Preparation method of dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole bromine salt derivative

Abstract

The invention discloses a preparation method of a dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole bromine salt derivative, which comprises the following steps: mixing dehydroepiandrosterone, chloroacetyl chloride, an organic solvent and an activating-acid-binding agent, and carrying out acetylation reaction to generate dehydroepiandrosterone-3beta-ester; mixing the dehydroepiandrosterone-3beta-ester, 5, 6-dimethyl benzimidazole and methylbenzene, and then carrying out a substitution reaction, so as to obtain the dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole, namely the dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole. And mixing the dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole, alkyl bromide and toluene, and then carrying out a salt forming reaction, so as to obtain the dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole bromine salt derivative, namely the dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole bromine salt derivative. The dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole bromine salt derivative obtained by the method has remarkable in-vitro tumor growth inhibition activity on human cancer cells, and the in-vitro tumor growth inhibition activity of the dehydroepiandrosterone-3beta-ester-5, 6-dimethyl benzimidazole bromine salt derivative is superior to that of an anti-cancer drug-cis-platinum (DDP); meanwhile, the preparation method provided by the invention is simple and convenient to operate and easy to implement.

Description

Technical Field

[0001] The invention relates to the technical field of medicine and preparation and application thereof, and in particular to a method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative. Background Art

[0002] Cancer, as the second most common cause of death in the world, poses a serious threat to human health. Chemotherapy is currently one of the main methods for treating cancer. Many chemotherapeutic drugs used in clinical practice are non-selective and can cause nausea, vomiting, leukopenia, bone marrow suppression and other toxic side effects. Therefore, the development of new anti-tumor drugs with precise therapeutic properties and few or no toxic side effects has important theoretical significance and practical value. Natural products are an important component of modern medicine and the source of new drug discovery. It is an effective way to obtain drug candidate molecules to find physiologically active compounds from natural products, design and synthesize natural product libraries based on their pharmacophore information, and screen and discover high-efficiency, high-selectivity, low-toxicity lead compounds for preclinical drug research.

[0003] Compounds with 5,6-dimethylbenzimidazole structural units and dehydroepiandrosterone skeletons are widely present in natural products and synthetic drug molecules, and are important structural units of many active natural products. Studies have shown that they have a wide range of pharmacological activities, such as antibacterial, anti-inflammatory, anti-tuberculosis, anti-arrhythmic, and especially anti-tumor activities. Such compounds play an important role in drug research and development. However, not all compounds with 5,6-dimethylbenzimidazole structural units and dehydroepiandrosterone skeletons have pharmacological activity. The existing compounds with pharmacological activity and containing 5,6-dimethylbenzimidazole structural units and dehydroepiandrosterone skeletons are very limited. It is of great significance and value to develop more new molecules with good anti-tumor activity. Summary of the invention

[0004] In order to develop new molecules with good anti-tumor activity, the present invention provides a method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative.

[0005] The technical scheme is as follows: A method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative, the structural formula of which is shown in Formula I:

[0006]

[0007] Wherein, in Formula I, R is 4-methylbenzyl, 2-cyanobenzyl, 4-bromobenzyl, phenacyl, 4-methoxyphenacyl or 4-bromophenacyl, and the structural formula is as follows:

[0008]

[0009] Preferably, the reaction route of the preparation method is as follows:

[0010]

[0011] The method comprises the following steps:

[0012] S1: mixing dehydroepiandrosterone, chloroacetyl chloride, an organic solvent and an activating-acid-binding agent and performing an acetylation reaction to generate dehydroepiandrosterone-3β-ester;

[0013] S2: mixing the dehydroepiandrosterone-3β-ester, 5,6-dimethylbenzimidazole and toluene and performing a substitution reaction to obtain dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole;

[0014] S3: mixing the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole, bromoalkane and toluene and performing a salt-forming reaction to obtain a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative.

[0015] Preferably, the molar ratio of dehydroepiandrosterone, chloroacetyl chloride and activation-acid binding agent in S1 is 1:(1-2):(1-2);

[0016] The ratio of the mass of the dehydroepiandrosterone to the volume of the organic solvent is 1 g: (10-20) mL.

[0017] Preferably, the molar ratio of dehydroepiandrosterone-3β-ester to 5,6-dimethylbenzimidazole in S2 is 1:(2.5-3.5);

[0018] The ratio of the mass of the dehydroepiandrosterone-3β-ester to the volume of toluene is 1 g: (10-20) mL.

[0019] Preferably, the molar ratio of dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole to the bromide in S3 is 1:(1.5-2.5);

[0020] The ratio of the mass of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole to the volume of toluene is 1 g: (50-150) mL.

[0021] Preferably, the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative is used in the preparation of anti-tumor drugs.

[0022] The beneficial effects of the present invention are:

[0023] The invention provides a method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative, which can be used for preparing anti-tumor drugs and has good pharmacological activity; the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative obtained by the method has significant in vitro tumor growth inhibition activity on human cancer cells (breast cancer, liver cancer, prostate cancer cells), and its in vitro tumor growth inhibition activity is better than that of the anticancer drug cisplatin (DDP); at the same time, the preparation method provided by the application is simple to operate and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The synthetic route of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative of the present invention;

[0025] Figure 2 A reaction route for the acetylation reaction to produce dehydroepiandrosterone-3β-ester;

[0026] Figure 3 The reaction route for the substitution reaction to generate dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole;

[0027] Figure 4 A reaction scheme for the salt-forming reaction to generate dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazolium bromide derivatives;

[0028] Figure 5 The hydrogen nuclear magnetic resonance spectrum of the compound of Example 1 is schematically shown;

[0029] Figure 6 The carbon NMR spectrum of the compound of Example 1 is schematically shown;

[0030] Figure 7 The hydrogen nuclear magnetic resonance spectrum of the compound of Example 2 is schematically shown;

[0031] Figure 8 The carbon NMR spectrum of the compound of Example 2 is schematically shown;

[0032] Fig. 9 The hydrogen nuclear magnetic resonance spectrum of the compound of Example 3 is schematically shown;

[0033] Fig.10 The carbon NMR spectrum of the compound of Example 3 is schematically shown;

[0034] Fig.11 The hydrogen nuclear magnetic resonance spectrum of the compound of Example 4 is schematically shown;

[0035] Fig.12 The carbon NMR spectrum of the compound of Example 4 is schematically shown;

[0036] Fig.13 The hydrogen nuclear magnetic resonance spectrum of the compound of Example 5 is schematically shown;

[0037] Fig.14 The carbon NMR spectrum of the compound of Example 5 is schematically shown;

[0038] Fig.15 The hydrogen nuclear magnetic resonance spectrum of the compound of Example 6 is schematically shown;

[0039] Fig.16 The carbon NMR spectrum of the compound of Example 6 is schematically shown;

[0040] in, Figure 1 In: i) chloroacetyl chloride, dichloromethane, triethylamine, 0°C; ii) 5,6-dimethylbenzimidazole, toluene, 110°C; iii) bromoalkane, toluene, 110°C. DETAILED DESCRIPTION

[0041] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0042] It should be noted that, see Figure 1 As shown, the process, conditions, reagents, experimental methods, etc. for implementing the present invention, except for the contents specifically mentioned below, are all common knowledge and common common sense in the art, and the present invention has no particular restrictions. In the following examples, the structures of the compounds are determined by nuclear magnetic resonance, and the known starting materials of the present invention can be synthesized by methods known in the art or can be purchased from commercial reagent platforms.

[0043] The present invention provides a method for preparing the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative, comprising the following steps:

[0044] See also Figure 2 As shown, S1: dehydroepiandrosterone, chloroacetyl chloride, an organic solvent and an activating-acid-binding agent are mixed and then subjected to an acetylation reaction to generate dehydroepiandrosterone-3β-ester;

[0045] See also Figure 3 As shown, S2: the dehydroepiandrosterone-3β-ester, 5,6-dimethylbenzimidazole and toluene are mixed and subjected to a substitution reaction to obtain dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole;

[0046] See also Figure 4 As shown, S3: the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole, bromoalkane and toluene are mixed and subjected to a salt-forming reaction to obtain a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative.

[0047] It should be noted that, in the present invention, dehydroepiandrosterone, chloroacetyl chloride, an organic solvent and an activating-acid-binding agent are mixed and then subjected to an acetylation reaction to generate dehydroepiandrosterone-3β-ester. In the present invention, dehydroepiandrosterone is preferably dissolved in an organic solvent to obtain a dehydroepiandrosterone solution; an activating-acid-binding agent is added to the dehydroepiandrosterone solution to obtain; and chloroacetyl chloride is slowly added to the mixed solution under ice bath conditions.

[0048] It should be noted that, in the present invention, the organic solvent is preferably dichloromethane and / or N,N-dimethylformamide (DMF); the activation-acid binding agent is preferably one or more of triethylamine, imidazole and pyridine, more preferably triethylamine.

[0049] It should be noted that, in the present invention, the acetylation reaction is carried out at room temperature, and the time of the acetylation reaction is preferably 5 to 10 hours, and more preferably 7 to 8 hours. In the present invention, since the acetylation reaction is an exothermic reaction, the slow addition under the ice bath condition can prevent the two raw materials, dehydroepiandrosterone and chloroacetyl chloride, from mixing and contacting quickly and causing excessive reaction.

[0050] It should be noted that in the present invention, the molar ratio of dehydroepiandrosterone, chloroacetyl chloride and activation-acid binding agent in S1 is preferably 1:(1-2):(1-2), more preferably

[0051] 1:(1.5-1.7):(1.5-1.7); the ratio of the mass of dehydroepiandrosterone to the volume of the organic solvent is preferably 1 g:(10-20) mL, more preferably 1 g:(10-12) mL.

[0052] After the acetylation reaction has been carried out for a certain period of time, the organic solvent is preferably removed by distillation under reduced pressure.

[0053] It should be noted that, in the present invention, the system after reduced pressure distillation is preferably subjected to silica gel column chromatography to obtain pure dehydroepiandrosterone-3β-ester. In the present invention, the silica gel column can be a commercially available silica gel column well known to those skilled in the art, and the chromatography liquid is preferably petroleum ether and ethyl acetate; the volume ratio of petroleum ether to ethyl acetate is preferably (5-15):1, more preferably 10:1.

[0054] After obtaining dehydroepiandrosterone-3β-ester, the dehydroepiandrosterone-3β-ester, 5,6-dimethylbenzimidazole and toluene are mixed to carry out a substitution reaction. In the present invention, dehydroepiandrosterone-3β-ester is preferably dissolved in toluene to obtain a dehydroepiandrosterone-3β-ester solution; and then 5,6-dimethylbenzimidazole is added to the dehydroepiandrosterone-3β-ester solution.

[0055] The molar ratio of dehydroepiandrosterone-3β-ester to 5,6-dimethylbenzimidazole in S2 is 1:(2.5-3.5), more preferably 1:(3.0-3.2); the ratio of the mass of dehydroepiandrosterone-3β-ester to the volume of toluene is 1 g:(10-20) mL, more preferably 1 g:(10-12) mL.

[0056] It should be noted that, in the present invention, the S2 substitution reaction is preferably carried out under heating reflux conditions, and the temperature is preferably 90-110° C., more preferably 100° C.; the time of the substitution reaction in step S2 is preferably 15-20 h, more preferably 14-16 h.

[0057] After the substitution reaction has been carried out for a certain period of time, the organic solvent is preferably removed by distillation under reduced pressure.

[0058] It should be noted that the system after reduced pressure distillation is separated and purified by silica gel column chromatography. In the present invention, the silica gel column can be a commercially available silica gel column well known to those skilled in the art, and the chromatography liquid preferably contains ethyl acetate and triethylamine; the volume of the triethylamine accounts for 1% of the total volume of ethyl acetate.

[0059] After obtaining dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole, the present invention mixes the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole, bromoalkane and toluene and then performs a salt-forming reaction to obtain a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative. In the present invention, the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole is preferably first dissolved in toluene and then mixed with bromoalkane; the bromoalkane is R-Br, and the R is R in formula I, which will not be repeated here.

[0060] The molar ratio of dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole and bromoalkane in S3 is preferably 1:(1.5-2.5), more preferably 1:(2-2.2); the volume ratio of dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole and toluene is preferably 1g:(50-150)mL, more preferably 1g:(100-110)mL.

[0061] It should be noted that, in the present invention, the salt-forming reaction in S3 is independently carried out under heating reflux conditions, and the temperature of the salt-forming reaction is preferably 90-110°C, more preferably 100°C; the time of the salt-forming reaction is preferably 24-48h, more preferably 30-40h.

[0062] After the salt-forming reaction in S3 is completed, the product system is preferably naturally cooled to room temperature in the present invention, solid precipitation is precipitated, and the precipitate is washed with ethyl acetate after filtering, and then dried to obtain a pure dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative.

[0063] It should be noted that the present invention also provides the use of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative in the preparation of anti-tumor drugs. Specifically, the drug can be used to treat breast cancer, liver cancer and prostate cancer.

[0064] See also Figures 1 to 4 As shown, the preparation method of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative provided by the present invention is described in detail below in conjunction with the examples:

[0065] (1) Using dehydroepiandrosterone as raw material, synthesizing dehydroepiandrosterone-3β-ester:

[0066] Dehydroepiandrosterone was dissolved in dichloromethane, triethylamine was added, and chloroacetyl chloride was slowly added in an ice bath, with a molar ratio of raw material / triethylamine / chloroacetyl chloride = 1 / 1.5 / 1.5, and the amount of dichloromethane was 10 mL / g raw material. After the reaction system was stirred at room temperature for 8 hours, the solvent was removed by distillation under reduced pressure, and dehydroepiandrosterone-3β-ester was obtained by silica gel column chromatography (petroleum ether: ethyl acetate = 10:1);

[0067] (2) Dehydroepiandrosterone-3β-ester was used as raw material to synthesize dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole:

[0068] Dissolve dehydroepiandrosterone-3β-ester in toluene, add imidazole, the molar ratio of raw material / 5,6-dimethylbenzimidazole=1 / 3, the amount of toluene is 10mL / g raw material, heat under reflux and stir for 15 hours at 100°C, cool to room temperature, remove the solvent by reduced pressure distillation, and separate and precipitate the system after reduced pressure distillation by silica gel column chromatography, the chromatographic solution preferably contains ethyl acetate and triethylamine, the volume of the triethylamine accounts for 1% of the total volume of ethyl acetate, to obtain dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole;

[0069] (3) Using dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole as raw material, synthesize dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative:

[0070] Dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole is dissolved in toluene solvent, and bromoalkane is added under stirring, with the molar ratio of raw material / bromoalkane=1 / 2, and the amount of toluene is 100 mL / g raw material. The reaction is stirred and refluxed at 100° C. for 30 hours, and the mixture is cooled to room temperature. Solid precipitates are precipitated, filtered, and the precipitate is washed several times with ethyl acetate (50 mL / g), and dried to prepare the corresponding dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative.

[0071] Example 1

[0072] According to the preparation methods (1), (2) and (3) of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivatives proposed in the implementation method, the bromoalkane in step (3) is 4-methylbenzyl bromide, a white solid, with a yield of 92%, and the compound structure is as follows:

[0073]

[0074] Characterization Spectrum Reference Figure 5 , Figure 6 As shown: 1 H NMR (400MHz, DMSO-d6) δ9.79 (s, 1H), 7.85 (d, J = 5.2Hz, 2H), 7.39 (d, J = 8.0Hz, 2H), 7. 22(d,J=7.8Hz,2H),5.75(s,2H),5.55(s,2H),5.40(d,J=4.8Hz,1H),4.99-4.49(m,1H ),2.45-2.32(m,9H),2.31-2.22(m,3H),2.12-1.93(m,2H),1.92-1.76(m,3H),1.75-1 .53(m,5H),1.54-1.35(m,2H),1.33-1.03(m,3H),1.02-0.91(m,4H),0.80(s,3H)ppm.

[0075] 13C NMR(100MHz,DMSO-d6)δ219.65,166.09,142.13,139.22,138.23,136.77, 136.57,130.98,130.15,129.57,128.89,128.25,122.17,113.45,113.34 ,75.53,50.77,49.59,49.48,47.53,46.81,37.50,36.25,36.21,35.29,3 1.12,30.85,30.20,27.24,21.42,20.73,20.04,19.90,18.97,13.19ppm.

[0076] Example 2

[0077] According to the preparation methods (1), (2) and (3) of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivatives proposed in the implementation method, the bromoalkane in step (3) is 2-cyanobenzyl bromide, a white solid, with a yield of 90%, and the compound structure is as follows:

[0078]

[0079] Characterization Spectrum Reference Figure 7 , Figure 8 As shown: 1 H NMR (400MHz, DMSO-d6) δ9.71 (s, 1H), 8.01 (d, J = 7.6Hz, 1H), 7.91 (s, 1H), 7.80 (s, 1H), 7. 67(dt,2H),7.32(d,J=7.6Hz,1H),6.07(s,2H),5.59(s,2H),5.40(d,J=4.8Hz,1H),4.66 -4.54(m,1H),2.45-2.33(m,9H),2.11-1.93(m,2H),1.91-1.78(m,3H),1.71-1.55(m,5H ),1.53-1.33(m,2H),1.28-1.03(m,3H),1.01(s,3H),0.99-0.92(m,1H),0.80(s,3H)ppm.

[0080] 13C NMR(100MHz,DMSO-d6)δ219.64,165.94,142.86,139.23,137.06,137.01,136 .91,134.06,133.85,130.07,129.61,129.21,128.51,122.17,116.90,113.64 ,113.16,110.94,75.55,50.77,49.48,48.27,47.67,46.81,37.49,36.25,36. 22,35.30,31.12,30.85,30.20,27.22,21.43,20.06,19.90,18.98,13.19ppm.

[0081] Example 3

[0082] According to the preparation methods (1), (2) and (3) of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivatives proposed in the implementation method, the bromoalkane in step (3) is 4-bromobenzyl bromide, a white solid, with a yield of 94%, and the compound structure is as follows:

[0083]

[0084] Characterization Spectrum Reference Fig. 9 , Fig.10 As shown: 1 H NMR (400MHz, DMSO-d6) δ9.77 (s, 1H), 7.85 (d, J = 11.6Hz, 2H), 7.53 (dd, J = 67.2 ,6.4Hz,4H),5.80(s,2H),5.55(s,2H),5.40(s,1H),4.66-4.53(m,1H),2.42-2 .31(m,9H),2.12-1.94(m,2H),1.92-1.79(m,3H),1.71-1.55(m,5H),1.53-1. 37(m,2H),1.29-1.05(m,3H),1.01(s,3H),0.99-0.92(m,1H),0.80(s,3H)ppm.

[0085] 13C NMR(100MHz,DMSO-d6)δ219.65,166.06,142.33,139.22,136.86,136.70,133.41,131.98,130.51,130.14,128.87,122.17,113.53,113.26 ,75.55,50.77,49.48,49.09,47.57,46.81,37.50,36.25,36.21,35.3 0,31.12,30.85,30.20,27.24,21.43,20.04,19.90,18.97,13.19ppm.

[0086] Example 4

[0087] According to the preparation methods (1), (2) and (3) of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivatives proposed in the implementation method, the brominated alkane in step (3) is 2-bromo-1-phenylethanone, a white solid, with a yield of 93%. The compound structure is as follows:

[0088]

[0089] Characterization Spectrum Reference Fig.11 , Fig.12 As shown: 1 H NMR(400MHz, DMSO-d6)δ9.60(s,1H),8.13(d,J=7.2Hz,2H),7.89(d,J=7.2Hz,2H),7.80(t ,J=6.0Hz,1H),7.67(t,J=7.6Hz,2H),6.46(s,2H),5.67(s,2H),5.41(d,J=5.0Hz,1H),4. 69-4.57(m,1H),2.46-2.30(m,9H),2.12-1.94(m,2H),1.93-1.77(m,3H),1.75-1.54(m,5 H),1.54-1.34(m,2H),1.34-1.07(m,3H),1.03(s,3H),1.01-0.92(m,1H),0.80(s,3H)ppm.

[0090] 13C NMR(100MHz,DMSO-d6)δ219.64,191.10,166.08,143.17,139.26,136.61,1 36.58,134.57,133.77,130.05,129.66,129.05,128.44,122.17,113.47,11 3.31,75.55,53.41,50.77,49.49,47.64,46.82,37.52,36.27,36.23,35.30 ,31.12,30.86,30.20,27.25,21.43,20.05,19.97,19.91,18.98,13.19ppm.

[0091] Example 5

[0092] According to the preparation methods (1), (2) and (3) of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivatives proposed in the implementation method, the brominated alkane in step (3) is 2-bromo-4'-methoxyacetophenone, a white solid, with a yield of 90%, and the compound structure is as follows:

[0093]

[0094] Characterization Spectrum Reference Fig.13 , Fig.14 As shown: 1 H NMR (400MHz, DMSO-d6) δ9.59 (s, 1H), 8.11 (d, J = 8.8Hz, 2H), 7.87 (d, J = 4.8Hz, 2H) ,7.19(d,J=8.8Hz,2H),6.38(s,2H),5.65(s,2H),5.41(d,J=4.0Hz,1H),4.68-4. 56(m,1H),3.90(s,3H),2.39(s,9H),2.07-1.77(m,5H),1.71-1.53(m,5H),1.56- 1.34(m,2H),1.32-1.04(m,3H),1.02(s,3H),1.01-0.92(m,1H),0.80(s,3H)ppm.

[0095] 13C NMR(100MHz,DMSO-d6)δ219.68,189.32,166.09,164.22,143.23,139.27,1 36.60,136.57,130.89,130.07,129.66,126.61,122.18,114.33,113.41,11 3.31,75.56,55.85,52.98,50.79,49.50,47.61,46.83,37.53,36.24,35.31 ,31.13,30.87,30.21,27.26,21.44,20.06,19.97,19.92,18.99,13.20ppm.

[0096] Example 6

[0097] According to the preparation methods (1), (2) and (3) of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivatives proposed in the implementation method, the bromoalkane in step (3) is 4-bromophenylacetyl bromide, a white solid, with a yield of 89%, and the compound structure is as follows:

[0098]

[0099] Characterization Spectrum Reference Fig.15 , Fig.16 As shown: 1 H NMR(400MHz,DMSO-d6)δ9.58(s,1H),8.08-8.02(m,2H),7.93-7.86(m,4H),6 .43(s,2H),5.66(s,2H),5.41(d,J=5.0Hz,1H),4.69-4.56(m,1H),2.45-2.3 5(m,9H),2.10-1.93(m,2H),1.92-1.79(m,3H),1.67-1.61(m,5H),1.58-1.3 4(m,2H),1.32-1.05(m,3H),1.02(s,3H),1.01-0.90(m,1H),0.80(s,3H)ppm.

[0100] 13C NMR(100MHz,DMSO-d6)δ219.65,190.52,166.07,143.15,139.26,136.61, 132.85,132.14,130.39,130.02,129.64,128.68,122.17,113.48,113.32 ,75.56,53.39,50.78,49.49,47.64,46.82,37.52,36.27,36.23,35.30,3 1.12,30.86,30.20,27.25,21.43,20.05,19.99,19.91,18.98,13.20ppm.

[0101] The compounds obtained in Examples 1 to 6 were screened for cytotoxic activity against three tumor cell lines: breast cancer (MDA-MB-231), liver cancer (HepG2) and prostate cancer (22RV1) according to the MTS method. The half lethal dose IC 50 The results of the determination of the values ​​are compared with those of the commercialized anticancer drug, cisplatin (DDP), and are shown in the table below.

[0102] Table 1 The median lethal dose of the compounds of Examples 1 to 6 for different tumor cells

[0103]

[0104]

[0105] The data in Table 1 show that the compounds obtained in Examples 1 to 6 all have significant in vitro tumor growth inhibition activity against three human cancer cells (breast cancer, liver cancer, and prostate cancer), and the in vitro tumor growth inhibition activity of the three compounds (Examples 1, 3, and 6) is better than that of the anticancer drug cisplatin (DDP).

[0106] It can be seen from the above embodiments that the present invention provides a method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative, which can be used to prepare anti-tumor drugs and has good pharmacological activity; the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative obtained by the method has significant in vitro tumor growth inhibitory activity on human cancer cells (breast cancer, liver cancer, prostate cancer cells), and its in vitro tumor growth inhibitory activity is better than the anticancer drug cisplatin (DDP); at the same time, the preparation method provided by the present application is simple to operate and easy to implement.

[0107] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative, characterized in that: Its structural formula is shown in Formula I: Wherein, in Formula I, R is 4-methylbenzyl, 2-cyanobenzyl, 4-bromobenzyl, phenacyl, 4-methoxyphenacyl or 4-bromophenacyl, and the structural formula is as follows:

2. The method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative according to claim 1, characterized in that: The reaction scheme of the preparation method is as follows: The method comprises the following steps: S1: mixing dehydroepiandrosterone, chloroacetyl chloride, an organic solvent and an activating-acid-binding agent and performing an acetylation reaction to generate dehydroepiandrosterone-3β-ester; S2: mixing the dehydroepiandrosterone-3β-ester, 5,6-dimethylbenzimidazole and toluene and performing a substitution reaction to obtain dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole; S3: mixing the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole, bromoalkane and toluene and performing a salt-forming reaction to obtain a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative.

3. The method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative according to claim 2, characterized in that: The molar ratio of dehydroepiandrosterone, chloroacetyl chloride and activation-acid binding agent in S1 is 1:(1-2):(1-2); The ratio of the mass of the dehydroepiandrosterone to the volume of the organic solvent is 1 g: (10-20) mL.

4. The method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative according to claim 2, characterized in that: The molar ratio of dehydroepiandrosterone-3β-ester to 5,6-dimethylbenzimidazole in S2 is 1:(2.5-3.5); The ratio of the mass of the dehydroepiandrosterone-3β-ester to the volume of toluene is 1 g: (10-20) mL.

5. The method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative according to claim 2, characterized in that: The molar ratio of dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole to the bromide in S3 is 1:(1.5-2.5); The ratio of the mass of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole to the volume of toluene is 1 g: (50-150) mL.

6. The method for preparing a dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative according to claim 1, characterized in that: Application of the dehydroepiandrosterone-3β-ester-5,6-dimethylbenzimidazole bromide derivative in the preparation of anti-tumor drugs.

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