BENZIMIDAZOLE DERIVATIVE HAVING FLUORINE-CONTAINING SUBSTITUENT, PREPARATION AND APPLICATION THEREOF
20230040251 · 2023-02-09
Inventors
Cpc classification
A61K45/06
HUMAN NECESSITIES
C07D413/04
CHEMISTRY; METALLURGY
International classification
C07D413/04
CHEMISTRY; METALLURGY
A61K45/06
HUMAN NECESSITIES
Abstract
Disclosed are a benzimidazole derivative of formula (I), or an isomer, a pharmaceutically-acceptable salt, or a prodrug thereof, and a preparation thereof. An application of the benzimidazole derivative in the treatment of tumors is further provided.
##STR00001##
Claims
1. A benzimidazole derivative of formula (I), or an isomer, a pharmaceutically-acceptable salt, or a prodrug thereof: ##STR00022## wherein x is 0, 1, or 2; when m is 0, n is 2; and when m is 1, n is 1; y is 0, 1, 2, 3 or 4; R.sub.1 is each independently halogen, phenolic hydroxyl or a derivative thereof, carboxyl or a derivative thereof, an amino group or a derivative thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, sulfone or a sulphoxide derivative, a C.sub.1—C.sub.15 alkyl group or a derivative thereof, a C.sub.1—C.sub.15 alkenyl or a derivative thereof, a C.sub.1—C.sub.15 alkynyl or a derivative thereof, a C.sub.5—C.sub.8 aryl or a derivative thereof, naphthyl or a naphthol derivative, or a five-to-eight-membered heterocyclic or fused heterocyclic ring containing 1-4 heteroatoms; R.sub.2 is an amino group or a derivative thereof; and z is 0, 1, 2, 3 or 4; R.sub.3 is each independently halogen, phenolic hydroxyl or a derivative thereof, carboxyl or a derivative thereof, an amino group or a derivative thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, sulfone or a sulfoxide derivative, a C.sub.1—C.sub.15 alkyl group or a derivative thereof, a C.sub.1—C.sub.15 alkenyl or a derivative thereof, a C.sub.1—C.sub.15 alkynyl or a derivative thereof, a C.sub.5—C.sub.8 aryl or a derivative thereof, naphthyl or a naphthol derivative, or a five-to-eight-membered heterocyclic or fused heterocyclic ring containing 1-4 heteroatoms.
2. The benzimidazole derivative of claim 1, wherein the benzimidazole derivative is selected from the group consisting of: ##STR00023## ##STR00024## ##STR00025## ##STR00026##
3. A pharmaceutical composition, comprising: the benzimidazole derivative of claim 1, or an isomer, a pharmaceutically-acceptable salt, or a prodrug thereof; and a pharmaceutically-acceptable carrier, a pharmaceutically-acceptable diluent, a pharmaceutically-acceptable excipient, or a combination thereof.
4. A method of preparing the benzimidazole derivative of claim 1, comprising: (1) reacting compound (a) with acrylonitrile followed by purification to form compound (b); (2) reacting the compound (b) with compound (c) in a first solvent in the presence of a base followed by purification to obtain compound (d); (3) subjecting the compound (d) to fluorination in a second solvent in the presence of a fluorinating agent followed by purification to obtain compound (e), wherein the fluorinating agent is diethylaminosulfur trifluoride (DAST) or bis (2-methoxyethyl) aminosulfur trifluoride (BAST); and (4) converting R.sub.2′ in the compound (e) into R.sub.2 in a third solvent followed by purification to obtain compound (I-1), as shown in the following reaction scheme: ##STR00027## ##STR00028## wherein R.sub.2′ is nitro group or a protected amino group; the base is an inorganic base or an organic base; wherein the inorganic base is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium hydride, calcium hydride, calcium fluoride, cesium fluoride, sodium carbonate, potassium carbonate, cesium carbonate, potassium phosphate and a combination thereof; and the organic base is selected from the group consisting of lithium diisopropylamide, butyl lithium, lithium bis(trimethylsilyl)amide, triethylamine, diisopropylethylamine, 1, 8-diazabicyclo[5.4.0]undec-7-ene and a combination thereof; the first solvent, the second solvent and the third solvent are independently a proton solvent, an aprotic solvent, or a mixture thereof; steps (1)-(4) are independently performed at a temperature of −78-180° C.; purifications in steps (1)-(4) are performed each independently by solvent extraction, precipitation, crystallization, column chromatography or a combination thereof; and in the column chromatography, a filler is a gel, macro porous resin, or aluminum oxide; and an eluent is a petroleum ether-acetone mixture, a petroleum ether-ethyl acetate mixture, or a petroleum ether-dichloromethane mixture.
5. The method of claim 4, wherein the first solvent, the second solvent and the third solvent are each independently dichloromethane, dichloroethane, tetrahydrofuran, acetonitrile, ethylene glycol dimethyl ether, N, N-dimethylformamide, or dimethyl sulfoxide.
6. A method of preparing the benzimidazole derivative of claim 1, comprising: (1) reacting compound (b) with compound (c1) in a first solvent in the presence of a base followed by purification to produce compound (e1); and (2) converting R.sub.2′ in the compound (e1) into R.sub.2 in a second solvent followed by purification to obtain compound (I), as shown in the following reaction scheme: ##STR00029## wherein R.sub.2′ is nitro group or a protected amino group; the base is an inorganic base or an organic base; wherein the inorganic base is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium hydride, calcium hydride, calcium fluoride, cesium fluoride, sodium carbonate, potassium carbonate, cesium carbonate, potassium phosphate and a combination thereof; and the organic base is selected from the group consisting of lithium diisopropylamide, butyl lithium, lithium bis(trimethylsilyl)amide, triethylamine, diisopropylethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene and a combination thereof; the first solvent and the second solvent are independently a proton solvent, an aprotic solvent, or a mixture thereof; steps (1)-(2) are independently performed at a temperature of −78-180° C.; purifications in steps (1)-(2) are performed each independently by solvent extraction, precipitation, crystallization, column chromatography or a combination thereof; and in the column chromatography, a filler is a gel, macro porous resin, or aluminum oxide; and an eluent is a petroleum ether-acetone mixture, a petroleum ether-ethyl acetate mixture, or a petroleum ether-dichloromethane mixture.
7. The method of claim 6, wherein the first solvent and the second solvent are each independently dichloromethane, dichloroethane, tetrahydrofuran, acetonitrile, ethylene glycol dimethyl ether, N, N-dimethylformamide, or dimethyl sulfoxide.
8. A method for treating a cancer in a subject in need thereof, comprising: administering the benzimidazole derivative of claim 1, or an isomer, a pharmaceutically-acceptable salt, or a prodrug thereof to the subject.
9. The method of claim 8, wherein the cancer is selected from the group consisting of brain cancer, glioma, endometrial cancer, ovarian cancer, cervical cancer, breast cancer, colon cancer, lung cancer, prostate cancer, liver cancer, leukemia, lymphoma, skin cancer, basal cell carcinoma, hemangioma, uterine cancer, laryngeal cancer, gastric cancer, lip cancer, esophageal cancer, nasopharyngeal carcinoma, gallbladder cancer, pancreatic cancer, renal cancer, tongue cancer, bladder cancer, melanoma, lipoma, thyroid cancer, thymic cancer, and bone cancer.
10. The method of claim 8, wherein the benzimidazole derivative, or an isomer, a pharmaceutically-acceptable salt, or a prodrug thereof is administered in combination with an anticancer agent.
11. The method of claim 10, wherein the anticancer agent is selected from the group consisting of adriamycin, bleomycin, vincristine, taxane, etoposide, 5-fluorouracil, cyclophosphamide, methotrexate, cisplatin, retinoic acid, temozolomide, actinomycin, imatinib, gefitinib, sorafenib, erlotinib, sunitinib, afatinib, cabozantinib, Osimertinib, rituximab, cetuximab, trastuzumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, avelumab and a combination thereof.
Description
DETAILED DESCRIPTION OF EMBODIMENTS
[0050] This application will be described in detail below with reference to the embodiments to make objects, technical features and advantages of this application clearer, but these embodiments are not intended to limit the scope of this application. Other embodiments obtained by those skilled in the art based on the content disclosed herein without paying any creative efforts shall fall within the scope of this application.
Example 1 Preparation of Compound 1 (3-[(4-{1-[2-(4-aminophenyl)-2,2-difluoroethyl]-1H-benzimidazol-2-yl}-1,2,5-oxadiazol-3-yl)amino] propionitrile)
[0051] ##STR00011## ##STR00012##
(1) Preparation of Compound 1 a (3-{[4-(1H-benzimidazol-2-yl)-1,2,5-oxadiazol-3-yl]amino} propionitrile)
[0052] 4-(1H-benzimidazol-2-yl)-1,2,5-oxadiazol-3-amine (18.2 g, 90.5 mmol) was dissolved in 240 mL of anhydrous pyridine, cooled in ice water, and sequentially added with 30 mL of a solution of sodium methoxide (8.8 g, 162.9 mmol) in methanol and 6 mL of acrylonitrile (90.5 mmol). The reaction mixture was stirred at 60° C. overnight. After the reaction was confirmed by thin-layer silica gel chromatography to be completed, the reaction mixture was evaporated under reduced pressure, added with 300 mL of water and subjected to extraction three times each with 100 mL of ethyl acetate. The organic phases were combined, washed with 100 mL of saturated NaCl solution, dried with anhydrous sodium sulfate, and concentrated, and the residue was crystallized with ethyl acetate/n-hexane to obtain 15.8 g of compound 1a as white solid (68.7% yield).
[0053] MS: [M+1].sup.+=255.1.
[0054] .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ ppm:13.75 (brs, 1H), 7.81 (broad, 1H), 7.61 (m, 1H), 7.37-7.34 (m, 2H), 7.21 (t, J=6.4 Hz, 1H), 3.68 (q, J=6.4 Hz, 2H), 2.94 (t, J=6.4 Hz, 2H).
(2) Preparation of Compound 1b (3 -[(4-{1-[2-(4-nitrophenyl)-2-oxoethyl]-1H-benzimidazol-2-yl}-1,2,5-oxadiazol-3-yl) amino] propionitrile)
[0055] Compound 1a (270 mg, 1.1 mmol) was dissolved in 15 mL of anhydrous N, N-dimethylformamide, to which 2-bromo-1-(4-nitrophenyl)-ethanone (260 mg, 1.1 mmol) and potassium carbonate (276 mg, 2.0 mmol) were sequentially added. The reaction mixture was stirred overnight at room temperature. After the starting material was confirmed by thin-layer silica gel chromatography to be completely consumed, the reaction mixture was evaporated under reduced pressure, added with 100 ml of water and subjected to extraction three times each with 50 mL of ethyl acetate. The organic phases were combined, washed with 100 mL of saturated NaCl solution, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 459 mg of compound 1b as yellow solid (100% yield).
[0056] MS: [M+1].sup.+=418.1.
(3) Preparation of Compound 1 c (3 -[(4-{1-[2,2-difluoro-2-(4-nitrophenyl)ethyl]-1H-benzimidazol-2-yl}-1,2,5 -oxadiazol-3-yl)amino] propionitrile)
[0057] Compound 1b (417 mg, 1.0 mmol) was dissolved in dichloromethane (50 mL) under the protection of an inert gas, cooled to 0° C. in ice water, and slowly dropwise added with diethylaminosulfur trifluoride (DAST, 1 mL). The reaction mixture was heated to room temperature, and stirred for 12 hours. After the starting material was confirmed by thin-layer silica gel chromatography to be completely consumed, the reaction mixture was quenched with water (50 mL), and the aqueous layer was separated followed by extraction twice each with 30 mL of dichloromethane. The organic phases were combined, dried with anhydrous sodium sulfate, concentrated and purified by silica gel column chromatography (eluent: a mixture of ethyl acetate and petroleum ether in a volume ratio of 2:3) to obtain 140 mg of intermediate 1c (33.0% yield).
[0058] MS: [M+1].sup.+=440.1.
[0059] .sup.1H NMR (400 MHz, CDCl.sub.3) δ ppm: 8.17 (d, J=8.4 Hz, 2H), 7.80 (d, J=8.0 Hz, 1H), 7.50-7.53 (m, 3H), 7.30-7.49 (m, 3H), 5.29 (t, J=13.6 Hz, 2H), 3.69 (m, 2H), 2.77 (t, J=6.4 Hz, 2H).
(4) Preparation of Compound 1 (3-[(4-{1-[2-(4-aminophenyl)-2,2-difluoroethyl]-1H-benzimidazol-2-yl}-1,2,5-oxadiazol-3-yl)amino] propionitrile)
[0060] A solution of compound 1c (140 mg, 0.34 mmol) in dichloromethane (20 mL) was sequentially added with glacial acetic acid (1 mL) and zinc powder (150 mg) at room temperature. The reaction mixture was stirred at room temperature for 4 hours. When displayed that the starting material was confirmed by the thin-layer silica gel chromatography to be completely consumed, the reaction mixture was filtered to remove insoluble substances, and concentrated, and the residue was purified by Prep-HPLC to obtain 75 mg of compound 1 as yellow solid (56.0% yield), where the mobile phase was a mixture of acetonitrile and 0.01% aqueous ammonia.
[0061] MS: [M+1].sup.+=410.1.
[0062] .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ ppm: 7.86 (d, J=8.8 Hz, 2H), 7.40-7.50 (m, 3H), 7.16 (d, J=8.4 Hz, 2H), 6.60 (d, J=8.4 Hz, 2H), 5.56 (brs, 2H), 5.44 (t, J=14.8 Hz, 2H), 3.67 (m, 2H), 2.94 (t, J=6.8 Hz, 2H).
[0063] Similarly, compounds 2-7 were prepared, and corresponding mass spectrometry and NMR data were shown in Table 1.
TABLE-US-00001 TABLE 1 Mass spectrum and .sup.1H NMR data of compounds 2-7 .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ Compounds Structural formula MS: [M + 1].sup.+ ppm: 2
Example 2 Preparation of Compound 8 (3-[(4-{1-[2-(4-aminophenyl)-2-fluoroethyl]-1H-benzimidazol-2-yl}-1,2,5-oxadiazol-3-yl) amino] propionitrile)
[0064] ##STR00019##
(1) Preparation of Compound 8a (3-[(4-{1-[2-fluoro-2-(4-nitrophenyl)ethyl]-1H-benzimidazol-2-yl}-1,2,5-oxadiazol-3-yl)amino] propionitrile)
[0065] To a reaction flask were sequentially added 1-(2-bromo-1-fluoroethyl)-4-nitrobenzene (496 mg, 2.0 mmol), potassium carbonate (280 mg, 2.0 mmol), 3-{[4-(1H-benzimidazole-2-yl)-1,2,5-oxadiazol-3-yl]amino} propanenitrile (254 mg, 1.0 mmol), and anhydrous N, N-dimethylformamide (20 mL) to obtain a reaction mixture. The reaction mixture was stirred at 80° C. under for 4 hours, and filtered to remove insoluble substances. After that, the filtrate was diluted with 200 ml of ethyl acetate and washed with water for three times and saturated brine for once. The organic phase was dried with anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/petroleum ether=2/3) to obtain 160 mg of intermediate compound 8a, (38.0% yield).
[0066] MS: [M+1].sup.+=422.1
[0067] .sup.1H NMR (400 MHz, CDCl.sub.3) δ ppm: 8.15(d, J=8.4 Hz, 2H), 7.78 (d, J=8.4 Hz, 1H), 7.45-7.51 (m, 3H), 7.25-7.45 (m, 3H), 5.20 (m, 1H), 4.25 (m, 2H), 3.65 (m, 2H), 2.76 (t, J=6.4 Hz, 2H).
(2) Preparation of compound 8 (3-[(4-{1-[2-(4-aminophenyl)-2-fluoroethyl]-1H-benzimidazol-2-yl}-1,2,5-oxadiazol-3-yl) amino] propionitrile)
[0068] A dichloromethane solution (20 mL) of compound 8a (160 mg, 0.38 mmol) was sequentially added with glacial acetic acid (1 mL) and zinc powder (180 mg) at room temperature, and then stirred at room temperature for 4 hours to obtain a reaction mixture. After the starting material was confirmed by thin-layer silica gel chromatography to be completely consumed, the reaction mixture was filtered to remove insoluble substances, and concentrated to remove the solvent. After that, the residue was purified by Prep-HPLC to obtain 80 mg of compound 8 as yellow solid (54.0% yield), where the mobile phase used in Prep-HPLC was a mixture of acetonitrile and water, or a mixture of acetonitrile and 0.01% aqueous ammonia.
[0069] MS: [M+1].sup.+=392.1
[0070] 1H NMR (400 MHz, DMSO-d.sub.6) δ ppm: 7.84 (d, J=8.4 Hz, 2H), 7.39-7.50 (m, 3H), 7.14 (d, J=8.4 Hz, 2H), 6.58 (d, J=8.4 Hz, 2H), 5.92 (m, 1H), 5.40 (brs, 2H), 4.50 (m, 2H), 3.99 (m, 1H), 3.65 (m, 2H), 2.93 (t, J=6.8 Hz, 2H).
[0071] Compounds 9-10 were obtained by similar methods for synthesizing compound 8, and corresponding spectrogram data were shown in Table 2.
TABLE-US-00002 TABLE 2 The mass spectrum and .sup.1H NMR data of compounds 9-10 .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ Compounds Structural formula MS: [M + 1].sup.+ ppm: 9
Example 3 Calculation of ClogP Values of Compounds 1-11
[0072] The ClogP value refers to a logarithmic value of the ratio of the distribution coefficient of a substance in n-octanol (oil) to that in water, reflecting the distribution condition of the substance in the oil and water phases. The larger the clogP value, the more lipophilic the substance was, otherwise, the smaller the clogP value, the more hydrophilic the substance was, and the better the water solubility. The dissolution, absorption, distribution, and transport of a drug in vivo were related to the hydrophilia and lipophilia of the drug, that is, the oil-water distribution coefficient clogP. The clogP values of compounds 1-11 prepared herein were calculated by an online tool (http://www.vcclab.org/lab/alogps/) provided by Virtual Computational Chemistry Laboratory (VCCLAB), as shown in Table 3.
TABLE-US-00003 TABLE 3 clogP values of compounds 1-11 Compounds 1 2 3 4 5 6 7 8 9 10 11 clogP 3.38 2.97 2.97 3.97 3.97 4.20 3.72 3.17 3.44 3.54 2.57
[0073] Table 3 shows that the clogP values of the compounds 1 -10 were all higher than that of the compound 11, indicating that the compounds 1-10 had better lipophilia.
Example 4 Inhibitory Effects of Compounds 1-11 on the Proliferation of Tumor Cells
[0074] Experimental Purposes
[0075] The anti-proliferation activities of compounds 1-11 to U87MG cells (human malignant glioma cells, ATCC 5018014), NCI-H1975 cells (human non-small cell lung adenocarcinoma cells, ATCC 57849016), A549 cells (human non-small cell lung cancer cells, ATCC 7503618), HCT 116 (human colon cancer cells, ATCC 4587576), and MCF-7 (human breast cancer cells, ATCC 5105360) were verified by using a CCK-8 method.
[0076] Experimental Method
[0077] A sample stock solution with a concentration of 20 μM was prepared first. The stock solution was sequentially diluted to obtain 10 samples with concentrations of 20000 nM, 4000 nM, 800 nM, 160 nM, 32 nM, 6.4 nM, 1.28 nM, 0.256 nM, 0.0512 nM, and 0.01024 nM, respectively.
[0078] 50 μL of cell suspension with density of 2*10.sup.4 cells/mL was prepared in 96-well plates followed by pre-culturing in the incubator for 24 hours (37° C., 5% CO.sub.2). 50 μL of afore-mentioned sample solution was added into each well. After incubated for 72 hours, 10 μl of CCK-8 solution was added into each well, and then further incubated for additional 2 hours. The OD value was measured at the wavelength of 450 nm with a full-automatic ELISA instrument, and the data was processed by GraphPad Prism 7 to calculate IC.sub.50.
[0079] The experimental results were shown in Table 4.
TABLE-US-00004 TABLE 4 IC.sub.50 values of compounds 1-11 regarding inhibitory effect on proliferation of various tumor cells U87MG NCI-H1975 A549 HCT116 MCF-7 cell cell cell cell cell Compounds IC.sub.50 (μM) IC.sub.50 (μM) IC.sub.50 (μM) IC.sub.50 (μM) IC.sub.50 (μM) 1 0.0313 0.0194 0.0290 0.0197 0.0330 2 0.0224 0.0312 0.0182 0.0283 0.0174 3 0.0132 0.0133 0.0268 0.0136 0.0132 4 0.0273 0.0149 0.0129 0.0121 0.0217 5 0.0157 0.0274 0.0132 0.0358 0.0169 6 0.0342 0.0119 0.0147 0.0172 0.0132 7 0.0125 0.0324 0.0139 0.0137 0.0257 8 0.0156 0.0175 0.0337 0.0244 0.0228 9 0.0239 0.0198 0.0287 0.0285 0.0328 10 0.0412 0.0343 0.0415 0.0387 0.0385 11 0.0512 0.0428 0.0424 0.0526 0.0392
[0080] The results showed that for the five tested tumor cells, the inhibitory proliferation activity of the compounds 1-10 in vitro were all higher than that of the reference compound 11.
Example 5 Determination of Half-Lethal Dose (LD.SUB.50.)
[0081] Experimental Purpose
[0082] The toxicities of compounds 1-11 were evaluated by measuring the half-lethal dose (LD.sub.50).
[0083] Experimental Method
[0084] The SPF-grade Kunming mice, belonging to the outbred stock and weighing 20±2 g, were selected (a ratio of the males to the females was 1:1). The dosage range of each compound was explored through pre-experiments. After that, formal tests were carried out. In the range of 0-100% of the lethal dose obtained by the pre-experiments, five doses were selected to increase or decrease according to the isobaric series to allow the mortality of one half of the groups to be 50% or above, and the other half to be 50% or less. After animal grouping and dosage calculation were completed, gastric administration was performed according to the group. The time from the administration to the beginning of the occurrence of toxic reaction, the poisoning phenomenon and the occurrence sequence thereof, the time of the first occurrence of death, the time of death concentration, and the time of the last occurrence of death were recorded. The number of deaths in each group was recorded day by day. The LD.sub.50 was calculated according to the test results by using a Bliss calculation method, and the results were shown in Table 5.
TABLE-US-00005 TABLE 5 Half-lethal dose (LD.sub.50) of compounds 1-11 for mice Compounds 1 2 3 4 5 6 7 8 9 10 11 LD.sub.50(mg/KG) 267 245 239 262 264 254 239 291 305 323 153
[0085] The results showed that the half-lethal dose LD.sub.50 values of the compounds 1-10 were higher than that of the compound 11, that was, the toxicity of the compounds 1-10 was lower than that of the compound 11.
[0086] The above embodiments are merely illustrative, and are not intended to limit the present disclosure. It should be noted that various modifications and improvements made by one of ordinary skill in the art without departing from the spirit of the present disclosure shall fall within the scope of the present disclosure defined by the appended claims.