Oxadiazole derivative compounds, and the pharmaceutical composition comprising the same

Abstract

The present invention relates to a novel compound having a histone deacetylase 6 (HDAC6) inhibitory activity, stereoisomers thereof, pharmaceutically acceptable salts thereof, a use thereof for preparing a medicament, a pharmaceutical composition comprising the same, a preventive or therapeutic method thereof, and a method for preparing novel 1,3,4-oxadiazole oxetane derivative.

Description

[0001] OXADIAZOLE DERIVATIVE COMPOUNDS, AND THE PHARMACEUTICAL

[0002] COMPOSITION COMPRISING THE SAME

[0003] Technical Field

[0004] The present invention relates to novel oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof; a pharmaceutical composition containing the oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof; a use of the oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof in preparing a therapeutic drug; a method for preventing or treating diseases by administering the oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof; and a method for preparing the oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0005] Background

[0006] In cells, a post-translational modification such as acetylation serves as a very important regulatory module at the hub of biological processes, and is also strictly controlled by a number of enzymes. As a core protein constituting chromatin, histone functions as an axis, around which DNA winds, and thus helps a DNA condensation. In addition, a balance between acetylation and deacetylation of histone plays a very important role in gene expression.

[0007] As an enzyme for removing an acetyl group from lysine residue of histone protein, which constitutes chromatin, histone deacetylase (HD AC) is known to be associated with gene silencing and induce a cell cycle arrest, angiogenic inhibition, immunoregulation, apoptosis, etc. (Hassig et al., Curr. Opin. Chem. Biol. 1997, 1, 300-308). Moreover, it is reported that the inhibition of HDAC enzyme functions induces cancer cells into committing apoptosis for themselves by lowering an activity of cancer cell survival -related factors and activating cancer cell death-related factors in the body (Warrell et al., J. Natl. Cancer Inst. 1998, 90, 1621-1625).

[0008] For humans, 18 HDACs are known and classified into four classes according to homology with yeast HDAC. In this case, eleven HDACs using zinc as a cofactor may be divided into three groups: Class I (HDAC1, 2, 3, 8), Class II (Ila: HDAC4, 5, 7, 9; lib: HDAC6, 10) and Class IV (HDAC11). Further, seven HDACs of Class III (SIRT 1-7) use NAD+ as a cofactor instead of zinc (Bolden et al., Nat. Rev. Drug Discov. 2006, 5(9), 769-784).

[0009] Various HDAC inhibitors are now in a preclinical or clinical development stage, but only non-selective HDAC inhibitors have been known as an anti-cancer agent so far. Vorinostat (SAHA) and romidepsin (FK228) have obtained an approval as a therapeutic agent for cutaneous T-cell lymphoma, while panobinostat (LBH-589) has won an approval as a therapeutic agent for multiple myeloma. However, it is known that the non-selective HDAC inhibitors generally bring about side effects such as fatigue, nausea and the like at high doses (Piekarz et al., Pharmaceuticals 2010, 3, 2751-2767). It is reported that the side effects are caused by the inhibition of class I HDACs. Due to the side effects, etc., the non-selective HDAC inhibitors have been subject to restriction on drug development in other fields than an anticancer agent (Witt et al., Cancer Letters 277, (2009), 8-21).

[0010] Meanwhile, it is reported that the selective inhibition of class II HDACs would not show toxicity, which have occurred in the inhibition of class I HDACs. In case of developing the selective HDAC inhibitors, it would be likely to solve side effects such as toxicity, etc., caused by the non-selective inhibition of HDACs. Accordingly, there is a chance that the selective HDAC inhibitors may be developed as an effective therapeutic agent for various diseases (Matthias et al., Mol. Cell. Biol. 2008, 28, 1688-1701). HDAC6, one of the class lib HDACs, is known to be mainly present in cytoplasma and contain a tubulin protein, thus being involved in the deacetylation of a number of nonhistone substrates (HSP90, cortactin, etc.) (Yao et al., Mol. Cell 2005, 18, 601-607). HDAC6 has two catalytic domains, in which a zinc finger domain of C-terminal may bind to an ubiquitinated protein. HDAC6 is known to have a number of non-histone proteins as a substrate, and thus play an important role in various diseases such as cancer, inflammatory disease, autoimmune disease, neurological disease, neurodegenerative disorder and the like (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).

[0011] A structural feature that various HD AC inhibitors have in common is comprised of a cap group, a linker group and a zinc binding group (ZBG) as shown in a following structure of vorinostat. Many researchers have conducted a study on the inhibitory activity and selectivity with regard to enzymes through a structural modification of the cap group and the linker group. Out of the groups, it is known that the zinc binding group plays a more important role in the 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).

[0012] Ca Zinc Binding )

[0013] Most of said zinc binding group is comprised of hydroxamic acid or benzamide, out of which hydroxamic acid derivatives show a strong HDAC inhibitory effect, but have a problem with low bioavailability and serious off-target activity. Benzamide contains aniline, and thus has a problem in that it may produce toxic metabolites in vivo (Woster et al., Med. Chem. Commun. 2015, online publication).

[0014] Accordingly, unlike the non-selective inhibitors having side effects, there is a need to develop a selective HDAC6 inhibitor, which has a zinc binding group with improved bioavailability, while causing no side effects in order to treat cancer, inflammatory disease, autoimmune disease, neurological disease, neurodegenerative disorder and the like.

[0015] [Related Art Reference]

[0016] [Patent Documents]

[0017] (Patent Document 1) International Unexamined Patent Publication No. WO

[0018] 2011 / 091213

[0019] (Patent Document 2) International Unexamined Patent Publication No. WO

[0020] 2011 / 011186

[0021] (Patent Document 3) International Unexamined Patent Publication No. WO

[0022] 2013 / 052110

[0023] (Patent Document 4) International Unexamined Patent Publication No. WO

[0024] 2013 / 041407

[0025] (Patent Document 5) International Unexamined Patent Publication No. WO

[0026] 2013 / 134467

[0027] (Patent Document 6) International Unexamined Patent Publication No. WO

[0028] 2013 / 008162

[0029] (Patent Document 7) International Unexamined Patent Publication No. WO

[0030] 2013 / 080120

[0031] (Patent Document 8) International Unexamined Patent Publication No. WO

[0032] 2013 / 066835

[0033] (Patent Document 9) International Unexamined Patent Publication No. WO

[0034] 2013 / 066838 (Patent Document 10) International Unexamined Patent Publication No. WO 2013 / 066833

[0035] (Patent Document 11) International Unexamined Patent Publication No. WO 2013 / 066839

[0036] Detailed Description of the Invention

[0037] Technical Problem

[0038] An object of the present invention is to provide oxadiazole derivative compounds having a selective HDAC6 inhibitory activity, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0039] Another object of the present invention is to provide a pharmaceutical composition including oxadiazole derivative compounds having a selective HDAC6 inhibitory activity, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0040] Still another object of the present invention is to provide a method for preparing oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0041] Still another object of the present invention is to provide a pharmaceutical composition for preventing or treating HDAC6 activity-related diseases or degenerative brain diseases, including oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0042] Still another object of the present invention is to provide a use of oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof in preparing a medicament for preventing or treating HDAC6 activity-related diseases or degenerative brain diseases.

[0043] Still another object of the present invention is to provide a method for preventing or treating HDAC6 activity-related diseases or degenerative brain diseases, including administering a therapeutically effective amount of oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0044] Still another object of the present invention is to provide a use of oxadiazole derivative compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof in preventing or treating HDAC6 activity-related diseases or degenerative brain diseases.

[0045] Technical Solution

[0046] The present inventors have found an oxadiazole derivative compound having a histone deacetylase 6 (HDAC6) inhibitory activity and have used the same in inhibiting or treating HDAC6 activity-related diseases, thereby completing the present invention.

[0047] Hereinafter, the present invention will be described in more detail. All the combinations of various elements disclosed in the present invention fall within the scope of the present invention. In addition, it cannot be seen that the scope of the present invention is limited to the specific description below.

[0048] Compound

[0049] The present invention may provide a compound according to any one of (1) to (7) below, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0050] (1) A compound represented by formula I below, stereoisomers thereof or pharmaceutically acceptable salts thereof:

[0051] [Formula I] in above formula I,

[0052] XI to X4 are each independently N or CRx, in which three or more of Xi to X4 may not be N at the same time, and Rx is -H, F, Cl, Br or I;

[0053] Ri is -CXaH2, -C(Xa)2H, or -C(Xa)3, in which Xa is F, Cl, Br or I; and

[0054] R2 and R3 are each independently F, Cl, Br or I.

[0055] (2) The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to above (1): in above formula I,

[0056] Xi to X4 are each independently N or -CRx, in which three or more of Xi to X4 may not be N at the same time, and Rx is H or F;

[0057] Ri is -CXaFB or -C(Xa)2H, in which Xais F or Cl; and

[0058] R2 and R3 may be each independently F or Cl.

[0059] (3) The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to above (1) or (2): the compound represented by above formula I may be a compound represented by formula II:

[0060] [Formula II]

[0061] in above formula II,

[0062] X2 is N or CRx, in which Rxis H, F, Cl, Br or I;

[0063] Ri is -CXaFF, -C(Xa)2H, or -C(Xa)3, in which Xa is F, Cl, Br or I; and

[0064] R2 and R3 may be each independently F, Cl, Br or I.

[0065] (4) The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to above (1), (2) or (3): the compound represented by above formula I or II may be a compound represented by formula II- 1, II-2, II-3, or II-4 below.

[0066] [Formula II- 1]

[0067] [Formula II-2]

[0068]

[0069] In above formula II- 1, II-2, II-3, or II-4,

[0070] X2 is independently N or CRx in each formula, and Rx is H, F or Cl, Br or I;

[0071] Ri is independently -CXaFF -C(Xa)2H, or -C(Xa)3 in each formula, in which Xa is independently F, Cl, Br or I in each formula; and

[0072] R2 and R3 are each independently F, Cl, Br or I in each formula.

[0073] (5) The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to above (1), (2), (3) or (4): in above formula II- 1, II-2, II-3, or II-4, X2 is independently N or -CRx in each formula, in which Rxis H or F;

[0074] Ri is independently -C(Xa)2H or -C(Xa)3 in each formula, in which Xais F or Cl; and

[0075] R2 and R3 are each independently F or Cl in each formula.

[0076] In embodiments of the present invention, in above formula II- 1, II-2, II-3, or II-4, R2 and R3 may be the same as or different from each other.

[0077] In embodiments of the present invention, in above formula I, II, or I- 1, R2 and R3 may be the same as or different from each other, and specifically, R2 and R3 may be different from each other. For example, if one of R2 and R3 is F, the other may be Cl.

[0078] In embodiments of the present invention, in above formula I, II, II-2, II-3, or II-4, R2 and R3 may be the same as or different from each other, and specifically, R2 and R3 may be the same as each other. For example, both R2 and R3 may be F, or may be Cl.

[0079] (6) The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to above (1), (2), (3), (4) or (5): wherein the compound represented by formula I of the present invention may be any one selected from compounds 1 to 8 shown in table 1 below.

[0080] [Table 11

[0081]

[0082] (7) The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to above (1), (2), (3), (4), (5) or (6): wherein the compound represented by formula I of the present invention may be compound 1 or 5 shown in above table 1.

[0083] In the present invention, the term “pharmaceutically acceptable” may refer to the one which is physiologically acceptable and does not conventionally cause an allergic response such as gastrointestinal disturbance and dizziness, or other responses similar thereto, when administered into an individual.

[0084] The pharmaceutically acceptable salt of the present invention may be prepared by a conventional method known to those skilled in the art.

[0085] In the present invention, pharmaceutically acceptable salts may refer to the salts conventionally used in a pharmaceutical industry, for example, inorganic ion salts prepared from calcium, potassium, sodium, magnesium or the like; inorganic acid salts prepared from hydrochloric acid, nitric acid, phosphoric acid, bromic acid, iodic acid, perchloric acid, sulfuric acid, or the like; organic acid salts prepared 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, ascorbric acid, carbonic acid, vanillic acid, hydroiodic acid, etc.; sulfonic acid salts prepared from methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, or the like; amino acid salts prepared from glycine, arginine, lysine, etc.; amine salts prepared from trimethylamine, triethylamine, ammonia, pyridine, picoline, etc.; and the like, but types of salts meant in the present invention are not limited to those listed salts.

[0086] In the present invention, preferable salts may include hydrochloric acid, trifluoroacetic acid, citric acid, bromic acid, maleic acid, phosphoric acid, sulfuric acid, tartaric acid, etc.

[0087] A compound represented by formula I, II, II- 1, II-2, II-3, or II-4 of the present invention may include at least one asymmetric carbon, and thus may be present as a racemate, racemic mixture, single enantiomer (optical isomer), mixture of diastereomers and respective diastereomers thereof.

[0088] Such isomers may be separable by conventional techniques, for example, the compound represented by formula I, II, II- 1, II-2, II-3, or II-4 may be separable by column chromatography, division of HPLC, or the like. Alternatively, each stereoisomer of the compound represented by formula I, II, II- 1, II-2, II-3, or II-4 may be stereospecifically synthesized with a known arrangement of optically pure starting materials and / or reagents.

[0089] In the present invention, “stereoisomer” may include a diastereomer and an optical isomer (enantiomer), in which the optical isomer may include not only an enantiomer, but also a mixture of the enantiomer and even a racemate.

[0090] The compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 listed in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may show a histone deacetylase 6 (HDAC6) inhibitory activity, specifically a selective inhibitory activity against HDAC6, and more specifically a very high selective inhibitory activity against HDAC6 compared to other HDAC isotypes, and have a very high inhibitory activity against HDAC6, but little or no inhibitory activity against other HDAC isotypes (tables 3, 4 and 5).

[0091] The compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may remarkably increase acetylation of tubulin in nerve cells (FIGS. 4 and 5).

[0092] The compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may show an activity of preventing or treating histone deacetylase 6 (HDAC6) activity-related or -medicated diseases.

[0093] In the present invention, “prevention” may refer to all the acts, which inhibit or delay the occurrence of a disease by administering the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention.

[0094] In the present invention, “treatment” may refer to all the acts, by which a suspicious symptom of an individual likely to develop a disease or a symptom of an individual suffering from a disease gets better or takes a favorable turn by administering the compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention.

[0095] In the present specification, "histone deacetylase-mediated disease" may refer to a disease associated with histone deacetylase 6 (HDAC6) activity. In embodiments of the present invention, the histone deacetylase 6 (HDAC6) activity- related diseases or histone deacetylase 6-mediated diseases may include infectious diseases, neoplasm, endocrinopathy, nutritional and metabolic diseases, mental and behavioral disorders, neurological diseases, eye and ocular adnexal diseases, circulatory diseases, respiratory diseases, digestive troubles, skin and subcutaneous tissue diseases, musculoskeletal system and connective tissue diseases, or teratosis, deformities, and chromosomal aberration, etc.

[0096] In embodiments of the present invention, the infectious diseases may be prion disease; the neoplasm may be benign tumor or malignant tumor; the endocrinopathy, nutritional and metabolic diseases may be Wilson's disease, amyloidosis or diabetes; the mental and behavioral disorders may be depression or rett syndrome; the neurological diseases may be nervous system atrophy including central nervous system atrophy, neurodegenerative disease, motor disorder, neuropathy, motor neuron disease or central nervous system demyelinating disease; the eye and ocular adnexal diseases may be uveitis; the circulatory diseases may be atrial fibrillation or stroke; the respiratory diseases may be asthma; the digestive troubles may be alcoholic liver disease, inflammatory bowel disease, Crohn's disease or ulcerative bowel disease; the skin and subcutaneous tissue diseases may be psoriasis; the musculoskeletal system and connective tissue diseases may be rheumatoid arthritis, osteoarthritis or systemic lupus erythematosis; and the teratosis, deformities and chromosomal aberration may be autosomal dominant polycystic kidney disease.

[0097] In embodiments of the present invention, the nervous system atrophy including the central nervous system atrophy may be Huntington's disease, spinal muscular atrophy (SMA), or spinocerebellar ataxia (SCA); the neurodegenerative disease may be Alzheimer's disease or tauopathy; the motor disorder may be Parkinson's disease; the neuropathy disease may be hereditary neuropathy including Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie-Tooth disease) or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, or drug-induced neuropathy; the motor neuropathy may be amyotrophic lateral sclerosis (ALS); and the central nervous system demyelinating disease may be multiple sclerosis (MS).

[0098] In embodiments of the present invention, the histone deacetylase 6 (HDAC6) activity- related diseases or histone deacetylase 6-mediated diseases may include cancer, inflammatory diseases, autoimmune diseases, neurological or degenerative neurological diseases, specifically, lung cancer, colon cancer, breast cancer, prostate cancer, liver cancer, brain cancer, ovarian cancer, gastric cancer, skin cancer, pancreatic cancer, glioma, glioblastoma carcinoma, leukemia, lymphoma, multiple myeloma, solid cancer, Wilson's disease, spinocerebellar ataxia, prion disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, hereditary neuropathy including Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie-Tooth disease) or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, or drug-induced neuropathy, amyloidosis, Alzheimer's disease, alcoholic liver disease, spinal muscular atrophy, rheumatoid arthritis or osteoarthritis, in addition to symptoms or diseases related to abnormal functions of histone deacetylase 6.

[0099] The compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may show a high brain-vascular barrier permeability. Specifically, the compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may show a high B / P ratio upon oral administration (Table 10).

[0100] The compound represented by formula I, II, II- 1, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may show an excellent preventive and therapeutic effect on nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, hereditary neuropathy, or the like.

[0101] In embodiments of the present invention, the nervous system atrophy including the central nervous system atrophy, neurodegenerative diseases, or hereditary neuropathy may be Huntington's disease, spinal muscular atrophy (SMA), spinocerebellar ataxia (SCA), Alzheimer's disease, tauopathy, hereditary neuropathy including Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie- Tooth disease), hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, drug-induced neuropathy, amyotrophic lateral sclerosis (ALS), or multiple sclerosis (MS).

[0102] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers isomers thereof, or pharmaceutically acceptable salts thereof may show a remarkably excellent preventive and therapeutic effect on nervous system atrophy including central nervous system atrophy selected from the group consisting of Huntington's disease, dementia, Alzheimer's disease, amyloidosis, Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie-Tooth disease) and tauopathy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy.

[0103] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers isomers thereof, or pharmaceutically acceptable salts thereof may increase a relative velocity of mitochondrial axons, which is reduced by treatment with amyloid P protein fragment (AP), and this pharmacological effect may last for a long period of time. Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including dementia and Alzheimer’s disease, neurodegenerative diseases, or hereditary neuropathy (Tables 6, 7, 8, FIGS. 1 and 2).

[0104] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers isomers thereof, or pharmaceutically acceptable salts thereof may increase a relative velocity of mitochondrial axons reduced in nerve cells in which tau protein is overexpressed. Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including tauopathy, neurodegenerative diseases, or hereditary neuropathy (Table 9 and FIG. 3).

[0105] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably ameliorate a cognitive decline in tauopathic mice (PS 19 mice). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including tauopathy, neurodegenerative diseases, or hereditary neuropathy (FIGS. 6, 7 and 8).

[0106] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably reduce the hyperphosphorylation of tau observed in the brain of tauopathic mice (PS 19 mice). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including tauopathy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy (FIGS. 9, 10, 11, 12 and 13).

[0107] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers isomers thereof, or pharmaceutically acceptable salts thereof may remarkably enhance a long-term memory of the hippocampus lowered in tauopathic mice (PS 19 mice). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including tauopathy, neurodegenerative diseases, or hereditary neuropathy (FIGS. 14 and 15).

[0108] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably ameliorate the symptoms of ataxia in Huntington's disease model mice (Yacl28 mice) and may remarkably increase a grip force reduced in Huntington's disease model mice (Yacl28 mice). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Huntington's disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 16, 17, 18 and 19).

[0109] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably increase a relative velocity of mitochondria in dosal root ganglia (DRG) of Charcot-Marie-Tooth disease (CMT) model mice (MFN2 mutant mice). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (Table 11 and FIG. 20).

[0110] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably improve a falling delay time reduced in the CX32 null mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a constant velocity rotarod test), and may remarkably reduce a slip count and a transverse time of a rod which were increased in the CX32 null mouse model of Charcot-Marie-Tooth disease

[0111] (CMT) (as confirmed by a balance beam test). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 21 and 22).

[0112] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably improve a falling delay time reduced in the MFN2 mutant mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by an accelerating rotarod test), and may remarkably reduce a slip count which was increased in the MFN2 mutant mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a balance beam test). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 23 and 24).

[0113] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably improve a falling delay time reduced in the CMT2A mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by an accelerating rotarod test), and may remarkably reduce a slip count which was increased in the CMT2A mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a balance beam test). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 25 and 26).

[0114] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably improve a falling delay time reduced in the CMT1X mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by an constant rotarod test), and may remarkably reduce a slip count which was increased in the CMT1X mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a balance beam test). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 27 and 28).

[0115] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably improve a falling delay time reduced in the CMT1A mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by an constant rotarod test), and may remarkably reduce a slip count which was increased in the CMT1A mouse model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a balance beam test). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 29 and 30).

[0116] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably improve a sensory neuron action potential (SNAP) amplitude and a sensory neuron conduction velocity (SNCV), which were reduced in the MFN2 mutant mouse model of Charcot-Marie-Tooth disease (CMT). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIG. 31).

[0117] In embodiments of the present invention, the compound represented by formula I, II, II-l, II-2, II-3, or II-4, compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may remarkably increase an axon size of the sciatic nerve fibers, which was reduced in the CX32 null mouse model of Charcot-Marie-Tooth disease (CMT). Accordingly, the compounds of the present invention may exhibit excellent preventive and therapeutic effects on neuronal system atrophy such as central nervous system atrophy including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIG. 32).

[0118] Method for preparing compound

[0119] The present invention may provide a method for preparing an oxadiazole derivative compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0120] Hereinafter, in the reaction formulas, the same symbols as those of the formula I and not specifically described are the same as those defined in the formula I, and the overlapping description is omitted. In addition, in the reaction formulas, PG may represent an amine protecting group, and may be, for example, tert-Butyloxycarbonyl (Boc).

[0121] A preferable method for preparing an oxadiazole derivative compound represented by above formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof may be the same as shown in reaction formulas 1-1, 1-2 to 1-3 below, and even a preparation method modified at a level apparent to those skilled in the art may be also included therein.

[0122] In embodiments of the present invention, the preferable method for preparing the oxadiazole derivative compound represented by above formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof may be performed by a preparation method of reaction formula 1-1 below.

[0123] [Reaction Formula 1-1]

[0124]

[0125] In above [Reaction Formula 1-1], Xi to X4, Ri, R2, and R3 may be the same as those defined in formula I, PG may be a protecting group, halo may be F, Cl, Br, or I, and alkyl may be Ci to C5 alkyl.

[0126] In embodiments of the present invention, in above [Reaction Formula 1-1], Xi, X3 and X4 may be CH, X2 may be N, R2 and R3 may be each independently F or Cl, Ri may be CF2H, PG may be tert-butyl carboxylate, and alkyl may be methyl, ethyl or butyl.

[0127] In above [Reaction Formula 1-1], a compound represented by above 1-1-1, 1-1-2, 1- 1-3, 1-1-4, 1-1-5, 1-1-6, 1-1-7, 1-1-8, 1-1-9 or 1-1-10 may be each independently in the form of a salt, and the salt may be hydrochloride or trifluoroacetate.

[0128] Above [Reaction Formula 1-1] may show a method for synthesizing a 1,3,4-oxadiazole derivative compound, in which the compound of formula 1-1-1 including isocyanate may be reacted with the compound of formula 1-1-2 having a protecting group introduced thereinto, so as to prepare the compound of formula 1-1-3 including an urea structure.

[0129] After that, the resulting compound may be subjected to a substitution reaction with the compound of formula 1-1-4 to prepare the compound of formula 1-1-5, and then a protecting group may be removed to prepare the compound of formula 1-1-6.

[0130] The compound of formula 1-1-6 may be subjected to a reductive amination reaction with the compound of formula 1-1-7 to prepare the compound of formula 1-1-8, and then reacted with hydrazine to prepare the compound of formula 1-1-9 which is a hydrazide compound. After that, difluoroacetic anhydride and imidazole may be used to prepare the compound of formula 1-1-10.

[0131] In embodiments of the present invention, in reaction formula [Reaction Formula 1-1], the compound of above formula 1-1-10 may be compound 3.

[0132] In embodiments of the present invention, the preferable method for preparing the oxadiazole derivative compound represented by above formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof may be performed by a preparation method of reaction formula 1-2 below.

[0133] [Reaction Formula 1-2]

[0134] In above [Reaction Formula 1-2], Xi to X4, Ri, R2, and R3 may be the same as those defined in formula I, PG may be a protecting group, halo may be F, Cl, Br, or I, and alkyl may be Ci to C5 alkyl.

[0135] In embodiments of the present invention, in above [Reaction Formula 1-2], Xi, X3 and X4 may be CH, X2 may be N or -CRx (Rx may be F or Cl, Br or I), R2 and R3 may be each independently F or Cl, Ri may be CF2H, PG may be tert-butyl carboxylate, and alkyl may be methyl, ethyl or butyl.

[0136] In above [Reaction Formula 1-2], a compound represented by above 1-1-1, 1-2-1, 1- 2-2, 1-1-4, 1-1-8, 1-1-9 or 1-1-10 may be each independently in the form of a salt, and the salt may be hydrochloride or trifluoroacetate.

[0137] Above [Reaction Formula 1-2] may show a method for synthesizing a 1,3,4-oxadiazole compound having an oxetane structure, in which the compound of formula 1-1-1 including isocyanate may be reacted with the compound of formula 1-2-1 having an oxetane introduced thereinto, so as to prepare the compound of formula 1-2-2 including an urea structure.

[0138] The compound of formula 1-2-2 may be subjected to a substitution reaction with the compound of formula 1-1-4 to prepare the compound 1-1-8, and then reacted with hydrazine to prepare the compound of formula 1-1-9 which is a hydrazide compound. After that, difluoroacetic anhydride and imidazole may be used to prepare the target compound of formula 1-1-10.

[0139] In embodiments of the present invention, in above [Reaction Formula 1-2], the compound of above formula 1-1-10 may be compound 4, compound 5, compound 6, compound 7, compound 8, or the like.

[0140] In embodiments of the present invention, the preferable method for preparing the oxadiazole derivative compound represented by above formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof may be performed by a preparation method of reaction formula 1-3 below.

[0141] [Reaction Formula 1-3]

[0142]

[0143] In above [Reaction Formula 1-3], Xi to X4, Ri, R2, and R3 may be the same as those defined in formula I, PG may be a protecting group, halo may be F, Cl, Br, or I, and alkyl may be Ci to C5 alkyl.

[0144] In embodiments of the present invention, in above [Reaction Formula 1-3], Xi, X3 and X4 may be CH, X2 may be CH or -CRx (Rx may be F or Cl, Br or I), R2 and R3 may be each independently F or Cl, Ri may be CF2H, PG may be tert-butyl carboxylate, and alkyl may be methyl, ethyl or butyl.

[0145] In above [Reaction Formula 1-3], a compound represented by above 1-3-1, 1-1-2, 1- 1-4, 1-3-2, 1-1-5, 1-1-6, 1-1-7, 1-1-8, 1-1-9 or 1-1-10 may be each independently in the form of a salt, and the salt may be hydrochloride or trifluoroacetate.

[0146] Above [Reaction Formula 1-3] may show a method for synthesizing an oxadiazole compound having an oxetane structure, in which the compound of formula 1-3-1 including an amine group may be subjected to a substitution reaction with the compound of formula 1-1-4 to prepare the compound of formula 1-3-2, and then may be reacted with the compound of formula 1-1-2 having a protecting group introduced thereinto, so as to prepare the compound of formula 1-1-5 including an urea structure. After that, the protecting group of formula 1-1-5 may be removed to prepare the compound of formula 1-1-6.

[0147] The compound of formula 1-1-6 may be subjected to a reductive amination reaction with the compound of formula 1-1-7 to prepare the compound of formula 1-1-8, and then reacted with hydrazine to prepare the compound of formula 1-1-9 which is a hydrazide compound. After that, difluoroacetic anhydride and imidazole may be used to prepare the target compound of formula 1-1-10.

[0148] In embodiments of the present invention, in above [Reaction Formula 1-3], the compound of above formula 1-1-10 may be compound 1, compound 2, or the like.

[0149] Pharmaceutical composition., treatment method using the same, and use thereof

[0150] The present invention may provide a pharmaceutical composition including a compound represented by above formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0151] According to embodiments of the present invention, the compound represented by formula I included in the pharmaceutical composition may be a compound represented by above formula II.

[0152] According to embodiments of the present invention, the compound represented by formula I included in the pharmaceutical composition may be a compound represented by above formula II- 1 , II-2, II-3, or II-4.

[0153] The present invention may provide a pharmaceutical composition including a compound of at least one of compounds 1 to 8 described in above table 1, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0154] The present invention may provide a pharmaceutical composition including a compound of at least one of compounds 1 and 5 described in above table 1, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0155] The present invention may provide a pharmaceutical composition for preventing or treating histone deacetylase-mediated diseases including a compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, a compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof as an effective ingredient.

[0156] The present invention may provide a pharmaceutical composition for preventing or treating histone deacetylase 6-mediated diseases including a compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, a compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof as an effective ingredient.

[0157] The pharmaceutical composition of the present invention may exhibit the same kind of pharmacological effect as the pharmacological effect exhibited by a compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, a compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof.

[0158] In the pharmaceutical composition, the histone deacetylase 6-mediated diseases may be substantially the same as the histone deacetylase 6-mediated diseases previously examined in the compound.

[0159] In embodiments of the present invention, the histone deacetylase 6 (HDAC6) activity- related diseases or -mediated diseases may include infectious diseases, neoplasm, endocrinopathy, nutritional and metabolic diseases, mental and behavioral disorders, neurological diseases, eye and ocular adnexal diseases, circulatory diseases, respiratory diseases, digestive troubles, skin and subcutaneous tissue diseases, musculoskeletal system and connective tissue diseases, or teratosis, deformities, and chromosomal aberration, etc.

[0160] In embodiments of the present invention, the infectious diseases may be prion disease; the neoplasm may be benign tumor or malignant tumor; the endocrinopathy, nutritional and metabolic diseases may be Wilson's disease, amyloidosis or diabetes; the mental and behavioral disorders may be depression or rett syndrome; the neurological diseases may be nervous system atrophy including central nervous system atrophy, neurodegenerative disease, motor disorder, neuropathy, motor neuron disease or central nervous system demyelinating disease; the eye and ocular adnexal diseases may be uveitis; the circulatory diseases may be atrial fibrillation or stroke; the respiratory diseases may be asthma; the digestive troubles may be alcoholic liver disease, inflammatory bowel disease, Crohn's disease or ulcerative bowel disease; the skin and subcutaneous tissue diseases may be psoriasis; the musculoskeletal system and connective tissue diseases may be rheumatoid arthritis, osteoarthritis or systemic lupus erythematosis; and the teratosis, deformities and chromosomal aberration may be autosomal dominant polycystic kidney disease.

[0161] In embodiments of the present invention, the nervous system atrophy including the central nervous system atrophy may be Huntington's disease, spinal muscular atrophy (SMA), or spinocerebellar ataxia (SCA); the neurodegenerative disease may be Alzheimer's disease or tauopathy; the motor disorder may be Parkinson's disease; the neuropathy disease may be hereditary neuropathy including Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie-Tooth disease) or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, or drug-induced neuropathy; the motor neuropathy may be amyotrophic lateral sclerosis (ALS); and the central nervous system demyelinating disease may be multiple sclerosis (MS). In embodiments of the present invention, the histone deacetylase 6 (HDAC6) activity- related diseases or -mediated diseases may include cancer, inflammatory diseases, autoimmune diseases, neurological or degenerative neurological diseases, specifically, lung cancer, colon cancer, breast cancer, prostate cancer, liver cancer, brain cancer, ovarian cancer, gastric cancer, skin cancer, pancreatic cancer, glioma, glioblastoma carcinoma, leukemia, lymphoma, multiple myeloma, solid cancer, Wilson's disease, spinocerebellar ataxia, prion disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, hereditary neuropathy including Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie-Tooth disease) or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, or drug-induced neuropathy, amyloidosis, Alzheimer's disease, alcoholic liver disease, spinal muscular atrophy, rheumatoid arthritis or osteoarthritis, in addition to symptoms or diseases related to abnormal functions of histone deacetylase 6.

[0162] The present invention may provide a pharmaceutical composition for preventing or treating nervous system atrophy including central nervous system atrophy, etc., neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy including a compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, a compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof as an effective ingredient.

[0163] In the pharmaceutical composition, nervous system atrophy, neurodegenerative diseases and hereditary neuropathy may be substantially the same as the degenerative brain disease previously examined in the compound.

[0164] In embodiments of the present invention, the degenerative brain diseases may be Huntington's disease, spinal muscular atrophy (SMA), spinocerebellar ataxia (SCA), Alzheimer's disease, tauopathy, hereditary neuropathy including Charcot-Marie-Tooth disease (peripheral neuropathic Charcot-Marie-Tooth disease, central neuropathic Charcot-Marie- Tooth disease) or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, drug-induced neuropathy, amyotrophic lateral sclerosis (ALS), or multiple sclerosis (MS), and specifically Huntington's disease, dementia, Alzheimer's disease, amyloidosis, or tauopathy.

[0165] In the pharmaceutical composition, the stereoisomer and the pharmaceutically acceptable salt may be the same as described in the stereoisomer and the pharmaceutically acceptable salt described above in the compound.

[0166] The pharmaceutical composition of the present invention may further include at least one of a pharmaceutically acceptable additive, in addition to the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof.

[0167] In embodiments of the present invention, the pharmaceutically acceptable additives used may include saline solution, sterilized water, Ringer's solution, buffered saline, dextrose solution, maltodextrin solution, glycerol, ethanol and a mixture of one or more ingredients thereof, and may include the addition of other conventional additives such as antioxidant, buffer solution, bacteriostatic agent, etc., if needed. In addition, diluent, dispersing agent, surfactant, binder and lubricant may be further added to be formulated into injectable formulations such as aqueous solution, suspension, emulsion, etc., pill, capsule, granule or tablet. Thus, the composition of the present invention may be patch, liquid medicine, pill, capsule, granule, tablet, suppository, etc. The preparations may be prepared according to a conventional method used for formulation in the art or a method disclosed in Remington's Pharmaceutical Science (latest edition), Mack Publishing Company, Easton PA, and the composition may be formulated into various preparations depending on each disease or ingredient. In embodiments of the present invention, pharmaceutically acceptable additives which may be included in the pharmaceutical compositions may be those conventionally used in the art, specifically including, but not limited thereto, lactose, dextrose, sucrose, sorbitol, mannitol, glycine, starch, tragacanth rubber, acacia rubber, calcium phosphate, calcium chloride, sodium chloride, alginic acid, sodium alginate, gelatin, calcium silicate, microcrystalline cellulose, polyvinyl pyrrolidine, polyethylene glycol, cellulose, water, ethanol, syrup, methyl cellulose, methyl hydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate, magnesium aluminum silicate, silica, orange essence, strawberry essence, vanilla essence, or mineral oil.

[0168] The pharmaceutical composition of the present invention may be orally or parenterally administered (for example, applied intravenously, hypodermically, intraperitoneally or locally) according to an intended method, in which a dosage thereof may vary in a range thereof depending on factors including a patient’s weight, age, gender, health condition, diet, an administration time, an administration method, an administration route, an excretion rate, a type of disease, a severity of disease, a treatment period, a drug combined or concurrently used, as well as other factors well known in a medical field, and may be determined by those skilled in the art considering all the above factors.

[0169] A daily dosage of the pharmaceutical composition including the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof according to the present invention may be about 1 to 1000 mg / kg, preferably about 5 to 100 mg / kg, and may be administered at one time a day or several times a day by dividing the daily dosage of the composition.

[0170] The pharmaceutical composition of the present invention may further include at least one effective ingredient which shows the same or similar medicinal effects, in addition to the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof.

[0171] The present invention may provide a method for preventing or treating HDAC6 activity-related diseases or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy, including administering to an individual the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof, or the pharmaceutical composition including the same.

[0172] The method for preventing or treating histone deacetylase 6 activity-related diseases or degenerative brain diseases of the present invention may include not only dealing with the diseases per se before expression of symptoms, but also inhibiting or avoiding such symptoms by administering the compound represented by above formula I, II, II-l, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof. In managing the diseases, a preventive or therapeutic dose of a certain active ingredient may vary depending on a nature and severity of the diseases or conditions, and a route of administering the active ingredient. A dose and a frequency thereof may vary depending on an individual patient’s age, weight and reactions. A suitable dose and usage may be easily selected by those skilled in the art, naturally considering such factors.

[0173] In the method of the present invention, histone deacetylase 6 activity-related diseases or degenerative brain diseases may be the same as described above.

[0174] In the present invention, “administration” may refer to introducing a predetermined substance into an individual by an appropriate method.

[0175] In the present invention, “individual” may refer to all the animals such as rats, mice, livestock, etc., including humans, who are likely to develop or have already developed HDAC6 activity-related diseases or degenerative brain diseases, and specifically may refer to mammals including humans, but is not limited thereto.

[0176] The method for preventing or treating HDAC6 activity-related diseases of the present invention or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy may refer to administering a therapeutically effective amount of the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof.

[0177] In the present invention, “therapeutically effective amount” may refer to an amount enough to treat a disease at a reasonable risk / benefit ratio applicable to medical treatment and not to cause a side effect, and may refer to an amount of the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof, which is effective in preventing or treating histone deacetylase 6 activity-related diseases or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy.

[0178] In addition, the method for preventing or treating histone deacetylase 6 activity-related diseases of the present invention or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy may further include administering a therapeutically effective amount of an additional active agent, which is helpful in treating the diseases, along with the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof, and an additional active agent may show a synergy effect, an additive effect or an adjuvant effect together with the compound represented by above formula I, II, II-l, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof.

[0179] The present invention may provide a use of the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof, or the pharmaceutical composition including the same for preventing or treating HDAC6 activity- related diseases or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy.

[0180] The present invention may provide a use of the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof, or the pharmaceutical composition including the same for preparing a medicament for preventing or treating HDAC6 activity-related diseases or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy.

[0181] In the use of the present invention, histone deacetylase 6 activity-related diseases or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy may be the same as described above.

[0182] For preparation of the medicament, the compound represented by above formula I, II, II- 1, II-2, II-3, or II-4 of the present invention, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof, or pharmaceutically acceptable salts thereof may be mixed with pharmaceutically acceptable adjuvants, diluents, carriers, etc., and may be prepared into a complex preparation together with other active agents, thus providing a synergy action.

[0183] Matters mentioned in each of the items of the present invention, that is, the oxadiazole derivative compound, the preparation method thereof, the pharmaceutical composition including the same, the treatment method using the same, and the use thereof may be applied the same, if not contradictory to each other.

[0184] Advantageous Effects

[0185] A novel oxadiazole derivative compound, stereoisomers thereof or pharmaceutically acceptable salts thereof according to the present invention can have a selective HDAC6 inhibitory activity, and show excellent preventive or therapeutic effects on HDAC6 activity- related diseases or nervous system atrophy including central nervous system atrophy, neurodegenerative diseases including degenerative brain diseases, or hereditary neuropathy.

[0186] Brief Description of Drawings

[0187] FIGS. 1 and 2 show results of evaluating an effect of the compound of the present invention on a relative velocity of mitochondrial axons, which is reduced by treatment with Ap in mouse hippocampal neurons.

[0188] FIG. 3 shows results of evaluating an effect of the compound of the present invention on a relative velocity of mitochondrial axons, which is reduced in mouse primary cultured cells in which human tau protein having a P301L mutation is overexpressed.

[0189] FIGS. 4 and 5 show results of evaluating an effect of the compound of the present invention on acetylation of tubulin in SH-SY5Y cells, a human neuroblastoma.

[0190] FIGS. 6 to 8 show results of evaluating an effect of the compound of the present invention on cognitive decline due to tauopathy in PS 19 mice. FIGS. 9 to 13 show results of evaluating an effect of the compound of the present invention on hyperphosphorylation of tau in brain of PS 19 mice.

[0191] FIGS. 14 and 15 show results of evaluating an effect of the compound of the present invention on enhanced long-term memory of hippocampus lowered in PS 19 mice.

[0192] FIGS. 16 to 19 show results of evaluating an effect of the compound of the present invention on motor function lowered in Yacl28 mice.

[0193] FIG. 20 shows results of evaluating an effect of the compound of the present invention on a relative velocity of mitochondrial axons, which is reduced in an animal model of Charcot- Marie-Tooth disease (MFN2 mutant mice).

[0194] FIGS. 21 and 22 show results of evaluating an effect of the compound of the present invention on motor and sensory functions (rotarod, balance beam test), which are reduced in an animal model of Charcot-Marie-Tooth disease (CX32 null mice).

[0195] FIGS. 23 and 24 show results of evaluating an effect of the compound of the present invention on motor and sensory functions (rotarod, balance beam test), which are reduced in an animal model of Charcot-Marie-Tooth disease (MFN2 mutant mice).

[0196] FIGS. 25 and 26 show results of evaluating an effect of the compound of the present invention on motor and sensory functions (rotarod, balance beam test), which are reduced in an animal model of Charcot-Marie-Tooth disease (CMT2A mice).

[0197] FIGS. 27 and 28 show results of evaluating an effect of the compound of the present invention on motor and sensory functions (rotarod, balance beam test), which are reduced in an animal model of Charcot-Marie-Tooth disease (CMT1X mice).

[0198] FIGS. 29 and 30 show results of evaluating an effect of the compound of the present invention on motor and sensory functions (rotarod, balance beam test), which are reduced in an animal model of Charcot-Marie-Tooth disease (CMTIA mice).

[0199] FIG. 31 shows results of evaluating an effect of the compound of the present invention on a nerve conduction velocity, which is reduced in an animal model of Charcot-Marie-Tooth disease (MFN2 mutant mice).

[0200] FIG. 32 shows results of evaluating an effect of the compound of the present invention on an axon size of the sciatic nerve fibers, which is reduced in an animal model of Charcot- Marie-Tooth disease (CX32 null mice).

[0201] Mode for Invention

[0202] Hereinafter, the present invention will be described in more detail through exemplary embodiments. These exemplary embodiments are provided only for the purpose of illustrating the present invention, and thus it will be apparent to those skilled in the art that the scope of the present invention is not limited thereto.

[0203] Preparation of compound

[0204] A specific method for preparing the compound represented by formula I is the same as follows.

[0205] Example 1: Synthesis of compound 1 (compound 1), A-(3-chloro-4-fluorophenyl)-

[0206] 7V-(4-(5-(difluoromethyl)-l,3,4-oxadiazol-2-yl)benzyl)-4-(oxetan-3-yl)piperazin-l- carboxamide

[0207] [Step 1] Synthesis of methyl 4-(((3-chloro-4-fluorophenyl)amino)methyl)benzoate

[0208] A solution of 3-chloro-4-fluoroaniline (2.911 g, 20.000 mmol) and sodium hydride (60.00%, 0.880 g, 22.000 mmol) dissolved in A A-dimethylformamide (80 mL) was stirred at room temperature for 30 minutes, after which methyl 4-(bromomethyl)benzoate (4.581 g, 20.000 mmol) was added thereto and further stirred at the same temperature for 18 hours. Water was poured into the reaction mixture and extracted with ethyl acetate. An organic layer was washed with a saturated aqueous sodium chloride solution, dehydrated with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCb, 40 g cartridge; ethyl acetate / hexane = 0 to 10%) and concentrated to obtain a title compound (3.711 g, 63.2%) as a brown oil form.

[0209] [Step 2] Synthesis of tert-butyl 4-((3-chloro-4-fluorophenyl)(4-

[0210] (methoxy carbonyl)benzyl)carbamoyl)piperazin-l -carboxylate

[0211] A solution of methyl 4-(((3-chloro-4-fluorophenyl)amino)methyl)benzoate (3.711 g, 12.635 mmol) prepared in step 1, M-V-diisopropylethylamine (4.401 mL, 25.270 mmol) and triphosgene (1.875 g, 6.317 mmol) dissolved in dichloromethane (50 mL) was stirred at room temperature for 10 minutes, after which tert-butyl piperazin- 1 -carboxylate (2.353 g, 12.635 mmol) was added thereinto and further stirred at room temperature for 18 hours. Solvent was removed from the reaction mixture under reduced pressure, and then a title compound was used without an additional purification process (6.300 g, 98.5 %, brown oil).

[0212] [Step 3] Synthesis of methyl 4-((A-(3-chloro-4-fluorophenyl)piperazin-l- carb oxami do)methy l)b enzoate hydrochi ori de A solution of tert-butyl 4-((3-chloro-4-fluorophenyl)(4- (methoxycarbonyl)benzyl)carbamoyl)piperazin-l -carboxylate (6.300 g, 12.451 mmol) prepared in step 2 and hydrogen chloride (4.00 M solution in 1,4-dioxane, 12.451 mL, 49.805 mmol) dissolved in dichloromethane (50 mL) at room temperature was stirred at the same temperature for three hours. A precipitated solid was filtered, washed with dichloromethane, and dried to obtain a title compound (3.647 g, 66.2%) in a white solid form.

[0213] [Step 4] Synthesis of methyl 4-((A-(3-chloro-4-fluorophenyl)-4-(oxetan-3- yl)piperazine-l-carboxamido)methyl)benzoate

[0214] A solution of methyl 4-((7V-(3-chloro-4-fluorophenyl)piperazin-l- carboxamido)methyl)benzoate hydrochloride (0.885 g, 2.000 mmol) prepared in step 3, oxetan-

[0215] 3-one (0.234 mL, 4.000 mmol) and sodium triacetoxyborohydride (0.848 g, 4.000 mmol) dissolved in dichloromethane (10 mL) at room temperature was stirred at the same temperature for 18 hours. Water was poured into the reaction mixture, extracted with di chloromethane, and filtered via a plastic filter to remove a solid residue and an aqueous solution layer therefrom, and then concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCb, 12 g cartridge; methanol / dichlorom ethane = 0 to 5%) and concentrated to obtain a title compound (0.626 g, 67.7%) as a brown oil form.

[0216] [Step 5] Synthesis of A-(3-chloro-4-fluorophenyl)-A-(4-(hydrazinecarbonyl)benzyl)-

[0217] 4-(oxetan-3-yl)piperazine-l -carboxamide

[0218] A solution of methyl 4-((7V-(3-chloro-4-fluorophenyl)-4-(oxetan-3-yl)piperazin-l- carboxamido)methyl)benzoate (0.626 g, 1.355 mmol) prepared in step 4 and hydrazine monohydrate (1.317 mL, 27.104 mmol) dissolved in ethanol (6 mL) at room temperature was stirred at 75°C for 18 hours, after which a reaction was finished by lowering the temperature to room temperature. Solvent was removed from the resulting mixture under reduced pressure, and then the resulting concentrate was purified via column chromatography (SiCb, 12 g cartridge; methanol / di chloromethane = 0 to 10%) and concentrated to obtain a title compound (0.435 g, 69.5%) in a white solid form.

[0219] [Step 6] Synthesis of compound 1

[0220] A solution of 7V-(3-chloro-4-fluorophenyl)-A-(4-(hydrazinecarbonyl)benzyl)-4- (oxetan-3-yl)piperazin-l -carboxamide (0.100 g, 0.216 mmol) prepared in step 5, triethylamine (0.091 mL, 0.649 mmol) and 2,2-difluoroacetic anhydride (0.081 mL, 0.649 mmol) dissolved in di chloromethane (2 mL) at room temperature was stirred at 40°C for 18 hours, after which a reaction was finished by lowering the temperature to room temperature. Water was poured into the reaction mixture, extracted with dichloromethane, filtered via a plastic filter to remove a solid residue and an aqueous solution layer therefrom, and concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCb, 4 g cartridge; ethyl acetate / hexane = 0 to 60%) and concentrated to obtain compound 1 (0.099 g, 87.9%) in a white solid form.

[0221] 'H NMR (400 MHz, CDCh) 6 8.07 - 8.04 (m, 2H), 7.46 (d, 2H, J= 8.5 Hz), 7.15 (dd, 1H, J= 6.3, 2.7 Hz), 7.10 (t, 1H, J= 8.6 Hz), 7.05 - 6.80 (m, 2H), 4.90 (s, 2H), 4.77 - 4.74 (m, 2H), 4.68 (t, 2H, J= 6.9 Hz), 3.68 - 3.65 (m, 1H), 3.49 - 3.47 (m, 4H), 2.43 (brs, 4H); LRMS (ES) m / z 522.4 (M++ 1).

[0222] Example 2: Synthesis of compound 2, 7V-(3-chloro-4-fluorophenyl)-7V-(4-(5- (difluoromethyl)-l,3,4-oxadiazol-2-yl)-2-fluorobenzyl)-4-(oxetan-3-yl)piperazin-l- carb oxami de

[0223] Compound 2 was prepared in accordance with the same reactions as described in steps 1 to 6 of example 1, except for using methyl 4-(bromomethyl)-3 -fluorobenzoate instead of methyl 4-(bromomethyl)benzoate in step 1 of example 1.

[0224] 'H NMR (400 MHz, CDCh) 6 7.89 (dd, 1H, J = 8.0, 1.6 Hz), 7.77 (dd, 1H, J = 10.1, 1.6 Hz), 7.68 (t, 1H, J = 7.6 Hz), 7.19 (dd, 1H, J = 6.3, 2.7 Hz), 7.12 (t, 1H, J = 8.6 Hz), 7.06 - 6.80 (m, 2H), 4.92 (s, 2H), 4.75 - 4.72 (m, 2H), 4.67 (t, 2H, J = 6.9 Hz), 3.68 - 3.61 (m, 1H), 3.47 - 3.45 (m, 4H), 2.41 (brs, 4H); LRMS (ES) m / z 540.4 (M++ 1).

[0225] Example 3: Synthesis of compound 3, 7V-(3-chloro-4-fluorophenyl)-7V-((5-(5-

[0226] (difluoromethyl)-l,3,4-oxadiazol-2-yl)pyridin-2-yl)methyl)-4-(oxetan-3-yl)piperazin-l- carboxamide

[0227] [Step 1] Synthesis of tert-butyl 4-((3-chloro-4-fluorophenyl)((5-

[0228] (methoxycarbonyl)pyridin-2-yl)methyl)carbamoyl)piperazin-l-carboxylate Methyl 6-(bromomethyl)nicotinate (1.013 g, 4.402 mmol) was added to a solution of tert-butyl 4-((3-chloro-4-fluorophenyl)carbamoyl)piperazin-l -carboxylate (1.500 g, 4.192 mmol) and sodium hydride (60.00%, 0.184 g, 4.611 mmol) dissolved in N,N- dimethylformamide (30 mL) at 0°C and was stirred at the same temperature for one hour. A saturated aqueous sodium hydrogen carbonate solution was poured into the reaction mixture, and extracted with ethyl acetate. An organic layer was washed with a saturated aqueous sodium chloride solution, dehydrated with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCh, 24 g cartridge; ethyl acetate / hexane = 20 to 60%), and concentrated to obtain a title compound (2.000 g, 94.1 %) in a yellow solid form.

[0229] [Step 2] Synthesis of methyl 6-((A-(3-chloro-4-fluorophenyl)piperazin-l- carb oxami do)methy 1 ) ni cotinate hydrochi ori de

[0230] A solution of tert-butyl 4-((3-chloro-4-fluorophenyl)((5-(methoxycarbonyl)pyridin-2- yl)methyl)carbamoyl)piperazin-l -carboxylate (2.000 g, 3.945 mmol) prepared in step 1 and hydrochloric acid (4.00 M solution in 1,4-dioxane, 4.931 mL, 19.725 mmol) dissolved in di chloromethane (50 mL) at room temperature was stirred at the same temperature for 18 hours. A saturated aqueous sodium hydrogen carbonate solution was poured into the reaction mixture, and extracted with dichloromethane. An organic layer was washed with saturated aqueous sodium chloride solution, dehydrated with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. Ethyl acetate was put into the resulting concentrate and stirred to filter a precipitated solid, which was then washed with ethyl acetate, and then dried to obtain a title compound (1.120 g, 64.0%) in a yellow solid form.

[0231] [Step 3] Synthesis of methyl 6-((7V-(3-chloro-4-fluorophenyl)-4-(oxetan-3- yl)piperazin- 1 -carboxamido)methyl)nicotinate

[0232] Oxetan-3-one (0.194 mL, 3.032 mmol) was added to a solution of methyl 6-((7V-(3- chloro-4-fluorophenyl)piperazin-l-carboxamido)methyl)nicotinate hydrochloride (1.120 g, 2.527 mmol) prepared in step 2 and 7V,7V-diisopropylethylamine (0.440 mL, 2.527 mmol) dissolved in dichloromethane (20 mL) at room temperature, and stirred at the same temperature. Sodium triacetoxyborohydride (0.803 g, 3.790 mmol) was added to the reaction mixture, and further stirred at the same temperature for 18 hours. A saturated aqueous sodium hydrogen carbonate solution was poured into the reaction mixture, extracted with di chloromethane, filtered via a plastic filter to remove a solid residue and an aqueous solution layer therefrom, and concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCb, 24 g cartridge; ethyl acetate = 100%), and concentrated to obtain a product, which was then purified again via chromatography (SiCh, 24 g cartridge; methanol / di chloromethane = 0 to 10%), and concentrated to obtain a title compound (0.467 g, 39.9 %) in a yellow oil form.

[0233] [Step 4] Synthesis of A-(3-chloro-4-fluorophenyl)-7V-((5-(hydrazinecarbonyl)pyridin-

[0234] 2-yl)methyl)-4-(oxetan-3-yl)piperazin-l -carboxamide

[0235] A solution of methyl 6-((7V-(3-chloro-4-fluorophenyl)-4-(oxetan-3-yl)piperazin-l- carboxamido)methyl)nicotinate (0.467 g, 1.009 mmol) prepared in step 3 and hydrazine monohydrate (0.981 mL, 20.177 mmol) dissolved in ethanol (4 mL) at room temperature was stirred at 110°C for 18 hours, after which a reaction was finished by lowering the temperature to room temperature. Solvent was removed from the reaction mixture under reduced pressure, and then a title compound was used without an additional purification process (0.460 g, 98.5%, yellow solid).

[0236] [Step 5] Synthesis of compound 3

[0237] 2,2-difluoroacetic anhydride (0.379 mL, 3.046 mmol) was added to a solution of N-(3- chl oro-4-fluorophenyl)-A-((5-(hydrazinecarbonyl)pyri din-2 -yl)methyl)-4-(oxetan-3- yl)piperazin-l -carboxamide (0.470 g, 1.015 mmol) prepared in the step 4 and imidazole (0.207 g, 3.046 mmol) dissolved in dichloromethane (10 mL) at room temperature, and reflux (under heated) for 18 hours, after which a reaction was finished by lowering the temperature to room temperature. A saturated aqueous sodium hydrogen carbonate solution was poured into the reaction mixture, extracted with dichloromethane, filtered via a plastic filter to remove a solid residue and an aqueous solution layer therefrom, and concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCb, 12 g cartridge; methanol / di chloromethane = 0 to 2.5%), and concentrated to obtain compound 3 (0.167 g, 31.5%) in a yellow solid form.

[0238] 'H VMR (400 MHz, CDCh) 6 9.25 (dd, J= 2.2, 0.7 Hz, 1H), 8.34 (dd, J= 20.0, 22.2 Hz, 1H), 7.60 (d, J= 8.2 Hz, 1H), 7.29 - 7.27 (m, 2H), 7.13 - 6.83 (m, 3H), 5.06 (s, 2H), 4.65 (t, J= 6.6 Hz, 2H), 4.56 (t, J = 6.0 Hz, 2H), 3.46 - 3.43 (m, 1H), 3.34 - 3.33 (m, 4H), 2.19 - 2.18 (m, 4H); LRMS (ES) m / z 523.3 (M++ 1).

[0239] Example 4: Synthesis of compound 4, A-(3,4-dichlorophenyl)-A-(4-(5-

[0240] (difluoromethyl)-l,3,4-oxadiazol-2-yl)-2-fluorobenzyl)-4-(oxetan-3-yl)piperazin-l- carb oxami de

[0241] [Step 1] Synthesis of tert-butyl 4-(oxetan-3-yl)piperazin-l -carboxylate

[0242] Sodium triacetoxyborohydride (11.379 g, 53.688 mmol) was added to a solution of tert-butyl piperazin- 1 -carboxylate (5.000 g, 26.844 mmol) and oxetan-3-one (2.902 g, 40.266 mmol) dissolved in dichloromethane (200 mL) at room temperature and was stirred at the same temperature for 18 hours. A saturated aqueous sodium hydrogen carbonate solution was poured into the reaction mixture and extracted with dichloromethane. An organic layer was washed with a saturated aqueous sodium chloride solution, dehydrated with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. Diethylether was added to the resulting concentrate and stirred to filter a precipitated solid, which was then washed with diethylether, and then dried to obtain a title compound (6.230 g, 95.8%) in a white solid form.

[0243] [Step 2] Synthesis of l-(oxetan-3-yl)piperazine trifluoroacetic acid salt A solution of tert-butyl 4-(oxetan-3-yl)piperazin-l -carboxylate (6.230 g, 25.710 mmol) prepared in step 1 and trifluoroacetic acid (5.906 mL, 77.129 mmol) dissolved in dichloromethane (50 mL) at room temperature was stirred at the same temperature for seven hours. Solvent was removed from the reaction mixture under reduced pressure, and then ethyl acetate was added to the resulting concentrate and stirred to filter out a precipitated solid, which was then washed with ethyl acetate and dried to obtain a title compound (4.720 g, 76.7%) in a white solid form.

[0244] [Step 3] Synthesis of 7V-(3 ,4-di chi orophenyl)-4-(oxetan-3-yl)piperazin-l -carboxamide

[0245] A solution of 3, 4-di chlorophenyl isocyanate (0.300 g, 1.596 mmol) prepared in step 2 and l-(oxetan-3-yl)piperazine 2,2,2-trifluoroacetate (0.409 g, 1.596 mmol) dissolved in diethyl ether (10 mL) at room temperature was stirred at the same temperature for two hours. The resulting precipitated solid was filtered, washed with diethyl ether, and dried to obtain a title compound (0.497 g, 94.3%) in a white solid form.

[0246] [Step 4] Synthesis of 7V-(3,4-di chi orophenyl)-4-(oxetan-3-yl)piperazin-l -carboxamide

[0247] Methyl 4-(bromomethyl)-3-fluorobenzoate (0.173 g, 0.700 mmol) was added to a solution of A-(3, 4-di chi orophenyl)-4-(oxetan-3-yl)piperazin-l -carboxamide (0.210 g, 0.636 mmol) prepared in step 3 and sodium hydride (60.00%, 0.028 g, 0.700 mmol) dissolved inN,N- dimethylformamide (4 mL) at 0°C and was stirred at room same temperature for 18 hours. Solvent was removed from the reaction mixture under reduced pressure, and then water was poured into the resulting concentrate, extracted with dichloromethane, filtered via a plastic filter to remove a solid residue and an aqueous solution layer therefrom, and concentrated under reduced pressure. The resulting concentrate was purified via column chromatography (SiCh, 4 g cartridge; methanol / dichloromethane = 0 to 5%), and concentrated to obtain a title compound (0.170 g, 53.8%) in a light yellow solid form.

[0248] [Step 5] Synthesis of A-(3,4-dichlorophenyl)-7V-(2-fluoro-4- (hydrazinecarbonyl)benzyl)-4-(oxetan-3-yl)piperazin-l -carboxamide

[0249] A solution of methyl 4-((7V-(3,4-dichlorophenyl)-4-(oxetan-3-yl)piperazin-l- carboxamido)methyl)-3-fluorobenzoate (0.170 g, 0.342 mmol) prepared in step 4 and hydrazine monohydrate (0.333 mL, 6.850 mmol) dissolved in ethanol (5 mL) at room temperature was stirred at 110°C for 18 hours, after which a reaction was finished by lowering the temperature to room temperature. Solvent was removed from the reaction mixture under reduced pressure, and then a title compound was used without an additional purification process (0.170 g, 100.0%, light yellow solid).

[0250] [Step 6] Synthesis of compound 4

[0251] 2,2-difluoroacetic anhydride (0.128 mL, 1.027 mmol) was added to a solution of N- (3,4-dichlorophenyl)-7V-(2-fluoro-4-(hydrazinecarbonyl)benzyl)-4-(oxetan-3-yl)piperazin-l- carboxamide (0.170 g, 0.342 mmol) prepared in the step 5 and imidazole (0.070 g, 1.027 mmol) dissolved in dichloromethane (4 mL) at room temperature, and heated under reflux for 18 hours, after which a reaction was finished by lowering the temperature to room temperature. Solvent was removed from the resulting mixture under reduced pressure, and then the resulting concentrate was purified via column chromatography (SiCb, 4 g cartridge; methanol / dichloromethane = 0 to 2.5%) and concentrated to obtain desired compound 4 (0.020 g, 10.5%) in a white solid form.

[0252] 'H NMR (400 MHz, CDCh) 6 7.89 (d, J= 7.8 Hz, 1H), 7.78 (d, J= 9.9 Hz, 1H), 7.68

[0253] (t, J = 7.3 Hz, 1H), 7.38 (d, J = 8.6 Hz, 1H), 7.23 (s, 1H), 7.06 - 6.80 (m, 2H), 4.95 (s, 2H), 4.64 (t, J= 6.1 Hz, 2H), 4.55 (t, J= 5.4 Hz, 2H), 3.45 - 3.42 (m, 1H), 3.34 - 3.33 (m, 4H), 2.18

[0254] - 2.17 (m, 4H); LRMS (ES) m / z 556.2 (M++ 1).

[0255] Examples 5 to 8: Synthesis of compounds 5 to 8

[0256] Compounds 5, 6, 7 and 8 according to examples 5, 6, 7 and 8 were prepared in accordance with the same reactions as described in steps 3 to 6 of example 4, respectively, except for using reactant A of table 2 below instead of 3, 4-di chlorophenyl isocyanate in step 3 of example 4, and using reactant B of table 2 below instead of methyl 4-(bromomethyl)-3- fluorobenzoate in step 4. The properties and yields of the products prepared in each of steps 3 to 6 in examples 5 to 8 are shown in table 2, and NMR data thereof are shown in table 3. In above table 3, compounds 5 , 6, 7, and 8 were prepared according to examples 5, 6, 7, and 8, respectively.

[0257] [Table 2]

[0258] [Table 3]

[0259] Protocol for measuring and analyzing activity of compound of present invention Experimental Example 1. Search for HD AC enzyme activity inhibition (in vitro) An experiment was conducted to identify the selectivity of the compound represented by formula I of the present invention to HDAC6 through an experiment on HDAC1 and HDAC6 enzyme activity inhibition.

[0260] The HD AC enzyme activity was measured with HD AC Fluorimetric Drug Discovery

[0261] Kit (BML-AK511, 516) of Enzo Life Science, Inc. For the test on the HDAC1 enzyme activity, human recombinant HDAC1 (BML-SE456) was used as an enzyme source and Fluor de Lys®

[0262] -“SIRT1 (BNL-KI177)” was used as a substrate. A five-fold dilution of the compound was divided into a 96-well plate, and then 0.3 pg of the enzyme and 10 pM of the substrate were inserted into each well and subjected to reaction at 30°C for 60 minutes, after which Fluor de I s(yj Developer II (BML-KI176) was inserted thereinto and subjected to reaction for 30 minutes and finished. After that, a fluorescence value (Ex 360, Em 460) was measured with a multi-plate reader (Flexstation 3, Molecular Device). An experiment on HDAC6 enzyme was conducted in accordance with the same protocol as in the HDAC1 enzyme activity test method by using human recombinant HDAC6 (382180) of Calbiochem Inc. For final result values, each ICso value was calculated with GraphPad Prism 4.0 program.

[0263] [Table 4]

[0264] As described in above table 4, it was confirmed from the results of testing the activity inhibition to HDAC1 and HDAC6 that 1,3,4-oxadiazole oxetane derivative compounds of the present invention, stereoisomers thereof or pharmaceutically acceptable salts thereof show an excellent selective HDAC6 inhibitory activity about 517 to about 1207 times.

[0265] Experimental Example 2. Analysis of HDAC6 inhibitory activity and other HDAC isotype selectivity in vitro)

[0266] The HDAC6 inhibitory potency and selectivity of a compound represented by compound 5 (compound of example 5: compound 5), and a compound represented by compound 1 (compound of example 1 : compound 1) were confirmed at an enzyme level. The present experiment was requested at Reaction biology Corp. (Malvern, PA, USA) and performed according to a test method established within the organization. Specifically, a serial dilution of the compound represented by compound 5 or the compound represented by compound 1 was divided into a plate, and then a substrate, i.e., RHK-K(Ac)-AMC and an enzyme were inserted together into 50 mM Tris-HCl buffer (pH 8.0, 137 mM NaCl, 2.7 mM KC1, 1 mM MgC12, 1 mg / ml BSA) to induce a reaction. After that, 50 mm Tris-HCl buffer (pH 8.0, 137 mMNaCl, 2.7 mM KCl, 1 mM MgC12) containing 2 mM nicotinamide and 16 mg / mL trypsin was inserted thereinto and then subjected to reaction. Then, a fluorescence signal was measured at Ex. 360 nm / Em. 460 nm to measure an enzyme activity, and then the results thereof are shown in table 5 below.

[0267] [Table 5]

[0268] It was confirmed that ICso for HDAC6 of the compound represented by compound 5 is 18.9 nM, while other HDAC isotypes are not inhibited at all. It was confirmed that ICso for HDAC6 of the compound represented by compound 1 is 60.0 nM, while other HDAC isotypes are not inhibited at all. In other words, it was confirmed that the compound represented by 13608 and the compound represented by compound 1 are compounds having excellent HDAC6 inhibitory activity and highly selective for HDAC6 compared to other HDAC isotypes. Experimental Example 3. Analysis of effect on axonal migration of mitochondria in vitro)

[0269] It has been reported that acetylation of tubulin, which is a component of microtubules, is reduced in various degenerative brain diseases, and it has been known that intracellular transport occurring through microtubules is damaged due to various other intracellular dysfunctions.

[0270] HDAC6 is an enzyme which plays a role in removing the acetylation of tubulin, and when the enzyme is inhibited, it has been known that the acetylation of tubulin increases to stabilize the microtubules and have a positive effect on intracellular transport and axonal transport.

[0271] An experiment on this example was conducted to confirm whether the compound represented by compound 5 (compound of example 5: compound 5), and the compound represented by compound 1 (compound of example 1 : compound 1) according to the present invention show an improvement effect on a relative velocity of mitochondria reduced by treatment with amyloid P protein fragment (AP), which is a substance causing dementia among neurodegenerative brain diseases, in neuronal axon by selectively inhibiting the HDAC6 activity to increase acetylation of tubulin, which is a main substrate of HDAC6.

[0272] Specifically, a hippocampal tissue of a mouse embryo obtained from an ICR pregnant mother mouse was subjected to single cell suspension, and then hippocampal neurons were cultured in a culture vessel for imaging coated with an extracellular matrix for seven days. After seven days of culture, the mouse hippocampal neurons were treated with Ap at a concentration of 1 pM. In 24 hours later, the resulting neurons were treated with the compound represented by compound 5 and the compound represented by compound 1 at a concentration of 0.3 pM for three hours, after which migration of stained mitochondria was photographed at a low speed through automated cell photographing equipment, so as to measure a migration distance per unit time, thereby evaluating a degree of intracellular transport.

[0273] Images were taken for one minute at one-second intervals to measure a relative velocity per second of each mitochondria. After setting a section in which a relative velocity of mitochondria is significantly reduced compared to vehicle in the normal group in the amyloid P-treated group, the results of normalization into a vehicle group are shown in table 6 below.

[0274] [Table 6]

[0275] In above table 6, Nomal refers to a normal group treated with only vehicle (0.5%

[0276] DMSO) without treatment with amyloid P (AP), and vehicle in amyloid P refers to a group treated with only amyloid P and vehicle (0.5% DMSO).

[0277] As shown in above table 6, it could be seen that a relative velocity of mitochondria decreased in the Ap-treated neuronal group compared to the normal neuronal group is increased by three-hour treatment with the compound represented by compound 5 and the compound represented by compound 1, and thus, the relative velocity of mitochondria decreased in neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy is improved by treatment with the compound. Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including dementia and Alzheimer's disease.

[0278] Experimental Example 4. Analysis of effect on axonal relative velocity of mitochondria when treated for each concentration (in vitro)

[0279] An experiment on this example was conducted to confirm whether the compound represented by compound 5 (compound of example 5: compound 5) according to the present invention shows an improvement effect in a concentration-dependent way on a relative velocity of mitochondria reduced by treatment with amyloid P protein fragment (AP), which is a substance causing dementia among neurodegenerative brain diseases, in neuronal axon by selectively inhibiting the HDAC6 activity to increase acetylation of tubulin, which is a main sub strate of HD AC6.

[0280] Specifically, a hippocampal tissue of a mouse embryo obtained from a pregnant mother mouse was subjected to single cell suspension, and then hippocampal neurons were cultured in a culture vessel for imaging coated with an extracellular matrix for seven days. After seven days of culture, the mouse hippocampal neurons were treated with Ap at a concentration of 1 pM. In 24 hours later, the resulting neurons were treated with the compound represented by compound 5 at a concentration of 0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30 pM for three hours, after which migration of stained mitochondria was photographed at a low speed through a confocal microscope, so as to measure a migration distance per unit time, thereby evaluating a degree of intracellular transport.

[0281] Images were taken for one minute at one-second intervals to measure a relative velocity per second of each mitochondria. After setting a section in which a relative velocity of mitochondria is significantly reduced compared to the normal group in the amyloid P-treated group, the results of normalizing a normal group into 100% and a group treated with amyloid P only into 0% are shown in table 7 below and FIG. 1.

[0282] [Table 7]

[0283] In above table 7, Nomal refers to a normal group treated with only vehicle (0.5%

[0284] DMSO) without treatment with amyloid P (AP), and vehicle in amyloid P refers to a group treated with only amyloid P and vehicle (0.5% DMSO).

[0285] As shown in above table 7 and FIG. 1, it could be seen that a relative velocity of mitochondria decreased in the AP-treated neuronal group compared to the normal neuronal group is significantly increased in a dose-dependent way by three-hour treatment with the compound represented by compound 5, and thus, the relative velocity of mitochondria decreased in neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy is improved by treatment with the compound.

[0286] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including dementia and Alzheimer's disease.

[0287] Experimental Example 5. Analysis of duration of medicinal effect on axonal relative velocity of mitochondria (in vitro)

[0288] An experiment on this example was conducted to confirm a duration of an improvement effect on a relative velocity of mitochondria reduced by treatment with amyloid P protein fragment (AP) of the compound represented by compound 5 (compound of example 5: compound 5) according to the present invention.

[0289] Specifically, a hippocampal tissue of a mouse embryo obtained from a pregnant mother mouse was subjected to single cell suspension, and then hippocampal neurons were cultured in a culture vessel for imaging coated with an extracellular matrix for seven days. After seven days of culture, the mouse hippocampal neurons were treated with Ap at a concentration of 1 pM. In 24 hours later, the resulting neurons were treated with the compound represented by compound 5 at a concentration of 0.3 pM for three hours and replaced with fresh culture medium. After that, in order to confirm a persistence of medicinal effect over 2 to 24 hours while not treated with the compound, the migration of the stained mitochondria was slowly photographed through a confocal microscope, and a migration distance per unit time was measured to evaluate a degree of intracellular transport.

[0290] Images were taken for one minute at one-second intervals to measure a relative velocity per second of each mitochondria. After setting a section in which a relative velocity of mitochondria is significantly reduced compared to vehicle of the normal group in the amyloid P-treated group, the results of normalization into vehicle 100% and amyloid P-treated group 0% are shown in table 8 below and FIG. 2. [Table 8]

[0291] In above table 8, Nomal refers to a normal group treated with only vehicle (0.5% DMSO) without treatment with amyloid P (AP), and vehicle in amyloid P refers to a group treated with only amyloid P and vehicle (0.5% DMSO).

[0292] As shown in above table 8 and FIG. 2, it was confirmed that a relative velocity of mitochondria decreased in the AP-treated neuronal group compared to the normal neuronal group is significantly increased by three-hour treatment with the compound represented by compound 5, and a medicinal effect thereof significantly continues for up to nine hours even after the compound is removed through replacement with a new culture medium.

[0293] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including dementia and Alzheimer’s disease.

[0294] Experimental Example 6. Analysis of effect on axonal relative velocity of mitochondria damaged in tauopathy-like situation in vitro)

[0295] In order to confirm a therapeutic effect of the compound represented by compound 5 (compound of example 5: compound 5) on degenerative brain diseases, a cell model of tauopathy was prepared and treated with the compound of the present invention, and then an experiment of this example was conducted to confirm a duration of an improvement effect on a decreased relative velocity of mitochondria.

[0296] Tau protein is known to bind to microtubules constituting nerve cells, thus contributing to maintenance of stability of the microtubules, and in pathological conditions such as tauopathy, Tau protein is separated from the microtubules, which become then unstable and adversely affect various cell functions. Microtubules serve as a road which mediates the movement of various organelles, vesicles, and various substances required for cellular homeostasis in nerve cells, and in tauopathy conditions, such intracellular transport may not occur normally due to instability of these microtubules. A test system was constructed using supercultured cells of mice with overexpressed human tau proteins having a P301L mutation which promotes aggregation and detachment from the microtubules, and in this test system, it was evaluated whether the compound represented by compound 5 improves microtubule normalization and intracellular transport.

[0297] Specifically, a cerebral cortex tissue of a mouse embryo obtained from a pregnant mother mouse was subjected to single cell suspension, and then transfected with a P301L mutant human tau protein expression vector using electroporation. After seven days of culture in a cell incubator, the resulting cells were treated with the compound represented by compound 5 at a concentration of 0.01, 0.1, 0.3, 1, 3, 10 pM for three hours, after which migration of stained mitochondria was photographed at a low speed through a confocal microscope, so as to measure a migration distance per unit time, thereby evaluating a degree of intracellular transport. All results were indicated as mean ± standard error, and the validity of medicinal effect was determined through statistical significance between negative control group and each test substance group. Statistical analysis was performed to confirm the homogeneity of dispersion using one-way ANOVA, and when a p value was less than 0.05 by Dunnett post test, it was determined to be statistically significant, and the test results are shown in table 9 below and FIG. 3.

[0298] [Table 9]

[0299] In above table 9, P301L_Tau (-) refers to a group treated with only vehicle (0.5% DMSO) as a normal neuronal group transfected with a control vector which does not cause tauopathy, and P301L_Tau (+) refers to a group treated with only vehicle (0.5% DMSO) as a disease neuronal group transfected with a P301L mutant human tau protein expression vector.

[0300] As shown in above table 9 and FIG. 3, it could be seen that a relative velocity of mitochondria decreased in the P301L_Tau (+) group compared to the P301L_Tau (-) group is significantly increased in a dose-dependent way by three-hour treatment with the compound represented by compound 5, and thus, the relative velocity of mitochondria decreased in a tauopathy state is improved by treatment with the compound of the present invention.

[0301] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy.

[0302] Experimental Example 7. Analysis of HDAC6 inhibitory activity and selectivity at neuronal level (in vitro)

[0303] The HDAC6 inhibitory efficacy and selectivity of the compound represented by compound 5 (compound of example 5: compound 5), and the compound represented by compound 1 (compound of example 1 : compound 1) were confirmed at a neuronal level.

[0304] An experiment of this example was conducted to confirm whether the compound represented by compound 5 and the compound represented by compound 1 according to the present invention selectively inhibit HDAC6 activity in nerve cells to increase the acetylation of tubulin, which is a main substrate of HDAC6.

[0305] Specifically, SH-SY5Y cells, a human neuroblastoma, were attached to a culture dish and cultured in an incubator for 24 hours. After culture for one day, SH-SY5Y cells were treated with the compound represented by compound 5 and the compound represented by compound 1 at a concentration of 0.1, 0.3, and 1 pM for three hours. The cells were chemically crushed using RIPA buffer, and then the extracted proteins were arranged for each protein size on a polyacrylamide gel by SDS-PAGE technique. The proteins on the gel were transferred to a nitrocellulose membrane using an electrophoresis method, and an antibody selectively binding to the protein to be observed was reacted and visualized in a band form to measure a degree of expression, and the results are shown in FIGS. 4 and 5. In above FIGS. 4 and 5, con refers to a result of a cell which is not treated with the compound of the present invention.

[0306] As can be confirmed from above FIGS. 4 and 5, it was confirmed that the compound represented by compound 5 and the compound represented by compound 1 significantly increase the acetylation of tubulin.

[0307] Thus, it can be seen that the compounds according to the present invention exhibit an excellent effect of increasing the acetylation of tubulin.

[0308] Experimental Example 8. Analysis of brain permeability of HDAC6-specific inhibitor (in vivo)

[0309] In order to see a therapeutic effect of the compound on degenerative brain diseases, the compound exposed to the blood needs to penetrate a brain-blood barrier (BBB) and reach nerve cells in a brain tissue.

[0310] An experiment on this example was conducted to confirm whether the compound represented by compound 5 (compound of example 5: compound 5), and the compound represented by compound 1 (compound of example 1 : compound 1) according to the present invention are absorbed in the stomach, penetrate the brain-blood barrier (BBB) and reach nerve cells in a brain tissue when orally administered.

[0311] Specifically, ICR mice were orally administered once with the compound represented by compound 5 at a concentration of 10 mg / kg, and blood and brains were collected after 0.5, 2, or 4 hours. A remaining concentration of the compound represented by compound 5 was measured in the plasma and brain tissues of the harvested mouse blood by the LC-MS / MS technique (see Rapid Commun. Mass Spectrom. 14, 1729-1735 (2000)). ICR mice were orally administered once with the compound represented by compound 1 at a concentration of 50 mg / kg, and blood and brains were collected after 0.5, 2, or 4 hours. A remaining concentration of the compound represented by compound 1 was measured in the plasma and brain tissues of the harvested mouse blood by the LC-MS / MS technique and the results thereof are shown in table 10.

[0312] All results were expressed as mean± a standard deviation of mean, a unit of compound concentration in the brain is ng / g, and that of compound concentration in the plasma is ng / mL.

[0313] [Table 10]

[0314] As shown in above table 10, it was confirmed that the compound represented by compound 5 and the compound represented by compound 1 have a B / P ratio of 0.3 or more, and thus have high brain permeability properties.

[0315] Thus, it can be seen that the compounds according to the present invention show excellent brain permeability, and thus exhibit an excellent effect of preventing and treating nerve diseases, such as brain diseases, central nervous system atrophy, hereditary nerve diseases, or the like.

[0316] Experimental Example 9. Animal behavioral evaluation (cognitive function evaluation)

[0317] The most significant symptom of neurodegenerative diseases is cognitive dysfunction, and various evaluation tools for evaluating cognitive function of patients are used in actual clinical trials (MoCA, MMSE, CDR., ADAS-cog, etc.). In animal experiments, Y-shape maze, passive avoidance test, and water maze test are mainly used as cognitive / 1 earning evaluation methods.

[0318] In order to confirm a therapeutic effect on cognitive dysfunction caused by neurodegeneration, a medicinal effect was confirmed in tauopathic mice (PS 19) which were developed by transformation of tau, a causative protein of Alzheimer's disease and tauopathy.

[0319] Tauopathy is one of the representative degenerative brain diseases, and tau, the causative protein, is known to be involved in the development of at least ten degenerative brain diseases. Tauopathy is a disease which develops in people with several mutations in MAPT, a causative gene of tauopathy.

[0320] Tau protein is known to bind to microtubules constituting nerve cells, thus contributing to maintenance of stability of the microtubules, and in pathological conditions such as tauopathy, Tau protein is separated from the microtubules, which become then unstable and adversely affect various cell functions.

[0321] PS 19 tauopathic mice are disease model animals showing clinical symptoms of patients with tauopathy, such as an increase in intracerebral tau and phosphorylated tau proteins, a decrease in memory and cognitive function, and a decrease in motor function due to an overexpression of human P301S mutant tau protein which promotes an aggregation of tau proteins and a detachment from the microtubules.

[0322] The compound of the present invention was orally administered to PS 19 tauopathic mice twice a day, and 30 minutes after administration of the test substance, the following behavioral test was performed.

[0323] Y-maze test

[0324] A Y-maze test was conducted to evaluate the ability to act sequentially in an experiment for measuring short-term memory. The measuring equipment consists of three parts, each of which has a length of 42 cm, a width of 3 cm, a height of 12 cm, and a folding angle of 120° for the three parts. This device consisted of a white polyvinyl plastic, and the experiment was conducted after setting three branches as A, B, and C, respectively. Experimental animals were put and 1 point (actual alternation) was given each by counting the number of times when the animals enter each branch fully even with the tail thereof entering therein and the case of sequentially entering each branch for eight minutes. An alternation behavior is defined as entering all three branches without overlapping, and spontaneous alternation behavior was calculated by the following equation, and the results thereof are shown in FIGS. 6 to 8.

[0325] In above FIGS. 6 to 8, WT (littermate) is a mouse of a normal group orally dosed with 0.5% methyl cellulose, PS19 (vehicle littermate) is a PS19 mouse (control group) orally dosed with 0.5% methyl cellulose, and PS19+compound 5 is a group of PS 19 mice orally dosed with the compound represented by compound 5.

[0326] As confirmed from FIG. 6, as a result of repeatedly administering (orally) compound 5 (compound of Example 5: compound 5) to 12-week-old tauopathic (PS19) mice for eight weeks, it could be seen that an alternation behavior value significantly increases compared to the control group (littermate (vehicle PS 19) dosed with 0.5% methyl cellulose), thus showing that a cognitive function decline caused by tauopathy is ameliorated.

[0327] As confirmed from FIG. 7, as a result of repeatedly administering (orally) compound 5 (compound of Example 5: compound 5) to 12-week-old tauopathic (PS 19) mice for 16 weeks, it could be seen that an alternation behavior value increases compared to the control group (littermate (vehicle PS 19) dosed with 0.5% methyl cellulose), thus showing that a cognitive function decline caused by tauopathy is ameliorated.

[0328] As confirmed from FIG. 8, as a result of repeatedly administering (orally) compound 1 (compound of example 1 : compound 1) to 28-week-old tauopathic (PS19) mice for eight weeks, it could be seen that an alternation behavior value increases compared to the control group (littermate (vehicle PS19) dosed with 0.5% methyl cellulose), thus showing that a cognitive function decline caused by tauopathy is ameliorated.

[0329] Accordingly, it can be seen that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy.

[0330] Experimental Example 10. Histopathological analysis

[0331] After the test substance was administered to the PS 19 mice as in experimental example 9, a histopathological analysis was performed on the brain tissue after the substance administration was terminated. At 0.5 hours after a final administration of compound 5 (compound of example 5: compound 5), the mice were anesthetized with isofl orane, and then the brains were extracted. For double immunofluorescence staining, the brain tissue sections were washed twice with phosphate buffered saline (PBS) for 15 minutes, and reacted with blocking solution, in which bovine serum albumin (Sigma, USA) was mixed with PBS, for two hours. After washing twice with PBS, primary antibodies were diluted with PBS containing Triton x-100 (0.3%) and normal donkey serum (5%), respectively, and reacted overnight at 4°C. Anti-phospho-Tau (Ser202, Thr205)), monoclonal antibody (clone AT8, 1 : 300, Invitrogen, MN1020) and anti-NeuN polyclonal antibody (1 :300, Invitrogen, PA5-78499) were used as the primary antibodies. After that, the tissues were washed with PBS, and reacted with secondary antibodies, Alexa488-tagged donkey anti-mouse IgG (1 :500, Jackson Immunoresearch, 715-545-150, for phospho-tau) and Cy3-tagged donkey anti-mouse IgG (1 :500, Jackson Immunoresearch, 711-165-152, forNeuN) at room temperature for three hours. Then, the tissues were washed again with PBS, attached to a coated slide, sufficiently dried, and sealed with a DAPI-containing sealing agent (VECTASHIELD® Antifade Mounting Mediu m with DAPI, H-1200-10, Vector Laboratories) to prepare a tissue sample.

[0332] A stained brain tissue was photographed using a confocal microscope, and a staining intensity of AT8 for each brain tissue region was measured in the photographed region using the image J program, and the results thereof are shown in FIGS. 9 to 13.

[0333] In above FIGS. 9 to 13, WT (littermate) is a mouse of a normal group dosed with 0.5% methyl cellulose, PS 19 (vehicle littermate) is a PS 19 mouse (control group) dosed with 0.5% methyl cellulose, and PS19+compound 5 is a group of PS19 mice dosed with the compound represented by compound 5.

[0334] As confirmed from above FIGS. 9 to 13, as a result of making a histopathological analysis for each mouse brain region after repeatedly administering the compound represented by compound 5 to 12-week-old tauopathic (PS19) mice for eight weeks, it was observed that a degree of hyperphosphorylation (AT8, S202 / T205) of transformed tau is significantly higher in mice of the control group (vehicle littermate) compared to mice of the normal group (WT littermate). On the contrary, it was confirmed that animals dosed with the compound represented by compound 5 show significantly ameliorated hyperphosphorylation of tau in mice of the control group.

[0335] As such, it can be seen that the compound represented by compound 5 ameliorates the hyperphosphorylation of tau observed in PS 19 mice.

[0336] Accordingly, it can be seen that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy.

[0337] Experimental Example 11. Electrophysiological analysis

[0338] After the test substance was administered to the PS 19 mice as in experimental example 9, a Electrophysiological analysis was performed on the brain tissue after the substance administration was terminated. At 0.5 hours after a final administration of compound 5 (compound of example 5: compound 5), the mice were anesthetized, and then the brains were extracted. The extracted brain was sliced to a thickness of 300 pm to prepare a tissue section containing a hippocampus, and was transferred to a recording chamber perfused with artificial cerebrospinal fluid (30-32°C) and proceeded.

[0339] A field excitatory postsynthetic potential (fEPSP) record was obtained using a DAM80 amplifier and WinLTP2.10 software (University of Bristol), filtered by 1kHz, and sampled at 20kHz. A recording pipette with a resistance of 1-3 M was filled with the artificial cerebrospinal fluid. All fEPSPs were recorded on a Schaffer collateral pathway (CA3-to-CAl synapses) by stimulation with two bipolar electrical stimulators (FHCs) placed in a radial layer or by stimulation with a 20 sec inter-stimulus interval (ISI). A theta burst stimulation (TBS) was given as a stimulation heat of 100 Hz (5 pulses, 20 times) at intervals of 5 Hz. A success of LTP induction was confirmed by statistical comparison of the mean fEPSP slope / amplitude measured for 50-60 minutes after the TBS with the mean fEPSP slope / amplitude measured for 10 minutes before the TBS. An analysis of data was performed using WinLTP 2.10 reanalysis software (University of Bristol). All data were expressed as mean± a standard error of mean(SEM) and a statistical analysis was performed using SPSS statistical version 21 (IBM). Student's t-test was used for a significance test when comparing two groups, ANOVA was used for the significance test for group comparison, LSD post-analysis was performed, and the results thereof are shown in FIGS. 14 and 15.

[0340] A significance level was set to p<0.05. It means * or §, p<0.01; ** or §§, p<0.01; ***or§§§, P<0.001.

[0341] In above FIG. 15, in case of 7 / 2, 7 means the number of slices of brain tissue, and 2 means the number of mice which have undergone evaluation. In case of 14 / 4, 14 means the number of slices of brain tissue, and 4 means the number of mice which have undergone evaluation.

[0342] In above FIGS. 14 and 15, WT (littermate) is a mouse of a normal group orally dosed with 0.5% methyl cellulose, PS19 (vehicle littermate) is a PS19 mouse (control group) orally dosed with 0.5% methyl cellulose, and PS19+compound 5 is a group of PS 19 mice orally dosed with the compound represented by compound 5. As confirmed from above FIGS. 14 and 15, it was confirmed that a hippocampal magnitude of the LTP of the control group is significantly decreased as compared with the normal group. This means that a neurological pathway associated with memory is degraded. On the contrary, as a result of repeatedly (orally) administering the compound represented by compound 5 to 12-week-old tauopathic (PS19) mice for 16 weeks, it was confirmed that enhanced hippocampal long-term memory is significantly recovered as compared with the control group (littermate (vehicle PS 19) dosed with 0.5% methyl cellulose).

[0343] Accordingly, it can be seen that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy.

[0344] Experimental Example 12. Animal behavioral evaluation (motor function evaluation)

[0345] In order to confirm a therapeutic effect of the compound represented by 13524 (compound of example 1 : compound 1) and the compound represented by compound 5 (compound of example 5: compound 5) on degenerative brain diseases, the compound was administered to Yacl28 mice, which were Huntington's disease model mice, and then an improvement of animal motor function was evaluated. Huntington's disease is one of the representative degenerative brain diseases, and is a genetic disease which causes patients to die within 15 to 25 years after the outbreak due to serious physical and mental incapacity. Huntington's disease is an autosomal dominant disease which develops in people who have a mutation in which a CAG sequence repeats 40 times or more in HTT, the gene responsible for Huntington's disease.

[0346] Yacl28 is a Huntington's disease model mouse in which a human mutant HTT gene with 128 CAG sequences repeated is inserted, and is a disease model animal which exhibits clinical symptoms of Huntington's disease patients, such as an expression of human mutant HTT transcripts and proteins, a death of striatum, and a deterioration of motor functions such as muscle strength and limb coordination.

[0347] Specifically, the compound represented by compound 1 was orally administered to six- month-old Yacl28 mice at 5, 20 mg / kg twice a day for eight weeks, and the compound represented by compound 5 was repeatedly orally administered at 1, 3, 10, 30 mg / kg twice a day for 12 weeks, and a motor function evaluation was performed at intervals of four weeks, and the results thereof are shown in FIGS. 16 to 19.

[0348] In above FIGS. 16 to 19, all results were indicated as mean ± standard error, and the validity of medicinal effect was determined through statistical significance between Yacl28 mouse control group and each test substance group. As for statistical analysis, the homogeneity of dispersion was identified with ANOVA (one-way ANOVA for single measurement and two- way ANOVAfor repeated measurement). As a result of Dunnett or Bonferroni post test, it was determined as statistically significant, if p value is less than 0.05. Accelerating rotarod and grip strength tests were performed once a day for two days. After that, group separation was performed by a Z-array method based on the test results. Yacl28 mice were divided into the vehicle administration group and the compound administration group (compound represented by compound 1 : 5, 20 mg / kg, compound represented by compound 5: 1, 3, 10, 30 mg / kg, orally administered), and the mice in each group were 18 mice. The test substance was orally administered twice a day for eight and 12 weeks, and an exercise function was evaluated once a day for two days at four-week intervals during the administration.

[0349] Accelerating rotarod test

[0350] An accelerating rotarod test (ROTAROD, LE8205, Panlab) was performed to evaluate a motor coordination function / motor function. Before the test, all test animals were placed on a rod which accelerated from 4 to 20 rpm three times a day for three days to train for adaptation for about three weeks, and animals which took a time of 180 seconds or more to fall off the rod were used for the test. In this experiment, the time for an animal to fall off the rod accelerating from 4 to 40 rpm was measured for three minutes. A total of six accelerating rotarod tests were conducted three times a day for two consecutive days, and a maximum value among six measured values was used. The results thereof are shown in FIGS. 16 and 17.

[0351] In above FIGS. 16 and 17, WT (wild type) refers to a normal mouse to which vehicle (0.5% methyl cellulose) was orally administered, Yacl28 means a control group of Huntington's disease model mice to which vehicle was orally administered, Yacl28+compound 5 indicates a group in which the compound represented by compound 5 was orally administered to Yacl28 mice, and Yacl28+compound 1 represents a group in which the compound represented by compound 1 was orally administered to Yacl28 mice.

[0352] As shown in above FIG. 16, a latency to fall, which was decreased in the Yacl28 control group compared to the normal mouse, was significantly increased by administering the compound represented by compound 1 at a dose of 20 mg / kg for four weeks.

[0353] In addition, as shown in FIG. 17, it could be seen that the latency to fall, which has been decreased in the Yacl28 control group compared to the normal mouse, is significantly increased from a time when the compound represented by compound 5 is administered at a dose of 3 mg / kg for one week, and the latency to fall is significantly increased in most cases in a longer administration period or at a higher concentration, and thus an exercise loss, which is a symptom of Huntington's disease, is ameliorated by the administration of the compound of the present invention.

[0354] Accordingly, it can be seen that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Huntington's disease.

[0355] Grip strength test

[0356] A grip strength test (BIO-GS3, BIOSEB) was performed to evaluate the muscular strength. The grip strength test evaluated the force of two front feet of a mouse using a bar. All the experiments were performed by one person. When the mouse grips, the tail is gently pulled to have a grip strength, and then is pulled at a slope of 15° to measure a maximum tension. A total of ten grip strength tests were performed five times a day for two days in a row, and an average of these values was used, and the results thereof are shown in FIGS. 18 and 19.

[0357] In above FIGS. 18 and 19, WT (wild type) refers to a normal mouse to which vehicle was administered, Yacl28 means a control group of Huntington's disease model mice to which vehicle was administered, Yacl28+compound 5 indicates a group in which the compound represented by compound 5 was administered to Yacl28 mice, and Yacl28+compound 1 represents a group in which the compound represented by compound 1 was administered to Yacl28 mice.

[0358] As shown in above FIG. 18, a grip force, which was decreased in the Yacl28 control group compared to the normal mouse, was significantly increased in a dose-dependent way by administering the compound represented by compound 1 for eight weeks. In addition, as shown in above FIG. 19, it could be seen that the grip force, which has been decreased in the Yacl28 control group compared to the normal mouse, is significantly increased by administering the compound represented by compound 5 for 12 weeks, and is significantly increased in the administered groups of all concentrations, and thus a decrease in muscular strength, which is a symptom of Huntington's disease, is ameliorated by the administration of the compound.

[0359] Accordingly, it can be seen that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Huntington's disease.

[0360] Experimental Example 13. Analysis of effect on increased axonal relative velocity of mitochondria damaged in Charcot-Marie- Tooth disease (CMT, HMSN, hereditary motor and sensory neuropathy) (in vitro)

[0361] In order to confirm a therapeutic effect of the compound represented by compound 5 (compound of example 5: compound 5), and the compound represented by compound 1 (compound of example 1 : compound 1) on CMT disease, an experiment on this example was conducted to confirm an improvement effect on a movement velocity of mitochondria decreased in the axon of neurons isolated from the dorsal root ganglion of a nine-month-old MFN2 mutant mouse with CMT2A type Charco-Marie-Tooth disease induced according to treatment with the compound of the present invention.

[0362] After three days of culture in a cell incubator, mouse neuron cells obtained by separating dorsal root ganglia (DRG) from a nine-month-old MFN2 mutant mouse were treated with the compounds represented by compound 5 and compound 1 at a concentration of 100 and 300 nM for three hours, and then a migration of stained mitochondria was slowly photographed through a confocal microscope to measure a migration distance per unit time, thereby evaluating a degree of intracellular transport.

[0363] Results were indicated as mean ± standard error, and the validity of medicinal effect was determined through statistical significance between negative control group and each test substance group. Statistical analysis was performed to confirm the homogeneity of dispersion using one-way ANOVA, and when a p value was less than 0.05 by Dunnett post test, it was determined to be statistically significant.

[0364] In addition, after setting a section in which a relative velocity of mitochondria is significantly reduced in MFNR94Qmice DRG as compared with the normal group (WT DRG), normalization was made into normal group 100% and MFNR94Qmice DRG 0%, and the test results are shown in table 11 below and FIG. 20.

[0365] In above table 11, WT refers to a group in which vehicle (0.5% methyl cellulose) was administered to a normal mouse, and MFNR94Qmice DRG means a group in which only vehicle (0.5% methyl cellulose) was administered to an MFN2 mutant mouse (group with induced CMT2A-type Charcot-Marie-Tooth disease).

[0366] [Table 11]

[0367] As shown in above table 11 and FIG. 20, it could be seen that a relative velocity of mitochondria decreased in the MFN2 mutant control group compared to the WT group is significantly increased by three-hour treatment with the compounds represented by compound 1 and compound 5, and thus, the relative velocity of mitochondria decreased in a CMT condition is improved by treatment with the compound of the present invention.

[0368] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot-Marie-Tooth disease.

[0369] Experimental Example 14. Confirmation of therapeutic effect on CMT

[0370] The CMT is the most common type of hereditary peripheral nerve disorder caused by a mutation of proteins which constitute nerves. More than 1,000 mutations have been identified from about 90 genes so far (Timmerman et al., (2014) Genes 5:13-32). Upon the development of Charcot-Marie-Tooth (CMT) disease, a progressive degeneration of peripheral nerves leads to atrophy of muscles affected by neural distribution, and thus patients show a gradual atrophy in their muscles of hands and feet as well as a symptom of deformed hands and feet. The CMT is genetically and clinically very diverse and complicated, and it is known that symptoms thereof vary ranging from a close-to-normal state to a wheelchair-bound state depending on mutation types. The CMT emerges mainly in teen years and occurs to one for every 2,500 people (Krajewski et al., (2000) Brain 123: 1516).

[0371] The CMT belongs to rare diseases as a hereditary peripheral nerve disorder. However, a prevalence rate thereof amounts to one for every 2,500 people. There are about 20,000 patients in South Korea and 2,800,000 ones worldwide. Until now, a therapy for the CMT is limited only to rehabilitation, aids, pain control, surgical therapy, etc., but a successful therapeutic agent has not been developed yet. Thus, there is a great need for developing a therapeutic agent for the CMT.

[0372] For example, with regard to the CMT, which is the most common type of hereditary motor and sensory neuropathy, a large-scale clinical trial was conducted on ascorbic acid, which had been proven as an essential material for myelination in the peripheral nervous system through an experiment on culturing lemmocytes and dorsal root ganglion cells together, but such trial was failed in proving validity (Pareyson et al., (2011) 10(4):3205). In particular, in the case of certain types of diseases such as CMT1X, CMT2A, etc., a gene causing the diseases is highly expressed in the central nervous system. Indeed, it has been confirmed that approximately 10% of patients have symptoms such as atrophy of certain brain tissues including the optic nerve and visual impairment, and thus an importance of drug action in the central nervous system is also mentioned.

[0373] As described above, the compound of the present invention may pass through the brain barrier, and thus may exhibit a therapeutic effect on Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) as well as a therapeutic effect on Charcot- Marie-Tooth disease (CMT) associated with the central nervous system (CNS).

[0374] Thus, in the following research on two types of CMT disease model, it was confirmed that the compound of the present invention may be advantageously used for prevention and treatment of the CMT by remarkably improving motor and sensory functions (rotarod and balance beam tests) of CMT mice.

[0375] 14.1 Evaluation of motor and sensory functions

[0376] In hereditary neurological diseases such as Charcot-Marie-Tooth disease (CMT), damage to the nervous system causes gait disorders, loss of sensation, decreased limb coordination, and the like. In clinical studies with patients, various evaluation tools such as walking 6 meters, evaluating sensory functions according to the position of the arms and legs, fastening buttons, etc., were used to evaluate such functional defects. In addition, in animal experiments, the rotarod test, balance beam test, grip strength test, and the like are mainly used as methods for evaluating symptoms due to such damage to the nervous system.

[0377] In the corresponding research, in order to confirm a therapeutic effect of the compound represented by compound 5 (compound of example 5: compound 5) on motor and sensory functions in CMT diseases, the compound was administered to two types of CMT disease model mice (CX32 null mice, MFN2 mutant mice), and then an improvement effect on the corresponding functions of the animals was evaluated.

[0378] 14.1.1 CX32 null mouse study results

[0379] First, a five-month-old CX32 null mouse was orally dosed with the compound represented by compound 5 at 10 mg / kg twice a day for five months, and the motor and sensory functions were evaluated during an administration period. The results thereof are shown in FIGS. 21 to 22.

[0380] In FIGS. 21 to 22 below, all results were indicated as mean ± standard error, and the validity of medicinal effect was determined through statistical significance between normal group (WT) and each test substance group. As for statistical analysis, the homogeneity of dispersion was identified with ANOVA (one-way ANOVA for single measurement and two- way ANOVAfor repeated measurement). As a result of Dunnett or Bonferroni post test, it was determined as statistically significant, if p value is less than 0.05.

[0381] For the grouping of the corresponding study, the animals were divided into each group according to the Z-array method based on the body weight of animals before drug administration, values derived from constant rotarod and balance beam test results as shown in table 12 below. Mice were orally dosed with the vehicle (0.5% methyl cellulose) or 10 mg / kg of the compound represented by compound 5 according to a defined group.

[0382] Male CX32 null mice used for the corresponding study were provided with a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with a temperature (22 ± 2°C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed according to the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (with an approved number: S-22 016).

[0383] [Table 12]

[0384] Constant rotarod test

[0385] The rotarod test (LE 8205, Panlab) was performed to evaluate forced motor activity and coordination function. For adaptation, all test animals were trained for adaptation at 8 rpm five times a day over a three-day course, and additionally trained for adaptation at 12 rpm five times a day for two days. The animals satisfying a category of latency to fall of 100-180 seconds were used for further experiments (about 80% of the animals satisfied said category). The latency to fall was measured three times at a fixed speed of 12 rpm for three minutes. The rotarod test was repeated three times for each experiment and the maximum value of the three measured values was used as a test result (latency to fall). In above FIG. 21, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, CX32 null mice mean a CMT disease model mouse control group to which vehicle was orally administered, and CX32 null mice+compound 5 represents a group in which the compound represented by compound 5 was orally administered to a CMT disease mouse (CX32 null mouse) with CX32 knocked out.

[0386] As a result, as shown in FIG. 21, it was confirmed that the compound of the present invention exhibits an effect of remarkably enhancing the latency to fall in CX32 null mice.

[0387] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease of Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Marie-Tooth disease (CMT) associated with the central nervous system (CNS).

[0388] Balance beam test

[0389] The balance beam test was performed to measure a motor coordination function and a unique sense of limbs. A rod (1.2 cm wide, 0.6 cm high, and 1.0 m long) was fixed at an inclination of 9° (45 cm high from a starting point and 60 cm high from an ending point). At the starting point, a mouse was stimulated with a light of 60 W and an ending point was equipped with a dark box without light so that the mice could feel a sense of relief. All experimental animals were acclimatized 30 minutes before an evaluation under the same conditions as the experimental conditions. The mouse was placed at the starting point to walk toward the ending point, and the number of slips after departure was measured. Before the test, the mouse was trained three times a day for two days and the results on day 3 were used for grouping. Each experiment was independently evaluated by two individuals and the results thereof are shown in FIG. 22.

[0390] In above FIG. 22, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh means a CMT disease model mouse control group in which vehicle was orally administered to CX32 null mice, and compound 5 represents a group in which the compound represented by compound 5 was orally administered to a CMT disease mouse (CX32 null mouse) with CX32 knocked out.

[0391] As shown in FIG. 22, it was confirmed that the compound of the present invention exhibits an effect of remarkably reducing a slip count and a transverse time of the rod.

[0392] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease of Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Marie-Tooth disease (CMT) associated with the central nervous system (CNS).

[0393] 14.1.2 MFN2 mutant mouse study results

[0394] A six-month-old MFN2 mutant mouse was orally dosed with the compound represented by compound 5 at 10 mg / kg twice a day for three months, the motor and sensory functions were evaluated during an administration period, and the results thereof are shown in FIGS. 23 to 24. The expression and statistical processing method for the corresponding results were conducted in the same manner as the study of CX32 null mice of above 14.1.1,

[0395] For the grouping of the corresponding study, the animals were divided into each group according to the Z-array method based on the body weight of animals before drug administration, values derived from accelerating rotarod and balance beam test results as shown in table 13 below. Mice were orally dosed with the vehicle (0.5% methyl cellulose) or 10 mg / kg of compound 5 according to a defined group.

[0396] Male MFN2 mutant mice used for the corresponding study were provided with a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with a temperature (22 ± 2°C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed according to the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (with an approved number: S-22_012).

[0397] [Table 13]

[0398] Accelerating rotarod test

[0399] An accelerating rotarod test (LE8205, Panlab) was performed to evaluate a motor coordination function / motor function. Before the test, all test animals were placed on a rod which accelerated from 4 to 20 rpm three times a day for three days to train for adaptation for about three weeks, and animals which took a time of 180 seconds or more to fall off the rod were used for the test. In this experiment, the time for an animal to fall off the rod accelerating from 4 to 40 rpm was measured for three minutes. A total of three accelerating rotarod tests were conducted for one day, and a maximum value among three measured values was used. The results thereof are shown in Fig. 23.

[0400] In above FIG. 23, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to MFN2 mutant mice, and compound 5 represents a group in which the compound represented by compound 5 was orally administered to an MFN2 mutant mouse.

[0401] As a result, as shown in FIG. 23, it was confirmed that the compound of the present invention exhibits an effect of remarkably enhancing the latency to fall.

[0402] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0403] Balance beam test

[0404] A balance beam test was performed to measure a motor coordination function and a unique sense of limbs, and a research method was performed in the same manner as the CX32 null mouse study of above 14.1.1, and the results thereof are shown in FIG. 24.

[0405] In above FIG. 24, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to MFN2 mutant mice, and compound 5 represents a group in which the compound represented by compound 5 was orally administered to an MFN2 mutant mouse.

[0406] As shown in above FIG. 24, it was confirmed that the compound of the present invention exhibits an effect of remarkably reducing a slip count.

[0407] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0408] 14.1.3 CMT2A mouse study results

[0409] A six-month-old CMT2A mouse (mutant Mfn2R94Q) was orally dosed with the compound represented by compound 5 of Example 5 at 10 mg / kg twice a day for three months, the motor and sensory functions were evaluated during an administration period, and the results thereof are shown in FIGS. 25 to 26. The expression and statistical processing method for the corresponding results were conducted in the same manner as the study of CX32 null mice of above 14.1.1,

[0410] For the grouping of the corresponding study, the animals were divided into each group according to the Z-array method based on the body weight of animals before drug administration, values derived from accelerating rotarod and balance beam test results as shown in table 13 below. Mice were orally dosed with the vehicle (0.5% methyl cellulose) or 10 mg / kg of compound 5 according to a defined group.

[0411] Male CMT2A mice used for the corresponding study were provided with a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with a temperature (22 ± 2°C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed according to the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (with an approved number: S-22_012).

[0412] [Table 14]

[0413] Accelerating rotarod test

[0414] An accelerating rotarod test (ROTAROD, LE8205, Panlab) was performed to evaluate a motor coordination function / motor function. Before the test, all test animals were placed on a rod which accelerated from 4 to 20 rpm three times a day for three days to train for adaptation for about three weeks, and animals which took a time of 180 seconds or more to fall off the rod were used for the test. In this experiment, the time for an animal to fall off the rod accelerating from 4 to 40 rpm was measured for three minutes. A total of three accelerating rotarod tests were conducted for one day, and a maximum value among three measured values was used. The accelerated rotarod test was conducted for 3 months and AUC data (period x measured value in the rotarod test) obtained using prism file are shown in Fig. 25.

[0415] In above FIG. 25, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to CMT2A mice, and compound 5 represents a group in which the compound represented by compound 5 was orally administered to an CMT2A mouse.

[0416] As a result, as shown in FIG. 25, it was confirmed that the compound of the present invention exhibits an effect of remarkably enhancing the latency to fall.

[0417] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0418] Balance beam test

[0419] A balance beam test was performed to measure a motor coordination function and a unique sense of limbs, and a research method was performed in the same manner as the CX32 null mouse study of above 14.1.1, and the results thereof are shown in FIG. 2.

[0420] In above FIG. 26, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh (TG) means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to CMT2A mice, and compound 5 (TG) represents a group in which the compound represented by compound 5 (Example 5) was or6ally administered to an CMT2A mouse.

[0421] As shown in above FIG. 26, it was confirmed that the compound of the present invention (for example, compound 5 of Example 5) exhibits an effect of remarkably reducing a slip count.

[0422] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS). 14.1.4 CMT1X mouse study results

[0423] A five-month-old CMT1X mouse (Gjbl KO) was orally dosed with the compound represented by compound 5 at 10 mg / kg twice a day for six months, the motor and sensory functions were evaluated during an administration period, and the results thereof are shown in FIGS. 27 to 28. The expression and statistical processing method for the corresponding results were conducted in the same manner as the study of CX32 null mice of above 14.1.1,

[0424] For the grouping of the corresponding study, the animals were divided into each group according to the Z-array method based on the body weight of animals before drug administration, values derived from accelerating rotarod and balance beam test results as shown in table 13 below. Mice were orally dosed with the vehicle (0.5% methyl cellulose) or 10 mg / kg of compound 5 of Example 5 according to a defined group.

[0425] Male CMT1X mice used for the corresponding study were provided with a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with a temperature (22 ± 2°C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed according to the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (with an approved number: S-22_012).

[0426] [Table 15] Constant rotarod test

[0427] A constant rotarod test (ROTAROD, LE8205, Panlab) was performed to evaluate a motor coordination function / motor function. Before the test, all test animals were placed on a rod which rotate at 10 rpm three times a day for three days to train for adaptation for about three weeks, and animals which took a time of 180 seconds or more to fall off the rod were used for the test. In this experiment, the time for an animal to fall off the rod was measured for three minutes. A total of three constant rotarod tests were conducted for one day, and a maximum value among three measured values was used. The results thereof are shown in Fig. 27.

[0428] In above FIG. 27, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh(TG) means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to CMT IX mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was orally administered to an CMT1X mouse.

[0429] As a result, as shown in FIG. 27, it was confirmed that the compound of the present invention exhibits an effect of remarkably enhancing the latency to fall.

[0430] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0431] Balance beam test

[0432] A balance beam test was performed to measure a motor coordination function and a unique sense of limbs, and a research method was performed in the same manner as the CX32 null mouse study of above 14.1.1, and the results thereof are shown in FIG. 28.

[0433] In above FIG. 28 a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh(TG) means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to CMT IX mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was orally administered to a CMT1X mouse.

[0434] As shown in above FIG. 28, it was confirmed that the compound of the present invention (for example, compound 5 of Example 5) exhibits an effect of remarkably reducing a slip count.

[0435] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0436] 14.1.5 CMT1A mouse study results

[0437] A six-and half -week-old CMT1 A mouse (hPMP22 3-4 copies) was orally dosed with the compound represented by compound 5 at 10 mg / kg twice a day for six week, the motor and sensory functions were evaluated during an administration period, and the results thereof are shown in FIGS. 29 to 30. The expression and statistical processing method for the corresponding results were conducted in the same manner as the study of CX32 null mice of above 14.1.1,

[0438] For the grouping of the corresponding study, the animals were divided into each group according to the Z-array method based on the body weight of animals before drug administration, values derived from accelerating rotarod and balance beam test results as shown in table 16 below. Mice were orally dosed with the vehicle (0.5% methyl cellulose) or 10 mg / kg of compound 5 of Example 5 according to a defined group.

[0439] Male CMT1A mice used for the corresponding study were provided with a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with a temperature (22 ± 2°C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed according to the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (with an approved number: S-22_012).

[0440] [Table 16]

[0441] Constant rotarod test

[0442] A constant rotarod test (ROTAROD, LE8205, Panlab) was performed to evaluate a motor coordination function / motor function. Before the test, all test animals were placed on a rod which rotate at 10 rpm three times a day for three days to train for adaptation for about three weeks, and animals which took a time of 180 seconds or more to fall off the rod were used for the test. In this experiment, the time for an animal to fall off the rod was measured for three minutes. A total of three constant rotarod tests were conducted for one day, and a maximum value among three measured values was used. The results thereof are shown in Fig.

[0443] 29.

[0444] In above FIG. 29, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh(TG) means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to CMT1A mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was orally administered to an CMT1 A mouse.

[0445] As a result, as shown in FIG. 29, it was confirmed that the compound of the present invention (for example, compound 5 of Example 5) exhibits an effect of remarkably enhancing the latency to fall.

[0446] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0447] Balance beam test

[0448] A balance beam test was performed to measure a motor coordination function and a unique sense of limbs, and a research method was performed in the same manner as the CX32 null mouse study of above 14.1.1, and the results thereof are shown in FIG. 30.

[0449] In above FIG. 30 a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh(TG) means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to CMT1A mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was or6ally administered to a CMT1 A mouse.

[0450] As shown in above FIG. 30, it was confirmed that the compound of the present invention (for example, compound 5 of Example 5) exhibits an effect of remarkably reducing a slip count.

[0451] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0452] 14.2 Nerve conduction study (NCS)

[0453] Through this experiment, an attempt was made to evaluate the efficacy of the compound of the present invention by confirming the effect of the compound of the present invention on the nerve conduction velocity of animals.

[0454] The animals used in the nerve conduction study were the animals which were studied in section 14.1.2, and the nerve conduction study was performed after administering the compound or vehicle to male six-month-old MFN2 mutant mice for three months.

[0455] Animals were anesthetized with isoflurane (USP Terrel, Piramal Critical Care, Inc., NDC 66794-017-25) in 30% oxygen (Daehan gas) and 70% nitrogen (Daehan gas). In this state, electrophysiological recordings were evaluated by electroconduction in the tail nerves associated with sensory nerve conduction in the peripheral nervous system (PNS). The corresponding nerve conduction study (NCS) was performed using a Nicolet Viking Quest. A sensory neuron action potential (SNAP) amplitude and sensory neuron conduction velocity (SNCV) were measured. Data were expressed as mean ± SEM, and statistical significance between the group treated with the compound of the present invention and the vehicle group was analyzed with one-way ANOVA (post-hoc analysis using Dunnett's test) for comparison of three or more groups. All statistical analyses were performed with GraphPad Prism (ver 9.0) and the results thereof are shown in FIG. 31.

[0456] In above FIG. 31, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh means a CMT disease model mouse control group in which vehicle (0.5% methyl cellulose) was orally administered to MFN2 mutant mice, and compound 5 represents a group in which the compound represented by compound 5 was orally administered to an MFN2 mutant mouse.

[0457] As shown in FIG. 31, it was confirmed that the compound of the present invention exhibits an effect of remarkably improving the SNAP and SNCV, and thus was advantageously used for preventing and treating the CMT by improving a nerve conduction velocity.

[0458] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

[0459] 14.3. Histopathological analysis

[0460] Through this experiment, an attempt was made to confirm the effect of the compound of the present invention on the axon size of the sciatic nerve fiber.

[0461] 14.3.1 CX32 null mouse study results

[0462] The animals used in a histopathological analysis were the animals which were studied in section 14.1.1, and the histopathological analysis was performed after administering the compound or vehicle to male five-month-old CX32 null mice for five months.

[0463] After a final treatment with the compound 5 (10 mg / kg) of the present invention, the sciatic nerve was collected at 0.5 hours and fixed overnight in a 2.5% glutaraldehyde solution (340855, Sigma). A fixed sample was transferred to the Department of Pathology in University of Ulsan for semithin sections and toluidine blue (T3260, Sigma) staining.

[0464] A fixed sample was processed in a conventional method for image analysis (see Acta Neuropathologica Communications volume 7. Article number: 144 (2019), Sele et al.), and then a 0.5 pm section was prepared and stained with toluidine blue.

[0465] A histological evaluation was performed under optical microscopy. Pathological changes including demyelination, remyelination, abnormally thin myelin, and axonal morphological change were investigated from the section. Finally, a diameter of axons was analyzed with image J software, and the results thereof are shown in FIG. 32.

[0466] In above FIG. 32, a normal group (wild type, WT) refers to a normal mouse to which vehicle was orally administered, Veh means a CMT disease model mouse control group in which vehicle was orally administered to CX32 null mice, compound 5 represents a group in which the compound represented by compound 5 was orally administered to a CMT disease mouse (CX32 null mouse) with CX32 knocked out.

[0467] Data were expressed as mean ± SEM. Statistical significance between the group treated with the compound of the present invention and the vehicle group was analyzed with one-way ANOVA (post-hoc analysis using Dunnett' s test) for comparison of three or more groups. All statistical analyses were performed with GraphPad Prism (ver 9.0).

[0468] As shown in FIG. 32, it was confirmed that the compound of the present invention remarkably improves an increase in axon size of the sciatic nerve fiber.

[0469] Accordingly, it was confirmed that the compound of the present invention exhibits an excellent effect of preventing and treating neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot- Marie-Tooth disease such as Charcot-Marie-Tooth disease (CMT) associated with the peripheral nervous system (PNS) and Charcot-Mari e-Tooth disease (CMT) associated with the central nervous system (CNS).

Claims

CLAIMS

1. A compound represented by formula I below, stereoisomers thereof or pharmaceutically acceptable salts thereof:[Formula I]in above formula I,Xi to X4 are each independently N or CRx, in which three or more of Xi to X4 may not be N at the same time, and Rx is -H, F, Cl, Br or I;Ri is -CXaFb, -C(Xa)2H, or -C(Xa)3, in which Xa is F, Cl, Br or I; andR2 and R3 are each independently F, Cl, Br or I.

2. The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to claim 1, whereinXi to X4 are each independently N or CRx, in which three or more of Xi to X4 may not be N at the same time, and Rx is -H or F;Ri is -CXaFb or -C(Xa)2H, in which Xa is F or Cl; andR2 and R3 are each independently F or Cl.

3. The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to claim 1, wherein the compound represented by above formula l is a compound represented by formula II below:[Formula II]in above formula II,X2 is N or CRx, in which Rxis -H, F, Cl, Br or I;Ri is -CXaFb, -C(Xa)2H, or -C(Xa)3, in which Xa is F, Cl, Br or I; andR2 and R3 are each independently F, Cl, Br or I.

4. The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to claim 1 or 3, wherein the compound represented by above formula I is a compound represented by formula II- 1 , II-2, II-3, or II-4 below:[Formula II- 1][Formula II-3]in above formula II- 1, II-2, II-3, or II-4,X2 is independently N or CRx in each formula, and Rx is H, F or Cl, Br or I;Ri is independently -CXaFF -C(Xa)2H, or -C(Xa)3 in each formula, in which Xa isindependently H, F, Cl, Br or I in each formula; andR2 and R3 are each independently F, Cl, Br or I in each formula.

5. The compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to claim 4, wherein: in above formula II- 1, II-2, II-3, or II-4,X2 is independently N or CRx in each formula, in which Rxis -H or F;Ri is independently -C(Xa)2H or -C(Xa)3 in each formula, in which Xa is independentlyF or Cl in each formula; andR2 and R3 are each independently F or Cl in each formula.

6. A compound having a structure represented by formula below, stereoisomers thereof or pharmaceutically acceptable salts thereof:

7. The compound, stereoisomers thereof or pharmaceutically acceptable salts thereof according to claim 6, wherein the compound is a compound represented by formula below:

8. A pharmaceutical composition comprising the compound according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof as an effective component.

9. The pharmaceutical composition according to claim 8, wherein the pharmaceutical composition is for preventing or treating histone deacetylase 6-mediated diseases.

10. The pharmaceutical composition according to claim 9, wherein the histone deacetylase 6-mediated diseases are infectious diseases; neoplasm; endocrinopathy, nutritional and metabolic diseases; mental and behavioral disorders; neurological diseases; eye and ocular adnexal diseases; circulatory diseases; respiratory diseases; digestive troubles; skin and subcutaneous tissue diseases; musculoskeletal system and connective tissue diseases; or teratosis, deformities and chromosomal aberration.

11. The pharmaceutical composition according to claim 10, wherein: the infectious diseases are prion disease; the neoplasm is benign tumor or malignant tumor; the endocrinopathy, 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 nervous system atrophy including central nervous system atrophy, neurodegenerative disease, motor disorder, neuropathy, motor neuron disease or central nervous system demyelinating disease; the eye and ocular adnexal diseases are uveitis; the circulatory diseases are atrial fibrillation or stroke; the respiratory diseases are asthma; the digestive troubles are alcoholic liver disease, inflammatory bowel disease, Crohn's disease or ulcerative bowel disease;the skin and subcutaneous tissue diseases are psoriasis; the musculoskeletal system and connective tissue diseases are rheumatoid arthritis, osteoarthritis or systemic lupus erythematosis; and the teratosis, deformities and chromosomal aberration are autosomal dominant polycystic kidney disease.

12. The pharmaceutical composition according to claim 11, wherein: the nervous system atrophy comprising central nervous system atrophy is Huntington's disease, spinal muscular atrophy (SMA), or spinocerebellar ataxia (SCA); the neurodegenerative disease is Alzheimer's disease or tauopathy; the motor disorder is Parkinson's disease; the neuropathy disease is hereditary neuropathy comprising Charcot-Marie-Tooth disease or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, or drug-induced neuropathy; the motor neuropathy is amyotrophic lateral sclerosis (ALS); and the central nervous system demyelinating disease is multiple sclerosis (MS).

13. A pharmaceutical composition comprising the compound according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof as an effective component for preventing or treating nervous system atrophy comprising central nervous system atrophy, neurodegenerative diseases, or neuropathy.

14. The pharmaceutical composition according to claim 13, wherein: the central nervous system atrophy is Huntington's disease, spinal muscular atrophy (SMA), or spinocerebellar ataxia (SCA); the neurodegenerative disease is dementia, Alzheimer's disease or tauopathy; and the neuropathy is hereditary neuropathy comprising Charcot-Marie-Tooth disease or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, drug-induced neuropathy, amyotrophic lateral sclerosis (ALS), or multiple sclerosis (MS).

15. A method for preventing or treating histone deacetylase 6-mediated diseases, comprising administering a therapeutically effective amount of the compound according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof.

16. A use of the compound according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof for preventing or treating histone deacetylase 6- mediated diseases.

17. A use of the compound according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof for preparing a medicament for preventing ortreating histone deacetylase 6-mediated diseases.

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