) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IId) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(2-methoxyphenyl)-11H-benzo[a]carbazole (IIIa4) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Gray solid (yield 63%, mp: 173-174℃). 1 H NMR (600MHz, CDCl3) δ8.79(s,1H),8.06(dd,J=10.4,8.4Hz,1H),7.99(dd,J=6.5,2.6Hz,1H),7.54(ddd,J=7.3,4.6,2.2Hz,4H),7. 51–7.46(m,2H),7.38–7.31(m,1H),7.21(d,J=8.0Hz,1H),7.16(ddd,J=17.6,12.1,4.6Hz,2H),7.04(t,J=7.5Hz,1H),3.67(s,3H);13 C NMR (151MHz, CDCl3) δ157.45,138.61,134.86,132.87,132.19,131.40,130.20,129.28,128.90,125.38,125.32,124 .40,124.32,121.49,121.08,120.83,120.44,120.43,119.60,117.67,110.91,110.80,55.64; HRMS(ESI)m / z:[M+H] + calcd for C 23 H 18 NO:324.1383; Found:324.1380. Example 5: 4-(11H-benzo[a]carbazole-6-yl)phenol (IIIa5) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIe) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 4-(11H-benzo[a]carbazole-6-yl)phenol (IIIa5) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Gray solid (yield 62%, mp: 149-150℃). 1 H NMR (600MHz, DMSO-d6) δ11.49(s,1H),9.42(s,1H),7.65(d,J=7.6Hz,2H),7.43(d,J=8.1Hz,1H),7.33(t,J=7.6Hz,2H),7. 21(dt,J=19.7,9.2Hz,3H),7.12(t,J=7.5Hz,1H),6.94(t,J=7.4Hz,1H),6.63(d,J=8.4Hz,2H),5.74(s,1H),5.09(s,1H); 13C NMR(151MHz,DMSO-d6)δ157.55,142.31,136.44,134.85,132.86,131.76,129.40,128.77,128.13 ,127.73,127.65,122.22,119.69,119.59,115.47,113.95,113.89,111.74; HRMS(ESI)m / z:[M+H] + calcd for C 22 H 16 NO:310.1226; Found:310.1219. Example 6: 6-(4-nitrophenyl)-11H-benzo[a]carbazole (IIIa6) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIf) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(4-nitrophenyl)-11H-benzo[a]carbazole (IIIa6) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Yellow solid (yield 56%, mp: 263-264℃), and the analytical data are consistent with those in the literature. 1 H NMR(600MHz,DMSO-d6)δ12.51(s,1H),8.60(d,J=8.2Hz,1H),8.51–8.39(m,2H),8.10(d,J=8.1Hz,1H),8.04–7.91(m, 2H),7.78–7.67(m,2H),7.67–7.60(m,1H),7.57(s,1H),7.44–7.36(m,1H),7.33(d,J=8.0Hz,1H),7.09–6.95(m,1H); 13C NMR (151MHz, DMSO-d6) δ148.13,147.48,139.54,136.39,134.07,131.81,130.82,129.21,126. 62,126.46,125.01,124.24,122.60,122.26,121.34,121.32,120.71,119.59,114.77,112.14. Example 7: 6-(2-naphthyl)-11H-benzo[a]carbazole (IIIa7) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIg) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(2-naphthyl)-11H-benzo[a]carbazole (IIIa7) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Brown oily substance (yield 55%) 1 H NMR(600MHz, CDCl3)δ9.00(s,1H),8.27–8.14(m,2H),8.03(d,J=8.4Hz,2H),8.02–7.98(m,1H),7.98–7.92(m,1 H),7.85(dd,J=8.3,1.7Hz,1H),7.66–7.55(m,6H),7.45(d,J=8.0Hz,1H),7.39–7.34(m,1H),7.02–6.96(m,1H); 13 CNMR(151MHz, CDCl3)δ138.83,138.81,136.46,135.50,133.57,132.89,132.19,128.91,128.26,127.98,127.86,127.83,127.81,12 6.29,126.05,125.73,125.51,124.62,123.82,122.18,121.18,120.59,120.38,119.59,116.75,110.95; HRMS(ESI)m / z:[M+H]+calcd forC22H21N2:313.1699; Found:313.1707. Example 8: 8-Methyl-4-nitro-6-phenyl-11H-benzo[a]carbazole (IIIa8) α-Arylindole (Ib) (1.0 mmol), α-bromoacetophenone (IIa) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 8-methyl-4-nitro-6-phenyl-11H-benzo[a]carbazole (IIIa8) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Yellow solid (yield 51%, mp: 212-213℃). 1 H NMR (600MHz, DMSO-d6) δ11.91(s,1H),8.56–8.48(m,1H),8.11–8.04(m,2H),7.67(t,J=8.0Hz,1H),7.41(d,J=8.3Hz,1 H),7.35–7.33(m,2H),7.31(s,1H),7.28–7.25(m,2H),7.05(dd,J=8.3,1.4Hz,1H),6.96(s,1H),2.32(d,J=3.4Hz,4H); 13 C NMR(151MHz,DMSO-d6)δ148.52,138.68,137.78,135.37,134.33,132.67,132.59,130.76,129.07,128.6 6,128.27,126.94,125.11,122.28,120.91,119.88,119.19,112.05,110.54,21.70; HRMS(ESI)m / z:[M+H] + calcd for C 23 H 17 N2O2:253.1285; Found:253.1280. Example 9: 3-Methyl-6-(p-methylphenyl)-11H-benzo[a]carbazole (IIIa9) α-Arylindole (Ic) (1.0 mmol), α-bromoacetophenone (IIb) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 3-methyl-6-(p-methylphenyl)-11H-benzo[a]carbazole (IIIa9) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. (yield 60%, mp: 210-211℃). 1 H NMR (600MHz, CDCl3) δ8.84(s,1H),8.04(d,J=8.3Hz,1H),7.77(s,1H),7.63–7.58(m,2H),7.56(d,J=8.1Hz,1H),7.51(d,J =8.0Hz,1H),7.42(dd,J=7.6,2.2Hz,2H),7.39–7.33(m,3H),7.06(ddd,J=8.0,7.2,0.9Hz,1H),2.58(s,3H),2.53(s,3H); 13 C NMR (151MHz, CDCl3) δ138.61,138.41,137.18,136.63,135.41,135.36,132.48,129.21,129.05,128.05,127.41 ,124.34,124.05,122.05,120.44,120.24,119.48,118.23,116.25,110.77,21.81,21.40; HRMS(ESI)m / z:[M+H] + calcd for C 24 H 20 N:322.1590; Found:322.1584. Example 10: 6-(2-methoxyphenyl)-3-methyl-11H-benzo[a]carbazole (IIIa10) α-Arylindole (Ic) (1.0 mmol), α-bromoacetophenone (IId) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(2-methoxyphenyl)-3-methyl-11H-benzo[a]carbazole (IIIa10) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Gray solid (yield 62%, mp: 189-190℃). 1 H NMR(600MHz, CDCl3)δ8.73(s,1H),7.94(d,J=8.3Hz,1H),7.75(s,1H),7.58–7.50(m,1H),7.49–7.44(m,3H),7 .36(dd,J=8.3,1.5Hz,1H),7.33–7.28(m,1H),7.20–7.11(m,3H),7.05–7.00(m,1H),3.67(s,3H),2.56(s,3H); 13 C NMR (151MHz, CDCl3) δ157.44,138.49,135.02,134.95,132.82,132.46,131.39,130.33,129.19,128.08,127.35,124.41 ,124.13,121.33,120.79,120.64,120.25,119.52,118.48,117.07,110.92,110.69,55.63,21.79; HRMS(ESI)m / z:[M+H] + calcd for C 24 H 20 NO: 338.1539; Found: 338.1547. Example 11: 6-(2-chlorophenyl)-3-methyl-11H-benzo[a]carbazole (IIIa11) α-Arylindole (Ic) (1.0 mmol), α-bromoacetophenone (IIc) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(2-chlorophenyl)-3-methyl-11H-benzo[a]carbazole (IIIa11) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Yellow oily substance (yield 58%). 1 H NMR (600MHz, CDCl3) δ8.86(s,1H),8.08(d,J=8.3Hz,1H),7.79(s,1H),7.62(d,J=7.8Hz,1H) ,7.59–7.41(m,2H),7.35(t,J=6.3Hz,1H),7.02(d,J=5.9Hz,2H),2.58(s,3H),1.56(s,3H); 13 C NMR (151MHz, CDCl3) δ139.96,138.45,135.41,134.99,133.96,133.28,132.24,131.56,129.58,129.13,128.26,127 .79,126.83,124.49,123.91,121.10,120.35,120.33,119.88,118.61,116.60,110.80,21.79; HRMS(ESI)m / z:[M+H] + calcd for C 23 H 17 ClN:342.1044; Found:342.1039. Example 12: 3-Methyl-6-(4-nitrophenyl)-11H-benzo[a]carbazole (IIIa12) α-Arylindole (Ic) (1.0 mmol), α-bromoacetophenone (IIf) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 3-methyl-6-(4-nitrophenyl)-11H-benzo[a]carbazole (IIIa12) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Yellow solid (yield 53%, mp: 282-283℃). 1 H NMR (600MHz, DMSO-d6) δ12.42(s,1H),8.49(d,J=8.4Hz,1H),8.47–8.38(m,2H),8.01–7.91(m,2H),7.87(s,1H),7.66( d,J=8.1Hz,1H),7.55(dd,J=8.4,1.3Hz,1H),7.46(s,1H),7.42–7.34(m,1H),7.31(d,J=8.0Hz,1H),7.07–6.96(m,1H); 13 C NMR(151MHz,DMSO-d6)δ148.24,147.45,139.45,136.52,135.76,134.11,132.11,130.80,128.56,128.26,12 4.79,124.24,122.69,122.22,121.17,120.26,119.52,119.47,114.23,112.04,21.84; HRMS(ESI)m / z:[M+H] + calcd forC 23 H 17 N2O2:353.1285; Found:353.1280. Example 13: 3-Methyl-6-(2-naphthyl)-11H-benzo[a]carbazole (IIIa13) α-Arylindole (Ic) (1.0 mmol), α-bromoacetophenone (IIg) (1.0 mmol), p-toluenesulfonic acid (0.1 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 3-methyl-6-(2-naphthyl)-11H-benzo[a]carbazole (IIIa13) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent. Brown oily substance (yield 59%). 1 H NMR(600MHz, CDCl3)δ8.91(s,1H),8.18(s,1H),8.12–7.92(m,4H),7.86(dd,J=8.3,1.6Hz,1H),7.8 1(s,1H),7.63–7.52(m,4H),7.45(d,J=8.2Hz,2H),7.35(s,1H),7.00(d,J=7.9Hz,1H),2.59(s,3H); 13 C NMR (151MHz, CDCl3) δ138.94,138.65,136.47,135.54,135.49,133.58,132.88,132.50,128.26,128.15,128.02,127.86,127.81,127 .79,127.60,126.27,126.02,124.43,123.96,122.06,120.83,120.30,119.60,118.39,116.22,110.84,21.83; HRMS(ESI)m / z:[M+H] + calcd for C 27 H 20 N:358.1590; Found:358.1597. Example 14: 6-Phenyl-11H-benzo[a]carbazole (IIIa1) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIa) (1.1 mmol), p-toluenesulfonic acid (0.1 mmol), and xylene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was heated to near boiling. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-phenyl-11H-benzo[a]carbazole (IIIa1) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent, with a yield of 60%. Example 15: 6-Phenyl-11H-benzo[a]carbazole (IIIa1) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIa) (1.1 mmol), p-toluenesulfonic acid (0.3 mmol), and chlorobenzene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was heated to near boiling. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-phenyl-11H-benzo[a]carbazole (IIIa1) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent, with a yield of 50%. Example 16: 6-(p-tolyl)-11H-benzo[a]carbazole (IIIa2) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIb) (1.2 mmol), p-toluenesulfonic acid (0.3 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(p-tolyl)-11H-benzo[a]carbazole (IIIa2) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent, with a yield of 62%. Example 16: 6-(p-tolyl)-11H-benzo[a]carbazole (IIIa2) α-Arylindole (Ia) (1.0 mmol), α-bromoacetophenone (IIb) (0.8 mmol), p-toluenesulfonic acid (0.2 mmol), and toluene (5.0 mL) were added to a 10 mL two-necked flask connected to a reflux condenser. The resulting mixture was stirred at 110 °C. After the reaction was complete, 10 mL of saturated sodium carbonate solution was added to the reaction mixture, and the mixture was extracted successively with ethyl acetate and dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by vacuum distillation. Finally, 6-(p-tolyl)-11H-benzo[a]carbazole (IIIa2) was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent, with a yield of 60%. Example 17: 2,3,4,9-Tetrahydro-1H-dibenzo[a,c]carbazole (IIIb1) Add 1.0 mmol of 2-arylindole (Ia), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the target product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb1). White solid (yield 78%, mp: 165-166℃) 1 H NMR(600MHz, CDCl3)δ8.76(s,1H),8.26(d,J=8.0Hz,1H),8.20–8.03(m,2H),7.58(ddd,J=9.4,7.8,5.3Hz ,3H),7.47–7.38(m,1H),7.35–7.27(m,1H),3.51(s,2H),3.31–3.12(m,2H),2.07(dt,J=6.3,3.3Hz,4H); 13CNMR(151MHz, CDCl3)δ138.52,133.39,131.47,131.35,125.31,124.71,124.38,124.06,124.04,123.44, 122.60,120.64,119.84,119.67,117.55,110.87,109.99,28.99,26.21,23.18,22.89; MS(ESI)m / z:[M+H] + calcd for C 20 H 18 N:272.1; Found:272.4. Example 18: 6-Methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb2) Add 1.0 mmol of 2-arylindole (Ic), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the target product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 6-methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb2). Yellow solid (yield 75%, mp: 181-182℃). 1 H NMR (600MHz, CDCl3) δ8.61(s,1H),8.24(d,J=8.0Hz,1H),7.96(d,J=8.2Hz,1H),7.91(s,1H),7.55(d,J=8.0Hz,1H),7.49–7 .35(m,2H),7.33–7.27(m,1H),3.48(dd,J=7.3,4.0Hz,2H),3.18(d,J=3.0Hz,2H),2.61(s,3H),2.06(dt,J=6.1,2.9Hz,4H); 13C NMR (151MHz, CDCl3) δ138.43,134.89,133.53,131.70,131.33,126.24,124.82,123.79,123.52,122.90,1 22.45,120.57,119.59,117.84,116.92,110.81,29.00,26.25,23.22,22.92,22.29; HRMS(ESI)m / z:[M+H] + calcd forC 21 H 20 N:286.1590; Found:286.1585. Example 19: 6-Methoxy-2,3,4,9-Tetrahydro-1H-dibenzo[a,c]carbazole (IIIb3) Add 1.0 mmol of 2-arylindole (Id), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the target product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 6-methoxy-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb3). White solid (yield 72%, mp: 170-171℃), and the analytical data are consistent with those in the literature. 1 H NMR (600MHz, CDCl3) δ8.59(s,1H),8.22(dt,J=8.0,1.0,1H),7.96(d,J=8.9,1H),7.53(dt,J=8.1,0.9,1H),7.47–7.34(m, 2H),7.35–7.25(m,1H),7.20(dd,J=8.9,2.5,1H),3.98(s,3H),3.46(d,J=4.2,2H),3.13(d,J=5.2,2H),2.18–1.95(m,4H);13 C NMR (151MHz, CDCl3) δ157.52,138.40,133.75,132.92,132.05,124.86,123.62,122.46,12 2.27,119.62,116.06,115.44,114.75,110.75,104.22,55.39,29.01,26.38,23.21,22.88. Example 20: 12-Methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb4) Add 1.0 mmol of 2-arylindole (Ie), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the target product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 12-methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb4). White solid (yield 75%, mp: 187-188℃) 1 H NMR (600MHz, CDCl3) δ8.68(s,1H),8.12(dd,J=7.9,1.6Hz,1H),8.07(dd,J=7.9,1.5Hz,1H),8.04(s,1H),7.55(td,J=7.8,1.3Hz,2H),7. 46(d,J=8.2Hz,1H),7.25(dd,J=8.1,1.6Hz,1H),3.48(dt,J=4.1,2.6Hz,2H),3.20(q,J=3.1Hz,2H),2.59(s,3H),2.06(h,J=2.8Hz,4H); 13C NMR (151MHz, CDCl3) δ136.85,133.72,131.43,131.39,128.79,125.43,125.20,124.92,124.28 ,123.99,123.10,122.53,120.72,119.93,117.33,110.54,29.05,26.21,23.21,22.91,21.82. Example 21: 13-Methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb5) Add 1.0 mmol of 2-arylindole (If), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 13-methyl-2,3,4,9-tetrahydro-1H-dibenzo[a] [a,c]carbazole (IIIb5). White solid (yield 80%, mp: 203-204℃). 1 H NMR(600MHz, CDCl3)δ8.68–8.45(m,1H),8.12(dd,J=7.8,2.0Hz,2H),8.07–8.00(m,1H),7.55(pd,J=6.8,1.5Hz,2 H),7.33(s,1H),7.11(dd,J=8.1,1.4Hz,1H),3.47(q,J=4.7Hz,2H),3.28–3.14(m,2H),2.56(s,3H),2.06(s,4H); 13C NMR (151MHz, CDCl3) δ139.10,134.19,133.20,131.27,125.11,124.37,124.08,123.34,122.53,122. 30,121.38,120.67,119.95,117.68,111.09,29.02,26.27,23.28,22.97,22.01; HRMS(ESI)m / z:[M+H] + calcd for C 21 H 20 N: 286.1950; Found: 286.1957. Example 22: 6,12-Dimethyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb6) Add 2-arylindole (Ig) (1.0 mmol), 2-chlorocyclohexanone (IIh) (1.0 mmol), and 5.0 mL of hydrogen chloride-saturated ethanol solution to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 6,12-dimethyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb6). White solid (yield 82%, mp: 179-180℃). 1 H NMR (600MHz, CDCl3) δ8.57(s,1H),8.02(d,J=1.6Hz,1H),7.97(d,J=8.2Hz,1H),7.89(s,1H),7.45(d,J=8.1Hz,1H),7.38(dd,J=8.3,1.6H z,1H),7.23(dd,J=8.2,1.6Hz,1H),3.48(dt,J=4.3,2.5Hz,2H),3.18(dt,J=4.8,2.5Hz,2H),2.60(s,3H),2.58(s,3H),2.18–1.89(m,4H); 13C NMR (151MHz, CDCl3) δ136.72,134.80,133.84,131.64,131.44,128.75,126.19,125.18,125.05,123.50,122. 63,122.41,120.56,117.93,116.74,110.41,29.07,26.25,23.24,22.94,22.27,21.80; HRMS(ESI)m / z:[M+H] + calcd for C 22 H 22 N:300.1747; Found:300.1754. Example 23: 6-Ethyl-12-methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb7) Add 1.0 mmol of 2-arylindole (Ih), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 6-ethyl-12-methyl-2,3,4,9-tetrahydro-1H- Dibenzo[a,c]carbazole (IIIb7). White solid (yield 85%, mp: 184-185℃). 1H NMR (600MHz, CDCl3) δ8.54 (s, 1H), 8.06–8.01 (m, 1H), 7.98 (d, J = 8.3Hz, 1H), 7.91 (d,J=1.6Hz,1H),7.44(d,J=8.2Hz,1H),7.41(dd,J=8.2,1.6Hz,1H),7.24(dd,J=8 .2,1.6Hz,1H),3.47(tt,J=4.8,2.3Hz,2H),3.20(dt,J=6.5,3.1Hz,2H),2.90(q,J =7.6Hz,2H),2.59(s,3H),2.12–1.98(m,J=4.0,3.5Hz,4H),1.39(t,J=7.6Hz,3H); 13 C NMR (151MHz, CDCl3) δ141.24,136.75,133.87,131.66,131.40,128.72,125.16,125.08,125.06,122.77,122.43, 122.27,120.70,118.16,116.78,110.45,29.69,29.07,26.28,23.26,22.96,21.82,16.07; HRMS(ESI)m / z:[M+H] + calcd for C 23 H 24 N:314.1903; Found:314.1906. Example 24: 12-(trifluoromethoxy)-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb8) Add 1.0 mmol of 2-arylindole (Ii), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 12-(trifluoromethoxy)-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb8). White solid (yield 78%, mp: 101-102℃). 1 H NMR (400MHz, CDCl3) δ8.81(s,1H),8.14–8.05(m,2H),8.05(d,J=1.6Hz,1H),7.64–7.53(m,2H),7.50(d,J=8.8Hz,1H ),7.29(ddd,J=8.6,2.3,1.1Hz,1H),3.37(dd,J=4.0,2.3Hz,2H),3.16(s,2H),2.49–2.24(m,2H),1.70–1.65(m,2H); 13 C NMR (101MHz, CDCl3) δ142.72,142.71,136.76,134.69,131.85,130.95,125.84,124.84,124.62,124.16,123.99,120.75 ,119.83,117.71,117.36,115.43,111.23,77.43,77.11,76.79,34.08,28.74,26.18,24.52,23.10; HRMS(ESI)m / z:[M+H] + calcd for C 21 H 17 F3NO:356.1257; Found:356.1250. Example 25: 10,13-Dimethyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb9) Add 1.0 mmol of 2-arylindole (Ij), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 10,13-dimethyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb9). White solid (yield 66%, mp: 217-218℃).1 H NMR(400MHz, CDCl3)δ8.66(s,1H),8.20–8.15(m,1H),8.15–8.08(m,1H),7.61–7.54(m,2H),7.16–7.09(m,1H),7.01(d, J=7.0Hz,1H),3.60–3.52(m,2H),3.26(t,J=6.5Hz,2H),3.00(s,3H),2.64(s,3H),2.12–2.04(m,2H),1.94–1.86(m,2H); 13 C NMR (101MHz, CDCl3) δ138.59,133.64,131.45,131.14,129.57,125.54,125.01,124.52,123.92,123.62,123.60, 123.54,123.08,120.56,120.06,119.57,117.47,33.63,27.14,23.56,23.24,16.91,16.85; HRMS(ESI)m / z:[M+H] + calcdfor C 22 H 22 N:300.1747; Found:300.1742. Example 26: 5,6,7-trimethoxy-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb10) Add 1.0 mmol of 2-arylindole (Ik), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 5,6,7-trimethoxy-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb10). White solid (yield 88%, mp: 169-170℃). 1H NMR(600MHz, CDCl3)δ9.91(s,1H),8.26(dd,J=8.0,1.1Hz,1H),7.60(dt,J=8.1,0.9Hz,1H),7.41(d,J=1.1Hz,1H),7.31–7.26(m,1H ),7.22(s,1H),4.24(s,3H),4.05(s,3H),4.03(s,3H),3.58–3.44(m,2H),3.11(dd,J=3.7,2.1Hz,2H),2.07(tq,J=4.4,2.0Hz,4H); 13 C NMR (151MHz, CDCl3) δ152.17,148.68,139.49,138.01,132.41,131.55,128.99,123.57,123.54,122.18,121.64 ,119.19,116.42,110.77,109.97,99.90,61.48,61.30,55.93,29.00,26.75,23.32,22.93; HRMS(ESI)m / z:[M+H] + calcd for C 23 H 24 NO3:362.1751; Found:362.1759. Example 27: 5,6,7-Trimethoxy-12-methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb11) Add 2-arylindole (Il) (1.0 mmol), 2-chlorocyclohexanone (IIh) (1.0 mmol), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. The residue was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as elution to obtain 5,6,7-trimethoxy-12-methyl-2,3,4,9-tetrahydro-1H-dibenzo[a,c]carbazole (IIIb11). White solid (yield 89%, mp: 182-183℃). 1H NMR (400MHz, CDCl3) δ9.82(s,1H),8.04(dd,J=1.7,0.9Hz,1H),7.49(d,J=8.2Hz,1H),7.24(dd,J=8.1,1.6Hz,1H),7.21(s ,1H),4.23(s,3H),4.04(s,3H),4.03(s,3H),3.53–3.46(m,2H),3.11(d,J=6.3Hz,2H),2.58(s,3H),2.06(p,J=3.2Hz,4H); 13 C NMR (151MHz, CDCl3) δ152.12,148.74,139.48,136.35,132.71,131.71,128.97,128.36,125.02,123.81,122.18,12 1.38,116.23,110.46,110.06,99.89,61.55,61.37,55.99,29.14,26.83,23.40,23.00,21.93; HRMS(ESI)m / z:[M+H] + calcd for C 24 H 26 NO3:376.1907; Found:376.1913. Example 28: 8,9,10,15-Tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb12) Add 2-arylindole (Im) (1.0 mmol), 2-chlorocyclohexanone (IIh) (1.0 mmol), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb12). Yellow solid (yield 80%, mp: 181-182℃). 1H NMR (600MHz, CDCl3) δ8.93–8.85(m,1H),8.74(s,1H),8.31(d,J=8.0Hz,1H),8.03(d,J=8.6Hz,1H),7.96(dd,J=7.4,2.0Hz,1H),7.82(d,J=8.6Hz,1 H),7.64–7.55(m,3H),7.50–7.44(m,1H),7.31(t,J=7.5Hz,1H),3.79–3.5 3(m,4H),2.19(t,J=5.9Hz,2H),1.88(dd,J=7.5,4.1Hz,2H),1.58(s,4H); 13 CNMR(151MHz, CDCl3)δ139.47,134.44,133.55,132.68,131.56,128.74,128.72,127.07,126.28,125.40,1 24.92,124.78,124.52,123.27,119.79,119.71,110.87,34.56,29.88,24.66,23.03; HRMS(ESI)m / z:[M+H] + calcd for C 24 H 20 N:322.1590; Found:322.1596. Example 29: 12-Methyl-8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb13) Add 1.0 mmol of 2-arylindole (In), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 12-methyl-8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb13). Pale yellow solid (yield 87%, mp: 259-260℃).1 H NMR (600MHz, DMSO-d6) δ11.96(s,1H),8.92–8.78(m,1H),8.46(d,J=8.7Hz,1H),8.08–8.00(m,2H),7.93(d,J=8.7Hz,1H),7.61(ddd,J=6.5,4.0,1 .8Hz,2H),7.56(d,J=8.2Hz,1H),7.27(dd,J=8.3,1.6Hz,1H),3.57(t,J=6.3Hz,4H),2.53(s,3H),2.12(dd,J=8.2,3.6Hz,2H),1.88–1.69(m,2H); 13 CNMR(151MHz,DMSO-d6)δ138.46,135.48,133.61,132.58,131.22,129.02,128.64,128.57,127.95,126.31,126.18,125.73 ,125.62,125.35,123.87,123.02,121.53,118.30,118.03,111.24,34.27,29.85,24.72,22.89,21.94; HRMS(ESI)m / z:[M+H] + calcd for C 25 H 22 N: 336.1747; Found: 336.1741. Example 30: 4-Methoxy-8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb14) Add 2-arylindole (Io) (1.0 mmol), 2-chlorocyclohexanone (IIh) (1.0 mmol), and 5.0 mL of hydrogen chloride-saturated ethanol solution to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to give 4-methoxy-8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb14). Yellow solid (yield 72%, mp: 263-264℃). 1 H NMR (600MHz, CDCl3) δ8.82(d,J=9.3Hz,1H),8.68(s,1H),8.28(d,J=7.9Hz,1H),7 .96(d,J=8.7Hz,1H),7.70(d,J=8.7Hz,1H),7.57(dt,J=8.0,0.9Hz,1H),7.44(ddd ,J=8.1,7.1,1.1Hz,1H),7.33–7.28(m,2H),7.24(dd,J=9.3,2.9Hz,1H),3.98(s, 3H),3.63(t,J=6.8Hz,2H),3.60(t,J=5.9Hz,2H),2.16(s,2H),1.89–1.84(m,2H); 13 C NMR (151MHz, CDCl3) δ156.91,139.31,135.12,134.55,132.68,130.16,129.45,126.31,126.01,125.65,124.55,124.46,1 23.03,120.26,119.66,118.14,116.49,115.07,110.74,108.65,55.36,34.50,29.84,24.58,22.93; HRMS(ESI)m / z:[M+H] + calcd for C 25 H 22 NO:352.1696; Found:352.1690. Example 31: 4-Methoxy-12-methyl-8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb15) Add 1.0 mmol of 2-arylindole (Ip), 1.0 mmol of 2-chlorocyclohexanone (IIh), and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the indole is completely consumed. Remove the solvent from the reaction mixture by vacuum distillation. Heat the resulting oily residue to 120 °C until the α-carbonylindole intermediate is completely converted to the product. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent by vacuum distillation. The residue was purified by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as elution to obtain 4-methoxy-12-methyl-8,9,10,15-tetrahydro-7H-benzo[c]naphtho[2,1-a]carbazole (IIIb15). Yellow solid (yield 69%, mp: 289-290℃). 1 H NMR (600MHz, DMSO-d6) δ11.88(s,1H),8.77(d,J=9.4Hz,1H),8.42(d,J=8.8Hz,1H),8.03(d,J=1.6Hz,1H),7.87(d,J=8.8Hz,1H),7 .62–7.45(m,2H),7.32–7.14(m,2H),3.94(s,3H),3.54(dt,J=18.0,6.3Hz,4H),2.52(s,3H),2.26–2.03(m,2H),1.88–1.69(m,2H); 13 C NMR(151MHz,DMSO-d6)δ156.98,138.31,135.65,135.37,132.58,130.12,128.92,127.87,126.04,125.78,125.64,124.96,123 .97,122.87,122.03,117.31,117.21,115.46,111.15,109.25,55.66,34.27,29.89,24.73,22.89,21.94; HRMS(ESI)m / z:[M+H] + calcd for C 26 H 24 NO: 366.1852; Found: 366.1858. Example 32: 3,4-Dimethoxy-5,6-dimethyl-11H-benzo[a]carbazole (IIIc1) Add 1.0 mmol of 2-arylindole (Iq), 1.0 mmol of 3-chloro-2-butanone, and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the reaction is complete. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to obtain 3,4-dimethoxy-5,6-dimethyl-11H-benzo[a]carbazole (IIIc1) and 2,3-dimethoxy-5,6-dimethyl-11H-benzo[a]carbazole (IIIc2). 3,4-Dimethoxy-5,6-dimethyl-11H-benzo[a]carbazole (IIIc1), white solid (yield 40%, mp: 181-182-238℃), and the analytical data are consistent with those in the literature. 1 H NMR (600MHz, CDCl3) δ8.34(s,1H),7.47(d,J=7.8Hz,1H),7.37(d,J=7.9Hz,2H),7.23–7.20(m,2H),7.19–7.08(m,3H),6.9 4(d,J=8.3Hz,1H),3.92(s,7H),2.38(d,J=0.4Hz,1H),2.18(d,J=1.4Hz,3H),1.98(d,J=0.5Hz,1H),1.94(d,J=1.4Hz,3H); 13 C NMR (151MHz, CDCl3) δ149.23,148.76,135.67,133.28,129.05,128.24,126.11,125.51,122.42,120.1 8,119.47,118.64,111.53,110.87,110.86,109.82,55.93,55.84,23.75,21.28; HRMS(ESI)m / z:[M+H] + calcd for C 20 H 20 NO2:306.1489; Found:306.1495. 2,3-Dimethoxy-5,6-dimethyl-11H-benzo[a]carbazole (IIIc2), white solid (yield 33%, mp: 176-177℃). 1 H NMR (600MHz, DMSO-d6) δ11.87(s,1H),8.22(d,J=8.0Hz,1H),7.96(s,1H),7.60(d,J=8.0Hz,1H),7.43(s,1H), 7.41–7.31(m,1H),7.24–7.10(m,1H),4.00(d,J=5.5Hz,3H),3.97(d,J=11.9Hz,3H),2.90(s,3H),2.64(s,3H); 13 C NMR (151MHz, DMSO-d6) δ148.96,148.27,139.19,134.26,127.27,127.16,124.46,123.83,122.07,120. 58,119.14,116.35,115.13,111.34,105.66,102.92,56.04,55.85,17.76,14.87; HRMS(ESI)m / z:[M+H] + calcd for C 20 H 20 NO2:306.1489; Found:306.1488. Example 33: 3,4-Dimethoxy-5,6,8-trimethyl-11H-benzo[a]carbazole (IIIc3) Add 1.0 mmol of 2-arylindole (Ir), 1.0 mmol of 3-chloro-2-butanone, and 5.0 mL of ethanol saturated with hydrogen chloride to a 10 mL two-necked flask connected to a reflux condenser. Stir the mixture at 80 °C. Monitor the reaction progress by thin-layer chromatography (TLC) until the reaction is complete. Subsequently, dissolve the reactants in 10 mL of saturated sodium carbonate solution and extract with ethyl acetate or dichloromethane (3 × 10 mL). Combine the organic phases, dry with anhydrous sodium sulfate, filter, and evaporate the solvent under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as eluent to obtain 3,4-dimethoxy-5,6,8-trimethyl-11H-benzo[a]carbazole (IIIc3). 3,4-Dimethoxy-5,6,8-trimethyl-11H-benzo[a]carbazole (IIIc3), white solid (yield 49%, mp: 170-171℃). 1H NMR (600MHz, CDCl3) δ8.14(s,1H),7.33–7.30(m,1H),7.22(d,J=2.0Hz,1H),7.14(dd,J=8.3,2.0Hz,1H),7.07(d,J= 7.8Hz,1H),6.98(d,J=8.3Hz,1H),3.97(s,3H),3.96(s,3H),2.50(s,3H),2.19(q,J=1.4Hz,3H),2.01–1.89(m,3H); 13 C NMR (151MHz, CDCl3) δ149.21,148.68,133.94,133.33,129.53,128.91,128.49,126.20,125.60,124.02,1 19.07,118.44,113.02,111.46,110.46,109.70,55.93,55.84,23.73,21.56,21.25; HRMS(ESI)m / z:[M+H] + calcd for C 21 H 22 NO2:320.1645; Found:320.1649. 2,3-Dimethoxy-5,6,8-trimethyl-11H-benzo[a]carbazole (IIIc4), white solid (yield 27%, mp: 163-164℃). 1 H NMR(600MHz, CDCl3)δ8.50(s,1H),8.08(s,1H),7.44(d,J=8.1Hz,1H),7.42(s,1H),7.31(s,1H), 7.22(dd,J=8.1,0.8Hz,1H),4.063(s,3H),4.055(s,3H),2.96(s,3H),2.67(s,3H),2.58(s,3H); 13 C NMR(151 MHz, CDCl3)δ148.61,147.97,136.99,133.62,128.65,127.95,127.21,125.41,125.13,122.24,121. 09,117.26,114.47,110.35,105.31,100.60,55.97,55.85,21.84,17.60,14.66; HRMS(ESI)m / z:[M+H] + calcd forC 21 H 22 NO2:320.1645; Found:320.1650.

Claims

1. A method for preparing aryl[a]carbazole compounds from α-haloketones and 2-arylindole compounds, characterized in that, Under acidic conditions, the 2-arylindole compound represented by general formula (I) reacts with the α-haloketone represented by general formula (II) in a solvent to give the aryl[a]carbazole compound represented by general formula (III), and the chemical reaction formula is shown below: Where R 1 Selected from H, C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkoxy; R 2 Selected from H, C1-C6 alkyl, C1-C6 alkoxy, or nitro groups; R 3 Selected from H, C1-C6 alkyl or C1-C6 alkoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or an alkyl or alkoxy-substituted benzene ring; R 4 Selected from H, C1-C6 alkyl or C1-C6 alkoxy groups; R 5 Selected from hydrogen or C1-C6 alkyl groups; R 6 Selected from C1-C6 alkyl, phenyl, substituted phenyl, or naphthyl groups; R 7 Selected from H, C1-C6 alkyl or C1-C6 alkoxy; or R 6 and R 7 They connect together to form -(CH2). n - where n = 3-6; X is a halogen.

2. The method for preparing aryl[a]carbazole compounds as described in claim 1, characterized in that, Where R 1 Selected from H, C1-C4 alkyl, C1-C4 alkoxy, or C1-C4 haloalkoxy; R 2 Selected from H, C1-C4 alkyl, C1-C4 alkoxy, or nitro groups; R 3 Selected from H, C1-C4 alkyl or C1-C4 alkoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or a C1-C4 alkyl or C1-C4 alkoxy-substituted benzene ring; R 4 Selected from H, C1-C4 alkyl or C1-C4 alkoxy groups; R 5 Selected from hydrogen or C1-C4 alkyl groups; R 6 Selected from C1-C4 alkyl, phenyl, substituted phenyl, or naphthyl groups, wherein the substituent on the benzene ring of the substituted phenyl group is selected from C1-C4 alkyl, C1-C4 alkoxy, halogen, hydroxy, or nitro groups; R 7 Selected from H, C1-C4 alkyl or C1-C4 alkoxy; or R 6 and R 7 They connect together to form -(CH2). n - where n = 4; X is a halogen.

3. The method for preparing aryl[a]carbazole compounds as described in claim 2, characterized in that, Where R 1 Selected from H, C1-C2 alkyl, C1-C2 alkoxy, or C1-C2 haloalkoxy; R 2 Selected from H, C1-C2 alkyl, C1-C2 alkoxy, or nitro groups; R 3 Selected from H, C1-C2 alkyl or C1-C2 alkoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or a C1-C2 alkyl or C1-C2 alkoxy-substituted benzene ring; R 4 Selected from H, C1-C2 alkyl or C1-C2 alkoxy groups; R 5 Selected from hydrogen or C1-C2 alkyl groups; R 6 Selected from C1-C2 alkyl, phenyl, substituted phenyl, or naphthyl groups, wherein the substituent on the benzene ring of the substituted phenyl group is selected from C1-C2 alkyl, C1-C2 alkoxy, halogen, hydroxy, or nitro groups; R 7 Selected from H, C1-C2 alkyl or C1-C2 alkoxy; or R 6 and R 7 They connect together to form -(CH2). n - where n = 4; X is chlorine or bromine.

4. The method for preparing aryl[a]carbazole compounds as described in claim 3, characterized in that, Where R 1 Selected from H, methyl, or trifluoromethoxy; R 2 Selected from H, methyl, methoxy, or nitro; R 3 Selected from H, methyl, ethyl, or methoxy; or R 2 and R 3 Together with the carbon atoms attached to them, they form a benzene ring, or a methoxy-substituted benzene ring; R 4 Selected from H, methyl, or methoxy; R 5 It is hydrogen; R 6 Selected from methyl, phenyl, tolyl, chlorophenyl, methoxyphenyl, hydroxyphenyl, nitrophenyl, or 2-naphthyl; R 7 Selected from H or methyl; or R 6 and R 7 They connect together to form -(CH2). n - where n = 4; X is chlorine or bromine.

5. The method for preparing aryl[a]carbazole compounds as described in claim 1, characterized in that: The acidic conditions are HCl or TsOH; the solvent is an alcohol solvent or an aromatic solvent; and the reaction temperature is 0-150℃.

6. The method for preparing aryl[a]carbazole compounds as described in claim 5, characterized in that: The acidic conditions are HCl or TsOH; the alcohol solvent is ethanol; the aromatic solvent is benzene, toluene, xylene, or chlorobenzene; and the reaction temperature is 60-150℃.

7. The method for preparing aryl[a]carbazole compounds as described in claim 6, characterized in that: When the acidic condition is TsOH, the solvent is toluene; when the acidic condition is HCl, the solvent is ethanol.

8. The method for preparing aryl[a]carbazole compounds as described in claim 7, characterized in that: The reaction temperature is 70-120℃; when the acidic conditions are inorganic acid (HCl) and the solvent is ethanol, the specific operation is as follows: add an ethanol solution saturated with hydrogen chloride gas; the molar ratio of the 2-arylindole compound represented by general formula (I) to the α-haloketone represented by general formula (II) is 1:(0.8-1.2).

9. The method for preparing aryl[a]carbazole compounds as described in claim 1, characterized in that: The operation steps are as follows: Under acidic conditions, the solvent, the 2-arylindole compound represented by general formula (I), and the α-haloketone represented by general formula (II) are heated and reacted. After the reaction is completed, the aryl[a]carbazole compound represented by general formula (III) is obtained by separation and purification.

10. The method for preparing aryl[a]carbazole compounds as described in claim 9, characterized in that: The separation and purification procedure after the reaction is completed is as follows: saturated sodium carbonate solution is added to the reaction mixture, and the mixture is extracted with ethyl acetate and dichloromethane in sequence. The organic phases are combined, dried with anhydrous sodium sulfate, filtered, and the solvent is removed by vacuum distillation. Finally, the aryl[a]carbazole compound is obtained by silica gel column chromatography using a mixture of n-hexane and ethyl acetate as the eluent.

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