WO2019224743A1 - Oxadiazoles as fxr receptor antagonists - Google Patents

Abstract

The present invention relates to compounds of Formula (I) or pharmaceutically acceptable salts or solvates thereof: It further discloses a pharmaceutical composition comprising the compounds of Formula (I) and their uses, in particular to prevent and/or treat a disorder selected from the group consisting of gastrointestinal disorders, liver disorders, cardiovascular disorders, vascular disorders, pulmonary disorders, metabolic pathologies, infectious diseases, cancer, renal disorders, inflammatory disorders including immune-mediated, and neurological disorders.

Description

OXADIAZOLES AS FXR RECEPTOR ANTAGONISTS

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no. 102018000005598 filed on 22/05/2018, the entire disclosure of which is incorporated herein by reference .

FIELD OF THE INVENTION

The present invention relates to oxadiazole derivatives and their uses, in particular in the treatment and/or prevention of FXR mediated diseases.

BACKGROUND ART

Farnesoid X receptor (FXR, also known as BAR, NR1H4) is a ligand-dependent transcription factor and belongs to the super-family of nuclear hormone receptors.

Highly expressed in entero-hepatic tissues (liver and intestine) , FXR regulates bile acid homeostasis, lipoprotein, glucose metabolism, liver regeneration and cardiovascular disorders (Mangelsdorf, D. J. et al . Cell 1995, 83; 835; Forman, B. M. et al . Cell 1995, 81, 687;

Makishima, M. et al . Science 1999, 284, 1362; Parks, D. J. et al . Science 1999, 284, 1365; Wang, H. et al . Mol. Cell

1999, 3, 543; Kuipers, F. et al . Rev. Endocr. Metab. Disord. 2004, 5,319; Zhang et al . Proc. Natl. Acad. Sci. USA 2006, 103, 1006; Matsubara, T. et al . Mol. Cell. Endocrinol. 2013,

368, 17; Claudel, T. et al . Arterioscler . Thromb . Vase. Biol. 2005, 25, 2020) . Specific bile acids bind and activate FXR, the most potent being chenodeoxycholic acid (CDCA) , which is an endogenous ligand of FXR and the primary bile acid found in human bile.

In recent years, various potent and selective FXR agonists have been reported, belonging to steroidal and non steroidal chemical classes, such as 6-ECDCA, GW4064 and Fexaramine . Indeed, as the research field of FXR agonists expanded, several side effects result from advanced clinical trials with dis-regulation in serum lipids observed in patients with diabetes and liver steatosis (Fiorucci S. et al . Expert Opin Ther Targets 2014, 18, 1449-59) . In addition, FXR agonists interfere with the ability of constitutive androstane receptor in regulating MRP-4 transporter (Renga B. et al . Biochim Biophys Acta 2011, 3, 157-65) in hepatocytes and this effect worsens liver injury in obstructive cholestasis.

Recent studies reported that antagonizing the FXR activity could have potential effect on lowering the levels of total cholesterol, triglyceride and glucose pointing the attention on the potential application of the FXR antagonists in the treatment of metabolic dysregulation . In addition, recent findings raise the notion that FXR gene ablation protects from hepatocytes injury caused by bile duct ligation (BDL) affirming the utility of FXR antagonists in the treatment of some forms of cholestasis.

Few FXR antagonists have been described so far with very limited structural diversity. The main contribution resulted from target-oriented decodification of marine and terrestrial natural compounds, with the identification of several steroidal scaffolds with promising pharmacological properties. Among these, naturally occurring Glyco-b- muricholic acid (QbMOA) has been demonstrated as a novel strategy for treatment of obesity, NAFLD, and insulin resistance (W02015017813 ) . In the setting of nonsteroidal chemotypes, only isoxazole and pyrazole/pyrazolone have been identified as privileged scaffold in FXR antagonism (WO2015116856) . Therefore, structurally novel, nonsteroidal FXR antagonists represents an important direction in the field .

DISCLOSURE OF INVENTION

The object of the present invention is the identification of novel compounds that act as FXR antagonists .

Said object is achieved by the present invention, relative to selective FXR antagonists containing the 1,2,4- oxadiazole chemical scaffold of claim 1, to a pharmaceutical composition of claim 8, to the uses of claims 9 and 10. Preferred embodiments are set out within the dependent claims .

The following paragraphs provide definitions of the various chemical moieties of the compounds according to the invention and are intended to apply uniformly through-out the specification and claims unless an otherwise expressly set out definition provides a broader definition.

The term "alkyl", as used herein, refers to saturated aliphatic hydrocarbon groups. Such term includes straight (unbranched) chains or branched chains.

Non-limiting examples of alkyl groups according to the invention are, for example, methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso pentyl, n-hexyl and the like.

The term "pharmaceutically acceptable salts" refers to salts of the below identified compounds of Formula (I) that retain the desired biological activity and are accepted by regulatory authorities.

As used herein, the term "salt" refers to any salt of a compound according to the present invention prepared from an inorganic or organic acid or base and internally formed salts. Typically, such salts have a physiologically acceptable anion or cation.

Furthermore, the compounds of Formula (I) may form an acid addition salt or a salt with a base, depending on the kind of the substituents, and these salts are included in the present invention, as long as they are pharmaceutically acceptable salts.

Examples of such salts include, but are not restricted to acid addition salts formed with inorganic acids, salts formed with organic acids.

The compounds of formula (I) containing acidic protons may be converted into their therapeutically active, non toxic base addition salt forms, e.g. metal or amine salts, by treatment with appropriate organic and inorganic bases.

Physiologically or pharmaceutically acceptable salts are particularly suitable for medical applications because of their greater aqueous solubility relative to the parent compound .

Pharmaceutically acceptable salts may also be prepared from other salts including other pharmaceutically acceptable salts of the compounds of Formula (I) using conventional methods .

Those skilled in the art of organic chemistry will appreciate that many organic compounds can form complexes with solvents in which they are reacted or from which they are precipitated or crystallized. These complexes are known as "solvates". For example, a complex with water is known as a "hydrate". Solvates of the compounds of the invention are within the scope of the invention. The compounds of Formula (I) may readily be isolated in association with solvent molecules by crystallization or evaporation of an appropriate solvent to give the corresponding solvates.

The compounds of Formula (I) may be in crystalline form. In certain embodiments, the crystalline forms of the compounds of Formula (I) are polymorphs.

The subject invention also includes isotopically- labelled compounds, which are identical to those recited in Formula (I) and following, but differ on the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into the compounds of the invention and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, such as ²H, ³H, ³¹0, ¹³C, ¹⁴C, ¹⁵N, ¹⁷0, ¹⁸0.

Compounds of the present invention and pharmaceutically acceptable salts of said compounds that contain the aforementioned isotopes and/or other isotopes of other atoms are within the scope of the present invention. Isotopically- labelled compounds of the present invention, for example those into which radioactive isotopes such as ³H, ¹⁴C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, i.e. ³H, and carbon-14, i.e. ¹⁴C, isotopes are particularly preferred for their ease of preparation and detectability. ⁴¹C isotope is particularly useful in PET (Positron Emission Tomography) . Furthermore, substitution with heavier isotopes such as deuterium, i.e. ²H, can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically-labelled compounds of Formula (I) of this invention can generally be prepared by carrying out the procedures disclosed in the Schemes and/or in the Examples below, by replacing a non- isotopically-labelled reagent with a readily available isotopically-labelled reagent.

Certain groups/substituents included in the present invention may be present as isomers. Accordingly, in certain embodiments, the compounds of Formula (I) may have asymmetric carbon atoms or axial asymmetries in some cases and, correspondingly, they may exist in the form of optical isomers such as an (A) -form, an (S) -form, and the like. The present invention includes within the scope all such isomers, including racemates, enantiomers and mixtures thereof.

In particular, within the scope of the present invention are included all stereoisomeric forms, including enantiomers, diastereoisomers , and mixtures thereof, including racemates, and the general reference to the compounds of Formula (I) includes all the stereoisomeric forms, unless otherwise indicated.

In general, the compounds or salts of the invention should be interpreted as excluding those compounds (if any) which are so chemically unstable, either per se or in water, that they are clearly unsuitable for pharmaceutical use through all administration routes, whether oral, parenteral, or otherwise. Such compounds are known to the skilled chemist .

According to a first aspect of the invention, compounds of Formula ( I ) :

or pharmaceutically acceptable salts or solvates thereof are provided .

In the compounds of Formula (I) : Ai and A2 are selected from the group consisting of CH2 and NRi provided that Ai and A2 are not at the same time CH2 or NRi,

Ri is selected from CH₃ and (CH_2)2-4-R₂,

R2 is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R3 is selected from the group consisting of H and C1-4 alkyl ,

R₄ , R5, R6 , R7, Re , R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C_1-4 alkyl, halogen and OH.

n is selected from 1 and 2.

According to a first embodiment, n is 1. These compounds can have formula (la) :

wherein Ri, R₂ R₃, R₄, R5, R6, R₇, Rs, R₉ and Rio are as defined above .

According to a second embodiment, n is 2. These compounds can have formula (lb)

or formula (Ic)

wherein Ri, R₂ R3, R4, R5, R6, R₇, Rs, R9 and Rio are as defined above .

Preferably, Ri is (CH2)3-R2.

Preferably, R2 is COOR3.

Preferably, R₃ is a methyl group.

Preferably, each of R₄, R5, R6, R7, Rs, R9 and Rio is hydrogen .

According to a third embodiment of the invention, the compounds of Formula (I) can be selected from the group consisting of:

The compounds exemplified in this invention may be prepared from readily available starting materials using the following general methods and procedures for example exemplified in Michael B. Smith - March's Advanced Organic Chemistry: reactions, mechanisms, and structure - 7th Edition, John Wiley & Sons Inc., 2013.

It is well known to one of ordinary skill in the art that transformation of a chemical function into another may require that one or more reactive centers in the compound containing this function be protected in order to avoid undesired side reactions. Protection of such reactive centers, and subsequent de-protection at the end of the synthetic transformations, can be accomplished following standard procedures described, for instance, in Peter G.M. Wuts - Green's Protective Groups in Organic Synthesis, Fifth Edition, John Wiley & Sons Inc., 2014.

It will be appreciated that where typical or preferred experimental conditions (i.e. reaction temperatures, time, moles of reagents, solvents , etc . ) are given, other experimental conditions can also be used unless otherwise stated. Optimum reaction conditions may vary with the particular reactants or solvents used, but such conditions can be determined by the person skilled in the art, using routine optimization procedures.

The synthesis of a compound of Formula (I), according to the synthetic processes described below, can be conducted in a stepwise manner, whereby each intermediate is isolated and purified by standard purification techniques such as, for example, column chromatography, before carrying out the subsequent reaction. Alternatively, two or more steps of the synthetic sequence can be carried out in a so-called "one- pot" procedure, as known in the art, whereby only the compound resulting from the two or more steps is isolated and purified.

The compounds of Formula (I), prepared with the methods described herein below, may be treated or purified by conventional techniques or means for example by filtration, distillation, chromatography, recrystallization and combination thereof.

The salts of compounds of Formula (I) may be prepared by reacting a basic compound with the desired acid in solution, or by reacting an acidic compound with the desired base in solution . A second aspect of the present invention relates to a pharmaceutical composition comprising a compound of Formula (I) wherein:

Ai and A2 are selected from the group consisting of CH2 and NRi provided that Ai and A2 are not both at the same time CH₂ or NRi,

Ri is selected from the group consisting of H, CH₃ and (CH_{2) 2-4}-R₂,

R₂ is selected from the group consisting of H, COOR3 and CH2OH,

R₃ is selected from the group consisting of H and C1-4 alkyl ,

R₄, R5, R6, R7, Re, R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C1-4 alkyl, halogen and OH.

n is selected from 1 and 2 and at least a pharmaceutically acceptable excipient.

A person skilled in the art is aware of a whole variety of such excipient compounds suitable to formulate a pharmaceutical composition.

The compounds of the invention, together with a conventionally employed excipient may be placed into the form of pharmaceutical compositions and unit dosages thereof, and in such form may be employed as solids, such as tablets or filled capsules, or liquids such as solutions, suspensions, emulsions, elixirs, or capsules filled with the same, all for oral use, or in the form of sterile injectable solutions for parenteral administration (including subcutaneous and intravenous use) .

Such pharmaceutical compositions and unit dosage forms thereof may comprise ingredients in conventional proportions, with or without additional active compounds or principles, and such unit dosage forms may contain any suitable effective amount of the active ingredient commensurate with the intended daily dosage range to be employed .

Pharmaceutical compositions containing a compound of this invention can be prepared in a manner well known in the pharmaceutical art and comprise at least one active compound. Generally, the compounds of this invention are administered in a pharmaceutically effective amount. The amount of the compound actually administered will typically be determined by a physician, in the light of the relevant circumstances, including the condition to be treated, the chosen route of administration, the actual compound administered, the age, weight, and response of the individual patient, the severity of the patient's symptoms, and the like.

The pharmaceutical compositions of the present invention can be administered by a variety of routes including oral, rectal, subcutaneous, intravenous, intramuscular, intranasal and pulmonary routes. The compositions for oral administration can take the form of bulk liquid solutions or suspensions, or bulk powders. More commonly, however, the compositions are presented in unit dosage forms to facilitate accurate dosing. The term "unit dosage forms" refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical excipient. Typical unit dosage forms include pre-filled, pre-measured ampoules or syringes of the liquid compositions or pills, tablets, capsules or the like in the case of solid compositions.

Liquid forms suitable for oral administration may include a suitable aqueous or non-aqueous vehicle with buffers, suspending and dispensing agents, colorants, flavours and the like. Solid forms may include, for example, any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatine; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel or corn starch; a lubricant such as magnesium stearate; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavouring agent such as peppermint, methyl salicylate, or orange flavouring.

Injectable compositions are typically based upon injectable sterile saline or phosphate-buffered saline or other injectable carriers known in the art.

The pharmaceutical compositions may be in the form of tablets, pills, capsules, solutions, suspensions, emulsion, powders, suppository and as sustained release formulations.

If desired, tablets may be coated by standard aqueous or non-aqueous techniques. In certain embodiments, such compositions and preparations can contain at least 0.1 percent of active compound. The percentage of active compound in these compositions may, of course, be varied and may conveniently be between about 1 percent to about 60 percent of the weight of the unit. The amount of active compound in such therapeutically useful compositions is such that therapeutically active dosage will be obtained. The active compounds can also be administered intranasal as, for example, liquid drops or spray.

The tablets, pills, capsules, and the like may also contain a binder such as gum tragacanth, acacia, corn starch or gelatin; excipients such as calcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, lactose or saccharin. When a dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier such as a fatty oil. Various other materials may be present as coatings or to modify the physical form of the dosage unit. For instance, tablets may be coated with shellac, sugar or both. A syrup or elixir may contain, in addition to the active ingredient, sucrose as a sweetening agent, methyl and propyl parabens as preservatives, a dye and a flavoring agent such as cherry or orange flavor. To prevent breakdown during transit through the upper portion of the gastrointestinal tract, the composition be an enteric coated formulation.

Compositions for pulmonary administration include, but are not limited to, dry powder compositions consisting of the powder of a compound of Formula (I) or a salt thereof, and the powder of a suitable carrier and/or lubricant. The compositions for pulmonary administration can be inhaled from any suitable dry powder inhaler device known to a person skilled in the art.

Administration of the compositions is performed under a protocol and at a dosage sufficient to reduce the inflammation and pain in the subject. In some embodiments, in the pharmaceutical compositions of the present invention the active principle or active principles are generally formulated in dosage units. The dosage unit may contain from 0.1 to 1000 mg of a compound of Formula (I) per dosage unit for daily administration.

In some embodiments, the amounts effective for a specific formulation will depend on the severity of the disease, disorder or condition, previous therapy, the individual's health status and response to the drug. In some embodiments, the dose is in the range from 0.001% by weight to about 60% by weight of the formulation.

When used in combination with one or more other active ingredients, the compound of the present invention and the other active ingredient may be used in lower doses than when each is used singly.

Concerning formulations with respect to any variety of routes of administration, methods and formulations for the administration of drugs are disclosed in Remington' s Pharmaceutical Sciences, 17th Edition, Gennaro et al . Eds., Mack Publishing Co., 1985, and Remington's Pharmaceutical Sciences, Gennaro AR ed. 20th Edition, 2000, Williams & Wilkins PA, USA, and Remington: The Science and Practice of Pharmacy, 21st Edition, Lippincott Williams & Wilkins Eds., 2005; and in Loyd V. Allen and Howard C. Ansel, Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems, 10th Edition, Lippincott Williams & Wilkins Eds., 2014.

The above described components for orally administered or injectable compositions are merely representative.

The compounds of this invention can also be administered in sustained release forms or from sustained release drug delivery systems.

A third aspect of the present invention relates to compounds of Formula (I), including those compounds of formula (I) wherein Ri is H, or the pharmaceutical composition as disclosed above, for the use as a medicament.

Particularly preferred compounds for use as a medicament are:

OXA15 n=3 R=COOCH₃ OXA24 n=3 R=COOCH₃ OXA28 n=3 R=COOCH₃ OXA16 n=3 R=COOH OXA40 n=3 R=COOH OXA39 n=3 R=COOH OXA17 n=3 R=CH₂OH OXA42 n=3 R=CH₂OH OXA41 n=3 R=CH₂OH OXA33 n=2 R=COOCH₃ OXA44 n=2 R=COOCH₃ OXA43 n=2 R=COOCH₃ OXA45 n=2 R=CH₂OH OXA47 n=2 R=CH₂OH OXA46 n=2 R=CH₂OH OXA36 n=4 R=CH₃ OXA38 n=4 R=CH₃ OXA37 n=4 R=CH₃

In particular, compounds of Formula (I) as disclosed above, included those wherein Ri is H, or the pharmaceutical composition thereof can be used in the prevention and/or in treatment of a disorder selected from the group consisting of gastrointestinal disorders, liver diseases, cardiovascular and vascular diseases, pulmonary and metabolic diseases, infectious diseases, cancer, renal disorders, inflammatory disorders including immune-mediated disorders, and neurological disorders.

In one embodiment, the immune-mediated inflammatory disorders include autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome, scleroderma also known as systemic sclerosis, spondyloarthritis , vasculitis, sarcoidosis, Mediterranean fever, and other hereditary autoinflammatory diseases, polymyositis and dermatomyositis , Behcet's syndrome.

In one embodiment, the infectious diseases are selected from the group of Acquired Immuno-Deficiency Syndrome (AIDS) and related disorders, virus B and virus C infections.

In one embodiment, neurological disorders include Alzheimer's disease and other forms of dementia, Parkinson and other movement disorders, amyotrophic lateral sclerosis and other motor neuron disorders, multiple sclerosis and other demyelinating diseases, ischemic stroke, myasthenia and muscular dystrophy.

In one embodiment, the liver disorders include primary biliary cirrhosis (PBC) , cerebrotendinous xanthomatosis

(CTX) , primary sclerosing cholangitis (PSC) , drug induced cholestasis , intrahepatic cholestasis of pregnancy, parenteral nutrition associated cholestasis, bacterial overgrowth or sepsis associated cholestasis, autoimmune hepatitis, chronic viral hepatitis, alcoholic liver disease, nonalcoholic fatty liver disease (NAFLD) , nonalcoholic steatohepatitis (NASH) , liver transplant, congenital hepatic fibrosis, granulomatous liver disease, intra- or extrahepatic malignancy, Wilson's disease, hemochromatosis, and alpha 1-antitrypsin deficiency.

In one embodiment, the gastrointestinal disorders include inflammatory bowel disease (IBD) (including Crohn's disease, ulcerative colitis and undetermined colitis), irritable bowel syndrome (IBS), bacterial overgrowth, acute and chronic pancreatitis, malabsorption, post-radiation colitis, and microscopic colitis.

In one embodiment, the renal disorders include diabetic nephropathy, hypertensive nephropathy, chronic glomerulonephritis including chronic transplant glomerulonephritis, chronic tubule interstitial diseases and vascular disorders of the kidney.

In one embodiment, the cardiovascular diseases include atherosclerosis, arteriosclerosis, dyslipidemia, hypercholesterolemia, hypertriglyceridemia, hypertension also known as arterial hypertension, inflammatory heart diseases including myocarditis and endocarditis, ischemic heart disease, stable angina, unstable angina, myocardial infarction, cerebrovascular diseases including ischemic stroke .

In one embodiment, the vascular diseases include pulmonary heart disease such as pulmonary hypertension, peripheral artery disease (PAD) , also known as peripheral vascular disease (PVD) peripheral artery occlusive disease, and peripheral obliterative arteriopathy .

In one embodiment, pulmonary disorders include asthma, cystic fibrosis, obstructive respiratory diseases, interstitial lung disease including, but not limited to, primary or secondary pulmonary fibrosis.

In one embodiment, the metabolic disease is selected from the group of diseases comprising insulin resistance, metabolic syndrome, Type I and Type II diabetes, hypoglycaemia, disorders of the adrenal cortex including adrenal cortex insufficiency. Metabolic diseases also include obesity and conditions associated with bariatric surgery .

In one embodiment, cancer is selected from the group comprising liver cancer, bile duct cancers, oesophageal cancer, pancreatic cancer, gastric cancer, colon-rectal cancer, breast cancer, ovarian cancer and the condition associated with chemotherapy resistance. Further characteristics of the present invention will result from the following description of some merely illustrative and non-limiting examples.

The following abbreviations are used in the attached examples.

Methylene chloride (CH2CI2) , hydroxylamine hydrochloride (NH2OH) , methanol (MeOH) , potassium carbonate (K2CO3) , sodium sulphate (Na2SC>4) , N, N-Diisopropylethylamine (DIPEA), dimethylformamide (DMF) , (2- (lH-benzotriazol-1- yl) -1, 1, 3, 3-tetramethyluronium hexafluorophosphate (HBTU) , lithium bromide (LiBr) , sodium bicarbonate (NaHCCb) , trifluoroacetic acid (TFA) , tetrahydrofuran (THF) , lithium hydroxide (LiOH) , hydrochloric acid (HC1), ethyl acetate (EtOAc) , nitrogen (N2) , water (H2O) , hour (h) , room temperature (rt) , retention time (tid .

When not otherwise indicated, ¹H NMR was recorded on Varian Inova 400 MHz, using CDCI3 as solvent, and ¹³C NMR was recorded on Varian Inova 100 MHz, using CDCI3 as solvent.

BEST MODE FOR CARRYING OUT THE INVENTION

Examples

EXAMPLE 1. PREPARATION OF OXA7 , OXA20, OXA21

The key step of synthetic protocol was the preparation of the intermediate amidoxime 2 that in turn was coupled to the corresponding N-Boc protected aminoacid. Acid deprotection afforded OXA7, OXA20, OXA21 (Scheme 1) .

a) NH₂OH HC1, K₂C0₃, CH₃OH, reflux, quantitative yield; b) N- Boc-Inp-OH, DIEA, HBTU, DMF, 80 °C, 80%; c) TFA, CH₂C1₂, 2 h; d) N-Boc-L-Pip-OH, DIEA, HBTU, DMF, 80 °C, 78%; e) N-Boc- L-Pro-OH, DIEA, HBTU, DMF, 80 °C, 83%.

Step a . Preparation of amidoxime 2

To a solution of 2-naphthonitrile 1 (1 eq.) in dry MeOH,

K₂CO_{3 (}1.5 mol eq.) and hydroxylamine hydrochloride (2.5 mol eq.) were added, and the mixture was stirred at reflux for 2 h, under a nitrogen atmosphere. The resulting solution was then concentrated under vacuum, diluted with water and extracted with CH₂CI₂. The organic phases were dried (Na2SC>4) , filtered and concentrated in vacuo to give amidoxime 2 in quantitative yield, that were subjected to next step without any purification.

Example 1A. Preparation of 3- (naphthalen-2-yl) -5- (piperidin-4-yl) -1 ,2 , 4-oxadiazole (OXA7)

Steps b,c. DIPEA (1.8 mol eq.) was added to a solution of 2 (1 mol eq.) and N-Boc-isonipecotic acid (1.2 mol eq.) dissolved in DMF dry. HBTU (1.5 mol eq.), as coupling agent, was then added to the mixture at room temperature. The mixture was stirred vigorously at 80 °C for 12 h, then partitioned between water and EtOAc. The organic layer was collected and washed twice with a saturated LiBr solution, then with saturated NaHCCb solution and brine, dried over Na2SC>4, filtered and concentrated under reduced pressure. The resulted residue was purified on silica column using CH2CI2 100%, to give an intermediate that was subjected to a deprotection with CH2CI2: TFA 1:1 (1 mL) for 2 h. The resulted residue was purified on silica column using hexane and EtOAc 99:1 to give OXA7 in 80% yield.

An analytic sample was further purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (55:45) as eluent (flow rate 1 mL/min, t_R=8.6 min);

OXA7 : C₁₇H₁₇N₃O

¾ NMR (500 MHz, CD₃OD) : d_H 8.62 (1H, s), 8.11 (1H, d, J =

8.6 Hz), 8.00 (1H, d, J = 8.6 Hz), 7.99 (1H, ovl), 7.94 (1H, d, J = 7.2 Hz), 7.60 (1H, ovl), 7.59 (1H, ovl ) , 3.54 (3H, m) , 3.26 ( 2H, m) , 2.44 (2H, dd, J=14.5, 2.8 Hz), 2.19 (2H, m) ;

6c 181.7, 169.4, 136.1, 134.0, 129.9, 129.8, 128.9(2C), 128.8 ( 2C) , 128.1, 125.3, 124.6, 44.0 (2C), 32.9, 27.1 (2C).

Example IB. Preparation of (S) -3- (naphthalen-2-yl) -5- (piperidin-2-yl) -1 ,2 , 4-oxadiazole (OXA21)

Steps d,c. OXA21 was prepared from 2, in the same operative conditions described in steps b) and c) , example 1A using N- Boc-L-pipecolic acid in step d. HPLC purification on a Luna Synergi Polar-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (50:50) as eluent (flow rate 1 mL/min, t_R=14.0 min) afforded OXA21.

OXA21 C17H17N3O

d_H 8.67 (1H, s), 8.14 (1H, d, J = 8.5 Hz), 8.02 (1H, d, J =

8.7 Hz), 7.98 (1H, ovl), 7.95 (1H, d, J = 7.4 Hz), 7.62

(1H, ovl), 7.60 (1H, ovl), 4.90 (1H, ovl), 3.60 (1H, d, J=

12.3), 3.25 (1H, m) , 2.51 (1H, m) , 2.03 (3H, m) , 1.81 (2H, m) ;

6_c 175.9, 169.2, 135.9, 134.1, 129.8, 129.6, 129.2, 128.8

( 2C) , 127.9, 124.3, 124.2, 52.9, 45.7, 28.1, 22.5, 22.0. Example 1C. (S) -3- (naphthalen-2-yl) -5- (pyrrolidin-2-yl) -

1 ,2 , 4-oxadiazole (OXA20)

Steps e,c. OXA20 was prepared from 2, in the same operative conditions described in steps b) and c) , example 1A using N-Boc-L-proline in step e. HPLC purification on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (50:50) as eluent (flow rate 1 mL/min, t_R=11.0 min) afforded OXA20.

OXA20 C₁₆H₁₅N₃O

d_H 8.65 (1H, s), 8.12 (1H, d, J = 8.5 Hz), 8.02 (1H, d, J = 8.6 Hz), 7.99 (1H, ovl), 7.95 (1H, d, J = 7.1 Hz), 7.61 (1H, ovl), 7.60 (1H, ovl), 5.19 (1H, t, J= 7.6 Hz), 3.59 (1H, m) , 3.58 (1H, m) , 2.69 (2H, m) , 2.29 (2H, m) ;

¹³C NMR (125 MHz, CD₃OD) 6_C 176.3, 168.8, 136.3, 134.3, 130.1, 129.8, 129.2, 129.0 (2C), 128.1, 124.4, 124.3, 55.6, 47.3, 30.3, 24.6.

EXAMPLE 2. GENERAL PROCEDURE FOR N-ALKYLATION ON OXA7

a) Acyl bromide, DIPEA in CH₃CN, 60 °C; b) LiOH in THF/H₂O, 0 °C then room temperature ; c) DIBAL-H in THF, 0 °C; d) alkyl bromide, DIPEA in CH₃CN, 60 °C. Step a . OXA7 (1 mol eq.) , N, N-diisopropylethylamine (1.5 mol eq.) and the required bromide methyl ester Br (CH2) _nCOOMe (1.1 mol eq.) in dry acetonitrile were placed in a round bottom flask and stirred at room temperature under nitrogen. After completion of the reaction (monitored by TLC) , the resulting solution was concentrated under vacuum, diluted with water and extracted with CH2CI2. The organic fraction was dried over NaSCh and the solvent was removed under reduced pressure to yield the corresponding N-alkylated esters as crude products.

Step b . Each N-alkylated ester was dissolved in THF/H2O (3:1) and treated with LiOH hydrate (2 mol eq.) at 0 °C. The resulting mixture was stirred at rt for 24 h, followed by treatment with 0.5 N HC1, until pH reached 7-8, then was partitioned three times with EtOAc. The combined organic extracts were dried over Na2S0₄, filtered and concentrated in vacuum to afford the corresponding N-alkylated carboxylic acids .

Step c . Each N-alkylated ester was dissolved in THF and cooled to -78 °C under N2 atmosphere while a solution of diisobutylammonium hydride (1.7 M in toluene, 2 mol eq.) was added dropwise. The reaction was allowed to warm slowly to rt and stirred for 48 h. The reaction was quenched by slow addition of MeOH and then a solution of saturated sodium potassium tartrate was added and stirred for 1 h. The mixture was partitioned three times, and the combined organic extracts dried over Na2SC>4.

Step d. OXA7 (1 mol eq.) , N, N-diisopropylethylamine (3 mol eq.)_/ 1-bromopentane (1.5 mol eq.) in acetonitrile dry, were placed in a round bottom flask and stirred at 60 °C over night. After completion of reaction (monitored by TLC) , the resulting solution was then concentrated under vacuum, diluted with water and extracted with CH2CI2. The organic fraction was dried over NaSCh and the solvent was removed under reduced pressure to yield the crude product.

Example 2A. Methyl 4- (4- (3- (naphthalen-2-yl) -1 ,2 ,4- oxadiazol-5-yl) piperidin-l-yl) butanoate (OXA15)

OXA15 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (75:25) as eluent (flow rate 1 mL/min, t_R=21.0 min) .

OXA15 C22H25N3O3

¾ NMR (500 MHz, CD3OD) : d_H 8.61 (1H, s), 8.10 (1H, d, J = 8.5 Hz), 7.99 (1H, ovl), 7.98 (1H, ovl), 7.93 (1H, d, J = 7.6 Hz), 7.59 (1H, ovl), 7.58 (1H, ovl), 3.68 (3H, s), 3.14

(1H, m) , 3.03 ( 2H, d, J= 11.3 Hz), 2.44 (2H, t, J=7.4 Hz),

2.39 ( 2H, t, J= 7.2 Hz), 2.25 (2H, m) , 2.22 (2H, m) , 2.03

(2H, m), 1.86 (2H, m);

6c 184.5, 175.8, 168.7, 136.1, 134.0, 129.9, 129.8, 128.9, 128.8 (2C), 128.1, 125.1, 124.6, 58.9, 53.7 (2C), 52.1, 35.4,

32.6, 30.1 ( 2C ) , 22.7.

Example 2B. 4- (4- (3- (naphthalen-2-yl) -1 ,2 ,4-oxadiazol-5- yl) piperidin-l-yl) butanoic acid (OXA16)

OXA16 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (7:3) as eluent (flow rate 1 mL/min, t_R=21.0 min) .

OXA16 C21H23N3O3

¾ NMR (500 MHz, CD₃OD) : d_H 8.61 (1H, s), 8.10 (1H, d, J = 8.6 Hz), 7.99 (2H, d, J= 8.6 Hz), 7.93 (1H, d, J = 7.5 Hz),

7.59 (1H, ovl), 7.58 (1H, ovl), 3.45 (3H, m) , 2.98 (4H, m) ,

2.43 ( 4H, m) , 2.25 (2H, m) , 1.93 (2H, m) ;

6c 182.4, 169.7, 155.5, 132.6, 130.2 (2C), 128.3 (2C), 127.3, 82.1, 69.9, 55.7, 54.0, 41.8, 28.3 (3C) .

Example 2C. 4- (4- (3- (naphthalen-2-yl) -1 ,2 ,4-oxadiazol-5- yl) piperidin-l-yl) butan-l-ol (OXA17)

OXA17 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (75:25) as eluent (flow rate 1 mL/min, t_R=24.0 min) .

OXA17 C21H25N3O2

¾ NMR (500 MHz, CD₃OD) : d_H 8.61 (1H, s), 8.09 (1H, d, J =

8.4 Hz), 7.99 ( 2H, d, J= 8.3 Hz), 7.93 (1H, d, J = 8.0 Hz), 7.58 (1H, ovl), 7.57 (1H, ovl), 3.59 (2H, t, J= 5.9 Hz), 3.18 (1H, m) , 3.07 (2H, d, J= 11.4 Hz), 2.47 (2H, t, J=7.2 Hz), 2.30 ( 2H, m) , 2.22 (2H, m) , 2.02 (2H, m) , 1.66 (2H, m)

1.60 ( 2H, m) ;

6c 184.5, 168.6, 136.1, 134.0, 129.9, 129.8, 128.9, 128.8

( 2C ) , 128.1, 125.0, 124.6, 62.8, 59.7, 53.7 (2C), 35.4, 32.0, 30.2 ( 2C ) , 24.5.

Example 2D. Methyl 3- (4- (3- (naphthalen-2-yl) -1 ,2 ,4- oxadiazol-5-yl) piperidin-l-yl) propanoate (OXA33)

OXA33 was purified by HPLC on a Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (80:20) as eluent (flow rate 1 mL/min, t_R=13.5 min) .

OXA33 C21H23N3O3

¾ NMR (500 MHz, CD3OD) : d_H 8.61 (1H, s), 8.10 (1H, d, J =

8.5 Hz), 7.99 (1H, ovl), 7.98 (1H, ovl), 7.93 (1H, d, J =

7.6 Hz), 7.59 (1H, ovl), 7.57 (1H, ovl), 3.70 (3H, s), 3.16 (1H, m) , 3.02 (2H, d, J= 11.3 Hz), 2.76 (2H, t, J=7.4 Hz),

2.59 ( 2H, t, J= 7.2 Hz), 2.31 (2H, m) , 2.20 (2H, m) , 2.02

(2H, m) ;

6c 183.6, 174.4, 169.5, 136.1, 134.5, 129.9, 129.8, 128.9,

128.8 ( 2C ) , 128.0, 125.5, 124.6, 54.7, 53.5 (2C), 52.2, 35.4, 32.6, 30.3 (2C) .

Example 2E . 3- (4- (3- (naphthalen-2-yl) -1 ,2 ,4-oxadiazol-5- yl) piperidin-l-yl) propan-l-ol (OXA45)

OXA45 was purified by HPLC on a Luna Omega Polar Cl 8 (5 pm;

4.6 mm i.d. x 250 mm) with Me0H/H₂0 (75:25) as eluent (flow rate 1 mL/min, t_R=13.3 min) .

OXA45 C20H23N3O2

¾ NMR (500 MHz, CD₃OD) : d_H 8.61 (1H, s), 8.10 (1H, d, J =

8.5 Hz), 7.99 (1H, ovl), 7.98 (1H, ovl), 7.93 (1H, d, J = 7.6 Hz), 7.58 (2H, ovl), 3.64 (2H, t, J=6.3) 3.17 (1H, m) , 3.07 ( 2H, d, J= 11.2 Hz), 2.56 (2H, t, J=7.6 Hz), 2.29 (2H, t, J=11.2 ) , 2.20 ( 2H, d, J=12.4), 2.03 (2H, m) , 1.79 (2H, m) ;

6_c 183.6, 169.4, 136.1, 134.5, 129.9 (2 C), 128.9, 128.7 (2C), 127.9, 125.5, 124.6, 61.8, 57.1, 53.7 (2C), 35.4, 30.2 (2C),

30.1.

Example 2F. 3- (naphthalen-2-yl) -5- (l-pentylpiperidin-4-yl) - 1 ,2 ,4-oxadiazole (OXA36)

OXA36 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (88:12) as eluent (flow rate 1 mL/min, t_R=11.7 min) .

OXA36 C₂₂H₂₇N₃O

d_H 8.62 (1H, s) , 8.11 (1H, d, J = 8.6 Hz), 8.00 (1H, ovl), 7.99 (1H, ovl), 7.93 (1H, d, J = 7.2 Hz), 7.59 (1H, ovl), 7.58 (1H, ovl), 3.14 (1H, m) , 3.03 (2H, m),2.40 (2H, m) , 2.21 ( 4H, m) , 2.03 (2H, m) , 1.57 (2H, m) , 1.37 (2H, m) , 1.33 ( 2H, m) , 0.93 (3H, t, J= 7.1 Hz);

d_a 184.5, 168.7, 136.1, 134.0, 129.9, 129.8, 128.9 (2C),

128.8, 128.1, 124.6, 124.3, 53.7 (2C), 35.4, 30.1 (2C), 14.3. EXAMPLE 3. GENERAL PROCEDURE FOR N-ALKYLATION ON OXA21

Alkylation on OXA21 with the desired bromide methyl ester Br (CH2) nCOOMe or the desired alkyl bromide Br(CH2)_nCH3 was performed in the same operative condition described in example 2 steps a) and d) , respectively. Hydrolysis and reduction at the methyl ester functional group were performed in the same operative condition described in example 2 steps b) and c) .

a) Acyl bromide, DIPEA in CH₃CN, 60 °C; b) LiOH in THF/H2O, 0 °C then room temperature ; c) DIBAL-H in THF, 0 °C; d) alkyl bromide, DIPEA in CH₃CN, 60 °C.

Example 3A. (S) -methyl 4- (2- (3- (naphthalen-2-yl) -1 ,2 ,4- oxadiazol-5-yl) piperidin-l-yl) butanoate (OXA28)

OXA28 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (75:25) as eluent (flow rate 1 mL/min, t_R=31.2 min) .

OXA28 C22H25N3O3

d_H 8.62 (1H, s) , 8.11 (1H, d, J = 8.6 Hz), 8.00 (1H, ovl),

7.99 (1H, ovl), 7.93 (1H, d, J = 7.2 Hz), 7.59 (1H, ovl), 7.58 (1H, ovl), 4.04 (1H, m) , 3.56 (3H, s),3.09 (2H, m) ,

2.40 ( 2H, m) , 2.34 (2H, t, J= 7.1 Hz), 1.98 (2H, m) , 1.81

(2H, m), 1.74 (2H, m), 1.55 (2H, m);

6_c 181.3, 175.5, 169.2, 136.2, 134.4, 129.9, 129.8, 128.9

( 2C) , 128.7, 128.0, 125.3, 124.6, 59.7, 56.1, 52.0, 51.7, 32.2, 31.6, 26.2, 22.9, 22.7.

Example 3B. (S) -A- (2- (3- (naphthalen-2-yl) -1 ,2 , 4-oxadiazol-

5-yl) piperidin-l-yl) butanoic acid (OXA39)

OXA39 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (7:3) as eluent (flow rate 1 mL/min, t_R=14.8 min) .

OXA39 C21H23N3O3

d_H 8.65 (1H, s), 8.12 (1H, d, J = 8.6 Hz), 8.01 (1H, ovl),

8.00 (1H, ovl), 7.94 (1H, d, J = 7.6 Hz), 7.61 (1H, ovl),

7.59 (1H, ovl), 4.16 (1H, dd, J= 6.8, 4.5 Hz), 3.19 (1H, m) , 2.55 ( 2H, m) , 2.51 (1H, m) , 2.32 (2H, m) , 2.03 (2H, m) , 1.82 (2H, m), 1.77 (2H, m), 1.58 (2H, m);

d_a 181.2, 178.2, 169.4, 136.4, 134.6, 129.9 (2C), 129.0,

128.9, 128.8, 128.0, 125.0, 124.7, 59.7, 56.8, 51.7, 33.7,

31.4, 26.1, 23.0, 22.9. Example 3C. (S) -4- (2- (3- (naphthalen-2-yl) -1 ,2 , 4-oxadiazol-

5-yl) piperidin-l-yl) butan-l-ol (OXA41)

0XA41 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (75:25) as eluent (flow rate 1 mL/min, t_R=18.7 min) .

OXA41 C21H25N3O2

d_H 8.63 (1H, s), 8.12 (1H, d, J = 8.6 Hz), 8.01 (1H, d, J =

8.7 Hz), 7.99 (1H, ovl), 7.94 (1H, d, J = 7.4 Hz), 7.60 (1H, ovl), 7.59 (1H, ovl), 4.08 (1H, br t, J =5.9 Hz), 3.52 (2H, t, J= 6.0 Hz), 3.14 (1H, m) , 2.46 (2H, m) , 2.43 (1H, m) , 2.01 ( 2H, m) , 1.89 (1H, m) , 1.76 (2H, m) , 1.61 (2H, m) , 1.54 (1H, m), 1.50 (2H, m);

6_c 181.7, 169.4, 136.2, 134.2, 129.9, 129.8, 129.0, 128.8

( 2C) , 128.1, 125.1, 124.6, 62.7, 59.6, 57.0, 51.6, 31.4, 31.3, 26.1, 23.8, 22.9.

Example 3D. (S) -methyl3- (2- (3- (naphthalen-2-yl) -1 ,2 ,4- oxadiazol-5-yl) piperidin-l-yl) propanoate (OXA43)

OXA43 was purified by HPLC on a Synergi Hydro-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (80:20) as eluent (flow rate 1 mL/min, t_R=17.5 min) .

OXA43 C21H23N3O3

d_H 8.63 (1H, s), 8.12 (1H, d, J = 8.6 Hz), 8.01 (1H, d, J =

8.7 Hz), 7.99 (1H, ovl), 7.94 (1H, d, J= 7.4 Hz), 7.60 (1H, ovl), 7.59 (1H, ovl), 4.13 (1H, br t, J= 5.6 Hz), 3.63 (3H s), 3.08 (1H, m) , 2.82 (1H, m) , 2.74 (1H, m) , 2.53 (2H, ovl), 2.52 (1H, ovl), 2.00 (2H, m) , 1.82 (1H, m) , 1.74 (2H, m) ,

1.55 ( 1H, m) ;

6_c 181.7, 174.4, 169.3, 136.2, 134.5, 129.9, 129.8, 128.9, 128.8 ( 2C) , 128.0, 125.3, 124.6, 59.2, 52.5, 52.2, 51.3, 33.0, 31.4, 26.4, 22.9.

Example 3E . (S) -3- (2- (3- (naphthalen-2-yl) -1 ,2 ,4-oxadiazol-

5-yl) piperidin-l-yl) propan-l-ol (OXA46)

OXA46 was purified by HPLC on a Luna Omega Polar Cl 8 (5 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (78:22) as eluent (flow rate 1 mL/min, t_R=11.0 min) .

OXA46 C20H23N3O2

d_H 8.63 (1H, s) , 8.12 (1H, d, J = 8.6 Hz), 8.01 (1H, ovl),

8.00 (1H, ovl), 7.94 (1H, d, J = 7.4 Hz), 7.60 (1H, ovl), 7.59 (1H, ovl), 4.06 (1H, dd, J=7.2, 4.3 Hz), 3.59 (2H, t,

J= 6.1 Hz), 3.13 (1H, m) , 2.57 (2H, m) , 2.46 (1H, m) , 1.99 (1H, m) , 1.87 ( 2H, m) , 1.73 (2H, m) , 1.72 (2H, m) , 1.56 (1H, m) ;

6_c 181.7, 169.4, 136.2, 134.5, 129.9, 129.8, 128.9 (2C), 128.8, 128.0, 125.1, 124.6, 61.6, 59.9, 54.6, 51.7, 31.8,

30.1, 26.3, 23.1.

Example 3F. (S) -3- (naphthalen-2-yl) -5- (l-pentylpiperidin-2- yl) -1 ,2 ,4-oxadiazole (OXA37)

OXA37 was purified by HPLC on a Luna Synergi Fusion-RP (4 mpi; 4.6 mm i.d. x 250 mm) with MeOH/PhO (85:15) as eluent (flow rate 1 mL/min, t_R=31.1 min) .

OXA37 C22H27N3O

d_H 8.67 (1H, s), 8.14 (1H, d, J = 8.5 Hz), 8.02 (1H, d, J = 8.7 Hz), 7.98 (1H, ovl), 7.95 (1H, d, J= 7.4 Hz), 7.62 (1H, ovl), 7.60 (1H, ovl), 4.04 (1H, br t, J= 6.2 Hz), 3.12 (1H, m) , 2.43 (2H, m) , 2.34 (1H, m) , 2.00 (2H, m) , 1.88 (1H, m) ,

1.75 ( 2H, m) , 1.55 (3H, m) , 1.27 (4H, m) , 0.87 (3H, t, J=

6.9 Hz) ;

6c 182.3, 169.5, 136.1, 134.5, 129.9, 129.8, 128.9 (2C), 128.7 ( 2C ) , 128.0, 124.6, 61.4, 55.9, 54.6, 31.3, 30.6, 29.2, 24.2, 22.3, 14.3.

EXAMPLE 4. GENERAL PROCEDURE FOR N-ALKYLATION ON OXA20

Alkylation on OXA20 with the desired bromide methyl ester Br (CH2) _nCOOMe or the desired alkyl bromide was performed in the same operative condition described in example 2 steps a) and d) , respectively. Hydrolysis and reduction at the methyl ester functional group were performed in the same operative condition described in example 2 steps b) and c) .

a) Acyl bromide, DIPEA in CH₃CN, 60 °C; b) LiOH in THF/H₂0,

0 °C then room temperature ; c) DIBAL-H in THF, 0 °C; d) alkyl bromide, DIPEA in CH₃CN, 60 °C.

Example 4A. (S) -methyl 4- (2- (3- (naphthalen-2-yl) -1 ,2 ,4- oxadiazol-5-yl) pyrrolidin-l-yl) butanoate (OXA24)

OXA24 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (75:15) as eluent (flow rate 1 mL/min, t_R=19.9 min) .

OXA24 C_2IH₂₃N₃0₃

d_H 8.63 (1H, s) , 8.12 (1H, d, J = 8.5 Hz), 8.00 (1H, ovl), 7.99 (1H, ovl), 7.94 (1H, d, J = 6.9 Hz), 7.59 (1H, ovl), 7.58 (1H, ovl), 4.06 (1H, dd, J= 8.5, 5.8 Hz), 3.56 (3H, s),

3.26 (1H, m) , 2.77 (2H, m) , 2.57 (2H, m) , 2.39 (2H, m) , 2.20 (1H, m) , 2.09 (1H, m) , 2.00 (1H, m) , 1.79 (2H, m) ;

6_c 182.3, 175.5, 169.5,136.2, 134.6, 130.0, 129.9, 129.0 ( 2C) , 128.8, 128.1, 125.3, 124.7, 61.6, 55.0, 54.7, 52.1

32.3, 31.4, 24.7, 24.4.

Example 4B. (S) -A- (2- (3- (naphthalen-2-yl) -1 ,2 , 4-oxadiazol-

5-yl) pyrrolidin-l-yl) butanoic acid (OXA40)

OXA40 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (7:3) as eluent (flow rate 1 mL/min, t_R=12 min) ;

OXA40 C20H21N3O3

d_H 8.63 (1H, s), 8.11 (1H, d, J = 8.5 Hz), 8.01 (1H, ovl), 7.99 (1H, ovl), 7.93 (1H, d, J = 7.6 Hz), 7.59 (1H, ovl),

7.58 (1H, ovl), 4.12 (1H, dd, J= 8.4, 6.0 Hz), 3.28 (1H, ovl), 2.79 (1H, m) , 2.61 (1H, ovl), 2.58 (1H, ovl), 2.37

(1H, ovl), 2.33 ( 2H, ovl), 2.19 (1H, m) , 2.10 (1H, m) , 2.02

(1H, m) , 181 ( 2H, m) ;

6_c 182.3, 178.0, 169.5, 136.1, 134.5, 129.9, 129.8, 129.0,

128.9, 128.8, 128.0, 125.3, 124.6, 61.5, 55.2, 54.4, 33.2,

31.4, 24.9, 24.3.

Example 4C. (S) -A- (2- (3- (naphthalen-2-yl) -1 ,2 , 4-oxadiazol-

5-yl) pyrrolidin-l-yl) butan-l-ol (OXA42)

OXA42 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (75:25) as eluent (flow rate 1 mL/min, t_R=14.2 min) .

OXA42 C20H23N3O2

d_H 8.63 (1H, s), 8.11 (1H, d, J = 8.5 Hz), 8.01 (1H, dovl), 7.99 (1H, ovl ) , 7.95 (1H, d, J = 7.1 Hz), 7.61 (1H, ovl), 7.60 (1H, ovl), 4.08 (1H, dd, J= 8.3, 6.1 Hz), 3.53 (2H, t, J= 5.9 Hz), 3.27 (1H, ovl), 2. IQ (1H, m) , 2.59 (1H, m) , 2.54 (1H, m) , 2.38 (1H, m) , 2.21 (1H, m) , 2.12 (1H, m) , 2.02 (1H, m) , 160 (2H, ovl), 1.57 (2H, ovl);

6c 182.3, 169.5, 136.1, 134.4, 130.0, 129.8, 129.1, 128.9,

128.7, 128.0, 125.4, 124.6, 62.7, 61.4, 55.8, 54.5, 31.5,

31.3, 26.1, 24.2.

Example 4D. (S) -methyl 3- (2- (3- (naphthalen-2-yl) -1,2,4- oxadiazol-5-yl) pyrrolidin-l-yl) propanoate (OXA44)

OXA44 was purified by HPLC on a Luna Synergi Fusion-RP (4mpi; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (80:20) as eluent (flow rate 1 mL/min, t_R=7.0 min) .

OXA44 C20H21N3O3

d_H 8.62 (1H, s), 8.10 (1H, d, J = 8.5 Hz), 8.00 (1H, dovl),

7.99 (1H, ovl), 7.96 (1H, d, J = 7.1 Hz), 7.61 (1H, ovl),

7.60 (1H, ovl), 4.12 (1H, dd, J= 8.3, 5.4 Hz), 3.61 (3H, s), 3.24 (1H, m) , 3.08 (1H, m) , 2.83 (1H, m) , 2.62 (1H, m) , 2.54 (2H,m), 2.38 (1H, m) , 2.21 (1H, m) , 2.08 (1H, m) , 2.01 (1H, m) ;

6c 182.4, 174.3, 169.5, 136.2, 134.5, 129.9, 129.8, 128.9,

128.8, 128.7, 128.0, 125.3, 124.6, 61.2, 54.5, 52.2, 50.9,

34.4, 31.5, 24.5.

Example 4E . (S) -3- (2- (3- (naphthalen-2-yl) -1 ,2 ,4-oxadiazol- 5-yl) pyrrolidin-l-yl) propan-l-ol (OXA47)

OXA47 was purified by HPLC on a Luna Omega Polar Cl 8 (5 pm; 4.6 mm i.d. x 250 mm) with MeOH/fhO (68:32) as eluent (flow rate 1 mL/min, t_R=27.0 min) .

OXA47 C19H21N3O2

d_H 8.63 (1H, s) , 8.11 (1H, d, J = 8.5 Hz) , 8.01 (1H, d, ovl) , 7.99 (1H, ovl), 7.95 (1H, d, J = 7.1 Hz), 7.61 (1H, ovl), 7.60 (1H, ovl), 4.08 (1H, dd, J= 8.5, 5.8 Hz), 3.63 (2H, t, J= 6.1 Hz), 3.28 (1H, ovl), 2.88 (1H, m) , 2.62 (1H, m) , 2.59 (1H, m) , 2.40 (1H, m) , 2.20 (1H, m) , 2.11 (1H, m) , 2.02 (1H, m) , 1.76 ( 2H, ovl ) ;

6_c 182.3, 169.5, 136.4, 134.5, 129.9, 129.8, 129.0, 128.9,

128.8, 128.0, 125.4, 124.6, 61.6, 61.5, 59.2, 54.3, 32.2,

31.4, 24.3.

Example 4F. (S) -3- (naphthalen-2-yl) -5- (1-pentylpyrrolidin-

2-yl) -1 ,2 ,4-oxadiazole (OXA38)

OXA38 was purified by HPLC on a Luna Synergi Fusion-RP (4 pm; 4.6 mm i.d. x 250 mm) with Me0H/H₂0 (88:12) as eluent (flow rate 1 mL/min, t_R=13.6 min) .

OXA38 C21H25N3O

d_H 8.62 (1H, s) , 8.11 (1H, d, J = 8.6 Hz), 8.00 (1H, ovl),

7.99 (1H, ovl), 7.93 (1H, d, J = 7.2 Hz), 7.59 (1H, ovl),

7.58 (1H, ovl), 4.04 (1H, dd, J= 8.4, 6.1 Hz), 3.24 (1H, m) , 2.72 (1H, m) , 2.56 (1H, dd, J= 17.0, 8.5 Hz), 2.48 (1H, m) , 2.37 (1H, m) , 2.20 (1H, m) , 2.10 (1H, m) , 2.00 (1H, m) , 1.54

( 2H, m) , 1.28 (4H, m) , 0.86 (3H, t, J= 6.2 Hz);

6c 182.3, 169.5, 136.1, 134.5, 129.9, 129.8, 128.9 (2C), 128.7 ( 2C ) , 128.0, 124.6, 61.4, 55.9, 54.6, 31.3, 30.6, 29.2, 24.2, 22.3, 14.3.

EXAMPLE 5. BIOLOGICAL ACTIVITY

The biological activity of the selected compounds (Table 1) was tested in vitro using a cell model transfected with reporter genes, on the receptor FXR in comparison with the control agonist, chenodeoxycholic acid (CDCA) , a primary bile acid that functions as an endogenous ligand of the receptor. HepG2 cells were cultured at 37 °C in E-MEM medium (Earl's salt Minimum Essential Medium) with the addition of 10% fetal bovine serum (FBS), 1% L-glutamine, and 1% penicillin/streptomycin . The transfection experiments were performed using the reagent Fugene HD (Promega) according to the manufacturer's instructions. The cells were plated in 24-well plates at 5 ^c 10⁴ cells/well.

HepG2 cells were transfected with 100 ng of the vector pSG5-FXR, 100 ng of the vector pSG5-RXR, 100 ng of the vector pGL4.70 Renilla, a plasmid encoding the human Renilla gene, and 200 ng of the reporter vector p (hsp27 ) -TK-LUC containing the FXR responsive-element IR1 cloned from the promoter of heat shock protein 27 (hsp27) . At 24 h post-transfection, cells were stimulated for 18 h with test compounds alone and in presence of 10 mM CDCA.

After treatments, cells were lysed in 100 pL of lysis buffer (25 mM Tris-phosphate, pH 7.8; 2 mM DTT; 10% glycerol; 1% Triton X-100) ; 10 pL of the cellular lysate of each sample were assayed for luciferase activity using Dual Luciferase Reporter Assay System (Promega Italia S.r.l., Milan, Italy) according to the manufacturer's instructions. Luminescence was measured using Glomax 20/20 luminometer (Promega Italia S.r.l., Milan, Italy) . The luciferase activity (Luciferase

Recording Unit, RLU) was normalized using the activity of the Renilla (Renilla Recording Unit, RRU) . The IC₅₀ values of each compound were determined by constructing a dose- response curve on HepG2 cells transfected as described above and then treated with increasing concentrations of compounds (0.1-100 pM) in presence of 10 mM CDCA.

Table 1 reports the efficacy of the selected compounds included in Formula I as percent of antagonistic activities compared to that of CDCA for which the transactivation activity was considered equal to 100%. Each compound was tested at the concentration of 50 pM.

None of the compounds belonging to formula I showed agonistic activity on FXR.

None of the compounds belonging to formula I showed agonistic/antagonistic activity on GPBAR1.

For the GPBAR1 mediated transactivation, HEK-293T cells were transfected with 200 ng of the plasmid pGL4.29 (Promega) , a reporter vector containing the cAMP response element (CRE) cloned upstream of the luciferase reporter gene luc2P, 100 ng of the vector pCMVSport6-human GPBAR1, and 100 ng of the vector pGL4.70 Renilla, a plasmid encoding the human Renilla gene. In control experiments, HEK-293T cells were transfected only with vectors pGL4.29 (Promega) and pGL4.70 Renilla, to exclude any possibility that compounds could activate the CRE independently of the GPBAR1.

Table 1

Preferred examples included in the general formula lb are OXA7 and OXA17 with an efficacy of 80% and 95% in antagonizing CDCA transactivation and IC50 values of 0.58 mM and 1.17 mM, respectively.

Preferred examples included in the general formula Ic are OXA21, OXA28 and OXA41 with an efficacy of 96%, 85% and 82% in antagonizing CDCA transactivation and IC50 values of 0.127 mM, 0.067 and 7 mM.

Claims

1.- Compound of formula (I) :

wherein Ai and A2 are selected from the group consisting of CH2 and NRi provided that Ai and A2 are not at the same time CH2 or NRi,

Ri is selected from CH₃ and (CH_2)2-4-R₂,

R₂ is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R₃ is selected from the group consisting of H and C_1-4 alkyl ,

R₄, R₅, R6, R₇, Re, R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C_1-4 alkyl, halogen and OH.

n is selected from 1 and 2 or pharmaceutically acceptable salts and solvates.

2.- Compound according to claim 1, wherein n is 1.

3.- Compound according to claim 2, having the formula

(la)

wherein Ri is selected from CH3 and (CH2)2-4-R2,

R₂ is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R₃ is selected from the group consisting of H and C1-4 alkyl ,

R₄, R5, R6, R7, Re, R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C_1-4 alkyl, halogen and OH.

4.- Compound according to claim 1, wherein n is 2.

5.- Compound according to claim 4, having the formula lb

wherein Ri is selected from CH₃ and (CH_2)2-4-R₂,

R₂ is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R₃ is selected from the group consisting of H and C1-4 alkyl ,

R₄, R5, R6, R7, Re, R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C_1-4 alkyl, halogen and OH.

6.- Compound according to claim 4, having the formula

wherein Ri is selected from CH₃ and (CH_2)2-4-R₂,

R₂ is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R₃ is selected from the group consisting of H and Ci-₄ alkyl ,

R₄ , R5, R6, R7, Re, R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C_1-4 alkyl, halogen and OH.

7.- Compound according to any of claims 1 to 6, wherein the compound is selected from the group consisting of

OXA15 n=3 R=COOCH₃ OXA24 n=3 R=COOCH₃ OXA28 n=3 R=COOCH₃ OXA16 n=3 R=COOH OXA40 n=3 R=COOH OXA39 n=3 R=COOH OXA17 n=3 R=CH₂OH OXA42 n=3 R=CH₂OH OXA41 n=3 R=CH₂OH OXA33 n=2 R=COOCH₃ OXA44 n=2 R=COOCH₃ OXA43 n=2 R=COOCH₃ OXA45 n=2 R=CH₂OH OXA47 n=2 R=CH₂OH OXA46 n=2 R=CH₂OH OXA36 n=4 R=CH₃ OXA38 n=4 R=CH₃ OXA37 n=4 R=CH₃

8.- Pharmaceutical composition comprising a compound of Formula ( I ) :

wherein Ai and A2 are selected from the group consisting of CH2 and NRi provided that Ai and A2 are not at the same time CH2 or NRi,

Ri is selected from H, CH3 and (CH2)2-4-R2,

R2 is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R3 is selected from the group consisting of H and C_1-4 alkyl ,

R₄ , R5, R6 , R7, Re , R9 and Rio are independently selected from the group consisting of H, C_1-4 alkyl, O-C_1-4 alkyl, halogen and OH.

n is selected from 1 and 2 and at least a pharmaceutically acceptable excipient.

9.- Compound of Formula (I) :

wherein Ai and A2 are selected from the group consisting of CH2 and NRi provided that Ai and A2 are not at the same time CH2 or NRi,

Ri is selected from H, CH3 and (CH2)2-₄-R2,

R₂ is selected from the group consisting of H, CH₃, COOR₃ and CH₂OH,

R₃ is selected from the group consisting of H and Ci-₄ alkyl ,

R₄, R5, R6, R7, Re, R9 and Rio are independently selected from the group consisting of H, Ci-₄ alkyl, O-C1-4 alkyl, halogen and OH.

n is selected from 1 and 2 for the use as a medicament.

10.- The compounds according to claim 9 for use in the prevention and/or treatment of a disorder selected from the group consisting of gastrointestinal disorders, liver disorders, cardiovascular disorders, vascular disorders, pulmonary disorders, metabolic pathologies, infectious diseases, cancer, renal disorders, inflammatory disorders including immune- mediated, and neurological disorders.

11.- The compounds according to claim 10 for use according to claim 10, characterised in that said disorder is selected from the group consisting of systemic lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome, scleroderma, spondyloarthritis, vasculitis, sarcoidosis, Mediterranean fever, polymyositis and dermatomyositis, Behcet's syndrome, acquired immune deficiency and associated disorders, virus B and virus C infections, Alzheimer's disease and other dementias, Parkinson's disease and other movement disorders, amyotrophic lateral sclerosis and other motor neuron disorders, multiple sclerosis and other demyelinating diseases, myasthenia and muscular dystrophies, primary biliary cirrhosis, cerebrotendinous xanthomatosis, primary sclerosing cholangitis, drug-induced cholestasis, intrahepatic cholestasis of pregnancy, cholestasis associated with parenteral nutrition, cholestasis associated with bacterial proliferation or sepsis, autoimmune hepatitis, chronic viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, liver transplantation, congenital hepatic fibrosis, hepatic granulomatous disease, intra- or extra-hepatic malignant tumor, Wilson's disease, hemochromatosis, alpha 1- antitrypsin deficiency, inflammatory bowel disease, Crohn's disease, ulcerative rectocolitis, indeterminate colitis, irritable bowel syndrome, bacterial proliferation, acute and chronic pancreatitis, malabsorption, post-radiation colitis, microscopic colitis, diabetic nephropathy, hypertensive nephropathy, chronic glomerulonephritis, chronic graft glomerulonephritis, chronic tubulointerstitial diseases, kidney vascular disorders, atherosclerosis, arteriosclerosis, dyslipidaemia, hypercholesterolemia, hypertriglyceridemia, arterial hypertension, cardiac inflammatory disorders, myocarditis, endocarditis, cardiac ischemia, stable angina, unstable angina, myocardial infarction, cerebrovascular disorders, ischemic stroke, pulmonary hypertension, peripheral artery disease, peripheral artery occlusive disease, obliterative peripheral arteriopathy, asthma, cystic fibrosis, respiratory obstructive diseases, interstitial lung diseases, primary or secondary pulmonary fibrosis, insulin resistance, metabolic syndrome, type I and type II diabetes, hypoglycaemia, disorders of the adrenal cortex, failure of the adrenal cortex, obesity, conditions associated with bariatric surgery, liver cancer, cancers of the bile ducts, oesophageal cancer, pancreatic cancer, gastric cancer, colon-rectal cancer, breast cancer, ovarian cancer and the condition associated with resistance to chemotherapy.