2-methylquinoline derivatives with antitumor activity, and synthetic methods and uses thereof

Abstract

The application belongs to the field of biological medicine, and discloses a 2-methyl quinoline derivative with a structure as shown in formula I, R is selected from substituted phenyl as shown in the formula, n is an integer of 1-5, R1 is selected from C1-C3 alkyl, halogen-substituted C1-C3 alkyl, C1-C3 alkoxy, halogen-substituted C1-C3 alkoxy, 3,4-methylenedioxy, phenyl and -NR3R4; R3 and R4 are independently selected from H and C1-C3 alkyl; however, the substituted phenyl does not include p-methoxyphenyl and 3-amino-4-methoxyphenyl; X is selected from C and N, and R2 is selected from H and C1-C3 alkyl, but X cannot be selected from C and R2 cannot be selected from H at the same time. The 2-methyl quinoline derivative has good antitumor activity, and the toxicity to human normal cells is weaker than the toxicity to cancer cells. The application discloses application of the 2-methyl quinoline derivative in preparation of an antitumor drug.

Description

[0001] This application is a divisional application of the invention entitled "2-methyl quinoline derivatives with anti-tumor activity and synthetic methods and uses thereof", application number 2020105839155, filed on June 24, 2020. TECHNICAL FIELD

[0002] The present application belongs to the field of pharmaceutical chemistry, and specifically relates to a 2-methyl quinoline derivative with anti-tumor activity and a synthetic method and use thereof. BACKGROUND

[0003] Cancer is a major disease affecting human health and life, and has become one of the important public health problems in the world. According to the Global Cancer Report, in 2018, there were an estimated 1810 million new cancer cases worldwide, with 960 million deaths, and the global cancer burden further increased. Among women, breast cancer is the most common cancer and the leading cause of death from cancer. The incidence rate (24.2%, i.e. breast cancer in women accounts for 24.2% of the total cases) and mortality rate (15.0%, i.e. breast cancer deaths account for about 15.0% of all cancer deaths) of breast cancer are the highest.

[0004] The microtubulin inhibitors represented by paclitaxel are one of the most effective anti-tumor drugs, but traditional microtubulin inhibitors are often disturbed by the rapidly developing tumor multi-drug resistance, which also becomes a thorny problem in clinical treatment. In recent years, some natural small molecule microtubulin inhibitors not only show high activity, low toxicity, good bioavailability and other characteristics, but also are not the substrates of multi-drug resistance pumps, and thus are effective on multi-drug resistant tumor cells. The structural modification research on such small molecule compounds has become one of the important ways to find high-efficiency multi-drug resistance protein inhibitors and thus improve the effect of breast cancer chemotherapy.

[0005] In recent years, the anti-tumor effect of quinoline compounds has attracted people's attention. Many researchers have referred to the structural characteristics of the known microtubulin inhibitor CA-4 and synthesized compounds with good anti-tumor activity. SUMMARY

[0006] Through computer simulation, the inventors speculate that the structural basis for the combination of quinoline compounds with microtubules and the inhibition of microtubule polymerization may be: 1) quinoline alkaloid skeleton, which may be more consistent with the lumen of the microtubule target; 2) quinoline compounds have N atoms, and the sulfhydryl group in the microtubule is the hydrogen bond donor, and the N atom is the hydrogen bond acceptor, which is easy to combine. These characteristic structures may be one of the chemical structural bases for the combination of quinoline compounds with microtubules and the inhibition of microtubule polymerization.

[0007] The purpose of the present application is to provide a 2-methyl quinoline derivative as shown in formula I:

[0008]

[0009] wherein R is selected from the group consisting of substituted phenyl,

[0010] n is an integer from 1 to 5, R1 is selected from the group consisting of C1-C3 alkyl, halogen-substituted C1-C3 alkyl, C1-C3 alkoxy, halogen-substituted C1-C3 alkoxy, 3,4-methylenedioxy, phenyl, -NR3R4; R3, R4 are independently selected from H, C1-C3 alkyl; but the substituted phenyl does not include p-methoxyphenyl, 3-amino-4-methoxyphenyl;

[0011] X is selected from C, N, R2 is selected from H, C1-C3 alkyl, but not simultaneously X is selected from C, R2 is selected from H.

[0012] Preferably, n is an integer from 1 to 3, R1 is selected from the group consisting of C1-C3 alkyl, halogen-substituted C1-C3 alkyl, C1-C3 alkoxy, 3,4-methylenedioxy, phenyl, -NR3R4; R3, R4 are independently selected from C1-C3 alkyl; but the substituted phenyl does not include p-methoxyphenyl, 3-amino-4-methoxyphenyl;

[0013] X is selected from C, N, R2 is selected from H, methyl, but not simultaneously X is selected from C, R2 is selected from H.

[0014] More preferably, n is 1 or 2, R1 is selected from the group consisting of C1-C3 alkyl, C1-C3 alkoxy, 3,4-methylenedioxy, phenyl, -NR3R4; R3, R4 are independently selected from C1-C3 alkyl; but the substituted phenyl does not include p-methoxyphenyl, 3-amino-4-methoxyphenyl. When n is 1, R1 is preferably substituted at the para position; when n is 2, R1 is preferably substituted at the para and meta positions;

[0015] X is selected from C, N, R2 is selected from H, methyl, but not simultaneously X is selected from C, R2 is selected from H.

[0016] The halogen in the present application is F, Cl, Br, I.

[0017] Specifically, the 2-methylquinoline derivative in the present application is selected from the group consisting of:

[0018]

[0019]

[0020] The corresponding chemical name is:

[0021] N,2-dimethyl-N-(3,4,5-trimethoxyphenyl)quinolin-4-amine;

[0022] N,2-dimethyl-N-(3,4-dimethoxyphenyl)quinolin-4-amine;

[0023] N,2-dimethyl-N-(4-methylphenyl)quinolin-4-amine;

[0024] N,2-dimethyl-N-(3,4-methylenedioxyphenyl)quinolin-4-amine;

[0025] N,2-dimethyl-N-(4-trifluoromethylphenyl)quinolin-4-amine;

[0026] N,2-dimethyl-N-(4-biphenyl)quinolin-4-amine;

[0027] N,2-dimethyl-N-(4-dimethylaminophenyl)quinolin-4-amine;

[0028] N,2-dimethyl-N-(4-diethylaminophenyl)quinolin-4-amine;

[0029] N,2-dimethyl-N-(1-methyl-7-indol-5-yl)quinolin-4-amine;

[0030] N,2-dimethyl-N-(1,2-dimethylindol-5-yl)quinolin-4-amine.

[0031] Another object of the present application is to provide a synthesis method of the 2-methyl quinoline derivative as shown in formula I, and the reaction formula is as follows:

[0032]

[0033] comprising the following steps:

[0034] Step (1), substitution reaction: taking 2-methyl-4-chloroquinoline and substituted aniline (R-NH2) as raw materials, adding concentrated hydrochloric acid to adjust the pH of the reaction system to 5-7, and reacting at 75-85°C for 2-4h to obtain an intermediate shown in formula II;

[0035] Step (2), methylation reaction: taking the intermediate shown in formula II and sodium hydride, methyl iodide as raw materials, and taking N,N-dimethylformamide (DMF) as a reaction solvent, first reacting under ice bath conditions for 0.5-1h, and then reacting at room temperature for 1-2h; the reaction liquid is extracted with water and dichloromethane, the organic phase is suspended dry, and the 2-methyl quinoline derivative shown in formula I is obtained by column chromatography purification; wherein the molar ratio of the intermediate shown in formula II, sodium hydride and methyl iodide = 1:3:3.

[0036] In step (1), the molar ratio of 2-methyl-4-chloroquinoline and substituted aniline is 1:1-1.2, preferably 1:1.

[0037] The reaction solvent is isopropyl alcohol (IPA), a mixed solvent of ethanol and water, a mixed solvent of tetrahydrofuran and water, etc. The inventors find that the intermediate can be precipitated in isopropyl alcohol, so that the intermediate is more conveniently and efficiently obtained, and therefore, the reaction solvent is preferably isopropyl alcohol. After the reaction is completed, the reaction solution is cooled to precipitate, filtered and dried to obtain the intermediate shown in formula II.

[0038] In step (2), the molar ratio of the intermediate shown in formula II, sodium hydride and iodomethane is 1:3-4:3-4, and is preferably 1:3:3.

[0039] After the reaction is completed, the reaction solution is extracted with water and dichloromethane, the organic phase is suspended and dried, and silica gel column chromatography is used for purification with petroleum ether: ethyl acetate = 1:1 V / V as the eluent to obtain the 2-methyl quinoline derivative shown in formula I.

[0040] The inventors have verified through experiments that the 2-methyl quinoline derivative has good anti-tumor activity, and the toxicity to human normal cells is weaker than the toxicity to cancer cells. Among them, compounds I-9 and I-10 have a significant inhibitory level on the HepG2 tumor cell line, and have less toxicity, and are expected to become an anti-cancer drug with research prospects through further research. Therefore, another object of the present application is to provide the use of the 2-methyl quinoline derivative in the preparation of an anti-tumor drug.

[0041] Preferably, the tumor is liver cancer.

[0042] Advantages of the present application:

[0043] The raw materials of the 2-methyl quinoline derivative are cheap and easy to obtain, the reagents used are low in toxicity, the preparation method has mild reaction conditions, the post-treatment is convenient, and the product can be enriched in large quantities. Pharmacological experiments show that the 2-methyl quinoline derivative has good anti-tumor activity, and is expected to develop into an anti-tumor drug. DETAILED DESCRIPTION

[0044] In order to further illustrate the present application, a series of examples are listed below. These examples are illustrative and should not be construed as limiting the present application.

[0045] Example 1

[0046] Preparation of N,2-dimethyl-N-(3,4,5-trimethoxyphenyl)quinolin-4-amine (compound I-1)

[0047] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4,5-trimethoxyaniline (103 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of raw material reaction complete). The reaction is cooled to crystallize, suction filtration and drying to obtain 117 mg of intermediate. The intermediate is dissolved in N,N-dimethylformamide, 26 mg of sodium hydride, 67 μL of methyl iodide are added to the solution, first react for 1 h in an ice bath, then react for 1 h at room temperature, the reaction is extracted with water and dichloromethane, the organic phase is suspended and dried, and the final product N,2-dimethyl-N-(3,4,5-trimethoxyphenyl)quinolin-4-amine 91 mg, yield 48%, is obtained by silica gel column chromatography (eluent petroleum ether: ethyl acetate = 1:1 V / V).

[0048]

[0049] ESI-MS: 337.16 [M-H] - .

[0050] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.75 (3H, s), 3.47 (3H, s), 3.7 (6H, s), 3.83 (3H, s), 6.14 (2H, s), 7.01 (1H, s), 7.32 (1H, t), 7.61 (1H, t), 7.68 (1H, d), 8.03 (1H, d).

[0051] Example 2

[0052] Preparation of N,2-dimethyl-N-(3,4-dimethoxyphenyl)quinolin-4-amine (Compound I-2)

[0053] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4-dimethoxyaniline (86 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of raw material reaction complete). The reaction is cooled to crystallize, suction filtration and drying to obtain 120 mg of intermediate. The intermediate is dissolved in N,N-dimethylformamide, 29 mg of sodium hydride, 76 μL of methyl iodide are added to the solution, react for 1 h in an ice bath, then react for 1 h at room temperature, the reaction is extracted with water and dichloromethane, the organic phase is suspended and dried, and the final product N,2-dimethyl-N-(3,4-dimethoxyphenyl)quinolin-4-amine 94 mg, yield 54%, is obtained by silica gel column chromatography (eluent petroleum ether: ethyl acetate = 1:1 V / V).

[0054]

[0055] ESI-MS: 307.15 [M-H] - .

[0056] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.61 (3H, s), 3.39 (3H, s), 3.65 (3H, s), 3.69 (3H, s),

[0057] 6.31 (1H, d), 6.77 (2H, m), 7.06 (1H, s), 7.19 (1H, m), 7.52 (2H, m), 7.81 (1H, dd).

[0058] Example 3

[0059] Preparation of N,2-dimethyl-N-(4-methylphenyl)quinolin-4-amine (Compound I-3)

[0060] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4-dimethoxyaniline (60 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of raw materials completely reacted). The reaction solution is cooled to crystallize, suction filtration and drying to obtain 105 mg of intermediate. Dissolve the intermediate in N,N-dimethylformamide, add sodium hydride 31 mg, methyl iodide 79 μL to the solution, react for 1 h in ice bath, then react for 1 h at room temperature, extract the reaction solution with water and dichloromethane, suspend the organic phase to dryness, purify by silica gel column chromatography (eluent petroleum ether: ethyl acetate = 1:1 V / V) to obtain the final product N,2-dimethyl-N-(4-methylphenyl)quinolin-4-amine 89 mg, yield 60%.

[0061]

[0062] ESI-MS: 261.15 [M-H] - .

[0063] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.21 (3H, s), 2.61 (3H, s), 3.38 (3H, s), 6.76 (2H, dd), 7.02 (2H, dd), 7.12 (1H, s), 7.21 (1H, m), 7.53 (2H, m), 7.84 (1H, dd).

[0064] Example 4

[0065] Preparation of N,2-dimethyl-N-(3,4-methylenedioxyphenyl)quinolin-4-amine (Compound I-4)

[0066] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4-dimethoxyaniline (77 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of raw materials completely reacted). The reaction was cooled to crystallize, suction filtered and dried to obtain 110 mg of intermediate. The intermediate was dissolved in N,N-dimethylformamide, 28 mg of sodium hydride and 74 μL of methyl iodide were added to the solution, and the reaction was carried out in an ice bath for 1 h, and then at room temperature for 1 h. The reaction was extracted with water and dichloromethane, and the organic phase was suspended and dried, and purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 1:1 V / V) to obtain the final product N,2-dimethyl-N-(3,4-methylenedioxyphenyl)quinolin-4-amine 81 mg, yield 49%.

[0067]

[0068] ESI-MS: 291.12 [M-H] - .

[0069] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.61 (3H, s), 3.35 (3H, s), 5.98 (2H, s), 6.29 (1H, dd), 6.68 (1H, d), 6.75 (1H, d), 7.08 (1H, s), 7.24 (1H, m), 7.54 (2H, m), 7.83 (1H, dd).

[0070] Example 5

[0071] Preparation of N,2-dimethyl-N-(4-trifluoromethylphenyl)quinolin-4-amine (Compound I-5)

[0072] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4-dimethoxyaniline (91 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of complete reaction of starting material). Allow the reaction to cool and crystallize, filter and dry to give intermediate 137 mg. Dissolve the intermediate in N,N-dimethylformamide, add sodium hydride 33 mg, iodomethane 84 μL, react for 1 h in an ice bath, then at room temperature for 1 h, extract the reaction with water and dichloromethane, suspend the organic phase to dryness, purify by column chromatography on silica gel (eluent petroleum ether: ethyl acetate = 1 : 1 V / V) to give the final product N,2-dimethyl-N-(4-trifluoromethylphenyl)quinolin-4-amine 121 mg, yield 68%.

[0073]

[0074] ESI-MS: 315.12 [M-H] - .

[0075] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.66 (3H, s), 3.30 (3H, s), 6.77 (2H, d), 7.39 (1H, s), 7.46 (3H, m), 7.62 (1H, d), 7.70 (1H, m), 7.98 (1H, d).

[0076] Example 6

[0077] Preparation of N,2-dimethyl-N-(4-biphenyl)quinolin-4-amine (Compound I-6)

[0078] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4-dimethoxyaniline (96 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of complete reaction of starting material). Allow the reaction to cool and crystallize, filter to give intermediate 140 mg. Dissolve the intermediate in N,N-dimethylformamide, add sodium hydride 33 mg, iodomethane 84 μL, react for 1 h in an ice bath, then at room temperature for 1 h, extract the reaction with water and dichloromethane, suspend the organic phase to dryness, purify by column chromatography on silica gel (eluent petroleum ether: ethyl acetate = 1 : 1 V / V) to give the final product N,2-dimethyl-N-(4-biphenyl)quinolin-4-amine 103 mg, yield 56%.

[0079]

[0080] ESI-MS: 323.16 [M-H]- .

[0081] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.65 (3H, s), 3.47 (3H, s), 6.88 (2H, d), 7.37 (5H, m), 7.59 (6H, m), 7.92 (1H, d).

[0082] Example 7

[0083] Preparation of N,2-dimethyl-N-(4-diethylaminophenyl)quinolin-4-amine (Compound I-8)

[0084] Dissolve 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 3,4-dimethoxyaniline (77 mg, 0.565 mmol) in isopropanol, adjust pH to 6 by adding concentrated hydrochloric acid, heat to reflux for 2 h (TLC detection of complete reaction of starting material). The reaction solution is cooled to precipitate, filtered and dried to give 102 mg of intermediate. Dissolve the intermediate in N,N-dimethylformamide, add sodium hydride 26 mg, methyl iodide 69 μL to the solution, react for 1 h in ice bath, then at room temperature for 1 h, extract the reaction solution with water and dichloromethane, suspend the organic phase to dryness, purify by silica gel column chromatography (eluent petroleum ether: ethyl acetate = 1:1 V / V) to give the final product N,2-dimethyl-N-(4-diethylaminophenyl)quinolin-4-amine 64 mg, yield 39%.

[0085]

[0086] ESI-MS: 290.17 [M-H] - .

[0087] 1 H-NMR (300 MHz, DMSO-d6, TMS), δ H : 2.60 (3H, s), 2.84 (6H, s), 3.32 (3H, s), 6.65 (2H, d), 6.86 (2H, d), 6.98 (1H, s), 7.12 (1H, t), 7.48 (2H, m), 7.77 (1H, d).

[0088] Example 8

[0089] Preparation of N,2-dimethyl-N-(4-diethylaminophenyl)quinolin-4-amine (Compound I-8)

[0090] To 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 4-diethylaminoaniline (93 mg, 0.565 mmol) dissolved in isopropanol, add concentrated hydrochloric acid to adjust pH to 6, heat to reflux for 2 h (TLC detection of complete reaction of starting material). Allow the reaction to cool and crystallize, suction filter to obtain 138 mg of intermediate. Dissolve the intermediate in N,N-dimethylformamide, add sodium hydride 33 mg, iodomethane 84 μL, react for 1 h in an ice bath, then at room temperature for 1 h, extract the reaction with water and dichloromethane, suspend the organic phase to dryness, purify by silica gel column chromatography (eluent petroleum ether: ethyl acetate = 1 : 1 V / V) to obtain the final product N,2-dimethyl-N-(4-diethylamino- phenyl)quinolin-4-amine 43 mg, yield 24%.

[0091]

[0092] ESI-MS: 318.20 [M-H] - .

[0093] 1H-NMR (300 MHz, DMSO-d6, TMS), δ ppm 1.05 (6H, t), 2.60 (3H, s), 3.29 (7H, m), 6.59 (2H, m), 6.84 (2H, m), 7.12 (1H, m), 7.49 (2H, m), 7.77 (1H, d).

[0094] Example 9

[0095] Preparation of N,2-dimethyl-N-(1-methyl-7-N-hydroindol-5-yl)quinolin-4-amine (Compound I-9)

[0096] To 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 5-amino 7-N- hydroindole (75 mg, 0.565 mmol) dissolved in isopropanol, add concentrated hydrochloric acid to adjust pH to 6, heat to reflux for 2 h (TLC detection of complete reaction of starting material). Allow the reaction to cool and crystallize, suction filter to obtain 132 mg of intermediate. Dissolve the intermediate in N,N-dimethylformamide, add sodium hydride 35 mg, iodomethane 90 μL, react for 1 h in an ice bath, then at room temperature for 1 h, extract the reaction with water and dichloromethane, suspend the organic phase to dryness, purify by silica gel column chromatography (eluent petroleum ether: ethyl acetate = 1 : 1 V / V) to obtain the final product N,2-dimethyl-N-(1-methyl-7-N-hydroindol-5-yl)quinolin-4-amine 29 mg, yield 17%.

[0097]

[0098] ESI-MS: 301.15 [M-H] -.

[0099] 1H-NMR(300MHz,DMSO-d6,TMS),δppm:2.74(3H,s),3.51(3H,s),3.89(3H,s),6.32(1H,d), 6.95(1H,s),7.12(1H,t),7.18(1H,d),7.51(2H,m),7.59(1H,d),7.96(1H,d),8.20(1H,d).

[0100] Example 10

[0101] Preparation of N,2-dimethyl-N-(1,2-dimethylindol-5-yl)quinoline-4-amine (compound I-10)

[0102] Take 2-methyl-4-chloroquinoline (100 mg, 0.565 mmol) and 2-methyl-5-aminoindole (83 mg,

[0103] 0.565 mmol) was dissolved in isopropanol, and the pH was adjusted to 6 with concentrated hydrochloric acid. The mixture was heated under reflux for 2 h (TLC showed the reaction was complete). The reaction solution was cooled to crystallize, and 127 mg of intermediate was obtained by filtration. The intermediate was dissolved in N,N-dimethylformamide, and 32 mg of sodium hydroxide and 82 μL of iodomethane were added to the solution. The mixture was reacted in an ice bath for 1 h, and then at room temperature for 1 h. The reaction solution was extracted with water and dichloromethane, and the organic phase was suspended to dryness. The solution was purified by silica gel column chromatography (eluting buffer: petroleum ether: ethyl acetate = 1:1 V / V) to give 28 mg of the final product N,2-dimethyl-N-(1,2-dimethylindol-5-yl)quinoline-4-amine, with a yield of 16%.

[0104]

[0105] ESI-MS: 314.17 [MH] - .

[0106] 1H-NMR(300MHz,DMSO-d6,TMS),δppm:2.35(3H,s),2.62(3H,s),3.40(3H,s),3.62(3H ,s),6.07(1H,s),6.84(1H,dd),7.02(3H,m),7.28(1H,m),7.43(2H,dd),7.75(1H,m).

[0107] Example 11

[0108] Pharmacological experiments of 2-methylquinoline derivatives

[0109] The 2-methyl quinoline derivatives are subjected to anti-tumor activity test by using the tetramethyl benzothiazole blue colorimetric method (MTT method), and combretastin (CA-4) is selected as a positive control drug.

[0110] Instruments: super-clean bench (SW-CJ-1FD, AIRTECH, Suqing Antai), constant-temperature CO2 incubator (3111, Thermo, USA), inverted biological microscope (IX71, OLYMPUS, Japan), enzyme-linked immunoassay instrument (Model 680, BIO-RAD, USA), plate shaker (Kylin-bell lab Instruments), high-pressure sterilization pot (YXO.SG41.280, Shanghai Huaxian), centrifuge (SIGMA).

[0111] Reagents: DMEM medium (GIBCO), fetal bovine serum (GIBCO), trypsin (SIGMA), DMSO (SIGMA).

[0112] Cell strains: human hepatoma cell strain HepG2 and human normal liver cell strain L-02 (both provided by Jiangsu Keygen Biotech Co., Ltd.).

[0113] Method: the frozen cell strains are recovered by using DMEM medium, and are placed in a constant-temperature 37℃ CO2 incubator for culture, and the liquid is replaced once a day; when the cell strains are in a good exponential growth phase, they are plated. 1mL of 0.25% trypsin digestion solution is added, and the cells are digested for 1-2min; under a microscope, when the adherent cells are round and shrink, the digestion solution is removed, 1-2mL of DMEM medium containing 10% fetal bovine serum is added to prepare a cell suspension, and the cell suspension is counted; the amount of cell suspension required is calculated according to the number of cells per hole (5x10 4 The cell suspension is inoculated on a 96-well plate at 100μL / hole, and the periphery is sealed with PBS solution; the plate is placed in a constant-temperature 37℃ CO2 incubator for culture for 24h.

[0114] The test drugs and the positive control combretastin (CA-4) are prepared by using DMEM medium, so that the final concentration is 1μM / hole; DMSO is used as a blank control (DMSO is diluted with the medium); each drug has 3 replicate holes, and the culture is carried out for 48h. MTT reagent (concentration: 5mg / mL, prepared by using PBS) is added to the 96-well plate at 10μL / hole, and the incubation is continued for 4h. The culture medium in the plate is removed, 100μL of DMSO is added to each hole, and the plate shaker is shaken for 10min to dissolve the crystals. The enzyme-linked immunoassay instrument is used to detect the absorbance value of each hole at a wavelength of 570nm, and the cell inhibition rate is calculated. The average value of three primary screening results is the final inhibition rate, and the compounds with a primary screening inhibition rate greater than 50% are subjected to concentration gradient screening (5-fold dilution) to calculate the IC 50The final IC50value of the tested compound was calculated from the average of three repeated experiments (Graphpad software calculation). 50 The final IC50value of the tested compound was calculated from the average of three repeated experiments (Graphpad software calculation).

[0115] Cell inhibition rate % = [(blank control OD value - drug group OD value) / blank control group OD value] x 100%

[0116] Results: 2-methylquinoline derivatives have inhibitory effect on human hepatoma cell line HepG2, but the inhibition rate of tested compounds I-1, I-5 is less than 50% (1 μM concentration, the inhibition rate of compound I-1 on HepG2 is 10%; the inhibition rate of compound I-5 on HepG2 is 16%), therefore, the IC50values of tested compounds I-2, I-3, I-4, I-6, I-7, I-8, I-9, I-10 are 0.0025 ± 0.0001, 0.0021 ± 0.0001, 0.0023 ± 0.0001, 0.0023 ± 0.0001, 0.0023 ± 0.0001, 0.0023 ± 0.0001, 0.0023 ± 0.0001, 0.0021 ± 0.0001 μM respectively. 50 .

[0117] Table 1. Inhibitory effect of tested compounds on HepG2 cell line

[0118]

[0119] From Table 1, it can be seen that compounds I-2, I-3, I-4, I-6, I-7, I-8, I-9, I-10 have obvious inhibitory effect on HepG2 cells, among which compounds I-9, I-10 have the best activity, and the IC50values are 0.0025 ± 0.0001, 0.0021 ± 0.0001 μM respectively. 50

[0120] Table 2. Inhibitory effect of tested compounds on L-02 cell line

[0121]

[0122] From Table 2, it can be seen that the toxicity of 2-methylquinoline derivatives on human normal hepatocyte cell line L-02 is weaker than that on cancer cells, among which compound I-2 has the best selectivity for hepatoma cells, and the SI value (SI value = IC 50 L-02 / IC 50 HepG2) is 80.

[0123] In summary, 2-methylquinoline derivatives have strong inhibitory effect on human lung cancer cell line HepG2. Compound I-10 has the best activity, and the IC50value on HepG2 cell line is 0.0021 ± 0.0001 μM. Compound I-2 has the best selectivity, and the IC50value on HepG2 is 0.027 ± 0.005 μM, and the IC50value on L-02 is 0.0023 ± 0.0001 μM. 50 50 50 ​​​The value is 2.172±0.680 μM, SI value is 80, and it is expected to become a new anti-tumor drug and is worth in-depth study.

Claims

1. A 2-methyl quinoline derivative as shown in formula I: wherein R is selected from 2. The method of synthesis of 2-methylquinoline derivatives according to claim 1, characterized in that comprising the following steps: Step (1), substitution reaction: using 2-methyl-4-chloroquinoline and substituted aniline as shown in formula R-NH2 as raw materials, adding concentrated hydrochloric acid to adjust the pH of the reaction system to 5-7, reacting at 75-85°C for 2-4h to obtain an intermediate shown in formula II; Step (2), methylation reaction: using the intermediate shown in formula II and sodium hydride, methyl iodide as raw materials, using N,N-dimethylformamide as the reaction solvent, first reacting under ice bath conditions for 0.5-1h, then reacting at room temperature for 1-2h to obtain the 2-methyl quinoline derivative shown in formula I.

3. The method for synthesizing 2-methylquinoline derivatives according to claim 2, characterized in that... In step (1), the molar ratio of 2-methyl-4-chloroquinoline to substituted aniline is 1:1-1.

2.

4. The method for synthesizing 2-methylquinoline derivatives according to claim 2, characterized in that... In step (1), the reaction solvent is a mixed solvent of isopropyl alcohol, ethanol and water, a mixed solvent of tetrahydrofuran and water.

5. The method of synthesis of 2-methylquinoline derivatives according to claim 4, characterized in that In step (1), the reaction solvent is isopropyl alcohol.

6. The method of synthesis of 2-methylquinoline derivatives according to claim 2, wherein In step (2), the molar ratio of the intermediate shown in formula II, sodium hydride and methyl iodide is 1:3-4:3-4.

7. The method for synthesizing 2-methylquinoline derivatives according to claim 2, characterized in that... In step (2), the reaction solution is extracted with water and dichloromethane, the organic phase is rotary dried, and silica gel column chromatography is used to purify to obtain the 2-methyl quinoline derivative shown in formula I using petroleum ether: ethyl acetate = 1:1 V / V as the eluent.

8. Use of the 2-methyl quinoline derivative of claim 1 in the preparation of an antitumor drug.

Images