Novel phosphoglicerate dehydrogenase inhibitors for the treatment of fibrosis

Abstract

The present invention generally relates to compounds of general formula (I) inhibiting 3-phosphoglycerate dehydrogenase (hereinafter PHGDH) receptor; the invention relates to compounds, including pharmaceutically acceptable salts thereof, and their use for the prevention and / or treatment of fibrosis, in particular idiopathic pulmonary fibrosis (IPF), as sole agent or in combinations with other active ingredients, as well as to the use of pharmaceutical compositions and combinations comprising said compounds.

Description

[0001] NOVEL PHOSPHOGLICERATE DEHYDROGENASE INHIBITORS FOR THE TREATMENT OF FIBROSIS

[0002] FIELD OF INVENTION

[0003] The present invention generally relates to compounds of general formula (I) inhibiting 3- phosphoglycerate dehydrogenase (hereinafter PHGDH) receptor; the invention relates to compounds, including pharmaceutically acceptable salts thereof, and their use for the prevention and / or treatment of fibrosis, in particular idiopathic pulmonary fibrosis (IPF), as sole agent or in combinations with other active ingredients, as well as to the use of pharmaceutical compositions and combinations comprising said compounds.

[0004] BACKGROUND OF THE INVENTION

[0005] 3 -phosphoglycerate dehydrogenase (PHGDH) is the enzyme that catalyzes the first ratelimiting step in the de novo biosynthesis of L-serine starting from glucose, which is the conversion of 3 -phosphoglycerate into 3-phosphohydroxypyruvate with a reduction of nicotinamide adenine dinucleotide (NAD+) to NADH, and it is considered as a major enzyme in the diversion of glycolysis towards serine synthesis. Serine, a critical amino acid for protein and nucleic acid biosynthesis, in turn is metabolized and incorporated into a variety of biomolecules including glycine (see Yang M., Vousden, K H., Nature Reviews Cancer 2016,16, 650-662).

[0006] PHGDH is required to promote collagen protein synthesis. Indeed, glycine accounts for one- third of all amino acids within the collagen molecule, and the high content of glycine is critical for the stabilization of collagen helix.

[0007] Collagen is the main structural protein in the extracellular space, and it is produced in excess in IPF patients during fibroblasts into myofibroblasts differentiation that accumulates within the fibrotic tissue and leads to loss of organ architecture and function.

[0008] Moreover, PHGDH and the serine / glycine synthesis pathway is part of a wider network which links glycolysis with one-carbon metabolism and nucleotide synthesis contributing to cell proliferation in pathologies such as inflammation and fibrosis.

[0009] Therefore, the PHGDH inhibition has the potential to reduce the aberrant production and release of collagen such as inhibit cell proliferation (see Selvarajah et al., Science Signaling, 2019; 12(582) :eaav 3048).

[0010] Various compounds have been described in the literature as potent PHGDH inhibitors.

[0011] Raze Therapeutics disclosed in various patent applications (for example WO2017156165) compounds which are effective as orthosteric PHGDH inhibitors, and their use in the treatment of many PHGDH-mediated disorders, in particular melanoma, breast, or lung cancer. Examples of PHGDH inhibitors useful for treating proliferative diseases, benign neoplasms, diseases associated with angiogenesis, inflammatory diseases, autoinflammatory diseases, and autoimmune diseases are disclosed in WO2016115463 (Whitehead Institute For Biomedical Research; Dana-Farber Cancer Institute, Inc).

[0012] Fibrosis is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodeling and the formation of permanent scar tissue (see Wynn, Thomas A., 2004 Nature Reviews 4 (8): 583-594).

[0013] Fibrosis can occur in many tissues within the body, typically as a result of inflammation or damage, and examples include liver, lungs, kidney, brain and heart.

[0014] Idiopathic pulmonary fibrosis (IPF) is a rare, progressive illness of the respiratory system, characterized by the thickening and stiffening of lung tissue, associated with the formation of scar tissue. It is a type of chronic scarring lung disease characterized by a progressive and irreversible decline in lung function, (see HR, Egan JJ, et al. American Journal of Respiratory and Critical Care Medicine, 2011, 183 (6): 788-824).

[0015] Despite the above prior art, there remains a potential for developing novel medicaments comprising a PHGDH inhibitor suitable for oral administration useful for the prevention and / or treatment of fibrosis, in particular IPF.

[0016] The underlying problem of the present invention therefore lies in the provision of a medicament comprising a compound of formula (I) as herein disclosed, for the prevention and / or treatment of fibrosis, in particular IPF, and at the same time a good oral profile, obtainable with a suitable BSEP (Bile Salt Export Pump inhibition) profile and good permeability.

[0017] In this respect, the state of the art does not describe or suggest derivatives of general formula (I) of the present invention having inhibitory activity on PHGDH which demonstrate good results in assays for the prevention and / or treatment of fibrosis, in particular IPF, and at the same time a suitable BSEP profile and a good permeability, which represent a solution to the aforementioned need..

[0018] SUMMARY OF THE INVENTION

[0019] In a first aspect the invention refers to a compound of formula (I) wherein

[0020] Ri is -(Ci-Ce)alkyl;

[0021] Rz is H or -(Ci-Ce)alkyl, optionally substituted with OR?, or Ri and Rz are fused together to form a -(C6-C7)heterocycloalkyl;

[0022] R3 is halogen;

[0023] R4 and R5 are independently H or selected from the group consisting of halogen, -OR7 and - (Ci-Ce)alkyl;

[0024] Re and R7 are independently H or -(Ci-Ce)alkyl; and pharmaceutically acceptable salts thereof.

[0025] In a second aspect, the invention refers to a pharmaceutical composition comprising a compound of formula (I) in a mixture with one or more pharmaceutically acceptable carrier or excipient.

[0026] In a third aspect, the invention refers to a compound of formula (I) for use as medicament.

[0027] In a further aspect, the invention refers to a compound of formula (I) for use in the prevention and / or treatment of fibrosis and / or diseases, disorders, or conditions that involve fibrosis.

[0028] In a further aspect, the invention refers to intermediate compounds that are useful in the preparation of compounds of formula (I).

[0029] DETAILED DESCRIPTION OF THE INVENTION

[0030] Unless otherwise provided, the term “compound of formula (I)” comprises in its meaning solvates, stereoisomers, tautomers, deuterated and pharmaceutically acceptable salts or solvates thereof.

[0031] The term “pharmaceutically acceptable salts”, as used herein, refers to derivatives of compounds of formula (I) wherein the parent compound is suitably modified by converting any of the free acid or basic group, if present, into the corresponding addition salt with any base or acid conventionally intended as being pharmaceutically acceptable.

[0032] Suitable examples of said salts may thus include mineral or organic acid addition salts of basic residues such as amino groups, as well as mineral or organic basic addition salts of acid residues such as carboxylic groups.

[0033] Cations of inorganic bases which can be suitably used to prepare salts comprise ions of alkali or alkaline earth metals such as potassium, sodium, calcium or magnesium.

[0034] Those obtained by reacting the main compound, functioning as a base, with an inorganic or organic acid to form a salt comprise, for example, salts of hydrochloric acid, hydrobromic acid, iodic acid, formic acid, benzoic acid, sulfuric acid, nitric acid, phosphoric acid, methane sulfonic acid, camphor sulfonic acid, nitric acid, acetic acid, oxalic acid, maleic acid, fumaric acid, succinic acid, p-toluenesulfonic acid, trifluoroacetic acid, 2-naphthoic acid, tartaric acid, l-hydroxy-2- naphthoic acid, naphthalene-2,7-disulfonic acid and citric acid.

[0035] The term "solvate" means a physical association of a compound of this invention with one or more solvent molecules, whether organic or inorganic. This physical association includes hydrogen bonding. In certain instances, the solvate might be isolated by crystallization, for example, when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. The solvate may comprise either a stoichiometric or non-stoichiometric amount of the solvent molecules.

[0036] The term "stereoisomer" refers to isomers of identical constitution that differ in the arrangement of their atoms in space. Enantiomers and diastereomers are examples of stereoisomers.

[0037] The term "enantiomer" refers to one of a pair of molecular species that are mirror images of each other and are not superimposable.

[0038] The term "diastereomer " refers to stereoisomers that are not mirror images.

[0039] When one of the compounds of this invention is defined as a specific enantiomer or diastereoisomer, the number reported in the name of this specific enantiomer or diastereoisomer is intended to define the order of elution of the compound during any process of chiral separation. For example, a compound defined as “Diastereoisomer 1” is intended to be the first eluted compound in the described chiral separation process.

[0040] In case of separation of 4 diastereoisomers by two different chromatographic methods, a compound defined as “Diastereoisomer 1” is intended to be the first eluted compound in the first chiral separation mentioned, while a compound defined as “Diastereoisomer 3” is intended to be the first eluted compound in the second chiral separation mentioned.

[0041] The term "racemate" or "racemic mixture" refers to a composition composed of equimolar quantities of two enantiomeric species, wherein the composition is devoid of optical activity.

[0042] The symbols "R" and "S" represent the configuration of substituents around a chiral carbon atom(s) and are intended to be used as defined in the literature (IUPAC Recommendations 1996, Pure and Applied Chemistry, 68:2193-2222 (1996)).

[0043] The term "tautomer" refers to each of two or more isomers of a compound that exist together in equilibrium and are readily interchanged by migration of an atom or group within the molecule.

[0044] The term "deuterium" refers to the isotopic deuterium of hydrogen (H).

[0045] The term "deuterated" refers to the case where the hydrogen atoms on an alkyl, cycloalkyl, aryl, heteroaryl group are substituted by at least one isotopic deuterium, with the upper limit of the number of deuterium substituents being equal to the sum of the number of hydrogen atoms that can be substituted. Unless otherwise indicated, the number of deuterium substituents is any integer between 1 and said upper limit, preferably substitution by 1 to 20 deuterium atoms, more preferably 1 to 10 deuterium atoms, more preferably 1 to 6 deuterium atoms, and further preferably 1 to 3 deuterium atoms.

[0046] The term “halogen” or “halogen atoms” or “halo” as used herein includes fluorine, chlorine, bromine and iodine atom.

[0047] The term “F” refers to fluorine.

[0048] The term "(Cx-Cy)alkyl" wherein x and y are integers, refers to a straight or branched chain alkyl group having from x to y carbon atoms. Thus, when x is 1 and y is 6, for example, the term includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl and n- hexyl.

[0049] The term “(Cx-Cy)haloalkyl” wherein x and y are integers, refers to the above defined “(Cx- Cy)alkyl” groups wherein one or more hydrogen atoms are replaced by one or more halogen atoms, which can be the same or different. Examples of said “(Cx-Cy)haloalkyl” groups may thus include halogenated, poly-halogenated and fully halogenated alkyl groups, wherein all hydrogen atoms are replaced by halogen atoms, e.g. trifluoromethyl.

[0050] The term “partially unsaturated” refers to a ring moiety that includes at least one double or triple bond. The term “partially unsaturated” is intended to encompass rings having multiple sites of unsaturation but is not intended to include aryl or heteroaryl moieties, as herein defined.

[0051] The term “(Cx-Cy)cycloalkyl” wherein x and y are integers, refers to saturated or partially unsatured mono- or poly-cyclic hydrocarbon groups containing the indicated number of ring carbon atoms. Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl.

[0052] The term “(Cx-Cy)heterocycloalkyl” wherein x and y are integers, refers to saturated or partially unsaturated monocyclic or polycyclic groups containing the indicated number of ring carbon atoms in which at least one ring carbon atom is replaced by at least one heteroatom or hetero-group (e.g. N, NH, S or O) or may bear an oxo (=0) substituent group. The said heterocycloalkyl (i.e. heterocyclic radical or group) might be further optionally substituted on the available positions in the ring, namely on a carbon atom, or on a heteroatom or hetero-group available for substitution. Substitution on a carbon atom includes spiro di -substitution as well as substitution on two adjacent carbon atoms, in both cases thus forming an additional condensed 5- to 6-membered heterocyclic ring. Non limiting examples of “(Cx-Cy)heterocycloalkyl” are represented by morpholinyl, pyrrolidinyl, piperazinyl, piperidinyl, azetidinyl, thiomorpholinyl, pyrrolinyl, dihydro- or tetrahydro-thiazolyl, oxetanyl, tetrahydropyranyl, pyranyl, dihydro- or tetrahy dro-furanyl .

[0053] The term “aryl” refers to mono- or bi-cyclic carbon ring systems wherein the ring is aromatic. Examples of suitable aryl ring systems include, for instance, phenyl or naphthyl. The term “heteroaryl” refers to mono- or bi- or tri-cyclic ring systems with 5 to 20, preferably from 5 to 15 ring atoms, in which at least one ring is aromatic and in which at least one ring atom is a heteroatom (e.g. N, NH, S or O). Examples of “heteroaryl” include thiophenyl, pyrrolyl, pyrazolyl, imidazolyl, isoxazolyl, oxazolyl, isothiazolyl, thiazolyl, pyridinyl, pyrimidinyl, pyrazinyl, benzofuranyl, dihydrobenzofuranyl, triazinyl.

[0054] A group may be optionally substituted, wherein the term “optionally substituted” refers to being substituted or unsubstituted. When the term "one or more " refers to any atoms or groups as substituents of the groups of the compound of formula (I), it is intended that from 1 to 3, preferably 1 to 2, more preferably 1 of such substituents may replace hydrogens on such variables.

[0055] A bond pointing to a wavy or squiggly line, such as as used in structural formulas herein, depicts the bond that is the point of attachment of the moiety or substituent to the core or backbone structure.

[0056] The term "bond" used to define a substituent refers to the situation where the two functional groups which the substituent is connected to are directly linked to each other with no additional atoms in between.

[0057] The carbonyl group is herein preferably represented as -(CO)- as an alternative to the other common representations such as -CO-, C=O, -C(O)- or -C(=O)-.

[0058] A dash (“-”) that is not between two letters or symbols is meant to represent the point of attachment for a substituent.

[0059] Whenever basic amino or quaternary ammonium groups are present in the compounds of formula (I), pharmaceutically acceptable anions may be present, selected among chloride, bromide, iodide, trifluoroacetate, formate, sulfate, phosphate, methanesulfonate, nitrate, maleate, acetate, citrate, fumarate, tartrate, oxalate, succinate, benzoate, p-toluenesulfonate, pamoate, emipamoate, xinafoate and naphthalene disulfonate.

[0060] Likewise, in the presence of acidic groups, such as for instance COOH groups, corresponding pharmaceutically acceptable cations may be present, for instance including alkaline or alkaline earth metal ions, including sodium, potassium, calcium and the like.

[0061] The term “ICso” refers to the half maximal inhibitory concentration as a measure of the potency of a substance in inhibiting a specific biological or biochemical function.

[0062] The term “pICso” refers to the negative logarithm of the ICso value expressed as molar concentration.

[0063] The term “PHGDH” or “phosphoglycerate dehydrogenase”, is alternatively referred to as 3- PGDH, 3PGDHm HEL-S-113, NLS, PDG, PGAD, PGD, PGDH, PHGDHD, or SERA. The term “PHGDH” encompasses mutants, variants, homologs, fragments, and synthetically modified phosphoglycerate dehydrogenases.

[0064] The term “treating”, or “treatment” of a disease state includes: (i) inhibiting the disease state, i.e. arresting the development of the disease state or its clinical symptoms, or (ii) relieving the disease state, i.e. causing temporary or permanent regression of the disease state or its clinical symptoms.

[0065] The term “preventing”, or “prevention” of a disease state includes causing the clinical symptoms of the disease state not to develop in a subject that may be exposed to or predisposed to the disease state but does not yet experience or display symptoms of the disease state. For example, treating or preventing a respiratory disease or disorder includes treating or preventing the symptoms the disorder such as cough and / or urge to cough associated with a respiratory disease.

[0066] The term “therapeutically effective amount” means an amount of a compound that, when administered to a subject for treating a disease state, is sufficient to affect such treatment for the disease state. The "therapeutically effective amount" will vary depending on the compound, disease state being treated, the severity or the disease treated, the age and relative health of the subject, the route, and form of administration.

[0067] The terms "fibrosis" or "fibrotic disorder," as used herein, refers to conditions that are associated with the abnormal accumulation of cells and / or fibronectin and / or collagen and / or increased fibroblast recruitment and include but are not limited to fibrosis of individual organs or tissues such as the heart, kidney, liver, joints, lung, pleural tissue, peritoneal tissue, skin, cornea, retina, musculoskeletal and digestive tract.

[0068] As above indicated, the present invention relates to compounds of formula (I) which are inhibitors of the PHGDH receptor and demonstrate desirable characteristics in vitro and in vivo that make them suitable for the prevention and / or treatment of fibrosis, preferably idiopathic pulmonary fibrosis (IPF).

[0069] In particular, the present invention relates to PHGDH inhibitors of general formula (I), or pharmaceutically acceptable salts thereof, to be used for the prevention and / or treatment of fibrosis or fibrotic conditions.

[0070] As used herein, the term “inhibitor” is defined as a compound that binds to and / or inhibits PHGDH with measurable affinity. In certain embodiments, an inhibitor has an IC50 and / or binding constant of less than about 100 pM, less than about 50 pM, less than about 1 pM, less than about 500 nM, less than about 100 nM, less than about 10 nM, or less than about 1 nM. In other embodiments, an inhibitor has a pIC50 on phenotypic assays of 5.5, or between 5.5 and 6.5, or higher than 6.5.

[0071] The compounds of formula (I) of the present invention are able to act as inhibitors of PHGDH receptor in a substantive and effective way, particularly appreciated by the skilled person when looking at a suitable and efficacious compound useful for the treatment of many disorders associated with fibrosis, and in particular the treatment of idiopathic pulmonary fibrosis (IPF).

[0072] As indicated in the Experimental part, the antifibrotic activity of the compounds of formula (I) has been monitored measuring the expression of fibrotic mediators, such as for example alpha smooth muscle actin (a-SMA).

[0073] As can be appreciated in Table 18, the compounds of formula (I) are able not only to reduce the fibroblast to myofibroblast transition (FMT) induced by TGF-P, but also to inhibit the release of a-SMA in NHLF treated with TGF-P (10 ng / ml). In this respect, all the tested compounds, dose- dependently, reduce the expression of a-SMA, after 72 hours of incubation.

[0074] The antifibrotic activity of compounds of formula (I) has been demonstrated also measuring the expression collagen I (Col-I), known fibrotic mediator, in Fibroblast to myofibroblast transition (FMT)in in vitro assay. Furthermore, collagen is a downstream effector of the PHGDH pathway, its inhibition underlines the key role of this marker in fibrosis processes.

[0075] As reported in the Table 18, the tested compounds dose-dependently inhibit the collagen I deposition, after 72h of treatment.

[0076] These findings suggest that de novo synthesis of serine and glycine is required for pulmonary fibrosis; the inhibition of myofibroblast differentiation and collagen deposition is strongly correlated and necessary for the antifibrotic activity of the compounds.

[0077] As further advantage, the compounds of the present invention may result efficacious also in the Bleomycin-induced pulmonary fibrosis in mice. Bleomycin-induced pulmonary fibrosis in mice is the most commonly applied in vivo experimental model to induce lung fibrosis. Instillation of Bleomycin in the trachea induces a multiphasic response that starts with an acute and severe inflammation followed by a diffuse matrix and collagen deposition that led to histological changes, with evident fibrosis accumulation and loss of functional parenchymal tissue, replicating certain pathological features consistent with those observed in the lungs of IPF patients.

[0078] Indeed, the bleomycin animal model is widely used in the assessment of potential antifibrotic agents.

[0079] More advantagously, beyond the inhibitory property versus PHGDH, the compounds of the present invention are also endowed with a suitable BSEP profile, that is relevant for the progression of any oral drug candidate.

[0080] Liver toxicity is a relatively frequent finding during preclinical safety testing in animals and is an important cause of compound attrition prior to clinical trials (Waring, M.J. et al. Nat. Rev. Drug Discov. 14, 475-486 (2015)).

[0081] Bile salt export pump (BSEP) inhibition has emerged as an important mechanism that may contribute to the initiation of human drug-induced liver injury (DILI), and it should be considered alongside other mechanisms when evaluating possible DILI risk because is essential for normal bile flow and healthy liver function. Proactive evaluation and understanding of BSEP inhibition is recommended in drug discovery and development to aid internal decision making on potential human DILI risk. (J. G. Kenna, CLINICAL PHARMACOLOGY & THERAPEUTICS, 104, 5, 916-932 (2018))

[0082] The bile salt export pump (BSEP) is an efflux transporter located on the canalicular membrane of hepatic cells and is the primary transporter of bile acids from the hepatocyte to the biliary system. Together with other hepatic transporters of uptake and efflux, it is involved in the homeostasis of bile salts.

[0083] In the last decade, BSEP inhibition has emerged as an important mechanism that may contribute to the initiation of human drug-induced liver injury and therefore it is important to consider BSEP inhibition alongside when considering the risk of possible acute drug-induced liver failure.

[0084] Of note, the compounds of formula (I) of the present invention are characterized by an in vitro BSEP inhibition at 100 pM < 50 % that can be considered suitable and acceptable from a safety point of view, as shown in Table 19.

[0085] Even more advantageously, the compounds of formula (I) of the present invention are also endowed with a good permeability profile that, in its turn, can ensure a suitable bioavailability for an oral administration.

[0086] The permeability was assessed in human Caco-2 cell line, an in vitro model that mimic human gastrointestinal barrier and so useful to predic oral absorption. A passive permeability value > 15 nm / sec is considered suitable for an oral administration, as shown in Table 20.

[0087] Compounds of formula (I) of the invention, comprising a small linear chain with two carbon atoms and a final ORi group in position alpha to the COORe group, or eventually with Ri and Rz fused together to form a -(Ce-Cvjheterocycloalkyl, leads unexpectedly to a series of compounds that is active for IPF in the phenotypic assay, endowed with a very good BSEP and permeability profile, thus are suitable for treatment of fibrosis with a very promising bioavailability profile for oral administration.

[0088] As indicated in the Experimental part, in Comparative Examples Results Section, conversely to Comparative Example A, characterized by a small linear chain with two carbon atoms and a final morpholino group in position alpha to the carboxyl group, and conversely to Comparative Example B, characterized by a small linear chain with three carbon atoms and a final ORi group in position alpha to carboxylic acid, and conversely to Comparative Example C, characterized by a small branched chain with three carbon atoms and by the absence of a final ORi group in position alpha to carboxylic acid, the presence of a small linear chain with two carbon atoms and final ORi group in position alpha to the COORe group, with Ri and R2 eventually fused together to form a - (C6-C7)heterocycloalkyl, leads unexpectedly to a series of compounds of formula (I) that is active for IPF in the phenotypic assay, endowed with a very good BSEP inhibition and permeability profile, thus suitable for treatment of fibrosis with a very promising bioavailability profile for oral administration.

[0089] The state of the art does not describe or suggest derivatives of general formula (I) of the present invention having inhibitory activity on PHGDH which demonstrate good results in assays for the prevention and / or treatment of fibrosis, in particular IPF, and at the same time a suitable BSEP profile and a good permeability.

[0090] Accordingly, the compounds of formula (I) can be used in the oral treatment of fibrosis, and in particular treatment of idiopathic pulmonary fibrosis, whenever PHGDH receptors are involved.

[0091] In a first aspect the invention refers to a compound of formula (I) wherein

[0092] Ri is -(Ci-Ce)alkyl;

[0093] Rz is H or -(Ci-Ce)alkyl, optionally substituted with OR7, or Ri and Rz are fused together to form a -(C6-C7)heterocycloalkyl;

[0094] R3 is halogen;

[0095] R4 and R5 are independently H or selected from the group consisting of halogen, -OR7 and - (Ci-Ce)alkyl;

[0096] Re and R7 are independently H or -(Ci-Ce)alkyl; and pharmaceutically acceptable salts thereof.

[0097] All the listed groups for each of the variable moieties Ri, Rz, R3, Ri, Rs, Re and R7 of the compounds of the invention have to be intended as alternatives and may be combined with each other in embodiments which are included in the scope of the invention.

[0098] In one embodiment Ri is -(Ci-Ce)alkyl. In a preferred embodiment, Ri is -(Ci-C4)alkyl. In a more preferred embodiment, Ri is methyl. In one embodiment, R2 is H or -(Ci-Ce)alkyl, optionally substituted with OR7. In a preferred embodiment, R2 is H. In another preferred embodiment, R2 is -(Ci-C4)alkyl, optionally substituted with OR7. In a more preferred embodiment, Rz is H or ethyl, optionally substituted with -OMe.

[0099] In one embodiment, Ri and Rz are fused together to form a -(C6-C7)heterocycloalkyl. In a more preferred embodiment, Ri and Rz are fused together to form a tetrahydropyrane.

[0100] In one embodiment, R3 is halogen, selected among chlorine, bromine, iodine, fluorine. In a preferred embodiment, R3 is chlorine.

[0101] In one embodiment, R4 and R5 are independently H or selected from the group consisting of halogen, -OR7 and -(Ci-Ce)alkyl. In a preferred embodiment, R4 and R5 are independently H or selected from the group consisting of halogen, -OR7 and -(Ci-C4)alkyl. In a more preferred embodiment, R4 and R5 are independently H or selected from the group consisting of chlorine, fluorine, methoxy and methyl.

[0102] In one preferred embodiment, R4 and R5 are H. In another preferred embodiment, R4 and R5 are halogen. In another preferred embodiment, R4 and R5 are -OR7. In another preferred embodiment, R4 and R5 are -(Ci-C4)alkyl.

[0103] In one embodiment, Re and R7 are independently H or -(Ci-Ce)alkyl. In a preferred embodiment, Re and R7 are independently H or -(Ci-C4)alkyl. In a more preferred embodiment, Re and R7 are independently H or methyl.

[0104] In a preferred embodiment, the present invention refers to a compound of formula (I) wherein Reis H, represented in the formula (la): wherein

[0105] Ri is -(Ci-Ce)alkyl;

[0106] Rz is H or -(Ci-Ce)alkyl, optionally substituted with OR7, or Ri and Rz are fused together to form a -(Ce-C7)heterocycloalkyl;

[0107] R3 is halogen;

[0108] R4 and R5 are independently H or selected from the group consisting of halogen, -OR7 and - (Ci-Ce)alkyl;

[0109] R7 is H or -(Ci-Ce)alkyl; and pharmaceutically acceptable salts thereof.

[0110] In a more preferred embodiment, the present invention refers to a compound of formula (I) wherein R3 is chlorine and Re is H, represented in the formula (lb):

[0111] Wherein:

[0112] Ri is -(Ci-Ce)alkyl;

[0113] Rz is H or -(Ci-Ce)alkyl, optionally substituted with OR7, or Ri and Rz are fused together to form a -(C6-C7)heterocycloalkyl;

[0114] R4 and R5 are independently H or selected from the group consisting of halogen, -OR7 and - (Ci-Ce)alkyl;

[0115] R7 is H or -(Ci-Ce)alkyl; and pharmaceutically acceptable salts thereof.

[0116] In a more preferred embodiment, the present invention refers to a compound of formula (I) or compound of formula (la) or compound of formula (lb), wherein:

[0117] Ri is methyl;

[0118] Rz is H or ethyl, optionally substituted with OR7; or Ri and Rz are fused together to form a tetrahydropyrane.

[0119] In a more preferred embodiment, the present invention refers to a compound of formula (I) or compound of formula (la) or compound of formula (lb), wherein:

[0120] R4 and R5 are independently H or selected from the group consisting of chlorine, fluorine, methoxy and methyl;

[0121] R7 is H or methyl; and pharmaceutically acceptable salts thereof.

[0122] In an even more preferred embodiment, the present invention refers to a compound of formula (I) or formula (la) or formula (lb), wherein:

[0123] Ri is methyl;

[0124] R2is H, or Ri and Rz are fused together to form a tetrahydropyrane;

[0125] R4 and R5 are independently H or selected from the group consisting of methyl and -OR7; R? is methyl; and pharmaceutically acceptable salts thereof.

[0126] All the preferred groups listed above for each of the variable moieties Ri, Rz, Rj, Rt, Rs, Re and R7 of the compounds of the invention may be combined with each other in embodiments which are included in the scope of the invention.

[0127] In a more preferred embodiment, the invention refers to at least one of the compounds listed in Table 1 below and pharmaceutically acceptable salts thereof.

[0128] Table 1 - List of preferred compounds

[0129] It is to be understood that all the single deuterates, enantiomers, diastereoisomers and mixtures thereof, in any proportion, or pharmaceutically acceptable salts and solvates of the compounds of formula (I) are encompassed within the scope of the present invention.

[0130] In another embodiment, the invention refers to a compound of formula (I) as PHGDH inhibitor suitable for oral administration useful for the prevention and / or treatment of fibrosis, in particular IPF. In this respect, it has been found that the compounds of formula (I) of the present invention have antifibrotic activity, monitored measuring the expression of a-SMA in Phenotypic assay, expressed as pICso, equal or higher than 5. Preferably, the compounds of the present invention have a pICso on a-SMA in phenotypic assay between 5 and 5.5. More preferably, the compounds of the present invention have a pICso higher than5.5.

[0131] The compounds of the present invention are also characterized by an in vitro BSEP inhibition at 100 pM < 50 %, that can be considered suitable and acceptable from a safety point of view, and by a passive permeability value > 15 nm / sec, which is considered suitable for an oral administration. Preferably, compounds showed BSEP inhibition values between 50 and 25%. More preferably, compounds showed BSEP inhibition values between 25 and 13%; most preferably, compounds showed BSEP inhibition at 100 pM below 13%. The present invention also refers to a pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, in admixture with at least one or more pharmaceutically acceptable carrier and / or excipient.

[0132] As used herein, "effective amount" in reference to a compound of formula (I) or a pharmaceutically acceptable salt thereof or other pharmaceutically active agent means an amount of the compound sufficient to treat the patient's condition but low enough to avoid serious side effects and it can nevertheless be routinely determined by the skilled artisan.

[0133] The compounds of formula (I) may be administered once or according to a dosing regimen wherein a number of doses are administered at varying intervals of time for a given period of time. Typical daily dosages may vary depending upon the route of administration chosen.

[0134] In one embodiment, the invention refers to a pharmaceutical composition of compounds of formula (I) in admixture with one or more pharmaceutically acceptable carrier or excipient, for example those described in Remington’s Pharmaceutical Sciences Handbook, XVII Ed., Mack Pub., N.Y., U.S.A.

[0135] In therapeutic use, the compound of formula (I) may be administered by any convenient, suitable, or effective route. Administration of the compounds of the invention and their pharmaceutical compositions may be accomplished according to patient needs, for example, orally, nasally, parenterally (subcutaneously, intravenously, intramuscularly, intrastemally and by infusion) and by inhalation.

[0136] Preferably, the compounds of the present invention are administered orally or by inhalation.

[0137] In a more preferred embodiment, the compounds of the present invention or their pharmaceutical compositions are administered orally.

[0138] In another preferred embodiment, the compounds of the present invention or their pharmaceutical compositions are administered by inhalation.

[0139] In one preferred embodiment, the pharmaceutical composition comprising the compound of formula (I) is a solid oral dosage form such as tablets, gel caps, capsules, caplets, granules, lozenges and bulk powders.

[0140] The compounds of the invention can be administered alone or combined with various pharmaceutically acceptable carriers, diluents (such as sucrose, mannitol, lactose, starches) and known excipients, including suspending agents, solubilizers, buffering agents, binders, disintegrants, preservatives, colorants, flavorants, lubricants and the like.

[0141] In a further embodiment, the pharmaceutical composition comprising a compound of formula (I) is a liquid oral dosage form such as aqueous and non-aqueous solution, emulsion, suspension, syrup. Such liquid dosage form can also contain suitable known inert diluents such as water and suitable known excipients such as preservatives, wetting agents, sweeteners, flavorants, as well as agents for emulsifying and / or suspending the compounds of the invention.

[0142] In a further embodiment, the pharmaceutical composition comprising the compound of formula (I) is an inhalable preparation such as inhalable powders, propellant-containing metering aerosols or propellant-free inhalable formulations.

[0143] Inhalable preparations include inhalable powders, propellant-containing metering aerosols or propellant-free inhalable formulations and may be administered through a suitable inhalation device which may be respectively selected from dry powder inhaler, pressurized metered dosed inhaler, or a nebulizer.

[0144] In another embodiment the invention is also directed to a device comprising a pharmaceutical composition comprising a compound of formula (I) according to the invention, or a pharmaceutically acceptable salt thereof, obtained as described above according to the invention, in form of a single- or multi-dose dry powder inhaler or a metered dose inhaler.

[0145] For administration as a dry powder, single- or multi-dose inhalers known from the prior art may be utilized. In that case the powder may be filled in gelatine, plastic or other capsules, cartridges, or blister packs or in a reservoir.

[0146] A diluent or carrier, chemically inert to the compounds of the invention, e.g. lactose or any other additive suitable for improving the respirable fraction, may be added to the powdered compounds of the invention.

[0147] Inhalation aerosols containing propellant gas such as hydrofluoroalkanes may contain the compounds of the invention either in solution or in dispersed form. The propellant-driven formulations may also contain other ingredients such as co-solvents, stabilizers, and optionally other excipients.

[0148] The propellant-free inhalable formulations comprising the compounds of the invention may be in form of solutions or suspensions in an aqueous, alcoholic or hydroalcoholic medium and they may be delivered by j et or ultrasonic nebulizers known from the prior art or by soft-mist nebulizers.

[0149] The compounds of the invention can be administered as the sole active agent or in combination with other pharmaceutical active ingredients.

[0150] The dosages of the compounds of the invention depend upon a variety of factors including among others the particular disease to be treated, the severity of the symptoms, the route of administration and the like.

[0151] In a further aspect, the invention refers to the use of the compounds of formula (I) for the preparation of a medicament. In another aspect, the present invention refers to a compound of formula (I) for use as a medicament. Thus, the invention refers to a compound of formula (I) in the preparation of a medicament, preferably for use in the treatment of disorders associated with 3 -phosphoglycerate dehydrogenase (PHGDH) receptors mechanism.

[0152] In a further embodiment, the present invention refers to a compound of formula (I) for use in the prevention and / or treatment of diseases, disorders or conditions associated with dysregulation of PHGDH.

[0153] In one aspect, the invention also refers to a method for the prevention and / or treatment of disorders associated with PHGDH receptors mechanisms, said method comprising administering to a patient in need of such treatment a therapeutically effective amount of a compound of formula (I).

[0154] In one embodiment, the present invention refers to a compound of formula (I) useful for the prevention and / or treatment of fibrosis and / or diseases, disorders, or conditions that involve fibrosis.

[0155] In a preferred embodiment, the present invention is directed to the compounds of formula (I) for use for the prevention and / or treatment of a fibrotic disease.

[0156] In another embodiment, the present invention provides a method for preventing and / or treating fibrotic diseases, the method comprising administering a compound of formula (I).

[0157] In another embodiment, the present invention provides a method for preventing and / or treating fibrotic diseases, the method comprising administering a pharmaceutical composition comprising the compounds of formula (I).

[0158] In another aspect, the present invention is directed to a pharmaceutical composition comprising the compounds of formula (I) and one or more pharmaceutically acceptable carriers and / or excipients, for use for the prevention and / or treatment of fibrotic diseases.

[0159] In a further aspect, the fibrotic diseases mentioned above are selected from pulmonary fibrosis, idiopathic pulmonary fibrosis (IPF), hepatic fibrosis, sarcoidosis, familiar pulmonary fibrosis, chronic hypersensitivity pneumonitis (CHP), kidney or renal fibrosis, ocular fibrosis, cardiac fibrosis, arterial fibrosis and systemic sclerosis.

[0160] Preferably, the compounds of formula (I) of the present invention are useful for the treatment and / or prevention of fibrosis such as pulmonary fibrosis, idiopathic pulmonary fibrosis (IPF), hepatic fibrosis, sarcoidosis, familiar pulmonary fibrosis, chronic hypersensitivity pneumonitis (CHP), kidney or renal fibrosis, ocular fibrosis, cardiac fibrosis, arterial fibrosis and systemic sclerosis.

[0161] In another embodiment, the invention refers to the use of the compound of formula (I) or its pharmaceutical composition for the preparation of a medicament for the treatment and / or prevention of pulmonary fibrosis, idiopathic pulmonary fibrosis (IPF), hepatic fibrosis, sarcoidosis, familiar pulmonary fibrosis, chronic hypersensitivity pneumonitis (CHP), kidney or renal fibrosis, ocular fibrosis, cardiac fibrosis, arterial fibrosis and systemic sclerosis.

[0162] In another embodiment, the invention refers to a compound of formula (I) or a pharmaceutical composition for use in the prevention and / or treatment of fibrotic disease, wherein the fibrotic disease is selected from: pulmonary fibrosis, idiopathic pulmonary fibrosis (IPF), hepatic fibrosis, sarcoidosis, familiar pulmonary fibrosis, chronic hypersensitivity pneumonitis (CHP), kidney or renal fibrosis, ocular fibrosis, cardiac fibrosis, arterial fibrosis and systemic sclerosis.

[0163] In another embodiment, the invention refers to a method for the treatment and / or prevention of fibrotic diseases selected from the group consisting of pulmonary fibrosis, idiopathic pulmonary fibrosis (IPF), hepatic fibrosis, sarcoidosis, familiar pulmonary fibrosis, chronic hypersensitivity pneumonitis (CHP), kidney or renal fibrosis, ocular fibrosis, cardiac fibrosis, arterial fibrosis and systemic sclerosis, the method comprising administering a compound of formula (I) or a pharmaceutical composition comprising a compound of formula (I) and one or more pharmaceutically acceptable carriers and / or excipients.

[0164] More preferably, the compounds of formula (I) of the present invention are useful for the treatment of idiopathic pulmonary fibrosis (IPF).

[0165] In a more preferred embodiment, the fibrotic disease mentioned above is IPF.

[0166] In another preferred embodiment, the invention refers to a compound of formula (I) or its pharmaceutical composition for use in the prevention and / or treatment of IPF.

[0167] In another preferred embodiment, the invention refers to the use of the compounds of formula (I) or its pharmaceutical composition for the preparation of a medicament for the treatment and / or prevention of IPF.

[0168] In another preferred embodiment, the invention refers to a method for the treatment and / or prevention of IPF, the method comprising administering a compound of formula (I) or a pharmaceutical composition comprising a compound of formula (I) and one or more pharmaceutically acceptable carriers and / or excipients.

[0169] Any suitable route of administration may be employed for providing a mammal, especially a human, with an effective dosage of the compound of formula (I).

[0170] The magnitude of prophylactic or therapeutic dose of the compound of formula (I) will, of course, vary with the nature of the severity of the condition to be treated and with its route of administration, and will generally be determined by clinical trial as required in the pharmaceutical art. It will also vary according to the age, weight and response of the individual patient.

[0171] All preferred groups or embodiments described above for compounds of formula (I) may be combined with each other and apply as well mutatis mutandis. PREPARATIONS OF INTERMEDIATES AND EXAMPLES

[0172] Chemical Names of the compounds were generated with Structure To Name Enterprise 10.0 Cambridge Software or are common chemical names. All reagents, for which the synthesis is not described in the experimental part, are either commercially available, or are known compounds or may be formed from known compounds by known methods by a person skilled in the art.

[0173] In the procedures that follow, some of the starting materials are identified through an “Intermediate” or “Example” number with indications on step number. This is provided merely for assistance to the skilled chemist.

[0174] When reference is made to the use of a “similar” or “analogous” procedure, as it will be appreciated by those skilled in the art, such a procedure may involve minor variations, for example reaction temperature, reagent / solvent amount, reaction time, work-up conditions or chromatographic purification conditions, that will be appreciated by those skilled in the art.

[0175] List of Abbreviations

[0176] 1H-NMR: Proton nuclear magnetic resonance;

[0177] 2-MeTHF : 2-methyltetrahydrofuran;

[0178] AA powder: (L-Asp acid; L-Asparagin; L-Glutamic acid; Hydroxy L-Proline; L-Proline); ab.: antibody;

[0179] ACN: acetonitrile;

[0180] ACN-d3 : deuterated acetonitrile;

[0181] AcOH: Acetic acid;

[0182] AIBN: azobisisobutyronitrile;

[0183] AUC: area under the curve;

[0184] Bn: benzyl;

[0185] Boc: tert-butyl oxy carbonyl;

[0186] BOC2O: Di-tert-butyl dicarbonate;

[0187] BSA: Bovine Serum Albumin; c.a.: commercially available;

[0188] CDC13 : deuterated chloroform;

[0189] Clnii: biliary clearance;

[0190] CV: Column Volumes; dba: dibenzylideneacetone;

[0191] DCE: 1,2-di chloroethane;

[0192] DCM: Dichloromethane; de: diastereomeric excess;

[0193] DIAD: diisopropyl azodicarboxylate; DIBAL-H: Diisobutylaluminium hydride;

[0194] DIPEA: N,N-Diisopropylethylamine;

[0195] DMA: dimethylacetamide;

[0196] DMAP: 4-dimethylaminopyridine;

[0197] DMEM: Dulbecco's Modified Eagle Medium;

[0198] DMF : N,N-Dimethylformamide;

[0199] DMSO: Dimethylsulfoxide;

[0200] DMSO-d6: deuterated dimethyl sulfoxide; ee: enantiomeric excess; eq.: equivalents;

[0201] EtOAc: Ethyl acetate;

[0202] FBS: Fetal Bovine Serum;

[0203] FCC: Flash column chromatography; h: hour / s;

[0204] HATU: l-[Bis(dimethylamino)methylene]-lH-l,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate);

[0205] HPLC: high pressure liquid chromatography;

[0206] HPLC-MS / MS: high pressure liquid chromatography-mass spectrometry / mass spectrometry;

[0207] LCMS: Liquid chromatography-mass spectrometry;

[0208] LDA: lithium diisopropylamide;

[0209] LG: leaving group;

[0210] LiHMDS: Lithium bis(trimethylsilyl)amide;

[0211] MEM: Minimal Essential Medium;

[0212] MeOH: methyl alcohol; min: minute / s;

[0213] MPLC: medium-pressure liquid chromatography;

[0214] Ms: mesyl (MsCl: mesylchloride);

[0215] NaHMDS: sodium bis(trimethylsilyl)amide;

[0216] NCE: new chemical entity;

[0217] NHLF : Normal Human Lung Fibroblast;

[0218] NMR: nuclear magnetic resonance; on: overnight;

[0219] P / S: Penicillin-Streptomycin;

[0220] PBS: Phosphate Buffered Saline; Pd2(dba)s: Tris(dibenzylideneacetone)dipalladium(0); pen / strep: Penicillin-streptomycin;

[0221] PGn: protecting group;

[0222] PgP: P -glycoprotein;

[0223] PTS: p-toluenesulfonic acid; r.t. : Retention time;

[0224] RT : Room temperature; sat aq: saturated aqueous;

[0225] SCX: strong cation exchange;

[0226] SDS: Sodium Dodecyl Sulfate;

[0227] SFC: supercritical fluid chromatography;

[0228] SFC-MS: supercritical fluid chromatography-mass spectrometry;

[0229] SN: nucleophilic substitution;

[0230] TBME: tert-Butyl methyl ether;

[0231] TBS: TRIS-buffered saline;

[0232] TEA: Triethylamine;

[0233] TFA: Trifluoroacetic acid;

[0234] TGFP: Transforming Growth Factor-B;

[0235] TGX-gel : Tris-Glycine extended- Gels;

[0236] THF: Tetrahydrofuran;

[0237] TLC: Thin-layer chromatography;

[0238] TsOH: p-toluenesulfonic acid;

[0239] UPLC®: Ultra Performance Liquid Chromatography;

[0240] XPhos: Dicyclohexyl[2',4',6'-tris(propan-2-yl)[l,l'-biphenyl]-2-yl]phosphane; a-SMA: alpha-smooth muscle actin;

[0241] General Synthetic Procedures

[0242] The compounds of the present invention can be prepared in a number of ways known to the one skilled in the art of organic synthesis. It will be understood that the functionality / s present on the molecule should be consistent with the transformation proposed. This will sometimes require a modification of the order of synthetic steps in order to obtain a desired compound of the invention. While the optimal reaction conditions may vary depending on the reactants or solvent used, such conditions can be readily determined by those skilled in the art by routine optimization procedures. Thus, processes described below should not be viewed as limiting the scope of the synthetic methods available for the preparation of the compounds of the invention. In some cases, generally known protective groups (PG) may be employed when needed to mask or protect sensitive or reactive moieties, in accordance with general principles of chemistry (Protective groups in organic syntheses, 3rd ed. T. W. Greene, P. G. M. Wuts).

[0243] The compounds of formula (I), including all the compounds here above listed, can be generally prepared according to the procedures outlined in Schemes shown below, wherein at least one non-limiting synthetic route is provided for the preparation of the exemplified compounds (i.e. the Examples).

[0244] Properly substituted lJT-indole-2-carboxylic acids of general formula (VI) can be prepared according to Scheme 1, through multi-step synthetic sequences starting from corresponding suitably substituted benzaldehydes of general formula (II). Such benzaldehydes can be converted into 2-azido-3 -phenylacrylates of general formula (III) by means of condensation reactions employing 2-azidoacetates, such as for example methyl 2-azidoacetates, ethyl 2-azidoacetates or others, in the presence of a base, such as for example metal alkoxides like sodium or lithium or potassium methoxide or ethoxide or others, in a suitable solvent, such as for example methanol or ethanol or others. 2-azido-3 -phenylacrylates (III) can be cyclized to yield indoles of general formula (IV), for example by heating at high temperatures in suitable solvents, such as for example xylene or others. Indoles (IV) can then be TV-alkylated to corresponding V-Me indoles of general formula (V) in the presence of suitable methylating agents, such as for example methyl halides, like methyl iodide or others, and of a base, such as for example a metal carbonate like potassium or sodium carbonate or others, in a suitable solvent, such as DMF, DMA, 1,4-di oxane or others or mixtures thereof. 1 -methyl- U / -indole-2-carboxylates (V) can be converted into corresponding 1- methyl- l / / -indole-2-carboxylic acids of general formula (VI) by ester function cleavage, for example by means of basic cleavage in the presence of metal hydroxides such as for example lithium, sodium, potassium or other hydroxides, in a suitable solvent or mixture of solvents, such as for example THF, methanol, ethanol, water or others or mixtures thereof. In some instances, Intermediates (IV) can be directly converted into Intermediates (VI) by two-step procedures in which crude Intermediates (V) are not purified nor fully characterized. Reagents to be used in such two-step procedures can be the same reagents employed in stepwise approach previously described. Scheme 1

[0245] Wherein R3, R4, Rs are defined as above.

[0246] Intermediate (VII) can be prepared according to WO2017-156165 and can then be converted into corresponding intermediate (VIII) according to Scheme 2. This can be accomplished through Pd-catalysed decarb oxy lative cross-couplings (see WO2017-156165). Alternatively, Intermediates (VIII) can be obtained by suitable Pd-catalysed cross-coupling reactions, such as for example Suzuki cross-couplings or others, with suitable alkylboronic acids or alkyl boronates or alkyl trifluoroborates or others, using a suitable Pd source, such for example Pd2(dba)s or others, and an appropriate Pd ligand, such as for example XPhos or others. Alternatively, Negishi crosscouplings can yield Intermediates (VIII) by using suitable alkyl-zinc reagents and using a suitable Pd source, such for example Pd2(dba)3 or others, and an appropriate Pd ligand, such as for example XPhos or others. Alkyl-zinc reagents can be prepared in a number of methods well known to those skilled in the art, starting for example from corresponding alkyl halides, such as for example alkyl bromides or others, bearing a carboxylic acid group suitably protected for example as an ester, such as for example a methyl ester, or an ethyl ester or a 'butyl ester or others. Intermediates (VIII) can then be transformed into Intermediates (IX) by alkylation in alpha to ester group. Such alkylation reactions can be promoted by a base, such as for example metal hydrides like NaH or others, or metal amides, such as for example LDA, LiHMDS, NaHMDS or others. Alkylating agents can be selected from suitably substituted mono-haloalkyls, such as for example alkylbromides or alkyliodides or others, giving rise to Intermediates (IX). Alternatively, suitably substituted di-haloalkyls, such as for example l,n-dibromides or l,n-diiodides (n=3-7) or others, can be used, thus giving rise to Intermediates (IX), where Ri and R2 are fused together to form a - (C6-C7)heterocycloalkyl. In another embodiment, other leaving groups instead of halides can be considered in such alkylation or double alkylation reaction, such as for example mesylates or others. Suitable solvents for the reaction converting Intermediates (VIII) into Intermediates (IX) can be selected for example from DMF, DMA, DMSO, THF, 1,4-di oxane or others, or mixtures thereof. Nitrile group in Intermediates (IX) can then be converted into amidic group of Intermediates (X) and subsequently to amine group of Intermediates (XI) by synthetic sequences described in WO2017-156165, or by methods well known to those skilled in the art.

[0247] Scheme 2

[0248] Wherein Ri, R2, Re are defined as above.

[0249] Single enantiomers (Vll-a) and (Vll-b) can be isolated from racemic Intermediate (VII) according to Scheme 3, by means of chiral separation techniques, such as chiral column chromatography or simulated moving bed chromatography or others. Enantiopure Intermediates (Vll-a) and (Vll-b) can then be converted into subsequent intermediates (Vlll-a) and (Vlll-b) according to Pd-catalysed decarb oxy lative cross-couplings. Alternatively, Intermediates (Vlll-a) and (Vlll-b) can be obtained by suitable Pd-catalysed cross-coupling reactions, such as for example Suzuki cross-couplings or others, reacting Intermediates (Vll-a) and (Vll-b) with suitable alkylboronic acids or alkyl boronates or alkyl trifluoroborates or others, using a suitable Pd source, such for example Pd2(dba)3 or others, and an appropriate Pd ligand, such as for example XPhos or others. Alternatively, Negishi cross-couplings can yield Intermediates (Vlll-a) and (Vlll-b) by reacting Intermediates (Vll-a) and (Vll-b) with suitable alkyl-zinc reagents and using a suitable Pd source, such for example Pd2(dba)3 or others, and an appropriate Pd ligand, such as for example XPhos or others. Alkyl-zinc reagents can be prepared in a number of methods well known to those skilled in the art, starting for example from corresponding alkyl halides, such as for example alkyl bromides or others, bearing a carboxylic acid group suitably protected for example as an ester, such as for example a methyl ester, or an ethyl ester or a 'butyl ester or others. Intermediates (VIII- a) and (Vlll-b) can then be transformed into corresponding Intermediates (IX-a) and (IX-b) by alkylation in alpha to ester group. Such alkylation reactions can be promoted by a base, such as for example metal hydrides like NaH or others, or metal amides, such as for example LDA, LiHMDS, NaHMDS or others. Alkylating agents can be selected from suitably substituted mono- haloalkyls, such as for example alkylbromides or alkyliodides or others, giving rise to Intermediates (IX-a) or (IX-b). Alternatively, suitably substituted di-haloalkyls, such as for example l,n-dibromides or l,n-diiodides (n=3-7) or others, can be used, thus giving rise to Intermediates (IX), where Ri and R2 are fused together to form a -(C6-C7)heterocycloalkyl. In another embodiment, other leaving groups instead of halides can be considered in such alkylation or double alkylation reaction, such as for example mesylates or others. Suitable solvents for the reaction converting Intermediates (VUI-a) or (Vlll-b) into corresponding Intermediates (IX-a) or (IX-b) can be selected for example from DMF, DMA, DMSO, THF, 1,4-di oxane or others, or mixtures thereof. Nitrile group in Intermediates (IX-a) and (IX-b) can then be converted into amidic group of corresponding Intermediates (X-a) and (X-b) and subsequently to amine group of corresponding Intermediates (Xl-a) and (Xl-b) by synthetic route described in WO2017-156165, or by methods well known to those skilled in the art.

[0250] It should be noted that Intermediates (IX-a), (IX-b) and following Intermediates can be obtained as enantiopure materials or as mixtures of diastereomers, depending on the nature of selected substituents.

[0251] Scheme 3

[0252] Wherein Ri, R2, Re are defined as above.

[0253] Accordingly, the present invention provides an Intermediate Compound (XI) having formula: wherein

[0254] Ri is -(Ci-Ce)alkyl; R2 is H or -(Ci-Ce)alkyl, optionally substituted with OR7, or Ri and Rz are fused together to form a -(C6-C7)heterocycloalkyl;

[0255] Re is H or -(Ci-Ce)alkyl; or the pharmaceutically acceptable salts thereof, for the preparation of the compound of formula (I).

[0256] In a preferred embodiment, the invention provides an Intermediate Compound (XI) or the pharmaceutically acceptable salts thereof, for the preparation of the compound of formula (I), having formula: wherein

[0257] Ri is methyl;

[0258] R2 is H or ethyl, optionally substituted with OR7; or Ri and Rz are fused together to form a tetrahydropyrane

[0259] Re is H.

[0260] The invention further provides the use of the intermediate compound (XI) as defined above in the preparation of a compound of formula (I), or pharmaceutically acceptable salts thereof.

[0261] According to Scheme 4, properly substituted lJT-indole-2-carboxylic acids of general formula (VI), commercially available or prepared according to WO2017-156165 or to Scheme 1, can be condensed to Intermediates (XI) or (Xl-a) or (Xl-b), as free amine or salts, through in situ activation of carboxylic acid function, for example as an acylchloride or by the use of coupling agents, such as for example HATU or others, and subsequent nucleophilic acyl substitution reaction in the presence of a base, such as for example DIPEA or TEA or others, in a suitable solvent, such as DMF, DMA, THF, DCM or others or mixtures thereof. Such condensation reaction yields Examples of formula (I). Examples of formula (la) can finally be obtained from Examples (I) by ester function cleavage, for example in acidic conditions in the presence of HC1 or TFA or other acids, or in basic conditions, in the presence of metal hydroxides such as for example Li+, Na+, K+or other hydroxides, in solvents such as THF, 1,4-di oxane, alcohols, water or mixtures thereof. Additionally, in cases where an Example is a mixture of stereoisomers, further Examples can be obtained from these by means of chiral separations techniques, well known from the skilled person, such as chiral column chromatography or others. Scheme 4

[0262] Alternatively, in cases where a final compound (la) is a mixture of stereoisomers, further Examples can be obtained from it by means of separation of stereoisomers through a sequence of transformations, such as for example the conversion of mixture of stereoisomers of formula (la) into Intermediates (XII) by introduction of chiral auxiliaries, such as for example chiral oxazolidin- 2-ones, followed by the isolation of single stereoisomers (Xll-a) and (XILb) from Intermediates (XII), such as for example by means of chromatographic separations, and final removal of chiral auxiliary, as depicted in Scheme 4a.

[0263] Scheme 4a

[0264] Wherein Ri, R2, R3, R4, Rs, Re are defined as above.

[0265] Exemplified preparation processes are given in the following experimental part. General Experimental Details

[0266] Purifications

[0267] Purification by “chromatography”, “flash chromatography” or “flash column chromatography (FCC)” refers to purification using a Biotage, or Interchim puriFlash purification system, or equivalent MPLC system using a pre-packed polypropylene column containing stationary phase (cartridge). Where products were purified using an Si cartridge, this refers to an Interchim pre-packed polypropylene column (or equivalent) containing unbounded activated silica with spherical particles with average size of 15 pm or Isolute® pre-packed polypropylene column (or equivalent) containing unbounded activated silica with irregular particles with average size of 50 pm. Fractions containing the required product (identified by TLC and / or LCMS analysis) were pooled and concentrated in vacuo. Where an SCX cartridge was used, ‘SCX cartridge’ refers to a Bond Elut® pre-packed polypropylene column (or equivalent) containing a non-end-capped propylsulphonic acid functionalised silica strong cation exchange sorbent.

[0268] NMR Methods

[0269] NMR spectra were obtained on a Bruker Avance III 600 (5 mm RT inverse probe head), Bruker DRX 500, Bruker Avance AV 400 (5 mm RT direct probehead) or Bruker DPX 300 spectrometers using standard Bruker pulse sequences. DMSO-de, MeOD-d4 or CDCh were used as solvents. All experiments were recorded at 298 K, unless stated differently. Chemical shifts are reported as 5 values in ppm relative to tetramethylsilane or solvent residual peak. Coupling constants (J values) are given in hertz (Hz) and multiplicities are reported using the following abbreviation: s=singlet, d=doublet, t=triplet, q=quartet, m=multiplet, br=broad, nd=not determined.

[0270] LC-MS Methods

[0271] Method 1

[0272] Method 1 was performed on Acquity UPLC® coupled with SQD mass spectrometer; Column: Acquity BEH C18 (50mm x 2.1mm i.d., 1.7pm), mobile phase A: 0.1% (v / v) formic acid in water, mobile phase B: 0.1% (v / v) formic acid in acetonitrile. See Table 2 for gradient details.

[0273] Table 2: LC-MS- method 1 conditions

[0274] Column temperature: 40 °C; UV detection: from 210 nm to 400 nm; MS conditions: Ionisation Mode: alternate- scan Positive and Negative Electrospray (ES+ZES-), Scan Range: 100 to 1500 AMU.

[0275] Method 2

[0276] Method 2 was performed on Acquity H class UPLC® coupled with QDA mass spectrometer; Column: Acquity BEH C18 (100mm x 2.1mm i.d., 1.7pm), mobile phase A: 0.1% (v / v) formic acid in water, mobile phase B: 0.1% (v / v) formic acid in acetonitrile. See Table 3 for gradient details. Table 3: LC-MS- method 2 conditions

[0277] Column temperature: 40 °C; UV detection: from 210 nm to 400 nm; MS conditions: Ionisation Mode: alternate- scan Positive and Negative Electrospray (ES+ZES-), Scan Range: 100 to 1250 AMU. Method 3a

[0278] Method 3a was performed on Acquity UPLC® coupled with SQD mass spectrometer; Column: Acquity BEH C18 (50mm x 2.1mm i.d., 1.7pm), mobile phase A: 10 mM aqueous solution of ammonium bicarbonate (adjusted to pH 10 with ammonia), mobile phase B: acetonitrile. See Table 4 for gradient details.

[0279] Table 4: LC-MS- method 3a conditions

[0280] Column temperature: 40 °C; UV detection: from 210 nm to 400 nm; MS conditions:

[0281] Ionisation Mode: alternate- scan Positive and Negative Electrospray (ES+ / ES-), Scan Range: 100 to 1500 AMU.

[0282] Method 4 Acquity UPLC coupled with SQD mass spectrometer; Column: Acquity BEH C18 (100mm x 2.1mm i.d., 1.7pm), mobile phase A: 0.1% (v / v) formic acid in water, mobile phase B: 0.1% (v / v) formic acid in acetonitrile; see Table 5. Table 5 - Method 4 conditions

[0283] Column temperature: 40 °C; UV detection: from 210 nm to 400 nm; MS conditions: Ionisation Mode: alternate- scan Positive and Negative Electrospray (ES+ / ES-), Scan Range: 100 to 1500 AMU. Method 5

[0284] Acquity UPLC coupled with SQD mass spectrometer; Column: Acquity BEH C18 (100mm x 2.1mm i.d., 1.7pm), mobile phase A: 10 mM aqueous solution of ammonium bicarbonate (adjusted to pH 10 with ammonia), mobile phase B: acetonitrile.; see Table 6.

[0285] Table 6 - Method 5 conditions Column temperature: 40 °C; UV detection: from 210 nm to 400 nm; MS conditions:

[0286] Ionisation Mode: alternate- scan Positive and Negative Electrospray (ES+ZES-), Scan Range: 100 to 1500 AMU.

[0287] Method 6

[0288] Method 6 as reported in Table 7 was performed on Acquity CSH Cl 8 column 50mm x 2.1mm 1.7pm, maintained at 40°C; Mobile Phase: Eluent B (ACN / water 95:5 +0.05% HCOOH) in Eluent A (water / ACN 95:5 +0.05% HCOOH) from 1% to 99.9% within 3.5 min. Table 7:LC-MS- method 6 conditions

[0289] Column temperature: 40 °C; UV detection: from 210 nm to 400 nm; UPLC + Waters PDA + Waters QDA.

[0290] Chiral separation protocols

[0291] The diastereomeric separation of compounds was achieved by Supercritical Fluid Chromatography (SFC), using any of the following instruments: Novasep SUPERSEP 400, Sepiatec preparative SFC system (PreplOO), Multigram 2 Preparative SFC system, ABsys2 Preparative SFC system, or by Liquid Chromatography (LC) using Gilson Preparative LC system. Appropriate isocratic methods were selected based on methanol or ethanol solvent systems under basic conditions. The fractions that contained the desired product were evaporated to near dryness using a rotary evaporator. The resultant solids were then transferred into final vessels with MeOH or EtOH, which was removed on a Biotage V10 at 35°C before being freeze dried. Analysis of two enantiomers was performed from reconstituted final samples on a Waters Acquity UPC2 system (SFC, SFC-MS) or an Agilent 1100 HPLC system (LC).

[0292] Preparative chiral separations

[0293] Method Chiral-Prep-1: SFC-MS was performed using a CHIRALPAK® IG (21mm x 250 mm, 5pm) column with an isocratic run (35:65 MeOELCCh (0.2% v / v NH3)), Flow Rate 50 mL / min, BPR 100 BarG, Detector Wavelength 223 nm, Injection Volume 0.7 mL (4.2 mg), 40°C column temperature.

[0294] Method Chiral-Prep-2: SFC-MS was performed using a CHIRALPAK® IG (21mm x 250 mm, 5pm) column with an isocratic run (40:60 MeOH:CCh (0.2% v / v NH3)), Flow Rate 50 mL / min, BPR 100 BarG, Detector Wavelength 222 nm, Injection Volume 0.5 mL (4.6 mg), 40 °C column temperature.

[0295] Method Chiral-Prep-3: SFC was performed using a CHIRALPAK® IH column (250 mm x 50mm, 5 pm) with an isocratic run (10:90 EtOH:CCh), Flow Rate 300 g / min, Outlet pressure 130 bar, UV detection @ 240 nm, 25°C column temperature.

[0296] Chiral analytical methods

[0297] Method Chiral-QC-1: SFC-MS was performed using a CHIRALPAK® IG (4.6mm x 250mm, 5pm) column with an isocratic run (40:60 MeOH:CO2 (0.1% v / v NH3)), Flow Rate 3 mL / min, BPR 125 BarG, Detector Wavelength 210-400 nm, Injection Volume 1.0 pL, 40 °C column temperature.

[0298] Method Chiral-QC-2: LC was performed using a CHIRALPAK® IH column (250mm x 4.6 mm, 5 pm) with an isocratic run (70:30 n-heptane / DCM), Flow Rate 1.0 mL / min, diode array detection @ 230 nm, 25°C column temperature. Sample was dissolved in mobile phase, then injected.

[0299] Method Chiral-QC-3 : SFC-MS was performed using, as chiral stationary phase, cellulose- based CHIRALPAK® IA3 column (Daicel, 4.6 mm x 150 mm, 3 pm) with an isocratic run (Mobile phase eluent: acetonitrile / 0, 1% FA in H2O (1 / 1), Flow Rate 1 mL / min, Detector Wavelength 298 nm, method length 15 min, Injection Volume 10 uL, 40 °C column temperature.

[0300] PREPARATION OF INTERMEDIATES:

[0301] Intermediate (III-23): methyl (E)-2-azido-3-(2-chloro-3,4-difluoro-phenyl)prop-2- enoate

[0302] To a solution of sodium methanolate (25 wt% in methanol, 1.94 mL, 8.50 mmol) in methanol (4.5 mL), 2-chloro-3,4-difluoro-benzaldehyde (500 mg, 2.83 mmol) was added in several portions at -20 °C under argon, followed by methyl 2-azidoacetate (0.83 mL, 8.50 mmol). The reaction mixture was left to warm to room temperature and was stirred at rt for 1.5 h.

[0303] The mixture was poured into water and a white solid was precipitated from the mixture. The desired product was filtered, washed with mother liquor and dried in suction to give desired product (426 mg, 1.5 mmol, 53 % yield).

[0304] LC-MS Method 1 : r.t. 1.38 min, no ionization.

[0305] Intermediate (IV-23): methyl 4-chloro-5,6-difluoro-lH-indole-2-carboxylate

[0306] Intermediate (III-23) Methyl (E)-2-azido-3-(2-chl oro-3, 4-difluoro-phenyl)prop-2-enoate (424 mg, 1.49 mmol) was added to xylene (100.0 mL) in one portion and the solution was left stirring at 120°C for 2h. The reaction mixture was cooled to rt and concentrated under vacuum. To the residue, n-heptane was added and left in a refrigerator at 8 C° overnight and filtered. The solid was washed with n-heptane and dried to give desired product (93.5 mg, 0.37 mmol, 25 % yield).

[0307] LC-MS Method 1 : r.t. 1.19 min, MS ESI (+) m / z = 244.29 [M+H]+.

[0308] Intermediates (V)

[0309] Intermediate (V-10): Synthesis of methyl 4-chloro-5-fluoro-l-methyl-indole-2- carboxylate

[0310] To a solution of commercially available methyl 4-chloro-5-fluoro-lH-indole-2-carboxylate (325 mg, 1.43 mmol) in dry DMF (10.5 mL), potassium carbonate (592 mg, 4.28 mmol) was added, followed by Mel (267 pL, 4.28 mmol). The resulting mixture was heated to 50 °C overnight. The reaction mixture was cooled down to rt and quenched with water and extracted with EtOAc. The combined organic phase was washed with water and brine, dried over Na2SO4, filtered and evaporated under vacuum.

[0311] The crude was purified by FCC (Cyclohexane : EtOAc =9: 1). Appropriate fractions were combined and evaporated under reduced pressure to afford desired product (287.3 mg, 1.19 mmol, 83 % yield).

[0312] LC-MS Method 1 : r.t. 1.29 min, MS ESI (+) m / z = 241.88 [M+H]+.

[0313] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Intermediates V in Table 8 below, starting from proper Intermediates IV:

[0314] Table 8 - Intermediates (V)

[0315] Intermediates (VI)

[0316] Intermediates (VI-10): 4-chloro-5-fluoro-l-methyl-indole-2-carboxylic acid

[0317] To a solution of Intermediate (V-10) methyl 4-chloro-5-fluoro-l-methyl-indole-2- carboxylate (283 mg, 1.17 mmol) in a mixture solvent of THF (7.0 mL) and H2O (7.0 mL) LiOH (84.1 mg, 3.5 mmol) was added. The reaction mixture was stirred at room temperature for 2h.

[0318] The reaction mixture was poured into cool water and acidified with IM hydrochloric acid solution until pH = 2. The desired product was precipitated and filtered on vacuum to yield desired product (181.3 mg, 0.78 mmol, 68 % yield).

[0319] LC-MS Method 1 : r.t. 1.05 min, MS ESI (+) m / z = 227.97 [M+H]+.

[0320] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Intermediates VI in table 9 below, starting from proper Intermediates V: Table 9 - Intermediates (VI)

[0321] Intermediates (VII)

[0322] Intermediate (VII): 3-(4-bromophenyl)tetrahydrofuran-3-carbonitrile

[0323] To a suspension of sodium hydride (60 % dispersion in mineral oil, 2.55 g, 63.7 mmol) in DMF (35 mL) a solution of 2-(4-bromophenyl)acetonitrile (5 g, 25.5 mmol) and l-chloro-2- (chloromethoxy)ethane (2.83 mL, 28.1 mmol) in DMF (8.75 mL) was added dropwise at -10 °C under Argon atmosphere. The mixture was stirred at that temperature for 1 h, then left to stir at RT overnight. On completion, the reaction mixture was cooled to 0 °C and water (100 mL) was added slowly. The mixture was extracted with TBME (3x50 mL). The organic layers were combined, washed with brine, dried and evaporated. The oily residue was purified by flash chromatography on a Si cartridge (gradient elution 0-20 % EtOAc in cyclohexane) to give the title compound as an oil (3.74 g, 14.8 mmol, 58 % yield).

[0324] 'H NMR (500 MHz, DMSO-de): 5 7.66 (d, J = 8.5 Hz, 2H), 7.48 (d, J = 8.5 Hz, 2H), 4.38 (d, J = 8.9 Hz, 1H), 4.08-4.03 (m, 2H), 3.84 (d, J = 8.9 Hz, 1H), 2.81-2.73 (m, 1H), 2.49-2.43 (m, 1H).

[0325] Intermediates (VH-a) and (VH-b): 1steluted enantiomer and 2ndeluted enantiomer of 3-(4-bromophenyl)tetrahydrofuran-3-carbonitrile.

[0326] (Vll-a) and (Vll-b)

[0327] A racemic mixture of 3 -(4-bromophenyl)tetrahydrofuran-3 -carbonitrile (160 g, 63.5 mmol), was dissolved in 100% EtOH at 100 g / L concentration and was separated by Method-Chiral -Prep- 3, to give the desired products.

[0328] 1steluted enantiomer (Intermediate VILa): 77.9 g, yield 49%.

[0329] 2ndeluted enantiomer (Intermediate Vll-b): 78.2 g, yield 49%.

[0330] Table 10: analytical data of intermediate (VH-a) and (VH-b)

[0331] Intermediates (VIII)

[0332] Intermediate (VUI-a): ethyl 2-(4-(3-cyanotetrahydrofuran-3-yl)phenyl)acetate

[0333] (Vlll-a) Step 1: Synthesis of Reformatsky reagent / bromo-(2-ethoxy-2 -oxo-ethyl) zinc:

[0334] A mixture of the zinc granular, 30-100 mesh (40.0 g, 612.0 mmol) in anhydrous 2-MeTHF (250 mL), under N2, was warmed to 30 °C. At that temperature 10 % of the total of ethyl 2- bromoacetate (2.5 g, 1.65 mL, 15.0 mmol), followed by DIBAL-H, IM in toluene (5.99 mL, 6.0 mmol) were added to the reaction mixture. The suspension was heated to 40 °C and then ethyl 2- bromoacetate (47.5 g, 31.5 mL, 284.4 mmol) was added dropwise over 1.5 h, maintaining the temperature between 45 °C and 50 °C. During that period color of the reaction mixture became orange. After the addition of 2-bromoacetate was completed, the reaction mixture was stirred for 40 minutes, during which time the temperature of the reaction mixture gradually decreased to RT. The resulting mixture was used in the next reaction step as is, calculating concentration as 1.05 mol / L.

[0335] Step 2: Negishi cross-coupling

[0336] A solution of 3 -(4-bromophenyl)tetrahydrofuran-3 -carbonitrile (Intermediate VILa) (15.0 g, 59.5 mmol) in dry 2-MeTHF (100 mL) was purged with N2 for 20 min. The purging of the reaction mixture with N2 was continued and then XPhos (5.67 g, 11.9 mmol), followed by Pd2(dba)s (5.45 g, 5.9 mmol) were added. The reaction mixture was heated to 45°C and then a freshly prepared solution of bromo-(2-ethoxy-2-oxo-ethyl)zinc, 1.05 M in 2-MeTHF (1.05 mol / L, 113.3 mL, 119.0 mmol) was added dropwise at 45°C over 2 h. The reaction mixture was stirred at 45°C for additional 30 min, then cooled to RT. To the reaction mixture saturated aqueous NH4Q (100 ml) was added, stirred for 30 min and filtered over a pad of Celite. The residue was washed with EtOAc. The layers were separated and the organic layer was washed with brine and concentrated in vacuo to give crude product (30.24 g) as dark oily residue. The crude product was purified by flash chromatography on a Si cartridge (gradient elution 0-13 % EtOAc in cyclohesane) affording brown oil (13.47 g) which was re-purified by second flash chromatography on a Si cartridge (gradient elution 0-10 % EtOAc in DCM) to yield the title compound as yellow oil (12.4 g, 47.3 mmol, 79 % yield).

[0337] LC-MS Method 1 : r.t. 1.00 min, MS ESI (+) m / z = 260.02 [M+H]+.

[0338] 'H NMR (500 MHz, DMSO-de): 5 7.47 (d, J = 8.2 Hz, 2H), 7.34 (d, J = 8.2 Hz, 2H), 4.39 (d, J = 8.9 Hz, 1H), 4.11-4.03 (m, 4H), 3.83 (d, J = 8.9 Hz, 1H), 3.69 (s, 2H), 2.79-2.72 (m, 1H), 2.53 - 2.46 (m, 1H), 1.19 (t, J = 7.1 Hz, 3H).

[0339] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Intermediates (VIII) in table 11 below, starting from proper Intermediates (VII): Table 11-Intermediates (VIII)

[0340] Intermediates (IX)

[0341] Intermediate (IX-3): ethyl 2-(4-(3-cyanotetrahydrofuran-3-yl)phenyl)-4- methoxybutanoate

[0342] A solution of ethyl 2-[4-[3-cyanotetrahydrofuran-3-yl]phenyl]acetate (Intermediate (Vlll-a) (3.34 g, 12.9 mmol) in anhydrous DMF (15 mL) was bubbled with argon and cooled to -10 °C. LiHMDS, 1.3 M in THF (11.0 mL, 14.3 mmol) was added dropwise at -10°C under the argon atmosphere and the reaction mixture was stirred at -10-0°C for 1 h. Then, l-bromo-2-methoxy- ethane (1.97 g, 1.33 mL, 14.2 mmol) dissolved in anhydrous DMF (5 mL) was added dropwise into the solution maintaining the temperature between -10 °C and 0 °C and stirring was continued at that temperature for 1 h. The reaction mixture was poured into cold saturated aqueous ammonium chloride solution (150 ml) and extracted with EtOAc (3x). The organic layers were combined, washed with brine, dried and evaporated. The obtained crude product was purified by flash chromatography on a Si cartridge (gradient elution 0-20 % EtOAc in cyclohexane) to yield the title compound (2.52 g, 7.9 mmol, 62 % yield).

[0343] LC-MS Method 1 : r.t. 1.06 min, MS ESI (+) m / z = 318.13 [M+H]+.

[0344] 'H NMR (500 MHz, DMSO-d6): 5 7.48 (d, J = 8.2 Hz, 2H), 7.36 (d, J = 8.2 Hz, 2H), 4.38 (d, J = 8.9 Hz, 1H), 4.13-3.98 (m, 4H), 3.84 (d, J = 8.9 Hz, 1H), 3.74 (t, J = 7.6 Hz, 1H), 3.29-3.20 (m, 2H), 3.19 (s, 3H), 2.78-2.72 (m, 1H), 2.53 - 2.46 (m, 1H), 2.28-2.19 (m, 1H), 1.90-1.82 (m, 1H), 1.13 (t, J = 7.1 Hz, 3H).

[0345] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Intermediates (IX) in Table 12 below, starting from proper Intermediates (VIII):

[0346] Table 12- Intermediates (IX)

[0347] Intermediates (X)

[0348] Intermediate (X-3): ethyl 2-(4-(3-carbamoyltetrahydrofuran-3-yl)phenyl)-4- methoxybutanoate

[0349] (X-3)

[0350] To a solution of ethyl 2-[4-[3-cyanotetrahydrofuran-3-yl]phenyl]-4-methoxy-butanoate (Intermediate IX-3) (2.52 g, 7.9 mmol) in DMSO (25 mL), potassium carbonate (5.49 g, 39.7 mmol) was added, followed by dropwise addition of hydrogen peroxide (30.0 %, 8.11 mL, 79.4 mmol). The reaction mixture was left to stir at RT overnight. The reaction was completed. The mixture was cooled with an ice bath, then EtOAc and water were added. Product was extracted with EtOAc (3x). The organic layers were combined, washed with brine, dried over sodium sulfate, filtered and evaporated in vacuo to yield title compound (1.98 g, 5.9 mmol, yield 74 %).

[0351] LC-MS Method 1 : r.t. 0.82 min, MS ESI (+) m / z = 336.13 [M+H]+.

[0352] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of intermediates (X) in Table 13 below, starting from proper intermediates (IX):

[0353] Table 13- Intermediates (X)

[0354] Intermediates (XI)

[0355] Intermediate (XI-3): ethyl 2-(4-(3-aminotetrahydrofuran-3-yl)phenyl)-4- methoxybutanoate

[0356] Ethyl 2-[4-[3-carbamoyltetrahydrofuran-3-yl]phenyl]-4-methoxy-butanoate (Intermediate X-3) (1.98 g, 5.9 mmol) was dissolved in a solvent mixture of acetonitrile (26 mL) and water (20 mL). [Bis(trifluoroacetoxy)iodo]benzene (3.05 g, 7.1 mmol) was added and the reaction mixture was stirred at 50 °C for 2 h. The mixture was concentrated under reduced pressure and diluted with water. Saturated aqueous NaHCCh was added to the stirred mixture to adjust pH > 8. The reaction mixture was extracted with EtOAc (3x). The combined organic phases were washed with brine, dried over anhydrous sodium sulfate and evaporated to dryness. The obtained crude product was dissolved in MeOH, inserted to SCX column (20 g) and eluted with MeOH, followed by 2M ammonia in MeOH. Ammonia / MeOH fractions were combined and evaporated in vacuo to dryness affording the title compound (1.31 g, 4.26 mmol, yield 72 %). LC-MS Method 1 : r.t. 0.58 min, MS ESI (+) m / z = 291.11 [M-NH2]+.

[0357] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Intermediates (XI) in Table 14 below, starting from proper Intermediates (X):

[0358] Table 14- Intermediates (XI)

[0359] Examples

[0360] Example (1-3): ethyl 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoate

[0361] To a solution of 4-chloro-5-methoxy-l-methyl-indole-2-carboxylic acid (1.12 g, 4.7 mmol) in dry DMF (30 mL), HATU (1.78 g, 4.7 mmol) and DIPEA (1.64 mL, 9.4 mmol) were added. After stirring for 30 min, ethyl 2-[4-[3-[(4-chloro-5-methoxy-l-methyl-indole-2- carbonyl)amino]tetrahydrofuran-3-yl]phenyl]-4-methoxy-butanoate (Intermediate XI-3) (1.31 g, 4.3 mmol) was dissolved in dry DMF (5 mL) and added to the reaction mixture. The reaction mixture was stirred at RT for 1 h. The reaction was quenched with water and the resulting mixture extracted with EtOAc (3x). The organic layers were combined, washed with saturated aqueous NaHCCh (2x), then with brine, dried over anhydrous sodium sulfate, filtered and evaporated. The obtained brownish crude material was purified by flash chromatography on a Si cartridge (gradient elution 0-40 % EtOAc in cyclohexane) to afford title compound (1.91 g, 3.6 mmol, 85 % yield).

[0362] LC-MS Method 2: r.t. 7.44 min, MS ESI (+) m / z = 529.42 [M+H]+.

[0363] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Examples in table 15 below, starting from proper intermediates (VI) and (XI):

[0364] Table 15- Examples

[0365] Example 3: Diastereoisomers 1 and 2 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH- indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid Ethyl 2-[4-[3-[(4-chloro-5-methoxy-l-methyl-indole-2-carbonyl)amino]tetrahydrofuran-3- yl]phenyl]-4-methoxy-butanoate (1-3) (1.8 g, 0.2 mmol) was dissolved in a mixture of methanol (45 mL) and THF (25 mL), then potassium hydroxide (5M aqueous solution, 6.8 mL, 34.0 mmol) and H2O (25 mL) were added. The reaction mixture was stirred at 60 °C for 1.5 h, then concentrated in vacuo. The obtained residue was diluted with water and acidified with IM HC1 aqueous solution to pH 2. Formed precipitate was collected by filtration and dried in vacuum oven to yield the title compound as off-white solid (1.56 g, 3.1 mmol, 90 % yield).

[0366] LC-MS Method 2: r.t. 6.25 min, MS ESI (+) m / z = 501.41 [M+H]+.

[0367] 1H NMR (500 MHz, DMSO-de): 5 12.34 (s, 1H), 9.06 (s, 1H), 7.49 (d, J = 9.1 Hz, 1H), 7.39 (d, J = 8.2 Hz, 2H), 7.30 (s, 1H), 7.26 - 7.20 (m, 3H), 4.25 (d, J = 9.1 Hz, 1H), 4.13 - 4.08 (m,

[0368] 1H), 3.96 - 3.91 (m, 2H), 3.89 - 3.85 (m, 6H), 3.58 (t, J = 7.3 Hz, 1H), 3.28 - 3.19 (m, 2H), 3.18 (s, 3H), 2.80 - 2.73 (m, 1H), 2.34 - 2.26 (m, 1H), 2.23 - 2.14 (m, 1H), 1.85 - 1.76 (m, 1H).

[0369] The same synthetic procedure, or adaptations thereof, was applied to the synthesis of Examples in table 16 below, starting from proper Example of formula (I): Table 16- Examples

[0370] Examples from chiral separations

[0371] Examples 4 and 5: diastereoisomer 1 and diastereoisomer 2 of 2-(4-(3-(4-chloro-5- methoxy-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)-4- methoxybutanoic acid (Example 3)

[0372] A mixture of two diastereoisomers (Example 3, 500 mg, 1.0 mmol), was dissolved to 6 mg / mL in EtOH and was separated using Method Chiral -Prep- 1 to give the desired products, Example 4 and 5, as white solids.

[0373] 1steluted: diastereoisomer l(Example 4): 154.0 mg, 31 % yield.

[0374] 2ndeluted: diastereoisomer 2 (Example 5): 146.5 mg, 29 % yield.

[0375] Analytical data are reported in Table 17 below.

[0376] Examples 7 and 8: diastereoisomer 3 and diastereoisomer 4 of 2-(4-(3-(4-chloro-5- methoxy-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)-4- methoxybutanoic acid (Example 6)

[0377] A mixture of two diastereoisomers (Example 6, 500 mg, 1.0 mmol), was dissolved to 9.1 mg / mL in MeOH and was separated using Method Chiral-Prep-2 to give the desired products, Example 7 and 8, as white solids.

[0378] 1steluted: diastereoisomer 3 (Example 7): 187.2 mg, 37 % yield.

[0379] 2ndeluted: diastereoisomer 4 (Example 8): 181.1 mg, 36 % yield.

[0380] Analytical data are reported in Table 17 below. Table 17-Analytical data for Examples 4, 5, 7, 8

[0381] Example 25: Diastereoisomers 1 and 2 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid Step 1: ethyl 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-4-methoxybutanoate

[0382] The compound was prepared by following the procedure described for Intermediate (1-12) starting from (VI-12) and (XI-3) (272 mg, 0.53 mmol, 79 % yield).

[0383] (Method 1) r.t. = 1.37 min, ES+m / z 513.23 [M+H]+

[0384] Step 2: 2-(4-(3-(4-chloro-l , 6-dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-4-methoxybutanoic acid

[0385] Following the procedure described for Example 3, starting from ethyl 2-(4-(3-(4-chloro-l,6- dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoate the title compound was obtained (250 mg, 0.51 mmol, 98 % yield).

[0386] (Method 1) r.t. = 1.18 min, ES+m / z 485.20 [M+H]+

[0387] Intermediates (XII-13) and (XII-14): Diastereomeric mixture of N-(3-(4-(l-((S)-4- benzyl-2-oxooxazolidin-3-yl)-4-methoxy-l-oxobutan-2-yl)phenyl)tetrahydrofuran-3-yl)-4- chloro-l,6-dimethyl-lH-indole-2-carboxamide

[0388] To a stirred solution of Diastereoisomers 1 and 2 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH- indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)-4-m ethoxybutanoic acid (Example 25) as diastereomeric mixture (250 mg, 0.52 mmol) in dry THF (5 mL) and diethyl ether (2 mL) under argon at - 78°C, triethylamine (0.086 mL, 0.62 mmol) was added, followed by addition of the Pivaloyl chloride (0.076 mL, 0.62 mmol). The resulting suspension was stirred at 0°C for 30 min and at rt for 30 min.

[0389] Meanwhile a solution of the (4S)-4-benzyloxazolidin-2-one (274 mg, 1.5 mmol) in dry THF (8 mL) was cooled at -78°C and n-BuLi 2.5 M solution in hexane (2.5 mol / L, 0.74 mL, 1.9 mmol) was added. The resulting solution was stirred at -78°C for 15 min and then added into solution of the mixed anhydride. The mixture was stirred at -78°C for 15 min at 0°C for 60 min.

[0390] Sat. NH4Q (1 ml) was added to quench the reaction. THF was removed in vacuo and the residue was extracted with EtOAC. The combined organic extracts were washed with brine, dried over Na2SO4 and evaporated under vacuum. The crude product was purified by FCC (from 0 to 35% EtOAc in cyclohexane). The title compounds were obtained:

[0391] 78 mg of the XII- 14. (First eluting isomer)

[0392] (Method 1) r.t. = 1.41 min, ES+m / z 644.31 [M+H]+and

[0393] 129 mg of XII-13. (Second eluting isomer)

[0394] (Method 1) r.t. = 1.45 min, ES+m / z 644.32 [M+H]+

[0395] Example 13: diastereoisomer 2 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid, second eluting

[0396] In a solution of the Intermediate (XII-13) N-[(3R)-3-[4-[l-[(4S)-4-benzyl-2-oxo- oxazolidine-3-carbonyl]-3-methoxy-propyl]phenyl]tetrahy drofuran-3-yl]-4-chl oro-1, 6-dimethyl- indole-2-carboxamide (77 mg, 0.12 mmol) in the THF (0.45 mL) and water (0.14 mL) at 0°C, hydrogen peroxide (30 %, 0.059 mL, 0.58 mmol) was added followed by addition of the lithium hydroxide (5.6 mg, 0.23 mmol) in water (56 pL). Reaction mixture was stirred at 0°C for 15 min and at rt for 3 h. Reaction mixture was cooled to 0°C and aq. solution of the NaHSCh was added. Stirring was continued for 60 min at rt. Solvent was removed and residue diluted with water, pH was adjusted to pH=2. Precipitate formed was filtered off, triturated from MeOH and dried to give title compound (30 mg, 0.06 mmol, 52 % yield).

[0397] (Method 2) r.t. = 7.07 min, ES+m / z 485.40 [M+H]+

[0398] (Method Chiral-QC-3) r.t. = 8.073 min, de = 97.5 %

[0399] 'HNMR (500 MHz, DMSO-t / 6): 5 12.38 (bs, 1 H), 9.03 (s, 1 H), 7.38 (d, J = 8.2 Hz, 2 H), 7.35 (s, 1 H), 7.32 (s, 1 H), 7.23 (d, J= 8.2 Hz, 2 H), 7.05 (s, 1 H), 4.25 (d, J= 9.2 Hz, 1 H), 4.10 (d, J= 9.2 Hz,l H), 3.96 - 3.91 (m, 2 H), 3.87 (s, 3 H), 3.57 (t, J= 7.7 Hz, 1 H), 3.27 - 3.21 (m, 2 H), 3.18 (s, 3 H), 2.81 - 2.74 (m, 1 H), 2.43 (s, 3 H), 2.34 - 2.26 (m, 1 H), 2.23 - 2.15 (m, 1 H), 1.85 - 1.78 (m, 1 H). Example 14: diastereoisomer 1 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid, First eluting

[0400] Example 14 was prepared by following the preparation of Example 13 starting from XII-14 to give title compound (40 mg, 0.08 mmol, 41 % yield).

[0401] (Method Chiral-QC-3) r.t. = 5.777 min, de = 100 %

[0402] 'HNMR (500 MHz, DMSO-d6): 5 12.42 (bs, 1 H), 9.03 (s, 1 H), 7.38 (d, J= 8.2 Hz, 2 H), 7.35 (s, 1 H), 7.32 (s, 1 H), 7.23 (d, J= 8.2 Hz, 2 H), 7.05 (s, 1 H), 4.25 (d, J= 9.2 Hz, 1 H), 4.10 (d, J= 9.2 Hz,l H), 3.96 - 3.91 (m, 2 H), 3.87 (s, 3 H), 3.57 (t, J= 7.7 Hz, 1 H), 3.27 - 3.21 (m, 2 H), 3.18 (s, 3 H), 2.81 - 2.74 (m, 1 H), 2.43 (s, 3 H), 2.34 - 2.26 (m, 1 H), 2.23 - 2.15 (m, 1 H), 1.85 - 1.78 (m, 1 H).

[0403] COMPARATIVE EXAMPLES

[0404] Newly synthesized comparative examples A, B and C were prepared as described below.

[0405] Comparative Example A is characterized by a small linear chain with two carbon atoms and a final morpholino group in position alpha to the carboxyl group, instead of a small linear chain with two carbon atoms and a final ORi group in position alpha to the COORe group, as the compounds of formula (I) of the invention.

[0406] Comparative Example B is characterized by a small linear chain with three carbon atoms and a final ORi group in position alpha to carboxylic acid, instead of a small linear chain with two carbon atoms and final ORi group in position alpha to the COORe group, as the compounds of formula (I) of the invention.

[0407] Comparative Example C is characterized by a small branched chain with three carbon atoms and by the absence of a final ORi group in position alpha to carboxylic acid, instead of a small linear chain with two carbon atoms and a final ORi group in position alpha to the COORe group, as the compounds of formula (I) of the invention.

[0408] Comparative Example A: 2-(4-(3-(4,5-dichloro-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-morpholinobutanoic acid

[0409]

[0410] Intermediate (IX-Comp-A): ethyl 2-(4-(3-cyanotetrahydrofuran-3-yl)phenyl)-4- morpholinobutanoate

[0411] Following the procedure of (IX-3), starting from Intermediate (VIII), the title compound was obtained (42 mg, 0.11 mmol, 29 % yield).

[0412] (Method 3a) r.t. = 0.98 min, ES+m / z 373.2 [M+H]+

[0413] Intermediate (X-Comp-A): ethyl 2-(4-(3-carbamoyltetrahydrofuran-3-yl)phenyl)-4- morpholinobutanoate

[0414] Following the procedure of (X-3), starting from Intermediate (IX-Comp-A), the title compound was obtained (34 mg, 0.09 mmol, 37 % yield).

[0415] (Method 3a) r.t. = 0.75 min, ES+m / z 390.98 [M+H]+

[0416] Intermediate (XI-Comp-A): ethyl 2-(4-(3-aminotetrahydrofuran-3-yl)phenyl)-4- morpholinobutanoate

[0417] Following the procedure of (XI-3), starting from Intermediate (X-Comp-A), the title compound was obtained (27 mg, 0.04 mmol, 49 % yield).

[0418] (Method 3a) r.t. = 0.76 min, ES+m / z 363.2 [M+H]+

[0419] Step 1: ethyl 2-[4-[3-[(4,5-dichloro-l-methyl-indole-2-carbonyl)amino]tetrahydrofuran-3- yl phenyl ]-4-morpholino-butanoate ( / -Comp-4 )

[0420] Following the procedure of Example 1-3, starting from commercially available 4,5-Dichloro- 1 -methyl- l / Z-indole-2-carboxylic acid and (XI-Comp-A), the title compound was obtained (11 mg, 0.018 mmol, 24 % yield).

[0421] (Method 3a) r.t. = 1.18 min, ES+m / z 589.95 [M+H]+

[0422] Step 2: 2-(4-(3-(4,5-dichloro-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-4-morpholinobutanoic acid

[0423] Following the procedure of Example 3, starting from (I-Comp-A), the title compound was obtained (9 mg, 0.016 mmol, 84 % yield).

[0424] (Method 5) r.t. = 2.57 min, ES+m / z 559.93 [M+H]+

[0425] 'H NMR (500 MHz, DMSO-d6): 5 9.14 (s, 1H), 7.59 (d, J = 8.9 Hz, 1H), 7.44 (d, J = 8.9 Hz, 1H), 7.41 (s, 1H), 7.36 (d, J = 8.1 Hz, 2H), 7.24 (d, J = 8.1 Hz, 2H), 4.25 (d, J = 9.1 Hz, 1H), 4.09 (d, J = 9.1 Hz, 1H), 3.97 - 3.90 (m, 2H), 3.90 (s, 3H), 3.55 - 3.50 (m, 5H), 2.81 - 2.71 (m, 1H), 2.34 - 2.24 (m, 5H), 2.23 - 2.06 (m, 3H), 1.76 - 1.66 (m, 1H).

[0426] Comparative Example B: 2-(4-(3-(4,5-dichloro-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-5-methoxypentanoic acid

[0427] Intermediate (IX-Comp-B): ethyl 2-(4-(3-cyanotetrahydrofuran-3-yl)phenyl)-5- methoxypentanoate Following the procedure of (IX-3), starting from Intermediate (VIII), the title compound was obtained (108 mg, 0.32 mmol, 41 % yield).

[0428] (Method 3a) r.t. = 1.07 min, ES+m / z 332.13 [M+H]+

[0429] Intermediate (X-Comp-B): ethyl 2-(4-(3-carbamoyltetrahydrofuran-3-yl)phenyl)-5- methoxypentanoate

[0430] Following the procedure of (X-3), starting from Intermediate (IX-Comp-B), the title compound was obtained (95 mg, 0.27 mmol, 66 % yield).

[0431] (Method 3a) r.t. = 0.86 min, ES+m / z 350.17 [M+H]+

[0432] Intermediate (XI-Comp-B): ethyl 2-(4-(3-aminotetrahydrofuran-3-yl)phenyl)-5- methoxypentanoate

[0433] Following the procedure of (XI-3), starting from Intermediate (X-Comp-B), the title compound was obtained (66 mg, 0.19 mmol, 69 % yield).

[0434] (Method 3a) r.t. = 0.87 min, ES+m / z 322.03 [M+H]+5te / > 1: ethyl 2-(4-(3-(4,5-dichloro-l- methyl-lH-indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)-5-methoxypentanoate (I-Comp- B)

[0435] Following the procedure of Example 1-3, starting from commercially available 4,5-Dichloro- 1 -methyl- lZZ-indole-2-carboxylic acid and XI-Comp-B, the title compound was obtained (49 mg, 0.074 mmol, 36 % yield).

[0436] (Method 3a) r.t. = 1.30 min, ES+m / z 547.08 [M+H]+

[0437] Step 2: 2-(4-(3-(4,5-dichloro-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-5-methoxypentanoic acid

[0438] Following the procedure of Example 3, starting from (I-Comp-B), the title compound was obtained (21 mg, 0.041 mmol, 46 % yield).

[0439] (Method 5) r.t. = 2.55 min, ES+m / z 519.08 [M+H]+

[0440] 'H NMR (500 MHz, DMSO-t / e) b 12.31 (s, 1H), 9.14 (s, 1H), 7.59 (d, J= 8.8 Hz, 1H), 7.44 (d, J = 8.8 Hz, 1H), 7.42 (s, 1H), 7.38 (d, J= 7.3 Hz, 2H), 7.24 (d, J= 8.3 Hz, 2H), 4.25 (d, J= 9.1 Hz, 1H), 4.10 (d, J = 9.1 Hz, 1H), 3.96 - 3.91 (m, 2H), 3.90 (s, 3H), 3.47 (t, J= 7.7 Hz, 1H), 3.27 (t, .7= 6.4 Hz, 2H), 3.17 (s, 3H), 2.81 - 2.73 (m, 1H), 2.34 - 2.27 (m, 1H), 1.99 - 1.90 (m, 1H), 1.68 - 1.60 (m, 1H), 1.49 - 1.31 (m, 2H).

[0441] Comparative Example C: 2-(4-(3-(4-chloro-5-fluoro-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-3-methylbutanoic acid

[0442] Intermediate (IX-Comp-C): ethyl 2-(4-(3-cyanotetrahydrofuran-3-yl)phenyl)-3- methylbutanoate

[0443] Following the procedure of (IX-3), starting from Intermediate (VIII), the title compound was obtained (16.3 g, 54 mmol, 94 % yield).

[0444] (Method 6) r.t. = 2.13 min, ES+m / z 303.1 [M+H]+

[0445] Intermediate (X-Comp-C): ethyl 2-(4-(3-carbamoyltetrahydrofuran-3-yl)phenyl)-3- methylbutanoate

[0446] Following the procedure of (X-3), starting from Intermediate (IX-Comp-C), the title compound was obtained (12 g, 40 mmol, 84 % yield).

[0447] (Method 6) r.t. = 1.61 min, ES+m / z 320.3 [M+H]+

[0448] Intermediate (Xl-Comp-C): ethyl 2-(4-(3-aminotetrahydrofuran-3-yl)phenyl)-3- methylbutanoate

[0449] Following the procedure of (XI-3), starting from Intermediate (X-Comp-C), the title compound was obtained (1.8 g, 5.56 mmol, 81 % yield).

[0450] (Method 1) r.t. = 0.71 min, ES+m / z 275.10 [M-NH2]+

[0451] Step 1: ethyl 2 -(4-(3-(4-chloro-5-jluoro-l -methyl- lH-indole-2-

[0452] Following the procedure of Example 1-3, starting from (VI-10) and (Xl-Comp-C), the title compound was obtained (64 mg, 0.125 mmol, 95 % yield).

[0453] (Method 1) r.t. = 1.44 min, ES+m / z 501.18 [M+H]+

[0454] Step 2: 2-(4-(3-(4-chloro-5-fluoro-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-3-methylbutanoic acid

[0455] Following the procedure of Example 3, starting from (I-Comp-C), the title compound was obtained (27 mg, 0.057 mmol, 47 % yield).

[0456] (Method 2) r.t. = 6.88 min, ES+m / z 473.16 [M+H]+

[0457] ‘H NMR (600 MHz, DMSO-d6): 5 12.27 (bs, 1H), 9.11 (s, 1H), 7.59 - 7.56 (m, 1H), 7.42 (s, 1H), 7.38 (d, J = 8.2 Hz, 2H), 7.32 (t, J = 9.4 Hz, 1H), 7.26 (d, J = 8.2 Hz, 2H), 4.28 - 4.24 (m, 1H), 4.12 - 4.08 (m, 1H), 3.96- 3.92 (m, 2H), 3.90 (s, 3H), 3.07 (d, J = 10.3 Hz, 1H), 2.80 - 2.74 (m, 1H), 2.34 - 2.28 (m, 1H), 2.22 - 2.15 (m, 1H), 0.98 (d, J = 6.4 Hz, 3H), 0.62 (d, J = 6.4 Hz, 3H). PHARMACOLOGICAL ACTIVITY OF THE COMPOUNDS OF THE INVENTION

[0458] Phenotypic assay - High Content Screening optimization of a-SMA staining in NHLF cells

[0459] Method

[0460] NHLF cells (Lonza #CC2512) were seeded as 2 000 cells / well in 384-well plates in MEM medium w / o serine and glycine (Sigma #M2279) + 1% pen / strep + 5 mM L-glutamine + 10% FBS and incubated overnight at 37°C, 5% CO2.

[0461] The next day, cells were washed with PBS and starvation MEM medium w / o serine and glycine (0% FBS) was added and cells were incubated overnight at 37°C, 5% CO2. The day after, cells were pre-incubated with compounds or vehicle (0.3% DMSO) for 1 h. Compounds were tested at 9 consecutive 3 -fold dilutions starting from 30 pM. Each compound was tested in duplicate. Cells were further incubated for 72 h at 37°C, 5% CO2, 95% humidity. After 72h of incubation, a-SMA expression was quantified using immunostaining:

[0462] - Fixation in 4% paraformaldehyde,

[0463] - Blocking with 3% BSA, 2% FBS, 0.2% Triton-X in PBS,

[0464] - Primary ab. anti-a-SMA (AbCam #ab7817) diluted 500x in blocking buffer

[0465] - Anti-mouse secondary ab. AF488 (ThermoFisher #A11029) ....

[0466] % of a-SMA positive cells was determined by High Content Imaging (Molecular Device), data analysis was performed using MetaXpress software (Molecular Devices) and % of a-SMA positive was further used to calculate % of inhibition for tested compounds. Total cell number was determined by Hoechst staining and % of viability over TGFp stimulated controls was calculated.

[0467] Fibroblast to myofibroblast transition (FMT) in vitro assay: Collagen I detection

[0468] Method

[0469] NHLF cells were seeded as 80 000 cells / well in 12-well plates in MEM medium w / o serine and glycine (Sigma #M2279) + 1% pen / strep + 5 mM L-glutamine + 10% FBS and incubated overnight at 37°C, 5% CO2. To examine the expression of Collagen I, cells were treated with different concentrations of compounds, in MEM medium for Ih followed by stimulation with TGFp for 72 h at 37°C, 5% CO2. Following cell treatments, medium was removed and whole cell extracts were prepared by directly adding to the well the IX loading buffer (125 mM Tris-HCl pH 6.8, 4% SDS, 0.2% Orange G, 50% glycerol, 2.5% P-mercaptoethanol, Li-cor Biosciences), boiled for 5 min and then electrophoresed on Mini protean TGX gel 4-12% (Biorad). After electrophoresis, proteins were transferred to a nitrocellulose membrane. Immunodetection of Col- I, and glyceraldeide 3 -phosphate dehydrogenase (GAPDH) were obtained by using mouse antiColl Al (Santa Cruz) and rabbit anti -GAPDH (Cell Signaling Technology) all diluted at 1 : 1000 in TBS-tween 0.1%. Secondary antibodies were goat anti rabbit and goat anti mouse IgG conjugated with IRDye800 and IRDye680 probes (Li-cor) respectively, both diluted at 1 : 15,000 in TBS-tween 0.1% containing 1% of skim milk. Detection and quantification were performed with Odyssey imaging system (Li-cor) using GAPDH as loading control.

[0470] Results were expressed as ICso value, given in nM for each NCE or pICso (negative logarithm of ICso).

[0471] The results for individual compounds are provided below in Table 18.

[0472] Table 18 - pIC50 values in in vitro assays

[0473] As reported in the Table 18, all tested compounds, dose-dependently, reduce the expression of a-SMA, after 72 hours of incubation. It has been found that the compounds of formula (I) of the present invention have antifibrotic activity, monitored measuring the expression of a-SMA in Phenotypic assay, expressed as pICso, equal or higher than 5. Preferably, the compounds of the present invention have a pICso on a-SMA in phenotypic assay between 5 and 5.5. More preferably, the compounds of the present invention have a pICso higher than5.5

[0474] Furthermore, tested compound dose-dependently inhibits the collagen I deposition, after 72h of treatment.

[0475] These findings suggest that de novo synthesis of serine and glycine is required for pulmonary fibrosis; the inhibition of myofibroblast differentiation and collagen deposition is strongly correlated and necessary for the antifibrotic activity of the compounds.

[0476] BSEP inhibition

[0477] Method

[0478] BSEP inhibition was evaluated using cryopreserved human hepatocytes (Plateable Cryopreserved Human Hepatocytes, BIOIVT) cultured for 5 day between two layer of collagen (sandwich configuration). In this culture condition, hepatocytes express relevant transporters including BSEP and retain the bile canalicular structure.

[0479] On day 5 of culture, hepatic cells are ready for the assay and the biliary clearance of Taurocolic Acid (TCA), a known BSEP substrate, can be exstimated in presence and in absence of compound of interest.

[0480] The sample solution was prepared dissolving test compound and TCA in DMSO and then diluted in the Assay Buffer: Hank’s Balance Salt Solution (HBSS+) warmed at 37 °C before use, to give the 10 pM TCA working solution with and without 100 pM of test compound. Hepatocytes were incubated for 10 minutes with these working solutions allowing TCA to be excreted into bile. At the end of incubation, the working solution was aspirated, and the content of the bile was collected through the addition of HBSS Modified without Ca2+ / Mg2+(HBSS-). The presence of Ca2+in the buffer is required to maintain the integrity of the tight junctions, the diffusional barrier between the canalicular lumen and extracellular space. Instead, incubation of cells in Ca2+-free buffer disrupts the tight junctions and opens the bile canalicular structures, allowing the bile content to be released and collect for HPLC-MS / MS analysis.

[0481] The in vitro biliary clearance of TCA incubated with and without test compounds is calculated according to the following formula:

[0482] ClBil(|tL / min / mg protein) where

[0483] Acc. Bile = (TCA amount in HBSS (-) buffer samples (pmol / mg protein) * Volume of each samples (mL)) / Protein content per well (mg)

[0484] AUC = Incubation time (min) * TO Concentration. TO concentration is the initial TCA concentration in the medium.

[0485] The inhibition of BSEP was calculated as percentage of inhibition of TCA biliary clearance in presence of compound of interest, according to the following formula:

[0486] (TCA ClBiiwith test compound

[0487] BSEP inhibition% = 100 — TCA ClBn without test compo

[0488] The results for individual compounds are provided below in Table 19.

[0489] Table 19- BSEP inhibition for exemplified compounds

[0490] + 50-25% BSEP inhibition @ 100 uM Example concentration

[0491] ++: 25-13% BSEP inhibition @ 100 uM Example concentration

[0492] +++: <13% BSEP inhibition @ 100 uM Example concentration

[0493] Compounds according to this invention are characterized by an in vitro BSEP inhibition at 100 pM < 50 %, that can be considered suitable and acceptable from a safety point of view. Preferably, compounds showed BSEP inhibition values between 50 and 25%. More preferably, compounds showed BSEP inhibition values between 25 and 13%; most preferably, compounds showed BSEP inhibition at 100 pM below 13%.

[0494] Permeability

[0495] Method

[0496] The permeability of the compounds of the present invention was evaluated performing the assay on Caco-2 cells monolayers (human colon adenocarcinoma immortalized cell) by measuring the transport of compound (absorption and secretion) in both directions: apical to basolateral direction (A>B) and basolateral to apical (B>A) with and without PgP inhibitor (Elacridar).

[0497] The cells, purched from ReadyCell in 96 well format (Cod. KRECE-CCR50), were cultured by the supplier for 21 day on transwell supports in DMEM Ig / L glucose culture medium supplemented with Fetal Bovin Sierum (10%), Glutamine 200mM (1%) and Penicillin 10000 U / ml- 10 mg / ml Streptomycin (1%).

[0498] On day 21 of colture, cell monolayers integrity was verified by measuring the trans-epithelial electric resistance (TEER) using the EVOM equipment (Endohm, WPI, Germany) and studying the apparent permeability (Papp) of reference compounds (Sulpiride and Metoprolol). Furthermore, as a control, the Talinolol lOuM (Pgp efflux substrate) with and without Elacridar in both directions was used.

[0499] The sample solution was prepared dissolving test compound in DMSO at the concentration of 10 mM and then diluted in the Assay Buffer (Hank’s Balance Salt Solution) warmed at 37°C before use, to give the 10 pM Compound working solution with and without lOpM Elacridar. These working solutions were added to donor compartment (apical for A>B direction and basolateral for B>A direction ) and Assay Buffer (Hank’s Balance Salt Solution) to the receiver compartment (basolateral for A>B direction and apical for B>A direction ).The plate was incubated at 37°C for 120 min, all incubation were conducted in triplicates. At the end of incubation, samples from donor and receiver compartments were collected for HPLC-MS / MS analyses.

[0500] The permeability coefficients (Papp) in both directions: apical to basolateral (A>B) and basolateral to apical (B>A) with and without PgP inhibitor (Elacridar) was calculated in nm / sec, using the following equation:

[0501] Cr • Vr rnni]

[0502] Papp = - ; - 777 • 10000000 - t • A • CO LsecJ where:

[0503] Cr = measured concentration in the receiver well at the time t (expressed as IS ratio)

[0504] Vr = volume of the receiver well (ml) t = time (sec) A = membrane surface area (cm2)

[0505] CO =initial donor concentration

[0506] Passive Papp is considered Papp A>B with PgP inhibitor Elacridar.

[0507] The results for individual compounds are provided below in Table 20.

[0508] Table 20- passive permeability for exemplified compounds

[0509] As showed in Table 20, all the compound of the present invention demonstrated a passive permeability value > 15 nm / sec, which is considered suitable for an oral administration.

[0510] Comparative Examples Results

[0511] Comparative Example A

[0512] Comparative Example A is characterized by a small linear chain with two carbon atoms and a final morpholino group in position alpha to the carboxyl group, instead of a small linear chain with two carbon atoms and a final ORi group in position alpha to the COORe group, as the compounds of formula (I) of the invention and has been tested as described above along with the BSEP assays. Differently from the compounds of formula (I) of the present invention, the Comparative Example A shows a passive permeability of 2.8 nm / s and thus not suitable for an oral administration.

[0513] Comparative Example B

[0514] Comparative Example B is characterized by a small linear chain with three carbon atoms and a final ORi group in position alpha to carboxylic acid, instead of a small linear chain with two carbon atoms and final ORi group in position alpha to the COORe group, as the compounds of formula (I) of the invention, and has been tested as described above along with the BSEP assays.

[0515] Differently from the compounds of formula (I) of the present invention, the comparative Example B shows a B SEP inhibition of 82% at 100 pM tested concentration. Said inhibition cannot be considered acceptable for an oral drug candidate.

[0516] Comparative Example C

[0517] Comparative Example C is characterized by a small branched chain with three carbon atoms and by the absence of a final ORi group in position alpha to carboxylic acid, instead of a small linear chain with two carbon atoms and final ORi group in position alpha to the COORe group, as the compounds of formula (I) of the invention, and has been tested as described above along with the BSEP assays. Differently from the compounds of formula (I) of the present invention, the comparative Example C shows a B SEP inhibition of 81% at 100 pM tested concentration. Said inhibition cannot be considered acceptable for an oral drug candidate.

[0518] All the above results demonstrate that in the compounds of formula (I) of the present invention, the presence of a small linear chain with two carbon atoms and a final ORi group in position alpha to the COORe group, with Ri and R2 eventually fused together to form a -(Ce- C7)heterocycloalkyl, leads unexpectedly to a series of compounds that is active for IPF in the phenotypic assay, endowed with very good B SEP inhibition and permeability profile, thus suitable for treatment of fibrosis with a very promising bioavailability profile for oral administration.

Claims

CLAIMS1. A compound of formula (I)whereinRi is -(Ci-Ce)alkyl;R2 is H or -(Ci-Ce)alkyl, optionally substituted with OR7, or Ri and Rz are fused together to form a -(C6-C7)heterocycloalkyl;R3 is halogen;R,and R5 are independently H or selected from the group consisting of halogen, -OR7 and -(Ci-Ce)alkyl;Re and R7 are independently H or -(Ci-Ce)alkyl; and pharmaceutically acceptable salts thereof.

2. A compound of formula (I) according to claim 1, wherein Re is H, represented by the formula (la):whereinRi, Rz, R3, Rt, Rs and R7 are defined as in claim 1; and pharmaceutically acceptable salts thereof.

3. The compound of formula (I) according to claim 2, wherein R3 is chlorine, represented by the formula (lb):whereinRi, Rz, t, Rs and R7 are defined as in claim 1; and pharmaceutically acceptable salts thereof.

4. The compound of formula (I) according to claim 1-3, wherein:Ri is methyl;Rz is H or ethyl, optionally substituted with OR7, or Ri and Rz are fused together to form a tetrahydropyrane; and pharmaceutically acceptable salts thereof.

5. The compound of formula (I) according to claim 1-4, whereinR4 and R5 are independently H or selected from the group consisting of chlorine, fluorine, methoxy and methyl;R7 is H or methyl; and pharmaceutically acceptable salts thereof.

6. The compound according to any one of claims 1 to 5, selected from at least one of2-(4-(3-(4, 5-di chi oro-1 -methyl- lH-indole-2-carboxamido)tetrahy drofuran-3- yl)phenyl)-4-methoxybutanoic acid;2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-4-methoxybutanoic acid;Diastereoisomers 1 and 2 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;Diastereoisomer 1 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;Diastereoisomer 2 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;Diastereoisomers 3 and 4 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;Diastereoisomer 3 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;Diastereoisomer 4 of 2-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;2-(4-(3-(4, 5-di chi oro-1 -methyl- lH-indole-2-carboxamido)tetrahy drofuran-3- yl)phenyl)-4-methoxy-2-(2 -methoxy ethyl)butanoic acid;2-(4-(3-(4-chloro-5-fluoro- 1 -methyl- lH-indole-2-carboxamido)tetrahy drofuran-3- yl)phenyl)-4-methoxybutanoic acid;2-(4-(3-(4-chloro-l,5-dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-4-methoxybutanoic acid;2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)-4-methoxybutanoic acid;Diastereoisomer 1 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;Diastereoisomer 2 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid;4-(4-(3-(4-chloro-5-fluoro- 1 -methyl- lH-indole-2-carboxamido)tetrahy drofuran-3- yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;4-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;4-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Enantiomer 1 of 4-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Enantiomer 2 of 4-(4-(3-(4-chloro-5-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;4-(4-(3-(4-chloro-l,5-dimethyl-lH-indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Enantiomer 1 of 4-(4-(3-(4-chloro-l,5-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Enantiomer 1 of 4-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Enantiomer 1 of 4-(4-(3-(4-chl oro-5, 6-difluoro-l -methyl- lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Enantiomer 1 of 4-(4-(3-(4-chloro-5-fluoro-6-methoxy-l-methyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)tetrahydro-2H-pyran-4-carboxylic acid;Diastereoisomers 1 and 2 of 2-(4-(3-(4-chloro-l,6-dimethyl-lH-indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)-4-methoxybutanoic acid; as single deuterate, enantiomer, diastereoisomer or mixtures thereof, in any proportion, or pharmaceutically acceptable salts and solvates thereof.

7. An Intermediate Compound (XI) or the pharmaceutically acceptable salts thereof, for the preparation of the compound of formula (I) as defined in claim 1, having formula:wherein Ri, Rz, Re are as defined in claims 1 to 6.

8. Use of the Intermediate compound (XI) , as defined in claim 7, in the preparation of a compound of formula (I) according to any one of claims 1 to 6.

9. A pharmaceutical composition comprising a compound of formula (I) according to any one of claims 1 to 6, in admixture with one or more pharmaceutically acceptable carrier or excipient.

10. A compound of formula (I) according to any one of claims 1-6 or a pharmaceutical composition according to claims 9 for use as a medicament.

11. A compound of formula (I) according to claims 1 to 6 or a pharmaceutical composition according to claims 9 for use according to claim 10 in the prevention and / or treatment of fibrosis and / or diseases, disorders, or conditions that involve fibrosis.

12. A compound of formula (I) or a pharmaceutical composition for use according to claim 11 in the prevention and / or treatment of fibrosis including pulmonary fibrosis, idiopathic pulmonary fibrosis (IPF), hepatic fibrosis, sarcoidosis, familiar pulmonary fibrosis, chronic hypersensitivity pneumonitis (CHP), kidney or renal fibrosis, ocular fibrosis, cardiac fibrosis, arterial fibrosis and systemic sclerosis.

13. A compound of formula (I) or a pharmaceutical composition for use according to claim 12 in the prevention and / or treatment idiopathic pulmonary fibrosis (IPF).

14. The pharmaceutical composition for use according to claim 10-13 for oral administration.

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