1,3,4-Oxadiazole triazole compounds as histone deacetylase 6 inhibitors and pharmaceutical compositions containing the same

Abstract

The present invention relates to a compound with a novel structure having histone deacetylase 6 (HDAC6) inhibitory activity, its stereoisomers, its pharmaceutically acceptable salts, their uses for manufacturing drugs, pharmaceutical compositions containing them, a method for prevention or treatment, and a method for manufacturing a novel 1,3,4-oxadiazole triazole. The compound with a novel structure having selective HDAC6 inhibitory activity is represented by the following chemical formula I. [Chemical formula I] JPEG2025523127000047.jpg3086

Description

Technical Field

[0001] The present invention relates to a compound having a novel structure with histone deacetylase 6 (HDAC6) inhibitory activity, a stereoisomer thereof, a pharmaceutically acceptable salt thereof, its use in the manufacture of a prophylactic or therapeutic agent, a pharmaceutical composition containing the same, a prophylactic or therapeutic method thereof, and a method for producing the same.

Background Art

[0002] Post-translational modifications such as acetylation in cells are very important regulatory modules in biological processes and are strictly controlled by a number of enzymes. Histones are the main proteins that make up chromatin, which serve as the axis around which DNA is wound and help with DNA condensation. Also, the balance between histone acetylation and deacetylation plays a very important role in gene expression. Histone deacetylases (HDACs) are enzymes that remove the acetyl group from the lysine residue of histone proteins that make up chromatin, are associated with gene silencing, and are known to induce cell cycle arrest, inhibition of angiogenesis, immune regulation, cell death, etc. (Hassig et al., Curr. Opin. Chem. Biol. 1997, 1, 300-308). In addition, it has been reported that inhibition of the enzymatic function of HDAC induces the death of cancer cells by reducing the activity of factors related to the survival of cancer cells in vivo and activating factors related to the death of cancer cells (Warrell et al., J. Natl. Cancer Inst. 1998, 90, 1621-1625). In humans, 18 HDACs are known and are classified into four classes based on their homology to yeast HDACs. At this time, the 11 HDACs that use zinc as a cofactor are divided into three groups: Class I (HDAC1, 2, 3, 8), Class II (IIa: HDAC4, 5, 7, 9, IIb: HDAC6, 10), and Class IV (HDAC11). Furthermore, the seven HDACs of Class III (SIRT1-7) use NAD+ as a cofactor instead of zinc (Bolden et al., Nat. Rev. Drug Discov. 2006, 5(9), 769-784).

[0003] Various HDAC inhibitors are in preclinical or clinical development stages, but so far only non-selective HDAC inhibitors are known as anti-cancer drugs. Vorinostat (SAHA) and romidepsin (FK228) are approved as therapeutic agents for cutaneous T-cell lymphoma, and panobinostat (LBH-589) is approved as a therapeutic agent for multiple myeloma. However, in the case of non-selective HDAC inhibitors, it is generally known that they cause side effects such as fatigue and nausea at high doses (Piekarz et al., Pharmaceuticals 2010, 3, 2751-2767). These side effects have been reported to be caused by the inhibition of Class I HDACs, and due to these side effects and others, non-selective HDAC inhibitors have been restricted in drug development in other fields of anti-cancer drugs (Witt et al., Cancer Letters 277, (2009), 8-21). On the one hand, there are reports that in the case of selective Class II HDAC inhibition, the toxicity seen in Class I HDAC inhibition does not appear. When developing a selective HDAC inhibitor, side effects such as toxicity due to non-selective HDAC inhibition can be resolved, and selective HDAC inhibitors may be developed as effective therapeutic agents for various diseases (Matthias et al., Mol. Cell. Biol. 2008, 28, 1688 - 1701). HDAC6, one of the Class IIb HDACs, mainly exists in the cytoplasm and is known to be involved in the deacetylation of a number of non-Histone substrates (such as HSP90, cortactin) including tubulin protein (Yao et al., Mol. Cell 2005, 18, 601 - 607). HDAC6 has two catalytic domains, and the C-terminal zinc finger domain can bind to ubiquitinated protein. Since HDAC6 has a number of non-Histone proteins as substrates, it is known to play an important role in various diseases such as cancer, inflammatory diseases, autoimmune diseases, neurological diseases, and neurodegenerative disorders (Santo et al., Blood 2012 119, 2579 - 2589; Vishwakarma et al., International Immunopharmacology 2013, 16, 72 - 78; Hu et al., J. Neurol. Sci. 2011, 304, 1 - 8).

[0004] A structural feature common to various HDAC inhibitors is that, like the structure of vorinostat below, it is composed of a cap group, a linker, and a zinc binding group (ZBG). Many researchers have studied the inhibitory activity and selectivity for enzymes through structural modifications of the cap group and the linker. Among these, the zinc binding group is known to play a more important role in enzyme inhibitory activity and selectivity (Wiest et al., J. Org. Chem. 2013 78:5051 - 5055; Methot et al., Bioorg. Med. Chem. Lett. 2008, 18, 973 - 978). [Chemical formula] Most of the said zinc binding groups are hydroxamic acid or benzamide. Among these, hydroxamic acid derivatives exhibit a strong HDAC inhibitory effect but have problems of low bioavailability and serious off - target activity. In the case of benzamide, since it contains aniline, there is a risk of producing toxic metabolites in vivo (Woster et al., Med. Chem. Commun. 2015, online publication). Therefore, for the treatment of cancer, inflammatory diseases, autoimmune diseases, neurological diseases, and neurodegenerative disorders, etc., there is a need to develop a selective HDAC6 inhibitor with a zinc binding group that has no side effects and improved bioavailability, different from non - selective inhibitors with side effects. [Prior art documents] [Patent documents]

[0005] International Publication Patent Gazette WO2011 / 091213 (published on July 28, 2011): ACY-1215 International Publication Patent Gazette WO2011 / 011186 (published on January 27, 2011): Tubastatin International Publication Patent Gazette WO2013 / 052110 (published on April 11, 2013): Sloan-K International Publication Patent Gazette WO2013 / 041407 (published on March 28, 2013): Cellzome International Publication Patent Gazette WO2013 / 134467 (published on September 12, 2013): Kozi International Publication Patent Gazette WO2013 / 008162 (published on January 17, 2013): Novartis International Publication Patent Gazette WO2013 / 080120 (published on June 6, 2013): Novartis International Publication Patent Gazette WO2013 / 066835 (published on May 10, 2013): Tempero International Publication Patent Gazette WO2013 / 066838 (published on May 10, 2013): Tempero International Publication Patent Gazette WO2013 / 066833 (published on May 10, 2013): Tempero International Publication Patent Gazette WO2013 / 066839 (published on May 10, 2013): Tempero

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a compound having selective HDAC6 inhibitory activity, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. Another object of the present invention is to provide a pharmaceutical composition containing a compound having selective HDAC6 inhibitory activity, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. Another object of the present invention is to provide a method for producing the same. Another object of the present invention is to provide a pharmaceutical composition for preventing or treating HDAC6-mediated diseases. Another object of the present invention is to provide its use for the manufacture of a medicament for the prevention or treatment of HDAC6-mediated diseases. Another object of the present invention is to provide a method for preventing or treating an HDAC6-mediated disease, which comprises administering a therapeutically effective amount of the compound, its stereoisomer or its pharmaceutically acceptable salt. Another object of the present invention is to provide its prophylactic or therapeutic use against HDAC6-mediated diseases. [Means for Solving the Problems]

[0007] The present inventors have discovered an oxadiazole compound having histone deacetylase 6 (HDAC6) inhibitory activity, and completed the present invention by using this for the prevention or treatment of HDAC6-mediated diseases. Hereinafter, this will be specifically described. All combinations of various elements disclosed in the present invention belong to the scope of the present invention. Also, the scope of the present invention is not limited by the details of the following description.

[0008] The compound represented by Compound I (1) The present invention provides a 1,3,4-oxadiazole triazole compound represented by the following Chemical Formula I, its stereoisomer, or its pharmaceutically acceptable salt. [Chemical Formula I] [Chemical Structure] In the above Chemical Formula I, X1, X2, X3 and X4 are each independently CH or N, and at least one of X1 to X4 is N. R1 is CF2H. L is C1-C2 alkylene. R2 is H or C1-C5 alkyl. A is C6-C12 aryl or 5- to 6-membered heteroaryl, wherein at least one of the Hs of C6-C12 aryl is substituted with a halogen. R3 is -NR4R5 or

Chemical formula

[0009] In the present invention, the halogen may be F, Cl, Br or I. In the present invention, Cx-Cy (where x and y are each an integer of 1 or more) may indicate the carbon number range contained in the substituent. In the present invention, alkylene means a divalent functional group derived from a straight-chain or branched-chain saturated hydrocarbon. For example, C1 alkylene may be methylene. In the present invention, aryl means a monocyclic aromatic or polycyclic aromatic functional group consisting only of carbon and hydrogen. For example, aryl may include phenyl, naphthyl, etc. In the present invention, heteroaryl means a monocyclic or polycyclic heterocyclic ring in which at least one or more carbons are substituted with heteroatoms. Examples of heteroatoms include nitrogen (N), oxygen (O), sulfur (S), etc. When heteroaryl contains two or more heteroatoms, the two or more heteroatoms may be the same or different. For example, heteroaryl may include thiophenyl, pyridinyl or thiazolyl. In the present invention, haloalkyl means a functional group in which at least one of the Hs of alkyl, which is a monovalent functional group derived from a straight-chain or branched-chain saturated hydrocarbon, is substituted with a halogen. For example, haloalkyl may include -CF3, -CH2-CF3, -CHF-CH3, -CF2H, -CFH2, etc. In the present invention

Chemical formula

[0010] (2) In the above (1), X1, X3 and X4 of the chemical formula I are each CH, and X2 may be N. (3) In the above (1) or (2), A of the chemical formula I may be phenyl in which one hydrogen is substituted by halogen, or a 5- to 6-membered heteroaryl containing at least one or more heteroatoms selected from N and S. (4) In any of the above (1) to (3), the 5- to 6-membered heteroaryl may contain thiophenyl, pyridinyl or thiazolyl. (5) In any of the above (1) to (4), a 1,3,4-oxadiazole triazole compound according to the present invention can be provided. At this time, X1, X3 and X4 of the chemical formula I are each CH, X2 is N, L is C1 alkylene, R1, R2, A and R3 are the same as defined in the chemical formula I above.

[0011] (6) In the above (1), a 1,3,4-oxadiazole triazole compound according to the present invention can be provided. At this time, X1 to X4, R1, L and R2 of the chemical formula I are the same as defined in the chemical formula I above, A is C6 aryl, and at least one of the H of C6 aryl is substituted by halogen, R3 is -NR4R5 or

Chemical formula

Chemical formula

Chemical formula

[0012] In the present invention, a pharmaceutically acceptable salt means a salt commonly used in the pharmaceutical industry. For example, inorganic ion salts produced from calcium, potassium, sodium, magnesium, etc., inorganic acid salts produced from hydrochloric acid, nitric acid, phosphoric acid, bromic acid, iodic acid, perchloric acid, or sulfuric acid, etc., organic acid salts produced from acetic acid, trifluoroacetic acid, citric acid, maleic acid, succinic acid, oxalic acid, benzoic acid, tartaric acid, fumaric acid, mandelic acid, propionic acid, lactic acid, glycolic acid, gluconic acid, galacturonic acid, glutamic acid, glutaric acid, glucuronic acid, aspartic acid, ascorbic acid, carboxylic acid, vanillic acid, hydroiodic acid, etc., sulfonic acid salts produced from methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, or naphthalenesulfonic acid, etc., amino acid salts produced from glycine, arginine, lysine, etc., and amine salts produced from trimethylamine, triethylamine, ammonia, pyridine, picoline, etc. are available. However, the types of salts meant in the present invention are not limited by these exemplified salts. Preferred salts in the present invention include hydrochloric acid, trifluoroacetic acid, citric acid, bromic acid, maleic acid, phosphoric acid, sulfuric acid, tartaric acid, etc. As an example, the pharmaceutically acceptable salt of the present invention may be the salt of Compound 1 in the present specification. The 1,3,4-oxadiazole triazole compound of the present invention can contain one or more asymmetric carbons, and thus can exist as a racemate, a racemic mixture, a single enantiomer, a mixture of diastereomers, and each diastereomer. These isomers of the compound represented by Chemical Formula I can be separated by conventional techniques, for example, by separation such as column chromatography or HPLC. Alternatively, each stereoisomer of the compound represented by Chemical Formula I can be stereospecifically synthesized using optically pure starting materials and / or reagents of known sequences. In the present invention, the "stereoisomer" includes diastereomers and optical isomers, and the optical isomers include not only enantiomers but also all mixtures of enantiomers and racemates.

[0013] (9) The 1,3,4-oxadiazole triazole compound according to the present invention may be any one selected from the compounds shown in Table 1 below.

Table 1-1

Table 1-2

[0014] Method for producing the compound of Chemical Formula I A preferred method for producing the 1,3,4-oxadiazole triazole compound, its stereoisomer, or its pharmaceutically acceptable salt according to the present invention is according to Reaction Scheme 1 and Reaction Scheme 2, and production methods modified at a level obvious to those skilled in the art are also included herein. Hereinafter, in Reaction Schemes 1 and 2, those represented by the same symbols as Chemical Formula I and not specifically described may be the same as the definition of Chemical Formula I, so duplicate explanations are omitted. [Reaction Scheme 1]

Chemical Formula

Chemical Formula

[0015] According to the above Reaction Scheme 2, after producing compound 2-3 having a trimethylsilane protecting group through C-C coupling (Sonogashira coupling) of halide compound 2-1 and compound 2-2 having a triple bond, the trimethylsilane protecting group can be removed to produce compound 2-4 having an aldehyde structure. Compound 2-5 having a triazole structure can be produced by the click reaction of compound 2-4 and compound 1-2, and compound 2-6 can be produced by a reductive amination reaction. The 1,3,4-oxadiazole triazole compound according to the present invention can be produced by the above-described Reaction Schemes 1 and 2.

[0016] Diseases mediated by histone deacetylase 6 include cancer, inflammatory diseases, autoimmune diseases, neurological or neurodegenerative diseases, specifically lung cancer, colon cancer, breast cancer, prostate cancer, liver cancer, brain cancer, ovarian cancer, gastric cancer, skin cancer, pancreatic cancer, glioblastoma, glioblastoma carcinoma, leukemia, lymphoma, multiple myeloma, solid cancer, Wilson's disease, spinocerebellar ataxia, prion disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, amyloidosis, Alzheimer's disease, alcoholic liver disease, spinal muscular atrophy, rheumatoid arthritis, or osteoarthritis, and also include symptoms or diseases related to abnormal functions of histone deacetylases. Examples of histone deacetylase-mediated diseases include infectious diseases, neoplasms, endocrine, nutritional and metabolic diseases, mental and behavioral disorders, neurological diseases, eye and adnexa diseases, cardiovascular diseases, respiratory diseases, digestive diseases, skin and subcutaneous tissue diseases, musculoskeletal and connective tissue diseases, or congenital malformations, deformations and chromosomal abnormalities. The endocrine, nutritional and metabolic diseases are Wilson's disease, amyloidosis, or diabetes; the mental and behavioral disorders are depression or Rett syndrome; the neurological diseases are central nervous system atrophy, neurodegenerative diseases, movement disorders, neuropathies, motor neuron diseases, or demyelinating diseases of the central nervous system; the eye and adnexa diseases are uveitis; the skin and subcutaneous tissue diseases are psoriasis; the musculoskeletal and connective tissue diseases are rheumatoid arthritis, osteoarthritis, or systemic lupus erythematosus; the congenital malformations, deformations and chromosomal abnormalities are autosomal dominant polycystic kidney; the infectious disease is prion disease; the neoplasm is a benign tumor or a malignant tumor; the cardiovascular disease is atrial fibrillation or stroke; the respiratory disease is asthma; the digestive disease may be alcoholic liver disease, inflammatory bowel disease, Crohn's disease, or ulcerative colitis. The pharmaceutically acceptable salts are the same as those described in the pharmaceutically acceptable salts of the 1,3,4-oxadiazole triazole compounds according to the present invention.

[0017] The pharmaceutical composition of the present invention may further contain one or more pharmaceutically acceptable carriers in addition to the 1,3,4-oxadiazole triazole compound, its stereoisomer, or its pharmaceutically acceptable salt for administration. At this time, the pharmaceutically acceptable carrier can be physiological saline, sterilized water, Ringer's solution, buffered physiological saline, dextrose solution, maltodextrin solution, glycerol, ethanol, and one or more of these components can be mixed and used. If necessary, other ordinary additives such as antioxidants, buffers, and bacteriostatic agents can also be added. Further, a diluent, a dispersant, a surfactant, a binder, and a lubricant can be added, and it can be formulated into injection dosage forms such as aqueous solutions, suspensions, emulsions, pills, capsules, granules, or tablets. Therefore, the composition of the present invention may be a patch, a liquid, a pill, a capsule, a granule, a tablet, a suppository, or the like. These formulations can be manufactured by ordinary methods used for formulation in the art or by the methods disclosed in Remington's Pharmaceutical Science (latest edition), Mack Publishing Company, Easton PA, and can be formulated into various formulations depending on each disease or component. The composition of the present invention can be administered orally or parenterally (for example, intravenously, subcutaneously, intraperitoneally, or topically applied) according to the desired method, and the dosage range varies depending on the patient's body weight, age, gender, health condition, diet, administration time, administration method, excretion rate, and disease severity, etc. The daily dosage of the compound represented by Chemical Formula I of the present invention is about 1 to 1000 mg / kg, preferably about 5 to 100 mg / kg, and can be administered once to several times a day. The aforementioned pharmaceutical composition of the present invention may further contain one or more active ingredients showing the same or similar medicinal effects in addition to the compound represented by Chemical Formula I described above or the 1,3,4-oxadiazole triazole compound, its stereoisomer, or its pharmaceutically acceptable salt listed in Table 1. The present invention provides a method for preventing or treating a Histone deacetylase 6-mediated disease, which comprises administering a therapeutically effective amount of a compound represented by the aforementioned chemical formula I, or a 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1, its stereoisomers, or a pharmaceutically acceptable salt thereof. The term "therapeutically effective amount" as used in the present invention can indicate the amount of a compound represented by the aforementioned chemical formula I, or a 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1, which is effective for preventing or treating a Histone deacetylase 6-mediated disease.

[0018] In addition, the present invention provides a method for selectively inhibiting HDAC6 by administering a compound represented by the aforementioned chemical formula I, or a 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1, its stereoisomers, or a pharmaceutically acceptable salt thereof, to mammals including humans. The method for preventing or treating histone deacetylase 6-mediated diseases of the present invention involves administering a compound represented by the aforementioned chemical formula I or a 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1, which not only addresses the disease itself before the manifestation of symptoms but can also include inhibiting or avoiding those symptoms. In the management of diseases, the prophylactic or therapeutically effective dosage of a specific active ingredient varies depending on the nature and severity of the disease or condition, and the route by which the active ingredient is administered. The dosage and frequency of dosing vary according to the age, weight, and response of the individual patient. Suitable dosages and usage can be easily selected by those with ordinary knowledge in the art, who naturally consider such factors. Further, the method for preventing or treating histone deacetylase 6-mediated diseases of the present invention can further include administering a therapeutically effective amount of an additional active formulation useful for treating the disease, together with the compound represented by the aforementioned chemical formula I or the 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1, and the additional active formulation can exhibit a synergistic or supplementary effect with the compound of formula I.

[0019] The present invention also aims to provide the use of a compound represented by the aforementioned chemical formula I or a 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1, its stereoisomers, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for preventing or treating histone deacetylase 6-mediated diseases. The compound represented by the aforementioned chemical formula I or the 1,3,4-oxadiazole triazole compound containing the compounds listed in Table 1 for manufacturing a medicament can be mixed with acceptable adjuvants, diluents, carriers, etc., and manufactured as a combined formulation together with other active formulations, and can have a synergistic effect of the active ingredients. The matters referred to as the use, composition, and treatment method of the present invention can be applied in the same manner as long as they do not conflict with each other.

Advantages of the Invention

[0020] The 1,3,4-oxadiazole triazole compound of the present invention, its stereoisomers, or its pharmaceutically acceptable salts can selectively inhibit HDAC6 and have an excellent preventive or therapeutic effect on diseases related to Histone deacetylase 6 activity.

Mode for Carrying Out the Invention

[0021] Example 1: Synthesis of Compound 1, 2-(Difluoromethyl)-5-(6-((4-(5-((4-Methylpiperidin-1-yl)methyl)thiophen-2-yl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4-oxadiazole [Step 1] Synthesis of 2-(6-(Azidomethyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4-oxadiazole

Chemical formula

[0022] [Step 2] Synthesis of 5-((Trimethylsilyl)ethynyl)thiophene-2-carbaldehyde

Chemical formula

[0023] [Step 3] Synthesis of 5-Ethynylthiophene-2-carbaldehyde [Chemical formula] A solution of 5-((trimethylsilyl)ethynyl)thiophene-2-carbaldehyde (0.550 g, 2.640 mmol) and potassium carbonate (1.094 g, 7.919 mmol) in methanol (5 mL) prepared at room temperature was stirred at the same temperature for 18 h. Water was poured into the reaction mixture, and the mixture was extracted with dichloromethane. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The concentrate was purified and concentrated by column chromatography (SiO2, 12 g cartridge; ethyl acetate / hexane = 0% - 20%) to give 5-ethynylthiophene-2-carbaldehyde (0.300 g, 83.5%) as a pale yellow solid.

[0024] [Step 4] Synthesis of 5-(1-((5-(5-(Difluoromethyl)-1,3,4-oxadiazol-2-yl)pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)thiophene-2-carbaldehyde

Chem.

[0025] [Step 5] Synthesis of Compound 1

Chem.

[0026] 1 1H NMR (400 MHz, CD3OD) δ 9.27 (d, J = 1.6 Hz, 1H), 8.53 (dd, J = 8.2, 2.2 Hz, 1H), 8.46 (s, 1H), 7.62 (d, J = 8.4 Hz, 1H), 7.40 (d, J = 3.6 Hz, 1H), 7.26 (t, J = 51.4 Hz, 1H), 7.20 (d, J = 3.2 Hz, 1H), 6.71 (s, 2H), 5.91 (s, 2H), 4.27 (s, 2H), 2.70 (t, J = 12.6 Hz, 2H), 1.86 (d, J = 12.8 Hz, 2H), 1.62 (s, 1H); LRMS (ES) m / z 472.3 (M + +1)

[0027] Examples 7 to 16 Among the methods for producing Compound 1 according to Example 1, Compounds 7 to 16 were synthesized through substantially the same steps as the method for producing Compound 1, except that the reactants shown in Table 2 below were used instead of 4-methylpiperidine in Step 5. [Table 2]

[0028] Example 2: Synthesis of Compound 2, 2-(6-((4-(5-(azetidin-1-ylmethyl)pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4-oxadiazole [Step 1] Synthesis of 6-((trimethylsilyl)ethynyl)nicotinaldehyde [Chemical formula] 6-Bromonicotinaldehyde (1.000 g, 5.376 mmol), bis(triphenylphosphine)palladium dichloride (0.151 g, 0.215 mmol), copper(I / II) iodide (0.102 g, 0.538 mmol), and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos, 0.124 g, 0.215 mmol) were dissolved in triethylamine (15 mL). Trimethylsilylacetylene (0.836 mL, 5.914 mmol) was added at room temperature, and the mixture was stirred at the same temperature for 18 hours. The reaction mixture was filtered through a Celite pad to remove solids, and the filtrate was concentrated under reduced pressure to remove the solvent. The concentrate was purified and concentrated by column chromatography (SiO 2, 24 g cartridge; ethyl acetate / hexane = 0% to 50%) to obtain 6-((trimethylsilyl)ethynyl)nicotinaldehyde (0.400 g, 36.6%) as a pale brown solid.

[0029] [Step 2] Synthesis of 6-ethynylnicotinaldehyde [Chemical formula] A solution of 6-((trimethylsilyl)ethynyl)nicotinaldehyde (0.370 g, 1.820 mmol) and potassium carbonate (0.755 g, 5.459 mmol) prepared in methanol (5 mL) at room temperature was stirred at the same temperature for 18 h. Water was poured into the reaction mixture, and the mixture was extracted with dichloromethane. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The concentrate was purified and concentrated by column chromatography (SiO2, 12 g cartridge; ethyl acetate / hexane = 0% - 40%) to obtain 6-ethynylnicotinaldehyde (0.200 g, 83.8%) as a beige solid.

[0030] [Step 3] Synthesis of 6-(1-((5-(5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)nicotinaldehyde [Chemical formula] 6-Ethynylnicotinaldehyde (0.100 g, 0.763 mmol) prepared in Step 2 and 2-(6-(azidomethyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4-oxadiazole (0.192 g, 0.763 mmol) prepared in Step 1 of Example 1 were dissolved in tert-butanol (2 mL) / water (2 mL) at room temperature, and sodium ascorbate (1.00 M solution, 0.076 mL, 0.076 mmol) and copper(I / II) sulfate (1.00 M solution, 0.038 mL, 0.038 mmol) were added. The mixture was stirred at the same temperature for 18 hours. A saturated aqueous ammonium chloride solution was poured into the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The concentrate was purified and concentrated by column chromatography (SiO2, 12 g cartridge; ethyl acetate / hexane = 0% - 50%) to obtain 6-(1-((5-(5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)nicotinaldehyde (0.180 g, 61.6%) as a pale yellow solid.

[0031] [Step 4] Synthesis of Compound 2 [Chemical formula] 6-(1-((5-(5-(Difluoromethyl)-1,3,4-oxadiazol-2-yl)pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)nicotinaldehyde (0.040 g, 0.104 mmol) prepared in Step 3 and azetidine hydrochloride (0.020 g, 0.209 mmol) were dissolved in dichloromethane (1 mL) at room temperature, and sodium triacetoxyborohydride (0.111 g, 0.522 mmol) was added. The mixture was stirred at the same temperature for 18 hours. A saturated aqueous sodium hydrogen carbonate solution was poured into the reaction mixture, and the mixture was extracted with dichloromethane. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The concentrate was purified by column chromatography (SiO2, 4G cartridge; purified and concentrated with dichloromethane / methanol = 100% - 80%), and 2-(6-((4-(5-(azetidin-1-ylmethyl)pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4-oxadiazole (0.021 g, 47.4%) was obtained as a white solid.

[0032] Examples 3 to 6 and 17 Among the methods for preparing Compound 2 according to Example 2, Compounds 3 - 6 and 17 according to Examples 3 - 6 and 17 were synthesized through substantially the same steps as the method for preparing Compound 2, except that the reactants in Table 3 below were used instead of azetidine in Step 4.

Table 3

[0033] Examples 18 to 39, 41 and 42 Among the methods for preparing Compound 2 according to Example 2, in Step 3, instead of 6-ethynylnicotinaldehyde, the product obtained by reacting Reactant 1 in Table 4 with 2-(6-(azidomethyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4-oxadiazole was reacted with Reactant 2 in Table 4 below through substantially the same steps as Step 4 of Example 2 to prepare Compounds 18 - 39, 41 and 42 according to Examples 18 - 39, 41 and 42, respectively.

Table 4 - 1

Table 4 - 2

[0034] Example 40: Synthesis of Compound 40, 2-(difluoromethyl)-5-(6((4-(2-(piperidin-1-ylmethyl)thiazol-4-yl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4-oxadiazole Among the methods for producing Compound 2 according to Example 2, in Step 3, instead of 6-ethynylnicotinaldehyde, 4-ethynylthiazole-2-carbaldehyde was reacted with 2-(6-(azidomethyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4-oxadiazole to obtain a product, which was then reacted with piperidine through substantially the same steps as in Step 4 of Example 2 to produce Compound 40 of Example 40 (yield 61%).

[0035] Compounds 2 to 42 obtained as the final products according to Examples 2 to 42 and their analytical data are shown in Table 5 below. [Table 5-1] [Table 5-2] [Table 5-3] [Table 5-4] [Table 5-5] [Table 5-6] [Table 5-7] [Table 5-8] [Table 5-9] [Table 5-10]

[0036] Activity measurement and analysis protocol of the compound of the present invention Experimental Example 1. Search for HDAC Enzyme Activity Inhibition (in vitro) In order to confirm the selectivity of the 1,3,4-oxadiazole triazole compound of the present invention for HDAC6 by the HDAC1 and HDAC6 enzyme activity inhibition experiments, experiments were conducted. HDAC enzyme activity was measured using the HDAC Fluorimetric Drug Discovery Kit (BML-AK511,516) from Enzo Life Science. For the HDAC1 enzyme activity test, human recombinant HDAC1 (BML-SE456) was used as the enzyme source and Fluor de Lys®-“SIRT1 (BNL-KI177) was used as the substrate. After dispensing the compound diluted 5-fold into a 96-well plate, 0.3 μg of the enzyme and 10 μM of the substrate were added per well, and after reacting at 30 °C for 60 minutes, Fluor de Lys® Developer II (BML-KI176) was added and the reaction was allowed to proceed for 30 minutes. After completion, the fluorescence value (Ex360, Em460) was measured using a multi-plate reader (Flexstation 3, Molecular Device). The HDAC6 enzyme was experimented using human recombinant HDAC6 (382180) from Calbiochem according to the same protocol as the HDAC1 enzyme activity test method. The final result values were calculated for each IC 50 value using the GraphPad Prism 4.0 program. [Table 6]

[0037] As described in Table 6 above, it was confirmed that the 1,3,4-oxadiazole triazole compound of the present invention, its stereoisomers, or its pharmaceutically acceptable salts exhibited excellent selective HDAC6 inhibitory activity of about 1048 to about 3731 times from the results of the activity inhibition tests against HDAC1 and HDAC6.

[0038] Experimental Example 2. Analysis of the effect of an HDAC6-specific inhibitor on mitochondrial axonal transport (in vitro) Through the analysis of the effect of an HDAC6-specific inhibitor on mitochondrial axonal transport, it was confirmed whether the 1,3,4-oxadiazole triazole compound of the present invention selectively inhibits HDAC6 activity and increases the acetylation of Tubulin, which is a major substrate of HDAC6, thereby showing an improvement effect on the migration speed of mitochondria decreased by Amyloid-beta treatment within the axons of nerve cells. An experiment was conducted. Hippocampal neurons from Sprague-Dawley (SD) rat fetuses on the 17th to 18th day of gestation (E17-18) were cultured for 7 days in an imaging culture vessel coated with an extracellular matrix, and treated with Amyloid-beta protein sections at a concentration of 1 M. After 24 hours, the compound was treated on the 8th day of in-vessel culture, and after 3 hours, MitoTracker Red CMXRos (Life Technologies, NY, USA) was treated for the final 5 minutes to stain the mitochondria. The axonal transport of the stained neuronal mitochondria was imaged at 1-second intervals for 1 minute using a confocal microscope (Leica SP8; Leica microsystems, UK), and the moving speed per second of each mitochondrion was measured using the IMARIS analysis program (BITPLANE, Zurich, Switzerland). As a result, for the improvement efficacy shown by the 1,3,4-oxadiazole triazole compound of the present invention, its stereoisomers, or its pharmaceutically acceptable salts on the mitochondrial axonal transport rate, after setting a section where the mitochondrial migration speed was significantly decreased compared to the vehicle in the amyloid beta treatment group, after normalizing with vehicle 100% and the amyloid beta treatment group 0%, it was confirmed that the speed distribution display of the compound was shown as *, 0% - 50%; **, 50% - 100%; ***, >100%.

[0039]

Table 7

Claims

1. A 1,3,4-oxadiazole triazole compound represented by the following chemical formula I, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof: [Chemical formula 1] 【Chemical 1】 In the above chemical formula I, X 1 , X 2 , X 3 and X 4 are each independently CH or N, and at least one of X 1 to X 4 is N, R 1 is CF 2 H and L is C1-C2 alkylene, R 2 is H or C1-C5 alkyl, A is C6-C12 aryl or a 5- or 6-membered heteroaryl, wherein at least one of the Hs of C6-C12 aryl is substituted with a halogen, R 3 is - NR 4 R 5 or 【Chemical 2】 and R 4 and R 5 are each independently H or C1-C6 alkyl, R 6 and R 7 are each independently H, halogen, C1-C6 alkyl, or C1-C6 haloalkyl, n and m are each independently 1 or 2.

2. X of the chemical formula I 1 , X 3 and X 4 are each CH, and X 2 is N, L is C1 alkylene, R 1 、R 2 、A and R 3 are the same as the definitions in claim 1, respectively. A 1,3,4-oxadiazole triazole compound represented by Claim 1, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

3. X of the chemical formula I 1 ~X 4 , R 1 , L and R 2 are the same as defined in claim 1, A is C6 aryl, wherein at least one of the Hs of C6 aryl is substituted with a halogen, R 3 is -NR 4 R 5 or 【Chemical Formula 3】 and R 4 and R 5 are each independently C1-C6 alkyl, R 6 and R 7 are each independently H or C1-C6 alkyl, n and m are each independently 1 or 2, A 1,3,4-oxadiazole triazole compound represented by Claim 1, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

4. X of the chemical formula I 1 ~X 4 , R 1 , L and R 2 are the same as defined in claim 1, A is a 6-membered heteroaryl, R 3 is [Chemical Formula 4] and R 6 and R 7 are each independently H or C1-C6 alkyl, n and m are each independently 1 or 2, A 1,3,4-oxadiazole triazole compound represented by Claim 1, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

5. X of the formula (I) above 1 ~X 4 , R 1 , L and R 2 are the same as defined in claim 1, A is a 5-membered heteroaryl, R 3 is - NR 4 R 5 or [Chemical Formula 5] and R 4 and R 5 are each independently C1-C6 alkyl, R 6 and R 7 are each independently H, halogen, C1-C6 alkyl, or C1-C6 haloalkyl, n and m are each independently 1 or 2, A 1,3,4-oxadiazole triazole compound represented by Claim 1, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

6. A 1,3,4-oxadiazole triazole compound, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, selected from the group consisting of the compounds shown in the following table: 【Table 1-1】 【Table 1-2】

7. A pharmaceutical composition for preventing or treating a histone deacetylase-mediated disease, comprising as an active ingredient a 1,3,4-oxadiazole triazole compound, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof according to any one of Claims 1 to 6.

8. The histone deacetylase-mediated disease is an infectious disease; a neoplasm; an endocrine, nutritional and metabolic disease; a mental and behavioral disorder; a neurological disease; an eye and adnexa disease; a cardiovascular disease; a respiratory disease; a digestive disease; a skin and subcutaneous tissue disease; a musculoskeletal and connective tissue disease; or a congenital malformation, deformation and chromosomal abnormality. The pharmaceutical composition according to Claim 7.

9. ​ The endocrine, nutritional and metabolic diseases are Wilson's disease, amyloidosis, or diabetes, The mental and behavioral disorders are depression or Rett syndrome, The nervous diseases are central nervous system atrophy, neurodegenerative diseases, movement disorders, neuropathy, motor neuron diseases, or demyelinating diseases of the central nervous system, The eye and adnexa diseases are uveitis, The skin and subcutaneous tissue diseases are psoriasis, The musculoskeletal and connective tissue diseases are rheumatoid arthritis, osteoarthritis, or systemic lupus erythematosus, The congenital malformations, deformations and chromosomal abnormalities are autosomal dominant polycystic kidney disease, The infectious diseases are prion diseases, The neoplasms are benign tumors or malignant tumors, The cardiovascular diseases are atrial fibrillation or stroke, The respiratory diseases are asthma, The digestive diseases are alcoholic liver disease, inflammatory bowel disease, Crohn's disease, or ulcerative colitis, The pharmaceutical composition according to claim 8.

10. Use of a 1,3,4-oxadiazole triazole compound, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 6 for the prevention or treatment of histone deacetylase-mediated diseases.

11. Use of a 1,3,4-oxadiazole triazole compound, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 6 for the manufacture of a medicament for the prevention or treatment of histone deacetylase-mediated diseases.

12. A method for the prevention or treatment of histone deacetylase-mediated diseases, comprising administering a therapeutically effective amount of a 1,3,4-oxadiazole triazole compound, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 6.

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