Oxadiazole-derived compounds and the pharmaceutical composition comprising them.

Description

1 / 119 “OXADIAZOLE DERIVED COMPOUNDS AND THE PHARMACEUTICAL COMPOSITION COMPRISING THEM Field of the Technique

[0001] The present invention relates to novel oxadiazole derivatives, stereoisomers thereof or pharmaceutically acceptable salts thereof; a pharmaceutical composition containing oxadiazole derivatives, stereoisomers or pharmaceutically acceptable salts thereof; a use of oxadiazole derivatives, stereoisomers or pharmaceutically acceptable salts thereof in the preparation of a therapeutic drug; a method for preventing or treating diseases by administering oxadiazole derivatives, stereoisomers or pharmaceutically acceptable salts thereof; and a method for preparing oxadiazole derivatives, stereoisomers or pharmaceutically acceptable salts thereof. Background

[0002] In cells, a post-translational modification, such as acetylation, serves as a very important regulatory module at the heart of biological processes and is also strictly controlled by various enzymes. As a core protein that constitutes chromatin, histone functions as a spindle around which DNA wraps, thus aiding in DNA condensation. Furthermore, the balance between histone acetylation and deacetylation plays a very important role in gene expression.

[0003] As an enzyme to remove an acetyl group from the lysine residue of the histone protein, which constitutes chromatin, histone deacetylase (HDAC) is Petition 870250092262, dated 09 / 10 / 2025, page 5 / 147 2 / 119 is known to be associated with gene silencing and inducing cell cycle arrest, angiogenic inhibition, immunoregulation, apoptosis, etc. (Hassig et al., Curr. Opin. Chem. Biol. 1997, 1, 300-308). Furthermore, it is reported that inhibition of HDAC enzyme functions induces cancer cells to undergo apoptosis on their own, reducing the activity of factors related to cancer cell survival and activating factors related to cancer cell death in the body (Warrell et al., J. Natl. Cancer Inst. 1998, 90, 1621-1625).

[0004] For humans, 18 HDACs are known and classified into four classes, according to their homology with yeast HDACs. In this case, eleven HDACs that use zinc as a cofactor can be divided into three groups: Class I (HDAC1, 2, 3, 8), Class II (IIa: HDAC4, 5, 7, 9; IIb: HDAC6, 10) and Class IV (HDAC11). In addition, seven Class III HDACs (SIRT 1-7) use NAD+ as a cofactor instead of zinc (Bolden et al., Nat. Rev. Drug Discov. 2006, 5(9), 769-784).

[0005] Several HDAC inhibitors are currently in preclinical or clinical development, but only non-selective HDAC inhibitors are known as anticancer agents to date. Vorinostat (SAHA) and romidepsin (FK228) have been approved as therapeutic agents for cutaneous T-cell lymphoma, while panobinostat (LBH-589) has been approved as a therapeutic agent for multiple myeloma. However, it is known that non-selective HDAC inhibitors often cause side effects such as fatigue, nausea, and similar symptoms at high doses (Piekarz et al., Pharmaceuticals 2010, 3, 2751-2767). It Petition 870250092262, dated 09 / 10 / 2025, page 6 / 147 3 / 119 reported that side effects are caused by the inhibition of class I HDACs. Due to side effects, etc., non-selective HDAC inhibitors have been subject to restrictions in drug development in areas other than anticancer agents (Witt et al., Cancer Letters 277, (2009), 8-21).

[0006] Meanwhile, it is reported that selective inhibition of class II HDACs would not present toxicity, which occurred in the inhibition of class I HDACs. The development of selective HDAC inhibitors would likely resolve the side effects, such as toxicity, etc., caused by non-selective inhibition of HDACs. Consequently, there is a possibility that selective HDAC inhibitors could be developed as an effective therapeutic agent for various diseases (Matthias et al., Mol. Cell. Biol. 2008, 28, 1688-1701).

[0007] It is known that HDAC6, one of the class IIb HDACs, is mainly present in the cytoplasm and contains a tubulin protein, and is therefore involved in the deacetylation of several non-histone substrates (HSP90, cortactin, etc.) (Yao et al., Mol. Cell 2005, 18, 601-607). HDAC6 has two catalytic domains, in which a C-terminal zinc finger domain can bind to a ubiquitinated protein. It is known that HDAC6 has several non-histone proteins as substrates and therefore plays an important role in various diseases, such as cancer, inflammatory diseases, autoimmune diseases, neurological diseases, neurodegenerative disorders and the like (Santo et al., Blood 2012 119, 2579-2589; Vishwakarma et al., International Immunopharmacology 2013, 16, 72-78; Hu et al., J. Neu-rol. Petition 870250092262, dated 09 / 10 / 2025, page 7 / 147 4 / 119 (Sci. 2011, 304, 1-8).

[0008] A common structural feature of several HDAC inhibitors is their composition of a cap group, a linker group, and a zinc-binding group (ZBG), as shown in the vorinostat structure below. Many researchers have conducted a study on the inhibitory activity and selectivity towards enzymes through a structural modification of the cap group and the linker group. Of the groups, the zinc-binding group is known to play a more important role in the inhibitory activity and selectivity of the enzyme (Wiest et al., J. Org. Chem. 2013 78: 5051-5055; Metot et al., Bioorg. Med. Chem. Lett. 2008, 18, 973-978). Cap group, zinc bonding group (ZBD).

[0009] Most of the aforementioned zinc-binding group is composed of hydroxamic acid or benzamide, of which hydroxamic acid derivatives exhibit a strong inhibitory effect on HDAC, but present a problem of low bioavailability and serious off-target activity. Benzamide contains aniline and therefore presents a problem as it can produce toxic metabolites in vivo (Woster et al., Med. Chem. Commun. 2015, online publication).

[0010] Consequently, unlike non-selective inhibitors that have side effects, there is a need to develop a selective inhibitor of Petition 870250092262, dated 09 / 10 / 2025, p. 8 / 147 5 / 119 HDAC6, which has a zinc-binding group with enhanced bioavailability, without causing side effects, is used to treat cancer, inflammatory diseases, autoimmune diseases, neurological diseases, neurodegenerative disorders, and similar conditions. Reference to Related Technique [Patent Documents] (Patent Document 1) Patent Publication International Unexamined Patent No. WO 2011 / 091213 (Patent Document 2) Patent Publication International Unexamined Patent No. WO 2011 / 011186 (Patent Document 3) Patent Publication International Unexamined Patent No. WO 2013 / 052110 (Patent Document 4) Patent Publication International Unexamined Patent No. WO 2013 / 041407 (Patent Document 5) Patent Publication International Unexamined Patent No. WO 2013 / 134467 (Patent Document 6) Patent Publication International Unexamined Patent No. WO 2013 / 008162 (Patent Document 7) Patent Publication International Unexamined Publication No. WO 2013 / 080120 (Patent Document 8) International Unexamined Publication Patent Publication No. WO 2013 / 066835 (Patent Document 9) International Unexamined Patent Publication No. WO 2013 / 066838 (Patent Document 10) Patent Publication International Unexamined Patent No. WO 2013 / 066833 (Patent Document 11) Patent Publication International Unexamined No. WO 2013 / 066839 Petition 870250092262, dated 09 / 10 / 2025, page 9 / 147 6 / 119 Detailed Description of the Invention Technical Problem

[0011] An object of the present invention is to provide oxadiazole-derived compounds with selective inhibitory activity against HDAC6, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0012] Another objective of the present invention is to provide a pharmaceutical composition including oxadiazole-derived compounds with selective HDAC6 inhibitory activity, their stereoisomers or pharmaceutically acceptable salts.

[0013] Another objective of the present invention is to provide a method for preparing oxadiazole-derived compounds, their stereoisomers, or pharmaceutically acceptable salts.

[0014] Another objective of the present invention is to provide a pharmaceutical composition for preventing or treating diseases related to HDAC6 activity or degenerative brain diseases, including oxadiazole derivatives, stereoisomers thereof, or pharmaceutically acceptable salts thereof.

[0015] Another objective of the present invention is to provide a use of oxadiazole-derived compounds, their stereoisomers or pharmaceutically acceptable salts in the preparation of a medicament to prevent or treat diseases related to HDAC6 activity or degenerative brain diseases.

[0016] Another objective of the present invention is to provide a method for preventing or treating diseases related to HDAC6 activity or brain diseases. Petition 870250092262, dated 09 / 10 / 2025, page 10 / 147 7 / 119 degenerative, including the administration of a therapeutically effective amount of oxadiazole derivatives, their stereoisomers, or pharmaceutically acceptable salts thereof.

[0017] Another objective of the present invention is to provide a use of oxadiazole-derived compounds, their stereoisomers, or pharmaceutically acceptable salts in the prevention or treatment of diseases related to HDAC6 activity or degenerative brain diseases. Technical Solution

[0018] The present inventors have found an oxadiazole-derived compound with histone deacetylase 6 (HDAC6) inhibitory activity and have used it to inhibit or treat diseases related to HDAC6 activity, thus completing the present invention.

[0019] The present invention will now be described in more detail. All combinations of various elements disclosed in the present invention fall within the scope of the present invention. Furthermore, it cannot be concluded that the scope of the present invention is limited to the specific description below. Compound

[0020] The present invention can provide a compound according to any of items (1) to (7) below, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0021] (1) A compound represented by the formula Below are the stereoisomers of the same or the pharmaceutically acceptable salts thereof: Petition 870250092262, dated 09 / 10 / 2025, p. 11 / 147 8 / 119 Formula 1 In Formula 1 above, Xi to X4 are each independently N or CRX, where 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 -CXaH2, -C(Xa)2H, or -C(Xa)3, where Xa is F, Cl, Br, or I; and R2e Rs are each independently F, Cl, Br, or I.

[0022] (2) The compound represented by the Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to (1) above: In Formula 1 above, Xi to X4 are each independently N or -CRX, where three or more of Xi to X4 may not be N at the same time, and Rx is H or F; Ri is -CXaH2or -C(Xa)2H, where Xa is F or Cl; and R2 and R3 can each be independently F or Cl.

[0023] (3) The compound represented by the Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to (1) or (2) above: The compound represented by Formula I above can be a compound represented by Formula II: Petition 870250092262, dated 09 / 10 / 2025, p. 12 / 147 9 / 119 Formula II In Formula II above, X2 is N or CRX, where Rx is H, F, Cl, Br, or I; Ri is -CXaH2, -C(Xa)2H, or -C(Xa)3, where Xa is F, Cl, Br, or I; and R2 and R3 can each independently be F, Cl, Br, or I.

[0024] (4) The compound represented by the Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to (1), (2) or (3) above: The compound represented by Formula I or II above may be a compound represented by Formula II-1, II-2, II-3, or II-4 below. Formula II-l Formula II-2 Petition 870250092262, dated 09 / 10 / 2025, p. 13 / 147 10 / 119

[0025] In Formula II-1, II-2, II-3, or II-4 above, X2 is independently N or CRX in each formula, and Rx is H, F or Cl, Br or I; Ri is independently -CXaH2, -C(Xa)2H, or -C(Xa)3 in each formula, where Xa is independently F, Cl, Br, or I in each formula; and R2 and R3 are each independently F, Cl, Br, or I in each formula.

[0026] (5) The compound represented by the Formula I, the stereoisomers of the same or the pharmaceutically produced salts Petition 870250092262, dated 09 / 10 / 2025, p. 14 / 147 11 / 119 acceptable of the same according to (1) above, (2), (3) or (4): In Formula II-1, II-2, II-3, or II-4 and above, X2 is independently N or -CRx in each Formula, where Rx is H or F; R1 is independently -C(Xa)2H or -C(Xa)3 in each formula, where Xa is F or Cl; and R2 and R3 are each independently F or Cl in each formula.

[0027] In embodiments of the present invention, in Formula II-1, II-2, II-3, or II-4 above, R2 and R3 may be the same or different from each other.

[0028] In embodiments of the present invention, in Formula I above, II, or I-1, R2 and R3 may be the same 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.

[0029] In embodiments of the present invention, in Formula I, II, II-2, II-3, or II-4 above, R2 and R3 may be the same or different from each other, and specifically, R2 and R3 may be the same with respect to each other. For example, both R2 and R3 may be F, or they may be Cl.

[0030] (6) The compound represented by Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to (1), (2), (3), (4) or (5) above: 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. Petition 870250092262, dated 09 / 10 / 2025, p. 15 / 147 12 / 119 Table 1 Compound (Name) Structure Compound (Name) Structure Compound 1 Fx^^x N-nz oY Compound 2 FYY ΐ YY Λ° ^ryCF2H N-nz oY Compound 3 Fxz^ d N zx, N Y'Y0 Υ\Ο^εΡ2Η NN oY Compound 4 Cl CIY I fn γγ Ύ N-Nz oY Compound 5 !< ob z=\ ^Ύ° o NI Compound 6 Ύ Y 1 jOtx 0 ^Y°^CF2H N'N oY Compound 7 ΓΥ01 JL Cl JCO n YY ° / >cf2h Nn oY Compound 8 t! , ob oy O ο rsj I

[0031] (7) The compound represented by Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to (1) above, (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 Table 1 above.

[0032] In the present invention, the term “pharmaceutically acceptable” may refer to that which is Petition 870250092262, dated 09 / 10 / 2025, p. 16 / 147 13 / 119 is physiologically acceptable and does not conventionally cause an allergic response, such as gastrointestinal disturbances and dizziness, or other similar responses, when administered to an individual.

[0033] The pharmaceutically acceptable salt of the present invention can be prepared by a conventional method known to those skilled in the art.

[0034] In the present invention, pharmaceutically acceptable salts may refer to 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, ascorbic 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 similar substances; amino acid salts prepared from glycine, arginine, lysine, etc.; amine salts prepared from trimethylamine, triethylamine, ammonia, pyridine, picoline, etc.; and similar substances, but the same types. Petition 870250092262, dated 09 / 10 / 2025, page 17 / 147 14 / 119 of the salts mentioned in the present invention are not limited to the salts listed.

[0035] In the present invention, preferred salts may include hydrochloric acid, trifluoroacetic acid, citric acid, bromic acid, maleic acid, phosphoric acid, sulfuric acid, tartaric acid, etc.

[0036] 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, therefore, may be present as a racemate, racemic mixture, single enantiomer (optical isomer), mixture of diastereomers and respective diastereomers thereof.

[0037] 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, HPLC splitting or similar. Alternatively, each stereoisomer of the compound represented by formula I, II, II-1, II-2, II-3 or II-4 may be synthesized stereospecifically with a known arrangement of optically pure starting materials and / or reagents.

[0038] In the present invention, a stereoisomer may include a diastereomer and an optical isomer (enantiomer), wherein the optical isomer may include not only an enantiomer, but also a mixture of the enantiomer and even a racemate.

[0039] The compound represented by formulas 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 Petition 870250092262, dated 09 / 10 / 2025, page 18 / 147 15 / 119 The present invention may exhibit histone deacetylase 6 (HDAC6) inhibitory activity, specifically selective inhibitory activity against HDAC6 and, more specifically, very high selective inhibitory activity against HDAC6 compared to other HDAC isotypes, and exhibit very high inhibitory activity against HDAC6 but little or no inhibitory activity against other HDAC isotypes (Tables 3, 4 and 5).

[0040] The compound represented by formulas 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, can noticeably increase tubulin acetylation in nerve cells (Figures 4 and 5).

[0041] The compound represented by formulas 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 exhibit activity in preventing or treating diseases related to histone deacetylase 6 (HDAC6) activity or drug-related diseases.

[0042] In the present invention, prevention may refer to all acts that inhibit or delay the occurrence of a disease by administering the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in table 1, the stereoisomers thereof or the pharmaceutically acceptable salts thereof according to the present invention.

[0043] In the present invention, treatment may refer to all acts by which a suspected symptom of Petition 870250092262, dated 09 / 10 / 2025, p. 19 / 147 16 / 119 an individual likely to develop a disease or a symptom of an individual suffering from a disease improves or takes a favorable course by administration of the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in table 1, the stereoisomers thereof or the pharmaceutically acceptable salts thereof according to the present invention.

[0044] In the present specification, histone deacetylase-mediated disease may refer to a disease associated with histone deacetylase 6 (HDAC6) activity.

[0045] In embodiments of the present invention, diseases related to histone deacetylase 6 (HDAC6) activity or histone deacetylase 6-mediated diseases may include infectious diseases, neoplasms, endocrinopathies, nutritional and metabolic diseases, mental and behavioral disorders, neurological diseases, ocular and ocular adnexal diseases, circulatory diseases, respiratory diseases, digestive problems, skin and subcutaneous tissue diseases, musculoskeletal and connective tissue diseases, or teratosis, deformities and chromosomal aberrations, etc.

[0046] In embodiments of the present invention, infectious diseases may be prion disease; neoplasia may be benign or malignant tumor; endocrinopathy, nutritional and metabolic diseases may be Wilson's disease, amyloidosis or diabetes; mental and behavioral disorders may be depression or Rett syndrome; neurological diseases may be atrophy of the nervous system, including central nervous system atrophy, neurodegenerative disease, motor disorder, neuropathy, disease of Petition 870250092262, dated 09 / 10 / 2025, page 20 / 147 17 / 119 motor neuron or demyelinating disease of the central nervous system; eye and ocular adnexal diseases may be uveitis; circulatory diseases may be atrial fibrillation or stroke; respiratory diseases may be asthma; digestive problems may be alcoholic liver disease, inflammatory bowel disease, Crohn's disease, or ulcerative bowel disease; skin and subcutaneous tissue diseases may be psoriasis; musculoskeletal and connective tissue diseases may be rheumatoid arthritis, osteoarthritis, or systemic lupus erythematosus; and teratosis, deformities, and chromosomal aberrations may be autosomal dominant polycystic kidney disease.

[0047] In embodiments of the present invention, nervous system atrophy, including central nervous system atrophy, may be Huntington's disease, spinal muscular atrophy (SMA), or spinocerebellar ataxia (SCAA); neurodegenerative disease may be Alzheimer's disease or tauopathy; motor disorder may be Parkinson's disease; neuropathic disease may be hereditary neuropathy, including Charcot-Marie-Tooth disease (peripheral Charcot-Marie-Tooth neuropathic disease, central Charcot-Marie-Tooth neuropathic disease) or hereditary spastic paraplegia, diabetic neuropathy, sporadic neuropathy, inflammatory neuropathy, or drug-induced neuropathy; motor neuropathy may be amyotrophic lateral sclerosis (ALS); and demyelinating disease of the central nervous system may be multiple sclerosis (MS).

[0048] In embodiments of the present invention, diseases related to histone deacetylase 6 activity Petition 870250092262, dated 09 / 10 / 2025, p. 21 / 147 18 / 119 (HDAC6) or histone deacetylase 6-mediated diseases may include cancer, inflammatory diseases, autoimmune diseases, neurological or neurodegenerative diseases, specifically, lung cancer, colon cancer, breast cancer, prostate cancer, liver cancer, brain cancer, ovarian cancer, gastric cancer, skin cancer, pancreatic cancer, 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 Charcot-Marie-Tooth neuropathic disease, central Charcot-Marie-Tooth neuropathic 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 histone deacetylase 6 function.

[0049] The compound represented by formulas 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 exhibit high permeability to the cerebrovascular barrier. Specifically, the compound represented by formulas 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, Petition 870250092262, dated 09 / 10 / 2025, p. 22 / 147 19 / 119 may exhibit a high B / P ratio after oral administration (Table 10).

[0050] The compound represented by formulas 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 exhibit an excellent preventive and therapeutic effect on atrophy of the nervous system, including atrophy of the central nervous system, neurodegenerative diseases, including degenerative brain diseases, hereditary neuropathy or the like.

[0051] In embodiments of the present invention, nervous system atrophy, including central nervous system atrophy, neurodegenerative diseases or hereditary neuropathy, may be Huntington's disease, spinal muscular atrophy (SMA), spinocerebellar ataxia (SCAA), 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).

[0052] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in Table 1, stereoisomers, isomers thereof or pharmaceutically acceptable salts thereof, may exhibit a remarkably excellent preventive and therapeutic effect in Petition 870250092262, dated 09 / 10 / 2025, p. 23 / 147 20 / 119 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.

[0053] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in Table 1, stereoisomers and isomers thereof or pharmaceutically acceptable salts thereof, can increase the relative velocity of mitochondrial axons, which is reduced by treatment with β-amyloid protein fragment (Αβ), and this pharmacological effect can last for a long period of time. Consequently, the compounds of the present invention can 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, Figures 1 and 2).

[0054] In embodiments of the present invention, the compound represented by formulas 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, can increase the relative velocity of mitochondrial axons, which is reduced in nerve cells in which the tau protein is overexpressed. Consequently, the compounds of the present invention can exhibit Petition 870250092262, dated 09 / 10 / 2025, page 24 / 147 21 / 119 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 Figure 3).

[0055] In embodiments of the present invention, the compound represented by formulas 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, can noticeably improve cognitive decline in taupathic mice (PS19 mice). Consequently, the compounds of the present invention can 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).

[0056] In embodiments of the present invention, the compound represented by formulas 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 can notably reduce tau hyperphosphorylation observed in the brains of tauopathic mice (PS19 mice). Consequently, the compounds of the present invention can 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).

[0057] In embodiments of the present invention, the Petition 870250092262, dated 09 / 10 / 2025, p. 25 / 147 The compounds represented by formulas I, II, II-1, II-2, II-3, or II-4, compounds 1 to 8 described in Table 1, stereoisomers, isomers thereof, or pharmaceutically acceptable versions thereof, can significantly enhance impaired long-term hippocampal memory in tauopathic mice (PS19 mice). Consequently, 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 (Figures 14 and 15).

[0058] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in Table 1, stereoisomers thereof or pharmaceutically acceptable versions thereof can noticeably improve ataxia symptoms in Huntington's disease model mice (Yac128 mice) and can noticeably increase reduced grip strength in Huntington's disease model mice (Yac128 mice). Consequently, the compounds of the present invention can 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).

[0059] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in Table 1, stereoisomers thereof or pharmaceutically Petition 870250092262, dated 09 / 10 / 2025, p. 26 / 147 23 / 119 acceptable levels of them can notably increase the relative velocity of mitochondria in the root ganglia of Charcot-Marie-Tooth disease (CMT) model mice (MFN2 mutant mice). Consequently, 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 Figure 20).

[0060] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in Table 1, stereoisomers thereof or pharmaceutically acceptable versions thereof can noticeably improve the reduced drop delay time in the null murine CX32 model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a constant speed rotarod test) and can noticeably reduce the slip count and transverse time of a rod, which were increased in the null murine CX32 model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a balance beam test). Consequently, the compounds of the present invention may exhibit excellent preventive and therapeutic effects in neuronal system atrophy, such as central nervous system atrophy, including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (FIGS. 21 and 22).

[0061] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II Petition 870250092262, dated 09 / 10 / 2025, p. 27 / 147 24 / 119 or II-4, compounds 1 to 8 described in Table 1, stereoisomers thereof, or pharmaceutically acceptable versions thereof can notably improve the reduced drop delay time in the MFN2 mutant murine model of Charcot-Marie-Tooth disease (CMT) (as confirmed by an acceleration rotarod test) and can notably reduce the increased slip count in the MFN2 mutant murine model of Charcot-Marie-Tooth disease (CMT) (as confirmed by a balance beam test). Consequently, the compounds of the present invention can 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).

[0062] In embodiments of the present invention, the compound represented by formulas I, II, II-1, II-2, II-3 or II-4, compounds 1 to 8 described in Table 1, stereoisomers thereof or pharmaceutically acceptable versions thereof can noticeably improve the reduced drop delay time in the CMT2A murine model of Charcot-Marie-Tooth (CMT) disease (as confirmed by an acceleration rotarod test) and can noticeably reduce the increased slip count in the CMT2A murine model of Charcot-Marie-Tooth (CMT) disease (as confirmed by a balance beam test). Consequently, the compounds of the present invention can exhibit excellent preventive and therapeutic effects on neuronal system atrophy, such as central nervous system atrophy, including Charcot-Marie-Tooth disease, diseases Petition 870250092262, dated 09 / 10 / 2025, p. 28 / 147 25 / 119 neurodegenerative or hereditary neuropathy (Figures 25 and 26).

[0063] In embodiments of the present invention, the compound represented by formulas 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 can noticeably improve the reduced drop delay time in the CMT1X murine model of Charcot-Marie-Tooth (CMT) disease (as confirmed by a constant rotarod test) and can noticeably reduce the slip count that was increased in the CMT1X murine model of Charcot-Marie-Tooth (CMT) disease (as confirmed by a balance beam test). Consequently, the compounds of the present invention may exhibit excellent preventive and therapeutic effects in neuronal system atrophy, such as central nervous system atrophy, including Charcot-Marie-Tooth disease, neurodegenerative diseases, or hereditary neuropathy (Figures 27 and 28).

[0064] In embodiments of the present invention, the compound represented by formulas 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 can noticeably improve the reduced drop delay time in the CMT1A murine model of Charcot-Marie-Tooth (CMT) disease (as confirmed by a constant rotarod test) and can noticeably reduce the slip count that was increased in the CMT1A murine model of Charcot-Marie-Tooth (CMT) disease (as confirmed by a balance beam test). Consequently, the Petition 870250092262, dated 09 / 10 / 2025, p. 29 / 147 26 / 119 compounds of the present invention may exhibit excellent preventive and therapeutic effects in neuronal system atrophy, such as central nervous system atrophy, including Charcot-Marie-Tooth disease, neurodegenerative diseases or hereditary neuropathy (Figures 29 and 30).

[0065] In embodiments of the present invention, the compound represented by formulas 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 can noticeably improve the sensory neuron action potential amplitude (SNAP) and sensory neuron conduction velocity (SNCV), which were reduced in the MFN2 mutant murine model of Charcot-Marie-Tooth disease (CMT). Consequently, the compounds of the present invention can 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 (Figure 31).

[0066] In embodiments of the present invention, the compound represented by formulas 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 can noticeably increase the axon size of sciatic nerve fibers, which was reduced in the CX32 null murine model of Charcot-Marie-Tooth disease (CMT). Consequently, the compounds of the present invention can exhibit excellent preventive and therapeutic effects on neuronal system atrophy, such as central nervous system atrophy, including Charcot disease. Petition 870250092262, dated 09 / 10 / 2025, p. 30 / 147 27 / 119 Marie-Tooth syndrome, neurodegenerative diseases, or hereditary neuropathy (Figure 32). Method for preparing the compound

[0067] The present invention may provide a method for preparing an oxadiazole derivative compound represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0068] From now on, in the reaction formulas, the same symbols as those in formula I and not specifically described are the same as those defined in formula I, and the overlapping description is omitted. Furthermore, in the reaction formulas, PG may represent an amine protecting group and may be, for example, tert-Butyloxycarbonyl (Boc).

[0069] A preferred method for preparing an oxadiazole derivative compound represented by formula I above, 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 modified preparation method at a level evident to those skilled in the art may also be included therein.

[0070] In embodiments of the present invention, the preferred method for preparing the oxadiazole derivative compound represented by formula I above, stereoisomers thereof or pharmaceutically acceptable salts thereof can be carried out by a preparation method of reaction formula 1-1 below. Petition 870250092262, dated 09 / 10 / 2025, p. 31 / 147 28 / 119 Reaction Formula 1-1 1-1-1 1-1-2 1-1-3 1-1-4 1-1-8 1-1-9 1-1-10

[0071] In Reaction Formula 1-1 above, Xi to X4, R1, R2, and R3 can be the same as defined in Formula I, PG can be a protecting group, halo can be F, Cl, Br, or I, and alkyl can be C1 to C5 alkyl.

[0072] In embodiments of the present invention, in Petition 870250092262, dated 09 / 10 / 2025, p. 32 / 147 29 / 119 In reaction formula 1-1 above, Xi, X3, and X4 can be CH, X2 can be N, R2 and R3 can each independently be F or Cl, R1 can be CF2H, PG can be tert-butyl carboxylate, and alkyl can be methyl, ethyl, or butyl.

[0073] In the Reaction Formula 1-1 above, a compound represented by 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 above can each independently be in the form of a salt, and the salt can be hydrochloride or trifluoroacetate.

[0074] Reaction Formula 1-1 above may show a method for synthesizing a 1,3,4-oxadiazole derivative compound, wherein 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 therein, in order to prepare the compound of Formula 1-1-3 including a urea structure.

[0075] Subsequently, the resulting compound can 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 can be removed to prepare the compound of Formula 1-1-6.

[0076] The compound of Formula 1-1-6 can 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. Subsequently, trifluoroacetic anhydride and imidazole can be used to prepare the compound of Formula 1-1-10.

[0077] In embodiments of the present invention, in Reaction Formula [Reaction Formula 1-1], the compound of Petition 870250092262, dated 09 / 10 / 2025, p. 33 / 147 30 / 119 The formula 1-1-10 above could be compound 3.

[0078] In embodiments of the present invention, the preferred method for preparing the oxadiazole derivative compound represented by Formula I above, the stereoisomers thereof or the pharmaceutically acceptable salts thereof can be carried out by a preparation method of Reaction Formula 1-2 below. Reaction Formula 1-2 1-1-8 1-1-10

[0079] In Reaction Formula 1-2 above, Xi to X4, R1, R2, and R3 can be the same as defined in Formula I, PG can be a protecting group, halo can be F, Cl, Br, or I, and alkyl can be C1 to C5 alkyl.

[0080] In embodiments of the present invention, in Reaction Formula 1-2 above, X1, X3 and X4 may be CH, X2 may Petition 870250092262, dated 09 / 10 / 2025, p. 34 / 147 31 / 119 be N or -CRx (Rx can be F or Cl, Br or I), R2 and R3 can each independently be F or Cl, Ri can be CF2H, PG can be tert-butyl carboxylate, and alkyl can be methyl, ethyl, or butyl.

[0081] In Reaction Formula 1-2 above, a compound represented by 1-1-1, 1-2-1, 1-2-2, 1-1-4, 1-1-8, 1-1-9 or 1-1-10 above can each independently be in the form of a salt, and the salt can be hydrochloride or trifluoroacetate.

[0082] Reaction Formula 1-2 above may show a method for synthesizing a 1,3,4-oxadiazole compound having an oxethane structure, wherein the compound of Formula 1-1-1 including isocyanate may be reacted with the compound of Formula 1-2-1 having an oxethane introduced into it, in order to prepare the compound of Formula 1-2-2 including a urea structure.

[0083] The compound of Formula 1-2-2 can be subjected to a substitution reaction with the compound of Formula 1-1-4 to prepare compound 1-1-8, and then reacted with hydrazine to prepare compound of Formula 1-1-9 which is a hydrazide compound. Subsequently, trifluoroacetic anhydride and imidazole can be used to prepare the target compound of Formula 1-1-10.

[0084] In embodiments of the present invention, in Reaction Formula 1-2 above, the compound of Formula 1-1-10 above may be compound 4, compound 5, compound 6, compound 7, compound 8, or similar.

[0085] In embodiments of the present invention, the preferred method for preparing the oxadiazole derivative compound represented by Formula I above, its stereoisomers or pharmaceutically available salts Petition 870250092262, dated 09 / 10 / 2025, p. 35 / 147 32 / 119 acceptable amounts of the same can be achieved by a preparation method of Reaction Formula 1-3 below. Reaction Formula 1-3 1-1-5 1-1-6 1-1-8 1-1-9 1-1-10

[0086] In Reaction Formula 1-3 above, Xi to X4, R1, R2, and R3 can be the same as defined in Formula I, PG can be a protecting group, halo can be F, Cl, Br, or I, and alkyl can be C1 to C5 alkyl.

[0087] In embodiments of the present invention, in Reaction Formula 1-3 above, X1, 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 each independently be F or Cl, Ri may be CF2H, PG may be tert-butyl carboxylate, and alkyl may be methyl, ethyl or butyl.

[0088] In Reaction Formula 1-3 above, a compound Petition 870250092262, dated 09 / 10 / 2025, p. 36 / 147 33 / 119 represented by 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 above can each be independently in the form of a salt, and the salt can be hydrochloride or trifluoroacetate.

[0089] Reaction Formula 1-3 above may show a method for synthesizing an oxadiazole compound having an oxethane structure, wherein 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 therein, so as to prepare the compound of Formula 1-1-5 including a urea structure. Subsequently, the protecting group of Formula 1-1-5 may be removed to prepare the compound of Formula 1-1-6.

[0090] The compound of Formula 1-1-6 can 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. Subsequently, trifluoroacetic anhydride and imidazole can be used to prepare the target compound of Formula 1-1-10.

[0091] In embodiments of the present invention, in Reaction Formula 1-3 above, the compound of Formula 1-1-10 above may be compound 1, compound 2, or similar. Pharmaceutical composition, method of treatment using it, and use of it.

[0092] The present invention can provide a pharmaceutical composition including a compound represented by Formula I above, stereoisomers thereof or salts Petition 870250092262, dated 09 / 10 / 2025, p. 37 / 147 34 / 119 pharmaceutically acceptable of the same.

[0093] According to embodiments of the present invention, the compound represented by Formula I included in the pharmaceutical composition may be a compound represented by Formula II above.

[0094] According to embodiments of the present invention, the compound represented by Formula I included in the pharmaceutical composition may be a compound represented by Formula II-1, II-2, II-3, or II-4 above.

[0095] The present invention can provide a pharmaceutical composition including a compound of at least one of compounds 1 to 8 described in Table 1 above, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0096] The present invention can provide a pharmaceutical composition including a compound of at least one of compounds 1 and 5 described in Table 1 above, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[0097] The present invention may provide a pharmaceutical composition for preventing or treating histone deacetylase-mediated diseases including a compound represented by Formula I above, 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.

[0098] The present invention may provide a pharmaceutical composition for preventing or treating histone deacetylase 6-mediated diseases including a compound Petition 870250092262, dated 09 / 10 / 2025, p. 38 / 147 35 / 119 represented by Formula I above, 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.

[0099] The pharmaceutical composition of the present invention may exhibit the same type of pharmacological effect as the pharmacological effect exhibited by a compound represented by Formula I above, 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.

[00100] In the pharmaceutical composition, histone deacetylase 6-mediated diseases may be substantially the same as the histone deacetylase 6-mediated diseases previously examined in the compound.

[00101] In embodiments of the present invention, diseases related to or mediated by histone deacetylase 6 (HDAC6) activity may include infectious diseases, neoplasms, endocrinopathies, nutritional and metabolic diseases, mental and behavioral disorders, neurological diseases, eye and ocular adnexa diseases, circulatory diseases, respiratory diseases, digestive problems, skin and subcutaneous tissue diseases, musculoskeletal and connective tissue diseases, or teratoses, deformities and chromosomal aberrations, etc.

[00102] In embodiments of the present invention, infectious diseases may be prion disease; neoplasia may be benign or malignant tumor; endocrinopathy, nutritional and metabolic diseases may be diseases of Petition 870250092262, dated 09 / 10 / 2025, page 39 / 147 36 / 119 Wilson's disease, amyloidosis, or diabetes; mental and behavioral disorders may include depression or Rett syndrome; neurological diseases may include atrophy of the nervous system, including central nervous system atrophy, neurodegenerative disease, motor disorder, neuropathy, motor neuron disease, or demyelinating disease of the central nervous system; eye and ocular adnexa diseases may include uveitis; circulatory diseases may include atrial fibrillation or stroke; respiratory diseases may include asthma; digestive problems may include alcoholic liver disease, inflammatory bowel disease, Crohn's disease, or ulcerative bowel disease; skin and subcutaneous tissue diseases may include psoriasis; musculoskeletal and connective tissue diseases may include rheumatoid arthritis, osteoarthritis, or systemic lupus erythematosus; and teratosis, deformities, and chromosomal aberrations may include autosomal dominant polycystic kidney disease.

[00103] In embodiments of the present invention, nervous system atrophy, including central nervous system atrophy, may be Huntington's disease, spinal muscular atrophy (SMA), or spinocerebellar ataxia (SCAA); neurodegenerative disease may be Alzheimer's disease or tauopathy; motor disorder may be Parkinson's disease; neuropathy 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; Petition 870250092262, dated 09 / 10 / 2025, page 40 / 147 37 / 119 Motor neuropathy may be amyotrophic lateral sclerosis (ALS); and demyelinating disease of the central nervous system may be multiple sclerosis (MS).

[00104] In embodiments of the present invention, diseases related to or mediated by histone deacetylase 6 (HDAC6) activity may include cancer, inflammatory diseases, autoimmune diseases, neurological or neurodegenerative diseases, specifically, lung cancer, colon cancer, breast cancer, prostate cancer, liver cancer, brain cancer, ovarian cancer, gastric cancer, skin cancer, pancreatic cancer, 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, as well as symptoms or diseases related to abnormal histone deacetylase 6 function.

[00105] The present invention may provide a pharmaceutical composition for preventing or treating atrophy of the nervous system, including atrophy of the central nervous system, etc., neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy, including a compound represented by formulas I, II, III. [Illegible text - likely OCR error] 38 / 119 1, II-2, II-3 or II-4 above, 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.

[00106] In pharmaceutical composition, nervous system atrophy, neurodegenerative diseases and hereditary neuropathy may be substantially the same as the previously examined degenerative brain disease in the compound.

[00107] In embodiments of the present invention, degenerative brain diseases may be Huntington's disease, spinal muscular atrophy (SMA), spinocerebellar ataxia (SCAA), 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.

[00108] In the pharmaceutical composition, the stereoisomer and the pharmaceutically acceptable salt may be the same as those described in the compound.

[00109] The pharmaceutical composition of the present invention may also include at least one pharmaceutically acceptable additive, in addition to the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, the compound of at least one of compounds 1 to 8 described in Petition 870250092262, dated 09 / 10 / 2025, page 42 / 147 39 / 119 Table 1 lists the stereoisomers thereof or the pharmaceutically acceptable salts thereof.

[00110] In embodiments of the present invention, the pharmaceutically acceptable additives used may include saline solution, sterile water, Ringer's solution, buffered saline solution, dextrose solution, maltodextrin solution, glycerol, ethanol, and a mixture of one or more of these ingredients, and may include the addition of other conventional additives such as antioxidant, buffer solution, bacteriostatic agent, etc., if necessary. Furthermore, diluent, dispersing agent, surfactant, binder, and lubricant may be added to formulate injectable formulations such as aqueous solution, suspension, emulsion, etc., pill, capsule, granule, or tablet. Thus, the composition of the present invention may be an adhesive, liquid medicament, pill, capsule, granule, tablet, suppository, etc.The preparations can be prepared according to a conventional method used for formulation in the technique or a method disclosed in Remington's Pharmaceutical Science (latest edition), Mack Publishing Company, Easton, PA, and the composition can be formulated in various preparations depending on each disease or ingredient.

[00111] In embodiments of the present invention, the pharmaceutically acceptable additives that may be included in pharmaceutical compositions may be those conventionally used in the art, including specifically, but not limited to, lactose, dextrose, sucrose, sorbitol, mannitol, glycine, starch, tragacanth rubber, acacia rubber, calcium phosphate, chloride Petition 870250092262, dated 09 / 10 / 2025, page 43 / 147 40 / 119 calcium, sodium chloride, alginic acid, sodium alginate, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidine, polyethylene glycol, cellulose, water, ethanol, syrup, methylcellulose, methylhydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate, aluminum magnesium silicate, silica, orange essence, strawberry essence, vanilla essence or mineral oil.

[00112] The pharmaceutical composition of the present invention can be administered orally or parenterally (for example, intravenously, hypodermically, intraperitoneally or locally) according to an intended method, wherein its dosage may vary within a range depending on factors such as weight, age, sex, health condition, diet, administration time, method of administration, route of administration, excretion rate, type of disease, severity of disease, treatment period, combined or concomitantly used medication, as well as other factors well known in the medical field, and may be determined by specialists in the field considering all the above factors.

[00113] A daily dosage of the pharmaceutical composition including the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, 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 from about 1 to 1000 mg / kg, preferably from about 5 to 100 mg / kg, and may be administered once daily or several times daily by dividing the daily dosage of the composition. Petition 870250092262, dated 09 / 10 / 2025, p. 44 / 147 41 / 119

[00114] The pharmaceutical composition of the present invention may also include at least one effective ingredient that has equal or similar medicinal effects, in addition to the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[00115] The present invention may provide a method for preventing or treating diseases related to HDAC6 activity or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy, including administering to an individual the compound represented by formula I, II, II-1, II-2, II-3 or II-4 above, 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 that includes them.

[00116] The method for preventing or treating diseases related to histone deacetylase 6 activity or degenerative brain diseases of the present invention may include not only treating the diseases themselves before the manifestation of symptoms, but also inhibiting or preventing such symptoms by administering the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, the compound of at least one of compounds 1 to 8 described in Table 1, stereoisomers thereof or pharmaceutically acceptable salts thereof. In the treatment of diseases, the preventive or therapeutic dose of a given active ingredient may vary depending on the nature and Petition 870250092262, dated 09 / 10 / 2025, p. 45 / 147 42 / 119 severity of the disease or condition, and the route of administration of the active ingredient. The dose and frequency of these may vary depending on the age, weight and reactions of each patient. The appropriate dose and use can be easily selected by those skilled in the art, naturally considering such factors.

[00117] In the method of the present invention, the diseases related to histone deacetylase 6 activity or degenerative brain diseases may be the same as those described above.

[00118] In the present invention, administration may refer to the introduction of a predetermined substance into an individual by an appropriate method.

[00119] In the present invention, individual may refer to all animals, such as rats, mice, cattle, etc., including humans, that are likely to develop or have already developed diseases related to HDAC6 activity or degenerative brain diseases, and specifically may refer to mammals, including but not limited to humans.

[00120] The method for preventing or treating diseases related to the HDAC6 activity of the present invention or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy, may refer to the administration of a therapeutically effective amount of the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, the compound of at least one of compounds 1 to 8 described in table 1, stereoisomers thereof or pharmaceutically acceptable salts thereof. Petition 870250092262, dated 09 / 10 / 2025, p. 46 / 147 43 / 119

[00121] In the present invention, “therapeutically effective amount” may refer to an amount sufficient to treat a disease with a reasonable risk / benefit ratio applicable to medical treatment and not cause a side effect, and may refer to an amount of the compound represented by formula I, II, II1, II-2, II-3 or II-4 above, 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 the prevention or treatment of diseases related to histone deacetylase 6 activity or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy.

[00122] Furthermore, the method for preventing or treating diseases related to the activity of histone deacetylase 6 of the present invention or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy may further include the administration of a therapeutically effective amount of an additional active agent, which is useful in the treatment of the diseases, together with the compound represented by formula I, II, II-1, II-2, II-3 or II-4 above, 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 exhibit a synergistic effect, an additive effect or an adjuvant effect together with the compound represented by formula I, II, II-1, II-2, II-3 or II-4 above, the compound of Petition 870250092262, dated 09 / 10 / 2025, p. 47 / 147 44 / 119 at least one of compounds 1 to 8 described in Table 1, stereoisomers thereof or pharmaceutically acceptable salts thereof.

[00123] The present invention may provide the use of the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, 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 that includes them, for the prevention or treatment of diseases related to HDAC6 activity or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy.

[00124] The present invention may provide the use of the compound represented by formulas I, II, II-1, II-2, II-3 or II-4 above, 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 that includes them, for the preparation of a medicament for the prevention or treatment of diseases related to HDAC6 activity or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy.

[00125] In the application of the present invention, diseases related to histone deacetylase 6 activity or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases, or hereditary neuropathy may be the same as described above. Petition 870250092262, dated 09 / 10 / 2025, page 48 / 147 45 / 119

[00126] For the preparation of the medicament, the compound represented by formulas 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 in a complex preparation together with other active agents, thus providing a synergistic action.

[00127] The matters mentioned in each of the items of the present invention, namely, the oxadiazole-derived compound, its method of preparation, the pharmaceutical composition that includes it, the treatment method that uses it and its use, can be applied in the same way, if they are not contradictory to each other. Advantageous Effects

[00128] A novel compound derived from oxadiazole, stereoisomers thereof or pharmaceutically acceptable salts thereof, according to the present invention, may have a selective inhibitory activity of HDAC6 and exhibit excellent preventive or therapeutic effects in diseases related to HDAC6 activity or atrophy of the nervous system, including central nervous system atrophy, neurodegenerative diseases, including degenerative brain diseases or hereditary neuropathy. Brief Description of the Drawings

[00129] Figures 1 and 2 show the results of evaluating the effect of the compound of the present invention on the relative velocity of mitochondrial axons, which is reduced by treatment with Aβ in hippocampal neurons of Petition 870250092262, dated 09 / 10 / 2025, page 49 / 147 46 / 119 mice.

[00130] Figure 3 shows the results of evaluating the effect of the compound of the present invention on the relative velocity of mitochondrial axons, which is reduced in cultured primary mouse cells in which the P301L mutated human tau protein is overexpressed.

[00131] Figures 4 and 5 show the results of evaluating the effect of the compound of the present invention on tubulin acetylation in SH-SY5Y cells, a human neuroblastoma.

[00132] Figures 6 to 8 show the results of evaluating the effect of the compound of the present invention on cognitive decline due to tauopathy in PS19 mice.

[00133] Figures 9 to 13 show the results of evaluating the effect of the compound of the present invention on the hyperphosphorylation of the tau protein in the brain of PS19 mice.

[00134] Figures 14 and 15 show the results of evaluating the effect of the compound of the present invention on improving long-term memory with a reduced hippocampus in PS19 mice.

[00135] Figures 16 to 19 show the results of evaluating the effect of the compound of the present invention on reduced motor function in Yac128 mice.

[00136] Figure 20 shows the results of evaluating the effect of the compound of the present invention on the relative velocity of mitochondrial axons, which is reduced in an animal model of Charcot-Marie-Tooth disease (MFN2 mutant mice). Petition 870250092262, dated 09 / 10 / 2025, p. 50 / 147 47 / 119

[00137] Figures 21 and 22 show the results of evaluating the 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).

[00138] Figures 23 and 24 show the results of evaluating the 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 (mutant MFN2 mice).

[00139] Figures 25 and 26 show the results of evaluating the 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).

[00140] Figures 27 and 28 show the results of evaluating the 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).

[00141] Figures 29 and 30 show the results of evaluating the 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 (CMT1A mice).

[00142] Figure 31 shows the results of evaluating the effect of the compound of the present invention on nerve conduction velocity, which is reduced in an animal model of Charcot-Marie-Tooth disease (MFN2 mutant mice). Petition 870250092262, dated 09 / 10 / 2025, p. 51 / 147 48 / 119

[00143] Figure 32 shows the results of evaluating the effect of the compound of the present invention on the axon size of sciatic nerve fibers, which is reduced in an animal model of Charcot-Marie-Tooth disease (CX32 null mice). Method for the Invention

[00144] The present invention will now be described in more detail by means of embodiments. These embodiments are provided for the sole purpose of illustrating the present invention and, therefore, it will be evident to those skilled in the art that the scope of the present invention is not limited to them. Preparation of the compound

[00145] A specific method for preparing the compound represented by Formula I is the same as follows. Example 1: Synthesis of compound 1 (compound 1), N-(3-chloro4-fluorophenyl)-N-(4-(5-(difluoromethyl)-1,3,4-oxadiazol-2yl)benzyl)-4-(oxetan-3-yl)piperazin-1-carboxamide

[00146] [Step 1] Synthesis of methyl 4-(((3-chloro-4-fluorophenyl)amino)methyl)benzoate

[00147] 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 N,N-dimethylformamide (80 mL) was stirred at room temperature for 30 minutes, after which 4Petition 870250092262, dated 09 / 10 / 2025, page 52 / 147 49 / 119 (bromomethyl)benzoate (4.581 g, 20.000 mmol) was added to the mixture and further stirred at the same temperature for 18 hours. Water was added to the reaction mixture and extracted with ethyl acetate. An organic layer was washed with a saturated aqueous solution of sodium chloride, dehydrated with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting concentrate was purified by column chromatography (SiO2, 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.

[00148] [Step 2] Synthesis of tert-butyl 4-((3-chloro-4fluorophenyl)(4-(methoxycarbonyl)benzyl)carbamoyl)piperazin1-carboxylate

[00149] A solution of methyl 4-(((3-chloro-4-fluorophenyl)amino)methyl)benzoate (3.711 g, 12.635 mmol) prepared in step 1, N,N-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 piperazine-1-carboxylate (2.353 g, 12.635 mmol) was added to the same and further stirred at room temperature for 18 hours. The solvent was removed from the reaction mixture under reduced pressure, and then a title compound was used without further purification (6.300 g, 98.5%, brown oil). Petition 870250092262, dated 09 / 10 / 2025, page 53 / 147 50 / 119

[00150] [Step 3] Synthesis of methyl 4-((N(3-chloro-4-fluorophenyl)piperazine-1-carboxamido)methyl)benzoate hydrochloride

[00151] A solution of tert-butyl 4-((3-chloro-4-fluorophenyl)(4-(methoxycarbonyl)benzyl)carbamoyl)piperazine-1-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 solid precipitate was filtered, washed with dichloromethane, and dried to obtain a title compound (3.647 g, 66.2%) in a white solid form.

[00152] [Step 4] Synthesis of methyl 4-((N-(3-chloro-4-fluorophenyl)-4-(oxetan-3-yl)piperazine-1-carboxamido)methyl)benzoate

[00153] A solution of methyl 4-((N-(3chloro-4-fluorophenyl)piperazin-1-carboxamido)methyl)benzoate hydrochloride (0.885 g, 2.000 mmol) prepared in step 3, oxetan3-one (0.234 mL, 4.000 mmol) and sodium triacetoxyborohydride (0.848 g, 4.000 mmol) dissolved in dichloromethane (10 mL) Petition 870250092262, dated 09 / 10 / 2025, page 54 / 147 51 / 119 at room temperature was stirred at the same temperature for 18 hours. Water was added to the reaction mixture, extracted with dichloromethane, and filtered through a plastic filter to remove a solid residue and a layer of aqueous solution from it, and then concentrated under reduced pressure. The resulting concentrate was purified by column chromatography (S1O2, 12 g cartridge; methanol / dichloromethane (0 to 5%) and concentrated to obtain a compound of the same titer (0.62 6 g, 67.7%) as a form of brown oil.

[00154] [Step 5] Synthesis of N-(3-chloro-4-fluorophenyl)-N-(4-(hydrazinecarbonyl)benzyl)-4-(oxetan-3-yl)piperazine-1-carboxamide

[00155] A solution of methyl 4-((N-(3-chloro-4-fluorophenyl)-4-(oxetan-3-yl)piperazin-1-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 terminated by lowering the temperature to room temperature. The solvent was removed from the resulting mixture under reduced pressure, and then the resulting concentrate was purified by column chromatography (SiO2, 12 g cartridge; methanol / dichloromethane = 0 to 10%) and concentrated to obtain a title compound (0.435 g, 69.5%) in a white solid form. Petition 870250092262, dated 09 / 10 / 2025, page 55 / 147 52 / 119

[00156] [Step 6] Synthesis of compound 1

[00157] A solution of N-(3-chloro-4-fluorophenyl)N-(4-(hydrazinecarbonyl)benzyl)-4-(oxetan-3-yl)piperazine-1-carboxamide (0.100 g, 0.216 mmol) prepared in step 5, triethylamine (0.091 mL, 0.649 mmol) and 2,2-trifluoroacetic anhydride (0.081 mL, 0.649 mmol) dissolved in dichloromethane (2 mL) at room temperature was stirred at 40 °C for 18 hours, after which a reaction was terminated by lowering the temperature to room temperature. Water was added to the reaction mixture, extracted with dichloromethane, filtered through a plastic filter to remove a solid residue and a layer of aqueous solution from it, and concentrated under reduced pressure. The resulting concentrate was purified by column chromatography (SiO2, 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.

[00158] 1H NMR (400 MHz, CDCX) δ 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), 3.683.65 (m, 1H), 3.49 - 3.47 (m, 4H), 2.43 (brs, 4H); LRMS(ES) m / z 522.4 (M++1). Example 2: Synthesis of compound 2, N-(3-chloro-4-fluorophenyl)N-(4-(5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)-2fluorobenzyl)-4-(oxetan-3-yl)piperazin-1-carboxamide Petition 870250092262, dated 09 / 10 / 2025, p. 56 / 147 53 / 119

[00159] Compound 2 was prepared according to the same reactions as described in steps 1 to 6 of example 1, except for the use of methyl 4-(bromomethyl)-3-fluorobenzoate instead of methyl 4-(bromomethyl)benzoate in step 1 of example 1.

[00160] 1H NMR (400 MHz, CDCls) δ 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), 4.72 (s, 2H), 4,725 (m -4 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). Example 3: Synthesis of compound 3, N-(3-chloro-4-fluorophenyl)N- ((5-(5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)pyridine-2yl)methyl)-4-(oxetan-3-yl)piperazine-1-carboxyl

[00161] [Step 1] Synthesis of 4-((3-chloro-4fluorophenyl)((5-(methoxycarbonyl)pyridin-2yl)methyl)carbamoyl)piperazine-1-carboxylate from tert-butyl

[00162] Methyl 6-(bromomethyl)nicotinate (1.013 g, 4.402 mmol) was added to a solution of tert-butyl 4-((3-chloro-4-fluorophenyl)carbamoyl)piperazine-1-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 stirred at the same temperature for one hour. A saturated aqueous solution of sodium hydrogen carbonate was poured into the reaction mixture and extracted with acetate. Petition 870250092262, dated 09 / 10 / 2025, page 57 / 147 54 / 119 ethyl. An organic layer was washed with a saturated aqueous solution of sodium chloride, dehydrated with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting concentrate was purified by column chromatography (S1O2, 24 g cartridge; ethyl acetate / hexane = 20 to 60%), and concentrated to obtain a title compound (2.000 g, 94.1%) in the form of a yellow solid.

[00163] [Step 2] Synthesis of methyl 6-((N(3-chloro-4-fluorophenyl)piperazine-1-carboxamido)methyl)nicotinate hydrochloride

[00164] A solution of tert-butyl 4-((3-chloro-4-fluorophenyl)((5-(methoxycarbonyl)pyridin-2-yl)methyl)carbamoyl)piperazine-1-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 dichloromethane (50 mL) at room temperature was stirred at the same temperature for 18 hours. A saturated aqueous solution of sodium hydrogen carbonate was poured into the reaction mixture and extracted with dichloromethane. An organic layer was washed with a saturated aqueous solution of sodium chloride, dehydrated with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. Ethyl acetate was added to the resulting concentrate and stirred to filter out a solid precipitate, which was then washed with Petition 870250092262, dated 09 / 10 / 2025, p. 58 / 147 55 / 119 ethyl acetate and then dried to obtain the title compound (1.120 g, 64.0%) in the form of a yellow solid.

[00165] [Step 3] Synthesis of methyl 6-((N-(3-chloro-4fluorophenyl)-4-(oxetan-3-yl)piperazin-1carboxamido)methyl)nicotinate

[00166] Oxetan-3-one (0.194 mL, 3.032 mmol) was added to a solution of methyl 6-((N-(3-chloro-4-fluorophenyl)piperazin-1-carboxamido)methyl)nicotinate hydrochloride (1.120 g, 2.527 mmol) prepared in step 2 and N,N-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 solution of sodium hydrogen carbonate was poured into a reaction mixture, extracted with dichloromethane, filtered through a plastic filter to remove a solid residue and a layer of aqueous solution from it, and concentrated under reduced pressure.The resulting concentrate was purified by column chromatography (SiO2, 24 g cartridge; ethyl acetate = 100%), and concentrated to obtain a product, which was then purified again via chromatography (SiO2, 24 g cartridge; methanol / dichloromethane = 0 to 10%), and concentrated to obtain a titer compound (0.467 g, 39.9%) in a... Petition 870250092262, dated 09 / 10 / 2025, page 59 / 147 56 / 119 form of yellow oil.

[00167] [Step 4] Synthesis of N-(3-chloro-4fluorophenyl)-N-((5-(hydrazinecarbonyl)pyridin-2-yl)methyl)4-(oxetan-3-yl)piperazin-1-carboxamide

[00168] A solution of Methyl 6-((N-(3-chloro-4-fluorophenyl)-4-(oxetan-3-yl)piperazin-1-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 were stirred at 110 °C for 18 hours, after which the reaction was terminated by lowering the temperature to room temperature. The solvent was removed from the reaction mixture under reduced pressure, and then a title compound was used without further purification (0.460 g, 98.5%, yellow solid).

[00169] [Step 5] Synthesis of compound 3

[00170] 2,2-trifluoroacetic anhydride (0.379 mL, 3.046 mmol) was added to a solution of N-(3-chloro-4fluorophenyl)-N-((5-(hydrazinecarbonyl)pyridin-2-yl)methyl)4-(oxetan-3-yl)piperazin-1-carboxamide (0.470 g, 1.015 mmol) prepared in step 4 and imidazole (0.207 g, 3.046 mmol) Petition 870250092262, dated 09 / 10 / 2025, page 60 / 147 57 / 119 dissolved in dichloromethane (10 mL) at room temperature, and refluxed (under heating) for 18 hours, after which a reaction was terminated by lowering the temperature to room temperature. A saturated aqueous solution of sodium hydrogen carbonate was poured into a reaction mixture, extracted with dichloromethane, filtered via a plastic filter to remove a solid residue and a layer of aqueous solution from it, and concentrated under reduced pressure. The resulting concentrate was purified by column chromatography (SiO2, 12 g cartridge; methanol / dichloromethane (0 to 2.5%), and concentrated to obtain compound 3 (0.167 g, 31.5%) in a yellow solid form.

[00171] 1H NMR (400 MHz, CDCla) δ 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). Example 4: Synthesis of compound 4, N-(3,4-dichlorophenyl)-N-(4(5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)-2-fluorobenzyl)-4(oxetan-3-yl)piperazine-1-carboxamide

[00172] [Step 1] Synthesis of 4-(oxetan-3yl)piperazine-1-tert-butyl carboxylate

[00173] Sodium triacetoxyborohydride (11.379 g, 53.688 mmol) was added to a solution of tert-butyl piperazine-1carboxylate (5.000 g, 26.844 mmol) and oxetane Petition 870250092262, dated 09 / 10 / 2025, p. 61 / 147 58 / 119 3-one (2.902 g, 40.266 mmol) dissolved in dichloromethane (200 mL) at room temperature and stirred at the same temperature for 18 hours. A saturated aqueous solution of sodium hydrogen carbonate was poured into the reaction mixture and extracted with dichloromethane. An organic layer was washed with a saturated aqueous solution of sodium chloride, dehydrated with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. Diethyl ether was added to the resulting concentrate and stirred to filter out a solid precipitate, which was then washed with diethyl ether, and then dried to obtain a title compound (6.230 g, 95.8%) in a white solid form.

[00174] [Step 2] Synthesis of 1-(oxetan-3-yl)piperazinetrifluoroacetic acid salt TFA

[00175] A solution of tert-butyl 4-(oxetan-3-yl)piperazine-1-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. The 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 solid precipitate, which was then washed with ethyl acetate and dried to obtain a title compound (4.720 g, 76.7%) in a white solid form.

[00176] [Step 3] Synthesis of N-(3,4-dichlorophenyl) Petition 870250092262, dated 09 / 10 / 2025, page 62 / 147 59 / 119 4-(oxetan-3-yl)piperazin-1-carboxamide

[00177] A solution of 3,4-dichlorophenyl isocyanate (0.300 g, 1.596 mmol) prepared in step 2 and 1-(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.

[00178] [Step 4] Synthesis of N-(3,4-dichlorophenyl)4-(oxetan-3-yl)piperazin-1-carboxamide

[00179] Methyl 4-(bromomethyl)-3-fluorobenzoate (0.173 g, 0.700 mmol) was added to a solution of N(3,4-dichlorophenyl)-4-(oxetan-3-yl)piperazine-1-carboxamide (0.210 g, 0.636 mmol) prepared in step 3 and sodium hydride (60.00%, 0.028 g, 0.700 mmol) dissolved in N,N-dimethylformamide (4 mL) at 0°C and stirred at the same room temperature for 18 hours. The solvent was removed from the reaction mixture under reduced pressure, and then Petition 870250092262, dated 09 / 10 / 2025, page 63 / 147 60 / 119 water was poured into the resulting concentrate, extracted with dichloromethane, filtered through a plastic filter to remove a solid residue and a layer of aqueous solution from it, and concentrated under reduced pressure. The resulting concentrate was purified by column chromatography (S1O2, 4 g cartridge; methanol / dichloromethane = 0 to 5%), and concentrated to obtain a title compound (0.170 g, 53.8%) in a pale yellow solid form.

[00180] [Step 5] Synthesis of N-(3,4-dichlorophenyl)N-(2-fluoro-4-(hydrazinecarbonyl)benzyl)-4-(oxetan-3yl)piperazin-1-carboxamide

[00181] A solution of methyl 4-((N-(3,4-dichlorophenyl)-4(oxetan-3-yl)piperazin-1-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 terminated by lowering the temperature to room temperature. The solvent was removed from the reaction mixture under reduced pressure, and then a title compound was used without further purification (0.170 g, 100.0%, light yellow solid). Petition 870250092262, dated 09 / 10 / 2025, page 64 / 147 61 / 119

[00182] [Step 6] Synthesis of compound 4

[00183] 2,2-trifluoroacetic anhydride (0.128 mL, A concentration of 1.027 mmol) was added to a solution of N-(3,4-dichlorophenyl)-N-(2-fluoro-4-(hydrazinecarbonyl)benzyl)-4-(oxetan-3-yl)piperazine-1-carboxamide (0.170 g, 0.342 mmol) prepared in 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 terminated by lowering the temperature to room temperature. The solvent was removed from the resulting mixture under reduced pressure, and then the resulting concentrate was purified by column chromatography (SiO2, 4 g cartridge; methanol / dichloromethane = 0 to 2.5%) and concentrated to obtain the desired compound 4 (0.020 g, 10.5%) in a white solid form.

[00184] 1H NMR (400 MHz, CDCL·) δ 7.89 (d, J =7.8 Hz, 1H), 7.78 (d, J = 9.9 Hz, 1H), 7.68 (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 -2.17 (m, 4H); LRMS (ES) m / z 556.2 (M++1). Examples 5 to 8: Synthesis of compounds 5 to 8

[00185] Compounds 5, 6, 7 and 8 according to examples 5, 6, 7 and 8 were prepared according to the same reactions as those described in steps 3 to 6 of example 4, Petition 870250092262, dated 09 / 10 / 2025, page 65 / 147 62 / 119 respectively, except for the use of reagent A from Table 2 below instead of 3,4-dichlorophenyl isocyanate in step 3 of example 4, and using reagent B from 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 the NMR data for the same are shown in Table 3. In Table 3 above, compounds 5, 6, 7, and 8 were prepared according to examples 5, 6, 7, and 8, respectively. Table 2 Classification Reagent A Reagent B Yield / property of product obtained from step 3 Yield / property of product obtained from step 4 Yield / property of product obtained from step 5 Yield / property of product obtained from step 6 Example 5 2,5-difluorophenyl 4-(bromomethyl)-3-fluorobenzyl isocyanate methyl 4(bromomethyl)-3-fluorobenzyl oate 0.482 g, 83.8% White solid 0.205 g, 54.8% Colorless oil 0.205 g, 100.0% Light yellow solid 0.136 g, 58.7% White solid Example 6 2,4-dichlorophenyl 4-(bromomethyl)-3-fluorobenzyl isocyanate methyl 4(bromomethyl)-3-fluorobenzyl oate 0.298 g, 56.6% White solid 0.169 g, 53.5% Light yellow solid 0.169 g, 100.0% Light yellow solid 0.002 g, 1.1% Light yellow solid Example 7 2,5-dichlorophenyl-4-(bromomethyl)-3-isocyanate 0.295 g, 0.174 g, 77.2% Solid 0.174 g, 100.0% Solid 0.022 g, 11.3% White solid Petition 870250092262, dated 09 / 10 / 2025, page 66 / 147 63 / 119 Methyl fluorobenzyl isoate 50.9% White solid Light yellow Light yellow Example 8 2,5-dichlorophenyl 6-(bromomethyl)nicotinate methyl isocyanate 0.180 g, 85.5% Brown solid 0.180 g, 100.0% Brown solid 0.004 g, 2.0% White solid Table 3 Compound NMR & LC / MS Compound Name 5 N-(4-(5-(difluoromethyl)1,3,4-oxadiazol-2-yl)-2fluorobenzyl)-N-(2,5difluorophenyl)-4-(oxetan3-yl)piperazine-1carboxamide)δHz ( 4DCN 7.88 (dd, J = 8.0, 1.5 Hz, 1H), 7.80 (t, J = 7.6 Hz, 1H), 7.73 (dd, J = 10.0, 1.5 Hz, 1H), 7.10- 6.80 (m, 4H), J = 4, 4, 4.91 Hz, 2H), 4.58 (t, J = 6.2 Hz, 2H), 3.48- 3.45 (m, 1H), 3.34 (t, J = 4.7 Hz, 4H), 2.19- 2.20 (m, 4H)); LRMS (ES) m / z 524.2 (M+ + 1). 6 N-(2,4-dichlorophenyl)-N-(4(5-(difluoromethyl)-1,3,4oxadiazol-2-yl)-2fluorobenzyl)-4-(oxetan3-yl)piperazine-1carboxamide RMN 1H (400 MHz, Jdd, CDCh, 1 = 9) Γ Hz, 1H), 7.80 (t, J = 7.6 Hz, 1H), 7.73 (dd, J = 10.0, 1.6 Hz, 1H), 7.11- 6.80 (m, 4H), 4.91 (s, 2H), J, 2.63 (t, H = 1 = 4 6.6 Hz, 2H), 4.58 (t, J = 6.2 Hz, 2H), 3.48 3.45 (m, 1H), 3.34 (t, J = 4.8 Hz, 4H), 2.212.20 (m, 4H)); LRMS (ES) m / z 556.3 (M+ + 1).7 N-(2,5-dichlorophenyl)-N-(4(5-(difluoromethyl)-1,3,4oxadiazol-2-yl)-2fluorobenzyl)-4-(oxetan3-yl)piperazine-1carboxamide RMN 1H (400 MHz, Jdd, J7,1 = 8 Hz, 1H), 7.82 (t, J = 7.5 Hz, 1H), 7.70 (dd, J = 9.9, 1.5 Hz, 1H), 7.09- 6.80 (m, 4H), 4.83 (s, 2H), 4.63 (Ht, J 4, = 6). 6.2 Hz, 2H), 3.47- 3.41 (m, 1H), 3.30 (t, J = 4.8 Hz, 4H), 2.16- 2.15 (m, 4H)); LRMS (ES) m / z 556.2 (M+ + 1). 8 N-(2,5-dichlorophenyl)-N-((5(5-(difluoromethyl)-1,3,4oxadiazol-2-yl)pyridin-2yl)methyl)-4-(oxetan-3- RMN 1H (400 MHz, CDCh) δ 1,8,19 (H, J = = 8.2, 2.2 Hz, 1H), 7.71 (d, J = 8.4 Hz, 1H), 7.26- 7.22 (m, 1H), 7.086.82 (m, 3H), 4.98 (s, 2H), 4.68 − m 4.63 Petition 870250092262, dated 09 / 10 / 2025, p. 67 / 147 64 / 119 il)piperazine-1carboxamide 4H), 3.58- 3.52 (m, 1H), 3.36 (t, J = 4.8 Hz, 4H), 2.31 (t, J = 4.8 Hz, 4H)); LRMS (ES) m / z 539.4 (M+ + 1). Protocol for measuring and analyzing the activity of the compound of the present invention. Experimental Example 1. Search for inhibition of HDAC enzyme activity (in vitro)

[00186] An experiment was conducted to identify the selectivity of the compound represented by formula I of the present invention for HDAC6 by means of an experiment on the inhibition of the activity of the enzymes HDAC1 and HDAC6.

[00187] HDAC enzyme activity was measured using the HDAC Drug Discovery Fluorimetric Kit (BML-AK511, 516) from Enzo Life Science, Inc. For the HDAC1 enzyme activity test, recombinant human HDAC1 (BML-SE456) was used as the enzyme source and Fluor de Lys® -“SIRT1 (BML-KI177) was used as the substrate. A five-fold dilution of the compound was divided into a 96-well plate, and then 0.3 μg of enzyme and 10 μm of substrate were added to each well and reacted at 30°C for 60 minutes, after which Fluor de Lys® II Developer (BML-KI176) was added and reacted for 30 minutes and finished. Then, a fluorescence value (Ex 360, Em 460) It was measured using a multi-plate reader (Flexstation 3, Molecular Device). Calbiochem Inc.For the final results, each IC50 value was calculated using the... Petition 870250092262, dated 09 / 10 / 2025, page 68 / 147 65 / 119 GraphPad Prism 4.0 program. Table 4 Example HDAC1 (μM) HDAC6 (nM) HDAC6 selectivity (times) Example HDAC1 (μM) HDAC6 (nM) HDAC6 selectivity (times) 1 > 30 55.2 543 2 > 50 41.4 1207 3 > 50 46.5 1075 4 > 50 45.5 1098 5 > 50 68.3 732 6 > 50 96.6 517 7 > 50 48.6 1028 8 > 50 72.4 690

[00188] As described in Table 4 above, it was confirmed from the results of the HDAC1 and HDAC6 activity inhibition tests that the 1,3,4-oxadiazole oxetane derivative compounds of the present invention, their stereoisomers or pharmaceutically acceptable salts thereof exhibit excellent selective HDAC6 inhibitory activity of about 517 to about 1207 times. Experimental Example 2. Analysis of the inhibitory activity of HDAC6 and selectivity of other HDAC isotypes (in vitro)

[00189] The HDAC6 inhibitory potency and selectivity of a compound represented by compound 5 (example compound 5: compound 5) and of a compound represented by compound 1 (example compound 1: compound 1) were confirmed at the enzymatic level. The present experiment was requested from Reaction Biology Corp. (Malvern, PA, USA) and performed according to a test method established by the organization. Specifically, a serial dilution of the compound represented by compound 5 or the compound represented by compound 1 was split onto a plate, and then a substrate, i.e., RHK-K(Ac)-AMC, and an enzyme, Petition 870250092262, dated 09 / 10 / 2025, p. 69 / 147 66 / 119 were placed together in 50 mM Tris-HCl buffer (pH 8.0, 137 mM NaCl, 2.7 mM KCl, 1 mM MgCl2, 1 mg / mL BSA) to induce a reaction. Then, 50 mM Tris-HCl buffer (pH 8.0, 137 mM NaCl, 2.7 mM KCl, 1 mM MgCl2) containing 2 mM nicotinamide and 16 mg / mL trypsin was added and subjected to the reaction. A fluorescence signal was then measured at 360 nm / 460 nm to measure enzyme activity, and the results are shown in Table 5 below. Table 5 HDAC isotype HDAC1 HDAC2 HDAC3 HDAC4 HDACS HDAC6 HDAC7 HDACS HDAC9 HDAC11 compounds ICSO (nM) ND ND ND ND ND 18.9 ND ND ND ND HDAC isotype HDAC1 HDAC2 HDAC3 HDAC4 HDACS HDAC6 HDAC7 HDACS HDAC9 HDAC11 compound 1 IC50 (nM) ND ND ND ND ND 60 ND ND ND ND

[00190] It was confirmed that the 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 the 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 with excellent HDAC6 inhibitory activity and are highly selective for HDAC6 compared to other HDAC isotypes. Experimental Example 3. Analysis of the effect on mitochondrial axonal migration (in vitro)

[00191] It has been reported that tubulin acetylation, which is a component of microtubules, is reduced in several degenerative brain diseases, and it is known that transport Petition 870250092262, dated 09 / 10 / 2025, page 70 / 147 67 / 119 intracellular metabolism that occurs through microtubules is impaired due to several other intracellular dysfunctions.

[00192] HDAC6 is an enzyme that plays a role in removing tubulin acetylation and, when the enzyme is inhibited, tubulin acetylation is known to increase to stabilize microtubules and have a positive effect on intracellular and axonal transport.

[00193] An experiment with 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, exhibit an effect of improving the relative velocity of mitochondria reduced by treatment with β-amyloid protein fragment (Αβ), which is a substance that causes dementia among neurodegenerative brain diseases, in the neuronal axon, selectively inhibiting HDAC6 activity to increase tubulin acetylation, which is a major substrate of HDAC6.

[00194] Specifically, hippocampal tissue from a mouse embryo obtained from an ICR pregnant mouse was subjected to single-cell suspension, and then hippocampal neurons were cultured in an imaging culture vessel coated with an extracellular matrix for seven days. After seven days of culture, the mouse hippocampal neurons were treated with Aβ at a concentration of 1 μM. 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 μM for three hours, after which Petition 870250092262, dated 09 / 10 / 2025, page 71 / 147 68 / 119 that the migration of stained mitochondria was photographed at low speed using automated cell photography equipment, in order to measure the migration distance per unit of time, thus evaluating the degree of intracellular transport.

[00195] Images were obtained for one minute at one-second intervals to measure the relative velocity per second of each mitochondrion.

[0201] After defining a section in which the relative velocity of mitochondria is significantly reduced compared to the vehicle in the normal group in the β-amyloid-treated group, the normalization results in a vehicle group are shown in Table 6 below. Table 6 Group (Primary neuron) AU Normal Vehicle 1 Αβ Vehicle 0.60 compound 5 300 nM 0.75 Group (Primary neuron) AU Normal Vehicle 1 Αβ Vehicle 0.46 compound 1 300 nM 1.23

[00196] In Table 6 above, Normal refers to a normal group treated with vehicle only (0.5% DMSO) without treatment with β-amyloid (Αβ), and vehicle in β-amyloid refers to a group treated with β-amyloid only and vehicle (0.5% DMSO).

[00197] As shown in Table 6 above, it can Petition 870250092262, dated 09 / 10 / 2025, page 72 / 147 69 / 119 It can be observed that the relative velocity of mitochondria, decreased in the neuronal group treated with Aβ, compared to the normal neuronal group, is increased by three hours of treatment with the compound represented by compound 5 and the compound represented by compound 1, and therefore, 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.

[00198] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including dementia and Alzheimer's disease. Experimental Example 4. Analysis of the effect on the relative axonal velocity of mitochondria when treated for each concentration (in vitro)

[00199] An experiment with this example was conducted to confirm whether the compound represented by compound 5 (compound of example 5: compound 5), according to the present invention, exhibits a concentration-dependent enhancing effect on the relative velocity of mitochondria reduced by treatment with β-amyloid protein fragment (Αβ), which is a substance that causes dementia among neurodegenerative brain diseases, in the neuronal axon, selectively inhibiting HDAC6 activity to increase tubulin acetylation, which is a substrate Petition 870250092262, dated 09 / 10 / 2025, page 73 / 147 70 / 119 main HDAC6.

[00200] Specifically, hippocampal tissue from a mouse embryo obtained from a pregnant female mouse was subjected to single-cell suspension, and then hippocampal neurons were cultured in an imaging culture vessel coated with an extracellular matrix for seven days. After seven days of culture, the mouse hippocampal neurons were treated with Aβ at a concentration of 1 μM. 24 hours later, the resulting neurons were treated with the compound represented by compound 5 at concentrations of 0.01, 0.03, 0.1, 0.3, 1, 3, 10, and 30 μM for three hours, after which the migration of stained mitochondria was photographed at low speed using a confocal microscope in order to measure the migration distance per unit time, thus assessing the degree of intracellular transport.

[00201] Images were obtained for one minute at one-second intervals to measure the relative velocity per second of each mitochondrion. After defining a section in which the relative velocity of the mitochondria is significantly reduced compared to the normal group in the β-amyloid-treated group, the normalization results of a normal group at 100% and a group treated only with β-amyloid at 0% are shown in Table 7 below and in Figure 1. Table 7 Group (Primary Neuron) % Relative Velocity % Normal Increase Vehicle 100 ± 0.06 *** 100 Vehicle 45 ± 0.04 0 0.01 μM 61 ± 0.05 29.29 Petition 870250092262, dated 09 / 10 / 2025, page 74 / 147 71 / 119 Composite Αβ 5 0.03 μΜ 61 ± 0.05 29.20 0.1 μΜ 75 ± 0.07** 55.17 0.3 μΜ 81 ± 0.11*** 65.72 1 μΜ 83 ± 0.03*** 69.34 3 μΜ 81 ± 0.09*** 65.39 10 μΜ 71 ± 0.08** 46.70 30 μΜ 68 ± 0.05* 42.76

[00202] In Table 7 above, Normal refers to a normal group treated with vehicle only (0.5% DMSO) without treatment with β-amyloid (Αβ), and vehicle in β-amyloid refers to a group treated with β-amyloid only and vehicle (0.5% DMSO).

[00203] As shown in table 7 above and in Figure 1 shows that the relative velocity of mitochondria, which is decreased in the neuronal group treated with Aβ compared to the normal neuronal group, is significantly increased in a dose-dependent manner by three hours of treatment with the compound represented by compound 5. Therefore, the relative velocity of mitochondria, which is 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.

[00204] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including dementia and Alzheimer's disease. Experimental Example 5. Duration of Effect Analysis Petition 870250092262, dated 09 / 10 / 2025, page 75 / 147 72 / 119 medicinal in the relative axonal velocity of mitochondria (in vitro)

[00205] An experiment with this example was conducted to confirm the duration of an improvement effect on the relative velocity of mitochondria reduced by treatment with β-amyloid (Αβ) protein fragment of the compound represented by compound 5 (example 5 compound: compound 5) according to the present invention.

[00206] Specifically, hippocampal tissue from a mouse embryo obtained from a pregnant female mouse was subjected to a suspension of individual cells, 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 Aβ at a concentration of 1 μM. 24 hours later, the resulting neurons were treated with the compound represented by compound 5 at a concentration of 0.3 μM for three hours and replaced with fresh culture media. Then, to confirm the persistence of the medicinal effect for 2 to 24 hours without treatment with the compound, the migration of stained mitochondria was slowly photographed using a confocal microscope, and the migration distance per unit time was measured to assess the degree of intracellular transport.

[00207] Images were obtained for one minute at one-second intervals to measure the relative velocity per second of each mitochondrion. After defining a section in which the relative velocity of the mitochondria is significantly reduced compared to the vehicle of Petition 870250092262, dated 09 / 10 / 2025, page 76 / 147 73 / 119 normal group in the group treated with β-amyloid, the normalization results for the 100% vehicle and the 0% β-amyloid treated group are shown in Table 8 below and in Figure 2. Table 8 Group (Primary Neuron) % Relative Velocity % Normal Increase Vehicle 100 ± 0.13 100 Αβ Vehicle 46 ± 0.09 0 Composite 5 (300 nM) No rest period 87 ± 0.06 *** 74.91 Composite 5 (with rest period (hours)) 2 81 ± 0.06** 64.35 4 80 ± 0.07** 62.62 6 82 ± 0.07** 67.13 9 83 ± 0.06 *** 69.12 12 61 ± 0.04 26.77 24 61 ± 0.02 28.77

[00208] In Table 8 above, Normal refers to a normal group treated with vehicle only (0.5% DMSO) without amyloid β (Λβ) treatment, and vehicle in amyloid β refers to a group treated with amyloid β only and vehicle (0.5% DMSO).

[00209] As shown in Table 8 above and Figure 2, it was confirmed that the relative velocity of mitochondria, decreased in the neuronal group treated with Λβ, compared to the normal neuronal group, is significantly increased by three hours of treatment with the compound represented by compound 5, and its medicinal effect continues significantly for up to nine hours, even after removal of the compound by replacement with a new culture medium. Petition 870250092262, dated 09 / 10 / 2025, page 77 / 147 74 / 119

[00210] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including dementia and Alzheimer's disease. Experimental Example 6. Analysis of the effect on the relative axonal velocity of damaged mitochondria in a tauopathy-like situation (in vitro)

[00211] In order to confirm the therapeutic effect of the compound represented by compound 5 (example compound 5: compound 5) in degenerative brain diseases, a tauopathy cell model was prepared and treated with the compound of the present invention, and then an experiment of this example was conducted to confirm the duration of the improvement effect on the relative speed decrease of mitochondria.

[00212] It is known that the Tau protein binds to the microtubules that make up nerve cells, thus contributing to the maintenance of microtubule stability. In pathological conditions such as tauopathy, the Tau protein is separated from the microtubules, which become unstable and adversely affect various cellular functions. Microtubules serve as a pathway that mediates the movement of various organelles, vesicles, and various substances necessary for cellular homeostasis in nerve cells, and in tauopathy conditions, this intracellular transport may not occur normally due to the instability of these microtubules. A test system was Petition 870250092262, dated 09 / 10 / 2025, page 78 / 147 75 / 119 constructed using overcultured mouse cells with overexpressed human tau proteins, exhibiting a P301L mutation that promotes microtubule aggregation and detachment. In this test system, it was evaluated whether the compound represented by compound 5 improves microtubule normalization and intracellular transport.

[00213] Specifically, cerebral cortex tissue from a mouse embryo obtained from a pregnant female mouse was subjected to individual cell suspension and then transfected with a mutant human tau protein expression vector P301L by electroporation. After seven days of culture in a cell incubator, the resulting cells were treated with the compound represented by compound 5 at concentrations of 0.01, 0.1, 0.3, 1, 3, and 10 μM for three hours, after which the migration of stained mitochondria was photographed at low speed through a confocal microscope in order to measure the migration distance per unit time, thus assessing the degree of intracellular transport.

[00214] All results were indicated as mean ± standard error, and the validity of the medicinal effect was determined by statistical significance between the 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's post-hoc test, it was determined as statistically significant, and the test results are shown in Table 9 below and Figure 3. Petition 870250092262, dated 09 / 10 / 2025, page 79 / 147 76 / 119 Table 9 Group % of Relative Velocity % of Normal Increase (P301L_Tau(-)) Vehicle 100.0 100.0 P301LTau Overexpressing neuron Vehicle 61.9 0.0 Composite 5 0.01 μM 78.3 43.0 0.1 μM 85.0 60.5 0.3 μM 89.2 71.7 1 μM 95.7 88.8 3 μM 97.8 94.2 10 μM 93.6 83.2

[00215] In Table 9 above, P301L_Tau (-) refers to a group treated with vehicle only (0.5% DMSO) as a normal neuronal group transfected with a control vector that does not cause tauopathy, and P301L_Tau (+) refers to a group treated with vehicle only (0.5% DMSO) as a diseased neuronal group transfected with an expression vector of the mutant human tau protein P301L.

[00216] As shown in Table 9 above and Figure 3, it can be observed that the decreased relative mitochondrial velocity in the P301L_Tau (+) group compared to the P301L_Tau (-) group is significantly increased in a dose-dependent manner by three-hour treatment with the compound represented by compound 5 and, therefore, the decreased relative mitochondrial velocity in a state of tauopathy is improved by treatment with the compound of the present invention.

[00217] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, diseases Petition 870250092262, dated 09 / 10 / 2025, page 80 / 147 77 / 119 neurodegenerative (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy. Experimental Example 7. Analysis of the inhibitory activity and selectivity of HDAC6 at the neuronal level (in vitro)

[00218] The HDAC6 inhibitory efficacy and selectivity of the compound represented by compound 5 (Example 5 compound: compound 5) and the compound represented by compound 1 (Example 1 compound: compound 1) were confirmed at the neuronal level.

[00219] 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 tubulin acetylation, which is a major substrate of HDAC6.

[00220] Specifically, SH-SY5Y cells, a human neuroblastoma, were fixed in a culture plate and cultured in an incubator for 24 hours. After one day of culture, the SH-SY5Y cells were treated with the compound represented by compound 5 and the compound represented by compound 1 at concentrations of 0.1, 0.3, and 1 μM for three hours. The cells were chemically ground with RIPA buffer, and then the extracted proteins were arranged for each protein size in a polyacrylamide gel by SDS-PAGE. The proteins in the gel were transferred to a nitrocellulose membrane by electrophoresis, and an antibody that selectively binds to the protein to be observed was reacted and visualized in band form to measure the degree of expression, and the results are Petition 870250092262, dated 09 / 10 / 2025, page 81 / 147 78 / 119 shown in Figures 4 and 5.

[00221] In Figures 4 and 5 above, con refers to the result of a cell that was not treated with the compound of the present invention.

[00222] As can be confirmed in Figures 4 and 5 above, it was confirmed that the compound represented by compound 5 and the compound represented by compound 1 significantly increase the acetylation of tubulin.

[00223] Thus, it can be observed that the compounds according to the present invention exhibit an excellent effect of increasing tubulin acetylation. Experimental Example 8. Analysis of brain permeability to the specific HDAC6 inhibitor (in vivo)

[00224] To observe a therapeutic effect of the compound in degenerative brain diseases, the compound exposed to the blood needs to penetrate the blood-brain barrier (BBB) ​​and reach the nerve cells in the brain tissue.

[00225] An experiment with 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 blood-brain barrier (BBB), and reach nerve cells in brain tissue when administered orally.

[00226] Specifically, ICR mice were given the compound represented by compound 5 orally once at a concentration of 10 mg / kg, and blood and brain tissue were collected after 0.5, 2, or 4 hours. The remaining concentration of Petition 870250092262, dated 09 / 10 / 2025, page 82 / 147 The concentration of the compound represented by compound 5 was measured in plasma and brain tissue samples from mouse blood collected using LC-MS / MS (see Rapid Commun. Mass Spectrom. 14, 1729-1735 (2000)). ICR mice received a single oral administration of the compound represented by compound 1 at a concentration of 50 mg / kg, and blood and brain tissue samples were collected after 0.5, 2, or 4 hours. The remaining concentration of the compound represented by compound 1 was measured in plasma and brain tissue samples from mice using LC-MS / MS, and the results are presented in Table 10.

[00227] All results were expressed as mean ± standard deviation of the mean, with the unit of concentration of the compound in the brain being ng / g and the unit of concentration of the compound in plasma being ng / mL. Table 10 Compound | Administered Concentration (mg / kg) | Time after Administration (h) | Concentration (ng / g or ng / mL) | Brain | Plasma | B / P Ratio | Compound | 5 | 10 | 0.5 | 418 ± 76.3 | 968 ± 150 | 0.43 ± 0.02 | 2 | 162 ± 58.3 | 396 ± 121 | 0.41 ± 0.06 | 4 | 62.2 ± 49.3 | 134 ± 106 | 0.46 ± 0.03 | Compound | 1 | 50 | 0.5 | 6014 ± 232 | 14038 ± 705 | 0.57 ± 0.06 | 2 | 6410 ± 1105 | 15049 ± 1228 | 0.62 ± 0.15 4 5245 ± 2143 12715± 3544 0.73 ± 0.09

[00228] As shown in Table 10 above, 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 therefore exhibit high properties. Petition 870250092262, dated 09 / 10 / 2025, page 83 / 147 80 / 119 cerebral permeability.

[00229] Thus, it can be observed that the compounds according to the present invention exhibit excellent cerebral permeability and, therefore, have an excellent effect in the prevention and treatment of nervous diseases, such as brain diseases, central nervous system atrophy, hereditary nervous diseases or the like. Experimental Example 9. Animal behavioral assessment (evaluation of cognitive function)

[00230] The most significant symptom of neurodegenerative diseases is cognitive dysfunction, and various assessment tools to evaluate the cognitive function of patients are used in real clinical trials (MoCA, MMSE, CDR, ADAS-cog, etc.). In animal experiments, the Y-maze, the passive avoidance test, and the water maze test are mainly used as methods of cognitive / learning assessment.

[00231] In order to confirm a therapeutic effect on cognitive dysfunction caused by neurodegeneration, a medicinal effect was confirmed in tauopathic mice (PS19), which were developed by transformation of tau, a protein that causes Alzheimer's disease and tauopathy.

[00232] 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 that develops in people with various mutations in the MAPT gene, a gene that causes tauopathy.

[00233] The tau protein is known to bind to Petition 870250092262, dated 09 / 10 / 2025, page 84 / 147 81 / 119 microtubules that make up nerve cells, thus contributing to the maintenance of microtubule stability. In pathological conditions such as tauopathy, the Tau protein is separated from the microtubules, which become unstable and adversely affect various cellular functions.

[00234] PS19 tauopathic mice are disease model animals that exhibit clinical symptoms of patients with tauopathy, such as increased intracerebral tau proteins and phosphorylated tau, decreased memory and cognitive function, and decreased motor function due to overexpression of the mutant human tau protein P301S, which promotes tau protein aggregation and microtubule detachment.

[00235] The compound of the present invention was administered orally to PS19 tauopathic mice twice daily and, 30 minutes after administration of the test substance, the following behavioral test was performed. Y-maze test

[00236] A Y-maze test was conducted to assess the ability to act sequentially in an experiment to measure short-term memory. The measuring equipment consists of three parts, each 42 cm long, 3 cm wide, 12 cm high, and with a folding angle of 120° for all three parts. This device consisted of white polyvinyl plastic, and the experiment was conducted after defining three branches as A, B, and C, respectively. The experimental animals were placed in the maze, and 1 point (actual alternation) was assigned. Petition 870250092262, dated 09 / 10 / 2025, p. 85 / 147 82 / 119 for each, counting the number of times the animals completely entered each branch, even with their tails entering it, and the case of sequentially entering each branch for eight minutes. An alternating behavior is defined as entering all three branches without overlap, and spontaneous alternating behavior was calculated using the following equation, the results of which are shown in Figures 6 to 8.

[00237] In Figures 6 to 8 above, WT (littermate) is a mouse from a normal group that received 0.5% methylcellulose orally, PS19 (vehicle littermate) is a PS19 mouse (control group) that received 0.5% methylcellulose orally, and PS19 + compound 5 is a group of PS19 mice that received the compound represented by compound 5 orally.

[00238] As confirmed in Figure 6, as a result of repeated (oral) administration of compound 5 (Example 5 compound: compound 5) to 12-week-old tauopathic mice (PS19) for eight weeks, it can be observed that the value of alternating behavior increases significantly compared to the control group (littermate (PS19 vehicle) that received 0.5% methylcellulose), thus demonstrating that the decline in cognitive function caused by tauopathy is mitigated.

[00239] As confirmed in Figure 7, as a result of repeated (oral) administration of compound 5 (Example 5 compound) to 12-week-old tauopathic mice (PS19) for 16 weeks, it can be observed that the value of alternating behavior increases compared to the control group (littermate). Petition 870250092262, dated 09 / 10 / 2025, page 86 / 147 83 / 119 (PS19 vehicle) dosed with 0.5% methylcellulose), thus demonstrating that the decline in cognitive function caused by tauopathy is mitigated.

[00240] As confirmed in Figure 8, as a result of repeated (oral) administration of compound 1 (Example 1 compound: compound 1) to 28-week-old tauopathic mice (PS19) for eight weeks, an increase in the value of alternating behavior was observed compared to the control group (littermate (PS19 vehicle) dosed with 0.5% methylcellulose), thus demonstrating the improvement in cognitive function decline caused by tauopathy.

[00241] Consequently, it has been observed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy. Experimental Example 10. Histopathological Analysis

[00242] After administration of the test substance to PS19 mice, as in Experimental Example 9, a histopathological analysis of the brain tissue was performed after the end of the substance administration. Half an hour after the final administration of compound 5 (compound of example 5: compound 5), the mice were anesthetized with isofluorane and then the brains were extracted. For the double immunofluorescence, brain tissue sections were washed twice with phosphate-buffered saline (PBS) for 15 minutes and reacted with a blocking solution in which bovine serum albumin (Sigma, USA) was Petition 870250092262, dated 09 / 10 / 2025, page 87 / 147 84 / 119 mixed with PBS for two hours. After double washing with PBS, the 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 monoclonal antibodies (Ser202, Thr205) (clone AT8, Anti-fosophosphatau (1:300, Invitrogen, MN1020) and anti-NeuN (1:300, Invitrogen, PA5-78499) were used as primary antibodies. Tissues were then washed with PBS and reacted with secondary antibodies: Alexa488-labeled donkey mouse IgG (1:500, Jackson Immunoresearch, 715-545-150, for phosphotau) and Cy3-labeled donkey mouse IgG (1:500, Jackson Immunoresearch, 711-165-152, for NeuN) at room temperature for three hours. Tissues were then washed again with PBS, fixed on a coated slide, sufficiently dried, and sealed with a DAPI-containing sealant (VECTASHIELD® Antifade Mounting Medium with DAPI, H-1200-10, Vector Laboratories) to prepare a tissue sample.

[00243] Stained brain tissue was photographed using a confocal microscope, and an AT8 staining intensity for each region of the brain tissue was measured in the photographed region using the imageJ program, and the results are shown in Figures 9 to 13.

[00244] In Figures 9 to 13 above, WT (littermate) is a mouse from a normal group dosed with 0.5% methylcellulose, PS19 (vehicle littermate) is a PS19 mouse (control group) dosed with 0.5% methylcellulose, and PS19 + compound 5 is a group of PS19 mice dosed with the compound represented by compound 5.

[00245] As confirmed in Figures 9 to 13 Petition 870250092262, dated 09 / 10 / 2025, page 88 / 147 85 / 119 above, as a result of performing a histopathological analysis for each brain region of the mouse after repeated administration of the compound represented by compound 5 to 12-week-old tauopathic mice (PS19) for eight weeks, it was observed that a degree of hyperphosphorylation (AT8, S202 / T205) of transformed tau is significantly higher in mice from the control group (vehicle littermate) compared to mice from the normal group (WT littermate). Conversely, it was confirmed that animals dosed with the compound represented by compound 5 exhibit significantly improved tau hyperphosphorylation in mice from the control group.

[00246] Thus, it can be observed that the compound represented by compound 5 improves the tau hyperphosphorylation observed in PS19 mice.

[00247] Consequently, it can be observed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy. Experimental Example 11. Electrophysiological Analysis

[00248] After administering the test substance to PS19 mice, as in Experimental Example 9, an electrophysiological analysis was performed on brain tissue after the substance administration was complete. Half an hour after the final administration of compound 5 (Example 5 compound: compound 5), the mice were anesthetized and then the brains were extracted. The extracted brain was Petition 870250092262, dated 09 / 10 / 2025, page 89 / 147 86 / 119 sliced ​​to a thickness of 300 µm to prepare a tissue section containing a hippocampus and transferred to a recording chamber perfused with artificial cerebrospinal fluid (30-32°C) and proceeded.

[00249] A field excitatory post-synthetic potential (fEPSP) recording was obtained using a DAM80 amplifier and WinLTP2.10 software (University of Bristol), filtered at 1 kHz and sampled at 20 kHz. A recording pipette with a resistance of 1-3 MΩ was filled with artificial cerebrospinal fluid. All fEPSPs were recorded in a Schaffer collateral pathway (CA3CA1 synapses) by stimulation with two bipolar electrical stimulators (FHCs) placed in a radial layer or by stimulation with a 20-second interstimulus interval (ISI). A theta burst stimulation (TBS) was administered as a 100 Hz heat stimulation (5 pulses, 20 times) at 5 Hz intervals. The success of LTP induction was confirmed by statistical comparison of the mean slope / amplitude of the fEPSP measured 50 to 60 minutes after TBS with the mean slope / amplitude of the fEPSP measured 10 minutes before TBS.Data analysis was performed using the WinLTP 2.10 reanalysis software (University of Bristol). All data were expressed as mean ± standard error of the mean (SEM), and statistical analysis was performed using statistical software. SPSS version 21 (IBM). Student's t-test was used for the significance test in the comparison of two groups, ANOVA for the significance test in the comparison of groups, and post-analysis of LSD was performed, and the results are shown in Figures 14 and 15. Petition 870250092262, dated 09 / 10 / 2025, pp. 90 / 147 87 / 119

[00250] The significance level was defined as p < 0.05. This means that * or §, p < 0.01; ** or §§, p < 0.01; *** or §§§, p < 0.001.

[00251] In Figure 15 above, in the case of 7 / 2, 7 means the number of brain tissue slices and 2 means the number of mice that were subjected to the evaluation. In the case of 14 / 4, 14 means the number of brain tissue slices and 4 means the number of mice that were subjected to the evaluation.

[00252] In Figures 14 and 15 above, WT (littermate) is a mouse from a normal group that received 0.5% methylcellulose orally, PS19 (vehicle littermate) is a PS19 mouse (control group) that received 0.5% methylcellulose orally, and PS19 + compound 5 is a group of PS19 mice that received the compound represented by compound 5 orally. As confirmed in Figures 14 and 15 above, the hippocampal magnitude of LTP in the control group was found to be significantly reduced compared to the normal group. This means that a neurological pathway associated with memory is degraded.On the other hand, as a result of repeated (oral) administration of the compound represented by the compound in tauopathic mice (PS19) aged 5 to 12 weeks for 16 weeks, it was confirmed that enhanced long-term hippocampal memory is significantly recovered compared to the control group (littermate (PS19 vehicle) dosed with 0.5% methylcellulose).

[00253] Consequently, it can be observed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, Petition 870250092262, dated 09 / 10 / 2025, page 91 / 147 88 / 119 including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including tauopathy. Experimental Example 12. Animal behavioral assessment (motor function assessment)

[00254] To confirm the therapeutic effect of the compound represented by compound 1 (compound of example 1: compound 1) and the compound represented by compound 5 (compound of example 5: compound 5) in degenerative brain diseases, the compound was administered to Yac128 mice, which were model mice for Huntington's disease, and then the improvement in animal motor function was evaluated.

[00255] Huntington's disease is one of the representative degenerative brain diseases and is a genetic disease that causes the death of patients within 15 to 25 years after onset due to severe physical and mental disability. Huntington's disease is an autosomal dominant disease that develops in people who have a mutation in which a CAG sequence is repeated 40 times or more in the HTT gene, responsible for Huntington's disease.

[00256] Yac128 is a Huntington's disease model mouse into which a mutant human HTT gene with 128 repeated CAG sequences is inserted, and is a disease model animal that exhibits clinical symptoms of patients with Huntington's disease, such as expression of mutant human HTT transcripts and proteins, striatal death, and a deterioration of motor functions such as muscle strength and limb coordination. Petition 870250092262, dated 09 / 10 / 2025, p. 92 / 147 89 / 119

[00257] Specifically, the compound represented by compound 1 was administered orally to six-month-old Yac128 mice at a dose of 5.20 mg / kg twice daily for eight weeks, and the compound represented by compound 5 was administered orally repeatedly at doses of 1, 3, 10, and 30 mg / kg twice daily for 12 weeks, and an assessment of motor function was performed at four-week intervals, and the results are shown in Figures 16 to 19.

[00258] In Figures 16 to 19 above, all results are indicated as mean ± standard error, and the validity of the medicinal effect was determined by statistical significance between the control group of Yac128 mice and each test substance group. Regarding statistical analysis, homogeneity of dispersion was identified using ANOVA (one-way ANOVA for single measurement and two-way ANOVA for repeated measurement). As a result of the Dunnett or Bonferroni post-hoc test, statistical significance was determined if the p-value was less than 0.05. Rotarod acceleration and grip strength tests were performed once daily for two days. After that, group separation was performed using a Z-matrix method based on the test results.Yac128 mice were divided into a vehicle delivery group and a compound delivery group (compound represented by compound 1: 5, 20 mg / kg, compound represented by compound 5: 1, 3, 10, 30 mg / kg, administered orally), and the mice in each group were 18 mice. The test substance was administered orally twice daily for eight and 12 weeks, and. Petition 870250092262, dated 09 / 10 / 2025, p. 93 / 147 90 / 119 The exercise function was assessed once daily for two days, at four-week intervals during administration. Rotarod acceleration test

[00259] A rotarod acceleration test (ROTA ROD, LE8205, Panlab) was performed to assess motor coordination / motor function. Prior to the test, all test animals were placed on a rod that accelerated from 4 to 20 rpm three times a day for three days to train adaptation for approximately three weeks, and animals that took 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 over three minutes. A total of six rotarod acceleration tests were conducted three times a day for two consecutive days, and a maximum value among six measured values ​​was used. The results are shown in Figures 16 and 17.

[00260] In Figures 16 and 17 above, WT (wild type) refers to a normal mouse to which the vehicle (0.5% methylcellulose) was administered orally, Yac128 means a control group of Huntington's disease model mice to which the vehicle was administered orally, Yac128 + compound 5 indicates a group in which the compound represented by compound 5 was administered orally to Yac128 mice, and Yac128 + compound 1 represents a group in which the compound represented by compound 1 was administered orally to Yac128 mice.

[00261] As shown in Figure 16 above, the latency to fall, which was reduced in the control group Petition 870250092262, dated 09 / 10 / 2025, p. 94 / 147 91 / 119 Yac128, compared to normal mice, was significantly increased by administration of the compound represented by compound 1 at a dose of 20 mg / kg for four weeks.

[00262] Furthermore, as shown in Figure 17, it can be observed that the fall latency, which was reduced in the Yac128 control group compared to the normal mouse, increases significantly from the moment the compound represented by compound 5 is administered at a dose of 3 mg / kg for one week, and the fall latency increases significantly in most cases over a longer administration period or at a higher concentration, and therefore, the loss of exercise, which is a symptom of Huntington's disease, is mitigated by the administration of the compound of the present invention.

[00263] Consequently, it can be observed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Huntington's disease. Grip strength test

[00264] A grip strength test (BIO-GS3, BIOSEB) was performed to assess muscle strength. The grip strength test evaluated the force exerted on the two forelimbs of a mouse using a bar. All experiments were performed by a single person. When the mouse grips the bar, the tail is gently pulled to obtain grip strength and then pulled with Petition 870250092262, dated 09 / 10 / 2025, page 95 / 147 92 / 119 a 15° incline to measure maximum tension. A total of ten grip strength tests were performed five times a day for two consecutive days, and an average of these values ​​was used, and the results are shown in Figures 18 and 19.

[00265] In Figures 18 and 19 above, WT (wild type) refers to a normal mouse to which the vehicle was administered, Yac128 means a control group of Huntington's disease model mice to which the vehicle was administered, Yac128 + compound 5 indicates a group in which the compound represented by compound 5 was administered to Yac128 mice, and Yac128 + compound 1 represents a group in which the compound represented by compound 1 was administered to Yac128 mice.

[00266] As shown in Figure 18 above, grip strength, which was decreased in the Yac128 control group compared to the normal mouse, was significantly increased in a dose-dependent manner by administration of the compound represented by compound 1 for eight weeks.

[00267] Furthermore, as shown in Figure 19, it can be observed that grip strength, which was reduced in the Yac128 control group compared to the normal mouse, is significantly increased by administration of the compound represented by compound 5 for 12 weeks, and is significantly increased in the groups administered at all concentrations, and therefore, the decrease in muscle strength, which is a symptom of Huntington's disease, is alleviated by administration of the compound.

[00268] Consequently, it can be observed that the Petition 870250092262, dated 09 / 10 / 2025, page 96 / 147 Compound 93 / 119 of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Huntington's disease. Experimental Example 13. Analysis of the effect on increasing the relative axonal velocity of damaged mitochondria in Charcot-Marie-Tooth disease (CMT, HMSN, hereditary motor and sensory neuropathy) (in vitro)

[00269] To confirm the 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) in Charcot-Marie-Tooth disease, an experiment with this example was conducted to confirm the effect of improving the movement speed of reduced mitochondria in the axon of neurons isolated from the dorsal root ganglion of a nine-month-old MFN2 mutant mouse with CMT2A-type Charcot-Marie-Tooth disease induced according to treatment with the compound of the present invention.

[00270] After three days of culture in a cell incubator, mouse neuronal cells obtained by separating the dorsal root ganglia (DRG) of 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 the migration of the stained mitochondria was slowly photographed through a confocal microscope to measure the migration distance per unit time, thus evaluating the degree of Petition 870250092262, dated 09 / 10 / 2025, page 97 / 147 94 / 119 intracellular transport.

[00271] Results were reported as mean ± standard error, and the validity of the medicinal effect was determined by statistical significance between the negative control group and each test substance group. Statistical analysis was performed to confirm the homogeneity of the dispersion using one-way ANOVA, and when a p-value was less than 0.05 by Dunnett's post-hoc test, it was determined to be statistically significant.

[00272] Furthermore, after defining a section in which the relative velocity of mitochondria is significantly reduced in the DRG of MFNR94Q mice compared with the normal group (WT DRG), normalization was performed in the 100% normal group and in the 0% DRG of MFNR94Q mice, and the test results are shown in Table 11 below and in Figure 20.

[00273] In Table 11 above, WT refers to a group in which the vehicle (0.5% methylcellulose) was administered to a normal mouse, and DRG of MFNR94Q mice means a group in which only the vehicle (0.5% methylcellulose) was administered to an MFN2 mutant mouse (group with CMT2A-type induced Charcot-Marie-Tooth disease). Table 11 r Group Relative Speed ​​(Average ± SEM) % (vs Vehicle) WT DRG 1.00 ± 0.02 100.00 Mouse MFNR94<) DR.G 0.62 ± 0.02 0.00 Petition 870250092262, dated 09 / 10 / 2025, p. 98 / 147 95 / 119 Mouse MFNR94Q DRG + 100 nM of compound 0.89 ± 0.04 70.42 Mouse MFNR94QDRG + 300 nM of compound 1 1.17 ± 0.18 144.16 Mouse MFNR94QDRG + 100 nM of compound 5 1.18 ± 0.09 146.70 Mouse MFNR94QDRG + 300 nM of compound 5 1.16 ± 0.21 141.07

[00274] As shown in Table 11 above and Figure 20, it can be observed that the reduced relative mitochondrial velocity in the MFN2 mutation 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 therefore, the reduced relative mitochondrial velocity under a CMT condition is improved by treatment with the compound of the present invention.

[00275] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, including central nervous system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including Charcot-Marie-Tooth disease. Experimental Example 14. Confirmation of the therapeutic effect in CMT [0027 6] CMT is the most common type of inherited peripheral nerve disorder, caused by a mutation in proteins that make up the nerves. More than 1,000 mutations have been identified in about 90 genes so far (Timmerman et al., (2014) Genes 5: 13-32). With the Petition 870250092262, dated 09 / 10 / 2025, p. 99 / 147 96 / 119 Development of Charcot-Marie-Tooth disease (CMT), a progressive degeneration of the peripheral nerves leads to atrophy of the muscles affected by the neural distribution, and therefore, patients present with gradual atrophy of the muscles of the hands and feet, as well as symptoms of deformity in the hands and feet. CMT is genetically and clinically very diverse and complex, and its symptoms are known to range from a near-normal state to a wheelchair-dependent state, depending on the type of mutation. CMT arises mainly in adolescence and occurs in one person in every 2,500 people (Krajewski et al., (2000) Brain 123:1516).

[00277] CMT belongs to the rare diseases as a hereditary disorder of the peripheral nerves. However, its prevalence rate is one person in every 2,500 people. There are approximately 20,000 patients in South Korea and 2,800,000 worldwide. To date, therapy for CMT is limited to rehabilitation, aids, pain management, surgical therapy, etc., but an effective therapeutic agent has not yet been developed. Therefore, there is a great need for the development of a therapeutic agent for CMT.

[00278] For example, regarding CMT, which is the most common type of inherited motor and sensory neuropathy, a large-scale clinical trial was conducted with ascorbic acid, which had been shown to be an essential material for myelination in the peripheral nervous system through a joint culture experiment of lemocytes and dorsal root ganglion cells, but this trial failed to prove its validity (Pareyson et al., (2011) 10(4):3205). In particular, in the case of certain types of diseases, such as Petition 870250092262, dated 09 / 10 / 2025, pp. 100 / 147 97 / 119 CMT1X, CMT2A, etc., a gene that causes the diseases, is highly expressed in the central nervous system. In fact, it has been confirmed that approximately 10% of patients present symptoms such as atrophy of certain brain tissues, including the optic nerve, and visual impairment, thus highlighting the importance of the drug's action on the central nervous system.

[00279] As described above, the compound of the present invention can cross the blood-brain barrier and therefore may have 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).

[00280] Thus, in the following research on two types of CMT disease models, it was confirmed that the compound of the present invention can be advantageously used for the prevention and treatment of CMT, notably improving the motor and sensory functions (rotarod and balance beam tests) of mice with CMT. 14.1 Assessment of motor and sensory functions

[00281] In hereditary neurological diseases, such as Charcot-Marie-Tooth disease (CMT), damage to the nervous system causes gait disturbances, loss of sensation, decreased limb coordination, and similar symptoms. In clinical studies with patients, various assessment tools, such as walking 6 meters, evaluating sensory functions according to the position of the arms and legs, pressing buttons, etc., have been used to assess such functional defects. In addition, in animal experiments, the rotarod test, the balance beam test, and the strength test have been used. Petition 870250092262, dated 09 / 10 / 2025, pp. 101 / 147 98 / 119 grasping tests and similar methods are primarily used to assess symptoms resulting from such damage to the nervous system.

[00282] In the corresponding research, in order to confirm a therapeutic effect of the compound represented by compound 5 (example compound 5: compound 5) on motor and sensory functions in CMT disease, 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. 14.1.1 Results of the study with null CX32 mice

[00283] First, a five-month-old CX32 null mouse received an oral dose of the compound represented by compound 5 at a dose of 10 mg / kg, twice daily, for five months, and motor and sensory functions were evaluated during the administration period. The results are shown in Figures 21 to 22.

[00284] In Figures 21 and 22 below, all results are indicated as mean ± standard error, and the validity of the medicinal effect was determined by statistical significance between the normal group (WT) and each group of the test substance. Regarding statistical analysis, the homogeneity of dispersion was identified using ANOVA (one-way ANOVA for single measurement and two-way ANOVA for repeated measurement). As a result of the Dunnett or Bonferroni post-test, it was determined as statistically significant if the p-value was less than 0.05. Petition 870250092262, dated 09 / 10 / 2025, pp. 102 / 147 99 / 119

[00285] For the corresponding study grouping, the animals were divided into each group according to the Z-array method, based on the animals' body weight before drug administration, values ​​derived from the results of the constant rotarod and balance bar tests, as shown in Table 12 below. Mice received oral administration of the vehicle (0.5% methylcellulose) or 10 mg / kg of the compound represented by compound 5, according to a defined group.

[00286] Null male CX32 mice used for the corresponding study were fed a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with temperature (22 ± 2 °C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed in accordance with the Institutional Animal Care and Use Committee (IACUC) of the Korean Laboratory Animal Center for CKD (approval number: S-22_016). Table 12 Animal Group Dose administered (mg / kg) Route of Administration WT Vehicle 1) - PO2), BID3) CX32 mouse null Vehicle - Compound 5 10 1) Vehicle (Ve h): 0.5% MC 2) PO: Oral Administration 3) BID: twice a day Constant rotarod test

[00287] The rotarod test (LE 8205, Panlab) was Petition 870250092262, dated 09 / 10 / 2025, pp. 103 / 147 The 100 / 119 test was performed to assess forced motor activity and coordination function. For adaptation, all test animals were trained to adapt to 8 rpm, five times a day, for a period of three days, and additionally trained to adapt to 12 rpm, five times a day, for two days. Animals that met a fall latency category of 100-180 seconds were used in subsequent experiments (approximately 80% of the animals met this category). Fall latency 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 of the three measured values ​​was used as the test result (fall latency).

[00288] In Figure 21, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, CX32 null mice represent a control group of mice with a CMT disease model to which the vehicle was administered orally, and CX32 null mice + compound 5 represent a group in which the compound represented by compound 5 was administered orally to a mouse with CMT disease (CX32 null mouse) with inactivated CX32.

[00289] As a result, as shown in Figure 21, it was confirmed that the compound of the present invention exhibits a notable increasing effect on fall latency in null CX32 mice.

[00290] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, neurodegenerative diseases (including diseases Petition 870250092262, dated 09 / 10 / 2025, pp. 104 / 147 101 / 119 neurodegenerative brain diseases) or hereditary neuropathy, including 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). Balance beam test

[00291] The balance beam test was performed to measure motor coordination function and unique limb sensitivity. A rod (1.2 cm wide, 0.6 cm high, and 1.0 m long) was fixed at a 9° incline (45 cm high from the starting point and 60 cm high from the ending point). At the starting point, a mouse was stimulated with a 60 W light, and an ending point was fitted 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 assessment under the same experimental conditions. The mouse was placed at the starting point to walk towards the ending point, and the number of slips after the start was measured. Before the test, the mouse was trained three times a day for two days, and the results from day 3 were used for grouping.Each experiment was evaluated independently by two individuals, and the results are shown in Figure 22.

[00292] In Figure 22 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh means a control group of CMT disease model mice in which the vehicle was administered orally to null CX32 mice, and compound 5 represents a group in which the compound represented by compound 5 was administered orally. Petition 870250092262, dated 09 / 10 / 2025, pp. 105 / 147 102 / 119 to a mouse with CMT disease (CX32 null mouse) with inactivated CX32.

[00293] As shown in Figure 22, it has been confirmed that the compound of the present invention exhibits a notable reduction effect on the slip count and transverse rod time.

[00294] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, neurodegenerative diseases (including neurodegenerative brain diseases) or hereditary neuropathy, including 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). 14.1.2 Results of the study with MFN2 mutant mice

[00295] A six-month-old MFN2 mutant mouse received an oral dose of the compound represented by compound 5 at a dose of 10 mg / kg twice daily for three months. Motor and sensory functions were assessed during the administration period, and the results are shown in Figures 23 to 24. The method of expression and statistical processing for the corresponding results was conducted in the same manner as the study of null CX32 mice above 14.1.1.

[00296] For the corresponding study grouping, the animals were divided into each group according to the Z-array method, based on the animals' body weight before drug administration, the values ​​of which were derived from the results of the acceleration tests. Petition 870250092262, dated 09 / 10 / 2025, pp. 106 / 147 103 / 119 rotarod and balance beam, as shown in Table 13 below. Mice received an oral dose of the vehicle (0.5% methylcellulose) or 10 mg / kg of compound 5, according to a defined group.

[00297] Male MFN2 mutant mice used in the corresponding study received a standard diet (Central Lab Animal, Inc.) and water ad libitum, and were housed in a controlled environment with temperature (22 ± 2 °C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed in accordance with Institutional Animal Care and Use. Committee (IACUC) of the Korea CKD Laboratory Animal Center (with approval number: S-22_012). Table 13 Animal Group Dose Administered (mg / kg) Route of Administration WT Vehicle 1) - PO2), bid3) Compound MFN2*R94Q Vehicle - Compound 5 10 1) Vehicle (Veh): 0.5% MC2) PO: Oral administration3) BID: Twice daily Rotarod acceleration test

[00298] An acceleration rotarod test (LE8205, Panlab) was performed to assess motor coordination / motor function. Prior to the test, all test animals were placed on a rod that accelerated from 4 to 20 rpm three times a day for three days to train adaptation for approximately three weeks, and animals that took 180 seconds or more to fall off the rod were tested. Petition 870250092262, dated 09 / 10 / 2025, pp. 107 / 147 104 / 119 were used for the test. In this experiment, the time for an animal to fall from the rod accelerating from 4 to 40 rpm was measured for three minutes. A total of three rotarod acceleration tests were conducted during one day, and a maximum value among three measured values ​​was used. The results are shown in Figure 23.

[00299] In Figure 23 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to MFN2 mutant mice, and compound 5 represents a group in which the compound represented by compound 5 was administered orally to an MFN2 mutant mouse.

[00300] As a result, as shown in Figure 23, it was confirmed that the compound of the present invention exhibits a notable latency-enhancing effect.

[00301] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). Balance beam test

[00302] A balance beam test was performed to measure motor coordination function and unique limb sensitivity, and a research method was Petition 870250092262, dated 09 / 10 / 2025, pp. 108 / 147 105 / 119 performed in the same manner as the study with CX32 null mice in Figure 14.1.1 above, and the results are shown in Figure 24.

[00303] In Figure 24 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to MFN2 mutant mice, and compound 5 represents a group in which the compound represented by compound 5 was administered orally to an MFN2 mutant mouse.

[00304] As shown in Figure 24 above, it has been confirmed that the compound of the present invention exhibits a notable reduction effect on slip count.

[00305] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). 14.1.3 Results of the study with CMT2A mice

[00306] A six-month-old CMT2A mouse (Mfn2R94Q mutant) was orally administered the compound represented by compound 5 of Example 5 at a dose of 10 mg / kg twice daily for three months. Motor and sensory functions were assessed during the administration period, and the results are shown in Figures 25. Petition 870250092262, dated 09 / 10 / 2025, pp. 109 / 147 106 / 119 to 26. The method of expression and statistical processing for the corresponding results was conducted in the same manner as the study with CX32 null mice above 14.1.1.

[00307] For the corresponding study grouping, the animals were divided into each group according to the Z-array method, based on the animals' body weight before drug administration, whose values ​​were derived from the results of the rotarod acceleration and balance beam tests, as shown in Table 13 below. Mice were administered orally with the vehicle (0.5% methylcellulose) or 10 mg / kg of compound 5, according to a defined group.

[00308] Male CMT2A mice used in the corresponding study received a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with temperature (22 ± 2 °C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed in accordance with the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (approval number: S-22_012). Table 14 Animal Group Dose administered (mg / kg) Route of Administration WT Vehicle 1) - PO2), bid3) CMT2A mice Vehicle - Example 5 (Compound 5) 10 1) Vehicle (Veh): 0.5% MC2) PO: oral administration3) BID: twice daily Petition 870250092262, dated 09 / 10 / 2025, pp. 110 / 147 107 / 119 Rotarod acceleration test

[00309] An acceleration rotarod test (ROTAROD, LE8205, Panlab) was performed to assess motor coordination / motor function. Prior to the test, all test animals were placed on a rod that accelerated from 4 to 20 rpm three times a day for three days to train adaptation for approximately three weeks, and animals that took 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 acceleration rotarod tests were conducted during one day, and a maximum value among three measured values ​​was used. The acceleration rotarod test was conducted for 3 months, and the AUC data (period χ² value measured in the rotarod test) obtained using the prism file are shown in Figure 25.

[00310] In Figure 25 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to CMT2A mice, and compound 5 represents a group in which the compound represented by compound 5 was administered orally to a CMT2A mouse.

[00311] As a result, as shown in FIGURE 25, it was confirmed that the compound of the present invention exhibits a notable latency-enhancing effect.

[00312] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, Petition 870250092262, dated 09 / 10 / 2025, pp. 111 / 147 108 / 119 neurodegenerative diseases (including brain neurodegenerative diseases) or hereditary neuropathy, including Charcot-Marie-Tooth disease, such as peripheral nervous system (PNS) associated Charcot-Marie-Tooth disease (CMT) and central nervous system (CNS) associated Charcot-Marie-Tooth disease (CMT). Balance beam test

[00313] A balance beam test was performed to measure motor coordination function and unique limb sensitivity, and a research method was carried out in the same manner as the study with CX32 null mice in section 14.1.1 above, and the results are shown in Figure 2.

[00314] In Figure 26 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh (TG) means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to CMT2A mice, and compound 5 (TG) represents a group in which the compound represented by compound 5 (Example 5) was administered orally to a CMT2A mouse.

[00315] As shown in Figure 26 above, it has been confirmed that the compound of the present invention (e.g., compound 5 of Example 5) exhibits a notable reduction effect on slip count.

[00316] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of neuronal system atrophy, Petition 870250092262, dated 09 / 10 / 2025, pp. 112 / 147 109 / 119 neurodegenerative diseases (including brain neurodegenerative 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). 14.1.4 Results of the study with CMT1X mice

[00317] A five-month-old CMT1X mouse (Gjb1 KO) was orally administered the compound represented by compound 5 at a dose of 10 mg / kg twice daily for six months. Motor and sensory functions were assessed during the administration period, and the results are shown in Figures 27 to 28. The method of expression and statistical processing for the corresponding results was conducted in the same manner as the study with null CX32 mice of Example 14.1.1 above.

[00318] For the corresponding study grouping, the animals were divided into each group according to the Z-matrix method, based on the animals' body weight before drug administration, values ​​derived from the results of the rotarod acceleration and balance beam tests, as shown in Table 13 below. Mice were orally dosed with the vehicle (0.5% methylcellulose) or 10 mg / kg of compound 5 from Example 5, according to a defined group.

[00319] Male CMT1X mice used in the corresponding study received a standard diet (Central Lab Animal, Inc.) and water ad libitum, and were housed in a controlled environment with temperature (22 ± 2 °C), humidity Petition 870250092262, dated 09 / 10 / 2025, pp. 113 / 147 110 / 119 (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed in accordance with the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (approval number: S-22_012). Table 15 Animal Group Dose administered (mg / kg) Route of administration WT Vehicle1) - PO2), bid3) Mouse - CMT1X Vehicle - Modality 5 (Compound 5) 10 1) Vehicle (Veh): 0.5% MC 2) PO: Oral administration 3) BID: Twice daily Constant rotarod test

[00320] A constant rotarod test (ROTAROD, LE8205, Panlab) was performed to assess motor coordination / motor function. Prior to the test, all test animals were placed on a rod that rotated at 10 rpm three times a day for three days to train adaptation for approximately three weeks, and animals that took 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 over three minutes. A total of three constant rotarod tests were conducted during one day, and a maximum value among three measured values ​​was used. The results are shown in Figure 27.

[00321] In Figure 27 above, a normal group (wild type, WT) refers to a normal mouse to which the Petition 870250092262, dated 09 / 10 / 2025, pp. 114 / 147 111 / 119 vehicle was administered orally, Veh(TG) means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to CMT1X mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was administered orally to a CMT1X mouse.

[00322] As a result, as shown in Figure 27, it was confirmed that the compound of the present invention exhibits a notable latency-enhancing effect.

[00323] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). Balance beam test

[00324] A balance beam test was performed to measure motor coordination function and unique limb sensitivity, and a research method was carried out in the same manner as the study with CX32 null mice of Figure 14.1.1 above, and the results are shown in Figure 28.

[00325] In Figure 28 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh(TG) means a control group of CMT disease model mice in which Petition 870250092262, dated 09 / 10 / 2025, pp. 115 / 147 112 / 119 The vehicle (0.5% methylcellulose) was administered orally to CMT1X mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was administered orally to a CMT1X mouse.

[00326] As shown in Figure 28 above, it has been confirmed that the compound of the present invention (e.g., compound 5 of Example 5) exhibits a notable reduction effect on slip count.

[00327] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). 14.1.5 Results of the study with CMT1A mice

[00328] A six-and-a-half-week-old CMT1A mouse (hPMP22 3-4 copies) was orally administered the compound represented by compound 5 at a dose of 10 mg / kg twice daily for six weeks. Motor and sensory functions were assessed during the administration period, and the results are shown in Figures 29 to 30. The method of expression and statistical processing for the corresponding results was conducted in the same manner as the study of CX32 null mice above 14.1.1.

[00329] For the corresponding study grouping, the animals were divided into each group of Petition 870250092262, dated 09 / 10 / 2025, pp. 116 / 147 113 / 119 according to the Z-array method, based on the animals' body weight before drug administration, values ​​derived from the results of the rotarod acceleration and balance beam tests, as shown in Table 16 below. Mice were administered orally with the vehicle (0.5% methylcellulose) or 10 mg / kg of compound 5 from Example 5, according to a defined group.

[00330] Male CMT1A mice used in the corresponding study received a standard diet (Central Lab Animal, Inc.) and water ad libitum and were housed in a controlled environment with temperature (22 ± 2 °C), humidity (44-56%) and a 12-hour light-dark cycle. All experimental procedures were approved and performed in accordance with the Institutional Animal Care and Use Committee (IACUC) of the Korea CKD Laboratory Animal Center (approval number: S-22_012). Table 16 Animal Group Dose administered (mg / kg) Route of administration WT Vehicle 1) - CMT1A Mouse Vehicle - PO2), BID3) Example 5 (Compound 5) 10 1) Vehicle (Ve h): 0.5% MC 2) PO: Oral administration 3) BID: Twice daily Constant rotarod test

[00331] A constant rotarod test (ROTAROD, The LE8205 test (Panlab) was performed to assess motor coordination / motor function. Before the test, all... Petition 870250092262, dated 09 / 10 / 2025, pp. 117 / 147 114 / 119 test animals were placed on a rod that rotated at 10 rpm three times a day for three days to train adaptation for approximately three weeks, and animals that took 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 over three minutes. A total of three constant rotarod tests were conducted during one day, and a maximum value among three measured values ​​was used. The results are shown in Figure 29.

[00332] In Figure 29 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh(TG) means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to CMT1A mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was administered orally to a CMT1A mouse.

[00333] As a result, as shown in FIGURE 29, it was confirmed that the compound of the present invention (e.g., compound 5 of Example 5) exhibits a notable increasing effect on fall latency.

[00334] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT). Petition 870250092262, dated 09 / 10 / 2025, pp. 118 / 147 115 / 119 associated with the central nervous system (CNS). Balance beam test

[00335] A balance beam test was performed to measure motor coordination function and unique limb sensitivity, and a research method was carried out in the same manner as the study with CX32 null mice of Figure 14.1.1 above, and the results are shown in Figure 30.

[00336] In Figure 30 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh(TG) means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to CMT1A mice, and compound 5(TG) represents a group in which the compound represented by compound 5 (Example 5) was administered orally to a CMT1A mouse.

[00337] As shown in FIGURE 30 above, it has been confirmed that the compound of the present invention (e.g., compound 5 of Example 5) exhibits a notable reduction effect on slip count.

[00338] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT). Petition 870250092262, dated 09 / 10 / 2025, pp. 119 / 147 116 / 119 associated with the central nervous system (CNS). 14.2 Nerve conduction study (NCS)

[00339] Through this experiment, an attempt was made to evaluate the effectiveness of the compound of the present invention, confirming the effect of the compound of the present invention on the nerve conduction velocity of animals.

[00340] The animals used in the nerve conduction study were the animals studied in section 14.1.2, and the nerve conduction study was performed after administration of the compound or vehicle to six-month-old male MFN2 mutant mice for three months.

[00341] The 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 assessed 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. The amplitude of the sensory neuron action potential (SNAP) and the sensory neuron conduction velocity (SNCV) were measured.

[00342] Data were expressed as mean ± SEM, and the statistical significance between the group treated with the compound of the present invention and the vehicle group was analyzed by 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 (version 9.0) and their results are shown in Figure 31. Petition 870250092262, dated 09 / 10 / 2025, pp. 120 / 147 117 / 119

[00343] In Figure 31 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally, Veh means a control group of CMT disease model mice in which the vehicle (0.5% methylcellulose) was administered orally to MFN2 mutant mice, and compound 5 represents a group in which the compound represented by compound 5 was administered orally to an MFN2 mutant mouse.

[00344] As shown in Figure 31, it has been confirmed that the compound of the present invention exhibits a notable improvement effect on the SNAP and SNCV, and is therefore advantageously used in the prevention and treatment of CMT, improving nerve conduction velocity.

[00345] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). 14.3. Histopathological analysis

[00346] 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. 14.3.1 Results of the study with CX32 null mice

[00347] The animals used in the histopathological analysis were the animals studied in section 14.1.1, Petition 870250092262, dated 09 / 10 / 2025, pp. 121 / 147 118 / 119 and histopathological analysis was performed after administration of the compound or vehicle to five-month-old null male CX32 mice for five months.

[00348] After a final treatment with 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 at the University of Ulsan for semi-thin sectioning and staining with toluidine blue (T3260, Sigma).

[00349] A fixed sample was processed by a conventional method for image analysis (see Acta Neuropathologica Communications, volume 7, article number: 144 (2019), Sele et al.), and then a 0.5 μm section was prepared and stained with toluidine blue.

[00350] A histological evaluation was performed under optical microscopy. Pathological changes, including demyelination, remyelination, abnormally thin myelin, and axonal morphological alteration, were investigated from the section. Finally, the diameter of the axons was analyzed with ImageJ software, and the results are shown in Figure 32.

[00351] In Figure 32 above, a normal group (wild type, WT) refers to a normal mouse to which the vehicle was administered orally. Veh signifies a control group of CMT disease model mice, in which the vehicle was administered orally to CX32 null mice. Compound 5 represents a group in which the compound represented by compound 5 was administered orally to a CMT disease mouse (CX32 null mouse) with Petition 870250092262, dated 09 / 10 / 2025, pp. 122 / 147 119 / 119 CX32 deactivated.

[00352] Data were expressed as mean ± standard error of the standard error. Statistical significance between the group treated with the compound of the present invention and the vehicle group was analyzed using one-way ANOVA (posthoc analysis using Dunnett's test) for comparison of three or more groups. All statistical analyses were performed using GraphPad Prism (version 9.0).

[00353] As shown in Figure 32, it has been confirmed that the compound of the present invention noticeably improves the increase in the size of the axon of the sciatic nerve fiber.

[00354] Consequently, it has been confirmed that the compound of the present invention exhibits an excellent effect in the prevention and treatment of 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-Marie-Tooth disease (CMT) associated with the central nervous system (CNS). Petition 870250092262, dated 09 / 10 / 2025, pp. 123 / 147

Claims

1 / 9 CLAIMS 1. Compound represented by Formula I below, stereoisomers thereof or pharmaceutically acceptable salts thereof, characterized in that: [Formula I] in Formula I above, X1 to X4 are each independently N or CRx, wherein three or more of X1 to X4 may not be N at the same time, and Rx is -H, F, Cl, Br or I; R1 is -CXaH2, -C(Xa)2H, or -C(Xa)3, where Xa is F, Cl, Br or I; and R2 and R3 are each independently F, Cl, Br or I.

2. Compound represented by Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof, according to claim 1, characterized in that X1 to X4 are each independently N or CRx, wherein three or more of X1 to X4 may not be N at the same time, and Rx is -H or F; R1 is -CXaH2 or -C(Xa)2H, where Xa is F or Cl; and R2 and R3 are each independently F or Cl.

3. Compound represented by Formula I, the stereoisomers thereof or the pharmaceutically acceptable salts thereof, according to claim 1, characterized in that the compound represented by Formula I above is a compound represented by Formula II below: [Formula II] In Formula II above, X2 is N or CRX, wherein Rx is -H, F, Cl, Br or I; Ri is -CXaH2, -C(Xa)2H, or -C(Xa)3, wherein Xa is F, Cl, Br or I; and R2 and Rs are each independently F, Cl, Br or I.

4. Compound represented by Formula I, stereoisomers thereof, or pharmaceutically acceptable salts thereof, according to claim 1 or 3, characterized in that the compound represented by Formula I above is a compound represented by Formula II-1, II-2, II-3, or II-4 below: Petition 870260074710, 2026-07-27, p. 6 / 18 3 / 9 [Formula II-1] [Formula II-2] In Formula II-1, II-2, II-3, or II-4 above, X2 is independently N or CRX in each Formula, and Rx is H, F, or Cl, Br, or I; Petition 870260074710, 2026-07-27, p. 7 / 18 4 / 9 Ri is independently -CXaH2, -C(Xa)2H, or -C(Xa)3 in each Formula, where Xa is independently H, F, Cl, Br, or I in each Formula; and R2 and R3 are each independently F, Cl, Br, or I in each Formula.

5. Compound represented by Formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof, according to claim 4, characterized in that: in Formula II-i, II-2, II-3, or II-4 above, X2 is independently N or CRx in each Formula, wherein Rx is -H or F; Ri is independently -C(Xa)2H or -C(Xa)3 in each Formula, wherein Xa is independently F or Cl in each Formula; and R2 and R3 are each independently F or Cl in each Formula.

6. Compound having the structure represented by the formula below, its stereoisomers or its pharmaceutically acceptable salts, characterized by the fact that: Table 1 Compound Structure Compound Structure Compound 1 I CM O / z 0 o õ b ^o Compound 2 I CM O / z 0 0, õ b ^o Petition 870260074710, dated 07 / 27 / 2026, page 8 / 18 5 / 9 7. A compound, stereoisomers thereof, or pharmaceutically acceptable salts thereof, according to claim 6, characterized in that the compound is a compound represented by the formula below:

8. Pharmaceutical composition, characterized in that it comprises the compound according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof as an effective component. Petition 870260074710, dated 07 / 27 / 2026, page 9 / 18 6 / 9 9. Pharmaceutical composition according to claim 8, characterized in that the pharmaceutical composition is for preventing or treating diseases mediated by histone deacetylase 6.

10. Pharmaceutical composition, according to claim 9, characterized in that the diseases mediated by histone deacetylase 6 are infectious diseases; neoplasms; endocrinopathies, nutritional and metabolic diseases; mental and behavioral disorders; neurological diseases; ocular and ocular adnexal diseases; circulatory diseases; respiratory diseases; digestive problems; skin and subcutaneous tissue diseases; musculoskeletal and connective tissue diseases; or teratosis, deformities and chromosomal aberrations.

11. Pharmaceutical composition, according to claim 10, characterized in that the infectious diseases are prion diseases; the neoplasm is a benign or malignant tumor; the endocrinopathies, 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 atrophy of the nervous system, including atrophy of the central nervous system, neurodegenerative disease, motor disorder, neuropathy, motor neuron disease or demyelinating disease of the central nervous system; the ocular and ocular adnexal diseases are uveitis; Petition 870260074710, dated 07 / 27 / 2026, p.10 / 18 7 / 9 circulatory diseases are atrial fibrillation or stroke; respiratory diseases are asthma; digestive problems are alcoholic liver disease, inflammatory bowel disease, Crohn's disease, or ulcerative bowel disease; skin and subcutaneous tissue diseases are psoriasis; musculoskeletal and connective tissue diseases are rheumatoid arthritis, osteoarthritis, or systemic lupus erythematosus; and teratoses, deformities, and chromosomal aberrations are autosomal dominant polycystic kidney disease.

12. Pharmaceutical composition, according to claim 11, characterized in that: the nervous system atrophy, comprising central nervous system atrophy, is Huntington's disease, spinal muscular atrophy (SMA) or spinocerebellar ataxia (SCAA); the neurodegenerative disease is Alzheimer's disease or tauopathy; the motor disorder is Parkinson's disease; the neuropathic 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 demyelinating disease of the central nervous system is multiple sclerosis (MS).

13. Pharmaceutical composition, characterized in that it comprises the compound, according to any one of claims 1 to 7, wherein stereoisomers thereof or pharmaceutically acceptable salts thereof, are an effective component for preventing or treating atrophy of the nervous system, including atrophy of the central nervous system, neurodegenerative diseases or neuropathy.

14. Pharmaceutical composition, according to claim 13, characterized in that: the central nervous system atrophy is Huntington's disease, spinal muscular atrophy (SMA) or spinocerebellar ataxia (SCAA); 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. Method for preventing or treating histone deacetylase 6-mediated diseases, characterized in that it comprises 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. Use of the compound, according to any one of claims 1 to 7, characterized in that stereoisomers thereof or pharmaceutically acceptable salts thereof are for the prevention or treatment of histone deacetylase-mediated diseases.

17. Use of the compound, according to any one of claims 1 to 7, stereoisomers thereof or pharmaceutically acceptable salts thereof, characterized in that it is for the preparation of a medicament for the prevention or treatment of histone deacetylase-mediated diseases.

6. Petition 870260074710, dated 07 / 27 / 2026, p. 13 / 18

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