2-methyl-6-phenyl-8-carbonyl purine compound as well as preparation method and medical application thereof

Abstract

The invention belongs to the field of medicines, and discloses a 2-methyl-6-phenyl-8-carbonyl purine compound as well as a preparation method and medical application thereof. The 2-methyl-6-phenyl-8-carbonyl purine compound has a structure as shown in a general formula I. The 2-methyl-6-phenyl-8-carbonyl purine compound selectively has a strong inhibition effect on proliferation of tumor cells such as lung cancer, breast cancer, colon cancer and liver cancer, and can be applied to preparation of medicines for treating and / or preventing malignant tumors.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceuticals, specifically relating to a 2-methyl-6-phenyl-8-carbonylpurine compound, its preparation method, and its pharmaceutical uses. Background Technology

[0002] Cancer, as one of the leading causes of death in humans, seriously threatens human health and life. Although there are many drugs available for cancer treatment in clinical practice, due to the complexity, heterogeneity, drug resistance, and metastasis of cancer etiology, existing drugs still cannot meet clinical treatment needs. Therefore, the search for novel cancer drugs that are highly effective, low in toxicity, and have strong targeting is of great significance.

[0003] Compounds with purine-like structures exhibit significant advantages in cancer treatment due to their unique chemical structure and biological activity. These compounds, by mimicking purine analogs, can integrate into DNA or RNA, interfering with DNA synthesis and repair in cancer cells, thereby inhibiting cancer cell proliferation. Furthermore, they can target multiple key cancer-related signaling pathways, such as the PI3K / AKT / mTOR and RAS / MAPK pathways, inhibiting tumor growth and metastasis. Simultaneously, purine-like compounds induce cancer cell apoptosis by activating mitochondrial-dependent apoptosis pathways or upregulating pro-apoptotic proteins (such as Bax and p53), further enhancing their anti-cancer effects. Summary of the Invention

[0004] The purpose of this invention is to provide a 2-methyl-6-phenyl-8-carbonylpurine compound, its preparation method, and its pharmaceutical uses. This 2-methyl-6-phenyl-8-carbonylpurine compound has a strong inhibitory effect on the proliferation of various tumor cells, including lung cancer, breast cancer, colon cancer, and liver cancer.

[0005] In a first aspect, the present invention provides a 2-methyl-6-phenyl-8-carbonylpurine compound having the structure of general formula I:

[0006]

[0007] Wherein, R1 is selected from One of them.

[0008] The preferred compound designations and corresponding structures of the above general formula I are shown in Table 1:

[0009] Table 1. Compound codes and corresponding structures for some compounds of general formula I.

[0010]

[0011] In a second aspect, the present invention provides a method for preparing the above-described 2-methyl-6-phenyl-8-carbonylpurine compound, wherein the synthetic route of the preparation method is shown in the following formula:

[0012]

[0013] The preparation method includes the following steps:

[0014] S1.R1-CH2NH2 undergoes a substitution reaction with compound 1 under organic basic conditions to give compound 2;

[0015] Wherein, R1 is selected from One of them;

[0016] S2. Compound 2 reacts with excess carbonyl diimidazole (CDI) via a Dieckmann condensation reaction to give compound 3;

[0017] S3. Compound 3 and phenylboronic acid were coupled via a Suzuki coupling reaction in the presence of sodium carbonate, Pd(OAc)2 and sodium triphenylphosphine trimethylsulfonate (TPPTS) to give 2-methyl-6-phenyl-8-carbonylpurine compound I.

[0018] Furthermore, in step S1, the molar ratio of compound 1 to R1-CH2NH2 is 3:3.3; the reaction conditions for the substitution reaction are: N2 protection, reaction at 120°C for 2 days.

[0019] Furthermore, in step S2, the molar ratio of compound 2 to CDI is 2.59:(12-13).

[0020] Furthermore, in step S2, the reaction conditions for the Dieckmann condensation reaction are: N2 protection, reaction at 30°C for 12 hours.

[0021] Furthermore, in step S3, the molar ratio of compound 3 to phenylboronic acid is 0.28:0.34.

[0022] Furthermore, in step S3, the conditions for the Suzuki coupling reaction are: N2 protection, reaction at 100°C for approximately 3 hours.

[0023] Thirdly, the use of the aforementioned 2-methyl-6-phenyl-8-carbonylpurine compounds or pharmaceutically acceptable salts thereof as active ingredients in the preparation of medicaments for the treatment and / or prevention of malignant tumors, wherein the malignant tumor is one of liver cancer, lung cancer, colon cancer, and breast cancer.

[0024] Compared with existing technologies, this invention, referencing the potential therapeutic value of purine analogs in antitumor activity, utilizes the principle of electron isosterism to select purine as the core of the large skeleton to occupy the active site cavity. A carbonyl group is introduced onto the imidazole ring of the purine to form a ureidyl fragment, thereby forming an 8-carbonylpurine skeleton. Furthermore, a phenyl group is introduced at the 6-position to enhance lipophilicity. Simultaneously, based on the narrow and elongated characteristics of the target pocket region, the substituents on the parent core are adjusted, thus designing and developing a class of 2-methyl-6-phenyl-8-carbonylpurine compounds with strong antitumor activity. Activity tests on various types of cancer cells revealed that these compounds exhibit strong inhibitory effects on the proliferation of various tumor cells (including lung cancer, breast cancer, colon cancer, and liver cancer). In particular, when R1 is a lipophilic long-chain alkyl group substituted with Boc amino, pentylamide, or chloroacetamide, the inhibitory activity is significantly superior to the positive control SKPin C1. Therefore, the compounds of this invention have significant pharmaceutical application prospects in the preparation of anticancer drugs. Detailed Implementation

[0025] To further illustrate the present invention, a series of embodiments are given below. These embodiments are purely illustrative and are only used to specifically describe the present invention, and should not be construed as limiting the present invention. It should be understood that, within the scope of the present invention, the above-described technical features of the present invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to constitute preferred technical solutions.

[0026] Example 1: Preparation of tert-butyl 4-((2-methyl-8-oxo-6-phenyl-7,8-dihydro-9H-purin-9-yl)methyl)piperidine-1-carboxylate (I1)

[0027] Compound 1 (534 mg, 3 mmol), 1-Boc-4-(aminomethyl)piperidine (354 mg, 3.3 mmol), TEA (1.1 mL, 9 mmol), and n-butanol (6 mL) were added sequentially to a Schlenk tube. The tube was protected with N2 and reacted at 120 °C for 2 days. After the reaction was completed by TLC monitoring, the reaction mixture was evaporated to dryness. The solution was purified by column chromatography using dichloromethane / methanol (100:1, v / v) as the eluent to obtain a white solid 2a with a yield of 86%. 1 HNMR(400MHz,DMSO-d6)δ6.66(m,1H,NH),4.79(s,2H,NH2),3.93(d,J=13.1Hz,2H,CH2),3.27(t,J=6.0Hz,2H,CH2 ),2.76-2.61(m,2H,CH2),2.22(s,3H,CH3),1.82-1.62(m,3H,CH2,CH),1.39(s,9H,CH3),1.11-0.97(m,2H,CH2).

[0028] Compound 2a (645 mg, 2.59 mmol) was dissolved in anhydrous tetrahydrofuran (13 ml) under N2 protection. CDI (2 g, 12.97 mmol) was added to the solution, and the reaction was carried out at 30 °C for 12 h. After the reaction was completed by TLC monitoring, water was slowly added to the reaction solution to quench excess CDI, and then an appropriate amount of water was added and stirred. After a large amount of solid precipitated, the mixture was filtered and the filter cake was dried to obtain white solid 3a with a yield of 67%. 1 H NMR (400MHz, DMSO-d6) δ3.90(d,J=12.9Hz,2H,),3.67(d,J=7.2Hz,2H),2.52(s,3H),1.99(s,4H),1.61-1.51(m,2H),1.39(s,9H),1.07(m,2H).

[0029] Compound 3a (77 mg, 0.28 mmol), phenylboronic acid (41.5 mg, 0.34 mmol), sodium carbonate (59.4 mg, 0.56 mmol), palladium acetate (3.2 mg, 0.014 mmol), and trisodium triphenylphosphine tris(m-sulfonate) (20 mg, 0.035 mmol) were added to a Schlenk tube under N2 protection. Water:acetonitrile (2:1, 6 mL) was added to the Schlenk tube as solvent, and the reaction was carried out at 100 °C for about 3 h. After the reaction was completed by TLC monitoring, the reaction solution was extracted with ethyl acetate and water. The ethyl acetate layer was evaporated to dryness, and dichloromethane / methanol (100:1, v / v) was used as the eluent for column chromatography. After purification, a white solid I1 was obtained with a yield of 80%. 1 HNMR (400MHz, DMSO-d6) δ11.71(s,1H,CONH),8.68(d,J=11.4Hz,1H,NH),7.97(m,J=7.3,2.1Hz,2H,ArH),7.55(d,J=6.6Hz,3H,ArH),3.37(s,H,CH) ,3.26(d,J=12.5Hz,2H,CH2),2.93-2.77(m,2H,CH2),2.62(s,3H,CH3),2.16(s,2H,CH2),1.78(d,J=14.4Hz,2H,CH2),1.44(m,J=12.4Hz,2H,CH2).

[0030] Example 2: Preparation of (1-benzoylpiperidin-4-yl)methyl-2-methyl-6-phenyl-7,9-dihydro-8H-purine-8-one (I2)

[0031] Following the preparation method of 2a in Example 1, 1-Boc-4-(aminomethyl)piperidine was substituted for 1-Boc-4-(aminomethyl)piperidine in the method, and after purification, a white solid 2b was obtained with a yield of 64%. 1 H NMR (400MHz, DMSO-d6) δ7.38 (s, 1H, NH), 7.26 (d, J = 8.0Hz, 2H, ArH), 7.18 (m, 3H, ArH), 4.83 (s,2H,NH2),3.69(m,4H,CH2),3.17(m,2H,CH2),2.22(s,3H,CH3),1.38-1.59(m,5H,CH3).

[0032] Referring to the preparation method of 3a in Example 1, 2a was replaced by compound 2b to obtain white solid 3y with a yield of 84%. 1 H NMR (400MHz, DMSO-d6) δ12.02(s,1H,NH),7.38(s,1H,NH),7.24(d,J=8.1Hz,2H,ArH),7.18(m,3 H, ArH), 3.68 (m, 4H, CH2), 3.17 (d, J = 6.2Hz, 2H, CH2), 2.24 (s, 3H, CH3), 1.37-1.65 (m, 5H, CH3).

[0033] Referring to the preparation method of I1 in Example 1, 3y was substituted for 3a in the method, and after purification, a white solid compound I2 was obtained with a yield of 80%. 1 H NMR(400MHz,DMSO-d6)δ11.89(s,1H,NH),7.36-7.45(m,3H,NH,ArH),7.26(m,2H,ArH),7.14-7.18( m,6H,ArH),3.66(m,4H,CH2),3.16(d,J=6.2Hz,2H,CH2),2.24(s,3H,CH3),1.39-1.65(m,5H,CH3).

[0034] Example 3: Preparation of tert-butyl (5-(2-methyl-8-oxo-6-phenyl-7,8-dihydro-9H-purin-9-yl)pentyl)carbamate (I3)

[0035] Referring to the preparation method of 2a in Example 1, tert-butyl N-(5-aminopentyl)carbamate was substituted for 1-Boc-4-(aminomethyl)piperidine in the method, and after purification, a white solid 2c was obtained with a yield of 64%. 1H NMR (400MHz, DMSO-d6) δ11.55(s,1H),6.79(m,1H),3.82(m,2H),2.89(m,2H),2.60(s,3H),1.71(m,2H),1.34-1.51(m,11H),1.16-1.25(m,2H).

[0036] Referring to the preparation method of 3a in Example 1, 2a was replaced by compound 2c to obtain white solid 3c with a yield of 84%. 1 H NMR (400MHz, DMSO-d6) δ11.89(s,1H),6.76(t,J=5.6Hz,1H),3.76(t,J=7.0Hz ,2H),2.87(m,2H),2.52(s,3H),1.67(m,2H),1.35(m,11H),1.16-1.29(m,2H).

[0037] Referring to the preparation method of I1 in Example 1, compound 3c was substituted for 3a in the method, and after purification, a white solid compound I3 was obtained with a yield of 80%. 1 H NMR (400MHz, DMSO-d6) δ11.55(s,1H),8.03-7.94(m,2H),7.59-7.47(m,3H),6.79(t,J=5.7H z,1H),3.82(m,2H),2.89(m,2H),2.60(s,3H),1.71(m,2H),1.35(m,11H),1.16-1.29(m,2H).

[0038] Example 4: Preparation of tert-butyl (6-(2-methyl-8-oxo-6-phenyl-7,8-dihydro-9H-purine-9-yl)hexyl)carbamate (I4).

[0039] Following the preparation method of 2a in Example 1, methyl 6-aminohexanoate hydrochloride was used to replace 1-Boc-4-(aminomethyl)piperidine in the method, and after purification, a white solid 2d was obtained with a yield of 64%. 1 H NMR(400MHz,DMSO-d6)δ6.79(t,J=5.8Hz,1H,NH),6.63(t,J=5.2Hz,1H,NH),4.76(s,2H,NH2),3.34- 3.30(m,1H,CH),2.90(m,2H,CH2),2.22(s,3H,CH3),1.53(m,2H,CH2),1.16-1.37(m,15H,CH2,CH3).

[0040] Referring to the preparation method of 3a in Example 1, 2a was replaced by compound 2d to obtain white solid 3d with a yield of 84%. 1 H NMR (400MHz, DMSO-d6) δ11.89(s,1H,NH),6.76(t,J=5.7Hz,1H,NH),3.77(t,J=7.1Hz,2 H,CH2),2.87(m,2H,CH2),2.52(s,3H,CH3),1.66(m,2H,CH2),1.13-1.36(m,15H,CH3).

[0041] Referring to the preparation method of I1 in Example 1, compound 3d was substituted for 3a in the method, and after purification, a white solid compound I4 was obtained with a yield of 80%. 1 H NMR (400MHz, DMSO-d6) δ11.55(s,1H,NH),8.02-7.96(m,2H,ArH),7.58-7.47(m,3H,ArH),6.78(t,J=5.7Hz,1H, NH),3.82(t,J=7.1Hz,2H,CH2),2.88(m,2H,CH2),2.60(s,3H,CH3),1.70(m,2H,CH2),1.15-1.36(m,15H,CH3).

[0042] Example 5: Preparation of tert-butyl (4-(2-methyl-8-oxo-6-phenyl-7,8-dihydro-9H-purine-9-yl)butyl)carbamate (I5).

[0043] Referring to the preparation method of 2a in Example 1, the compound (S)-2,5-diaminopentanoic acid methyl ester dihydrochloride was substituted for 1-Boc-4-(aminomethyl)piperidine in the method, and after purification, a white solid 2e was obtained with a yield of 64%. 1 H NMR(400MHz,DMSO-d6)δ6.82(s,1H,NHBoc),6.65(s,1H,NH),4.76(br,2H,NH2),3.32(d,J=6.2Hz,2H, CH2),2.94(m,2H,CH2),2.23(s,3H,CH3),1.51(m,2H,CH2),1.47-1.39(m,2H,CH2),1.37(s,9H,CH3).

[0044] Referring to the preparation method of 3a in Example 1, 2a was replaced by compound 2e to obtain white solid 3e with a yield of 84%. 1H NMR(400MHz,DMSO-d6)δ11.90(s,1H,NH),6.79(s,1H,NHBoc),3.77(t,J=6.9Hz, 2H,CH2),2.92(m,2H,CH2),2.52(s,3H,CH3),1.65(m,2H,CH2),1.18-1.35(s,11H CH 3, CH2).

[0045] Referring to the preparation method of I1 in Example 1, 3e was substituted for 3a in the method, and after purification, a white solid compound I5 was obtained with a yield of 80%. 1 HNMR(400MHz,DMSO-d6)δ11.57(s,1H,NH),8.02-7.95(m,2H,ArH),7.57-7.49(m,3H,ArH),6.82(t,J=5.7Hz,1H,NH),3 .83(t,J=6.9Hz,2H,CH2),2.94(m,2H,CH2),2.60(s,3H,CH3),1.69(t,J=7.9Hz,2H,CH2),1.17-1.35(s,11H,CH3,CH2). 13 C NMR(101MHz,DMSO)δ159.41,156.06,154.30,151.97,141.02,135.49,130.2 6,129.15,128.53,116.24,77.85,40.55,39.93,28.70,27.19,25.99,25.61.

[0046] Example 6: Preparation of 2-methyl-6-phenyl-9-(piperidin-4-aminomethyl)-7,9-dihydro-8H-purine-8-one (I6).

[0047] Compound I1 (130 mg, 0.31 mmol) was mixed with methanol (6 ml) and 4 M hydrochloric acid methanol solution (3 ml) was added. The reaction was allowed to proceed for approximately 12 hours. After the reaction was completed as monitored by TLC, the reaction mixture was evaporated to dryness to obtain compound I6. Whitesolid (92 mg, yield: 83%): 1HNMR(400MHz,DMSO-d6)δ11.71(s,1H,CONH),8.68(d,J=11.4Hz,1H,NH),8.35( s,1H,HCl),7.97(m,J=7.3,2.1Hz,2H,ArH),7.55(d,J=6.6Hz,3H,ArH),3.37(s ,H,CH),3.26(d,J=12.5Hz,2H,CH2),2.93-2.77(m,2H,CH2),2.62(s,3H,CH3), 2.16(s,2H,CH2),1.78(d,J=14.4Hz,2H,CH2),1.44(m,J=12.4Hz,2H,CH2).13C NMR (101MHz, DMSO) δ159.42,154.47,152.15,141.18,135.38,130.34,129.19,128.55,116.29,53.42,44.44,39.66,33.11,26.05.

[0048] Example 7: Preparation of N-[5-(2-methyl-8-oxo-6-phenyl-7,8-dihydro-9H-purine-9-yl)pentyl]pentylamide (I7).

[0049] Compound I3 (50 mg, 0.16 mmol) was dissolved in anhydrous THF (4 mL) under N2 protection. DIPEA (221 mg, 1.6 mmol) was added, and pentanoyl chloride (39 mg, 0.32 mmol) was slowly added dropwise under ice bath conditions. After the reaction stabilized, the mixture was allowed to return to room temperature for approximately 6 hours. The reaction solution was extracted with ethyl acetate and water. The ethyl acetate layer was purified by column chromatography using dichloromethane / methanol (100:1, v / v) as the eluent to give a white solid, compound I7. (White solid (50 mg, yield: 65%)) 1 H NMR (400MHz, DMSO-d6) δ11.55(s,1H),8.02-7.94(m,2H),7.58-7.47(m,3H),7.39(t,J=5 .6Hz,1H),3.02(m,2H),2.60(s,3H),1.72(m,2H),1.45(m,2H),1.26(m,4H),1.03(s,9H). 13C NMR(101MHz,DMSO)δ177.63,167.85,159.42,154.30,151.99,141.03,135.51,13 1.87,130.27,129.16,116.24,53.09,40.35,39.52,38.93,29.06,27.83,26.01.

[0050] Example 8: Preparation of 2-chloro-N-[5-(2-methyl-8-oxo-6-phenyl-7,8-dihydro-9H-purine-9-yl)pentyl]acetamide (I8).

[0051] Compound I3 (50 mg, 0.16 mmol) was added to anhydrous THF (2 ml) containing 1 M HCl. After reacting under N2 protection for 2 h, the reaction solution was neutralized with triethylamine, and DIPEA (221 mg, 1.6 mmol) was added. Chloroacetyl chloride (36 mg, 0.32 mmol) was slowly added dropwise under ice bath conditions. After the reaction stabilized, the solution was brought to room temperature and reacted for approximately 6 h. The reaction solution was extracted with ethyl acetate and water. The ethyl acetate layer was then column-secred to obtain compound I8. White solid (30 mg, yield: 65%): 1 H NMR(400MHz,DMSO-d6)δ11.56(s,1H),8.20(s,1H),7.98(m,2H),7.60-7.44(m,3H),4.01(s,2H) ,3.83(t,J=7.1Hz,2H),3.07(m,2H),2.60(s,3H),1.78-1.68(m,2H),1.48(m,2H),1.31(m,2H).

[0052] Example 9: In vitro antitumor activity experiment

[0053] H1299 (human lung cancer cell line), HT29 (human colon cancer cell line), MCF7 (human breast cancer cell line), and HepG2 (human liver cancer cell line) were selected to determine the inhibitory rate of the target compound I on the test cells. SKPin C1 was used as a positive control. Detailed test results are shown in Table 2.

[0054] Table 2. Inhibitory activity of the compounds of the present invention against human tumor cells

[0055]

[0056] ND: Not detected.

[0057] As shown in Table 2, these compounds selectively exhibit strong inhibitory effects on the proliferation of various tumor cells (including lung cancer, breast cancer, colon cancer, and liver cancer). In particular, when R1 is a lipophilic long-chain alkyl group substituted with Boc amino, pentylamide, or chloroacetamide, the inhibitory activity is significantly superior to the positive control drug SKPin C1. Therefore, the compounds of this invention have significant potential for pharmaceutical applications.

[0058] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A 2-methyl-6-phenyl-8-carbonylpurine compound, characterized in that, The 2-methyl-6-phenyl-8-carbonylpurine compounds have the structure shown in general formula I: Wherein, R1 is selected from One of them.

2. A method for preparing the 2-methyl-6-phenyl-8-carbonylpurine compound as described in claim 1, characterized in that, The synthetic route of the preparation method is shown in the following formula: The preparation method includes the following steps: S1.R1-CH2NH2 undergoes a substitution reaction with compound 1 under organic basic conditions to give compound 2; Wherein, R1 is selected from One of them; S2. Compound 2 reacts with excess carbonyl diimidazole via a Dieckmann condensation reaction to give compound 3; S3. Compound 3 and phenylboronic acid were coupled via a Suzuki coupling reaction in the presence of sodium carbonate, Pd(OAc)2 and sodium triphenylphosphine tris(m-sulfonate) to give 2-methyl-6-phenyl-8-carbonylpurine compound I.

3. The preparation method according to claim 2, characterized in that, The organic base is triethylamine or N,N-diisopropylethylamine.

4. The preparation method according to claim 2, characterized in that, In step S1, the molar ratio of compound 1 to R1-CH2NH2 is 3:3.

3.

5. The preparation method according to claim 2, characterized in that, In step S1, the reaction conditions for the substitution reaction are: solvent is n-butanol, N2 protection, reaction at 120°C for 2 days.

6. The preparation method according to claim 2, characterized in that, In step S2, the molar ratio of compound 2 to CDI is 2.59:(12-13).

7. The preparation method according to claim 2, characterized in that, In step S2, the reaction conditions for the Dieckmann condensation reaction are: N2 protection, reaction at 30°C for 12 hours.

8. The preparation method according to claim 2, characterized in that, In step S3, the molar ratio of compound 3 to phenylboronic acid is 1:1.

2.

9. The preparation method according to claim 2, characterized in that, In step S3, the conditions for the Suzuki coupling reaction are: N2 protection, reaction at 100°C for about 3 hours.

10. The use of the 2-methyl-6-phenyl-8-carbonylpurine compound of claim 1 or a pharmaceutically acceptable salt thereof as an active ingredient in the preparation of a medicament for the treatment and / or prevention of malignant tumors, wherein the malignant tumor is one of liver cancer, lung cancer, colon cancer and breast cancer.

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