CN118619946A - Indolo[3,2-c]quinoline derivatives and their synthesis methods and applications - Google Patents

Abstract

The invention discloses a series of indolo [3,2-c ] quinoline derivatives, and a synthesis method and application thereof. The indolo [3,2-c ] quinoline derivative has a structure shown in the following formula (I), and is prepared by reacting a compound shown in the formula (II) and a compound shown in the formula (III) in an organic solvent with or without adding a catalyst under the condition of heating or without heating. The test results of the applicant show that part of target compounds of the invention have better anti-inflammatory activity and certain potential medicinal value. The structures of the compounds shown in the formula (I), the formula (II) and the formula (III) are respectively as follows:

Description

Indolo[3,2-c]quinoline derivatives and their synthesis methods and applications

Technical Field

The invention relates to indolo[3,2-c]quinoline derivatives and synthesis methods and applications thereof, belonging to the technical field of medicines.

Background Art

Nitrogen heterocyclic compounds occupy an important position in natural products and biologically active molecules in nature. Among them, nitrogen heterocyclic compounds containing indole and quinoline are extremely important structural elements, existing in various biological and medicinal active molecules, agricultural chemicals, dyes and essential oils, and usually have antibacterial, anticancer and ulcerogenic effects. Quinoline derivatives are the core skeletons of many natural products and drug molecules. As important drug intermediates, they are widely used in drug screening, chemical analysis and other fields. Due to the importance of tetrahydroquinoline, people have been committed to developing synthetic methods that can obtain tetrahydroquinoline skeletons. Therefore, it is of great significance to develop new strategies to construct indole [3,2-c] quinoline.

Summary of the invention

The technical problem to be solved by the present invention is to provide a series of indolo[3,2-c]quinoline derivatives with novel structures and good anti-inflammatory activity, as well as synthesis methods and applications thereof.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

The indolo[3,2-c]quinoline derivative of the present invention is an indolo[3,2-c]quinoline derivative having a structure represented by the following formula (I) or a pharmaceutically acceptable salt thereof:

in:

^R1 represents furanyl, thienyl or naphthyl, or represents unsubstituted, monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted phenyl, wherein the substituent is _C1-4 alkyl, _C1-4 alkoxy, _C1-4 perfluoroalkyl, cyano or halogen atom;

^R2 represents a hydrogen atom, a benzyl group, an alkynyl group, a propargyl group or a _C1-4 alkyl group;

R ³ represents a hydrogen atom, a halogen atom, a cyano group, a C _1-4 alkyl group, a C _1-4 alkoxy group or a C _1-4 perfluoroalkyl group.

In the general structure of the above-mentioned indolo[3,2-c]quinoline derivative, each substituent is preferably as follows:

^R1 represents an unsubstituted, monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted phenyl group, wherein the substituent is a _C1-4 alkyl group, a _C1-4 alkoxy group, a _C1-4 perfluoroalkyl group or a halogen atom;

^R2 represents a hydrogen atom, a benzyl group, an alkynyl group, a propargyl group or a _C1-4 alkyl group;

R ³ represents a hydrogen atom, a halogen atom, a C _1-4 alkyl group, a C _1-4 alkoxy group or a C _1-4 perfluoroalkyl group.

Furthermore, in the general structure of the above-mentioned indolo[3,2-c]quinoline derivative, each substituent is more preferably as follows:

^R1 represents a phenyl, 4-methoxyphenyl, 4-methylphenyl, 4-chlorophenyl, 4-bromophenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 3,5-dimethylphenyl, 2-methyl or furan ring;

^R2 represents a hydrogen atom, a benzyl group, a propargyl group or a methyl group;

R ³ represents a hydrogen atom, a 3-methyl group, a 4-methyl group, a 3,5-methyl group, a 4-methoxy group, a 4-chlorine atom, a 4-bromine atom, a 4-fluorine atom, a 4-trifluoromethyl group or a 2-bromine atom.

Furthermore, the indolo[3,2-c]quinoline derivative of the present invention can be any one of the following compounds 4aa to 4aj:

4aa: R ¹ =Ph, R ² =Me, R ³ =H;

4ba: R ¹ =4-OMe-Ph, R ² =Me, R ³ =H;

4ca: R ¹ =4-Me-Ph, R ² =Me, R ³ =H;

4da: R ¹ =4-Cl-Ph, R ² =Me, R ³ =H;

4ea: R ¹ =4-Br-Ph, R ² =Me, R ³ =H;

4fa: R ¹ =4-F-Ph, R ² =Me, R ³ =H;

4ga: R ¹ =4-CF ₃ -Ph, R ² =Me, R ³ =H;

4ha: R ¹ =3,5-Me-Ph, R ² =Me, R ³ =H;

4ia: R ¹ =2-Me-Ph, R ² =Me, R ³ =H;

4ja: R ¹ = furan ring, R ² = Me, R ³ = H;

4ka: R ¹ =Ph, R ² =-CH ₂ -Ph, R ³ =H;

4la: R ¹ =2-Me-Ph, R ² =propargyl, R ³ =H;

4ab: R ¹ =Ph, R ² =Me, R ³ =4-OMe;

4ac: R ¹ =Ph, R ² =Me, R ³ =4-Me;

4ad: R ¹ =Ph, R ² =Me, R ³ =4-Cl;

4ae: R ¹ =Ph, R ² =Me, R ³ =4-Br;

4af: R ¹ =Ph, R ² =Me, R ³ =4-F;

4ag: R ¹ =Ph, R ² =Me, R ³ =4-CF ₃ ;

4ah: R ¹ =Ph, R ² =Me, R ³ =3-Me;

4ai: R ¹ =Ph, R ² =Me, R ³ =3,5-Me;

4aj: R ¹ =Ph, R ² =Me, R ³ =2-Br.

The synthesis method of the indolo[3,2-c]quinoline derivative of the present invention mainly comprises the following steps: placing a compound represented by the following formula (II) and a compound represented by the following formula (III) in an organic solvent, adding or not adding a catalyst in the presence of an alkaline substance, and reacting under heating or no heating to obtain a crude target compound;

^R1 represents furanyl, thienyl or naphthyl, or represents unsubstituted, monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted phenyl, wherein the substituent is _C1-4 alkyl, _C1-4 alkoxy, _C1-4 perfluoroalkyl, cyano or halogen atom;

^R2 represents a hydrogen atom, a benzyl group, an alkynyl group, a propargyl group or a _C1-4 alkyl group;

R ³ represents a hydrogen atom, a halogen atom, a cyano group, a C _1-4 alkyl group, a C _1-4 alkoxy group or a C _1-4 perfluoroalkyl group.

In the above synthesis method, the preferred selections of R ¹ , R ² and R ³ are as described above.

In the above synthesis method, the addition of a catalyst can improve the yield of the target compound. The catalyst can be one or a combination of two or more selected from copper salts, ytterbium salts and scandium salts; wherein the copper salt is preferably one or a combination of two or more selected from copper bromide, copper iodide, copper chloride, copper sulfate, acetic acid ketone, copper trifluoromethanesulfonate, cuprous bromide, cuprous iodide and cuprous chloride; the ytterbium salt is preferably ytterbium trifluoromethanesulfonate; the scandium salt is preferably scandium trifluoromethanesulfonate. The amount of the catalyst is preferably 0.1 to 0.5 times the amount of the compound represented by formula (II).

In the above synthesis method, the organic solvent is preferably selected from one or more of benzene, toluene, cyclohexane, petroleum ether, carbon tetrachloride, tetrahydrofuran, ethyl acetate, acetonitrile, ether, dichloromethane, acetone, chloroform, n-hexane and dioxane, and is more preferably ethyl acetate. The amount of the organic solvent used is preferably such that it can dissolve the raw materials participating in the reaction. Under normal circumstances, based on 1 mmol of the compound represented by formula (II), all the raw materials participating in the reaction are usually dissolved in 1 to 10 mL of the organic solvent.

In the above-mentioned synthesis method, the presence of alkaline substances enables the reaction to proceed in a favorable manner, and the alkaline substances play a role in increasing the nucleophilicity of the oxime and promoting the generation of the intermediate (nitrone). The alkaline substance can be a conventional choice of the prior art, preferably one or a combination of two or more selected from tripotassium phosphate, sodium hydroxide, potassium hydroxide, calcium hydroxide, cesium hydroxide, cesium carbonate, potassium carbonate, potassium tert-butoxide, sodium tert-butoxide, potassium fluoride, pyridine, triethylamine and N,N-diisopropylethylamine. When the alkaline substance is a combination of the above two or more substances, their ratio can be any ratio. The amount of the alkaline substance is preferably 1 to 2 times the amount of the compound substance shown in formula (II).

In the above-mentioned synthesis method, the reaction is carried out under heating conditions to increase the reaction rate and is also more conducive to increasing the yield of the target compound. Preferably, the reaction is carried out under conditions of ≥40°C, and more preferably under conditions of 50-80°C. The reaction is followed by TLC detection until the reaction is complete. According to the applicant's experience, when the reaction is carried out under conditions of 50-80°C, it is more appropriate to control the reaction time to 5-24h.

In the synthesis method described in the present invention, the raw material compound represented by formula (II) is alkynyl oxime, which can be synthesized with reference to existing literature (Ma, X.-P.; Li, K.; Wu, S.-Y.; Liang, C.; Su, G.-F.; Mo, D.-L. Green Chem., 2017, 19, 5761-5766.), or a self-designed route can be used for synthesis, which will not be described in detail here. The raw material compound represented by formula (III) is diaryl iodide salt, which can be synthesized with reference to existing literature (Merritt, E.A.; Olofsson, B. Angew. Chem., Int. Ed. 2009, 48, 9052.), or a self-designed route can be used for synthesis, which will not be described in detail here. The dosage ratio of the compound represented by formula (II) and the compound represented by formula (III) is a stoichiometric ratio. In actual operation, the molar ratio of the compound represented by formula (II) and the compound represented by formula (III) is usually 1:2 to 3.

The crude product of the compound of formula (I) is obtained by the above method, so the method of the present invention further includes the step of purifying the obtained crude product of the target compound. Specifically, the compound of formula (I) can be purified by conventional purification methods to improve the purity of the compound of formula (I), such as silica gel thin layer chromatography or silica gel column chromatography, or recrystallization. The eluent used in chromatography is the same as the solvent used in recrystallization, which can be a mixed solvent composed of petroleum ether and ethyl acetate in a volume ratio of 50:1 to 30:1, or a mixed solvent composed of n-hexane and ethyl acetate in a volume ratio of 50:1 to 30:1.

The applicant has found through experiments that the indolo[3,2-c]quinoline derivatives of the present invention have good anti-inflammatory activity. Based on this, the present invention also provides the use of the above-mentioned indolo[3,2-c]quinoline derivatives or their pharmaceutically acceptable salts in the preparation of drugs for treating inflammation, and further in the preparation of drugs for treating inflammation caused by lipopolysaccharide.

Furthermore, the present invention also includes a pharmaceutical composition comprising a therapeutically effective dose of the above-mentioned indolo[3,2-c]quinoline derivative or a pharmaceutically acceptable salt thereof as an active ingredient, and at least one pharmaceutically acceptable carrier.

Compared with the prior art, the present invention provides a series of novel indolo[3,2-c]quinoline derivatives and their synthesis methods. The applicant's test results show that some of the target compounds of the present invention have a good inhibitory effect on the release of NO in mouse macrophages RAW 264.7 induced by lipopolysaccharide, and are expected to be used in the preparation of drugs for treating inflammation.

DETAILED DESCRIPTION

In order to better explain the technical solution of the present invention, the present invention is further described in detail below in conjunction with embodiments, but the embodiments of the present invention are not limited thereto.

The diaryl iodonium salt derivatives involved in the following embodiments are synthesized according to the following synthetic route:

Here, R ³ represents a hydrogen atom, a halogen atom, a cyano group, a C _1-4 alkyl group, a C _1-4 alkoxy group or a C _1-4 perfluoroalkyl group.

The specific synthesis method is as follows: dissolve arylboronic acid (10 mmol, 1.0 equiv) in 40.0 mL of dichloromethane, cool to 0°C, slowly dropwise add BF ₃ ·OEt (boron trifluoride etherate, 1.12 mL, 1.10 equiv), continue stirring for 10 min, slowly dropwise add aryl iodobenzene diacetic acid (1.05 equiv) dissolved in 20.0 mL of dichloromethane to the reaction solution, continue stirring at 0°C for 15 min, then return to room temperature and continue stirring for 1 h, stir the reaction solution at 0°C again, dropwise add TfOH (trifluoromethanesulfonic acid, 1.67 mL, 1.1 equiv) to the reaction solution, continue stirring for 10 min, return to room temperature and stir for 15 min, post-process, remove the solvent under reduced pressure, pour the residual liquid into 5 cm silica, and filter it with 5% MeOH/CH ₂ The solution was concentrated and then recrystallized with ether to obtain a white solid, which is the diaryl iodonium salt of the compound represented by formula (III).

Example 1

The indolo[3,2-c]quinoline derivatives of the present invention are synthesized according to the following synthetic route.

4aa: R ¹ =Ph, R ² =Me, R ³ =H;

4ba: R ¹ =4-OMe-Ph, R ² =Me, R ³ =H;

4ca: R ¹ =4-Me-Ph, R ² =Me, R ³ =H;

4da: R ¹ =4-Cl-Ph, R ² =Me, R ³ =H;

4ea: R ¹ =4-Br-Ph, R ² =Me, R ³ =H;

4fa: R ¹ =4-F-Ph, R ² =Me, R ³ =H;

4ga: R ¹ =4-CF ₃ -Ph, R ² =Me, R ³ =H;

4ha: R ¹ =3,5-Me-Ph, R ² =Me, R ³ =H;

4ia: R ¹ =2-Me-Ph, R ² =Me, R ³ =H;

4ja: R ¹ = furan ring, R ² = Me, R ³ = H;

4ka: R ¹ =Ph, R ² =-CH ₂ -Ph, R ³ =H;

4la: R ¹ =2-Me-Ph, R ² =propargyl, R ³ =H;

4ab: R ¹ =Ph, R ² =Me, R ³ =4-OMe;

4ac: R ¹ =Ph, R ² =Me, R ³ =4-Me;

4ad: R ¹ =Ph, R ² =Me, R ³ =4-Cl;

4ae: R ¹ =Ph, R ² =Me, R ³ =4-Br;

4af: R ¹ =Ph, R ² =Me, R ³ =4-F;

4ag: R ¹ =Ph, R ² =Me, R ³ =4-CF ₃ ;

4ah: R ¹ =Ph, R ² =Me, R ³ =3-Me;

4ai: R ¹ =Ph, R ² =Me, R ³ =3,5-Me;

4aj: R ¹ =Ph, R ² =Me, R ³ =2-Br.

Take the compound alkynyl oxime (0.2mmol) of formula (II), the compound diaryliodonium salt (0.4mmol) of formula (III), KOH (0.4mmol), and copper acetate (20mol%) into a 10ml reaction tube, and add EtOAc (2.0mL), heat to 80℃ and stir to react until complete (TLC monitoring). The obtained reactant is decompressed to remove the solvent, and the residue is separated by silica gel column chromatography (petroleum ether/ethyl acetate = 50:1 to 30:1, volume ratio) to obtain the target product shown in formula (I). Different target products and their characterizations are as follows:

4aa: yellow solid, 0.058 g, 80% yield. Mp: 181-182°C; ¹ H NMR (400 MHz, CDCl ₃ ): δ9.59(s,1H),7.37(d,J＝7.2Hz,2H),7.31-7.27(m,2H),7.25-7.21(m,1H),7.12-7.08(m,3H),7.01(d,J＝7.2Hz,1H),6.96(d,J＝16.0Hz,1H),6.80- 6.77(m,1H),6.75-6.70(m,2H),6.64(d,J＝8.4Hz,1H),6.47(d,J＝15.6Hz,1H),4.39(s,1H),3.65(dd,J＝22.8Hz,J＝12.8Hz,2H); ¹³ (s,3H); ,CDCl ₃ ): δ197.6,150.1,146.5,136.1,131.3,130.7,129.7,128.6,127.9,127.9,127.5,126.7,124.6,124.1,120.0,118.0,112.5,110.7,71.2,62.4,4 9.4,39.7; HRMS(ESI)m/z calcd for C ₂₅ H ₂₃ N ₂ O[M+H] ⁺ :367.1805; found:367.1806.

4ba: yellow solid, 0.055 g, 70% yield. Mp: 159-160°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.59(s,1H),7.30-7.25(m,2H),7.13-7.10(m,3H),7.00(d,J＝7.5Hz,1H),6.88-6.82(m,3H),6.80(t,J＝8.0Hz,1H),6.74-6.69(m,2H),6.63(d,J＝ 9.0Hz, 1H), 6.33 (d, J = 15.5Hz, 1H), 4.37 (s, 1H), 3.79 (s, 3H), 3.64 (dd, J = 12.5Hz, J = 13.0Hz, 2H), 2.93 (s, 3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.6,159.5,150.2,146.6,130.9,129.7,128.9,128.5,128.4,128.1,128.0,127.6,124.7,124.1,119.9,114.0,112.4,110.7,71.2,62.4,5 5.3,49.4,39.7; HRMS(ESI)m/zcalcd for C ₂₆ H ₂₅ N ₂ O ₂ [M+H] ⁺ :397.1911; found:397.1921.

4ca: yellow solid, 0.045 g, 60% yield. Mp: 145-145°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.58 (s, 1H), 7.26 (d, J=5.5 Hz, 2H), 7.15-7.07 (m, 5H), 7.00 (d, J=7.5 Hz, 1H), 6.92 (d, J=15.5 Hz, 1H), 6.80 (t, J=7.5 Hz 1H),6.74-6.70(m,2H),6.64(d,J＝8.5Hz,1H),6.41(d,J＝15.5Hz,1H),4.37(s,1H),3.64(dd,J＝13.0Hz,J＝29.0Hz,2H),2.94(s,3H),2.32(s,3H); ¹³ C N MR(125MHz,CDCl ₃ ): δ197.6,150.1,146.6,137.9,133.3,131.2,129.7,129.5,129.3,128.6,128.0,127.6,126.7,124.7,124.1,120.0,118.0,112.4,110.9,71.2, 62.4,49.4,39.7,21.2; HRMS(ESI)m/z calcd for C ₂₆ H ₂₅ N ₂ O[M+H] ⁺ :381.1961; found:381.1962.

4da: yellow solid, 0.048g, 60% yield.Mp: 67-68℃; ¹ H NMR (500MHz, CDCl ₃ ): δ9.56 (s, 1H), 7.29-7.25 (m, 4H), 7.01 (d ,J＝8.0Hz,3H),6.91(d,J＝15.5Hz,1H),6.81(t,J＝7.5Hz,1H),6.75-6.70(m,2H),6.64(d,J＝8.0Hz ¹³ C NMR (125MHz, CDCl ₃ ): δ197.5,150.1,146.5,134.6,133.65,131.3,130.1,129.8,129.4,128.7,128.1,127.9,127.6,127.4,124.6,124.2,120.1,118.0,112.5,110. 8,71.2,62.4,49.4,39.7; HRMS(ESI)m/z calcdfor C ₂₅ H ₂₂ ClN ₂ O[M+H] ⁺ :401.1415; found:401.1412.

4ea: yellow solid, 0.044g, 50% yield.Mp: 87-88℃; ¹ H NMR (500MHz, CDCl ₃ ): δ9.56 (s, 1H), 7.42 (d, J = 8.0Hz, 2H), 7.22(d,J＝8.5Hz,2H),7.14-7.09(m,3H),7.01(d,J＝7.5Hz,1H),6.90(d,J＝16Hz,1H),6.81(t,J＝ 7.5Hz,1H),6.75-6.70(m,2H),6.64(d,J＝8.5Hz,1H),6.45(d,J＝16Hz,1H),4.37(s,1H),3.64-3.56(m ,2H),2.94(s,3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.5,150.1,146.5,135.0,131.7,131.4,130.2,129.8,128.7,128.2,127.6,127.4,124.6,124.2,121.8,120.1,118.0,112. 5,110.8,71.2,62.4, 49.3,39.7; HRMS(ESI)m/z calcd for C ₂₅ H ₂₂ BrNO ₂ [M+H] ⁺ :445.0910; found:445.0918.

4fa: yellow solid, 0.040 g, 53% yield. Mp: 142-143°C; ¹ H NMR (500 MHz, CDCl ₃ ): ¹ H NMR (500 MHz, CDCl ₃ ): δ9.55(s,1H),7.31(d,J＝7.0Hz,2H),7.26(t,J＝7.5Hz,2H),7.20-7.19(m,1H),7.19-7.17(m,2H),6.90(d,J＝15.5Hz,1H),6.77-6.72(m,1H),6.70- 6.68(m,2H),6.60-6.55(m,2H),6.39(d,J＝16.0Hz,1H),4.23(s,1H),3.55(dd,J＝13.0Hz,J＝18.0Hz,2H),2.89(s,3H); ¹³ CNMR(125MHz, CDCl ₃ ): δ197.3,158.2(d,J＝236.3Hz),146.5,146.1,146.1,136.0,131.6,130.2,128.7,128.6,128.6,128.0,127.7,127.5,126.8,126.4(d,J＝7.8Hz),1 18.2, 116.2 (d, J = 23.3Hz), 112.5, 111.6, 111.4, 111.3, 111.2, 71.9, 62.5, 49.3, 39.8; ¹⁹ F NMR (376MHz, CDCl ₃ ) δ – 124.2; HRMS (ESI) m/z calcd for C ₂₅ H ₂₂ FN ₂ O[M+H] ⁺ :385.1711; found:385.1721.

4ga: yellow solid, 0.041 g, 48% yield. Mp: 156-157°C; ¹ H NMR (500 MHz, CDCl ₃ ): ¹ H NMR (500 MHz, CDCl ₃ ): δ9.57(s,1H),7.53(d,J＝8.0Hz,2H),7.46(d,J＝8.0Hz,2H),7.15-7.09(m,3H),7.02-6.98(m,2H),6.82(t,J＝7.5Hz,1H),6.75-6.71(m,2H),6.65(d , J＝8.0Hz, 1H), 6.56 (d, J＝16.0Hz, 1H), 4.39 (s, 1H), 3.65 (dd, J＝13.0Hz, J＝23.5Hz, 2H), 2.94 (s, 3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.4,150.0,146.5,139.5,139.5,133.3,130.1(q,J＝32.6Hz),129.8,129.6,128.8,127.3,126.9,125.6(q,J＝3.5Hz),125.1(q,J＝270.0Hz),12 4.5,124.2,120.2,118.1,112.6,110.9,71.2,62.5,49.4,39.7; ¹⁹ F NMR (376MHz, CDCl ₃ )δ-62.5; HRMS (ESI) m/z calcd for C ₂₆ H ₂₂ F ₃ N ₂ O[M+H] ⁺ :435.1679; found:435.1679.

4ha: yellow solid, 0.047g, 60% yield.Mp: 179-180℃; ¹ H NMR (500MHz, CDCl ₃ ): δ9.51 (s, 1H), 7.06 (dd, J=9.0Hz, J=16.5 Hz,3H),6.93(d,J＝11.0Hz,3H),6.81(d,J＝16.0Hz,2H),6.73(t,J＝7.5Hz,1H),6.66-6.62(m,2H), 6.56(d,J＝7.5Hz,1H),6.37(d,J＝15.5Hz,1H),4.30(s 1H),3.57(dd,J＝13.0Hz,J＝25.5Hz,2H),2.86(s ,3H),2.20(s,6H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.7,150.2,146.5,138.1,138.1,136.0,131.5,130.1,129.7,129.6,128.6,128.0,127.6,124.7,124.7,124.1,120.0,11 8.0,112.4,110.6, 71.2,62.4,49.4,39.7,21.2; HRMS(ESI)m/z calcd for C ₂₇ H ₂₇ N ₂ O[M+H] ⁺ :395.2118; found:395.2102.

4ia: yellow solid, 0.047g, 62% yield.Mp: 156-157℃; ¹ H NMR (500MHz, CDCl ₃ ): δ9.61 (s, 1H), 7.34 (d, J = 6.5Hz, 1H), 7.14-7.10(m,7H),7.02(d,J＝7.0Hz,1H),6.81(t,J＝7.0Hz,1H),6.76-6.71(m,2H),6.64(d,J＝8.0Hz ,1H),6.32(d,J＝15.0Hz,1H),4.39(s,1H),3.66(dd,J＝13.0Hz,J＝34.0Hz,2H),2.94(s,3H),2.34(s ,3H); ^13C NMR (125MHz, CDCl ₃ ): δ 197.6, 150.2, 146.5, 135.7, 135.5, 132.1, 130.2, 129.7, 129.5, 128.6, 128.0, 127.8, 127.5, 126.1, 126.0, 124.7, 124.2, 120. 0,118.0,112.5,110.7, 71.4 62.2,49.4,39.8,19.9; HRMS(ESI)m/z calcd for C ₂₆ H ₂₅ N ₂ O[M+H] ⁺ :381.1961; found:381.1963.

4ja: yellow solid, 0.037 g, 52% yield. Mp: 131-132°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.58(s,1H),7.30(s,1H),7.13-7.08(m,3H),7.00-6.99(d,J＝7.0Hz,1H),6.80(t,J＝8.0Hz,1H),6.74-6.73(m,1H),6.72-6.68(m,2H),6.63(d,J＝ 8.0Hz, 1H), 6.43-6.35 (m, 2H), 6.26-6.25 (m, 1H), 4.35 (s, 1H), 3.63 (dd, J＝12.5Hz, J＝30.5Hz, 2H), 2.93 (s, 3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.6,151.8,150.1,146.6,142.3,129.7,129.2,128.6,127.7,127.6,127.5,124.7,124.2,120.0,118.0,112.4,111.4,110.8,109.0,71.0, 62.6,49.4,39.7; HRMS(ESI)m/zcalcd for C ₂₃ H ₂₁ N ₂ O ₂ [M+H] ⁺ :357.1598; found:357.1583.

4ka: yellow solid, 0.053 g, 60% yield. Mp: 145-146°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.50(s,1H),7.30(d,J＝7.5Hz,2H),7.23-7.20(m,2H),7.19-7.14(m,4H),7.06-7.02(m,4H),6.93-6.88(m,2H),6.80(d,J＝7.5Hz,1H),6.70(t,J ＝7.5Hz,1H),6.64-6.60(m,2H),6.46-6.42(m,2H),4.49(d,J＝16.5Hz,1H),4.38(d,J＝16.5Hz,2H),3.70-3.65(m,2H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.5,150.2,145.5,138.1,136.1,131.6,130.3,129.8,128.6,128.5,128.0,127.6,127.0,126.9,126.8,124.6,124.3,119.9,117.9,112.8 ,110.7,71.4,62.5,55.9,47.5; HRMS(ESI)m/z calcd for C ₃₁ H ₂₇ N ₂ O[M+H] ⁺ :443.2118; found:443.2119.

4la: yellow solid, 0.039 g, 50% yield. Mp: 156-157°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.60(s,1H),7.37-7.36(m,2H),7.32(t,J＝7.5Hz,2H),7.24-7.23(m,2H),7.17-7.10(m,3H),7.00-6.94(m,2H),6.82-6.71(m,4H),6.46(d,J＝1 6.0Hz, 1H), 4.38 (s, 1H), 4.23 (d, J = 18.0Hz, 1H), 3.97 (d, J = 18.0Hz, 1H), 3.72 (dd, J = 13.0Hz, J = 16.5Hz, 1H), 2.21 (s, 1H); ¹³ CNMR (125MHz, CDCl ₃ ): δ197.3,150.1,144.2,136.0,131.5,130.4,129.8,129.1,128.6,128.5,128.0,127.9,126.8,124.5,124.2,120.0,119.3,113.3,110.7,78.3, 72.7,71.1,62.5,47.5,41.0; HRMS(ESI)m/z calcd for C ₂₇ H ₂₃ N ₂ O[M+H] ⁺ :391.1805; found:391.1806.

4ab: yellow solid, 0.049 g, 63% yield. Mp: 167-168°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.51(s,1H),7.28(d,J＝7.5Hz,2H),7.22(t,J＝7.5Hz,2H),7.16-7.13(m,1H),7.05-7.02(m,2H),6.88(d,J＝16.0Hz,1H),6.66(t,J＝7.5Hz,1H),6.60 (d,J＝10.0Hz,1H),6.56-6.53(m,3H),6.38(d,J＝16.0Hz,1H),4.11(s,1H),3.63(s,3H),3.53(dd,J＝12.5Hz,J＝21.5Hz,2H),2.85(s,3H); ¹³ CNMR(125MHz,CDCl ₃ ): δ197.8,154.2,146.5,143.9,136.1,131.3,130.6,128.5,128.0,127.9,127.5,126.7,126.1,118.0,114.9,112.4,111.5,110.4,71.5,62.7,5 5.8,49.3; HRMS(ESI)m/z calcd for C ₂₆ H ₂₅ N ₂ O ₂ [M+H] ⁺ :397.1911; found:397.1917.

4ac: yellow solid, 0.045 g, 60% yield. Mp: 189-190°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.57(s,1H),7.36(d,J＝7.5Hz,2H),7.30(t,J＝7.0Hz,2H),7.24(d,J＝8.5Hz,1H),7.13-7.11(m,2H),6.95-6.90(m,2H),6.80(s,1H),6.74-6.71(m ,1H),6.64-6.61(m,2H),6.46(d,J＝15.5Hz,1H),4.28(s,1H),3.63(dd,J＝13.0Hz,J＝29.0Hz,2H),2.94(s,3H),2.24(s,3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.6,150.2,146.6,137.9,133.3,131.2,129.7,129.5,129.3,128.5,128.0,127.6,126.7,124.7,124.2,120.0,118.0,112.4,110.7,71.2, 62.4,49.4,39.7,21.2; HRMS(ESI)m/z calcd for C ₂₆ H ₂₅ N ₂ O[M+H] ⁺ :381.1961; found:381.1962.

4ad: yellow solid, 0.059 g, 50% yield. Mp: 67-68°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.52(s,1H),7.29(d,J＝7.0Hz,2H),7.24(t,J＝7.5Hz,2H),7.18(d,J＝6.5Hz,1H),7.10(t,J＝7.5Hz,1H),7.04(m,1H),7.00(d,J＝12.0Hz,1H),6.89-6 .82(m,2H),6.69(t,J＝7.5Hz,1H),6.59-6.55(m,2H),6.37(d,J＝15.5Hz,1H),4.31(s,1H),3.53(dd,J＝13.0Hz,J＝17.0Hz,2H),2.88(s,3H); ¹³ CNMR(125MHz, CDCl ₃ ): δ197.1,148.9,146.5,135.9,131.7,130.0,135.9,129.6,128.8,128.6,128.1,128.1,127.5,126.8,126.6,124.7,124.3,118.2,112.6,111.6 ,71.7,62.4,49.4,39.8; HRMS(ESI)m/z calcd for C ₂₅ H ₂₂ ClN ₂ O[M+H] ⁺ :401.1415; found:401.1412.

4ae: yellow solid, 0.049 g, 56% yield. Mp: 168-169°C; ¹¹ H NMR (500 MHz, CDCl ₃ ): δ9.50(s,1H),7.27(d,J＝7.0Hz,2H),7.23(t,J＝7.0Hz,2H),7.17(d,J＝6.5Hz,1H),7.11-7.05(m,2H),7.02(d,J＝6.0Hz,2H),6.84(d,J＝16.0Hz,1H),6 .67(t,J＝7.5Hz,1H),6.58(d,J＝8.5Hz,1H),6.50(d,J＝8.0Hz,1H),6.36(d,J＝15.5Hz,1H),4.32(s,1H),3.51-3.45(m,2H),2.86(s,3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.0,149.1,146.5,135.9,132.4,131.7,130.0,128.8,128.6,128.5,128.1,127.5,127.4,127.2,127.1,126.8,118.2,112.6,112.1,111.5 ,71.6,62.3,49.4,39.8; HRMS(ESI)m/z calcd for C ₂₅ H ₂₂ BrNO ₂ [M+H] ⁺ :445.0910; found:445.0918.

4af: yellow solid, 0.041 g, 54% yield. Mp: 154-155°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.53(s,1H),7.29(d,J＝7.0Hz,2H),7.24-7.21(m,2H),7.18-7.15(m,1H),7.08-7.03(m,2H),6.88(d,J＝15.5Hz,1H),6.74-6.71(m,2H),6.69-6.6 6(m,2H),6.58-6.53(m,2H),6.38(d,J＝16.0Hz,1H),4.21(s,1H),3.53(dd,J＝13.0Hz,J＝18.0Hz,1H),2.87(s,3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.3,158.8(d,J＝236.3Hz),146.7,146.1,146.1,136.0,131.6,130.2,128.7,128.6,128.0,127.7,127.5,126.8,126.4(d,J＝7.3Hz),118.2,1 16.2 (d, J=23.3Hz), 112.5, 111.6, 111.3, 111.2, 71.9, 62.5, 49.2, 39.7; ¹⁹ F NMR (376MHz, CDCl ₃ ) δ – 126.3; HRMS (ESI) m/z calcd for C ₂₅ H ₂₂ FN ₂ O [M+H] ⁺ :385.1711; found:385.1721.

4ag: yellow solid, 0.043 g, 50% yield. Mp: 178-179°C; ¹ H NMR (500 MHz, CDCl ₃ ) ¹ H NMR (500 MHz, CDCl ₃ ): δ9.57(s,1H),7.56(d,J＝8.5Hz,2H),7.46(d,J＝8.0Hz,2H),7.16-7.09(m,3H),7.02-6.99(m,2H),6.83(t,J＝7.5Hz,1H),6.76-6.72(m,2H),6.66(d , J＝8.0Hz, 1H), 6.56 (d, J＝16.0Hz, 1H), 4.40 (s, 1H), 3.66 (dd, J＝13.0Hz, J＝23.5Hz, 2H), 2.95 (s, 3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.4,150.0,146.6,139.6,139.5,133.3,130.1(q,J＝30.6Hz),129.9,129.6,128.8,127.4,127.3,126.9,125.6(q,J＝3.5Hz),125.1(q,J＝268. 0Hz),124.5,124.2,120.3,118.1,112.6,110.9,71.2,62.5,49.4,39.7; ¹⁹ F NMR (376MHz, CDCl ₃ )δ-62.5; HRMS (ESI) m/z calcd for C ₂₆ H ₂₂ F ₃ N ₂ O[M+H] ⁺ :435.1679; found:435.1679.

4ah: yellow solid, 0.049g, 65% yield.Mp: 167-168℃; ¹ H NMR (500MHz, CDCl ₃ ): δ9.58 (s, 1H), 7.26 (d, J = 7.5Hz, 2H), 7.18-7.05(m,5H),7.01(d,J＝7.5Hz,1H),6.92(d,J＝15.5Hz,1H),6.80-6.77(m,1H),6.74-6.70(m,2H) ,6.64(d,J＝8.5Hz,1H),6.41(d,J＝15.5Hz,1H),4.37(s,1H),3.64-3.56(m,2H),2.94(s,3H),2.32( s,3H); ¹³ C NMR (125MHz, CDCl ₃ ): δ197.7,150.3,146.6,135.8,135.6,132.2,130.3,129.8,129.5,128.6,128.0,127.9,127.5,126.2,126.1,124.7,124.3,120. 1,118.1,112.6,110.8, 71.5,62.3,49.4,39.8,20.0; HRMS(ESI)m/zcalcd for C ₂₆ H ₂₅ N ₂ O[M+H] ⁺ :381.1961; found:381.1956.

4ai: yellow solid, 0.050 g, 64% yield. Mp: 143-144°C; ¹ H NMR (500 MHz, CDCl ₃ ): ¹ H NMR (500 MHz, CDCl ₃ ): δ9.49(s,1H),7.35(d,J＝7.5Hz,2H),7.28-7.27(m,2H),7.23-7.20(m,1H),7.11-7.107(m,2H),6.93(d,J＝15.5Hz,1H),6.73-6.70(m,1H),6.63(d ,J＝8.5Hz,1H),6.48(d,J＝16.0Hz,1H),6.35(s,2H),4.32(s,1H),3.91(d,J＝13.0Hz,1H),3.50(d,J＝13.0Hz,1H),2.93(s,3H),2.16(s,6H); ¹³ C NMR (125MHz ,CDCl ₃ ): δ196.4,150.7,147.2,139.9,136.1,136.1,131.5,130.4,128.8,128.5,128.3,127.9,127.2,126.7,123.4,118.2,118.1,112.5,109.3,71.6, 63.0,53.4,49.2,39.7,21.3,18.2; HRMS(ESI)m/z calcdfor C ₂₇ H ₂₇ N ₂ O[M+H] ⁺ :395.2123; found:395.2123.

4aj: yellow solid, 0.030 g, 40% yield. Mp: 156-157°C; ¹ H NMR (500 MHz, CDCl ₃ ): δ9.56 (s, 1H), 7.50 (s, 1H), 7.36 (d, J=7.5 Hz, 1H), 7.27 (d, J=8.5 Hz, 1H), 7.17-7.08 (m, 4H), 7.01 (d, J=7.5 Hz, 1H), 6.90 (d, J=15.5 Hz, 1H), 6.81-6.80 (m, 1H), 6.75-6.71 (m 2H), 6.64 (d, J = 8.0Hz, 1H), 6.47 (d, J = 15.5Hz, 1H), 4.37 (s, 1H), 3.64 (dd, J = 13.0Hz, J = 24.0Hz, 2H) 2.94 (s, 3H); ¹³ CNMR (125MHz, CDCl ₃ ): δ197.5,150.1,146.6,138.3,132.3,130.9,130.0,129.9,129.6,128.8,127.6,127.5,125.5,124.7,124.3,122.9,120.2,118.2,112.8,110.9 ,71.2,62.6,49.5,39.8; HRMS(ESI)m/z calcd for C ₂₆ H ₂₂ BrN ₂ O[M+H] ⁺ :445.0910; found:445.0901.

Example 2: Synthesis of compounds 4aa, 4ba, 4ha, 4ae, 4aj

Compound 4aa: Example 1 was repeated, except that copper acetate was not added. A yellow solid product was finally obtained with a yield of 5%. The product was identified as compound 4aa by characterization of hydrogen nuclear magnetic spectrum, carbon spectrum and high-resolution mass spectrum.

Compound 4ba: Example 1 was repeated, except that cesium carbonate was used instead of potassium hydroxide. A yellow solid product was finally obtained with a yield of 68%. The product was identified as compound 4ba by characterization of hydrogen nuclear magnetic spectrum, carbon spectrum and high-resolution mass spectrum.

Compound 4ha: Example 1 was repeated, except that acetonitrile was used instead of ethyl acetate, copper trifluoromethanesulfonate was used instead of copper acetate, and triethylamine was used instead of potassium hydroxide. The reaction was changed to be carried out at 25°C until completion (about 3 hours). Finally, a yellow solid product was obtained with a yield of 38%. The product was identified as compound 4ha by characterization of H NMR, C NMR and high-resolution mass spectrometry.

Compound 4ae: Example 1 was repeated, except that dichloromethane was used instead of ethyl acetate, and ytterbium trifluoromethanesulfonate was used instead of copper acetate. Finally, a yellow solid product was obtained with a yield of 35%. The product was characterized by H NMR, C NMR and high-resolution mass spectrometry, and was confirmed to be Compound 4ae.

Compound 4aj: Example 1 was repeated, except that toluene was used instead of ethyl acetate, scandium trifluoromethanesulfonate was used instead of copper acetate, and the reaction was carried out at 40°C until completion. A yellow solid product was obtained with a yield of 25%. The product was identified as compound 4aj by characterization of H NMR, C NMR and high-resolution mass spectrometry.

Experimental Example 1: In vitro anti-inflammatory activity test of the indolo[3,2-c]quinoline derivatives of the present invention

1. MTT assay to determine the activity of RAW264.7 cells with the compound and the control drug indomethacin at a concentration of 100 μM

1. Digestion and inoculation of test cells: The test cells RAW 264.7 (mouse mononuclear macrophage leukemia cells) were cultured to the logarithmic phase, digested with 0.25% trypsin, added with culture medium containing 10% fetal bovine serum, blown evenly with a sterile plastic pipette to form a single cell suspension, and inoculated into a 96-well plate, adding 180 μL to each well. 200 μL PBS buffer was added around the 96-well plate to reduce evaporation of the culture medium.

2. Adding drugs to the cell lines: When the cells in the wells grow to about 70% of the entire well area, add 20 μL of drugs to each well, then dilute the drug concentration to 100 μM, tap gently with your hand, set up 5 replicate wells (parallel experiments), set up blank wells (no drug added) and zero wells (culture medium containing 10% fetal bovine serum) on each 96-well plate, continue to put it in the incubator, and observe the survival of the cells under a microscope.

3. Test plate: After adding drugs and continuing to culture for 48 hours, add 10μL of MTT to each well for staining, tap gently with hands, continue to culture for 4-6 hours, then discard the culture medium in the well, add 100μL of DMSO to each well, place on a micro-oscillator and shake for 10 minutes to fully dissolve the generated formazan, move to the enzyme-linked immunosorbent assay to detect the absorbance value of each well, and then use PASW software to process the data. The experimental results are shown in Table 1.

Table 1 Effects of compounds on RAW264.7 cell viability detected by MTT assay

From the test results in Table 1, it can be seen that when the concentration of the tested compound is 100 μM, the compounds containing chlorine, bromine and cinnamyl substitution have a certain inhibitory effect on cell survival. Therefore, the applicant further explored the effect of some less toxic indolo[3,2-c]quinoline derivatives on the NO release of cells induced by lipopolysaccharide.

2. Griess method to determine the inhibitory effect of some low-toxic compounds on the release of NO from mouse macrophages RAW 264.7 induced by lipopolysaccharides (LPS)

Compounds 4aa, 4ba, 4ha, 4la, 4ac, 4ae, and 4aj showed very low toxicity to mouse macrophages RAW 264.7, so the applicant further tested the experimental methods and experimental results of these compounds in inhibiting the release of NO from mouse macrophages RAW 264.7 induced by lipopolysaccharides (LPS):

1. Cell inoculation and pretreatment: RAW 264.7 cells (mouse mononuclear macrophage leukemia cells) grown to the logarithmic growth phase were inoculated in a 24-well culture plate, 400 μL per well. A control group, an LPS stress model group (1 μg/mL LPS), and experimental groups with different drug concentrations (6.25, 12.5, 25, and 50 μg/mL) were set up. The control group and the LPS stress model group were added with culture medium with a final concentration of 0.1% DMSO. The experimental group was pretreated with different concentrations of drug solutions for 1 h and then added with 1 μg/mL LPS for 24 h, and the cell supernatant was collected.

2. Determination of NO release by Griess method: Take the diluted series of concentration gradient standard reagents and the cell culture supernatant to be tested into a 96-well plate, 0.05 mL per well, and operate according to the instructions of the kit. The specific steps are as follows:

(1) Add 0.05 mL of room temperature Griess Regent 1 to each well and let stand for 10 min.

(2) Add 0.05 mL of room temperature Griess Regent 2 to each well and let stand for 10 min.

(3) Measure the absorbance at 540 nm, obtain a standard curve, and determine the NO concentration in the sample to be tested.

The test results are shown in Table 2:

The Griess method was used to detect the ability of compounds 4aa, 4ba, 4ha, 4la, 4ac, 4ae, and 4aj to inhibit LPS-induced NO release in mouse macrophages at a concentration of 6.25 μM.

Table 2 Effects of different compounds on NO release in RAW264.7 cells at the same concentration (6.25 μM)

From the test results, it can be seen that the inhibitory effect of most compounds on intracellular NO is comparable to that of the anti-inflammatory drug indomethacin. The above results further indicate that the synthesized indole[3,2-c]quinoline derivatives have potential anti-inflammatory activity.

Claims (10)

1. An indolo [3,2-c ] quinoline derivative of the structure shown in the following formula (I) or a pharmaceutically acceptable salt thereof:

wherein:

R ¹ represents furyl, thienyl or naphthyl, or represents unsubstituted, monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted phenyl, wherein the substituents are C _1～4 alkyl, C _1～4 alkoxy, C _1～4 perfluoroalkyl, cyano or halogen atom;

R ² represents a hydrogen atom, a benzyl group, an alkynyl group, a propargyl group, or an alkyl group of C _1～4;

r ³ represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group of C _1～4, an alkoxy group of C _1～4 or a perfluoroalkyl group of C _1～4.

2. The indolo [3,2-c ] quinoline derivative according to claim 1, characterized in that,

R ¹ represents an unsubstituted, monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted phenyl group, wherein the substituents are C _1～4 alkyl, C _1～4 alkoxy, C _1～4 perfluoroalkyl or halogen atom;

R ² represents a hydrogen atom, a benzyl group, an alkynyl group, a propargyl group, or an alkyl group of C _1～4;

R ³ represents a hydrogen atom, a halogen atom, an alkyl group of C _1～4, an alkoxy group of C _1～4 or a perfluoroalkyl group of C _1～4.

3. The method for synthesizing the indolo [3,2-c ] quinoline derivative according to claim 1, wherein the compound shown in the following formula (II) and the compound shown in the formula (III) are placed in an organic solvent, and a catalyst is added or not added under the condition of existence of an alkaline substance, and the reaction is carried out under the condition of heating or non-heating to prepare a crude product of a target compound;

R ¹ represents furyl, thienyl or naphthyl, or represents unsubstituted, monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted phenyl, wherein the substituents are C _1～4 alkyl, C _1～4 alkoxy, C _1～4 perfluoroalkyl, cyano or halogen atom;

R ² represents a hydrogen atom, a benzyl group, an alkynyl group, a propargyl group, or an alkyl group of C _1～4;

r ³ represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group of C _1～4, an alkoxy group of C _1～4 or a perfluoroalkyl group of C _1～4.

4. The method according to claim 3, wherein the catalyst is one or a combination of two or more selected from copper salts, ytterbium salts and scandium salts.

5. The method according to claim 3, wherein the organic solvent is one or a combination of two or more selected from benzene, toluene, cyclohexane, petroleum ether, carbon tetrachloride, tetrahydrofuran, ethyl acetate, acetonitrile, diethyl ether, dichloromethane, acetone, chloroform, n-hexane and dioxane.

6. The synthesis method according to claim 3, wherein the alkaline substance is one or a combination of two or more selected from the group consisting of tripotassium phosphate, sodium hydroxide, potassium hydroxide, calcium hydroxide, cesium carbonate, potassium tert-butoxide, sodium tert-butoxide, potassium fluoride, pyridine, triethylamine and N, N-diisopropylethylamine.

7. The method according to claim 3, wherein the reaction is carried out at a temperature of 40 ℃.

8. The method according to any one of claims 3 to 7, further comprising a step of purifying the crude target compound.

9. Use of an indolo [3,2-c ] quinoline derivative of claim 1 or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for the treatment of inflammation.

10. A pharmaceutical composition comprising as an active ingredient a therapeutically effective amount of an indolo [3,2-c ] quinoline derivative of claim 1 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.