1,3,4-oxadiazole derivatives as histone deacetylase inhibitors

Abstract

The present invention relates to a oxadiazole compound of formula (I) suitable for use as an HDAC6 inhibitor, and also discloses a preparation method thereof and a medical use thereof in treating HDAC6-related diseases or disorders.

Description

Technical Field

[0001] The present invention relates to the field of medicinal chemistry, and more specifically to the field of histone deacetylase (HDAC). Disclosed herein are small organic compounds suitable as HDAC inhibitors, methods for their synthesis, and their use in treating HDAC-related diseases or disorders. Background Art

[0002] Histone deacetylases (HDACs) are epigenetic regulators that regulate chromatin structure and gene expression, and are also increasingly associated with the control of non-epigenetic biological pathways. When the activity levels of these metalloenzymes change, such as when they are overexpressed, dysregulation of natural gene expression and biological processes may occur, ultimately leading to morbidity. In fact, it is well known that HDACs play an important role in different diseases and conditions (such as neurological disorders or cancer). Therefore, controlling HDAC activity (especially by inhibiting it) represents a target therapeutic strategy for the past few decades. HDAC inhibitors of different drug classes are either already on the market - such as Vorinostat for the treatment of lymphoma or valproic acid as an anti-epileptic - or are in development or preclinical and clinical trials for a variety of other conditions such as neurodegenerative conditions.

[0003] HDACs can be divided into classes I to IV based on their precise mode of action. Classes I, II, and IV are defined by zinc-dependent mechanisms, whereas class III HDACs require NAD + As a cofactor. Class II HDACs can also be subdivided into class IIa (HDAC4, -5, -7, -9) and class IIb (HDAC6, -10). Although there may be some functional overlap, these isoforms are generally involved in different biological pathways.

[0004] So-called pan- or broad-spectrum HDAC inhibitors, such as vorinostat mentioned above, target different HDACs with little care. As expected, the use of these inhibitors can result in considerable toxicity. In recent years, HDAC inhibitors that selectively target HDAC isoforms and cause fewer off-target side effects have received more attention. The selective inhibitors include HDAC6 inhibitors. HDAC6 dysregulation is associated with a variety of pathological conditions, and it has been reported that inhibition of this isoform can be used to target cancer, autoimmune and neurodegenerative disorders, inflammation, and a variety of other diseases (Seidel et al., Epigenomics, 2015, 7 (1): 103-118). European patent EP2483242B1 discloses a series of HDAC6 selective inhibitors for the treatment of cancer; and international patent application WO2018 / 087082 reports its usefulness in the treatment of autoimmune diseases. International patent applications WO 2017 / 018805, WO 2017 / 018803 and WO 2017 / 023133 and European patent application EP 3330259 also disclose a method based on HDAC6 inhibitors with oxadiazole moiety.

[0005] Given this enormous therapeutic potential, there is a continuing need to develop potent and selective HDAC6 inhibitors that ideally also possess good pharmacokinetic properties. Furthermore, from an industrial perspective, the direct synthesis of such compounds is desirable. SUMMARY OF THE INVENTION

[0007] The present inventors have surprisingly found a series of compounds which meet the above criteria.

[0008] Thus, in a first aspect, the present invention relates to a compound of formula (I) or a salt, solvate, stereoisomer or prodrug thereof,

[0009]

[0010] in

[0011] one or two of W, X, Y or Z are N, and the remaining ones of W, X, Y and Z are each CH; or each of W, X, Y and Z is CH;

[0012] R1 is H; unsubstituted or substituted alkyl; or halogen; and

[0013] R2 is an unsubstituted or substituted aromatic or non-aromatic heterocyclic ring, wherein the ring contains 1 to 4 nitrogen atoms and wherein one of these ring nitrogen atoms which is the R2 group forms a bond with the rest of formula (I).

[0014] The inventors have also developed methods by which the compounds of the invention can be readily synthesized. Thus, in a second aspect, the present invention provides a method for preparing a compound of the first aspect of the invention.

[0015] Another aspect of the present invention relates to a pharmaceutical composition comprising the compound of the first aspect of the present invention or a salt, solvate, stereoisomer or prodrug thereof, and at least one pharmaceutically acceptable excipient.

[0016] Another aspect of the present invention relates to a compound of formula (I) or a salt, solvate, stereoisomer or prodrug thereof for use as a medicament. The medicament is preferably used for preventing or treating HDAC6-related diseases or disorders. DETAILED DESCRIPTION OF THE INVENTION

[0018] The first aspect of the present invention relates to a compound of formula (I) or a salt, solvate, stereoisomer or prodrug thereof,

[0019]

[0020] in

[0021] one or two of W, X, Y or Z are N, and the remaining ones of W, X, Y and Z are each CH; or each of W, X, Y and Z is CH;

[0022] R1 is H; unsubstituted or substituted alkyl; or halogen; and

[0023] R2 is an unsubstituted or substituted aromatic or non-aromatic heterocyclic ring, wherein the ring contains 1 to 4 nitrogen atoms and wherein one of these ring nitrogen atoms which is the R2 group forms a bond with the rest of formula (I).

[0024] The skilled person understands that when it is stated that W, X, Y or Z is CH, it is the carbon atom of said CH group and not the hydrogen atom that is one of the ring members of the six-membered ring comprising said W, X, Y or Z.

[0025] In one embodiment, two of W, X, Y or Z are N, and the remaining ones of W, X, Y and Z are each CH, in other words, the six-membered ring containing said W, X, Y and Z is a diazine, and in particular a pyridazine, a pyrimidine or a pyrazine. Preferably, the diazine is a pyrimidine, and more preferably a pyrimidine wherein X and Y are N and Z and W are CH.

[0026] In a preferred embodiment, one of W, X, Y or Z is N, and the remaining terms of W, X, Y and Z are each CH, in other words, the six-membered ring containing said W, X, Y and Z is pyridine. In a specific embodiment, it is pyridine in which Z or W is N and the remaining terms of W, X, Y and Z are each CH. In a more preferred specific embodiment, it is pyridine in which X or Y is N and the remaining terms of W, X, Y and Z are each CH.

[0027] In another preferred embodiment, W, X, Y and Z are all CH.

[0028] R1 is H; unsubstituted or substituted alkyl; or halogen.

[0029] In the context of the present invention, the term "alkyl" refers to a straight, branched or cyclic hydrocarbon chain consisting of carbon and hydrogen atoms, which is free of unsaturation, has 1 to 6 carbon atoms (C1-C6 alkyl), preferably 1 to 3 carbon atoms (C1-C3 alkyl), and is connected to the rest of the molecule by a single bond. Some non-limiting examples of alkyl are methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, tert-butyl, n-pentyl or cyclohexyl. Preferred specific alkyls are methyl or ethyl. Methyl is particularly preferred.

[0030] References herein to substitution mean that the designated group may be substituted at one or more available positions with one or more substituents.

[0031] When R1 is substituted alkyl, the substituent may be halogen. Preferred halogens are Cl or F. In one embodiment, halogen is Cl. In another embodiment, halogen is F.

[0032] When R1 is halogen, preferably halogen is Cl or F. In one embodiment, halogen is Cl. In another embodiment, halogen is F.

[0033]

[0046] The term "halogen" as used throughout this disclosure refers to bromine, chlorine, iodine, or fluorine.

[0034] In a preferred embodiment, R1 is H.

[0035] In one embodiment, any of the above R1 embodiments are combined with any of the above W, X, Y, or Z embodiments.

[0036] In a preferred embodiment, the six-membered ring comprising W, X, Y and Z is pyridine, wherein X or Y is N, and the remaining terms of W, X, Y and Z are each CH; and R1 is H.

[0037] In another preferred embodiment, W, X, Y and Z are all CH; and R1 is H.

[0038] R2 is an unsubstituted or substituted aromatic or non-aromatic heterocyclic ring, wherein the ring contains 1 to 4 nitrogen atoms and wherein one of these ring nitrogen atoms which is the R2 group forms a bond with the rest of formula (I).

[0039] In the context of the present invention, the terms "heterocycle" and "heterocyclic ring" are used interchangeably and refer to a 3- to 14-membered ring, preferably a 5- to 10-membered ring, comprising or consisting of carbon and nitrogen atoms. The heterocycle may be aromatic (also referred to herein as a heteroaryl ring or heteroaryl); or non-aromatic, including both saturated or partially unsaturated rings and polycyclic rings comprising at least one aromatic ring and at least one other non-aromatic ring. The heterocycle may be monocyclic or polycyclic, such as monocyclic, bicyclic or tricyclic, or preferably monocyclic or bicyclic. Polycyclic is also referred to in the art as a polycyclic system. In one embodiment, the polycyclic is fused, spirocyclic or bridged, or presents more than one of these types of ring connections. In one embodiment, the polycyclic is a fused or bridged polycyclic, and more preferably it is a fused polycyclic. The bicyclic is preferably a fused bicyclic.

[0040] In a preferred embodiment, the heterocyclic ring is a heteroaryl ring.

[0041] In a preferred embodiment, the heteroaryl ring is a 5-membered monocyclic heteroaryl ring, such as pyrrolyl; oxadiazolyl, such as imidazolyl or pyrazolyl; triazolyl, such as 1,2,3-triazolyl or 1,2,4-triazolyl; or tetrazolyl. More preferably, the heteroaryl ring is an imidazolyl or 1,2,3-triazolyl ring, and more preferably it is a 1,2,3-triazolyl ring.

[0042] In a preferred embodiment, the six-membered ring comprising W, X, Y and Z is pyridine, wherein X or Y is N, and the remaining terms of W, X, Y and Z are each CH; R1 is H; and R2 is imidazolyl.

[0043] In another preferred embodiment, W, X, Y and Z are all CH; R1 is H; and R2 is imidazolyl.

[0044] In a preferred embodiment, the six-membered ring comprising W, X, Y and Z is pyridine, wherein X or Y is N, and the remaining terms of W, X, Y and Z are each CH; R1 is H; and R2 is 1,2,3-triazolyl.

[0045] In another preferred embodiment, W, X, Y and Z are all CH; R1 is H; and R2 is 1,2,3-triazolyl.

[0046] Preferred 1,2,3-triazolyl is 1H-1,2,3-triazolyl.

[0047] In one embodiment, the heteroaryl ring is a 6-membered monocyclic heteroaryl ring, such as pyridinyl, diazinyl, triazinyl or tetrazinyl.

[0048] In a specific embodiment, the six-membered ring comprising W, X, Y and Z is pyridine, wherein X or Y is N, and the remaining terms of W, X, Y and Z are each CH; R1 is H; and R2 is a 6-membered monocyclic heteroaryl ring.

[0049] In a specific embodiment, W, X, Y and Z are all CH; R1 is H; and R2 is a 6-membered monocyclic heteroaryl ring.

[0050] In a preferred embodiment, the heteroaryl ring is a 9-membered bicyclic heteroaryl ring. Preferably, the 9-membered bicyclic heteroaryl ring is formed by fusion of a 6-membered ring with a 5-membered ring. More preferably, it is the nitrogen atom of the 5-membered ring that forms a bond with the rest of formula (I).

[0051] In a preferred embodiment, in the fused ring, the fused bond does not contain a nitrogen atom, i.e. it is a carbon-carbon bond. This means that when the nitrogen atom of the 5-membered ring forms a bond with the remainder of formula (I), the 6-membered ring may contain zero to three nitrogen atoms (in its ring structure, i.e. excluding any nitrogen atom contained by any substituent of the ring).

[0052] In a preferred embodiment, the 6-membered ring does not contain nitrogen atoms (including fused bonds), and therefore the 1 to 4 nitrogen ring atoms of R2 must be 1 to 3 nitrogen ring atoms and must all be contained in the 5-membered ring, (excluding fused bonds). Some examples of such heteroaryl rings are indolyl, benzimidazolyl, indazolyl and benzotriazolyl rings. Most preferably, the heteroaryl ring is a benzimidazolyl or benzotriazolyl ring.

[0053] In any of these embodiments, the 5-membered ring is an imidazolyl or 1,2,3-triazolyl ring, and more preferably it is a 1,2,3-triazolyl ring.

[0054] In a preferred embodiment, the six-membered ring comprising W, X, Y and Z is pyridine, wherein X or Y is N, and the remaining terms of W, X, Y and Z are each CH; R1 is H; and R2 is a benzimidazolyl or benzotriazolyl ring.

[0055] In a specific embodiment, W, X, Y and Z are all CH; R1 is H; and R2 is a benzimidazolyl or benzotriazolyl ring.

[0056] In one embodiment, the heteroaryl ring is a 10-membered bicyclic heteroaryl ring. Preferably, the 10-membered bicyclic heteroaryl ring is formed by 6-membered ring fused to 6-membered ring, and more preferably one of the 6-membered rings does not contain a nitrogen ring atom (including the fusion bond).

[0057] In a specific embodiment, the six-membered ring comprising W, X, Y and Z is pyridine, wherein X or Y is N, and the remaining terms of W, X, Y and Z are each CH; R1 is H; and R2 is a 10-membered bicyclic heteroaryl ring as defined above.

[0058] In a specific embodiment, W, X, Y and Z are all CH; R1 is H; and R2 is a 10-membered bicyclic heteroaryl ring as defined above.

[0059] In any of the above embodiments, the R2 heterocycle may be unsubstituted, or it may be substituted at one or more available positions with a substituent, or, if applicable, with more than one substituent.

[0060] Suitable R2 substituents include:

[0061] - alkyl, alkoxy, thioalkoxy, and halogenated derivatives thereof;

[0062] -halogen;

[0063] -phenyl and phenyl substituted with alkyl, alkoxy, thioalkoxy, or halogenated derivatives thereof, or halogen;

[0064] -=O、-C(=O)R a OR -C(=O)OR a , where R a is an alkyl group as defined above, or a halogenated derivative thereof; and

[0065] - pyridyl and pyridyl substituted by alkyl, alkoxy, thioalkoxy, or halogenated derivatives thereof, or halogen;

[0066] -thienyl, furan or pyrrole and thienyl, furan or pyrrole substituted with an alkyl, alkoxy, thioalkoxy, or a halogenated derivative thereof, or a halogen.

[0067] The R2 substituent is preferably a relatively non-polar group. Therefore, in one embodiment, the R2 substituent is selected from:

[0068] - alkyl, alkoxy, thioalkoxy, and halogenated derivatives thereof;

[0069] -halogen;

[0070] -phenyl and phenyl substituted with alkyl, alkoxy, thioalkoxy, or halogenated derivatives thereof, or halogen;

[0071] The term "alkyl" has the meaning defined above. Preferably, the alkyl group is ethyl or methyl, and even more preferably is methyl.

[0072] In the context of the present invention, the term "alkoxy" refers to a radical of the formula -OR a A group in which R a is an alkyl group as defined above. Preferred alkoxy groups are ethoxy or methoxy, and even more preferred are methoxy groups. In various embodiments, alkoxy refers to an alkyl group in which one of the non-terminal hydrocarbon units of the alkyl chain is replaced by an oxygen atom.

[0073] In the context of the present invention, the term "thioalkoxy" refers to a group of the formula -SR a A group in which R a is an alkyl group as defined above. Preferred thioalkoxy groups are thioethoxy (-SEt) or thiomethoxy (-SMe), and even more preferably thiomethoxy. In a different embodiment, thioalkoxy refers to an alkyl group in which one of the non-terminal hydrocarbon units of the alkyl chain is replaced by a sulfur atom.

[0074] In the context of the present invention, the term "halogenated" refers to halogen substitution, in other words, any of the above-mentioned alkyl, alkoxy, thioalkoxy groups can be completely or partially substituted by halogen atoms. Preferably, the halogen atom is F or Cl, and more preferably F. A preferred specific halogenated substituent is a trifluoromethyl (-CF3) group.

[0075] The term "halogen" has the meaning further defined above. In the following two cases, preferred halogens are Cl and F: when halogen is the R2 substituent, and when phenyl or pyridyl is the R2 substituent when halogen is a substituent of phenyl or pyridyl. In one embodiment, the R2 group, or the phenyl or pyridyl when it is the R2 substituent, is monohalogenated, dihalogenated or trihalogenated, for example monochlorinated, dichlorinated or trichlorinated or monofluorinated, difluorinated or trifluorinated.

[0076] In a particularly preferred embodiment, the R2 substituent is halogen or halogen-substituted phenyl as defined above.

[0077] In a preferred embodiment, R is a 5-membered monocyclic heteroaryl ring as defined in any of the above embodiments, and it is substituted by at least one relatively non-polar group as defined in any of the above embodiments, preferably substituted by phenyl or phenyl substituted by alkyl, alkoxy, thioalkoxy, or a halogenated derivative thereof. In a very preferred embodiment, R is a 5-membered monocyclic heteroaryl ring as defined in any of the above embodiments, and it is substituted by at least one phenyl, such as one or two phenyls, wherein each of these phenyls can be halogenated, such as monohalogenated, dihalogenated or trihalogenated, such as monochlorinated, dichlorinated or trichlorinated, or monofluorinated, difluorinated or trifluorinated. Optionally, in this very preferred embodiment, the 5-membered monocyclic heteroaryl ring is also substituted by the halogen as defined in any of the above embodiments.

[0078] In a preferred embodiment, R is a 9-membered bicyclic heteroaryl ring as defined in any of the above embodiments, and is substituted by at least one relatively nonpolar group selected from alkyl, alkoxy, thioalkoxy, and halogenated derivatives thereof, and halogen as defined in any of the above embodiments. In a very preferred embodiment, R is a 9-membered monocyclic heteroaryl ring as defined in any of the above embodiments, and is substituted by halogen, such as monohalogenated, dihalogenated, or trihalogenated, such as monochlorinated, dichlorinated, or trichlorinated, or monofluorinated, difluorinated, or trifluorinated.

[0079] In a preferred embodiment, the compound of formula (I) is a compound of formula (Ia)

[0080]

[0081] in

[0082] R1, W, X, Y and Z are as defined in any of the above embodiments; and

[0083] R3 and R4 are each independently selected from relatively non-polar groups as defined in any of the above embodiments, or R3 and R4 together with the 4 and 5 positions of the triazole form a 6-membered ring as defined in any of the above embodiments. In a particularly preferred embodiment, R4 is H. The relatively non-polar group is preferably phenyl or phenyl substituted with an alkyl, alkoxy, thioalkoxy, or halogenated derivatives thereof, or halogen, most preferably phenyl substituted with a halogen.

[0084] In a preferred embodiment, the compound of formula (I) is a compound of formula (Ia1)

[0085]

[0086] in

[0087] R1, W, X, Y and Z are as defined in any of the above embodiments;

[0088] R3 is selected from relatively non-polar groups as defined in any of the above embodiments, and is preferably phenyl or phenyl substituted with alkyl, alkoxy, thioalkoxy, or halogenated derivatives thereof, or halogen, most preferably phenyl substituted with halogen; and

[0089] Hal is halogen as defined in any of the above embodiments.

[0090] In one embodiment, the compound of formula (I) is selected from the following list:

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104] The compounds of formula (I) may be in the form of salts, solvates, stereoisomers or prodrugs.

[0105] The term "salt" must be understood as any form of a compound of formula (I) according to the invention, wherein the compound is in ionic form, or is in ionic form and coupled to a counterion (cation or anion). Preferably, the salt is a pharmaceutically acceptable salt, i.e. a physiologically tolerable salt, meaning that it is non-toxic when used in an appropriate manner (i.e. in a reasonable medical dose) for treatment according to the invention, in particular as a result of the counterion.

[0106] The preparation of salt can be accomplished by methods known in the art. Usually, such salt is prepared by reacting the free base form of the compounds of the invention with a suitable base or acid in water or in an organic solvent or in a mixture of the two. Usually, non-aqueous media are preferred, such as ether, ethyl acetate, ethanol, isopropanol or acetonitrile.

[0107] The term "solvate" according to the present invention is understood to mean any compound of formula (I) according to the present invention, wherein the compound is bonded to another molecule (usually a polar solvent) by a non-covalent bond, especially including hydrates and alcoholates, such as methanolates. Preferred solvates are hydrates. Preferably, the solvate is a pharmaceutically acceptable solvate, i.e. a physiologically tolerable solvate, meaning that it is non-toxic when used in an appropriate manner (i.e. in a reasonable medical dose) for treatment according to the present invention, in particular as a result of the solvated molecule.

[0108] As used herein, the term "stereoisomer" refers to an enantiomer, a diastereomer or a mixture thereof, such as a racemate, of a compound of formula (I) according to the present invention. Similarly, the term also encompasses geometric isomers about any double bonds present in the compound of formula (I), i.e., (E)-isomers and (Z)-isomers (trans and cis isomers). In addition, the term also includes rotational isomers of the compound of formula (I).

[0109] Any compound of formula (I) according to the present invention can exist in different tautomeric forms. Specifically, the term "tautomer" refers to one of two or more structural isomers of the compound of formula (I) that exist in equilibrium, and is easily converted into another isomeric form from one isomeric form. Common tautomeric pairs are amine-imines, amide-imidic acid or keto-enol.

[0110] The term "prodrug" refers to derivatives of compounds of formula (I) that are converted in vivo into compounds of formula (I), for example by enzymatic hydrolysis.

[0111] Another aspect of the present invention relates to different methods for preparing compounds of formula (I) as defined above. All references to W, X, Y, Z, R1, R2, R3, R4, Hal and any other variable positions are defined as above for the compounds of the present invention.

[0112] The method of the present invention comprises converting a tetrazole of formula (II) into a tetrazole of formula (I) in the presence of difluoroacetic anhydride (DFAA). The reaction represents a one-pot acylation and thermal decomposition with simultaneous loss of N2. DFAA is added in molar excess relative to tetrazole, for example, a 5 to 30-fold molar excess.

[0113] The reaction is typically carried out at a temperature range of 40 to 120° C. In one embodiment, when one or two of W, X, Y, or Z are N, and the remaining terms of W, X, Y, and Z are each CH, the temperature range is at the lower end of the range, such as 40 to 80° C. In another embodiment, when W, X, Y, and Z are each CH, the temperature range is at the higher end of the range, such as 80 to 120° C.

[0114] Some examples of solvents suitable for the reaction are aromatic hydrocarbons, such as benzene, toluene, or xylene; chlorinated hydrocarbons, such as dichloroethane or chloroform; or acetone. However, in a preferred embodiment, the reaction is carried out in the absence of these solvents, since DFAA is used as both a solvent and an acylating agent. Once the reaction is complete, the compound of formula (I) is separated by standard methods in the art, such as organic extraction and silica gel column chromatography. Oxadiazole.

[0115] DFAA is readily available commercially, for example from Fluorochem Ltd. (#034690).

[0116] Tetrazoles of the formula (II) can be obtained in various ways.

[0117]

[0118] In one embodiment, the tetrazole of formula (II) is obtained as described above in Scheme I (also referred to herein as Method A). This involves reacting the nitrile (III) with an azide ion in the presence of ammonia or an acid addition salt of an amine.

[0119] Representative sources of azide ions are metal azides, especially alkali metal azides, such as sodium azide, or trialkylsilyl azides having one to four carbon atoms in each alkyl group, such as trimethylsilyl azide and triethylsilyl azide. Sodium azide is particularly preferred. The molar ratio of azide to the nitrile of formula (III) is usually maintained in the range of about 1:1 to about 6:1.

[0120] Some examples of suitable acid addition salts are salts with inorganic acids, especially hydrochloric acid, and with organic acids, such as alkanesulfonic acids, such as methane and ethanesulfonic acid, p-toluenesulfonic acid or benzenesulfonic acid. Some examples of suitable amines for forming acid addition salts are tertiary amines, such as trimethylamine, N,N-dimethylaniline, N-methylpiperidine or N-methyl-morpholine. Ammonium chloride is particularly preferred. The molar ratio of the salt to the nitrile of formula (III) is generally maintained in the range of about 1:1 to about 6:1, and is generally at least equimolar with the azide.

[0121] Lewis acid of metal can be used as reaction catalyst. Metal makes nitrile and azide group coordinate and reduces the barrier (barrier) of nucleophilic attack of azide. A variety of catalysts have been reported in the art and include lithium or copper halide salt (such as lithium chloride) or copper iodide or zinc oxide. The catalyst is preferably lithium chloride. The molar ratio of catalyst to the nitrile of formula (III) is usually maintained in the range of about 1:2 to about 2:1.

[0122] The reaction is usually carried out in a reaction-inert solvent. Some examples of reaction-inert solvents suitable for this method are N,N-dimethylformamide (DMF), halogenated hydrocarbons such as dichloromethane (DMC) or chloroform; ethers such as dioxane, tetrahydrofuran (THF); benzene or pyridine. DMF is particularly preferred.

[0123] The reaction is usually carried out at a temperature ranging from 50 to 120°C.

[0124] Acid addition salts of ammonia or amines, as well as azides and metal catalysts are readily commercially available, for example from Sigma-Aldrich (ammonium chloride, #254134; sodium azide, #S2002; lithium chloride, #L4408).

[0125] In one embodiment, the nitrile of formula (III) is obtained by reacting an alkyl halide of formula (V) with a heterocyclic amine of formula (IV) in the presence of a base.

[0126] This alkylation can use different bases, such as alkali metal hydrides, such as NaH; alkali metal hexamethyldisilazane (HMDS), such as LiHMDS; lithium diisopropylamide (LDA); or alkali metal carbonates, such as Na2CO3. Preferred bases are NaH and Na2CO3. Typically, 1 to 3 molar equivalents of the base are used.

[0127] The reaction is preferably carried out in an aprotic solvent such as THF, dioxane, DMF or dimethylsulfoxide (DMSO). The preferred solvent is DMF.

[0128] Preferably, the heterocyclic amine of formula (IV) is first treated with a base to deprotonate the heterocyclic amine, and then the halide of formula (V) is added.

[0129] The reaction can be carried out at a temperature ranging from -78°C to the reflux temperature of the solvent used. Once the reaction is complete, the nitrile of formula (III) is isolated by standard methods in the art such as organic extraction and silica gel column chromatography.

[0130] The halide of formula (V) is typically a bromide, an iodide or a chloride, and more preferably a bromide.

[0131] Halides of formula (V) are commercially available, for example from Sigma Aldrich (4-(bromomethyl)benzonitrile; #144061) or Matrix Scientific (6-bromomethyl-nicotinonitrile; #058787).

[0132] Heterocyclic amines of formula (IV) can also be readily purchased commercially, for example from Sigma Aldrich (imidazole, #56750; tetrazole, #88185; indole, #I3408).

[0133] Bases are also readily available commercially, for example from Sigma Aldrich (sodium hydride; #223441).

[0134] However, in one embodiment, the halide of formula (V) can be prepared by halogenation of the corresponding alkyl compound of formula (VI), ie, reaction of the alkyl compound of formula (VI) with a halogenating agent.

[0135] The halogenating agent can be any conventional halogenating agent. Some examples of such halogenating agents are brominating agents, such as bromine, hydrogen bromide, N-bromosuccinimide (NBS), cupric bromide, tetramethylammonium tribromide, trifluoroacetyl hypobromite, dibromoisocyanuric acid; iodizing agents, such as iodine, iodine chloride, trifluoroacetyl hypoiodite, and N-iodosuccinimide, etc.; or chlorinating agents, such as chlorine, thionyl chloride, N-chlorosuccinimide or cupric chloride. Among them, N-bromosuccinimide, N-iodosuccinimide and N-chlorosuccinimide are preferred. The amount of the halogenating agent is preferably 1 to 4 molar equivalents relative to the alkyl compound of formula (VI).

[0136] Some examples of solvents that can be used for the halogenation reaction include hydrocarbons such as heptane, hexane, cyclohexane, pentane, toluene and xylene; ethers such as diethyl ether, THF or dioxane; halogenated hydrocarbons such as chloroform or DCM; DMF, ethyl acetate, DMSO or MeCN. The solvent is preferably DMF.

[0137] The above halogenation reaction is preferably carried out in the presence of a free radical initiator. Some examples of free radical initiators include 2,2'-azobisisobutyronitrile (AIBN), 1,1'-azobis(cyclohexane-1-carbonitrile) (V-40), benzoyl peroxide or (PhCOO)2. A preferred free radical initiator is AIBN. The amount of the free radical initiator is preferably 0.01 to 0.5 molar equivalent relative to the alkyl compound of formula (VI).

[0138] The reaction is generally carried out at a temperature of 0 to 100° C. Once the reaction is complete, the halide of formula (V) is isolated by standard methods in the art such as organic extraction and silica gel column chromatography.

[0139] Alkyl compounds of formula (VI) are readily commercially available, for example from Sigma Aldrich (p-toluonitrile; #132330) or from Acros Organics (5-cyano-2-methylpyridine; #15259816); as are halogenating agents and free radical initiators, for example from Sigma-Aldrich (N-chlorosuccinimide, #109681; AIBN, #441090).

[0140] In a different embodiment, the tetrazole of formula (II) is obtained as described in Scheme II below (also referred to herein as Method B).

[0141]

[0142] Method B is particularly applicable to compounds of formula (Ia) above.

[0143] Tetrazole of formula (IIa) can be obtained from nitrile (IIIa) in the same manner as described above for converting nitrile (III) to tetrazole (II).

[0144] Nitriles (IIIa) can be prepared from azides (IVa) by reacting azides (IVa) with alkynes of formula (X). This reaction represents a 1,3-cycloaddition between the azide and alkyne functional groups.

[0145] The reaction is usually carried out using a copper (I) catalyst. Cu (I) catalysts such as copper iodide, copper chloride or copper bromide can be used directly, preferably copper iodide, or Cu (II) substances such as copper sulfate or copper acetate can be used, together with a reducing agent such as ascorbate, such as sodium ascorbate, and these two substances react to produce Cu (I) catalytic substances in situ. When copper (I) substances are used directly, ultrasonic treatment and / or alkali are usually used to increase the reaction rate. Some examples of suitable alkalis are amine bases, such as trimethylamine, 1,8-diazabicyclo [5.4.0] 11 carbon-7-ene (DBU) or N, N-diisopropylethylamine (DIPEA). A preferred initiator is DIPEA.

[0146] The cycloaddition can be carried out in a variety of solvents, such as protic solvents (e.g., alcohols or water); or aprotic solvents (e.g., THF, DMSO, DMF, toluene or acetone). The solvent is preferably DMF.

[0147] The reaction is usually carried out with equimolar amounts of azide (IVa) and alkyne (X), and when a copper catalyst is used, it is usually added in a catalytic amount. When a base is used, it is usually used in a molar excess.

[0148] The cycloaddition can be carried out under mild conditions, for example at room temperature (20 to 25° C.), but can also be carried out at higher temperatures or under microwave irradiation. Once the reaction is complete, the nitrile of formula (IIIa) can be isolated by standard methods in the art such as organic extraction and silica gel column chromatography.

[0149] Copper catalysts and bases are readily available commercially, for example from Celtic Chemicals (copper iodide, #P400) or from Sigma-Aldrich (DIPEA, #387649).

[0150] The azide compound of formula (IVa) can be prepared by reacting the halide of formula (V) with an azide. Carefully select conditions so that no cycloaddition occurs between the nitrile group of the azide compound of formula (IVa). This is achieved by converting in a system similar to that used to convert (V) into (VIIa), except that much milder conditions are used. Specifically, the reaction is carried out at room temperature and does not use an acid addition salt or catalyst of ammonia or amine.

[0151] The halides of formula (V) and alkyl compounds of formula (VI) can be prepared as described above.

[0152] In an alternative approach according to Method B, a tetrazole of formula (IIa) is prepared from an azide of formula (VIIa) and an alkyne of formula (X) using the same reaction as described above for the conversion of an azide of formula (IVa) to a nitrile of formula (IIIa).

[0153] In contrast to the approach carried out by intermediates (IVa) and (IIIa), which carries out three independent reactions, namely the nucleophilic substitution of the N3 group is introduced, and nitrile and alkyne cycloaddition, the approach carried out by intermediate (VIIa) provides a one-step N3 nucleophilic substitution and nitrile cycloaddition. This one-step double conversion can be achieved by using the same reaction as the tetrazole of the above-mentioned tetrazole of formula (IIa) converted into the nitrile of formula (IIIa), only ensuring the use of at least two molar equivalents of azide relative to the halide of formula (V). Surprisingly, the approach carried out by intermediates (IVa) and (IIIa) is particularly suitable for compounds in which one or two of W, X, Y or Z are N and the remaining items in W, X, Y and Z are each CH, because better overall yields are obtained when compared with the approach carried out by intermediate (VIIa).

[0154] In a different embodiment, the tetrazole of formula (II) is obtained as described in Scheme III below (also referred to herein as Method C).

[0155]

[0156] Method C is particularly suitable for compounds of formula (Ia1) above.

[0157] The halogenated tetrazole of formula (IIa1) can be obtained from the halogenated nitrile (IIIa1) in the same manner as described above for converting the nitrile (IIIa) into the tetrazole (IIa).

[0158] The halogenated nitrile of formula (IIIa1) can be prepared from cuprous acetylide of formula (VIII) by reacting cuprous acetylide of formula (VIII) with an azide compound of formula (IVa) in the presence of a halogenating agent.

[0159] The halogenating agent may be, for example, those described above for converting the alkyl compound of formula (VI) into the halide of formula (V), however, the halogenating agent is preferably an N-halosuccinimide.

[0160] The azide, cuprous acetylide and halogenating agent may be added to the reaction mixture simultaneously, but better yields of the halogenated nitrile of formula (IIIa1) are obtained if the azide is reacted first with cuprous acetylide to form an intermediate 1,2,3-triazole cuprous intermediate, and the halogenating agent is subsequently added.

[0161] The azide compound, cuprous acetylide and halogenating agent may be used in equimolar amounts, however the azide compound and halogenating agent are generally used in very slight excess, for example, 1.1 to 2 times molar amount with respect to the azide compound.

[0162] Solvents commonly used for the transformation are chlorinated hydrocarbons such as DCM, dichloroethane or chloroform.

[0163] The reaction can be carried out at room temperature or higher, for example from 20°C to the reflux temperature of the solvent. If halogenation at other positions is undesirable, for example halogenation at the R1 position, the conditions can be adjusted to avoid this, for example by adopting mild reaction conditions, for example by carrying out the reaction at room temperature rather than at reflux temperature, or by reducing the reaction time.

[0164] Once the reaction is complete, the halogenated nitrile of formula (IIIa1) can be isolated by standard methods in the art such as organic extraction and silica gel column chromatography.

[0165] Cuprous acetylide of formula (VIII) can be obtained by reacting the corresponding alkyne of formula (IX) with a copper (I) species.

[0166] A representative Cu(I) species is a copper(I) halide, such as copper iodide or copper chloride. Alternatively, a Cu(II) species (such as copper sulfate) together with a reducing agent (such as hydroxylammonium chloride) may also be used. The Cu(I) species is preferably CuI.

[0167] The reaction is usually carried out by dissolving the copper halide in a solvent that is less acidic than the alkyne, such as an ethereal solvent, e.g., diethyl ether, THF; chlorinated and non-chlorinated hydrocarbons, e.g., dichloromethane or toluene; or trimethylamine, ammonia or ammonium hydroxide. Preferably, the reaction is carried out in ammonium hydroxide.

[0168] Alkynes of formula (IX) or (X) are readily commercially available, for example from Sigma Aldrich (phenylacetylene, #117706; ethynyltoluene, #206504; or chloro-4-ethynylbenzene #206474).

[0169] Copper (I) or copper (II) materials suitable for the above reactions can also be purchased from, for example, Sigma Aldrich (copper (I) chloride, #651745; copper (II) sulfate, #451657).

[0170] In an alternative approach according to method C, the tetrazole of formula (IIal) is prepared directly from the azide of formula (VIIa) and cuprous acetylide of formula (VIII), using the same reaction as described above for the azide of (IVa) and cuprous acetylide of formula (VIII) to produce the halogenated nitrile of formula (IIIa1). It was unexpectedly found that the approach via intermediates (IVa) and (IIIa1) is particularly suitable for compounds in which one or two of W, X, Y or Z are N and the remaining terms of W, X, Y and Z are each CH, because better overall yields are obtained than when proceeding via intermediate (VIIa).

[0171] Various modifications of the above-described synthetic methods within the common knowledge of a person skilled in the art may be used to obtain the various compounds of formula (I) of the present invention.

[0172] For example, when R1 is halogen, any of the above formula (I) Oxadiazoles can be simply halogenated using the halogenation conditions described above.

[0173] Another aspect of the present invention relates to a pharmaceutical composition comprising at least one compound of formula (I) or a salt, solvate, stereoisomer or prodrug thereof, and at least one pharmaceutically acceptable excipient. The term "excipient" refers to a component other than the active ingredient in a pharmaceutical compound (as defined by the European Medicines Agency -EMA). It preferably includes "carriers, excipients and / or carriers". A carrier is a form in which a substance is incorporated to improve the delivery and effectiveness of a drug. Pharmaceutical carriers are used in drug delivery systems (e.g., controlled release technology) to prolong the drug effect in the body, reduce drug metabolism, or reduce drug toxicity. Carriers are also used to improve the effectiveness of drug delivery to pharmacological target sites. Excipients are substances added to pharmaceutical preparations that affect the effect of the active ingredient in a predictable manner. A carrier is an excipient or substance used as a medium for providing a large amount of drug administration, preferably without therapeutic effect (Stedman's Medical Devices). 2006 Lippincott Williams & Wilkins). Such pharmaceutical carriers, excipients or vehicles can be sterile liquids, such as water and oils, including those of petroleum, animal, plant or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil, etc. Suitable pharmaceutical carriers are described in "Remington's Pharmaceutical Sciences" by EW Martin. The choice and amount of these excipients will depend on the application form of the pharmaceutical composition. The pharmaceutical composition according to the present invention can be in any suitable form for its application in humans and / or animals, preferably humans (including infants, children and adults), and can be produced by conventional methods known to those skilled in the art, such as those described or mentioned in the Spanish and US Pharmacopoeias and similar reference texts.

[0174] The pharmaceutical composition of the present invention can be in any form suitable for drug administration, such as intraperitoneal, intramuscular, intraarticular, intravenous, intraarterial, intravesical, intraosseous, intracavernous, pulmonary, buccal, sublingual, ocular, intravitreal, intranasal, transdermal, rectal, vaginal, oral, epidural, intrathecal, intraventricular, intracerebral, intraventricular, intracisternal, intraspinal, perispinal, intracranial or topical administration. Suitable pharmaceutical forms for oral administration can be tablets and capsules, and can contain conventional excipients known in the art, such as binders, such as syrup, gum arabic, gelatin, sorbitol, tragacanth or polyvinylpyrrolidone; fillers, such as lactose, sugar, corn starch, calcium phosphate, sorbitol or glycine; lubricants for preparing tablets, such as magnesium stearate; disintegrants, such as starch, polyvinylpyrrolidone, sodium starch glycolate or microcrystalline cellulose; or pharmaceutically acceptable wetting agents, such as sodium lauryl sulfate. The pharmaceutical form suitable for parenteral administration may be a sterile solution, suspension or lyophilized product. Suitable excipients such as fillers, buffers or surfactants may be used.

[0175] Another aspect of the present invention relates to a compound of formula (I) or a salt, solvate, stereoisomer or prodrug thereof for use as a medicament. In a preferred embodiment, the medicament is for preventing or treating a HDAC6-related disease or disorder.

[0176] Similarly, the present invention also relates to a method for preventing or treating an HDAC6-related disease or disorder in a subject in need thereof, the method comprising administering to the subject a compound of formula (I) or a pharmaceutically acceptable salt, solvate, stereoisomer or prodrug thereof.

[0177] Similarly, the present invention also relates to the use of the compound of formula (I) or a pharmaceutically acceptable salt, solvate, stereoisomer or prodrug thereof in the preparation of a medicament for preventing or treating HDAC6-related diseases or disorders.

[0178] Similarly, the present invention also relates to the use of the compound of formula (I) or a pharmaceutically acceptable salt, solvate, stereoisomer or prodrug thereof for preventing or treating HDAC6-related diseases or disorders.

[0179] As used herein, HDAC6-related diseases or disorders refer to diseases or disorders mediated (at least in part) by HDAC6. Some examples of such diseases or disorders are summarized below: Van Helleputte et al., 2014, Research and Reports in Biology, 5: 1-13; Seidel et al., Epigenomics, 2015, 7 (1): 103-118; Ke et al., Mol Med, 2018, 24: 33; Jian et al., Neuroscience Letters, 2017, 658: 114-120.

[0180] In one embodiment, the HDAC6-associated disease or disorder is selected from: cancer, such as prostate cancer, multiple myeloma, or glioblastoma multiforme; inflammation; a neurodegenerative disorder, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, spinal muscular atrophy, or Charcot-Marie-Tooth disease; an autoimmune disease, such as multiple sclerosis, rheumatoid arthritis, or autoimmune hepatitis; a peripheral neuropathy, such as chemotherapy-induced neuropathy or diabetic neuropathy; a major depression disorder; a renal disease, such as autosomal dominant polycystic kidney disease, lupus nephritis, or acute kidney injury; or transplant rejection.

[0181] In addition to its ability to selectively target HDAC6, it is surprisingly found that the compounds of the present invention also have good brain barrier permeability. Therefore, a preferred embodiment of the present invention relates to compounds of formula (I) for treating or preventing central nervous system HDAC6-related diseases or disorders (e.g., the above-mentioned neurodegenerative diseases or disorders, multiple sclerosis or depression).

[0182] In the context of the present invention, the term "treat" or grammatical variations thereof refers to the improvement or elimination of a disease or condition.

[0183] In the context of the present invention, the term "prevent" or "preventing" or grammatical variations thereof refers to reducing or eliminating the risk of progression, occurrence or recurrence of a disease or condition.

[0184] The compounds of the present invention can be used together with at least another drug to provide a combination therapy. The additional one or more drugs can be part of the same composition, or can be provided as a separate composition and can be administered simultaneously or at different times. In one embodiment, more than one compound of the present invention can be used in combination with each other, such as the case of Examples 12, 57 or 58 described herein. In such a combination, such as in the case of Examples 12, 57 or 58, different compounds of the present invention can be present in different amounts relative to each other.

[0185] It was also unexpectedly discovered that the compounds of the present invention possess a favorable solubility profile as well as improved genotoxicity, properties that are generally lacking in HDAC6 inhibitors.

[0186] Generally, the compounds of the invention are used in therapeutically effective amounts. What constitutes a therapeutically effective amount of any given compound of the invention can be determined by a medical professional based on a variety of factors, such as the relative potency of the compound selected, the severity of the condition being treated, or the weight or age of the patient.

[0187] The following illustrative, non-limiting examples are provided to aid the understanding of the present invention.

[0188] Synthesis of the compounds of the present invention

[0189] Unless otherwise stated, reagents and substrates were purchased from commercial suppliers (Cymit Quimica SL and Sigma-Aldrich). Thin layer chromatography (TLC) analysis was performed on silica gel 60 F254 using aluminum plates and visualized with UV light. Flash chromatography was performed on a silica gel 60 (230 to 400 mesh) column. MS analysis was performed using electrospray ionization (ESI) mode at 30 eV. 1 H NMR, recorded at 400 or 500 MHz using CDCl3 or dimethyl sulfoxide (DMSO) as solvent 1 H NMR spectrum. Purity was determined by HPLC using a reversed phase stationary phase.

[0190] A) Some examples of synthesis according to method A of the present invention

[0191] The compound of formula (I) was synthesized by applying the following synthetic scheme:

[0192]

[0193] N-bromosuccinimide (15.6mmol, 2.37g) and azobisisobutyronitrile (AIBN) (1.56mmol, 0.256g) were added to a solution of the corresponding alkylaryl compound derivative (15.6mmol) in acetonitrile. The reaction mixture was refluxed for 2 hours and azobisisobutyronitrile (0.78mmol, 0.128g) was added. After refluxing for one hour, the mixture was stirred at room temperature for 16 hours. Then, the solvent was evaporated under reduced pressure, and the crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain the desired bromide compound.

[0194]

[0195] At 0 ℃, NaH (60%, in mineral oil, 1.6mmol, 0.062g) or NaCO (2.3mmol, 0.244g) is added to the solution of the corresponding bromide compound (1mmol) in N, N-dimethylformamide (DMF). After 30 minutes, the corresponding heterocyclic amine is added. The reaction is monitored by thin layer chromatography (TLC). After the reaction is complete, NHCl (saturated aqueous solution) is added, and the product is extracted with ethyl acetate. The organic layer combined is dried, filtered and concentrated. Residue is purified by flash chromatography (silica gel, ethyl acetate / hexane or MeOH / CHCl).

[0196]

[0197] Subsequently, NaN (4.7 mmol, 0.305 g), NH4Cl (4.7 mmol, 0.251 g) and LiCl (1.7 mmol, 0.071 g) were added to a solution of the corresponding nitrile compound (1.0 mmol) in N,N-dimethylformamide at room temperature. The reaction mixture was stirred at 100 ° C and monitored by TLC until the reaction was complete. The crude reaction mixture was directly used for the next step.

[0198]

[0199] At room temperature, difluoroacetic anhydride (DFAA) (20.0mmol, 2.5ml) was added to the crude reaction obtained in the previous step. The reaction mixture was stirred at 60°C (when one or two of W, X, Y or Z were N) or 100°C (when W, X, Y and Z were CH respectively). The reaction process was monitored by HPLC-MS. After the reaction was completed, water was added and the solution was extracted with ethyl acetate. The combined organic fractions were washed with water and brine, dried and evaporated under reduced pressure with Na2SO4. The crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain the desired product with high purity (>90%).

[0200] Some representative examples prepared using this protocol are:

[0201] Example 1: 2-(4-((1H-indol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0202]

[0203] Orange solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.02 (d, J=8.3Hz, 1H), 7.81-7.77 (m, 1H), 7.61-7.53 (m, 3H), 7.45-7.39 (m, 2H), 7.31 (d, J = 8.1Hz, 1H), 7.13-7.08 (m, 1H), 7.03 (t, J = 7.4Hz, 1H), 6.55-6.52 (m, 1H), 5.57 (app d, J=8.6Hz, 2H); MS (ESI, m / z): 326.28[M+1] + .

[0204] Example 2: 2-(4-((1H-pyrrolo[3,2-b]pyridin-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0205]

[0206] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.35 (dd, J=4.7, 1.3Hz, 1H), 8.03 (d, J=8.3Hz, 2H), 7.91-7.86 (m, 2H), 7.54 (t, J=51.4Hz, 1H), 7.43 (d, J=8.2Hz, 2H), 7.12 (dd, J=8.3, 4.6Hz, 1H), 6.66 (d, J=3.3Hz, 1H), 5.62 (s, 2H); MS (ESI, m / z): 327.08[M+1] + .

[0207] Example 3: 2-(4-((1H-pyrrolo[3,2-c]pyridin-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0208]

[0209] White solid;1 H NMR (δppm, 400MHz, DMSO-d6) 8.99 (s, 1H), 8.28 (d, J = 6.0Hz, 1H), 8.04 (d, J = 8.3Hz, 2H), 7.79 (d, J = 3.3Hz, 1H), 7.71 (d, J = 6.0Hz, 1H), 7.55 (t, J=51.3Hz, 1H), 7.45 (d, J=8.1Hz, 2H), 6.83 (d, J=3.2Hz, 1H), 5.68 (s, 2H); MS (ESI, m / z): 327.08[M+1] + .

[0210] Intermediates :

[0211] 4-((1H-Pyrrolo[3,2-c]pyridin-1-yl)methyl)benzonitrile

[0212]

[0213] MS (ESI, m / z): 234.00 [M+1] + .

[0214] 1-(4-(1H-tetrazol-5-yl)benzyl)-1H-pyrrolo[3,2-c]pyridine

[0215]

[0216] MS (ESI, m / z): 277.20 [M+1] + .

[0217] Example 4: 2-(4-((1H-pyrrolo[2,3-b]pyridin-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0218]

[0219] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 1H NMR (δppm, 400MHz, DMSO-d6) 8.27 (dd, J=4.6, 1.6Hz, 1H), 8.04-7.99 (m, 3H), 7.70 (d, J=3.5Hz, 1H), 7.54 (t, J=51.4Hz, 1H), 7.44 (d, J=8.3Hz, 2H), 7.13 (dd, J=7.8, 4.7Hz, 1H), 6.57 (d, J=3.5Hz, 1H), 5.62 (s, 2H); MS (ESI, m / z): 327.26[M+1] + .

[0220] Example 5: 1-(1-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)-1H-indol-3-yl)-2,2-difluoroethanone

[0221]

[0222] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 8.50-8.45 (m, 1H), 8.21-8.09 (m, 3H), 7.39 (d, J=7.0Hz, 1H), 7.38-7.32 (m, 3H), 7 .29 (d, J=2.7Hz, 1H), 6.93 (t, J=51.7Hz, 1H), 6.15 (t, J=54.2Hz, 1H), 5.54 (s, 2H).MS (ESI, m / z): 402.25[M-1] - .

[0223] Example 6: 2-(4-((1H-indazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0224]

[0225] Orange solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.18 (s, 1H), 8.02 (d, J=8.1Hz, 2H), 7.81 (dd, J=8.3, 3.5Hz, 1H), 7. 74 (d, J=8.8Hz, 1H), 7.54 (t, J=51.4Hz, 1H), 7.44-7.38 (m, 3H), 7.20-7.15 (m, 1H), 5.82 (s, 2H),

[0226] Regiochemistry was determined by nOe; MS (ESI, m / z): 327.26 [M+1] + .

[0227] Example 7: 2-(4-((2H-indazol-2-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0228]

[0229] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.58 (d, J=0.9Hz, 1H), 8.06 (d, J=8.2Hz, 2H), 7.75 (d, J=8.4Hz, 1H), 7.55 (t, J=5 1.4Hz, 1H), 7.61 (d, J=8.7Hz, 1H), 7.53 (d, J=8.2Hz, 2H), 7.28-7.23 (m, 1H), 7.11-7.02 (m, 1H), 5.80 (s, 2H),

[0230] Regiochemistry confirmed by nOe; MS (ESI, m / z): 327.05 [M+1] + .

[0231] Example 8: 2-(4-((1H-benzo[d]imidazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0232]

[0233] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.58 (d, J=0.9Hz, 1H), 8.06 (d, J=8.2Hz, 2H), 7.75 (d, J=8.4Hz, 1H), 7.55 (t, J=51.4Hz, 1H), 7 .61 (d, J=8.7Hz, 1H), 7.53 (d, J=8.2Hz, 2H), 7.28-7.23 (m, 1H), 7.11-7.02 (m, 1H), 5.80 (s, 2H); MS (ESI, m / z): 327.03[M+1] + .

[0234] Example 9: 1-(5,6-dichloro-1-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)-1H-benzo[d]imidazol-2-yl)-2,2-difluoroethanone

[0235]

[0236] Yellow solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.38 (s, 1H), 8.35 (s, 1H), 8.03 (d, J = 8.3Hz, 2H), 7.55 (t, J = 51.4Hz, 1H ), 7.42 (d, J=8.3Hz, 2H), 7.20 (t, J=53.2Hz, 1H), 6.01 (s, 2H); MS (ESI, m / z): 471.09 and 473.12[M+1].

[0237] Example 10: 2-(4-((5,6-dichloro-1H-benzo[d]imidazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0238]

[0239] White solid; 1 H NMR (δ ppm, 400 MHz, DMSO-d6) 8.61 (s, 1H), 8.06 (d, J = 8.1 Hz, 2H), 8.00 (s, 1H), 7.97 (s, 1H), 7.55 (t, J = 51.4 Hz, 1H), 7.54 (d, J = 8.7 Hz, 2H), 5.68 (s, 2H); MS (ESI, m / z): 395.21 and 397.20 [M+1] +

[0240] Example 11: 2-(4-((1H-benzo[d][1,2,3]triazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0241]

[0242] Mortar-colored solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.10 (d, J=8.4Hz, 1H), 8.08-8.04 (m, 2H), 7.89 (d, J=8.4Hz, 1H), 7.54 (t, J=51.4Hz, 1H), 7.59-7.53 (m, 3H), 7.46-7.42 (m, 1H), 6.15 (s, 2H); MS (ESI, m / z): 328.24[M+1] + .

[0243] Example 12: Example 12 as its three triazole regioisomers, namely 2-(difluoromethyl)-5-(4-((5-methyl-1H-benzo[d][1,2,3]triazol-1-yl)methyl)phenyl)-1,3,4- oxadiazole, 2-(difluoromethyl)-5-(4-((6-methyl-1H-benzo[d][1,2,3]triazol-1-yl)methyl)phenyl)-1,3,4- oxadiazole, 2-(difluoromethyl)-5-(4-((5-methyl-2H-benzo[d][1,2,3]triazol-2-yl)methyl)phenyl)-1,3,4- Mixtures of oxadiazoles were tested in the bioassays. Although the three regioisomers can be separated by standard methods in the art, such as by silica gel column chromatography, they are presented herein as a mixture because this is how they were tested in the bioassays mentioned below.

[0244]

[0245] White solid; as a mixture of three regioisomers (distribution 1:1:1); MS (ESI, m / z): 342.25 [M+1] + .

[0246] Example 13: 2-(4-((6-chloro-1H-benzo[d][1,2,3]triazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0247]

[0248] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.17 (d, J = 1.8Hz, 1H), 8.14 (d, J = 8.8Hz, 1H), 8.09-8.05 (m, 2H), 7.59-7.55 (m, 2H), 7.54 (t, J=51.4Hz, 1H), 7.47 (dd, J=8.8, 1.9Hz, 1H), 6.12 (s, 2H),

[0249] Regiochemistry confirmed by nOe enhancement between protons at 6.12 ppm and 8.17 ppm; MS (ESI, m / Z): 362.18 and 364.21 [M+1] + .

[0250] Example 14: 1-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)naphthalene-2(1H)-one

[0251]

[0252] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.05 (d, J=10, 1Hz, 1H), 8.03 (d, J=8.7Hz, 2H), 7.79 (dd, J=7.8, 1.5Hz, 1H), 7.54 (t, J=51.4Hz, 1H), 7.53-7.50 ( m, 1H), 7.45 (d, J = 8.2Hz, 2H), 7.39 (d, J = 8.6Hz, 1H), 7.27 (t, J = 7.4Hz, 1H), 6.77 (d, J = 9.5Hz, 1H), 5.65 (s, 2H).; MS (ESI, m / z): 354.30 [M+1] + .

[0253] Example 15: 1-(4-(5-(difluoromethyl)-1,3,4- oxadiazol-2-yl)benzyl)-3,3-dimethylindolin-2-one

[0254]

[0255] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.03 (d, J=8.3Hz, 2H), 7.53 (t, J=536Hz, 1H), 7.52 (d, J=8.3Hz, 2H), 7.39 (dd, J=7.6, 1.5Hz, 1H), 7.1 8 (td, J=7.7, 1.3Hz, 1H), 7.04 (td, J=7.5, 1.0Hz, 1H), 6.91 (d, J=7.8Hz, 1H), 5.02 (s, 2H), 1.35 (s, 6H); MS (ESI, m / z): 370.27[M+1] + .

[0256] Example 16: 2-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)isoindoline-1,3-dione

[0257]

[0258] White solid; 1H NMR (δppm, 400MHz, DMSO-d6) 8.04 (d, J=8.3Hz, 2H), 7.97-7.92 (m, 2H), 7.92-7.87 (m, 2H) , 7.58 (d, J=8.1Hz, 2H), 7.55 (t, J=51.4Hz, 1H), 4.90 (s, 2H); MS (ESI, m / z): 356.26[M+1] + .

[0259] Example 17: 2-(Difluoromethyl)-5-(4-((5-phenyl-1H-tetrazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0260]

[0261] White solid; MS (ESI, m / z): 355.28 [M+1] + .

[0262] Example 18: 1-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)-4-phenyl-1H-1,2,4-triazol-5(4H)-one

[0263]

[0264] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.58 (s, 1H), 8.10-8.06 (m, 2H), 7.76-7.72 (m, 2H), 7.60-7.52 (m, 4H), 7.54 (t, J=58.9Hz, 1H), 7.45-7.38 (m, 1H), 5.12 (s, 2H); MS (ESI, m / z): 370.24[M+1] + .

[0265] Example 19: 1′-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)spiro[cyclohexane-1,3′-indolin-2′-one

[0266]

[0267] White solid; 1H NMR (δppm, 400MHz, DMSO-d6) 8.07-8.01 (m, 2H), 7.60 (dd, J=7.5, 1.2Hz, 1H), 7.55 (t , J=51.8Hz, 1H), 7.54 (d, J=8.5Hz, 2H), 7.23 (td, J=7.7, 1.2Hz, 1H), 7.07 (td, J=7.5, 1, 0Hz, 1H), 6.93 (d, J=7.8Hz, 1H), 5.04 (s, 2H), 4, 11 (ddd, J=11.7, 7.6, 4.2Hz, 2H), 3 .87 (dt, J=11, 6, 4.9Hz, 2H), 1.84 (dt, J=9.3, 4.6Hz, 4H).MS (ESI, m / z): 412.33[M+1] + .

[0268] Example 20: 2-(4-(1-(1H-benzo[d]imidazol-1-yl)ethyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0269]

[0270] White solid; 1 H NMR (400MHz, chloroform-d) 8.19 (s, 1H), 8.12 (d, J = 8.4Hz, 2H), 7.87 (d, J = 8.1Hz, 1H), 7.38 (d, J = 8.3Hz, 2H), 7.33-7.30 (m, 1H), 7.23 (t, J = 7.5Hz, 1H), 7.15 (d, J=8.2Hz, 1H), 6.93 (t, J=51, 7Hz, 1H), 5.74 (q, J=7.1Hz, 1H), 2.10 (d, J=7.1Hz, 3H); MS (ESI, m / z): 341.27[M+1] + .

[0271] Example 21: 2-(6-((1H-benzo[d][1,2,3]triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0272]

[0273] Yellow oily substance; 1H NMR (δppm, 400MHz, DMSO-d6) 9.13 (d, J=2.2Hz, 1H), 8.47 (dd, J=8.2, 2.3Hz, 1H), 8.10 (d, J=8.4Hz, 1H), 7.84 (d, J= 8.3Hz, 1H), 7.60-7.54 (m, 2H), 7.56 (t, J=58.2Hz, 1H), 7.47-7.42 (m, 1H), 6.27 (s, 2H); MS (ESI, m / z): 329.43[M+1] + .

[0274] Example 22: 2-(6-((5,6-dichloro-1H-benzo[d]imidazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0275]

[0276] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.16-9.13 (m, 1H), 8.54 (s, 1H), 8.46 (dd, J=8.2, 2.3Hz, 1H), 8.00 (s, 1H), 7. 97 (s, 1H), 7.58 (d, J=7.7Hz, 1H), 7.51 (t, J=51.0Hz, 1H), 5.80 (s, 2H); MS (ESI, m / z): 396.22 and 398.22[M+1] + .

[0277] Example 23: 2-(6-((3H-[1,2,3]triazolo[4,5-b]pyridin-3-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0278]

[0279] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.09 (d, J=2.2Hz, 1H), 8.76 (dd, J=4.5, 1.4Hz, 1H), 8.65 (dd, J=8.3, 1.4Hz, 1H) , 8.47 (dd, J=8.2, 2.3Hz, 1H), 7.65 (d, J=8.2Hz, 1H), 7.57-7.53 (m, 1H), 7.57 (t, J=51.1Hz, 1H), 6.25 (s, 2H),

[0280] Regiochemistry confirmed by nOe enhancement between protons only at 6.25 ppm and 7.65 ppm; MS (ESI, m / Z): 330.20 [M+1] + .

[0281] Example 24: 2-(6-((5,6-dichloro-1H-benzo[d][1,2,3]triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0282]

[0283] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.11 (d, J=2.2Hz, 1H), 8.55 (s, 1H), 8.48 (dd, J=8.2, 2 .3Hz, 1H), 8.40 (s, 1H), 7.65 (d, J=8.2Hz, 1H), 7.58 (t, J=51.2Hz, 1H), 6.29 (s, 2H),

[0284] Regiochemistry confirmed by nOe enhancement between protons at 6.29 ppm and 8.40 ppm; MS (ESI, m / z): 397.20 and 399.16 [M+1] + .

[0285] Example 25: 2-(6-((5,6-dichloro-2H-benzo[d][1,2,3]triazol-2-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0286]

[0287] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.16 (d, J=2.2Hz, 1H), 8.50 (dd, J=8.1, 2.3Hz, 1H), 845 (s, 2H), 7.65 (d, J=8.3Hz, 1H), 7.59 (t, J=51.2Hz, 1H), 6.30 (s, 2H),

[0288] Regiochemistry confirmed by nOe enhancement between protons at 6.30 ppm and 7.65 ppm only; MS (ESI, m / z): 397.22 and 399.20 [M+1] + .

[0289] Example 26: 2-(Difluoromethyl)-5-(6-((4-phenyl-1H-imidazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0290]

[0291] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.35 (d, J=2.2Hz, 1H), 8.40 (dd, J=8.2, 2.3Hz, 1H), 7.84-7.78 (m, 2H), 7.75 (s, 1H), 7 .40 (t, J=7.6Hz, 2H), 7.30-7.27 (m, 1H), 7.33 (s, 1H), 7.23 (d, J=8.2Hz, 1H), 6.96 (t, J=51.6Hz, 1H), 5.41 (s, 2H),

[0292] Regiochemistry was determined by nOe enhancement between protons at 5.41 ppm and protons at 7.23 ppm, 7.33 ppm and 7.75 ppm; MS (ESI, m / z): 354.26 [M+1]+.

[0293] Example 58: 2-(6-((5,6-dichloro-2-(trifluoromethyl)-1H-benzo[d]imidazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0294]

[0295] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.05-9.03 (m, 1H), 8.48 (dd, J=8.2, 2.2Hz, 1H), 8.30 (s, 1H), 8.27 (s, 1 H), 7.67 (d, J=8.3Hz, 1H), 7.57 (t, J=51.2Hz, 1H), 6.01 (s, 2H); MS (ESI, m / z): 464.19 and 466.19[M+1] + .

[0296] Example 59: 2-(Difluoromethyl)-5-(6-((5,6-dimethyl-1H-benzo[d][1,2,3]triazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0297]

[0298] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.14 (d, J=2.3Hz, 1H), 845 (dd, J=8.2, 2.3Hz, 1H), 7.84 (s, 1H), 7.59 (s, 1H), 7. 57 (t, J=51.3Hz, 1H), 7.46 (d, J=8.4Hz, 1H), 6.18 (s, 2H), 2.37 (d, J=4.3Hz, 6H); MS (ESI, m / z): 357.24[M+1] + .

[0299] Example 60: 2-(6-((5,6-dichloro-2-methyl-1H-benzo[d]imidazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0300]

[0301] Yellow oily substance; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.34 (dd, J=2.2, 0.8Hz, 1H), 8.38 (dd, J=8.2, 2.2Hz, 1H), 7.84 (s, 1H), 7.36 (s, 1 H), 7.09-7.05 (m, 1H), 6.96 (t, J=51.6Hz, 1H), 5.50 (s, 2H), 2.67 (s, 3H); MS (ESI, m / z): 410.23 and 412.23[M+1] + .

[0302] Example 61: 2-(Difluoromethyl)-5-(6-((5,6-dimethyl-1H-benzo[d]imidazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0303]

[0304] Brown solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.36 (d, J=2.1Hz, 1H), 8.32 (dd, J=8.2, 2.2Hz, 1H), 8.07 (s, 1H), 7.65 (s, 1H), 7 .09-7.05 (m, 2H), 6.96 (t, J=51.6Hz, 1H), 5.59 (s, 2H), 2.40 (s, 3H), 2.36 (s, 3H); MS (ESI, m / z): 356.26[M+1] + .

[0305] Example 62 2-(6-((6-bromo-1H-benzo[d]imidazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole and Example 63: 2-(6-((5-bromo-1H-benzo[d]imidazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0306]

[0307] Two enriched fractions were obtained. Fraction 1: yellow oil; mixture of two regioisomers (distribution, first eluting compound: second eluting compound is 37:63); MS (ESI, m / z): 406.17 and 408.17 [M+1] + , the first eluting compound, and 406.17 and 408.17 [M+1] + , the second eluting compound.

[0308] Fraction 2: yellow oil; mixture of two regioisomers (distribution, first eluting compound: second eluting compound is 62:38); MS (ESI, m / z): 406.17 and 408.17 [M+1] + , the first eluting compound, and 406.17 and 408.17 [M+1] + , the second eluting compound.

[0309] Examples 57 and 58 can be separated by standard methods in the art, such as by silica gel column chromatography, however, they are presented herein as their enriched mixtures because this is the way they were tested in the bioassays mentioned below.

[0310] Example 64: 2-(6-((5-bromo-1H-benzo[d][1,2,3]triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0311]

[0312] Yellow oily substance; 1H NMR (δppm, 400MHz, CDCl3-d) 9.33 (d, J=2.0Hz, 1H), 8.38 (dd, J=8.2, 2.2Hz, 1H), 8.28 (dd, J=1.7, 0.7Hz, 1H), 7.6 0 (dd, J=8.8, 1.6Hz, 1H), 7.49 (dd, J=8.7, 0.7Hz, 1H), 7.33 (d, J=8.2Hz, 1H), 6.95 (t, J=51.6Hz, 1H), 6.07 (s, 2H),

[0313] Regiochemistry confirmed by nOe enhancement between protons at 6.07 ppm and protons at 7.33 ppm and 7.49 ppm; MS (ESI, m / z): 407.18 and 409.18 [M+1] + .

[0314] Example 65: 2-(6-((6-bromo-1H-benzo[d][1,2,3]triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0315]

[0316] Castor-colored oily substance; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.35 (s, 1H), 8.39 (dd, J=8.2, 2, 1Hz, 1H), 7.99 (d, J=8.8Hz, 1H), 7.79 (d, J=1, 8Hz, 1H), 7.52 (dd, J=8.8, 1.6Hz, 1H), 7.34 (d, J=8.2Hz, 1H), 6.95 (t, J=51.6Hz, 1H), 6.05 (s, 2H),

[0317] Regiochemistry confirmed by nOe enhancement between protons at 6.05 ppm and protons at 7.34 ppm and 7.79 ppm; MS (ESI, m / z): 407.18 and 409.18 [M+1] + .

[0318] Example 66: 2-(6-((5-bromo-2H-benzo[d][1,2,3]triazol-2-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0319]

[0320] Yellow oily substance; 1H NMR (δppm, 400MHz, CDCl3-d) 9.34 (d, J=2.1Hz, 1H), 8.40 (dd, J=8.2, 2.2Hz, 1H), 8.11 (d, J=1.7Hz, 1H), 7.81 (d d, J=9.0, 0.8Hz, 1H), 7.53 (dd, J=9.1, 1.7Hz, 1H), 7.31 (d, J=8.2Hz, 1H), 6.95 (t, J=51.7Hz, 1H), 6.15 (s, 2H),

[0321] Regiochemistry confirmed by nOe enhancement between protons at 6.15 ppm and 7.31 ppm only; MS (ESI, m / z): 407.18 and 409.18 [M+1] + .

[0322] B) Some examples of synthesis according to method B

[0323] The compound of formula (I) was synthesized by applying the following synthetic scheme:

[0324]

[0325] N-bromosuccinimide (NBS) (15.6mmol, 2.37g) and azobisisobutyronitrile (AIBN) (1.56mmol, 0.256g) were added to a solution of the corresponding alkylaryl compound (15.6mmol) in acetonitrile. The reaction mixture was refluxed for 2 hours and azobisisobutyronitrile (0.78mmol, 0.128g) was added again. After refluxing for one hour, the mixture was stirred at room temperature for 16 hours. Then, the solvent was evaporated under reduced pressure, and the crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain a bromide compound.

[0326] When W, X, Y and Z are all CH

[0327]

[0328] Subsequently, NaN3 (4.7mmol, 0.305g), NH4Cl (4.7mmol, 0.251g) and LiCl (1.7mmol, 0.071g) were added to a solution of the corresponding bromide compound (1.0mmol) in N,N-dimethylformamide (DMF) at room temperature. The reaction mixture was stirred at 100°C and monitored by TLC until the reaction was complete. Ethyl acetate was then added, and the organic layer was washed with water, dried over sodium sulfate, filtered and evaporated under reduced pressure. The crude product thus obtained can be used without further purification.

[0329]

[0330] At room temperature, N,N-diisopropylethylamine (DIPEA) (2.8mmol, 0.5ml) was added to a solution of the corresponding alkyne (0.5mmol), azide (0.5mmol) and CuI (0.22mmol, 0.041g) in N,N-dimethylformamide. The reaction mixture was stirred and monitored by HPLC-MS. After the reaction was complete, ethyl acetate was added. Then, the organic layer was washed with NH3 / H2O (×2) and brine, dried with Na2SO4, filtered and evaporated under reduced pressure. The crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain the desired product.

[0331] When one or two of W, X, Y or Z are N (taking pyridine as an example)

[0332]

[0333] To the solution of corresponding bromide compound (1.0mmol) in N,N-dimethylformamide, add NaN 3.Reaction mixture is stirred at room temperature for 5 hours.Then, ethyl acetate is added, and the organic layer is washed with water and salt water, dried over sodium sulfate, filtered and evaporated under reduced pressure.The crude product thus obtained can be used without further purification.

[0334]

[0335] At room temperature, N,N-diisopropylethylamine (DIPEA) (2.8mmol, 0.5ml) was added to a solution of the corresponding alkyne (0.5mmol), azide (0.5mmol) and CuI (0.22mmol, 0.041g) in N,N-dimethylformamide. The reaction mixture was stirred and monitored by HPLC-MS. After the reaction was complete, ethyl acetate was added. Then, the organic layer was washed with NH3 / H2O (×2) and brine, dried with Na2SO4, filtered and evaporated under reduced pressure. The crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain the desired product.

[0336]

[0337] Subsequently, NaN (4.7 mmol, 0.305 g), NH4Cl (4.7 mmol, 0.251 g) and LiCl (1.7 mmol, 0.071 g) were added to a solution of the corresponding nitrile compound (1.0 mmol) in N,N-dimethylformamide at room temperature. The reaction mixture was stirred at 100 ° C and monitored by TLC until the reaction was complete. The crude product thus obtained can be used without further purification.

[0338]

[0339] At room temperature, difluoroacetic anhydride (DFAA) (20.0mmol, 2.5ml) is added to the crude reaction obtained in the previous step. The reaction mixture is stirred at 60°C (when one or two of W, X, Y or Z are N) or 100°C (when W, X, Y and Z are CH respectively). The reaction process is monitored by HPLC-MS. After the reaction is completed, water is added and the solution is extracted with ethyl acetate. The combined organic fractions are washed with water and brine, dried and evaporated under reduced pressure with Na2SO4. The crude product thus obtained is purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain the desired product with high purity (>90%).

[0340] Some representative examples prepared using this protocol are:

[0341] Example 27: 2-(Difluoromethyl)-5-(4-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0342]

[0343] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 872 (s, 1H), 8.10 (d, J = 8.3Hz, 2H), 7.87 (d, J = 7.1Hz, 2H), 7.58 (d, J = 8.2Hz, 2H), 7 .56 (t, J=51.3Hz, 1H), 7.46 (dd, J=8.3, 7.0Hz, 2H), 7.38-7.33 (m, 1H), 5.82 (s, 2H); MS (ESI, m / z): 354.30[M+1] + .

[0344] Example 28: 1-(4-(5-(difluoromethyl)-1,3,4- oxadiazole-2-yl)benzyl)-1H-1,2,3-triazole-4-carboxylic acid methyl ester

[0345]

[0346] White solid; 1H NMR (δppm, 400MHz, DMSO-d6) 8.96 (s, 1H), 788 (d, J=8.3Hz, 2H), 7.56 (t, J=52.6Hz , 1H), 7.50 (d, J=8.3Hz, 2H), 5.80 (s, 2H), 3.84 (s, 3H); MS (ESI, m / z): 336.26[M+1] + .

[0347] Example 29: 2-(4-((4-(4-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0348]

[0349] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.77 (s, 1H), 8.10 (d, J = 8.3Hz, 2H), 790 (d, J = 8.6Hz, 2H), 758 (d, J = 8.2Hz , 2H), 7.56 (t, J=51.3Hz, 1H), 7.53 (d, d=8.6Hz, 2H), 5.82 (s, 2H); MS (ESI, m / z): 388.24 and 390.27[M+1] + .

[0350] Example 30: 2-(Difluoromethyl)-5-(4-((4-(4-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0351]

[0352] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.90 (s, 1H), 8.12-8.09 (m, 4H), 7.83 (d, J=8.2Hz, 2H), 7 .60 (d, J=83Hz, 2H), 7.56 (t, J=51.3Hz, 1H), 5.85 (s, 2H); MS (ESI, m / z): 422.31[M+1] + .

[0353] Example 31: 2-(4-((4-(tert-butyl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0354]

[0355] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.09 (d, J=8.3Hz, 2H), 7.99 (s, 1H), 7.56 (t, J=51.4Hz , 1H), 7.54 (d, J=8.3Hz, 2H), 5.68 (s, 2H), 1.28 (s, 9H); MS (ESI, m / z): 334.02[M+1] + .

[0356] Example 32: 2-(4-((4-cyclohexyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0357]

[0358] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.08 (d, J=8.3Hz, 2H), 7.97 (s, 1H), 7.56 (t, J=51.4Hz, 1H), 7.51 (d, J=8.3Hz, 2H), 5.68 (s, 2H), 2.72-2. 63 (m, 1H), 2.01-1.89 (m, 2H), 1.76-1.72 (m, 2H), 1.75-1.66 (m, 1H), 1.43-1.30 (m, 4H), 1.27-1.16 (m, 1H); MS (ESI, m / z): 360.57[M+1] + .

[0359] Example 33: 2-(Difluoromethyl)-5-(4-((4-(pyridin-4-yl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0360]

[0361] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.95 (s, 1H), 8.65 (d, J=5.8Hz, 2H), 8.11 (d, J=8.3Hz, 2H), 7.84 (d, J= 6.1Hz, 2H), 7.59 (d, J=8.2Hz, 2H), 7.56 (t, J=51.3Hz, 1H), 5.86 (s, 2H); MS (ESI, m / z): 355.00[M+1] + .

[0362] Example 34: 2-(Difluoromethyl)-5-(4-((4-(pyridin-3-yl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0363]

[0364] Yellow solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.08 (s, 1H), 8.85 (s, 1H), 8.56 (d, J=4.8Hz, 1H), 8.24 (dt, J=7.9, 2.0Hz, 1H), 8.11 (d, J=8.3H z, 2H), 7.59 (d, J=8.3Hz, 2H), 7.56 (t, J=51.3Hz, 1H), 7.50 (dd, J=8.0, 4.8Hz, 1H), 5.85 (s, 2H); MS (ESI, m / z): 355.25[M+1] + .

[0365] Example 35: 2-(Difluoromethyl)-5-(4-((4-(thiophen-3-yl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0366]

[0367] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.56 (s, 1H), 8.10 (d, J=8.3Hz, 2H), 7.88 (dd, J=2.9, 1.2Hz, 1H), 7.66 (dd, J=5, 0, 2.9Hz, 1 H), 7.56 (t, J=51.4Hz, 1H), 7.55 (d, J=8.3Hz, 2H), 7.53 (dd, J=5.1, 1.3Hz, 1H), 5.80 (s, 2H); MS (ESI, m / z): 360.22[M+1] + .

[0368] Example 36: 2-(Difluoromethyl)-5-(4-((4-(thiophen-2-yl)-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0369]

[0370] White solid; 1H NMR (δppm, 400MHz, DMSO-d6) 8.63 (s, 1H), 8.10 (d, J=8.3Hz, 2H), 7.58-7.54 (m, 3H), 7.56 (t, J=51.5 Hz, 1H), 7.55 (d, J=1.2Hz, 1H), 7.46 (dd, J=3.6, 1.1Hz, 1H), 5.80 (s, 2H); MS (ESI, m / z): 360.22[M+1] + .

[0371] Example 37: 2-(Difluoromethyl)-5-(4-(1-(4-phenyl-1H-1,2,3-triazol-1-yl)ethyl)phenyl)-1,3,4- Oxadiazole

[0372]

[0373] White solid; 1 H NMR (400MHz, DMSO-d6) δ8.84 (s, 1H), 8.09 (d, J = 8.4Hz, 2H), 7.88 (d, J = 7.1Hz, 2H), 7.60 (d, J = 8.4Hz, 2H), 7.56 (t, J = 51.4H z, 1H), 7.46 (t, J=7.6Hz, 2H), 7.38-7.33 (m, 1H), 6.16 (q, J=7.1Hz, 1H), 1.99 (d, J=7.1Hz, 3H); MS (ESI, m / z): 368.29[M+1] + .

[0374] Example 38: 2-(Difluoromethyl)-5-(4-((4,5-diphenyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0375]

[0376] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 8.08-8.01 (m, 2H), 7.62-7.57 (m, 2H), 7.56-7.50 (m, 2H), 7.49-7.43 (m, 2H), 7.33-7.2 7 (m, 2H), 7.23 (d, J=8.2Hz, 2H), 7.20-7.16 (m, 2H), 6.93 (t, J=51.7Hz, 1H), 5.53 (s, 2H); MS (ESI, m / z): 430.33[M+1] + .

[0377] Example 39: 2-(Difluoromethyl)-5-(4-((5-methyl-4-phenyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0378]

[0379] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d)8.18-8.12(m, 2H), 7.75-7.72(m, 2H), 7.51-7.46 (m, 2H), 7.41-7.37 (m, 3H), 6.94 (t, J=51.7Hz, 1H), 5.68 (s, 2H), 2.40 (s, 3H),

[0380] Regiochemistry confirmed by nOe enhancement between protons at 5.68 ppm and protons at 2.40 ppm and 7.41 ppm; MS (ESI, m / z): 368.27 [M+1] + .

[0381] Example 40: 2-(Difluoromethyl)-5-(4-((4-methyl-5-phenyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1,3,4- Oxadiazole

[0382]

[0383] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 806-8.02 (m, 2H), 7.49-7.45 (m, 3H), 7.22 (d, J=8.2Hz, 2H), 7.16 (dd , J=7.4, 2.2Hz, 2H), 6.93 (t, J=51.7Hz, 1H), 5.55 (s, 2H), 2.35 (s, 3H); MS (ESI, m / z): 368.27[M+1] + .

[0384] Example 41: 2-(Difluoromethyl)-5-(6-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0385]

[0386] White solid; 1H NMR (δppm, 400MHz, DMSO-d6) 9.21 (d, J=2.2Hz, 1H), 8.74 (s, 1H), 8.50 (dd, J=8.2, 2.3Hz, 1H), 7.89 (dd, J=8.3, 1.3Hz, 1H), 7.59 (t, J=51.4Hz, 1H), 7.58 (d, J=8.5Hz, 2H), 7.47 (t, J=7.6Hz, 2H), 7.36 (t, J=7.4Hz, 1H), 5.94 (s, 2H); MS (ESI, m / z): 355.25[M+1] + .

[0387] Intermediates :

[0388] 6-(Bromomethyl)nicotinonitrile

[0389]

[0390] MS (ESI, m / z): 196.99 [M+1] + .

[0391] 6-(Azidomethyl)nicotinonitrile

[0392]

[0393] MS (ESI, m / z): 160.02 [M+1] + .

[0394] 6-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)nicotinonitrile has the following structure:

[0395]

[0396] MS (ESI, m / z): 262.20 [M+1] + .

[0397] 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)-5-(1H-tetrazol-5-yl)pyridine

[0398]

[0399] MS (ESI, m / z): 305.23 [M+1] + .

[0400] Example 42: 2-(Difluoromethyl)-5-(5-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridin-2-yl)-1,3,4- Oxadiazole

[0401]

[0402] Yellow oily substance; 1 H NMR (δppm, 400MHz, DMSO-d6) 8.90 (d, J=2.1Hz, 1H), 8.75 (s, 1H), 8.30 (d, J=8.1Hz, 1H), 8.02 (dd, J=8.2, 2.2Hz, 1H), 7. 88-7.85 (m, 2H), 7.60 (t, J=51.3Hz, 1H), 7.49-7.44 (m, 2H), 7.38-7.33 (m, 1H), 5.88 (s, 2H); MS (ESI, m / z): 355.25[M+1] + .

[0403] Example 43: 2-(6-((4-(4-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0404]

[0405] Yellow solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.20 (d, J=2.2Hz, 1H), 8.78 (s, 1H), 8.50 (dd, J=8.2, 2.3Hz, 1H), 7.92 (d, J=8.5Hz, 2H), 7 .59 (t, J=51.3Hz, 1H), 7.58 (d, J=8.1Hz, 1H), 7.54 (d, J=8.5Hz, 2H), 5.95 (s, 2H); MS (ESI, m / z): 389.25 and 391.21[M+1] + .

[0406] Example 44: 2-(6-((4-(2-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0407]

[0408] Yellow solid; 1H NMR (δppm, 400MHz, DMSO-d6) 9.21 (s, 1H), 8.87 (s, 1H), 8.50 (dd, J=8.3, 2.3Hz, 1H), 8.14 (d, J=7. 8Hz, 1H), 7.66-7.54(m, 3H), 7.52-7.38(m, 2H), 6.00(s, 2H); MS (ESI, m / z): 389.25 and 391.25[M+1] + .

[0409] Example 45: 2-(6-((4-(3-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0410]

[0411] Yellow solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.21 (d, J=2.2Hz, 1H), 8.83 (s, 1H), 8.51 (dd, J=8.2, 2.3Hz, 1H), 7.95 (t, J=1.9Hz, 1H), 7.89-7. 85 (m, 1H), 7.61 (d, J=8.7Hz, 1H), 7.59 (t, J=51.1Hz, 1H), 7.53-7.40 (m, 2H), 5.95 (s, 2H); MS (ESI, m / z): 389.22 and 391.25[M+1] + .

[0412] Example 46: 2-(6-((4-(3,4-dichlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0413]

[0414] Yellow solid; 1H NMR (δppm, 400MHz, DMSO-d6) 9.20 (d, J=2.2Hz, 1H), 8.87 (s, 1H), 8.51 (dd, J=8.2, 2.3Hz, 1H), 8.15 (d, J=2.0Hz, 1H), 7.90 (dd, J=8.4 , 2.0Hz, 1H), 7.75 (d, J=8.4Hz, 1H), 7.62 (d, J=8.2Hz, 1H), 7.59 (t, J=51.2Hz, 1H), 5.96 (s, 2H); MS (ESI, m / z): 423.22 and 425.22[M+1] + .

[0415] Example 47: 2-(6-((4-(3,5-dichlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0416]

[0417] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.21 (dd, J=2.3, 0.8Hz, 1H), 8.91 (s, 1H), 8.51 (dd, J=8.2, 2.3Hz, 1H), 7.96 (d, J=2.0Hz, 2H), 7 .64 (dd, J=8.2, 0.9Hz, 1H), 7.61 (t, J=1.9Hz, 1H), 7.59 (t, J=51.2Hz, 1H), 5.96 (s, 2H).MS (ESI, m / z): 423.26 and 425.28[M+1] + .

[0418] Example 48: 2-(Difluoromethyl)-5-(6-((4-(2-fluorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0419]

[0420] Yellow solid; 1H NMR (δppm, 400MHz, DMSO-d6) 9.20 (dd, J=2.3, 0.8Hz, 1H), 8.64 (d, J=3.8Hz, 1H), 8.49 (dd, J=8.2, 2.3Hz, 1H), 8.18 (td, J=7 .6, 1.7Hz, 1H), 7.65 (t, J=51.3Hz, 1H), 7.56 (d, J=8.2Hz, 1H), 7.45-7.33 (m, 3H), 5.99 (s, 2H); MS (ESI, m / z): 373.21[M+1] + .

[0421] Example 49: 2-(Difluoromethyl)-5-(6-((4-(2,6-difluorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0422]

[0423] Brown solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 9.21 (d, J=2.2Hz, 1H), 8.66 (t, J=1.5Hz, 1H), 8.51 (dd, J=8.2, 2.3Hz, 1H), 7.59 (d, J=8.2Hz, 1 H),), 7.59 (t, J=51.2Hz, 1H), 7.52 (tt, J=8.5, 6.4Hz, 1H), 7.28 (t, J=8.4Hz, 2H), 6.00 (s, 2H); MS (ESI, m / z): 391.28[M+1] + .

[0424] Example 50: 2-(6-((4-(3-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0425]

[0426] White solid; 1H NMR (δppm, 400MHz, DMSO-d6) 9.21 (d, J=2.2Hz, 1H), 8.75 (s, 1H), 8.50 (dd, J=8.2, 2.3Hz, 1H), 7.59 (t, J=51.4Hz, 1H), 7.58 (d, J=9.0Hz, 1H), 7.48 (t, J= 1.3Hz, 1H), 7.46 (dt, J=3.4, 1.8Hz, 1H), 7.38 (t, J=7.9Hz, 1H), 6.93 (ddd, J =8.2, 2.6, 1.1Hz, 1H), 5.94 (s, 2H), 3.82 (s, 3H); MS (ESI, m / z): 385.33[M+1] + .

[0427] Example 56: 2-(Difluoromethyl)-5-(6-((4-(3,5-difluorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0428]

[0429] White solid; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.20 (d, J=2.3Hz, 1H), 8.86 (s, 1H), 8.51 (dd, J=8.2, 2.3Hz, 1H), 7.65 -7.61 (m, 3H), 7.59 (t, J=51.3Hz, 1H), 7.30-7.20 (m, 1H), 5.97 (s, 2H); MS (ESI, m / z): 391.25[M+1] + .

[0430] Example 57: 2-(Difluoromethyl)-5-(6-((4-(3,4,5-trifluorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-1,3,4- Oxadiazole

[0431]

[0432] White solid; 1H NMR (δppm, 400MHz, CDCl3-d) 9.20 (d, J=2.1Hz, 1H), 8.82 (s, 1H), 8.51 (dd, J=8.2, 2.3Hz, 1H), 7.85 (dd, J =9.0, 6.7Hz, 2H), 7.63 (d, J = 8.2Hz, 1H), 7.59 (t, J = 51.2Hz, 1H), 5.97 (s, 2H); MS (ESI, m / z): 409.25[M+1] + .

[0433] C) Some examples of synthesis according to method C of the present invention

[0434] The compound of formula (I) was synthesized by applying the following synthetic scheme:

[0435]

[0436] CuI (2.5 mmol, 0.500 g) was dissolved in ammonium hydroxide. While stirring, the corresponding arylacetylene was added dropwise. After 15 minutes, the formed yellow precipitate was filtered and washed with water, EtOH and Et2O.

[0437] When W, X, Y and Z are all CH

[0438]

[0439] To a solution of the corresponding copper(I) aryl acetylide (0.5 mmol) and the corresponding azide (synthesized as described in method B; 0.6 mmol) in CH2Cl2 (1 ml) was added N-chlorosuccinimide (0.6 mmol, 0.080 g). The mixture was stirred at room temperature and monitored by HPLC-MS. After completion of the reaction, dichloromethane was evaporated under reduced pressure and the crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to give the desired product.

[0440] When one or two of W, X, Y or Z are N (taking pyridine as an example)

[0441]

[0442] To a solution of the corresponding copper(I) aryl acetylide (0.5 mmol) and the corresponding azide derivative (synthesized as described in method B; 0.6 mmol) in CH2Cl2 (1 ml) was added N-chlorosuccinimide (0.6 mmol, 0.080 g). The mixture was stirred at room temperature and monitored by HPLC-MS. After completion of the reaction, dichloromethane was evaporated under reduced pressure and the crude product thus obtained was purified by flash chromatography (silica gel, ethyl acetate / hexane) to give the desired product.

[0443]

[0444] Subsequently, NaN (4.7 mmol, 0.305 g), NH Cl (4.7 mmol, 0.251 g) and LiCl (1.7 mmol, 0.071 g) were added to a solution of the corresponding nitrile derivative (1.0 mmol) in N,N-dimethylformamide at room temperature. The reaction mixture was stirred at 100 ° C and monitored by TLC until the reaction was complete. The crude product thus obtained can be used without further purification.

[0445]

[0446] At room temperature, add DFAA (20.0mmol, 2.5ml) to the crude reaction obtained in the previous step. The reaction mixture is stirred at 60°C (when W=N) or 100°C (when W=C). Monitor the reaction process by HPLC-MS. After the reaction is completed, add water and extract the solution with ethyl acetate. The combined organic fractions are washed with water and brine, dried with Na2SO4 and evaporated under reduced pressure. The crude product thus obtained is purified by flash chromatography (silica gel, ethyl acetate / hexane) to obtain the desired product of high purity (>90%).

[0447] Some representative examples prepared using this protocol are:

[0448] Example 51: 2-(4-((5-chloro-4-phenyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0449]

[0450] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 1H NMR (400 MHz, DMSO-d6) 8.11 (d, J = 8.3 Hz, 2H), 7.95-7.91 (m, 2H), 7.56 (t, J = 51.4 Hz, 1H), 7.56-7.52 (m, 4H), 7.48-7.44 (m, 1H), 5.88 (s, 2H); MS (ESI, m / z): 388.20 and 390.20 [M+1] + .

[0451] Intermediates :

[0452] (Phenylethynyl) copper

[0453]

[0454] MS (ESI, m / z): 388.20 [M+1] + .

[0455] (5-(4-(Azidomethyl)phenyl)-1H-tetrazolyl

[0456]

[0457] MS (ESI, m / z): 202.20 [M+1] + .

[0458] 5-(4-((5-chloro-4-phenyl-1H-1,2,3-triazol-1-yl)methyl)phenyl)-1H-tetrazolyl

[0459]

[0460] MS (ESI, m / z): 338.19 and 340.18 [M+1] + .

[0461] Example 52: 2-(6-((5-chloro-4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole, having the following structural formula:

[0462]

[0463] White solid; 1 H NMR (δppm, 400MHz, DMSO-d6) 1H NMR (400MHz, DMSO-d6) 9.18 (d, J = 2.3Hz, 1H), 8.52 (dd, J = 8.2, 2.3Hz, 1H), 7.99-7.92 (m, 2H), 7.68 (d, J = 8.3Hz, 1H) , 7.59 (d, J=51.3Hz, 1H), 7.55 (t, J=7.7Hz, 2H), 7.48-7.44 (m, 1H), 6.02 (s, 2H); MS (ESI, m / z): 389.22 and 391.21[M+1] + .

[0464] Example 53: 2-(6-((5-chloro-4-(2-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0465]

[0466] Yellow oily substance; 1 H NMR (δppm, 400MHz, CDCl3-d) 9.37 (d, J=2.1Hz, 1H), 8.46 (dd, J=8.3, 2.2Hz, 1H), 7.58-7.54 (m, 2H), 7.45-7. 41 (m, 2H, 7.32 (d, J=8.5Hz, 1H), 6.97 (t, J=51.6Hz, 1H), 5.89 (s, 2H); MS (ESI, m / z): 423.19 and 425.18[M+1]+.

[0467] Example 54: 2-(6-((5-chloro-4-(3-chlorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0468]

[0469] Yellow oily substance; 1 H NMR (δ ppm, 400 MHz, CDCl a -d) 9.35 (d, J=2.2Hz, 1H), 8.45 (dd, J=8.2, 2.2Hz, 1H), 8.05 (t, J=1.9Hz, 1H), 7.94 (dt, J=7.5, 1.6Hz, 1H), 7.4 9-7.39 (m, 2H), 7.34 (d, J=8.2Hz, 1H), 6.97 (t, J=51.6Hz, 1H), 5.87 (s, 2H); MS (ESI, m / z): 423.19 and 425.22[M+1]+ .

[0470] Example 67: Preparation of 2-(6-((5-chloro-4-(2-fluorophenyl)-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole, the structural formula is as follows:

[0471]

[0472] This compound was prepared as described in Method C. Yellow oil;

[0473] 1 H NMR (δppm, 400MHz, CDCl3-d) 9.37 (s, 1H), 8.46 (d, J=8.1Hz, 1H), 7.76 (td, J=7.5, 1.8Hz, 1H), 7.47 (tdd, J=7.3, 6.1, 1.6Hz, 1H) , 7.33-7.27 (m, 2H), 7.23 (ddd, J=9.7, 8.3, 1.1Hz, 1H), 6.97 (t, J=51.6Hz, 1H), 5.88 (s, 2H); MS (ESI, m / z): 407.22 and 409.22[M+1] +

[0474] The compounds obtained by any of the above methods can be further converted into other compounds of the present invention. A representative example is shown below.

[0475] Example 55: 2-(6-(chloro(4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridin-3-yl)-5-(difluoromethyl)-1,3,4- Oxadiazole

[0476]

[0477] To a solution of Example 39 (0.05 mmol) in N,N-dimethylformamide (0.3 ml) was added N-chlorosuccinimide (0.08 mmol, 0.015 g). The resulting mixture was refluxed for 16 hours. The crude reaction solution was then evaporated to dryness under reduced pressure and purified by flash chromatography (silica gel, ethyl acetate / hexane) to give the desired product.

[0478] Yellow oily substance; 1H NMR (δppm, 400MHz, CDCl3-d) 9.43 (d, J=2.2Hz, 1H), 8.58 (dd, J=8.2, 2.2Hz, 1H), 8.42 (s, 1H), 7.94-7.88 (m, 3H), 7.6 9 (s, 1H), 7.48 (dd, J=8.2, 6.7Hz, 2H), 7.44-7.37 (m, 1H), 6.99 (t, J=51.6Hz, 1H); MS (ESI, m / z): 389.25 and 391.25[M+1] + .

[0479] Biological activities of the compounds of the present invention

[0480] All enzymatic reactions were carried out in duplicate at room temperature for 17 hours in 50 μL mixtures containing HDAC assay buffer (50mM Tris-HCl, pH 7.4, 137mM NaCl, 2.7mM KCl, 0.05% Tween 20, 5 μg BSA), HDAC substrate, HDAC enzyme and test compound. Compound dilutions were prepared with 100% DMSO, which was 100 times higher than the final concentration of the compound, and 300 nL dilutions were added to 30 μL reactants by an echo acoustic dispenser (Echo acoustic dispenser) so that the final concentration of DMSO in all reactions was 1%. After the enzymatic reaction, the reaction was stopped by adding 5 μl 10 μM known inhibitor solutions. The fluorescent signals of substrate and product were measured in EZ Reader II equipment by microfluidics mobility assay. The percentage of substrate converted into product was calculated based on peak area by equipment software.

[0481] The percentage of conversion data is analyzed using computer software Graphpad Prism. In the absence of compound, the conversion (Ct) in each data set is defined as 100% activity. In the absence of HDAC, the conversion (Cb) in each data set is defined as 0% activity. The percentage activity in the presence of each compound is calculated according to the following equation: % inhibition=(Ct-C) / (Ct-Cb), wherein C=conversion percentage in the presence of compound.

[0482] The % inhibition values ​​were then plotted against a range of compound concentrations using nonlinear regression analysis of the sigmoidal dose-response curves generated by the equation Y = B + (TB) / 1 + 10 ((LogEC50-X) x Hill Slope), where Y = percent inhibition, B = minimum percent inhibition, T = maximum percent inhibition, X = logarithm of compound, and Hill Slope = slope factor or Hill Coefficient.50 Values ​​were determined from the concentrations that elicited half-maximal percent activity.

[0483] hHDAC1 inhibition protocol:

[0484] The buffer used in the hHDAC1 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and HDAC1 (BPS Bioscience 50010) enzyme 5nM were added to a 384-well microplate (Geriner 784209) and incubated for 3 hours at room temperature. Then acetylated peptide A (PerkinElmer CLS960006) 2μM was added and incubated for 1 hour at room temperature. Finally, 1.4μM LBH589 (ReactionBiology Corp EPI009B) was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC1, LBH-589 (Reaction Biology Corp EPl009B) IC50 1 nM, J Med Chem 2016, 59, 1455-1470.

[0485] hHDAC2 inhibition protocol:

[0486] The buffer used in the hHDAC2 inhibition assay was: Hepes 50mM, KC1 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. The study compound and HDAC2 (BPS Bioscience 50002) enzyme 12nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 3 hours. Then acetylated peptide A (PerkinElmer CLS960006) 1μM was added and incubated at room temperature for 1 hour. Finally, LBH589 (Reaction BiologyCorp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. hHDAC2, LBH-589 (Reaction Biology Corp EPI009B) IC50<3nM, Gale et al, Application note Perkin Elmer.

[0487] hHDAC3 inhibition protocol:

[0488] The buffer used in the hHDAC3 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and HDAC3 (BPS Bioscience 50003) enzyme 5nM were added to a 384-well microplate (Gerinet 784209) and incubated for 3 hours at room temperature. Acetylated peptide A (PerkinElmer CLS960006) 2μM was then added and incubated for 1 hour at room temperature. Finally, LBH589 (Reaction BiologyCorp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC3, LBH-589 (Reaction Biology Corp EPI009B) IC50 2 nM, Cancer Lett 2009; 280: 233-241.

[0489] hHDAC4 inhibition protocol:

[0490] The buffer used in the hHDAC4 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and HDAC4 (BPS Bioscience 50004) enzyme 0.5nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 5 minutes. Acetylated peptide B (PerkinElmer CLS960007) 1μM was then added and incubated at room temperature for 1 hour. Finally, LBH589 (Reaction BiologyCorp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC4, LBH-589 (Reaction Biology Corp EP1009B), IC50 65 nM, Gale et al., Apphcatlon note PerkinElmer.

[0491] hHDAC5 inhibition protocol:

[0492] The buffer used in the hHDAC5 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and HDAC5 (BPS Bioscience 50005) enzyme 0.75nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 5 minutes. Acetylated peptide B (PerkinElmer CLS960007) 2μM was then added and incubated at room temperature for 1 hour. Finally, LBH589 (Reaction BiologyCorp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC5, LBH-589 (Reaction Biology Corp EPI009B), IC50 160 nM, Nat. Chem. Biol. 6, 238-243 (2010).

[0493] HDAC6 inhibition regimen:

[0494] The buffer used in the hHDAC6 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. The study compound and hHDAC6 (BPS Bioscience 50006) enzyme 1.20nM were added to a 384-well microplate (Greiner 784209) and incubated at room temperature for 5 minutes. Then acetylated peptide A (Perkin Elmer CLS960006) 2μM was added and incubated at room temperature for 1 hour. Finally, LBH589 (ReactionBiology Corp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC6, LBH589 (Reaction Biology Corp EPI009B), IC50 2.0 nM, Gale et al., PerkinElmer Application note.

[0495] hHDAC7 inhibition protocol:

[0496] The buffer used in the hHDAC7 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and HDAC7 (BPS Bioscience 50007) enzyme 5nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 5 minutes. Then acetylated peptide B (PerkinElmer CLS960007) 2μM was added and incubated at room temperature for 1 hour. Finally, LBH589 (Reaction BiologyCorp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC7, LBH-589 (Reaction Biology Corp EPl 009B), IC50 760 nM, Gale et al, Application note Perkin Elmer.

[0497] hHDAC8 inhibition protocol:

[0498] The buffer used in the hHDAC8 inhibition assay was: Hepes 50mM, KC1 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and HDAC8 (BPS Bioscience 50008) enzyme 1nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 5 minutes. Acetylated peptide B (PerkinElmer CLS960007) 2μM was then added and incubated at room temperature for 1 hour. Finally, LBH589 (Reaction BiologyCorp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC8, Trichostatin A (Reaction Biology Corp. EPI009F), IC50 90 nM, Bradner, JE et al. Nat. Chem. Biol. 6, 238-243 (2010).

[0499] hHDAC9 inhibition protocol:

[0500] The buffer used in the hHDAC9 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. The study compound and HDAC9 (BPS Bioscience 50009) enzyme 2nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 5 minutes. Then acetylated peptide B (PerkinElmer CLS960007) 2μM was added and incubated at room temperature for 1 hour. Finally, LBH589 (Reaction BiologyCorpEPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip 3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC9, LBH-589 (Reaction Biology Corp EPI009B), IC50 390 nM, Gale et al., Application note Perkin Elmer.

[0501] HDAC10 inhibition protocol:

[0502] The buffer used in the hHDAC10 inhibition assay was: Hepes 50mM, KCl 100mM, Tween 200.001%, BSA 0.01%; pH = 7.4. Study compounds and hHDAC10 (BPS Bioscience 50010) enzyme 10nM were added to a 384-well microplate (Geriner 784209) and incubated at room temperature for 60 minutes. Acetylated peptide A (Perkin Elmer CLS960006) 6μM was then added and incubated at room temperature for 24 hours. Finally, LBH589 (ReactionBiology Corp EPI009B) 1.4μM was added to stop the reaction. The reaction was measured in a Caliper EzReader LabChip3000 (Caliper, Hopkinton, MA) reader. Literature IC50 values ​​of reference compounds used to validate the assay: hHDAC10, SAHA (provided by Quimatryx), IC50 456 nM, Hanessian et al., ACSMed.Chem.Lett. 2010, 1, 2, 70-74.

[0503] The following HDAC6 inhibitory activities were observed for Examples 1 to 67

[0504]

[0505]

[0506] In addition, Examples (Ex.) 1 to 67 show high selectivity relative to other HDAC1-10 enzymes. Some representative selectivities are shown in the table below.

[0507] #imgpt188#

Claims

1. A compound of formula (I) or a salt thereof, in W, X, Y or Z is N, and the remaining ones of W, X, Y and Z are each CH; or each of W, X, Y and Z is CH; R1 is H; methyl; or halogen; and R2 is an aromatic heterocyclic ring, wherein the ring contains 1 to 4 nitrogen atoms and wherein one of these ring nitrogen atoms which is an R2 group forms a bond to the rest of formula (I), the aromatic heterocyclic ring being selected from a 5-membered monocyclic heteroaryl ring or a 9-membered bicyclic heteroaryl ring, wherein R2 is unsubstituted or substituted at one or more available positions with a substituent selected from the following: - C1-C6 alkyl and C1-C6 halogenated alkyl; -halogen; -phenyl and phenyl substituted by C1-C6 alkyl, C1-C6 alkoxy, C1-C6 halogenated alkyl, or halogen; -=O、-C(=O)R a OR -C(=O)OR a , where R a is a C1-C6 alkyl group or a C1-C6 halogenated alkyl group; and -pyridyl; -thienyl.

2. The compound of claim 1, wherein X is N and the remaining terms of W, X, Y and Z are each CH.

3. The compound of claim 1, wherein each of W, X, Y and Z is CH.

4. The compound according to claim 1, wherein R1 is H.

5. The compound according to claim 1, wherein R2 is a 5-membered monocyclic heteroaryl ring.

6. The compound according to claim 5, wherein R2 is a triazolyl or imidazolyl ring.

7. The compound of claim 1, wherein R2 is a 9-membered bicyclic heteroaryl ring.

8. The compound according to claim 7, wherein R2 is a benzotriazolyl or benzimidazolyl ring.

9. A compound selected from: or a salt thereof.

10. A process for preparing a compound as defined in any one of claims 1 to 9, comprising reacting a tetrazole of formula (II) with difluoroacetic anhydride wherein W, X, Y, Z, R1, and R2 are as defined in any one of claims 1 to 9.

11. A pharmaceutical composition comprising a compound as defined in any one of claims 1 to 9 or a salt thereof, and at least one pharmaceutically acceptable excipient.

12. Use of a compound or a salt thereof as defined in any one of claims 1 to 9 in the preparation of a medicament for treating or preventing an HDAC6-related disease or disorder, wherein the HDAC6-related disease or disorder is selected from the group consisting of cancer, inflammation, neurodegenerative disorders, autoimmune diseases, peripheral neuropathy, major depression, renal disease and transplant rejection.

13. The use according to claim 12, wherein the HDAC6-related disease or disorder is a central nervous system HDAC6-related disease or disorder, wherein the central nervous system HDAC6-related disease or disorder is Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, spinal muscular atrophy, Charcot-Marie-Tooth disease, multiple sclerosis or depression.

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