Thieno-indole amide derivatives as phgdh inhibitors

Abstract

The present invention generally relates to compounds of formula (I) inhibiting 3-phosphoglycerate dehydrogenase (PHGDH) activity; particularly, the invention relates to compounds that are thieno-indole amide derivatives, including pharmaceutically acceptable salts thereof, methods of preparing such compounds, and therapeutic use thereof. The compounds of the invention may be useful for instance in the treatment of many disorders associated with PHGDH, for instance in the treatment of many disorders associated with fibrosis, such as idiopathic pulmonary fibrosis (IPF).

Description

[0001] THIENO-INDOLE AMIDE DERIVATIVES AS PHGDH INHIBITORS

[0002] FIELD OF THE INVENTION

[0003] The present invention generally relates to compounds inhibiting 3 -phosphoglycerate dehydrogenase (hereinafter PHGDH) receptor; the invention relates to compounds that are of thieno-indole amide derivatives, including pharmaceutically acceptable salts thereof, methods of preparing such compounds, and therapeutic use thereof.

[0004] The compounds of the invention may be useful for instance in the treatment of many disorders associated with fibrosis, such as idiopathic pulmonary fibrosis (IPF).

[0005] BACKGROUND OF THE INVENTION

[0006] 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 YangM., Vousden, KH, Nature Reviews Cancer 2016,16, 650 662).

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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).

[0011] Various compounds have been described in the literature as PHGDH inhibitors.

[0012] Raze Therapeutics disclosed in various patent applications (for example WO2017156165 or WO2017156179) 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.

[0013] Boehringer Ingelheim disclosed in patent application WO 2018167019 tosylacetate based compounds and derivatives which are effective as PHGDH inhibitors and their use in the treatment of PHGDH-mediated disorders, such as treatment and / or prevention of cancer, infections, inflammations or autoimmune diseases.

[0014] Alternative PHGDH inhibitors, promising for the prevention and / or treatment of fibrosis, were described as noncompetitive inhibitors or allosteric inhibitors of PHGDH enzyme (see Pacold et al, Nat Chem Biol. 2016; 12: 452-458).

[0015] Examples of said PHGDH inhibitors useful for treating fibrotic diseases are disclosed in WO2016115463 (Whitehead Institute For Biomedical Research; Dana-Farber Cancer Institute, Inc).

[0016] 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).

[0017] 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.

[0018] 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).

[0019] About 3 million people are affected globally and IPF seems to become more common over the year, the incidence is expected to double by 2030 (see Fernandex Perez ER, et al, Chest, 2020; 137:129-137). Mortality is comparable to lung cancer, the median survival is 2-3 years after diagnosis, and respiratory failure is the most common cause of death (see Strongman H, et a., Adv Ther. 2018;35: 724-736).

[0020] The currently two FDA-approved drugs on the market, Nintedanib and Pirfenidone, slow the progression of the disease and prolong the life expectancy of IPF patients; however, the treated patients continue to experience lung function loss and premature death and the adverse events of both Nintedanib and Pirfenidone critically affect the patient’s quality of life.

[0021] The IPF is therefore a high unmet medical need and many efforts have been done in the recent past years to develop alternative treatments.

[0022] Despite the above prior art, there remains a potential for developing medicaments comprising a PHGDH inhibitor useful for the prevention and / or treatment of fibrosis, in particular IPF.

[0023] The underlying problem of the present invention therefore lies in the provision of a medicament comprising a compound of formula (I) for the prevention and / or treatment of fibrosis, in particular IPF.

[0024] The state of the art does not describe or suggest that thieno-indole amide derivatives of general formula (I) of the present invention which may represent a solution to the afore mentioned unmet medical need.

[0025] SUMMARY OF THE INVENTION

[0026] In a first aspect the invention refers to a compound of formula (I) wherein:

[0027] Ri is -(Ci-Ce)alkyl, optionally substituted with -(C3-C7)heterocycloalkyl, wherein such -(C3- C7)heterocycloalkyl is optionally substituted with -(Ci-Ce)alkyl;

[0028] R2 and R3 are independently H or -(Ci-Ce)alkyl, optionally substituted with -ORs, or R2 and Rj are fused together to form a -(C3-C6)cycloalkyl or -(C3-C7)heterocycloalkyl;

[0029] R4 or R5 are independently H or -(Ci-Ce)alkyl;

[0030] Li is a covalent bond or a -(CO)-NR2R3- group, or -(Ci-Ce)alkylene group optionally substituted with ORs, wherein when Li is -(CO)-NR2R3- and Rz and Rj are fused together in a -(C3- C7)heterocycloalkyl, the carboxyl group -(C0)-0-R4 of formula (I) is linked to anyone of the C atom of such -(C3-C7)heterocycloalkyl; and pharmaceutically acceptable salts thereof.

[0031] In a second aspect, the invention refers to pharmaceutical composition comprising a compound of formula (I) in a mixture with one or more pharmaceutically acceptable carrier or excipient.

[0032] In a third aspect, the invention refers to a compound of formula (I) for use as a medicament.

[0033] 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.

[0034] In a further aspect, the invention refers to a compound of formula (I) for use in the prevention and / or treatment idiopathic pulmonary fibrosis (IPF) DETAILED DESCRIPTION OF THE INVENTION

[0035] Unless otherwise provided, the term “compound of formula (I)” comprises in its meaning stereoisomers, tautomers, deuterated and pharmaceutically acceptable salts or solvates thereof.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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. For compounds disclosed in the Examples comprising one or more stereocenters, if specific stereochemistry is not shown, the compound is intended to include a mixture of stereoisomers.

[0042] The term “stereocenter” refers to an atom with three or more different attachments, wherein interchanging of two of these attachments leads to another stereoisomer. Examples include, but are not limited to, an sp3 (tetrahedral) carbon atom bearing four different attachments.

[0043] The term "enantiomer" refers to one of a pair of molecular species that are mirror images of each other and are not superimposable.

[0044] The term "diastereomer " refers to stereoisomers that are not mirror images. 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.

[0045] 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.

[0046] 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)).

[0047] 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.

[0048] The term "deuterium" refers to the isotopic deuterium of hydrogen (H).

[0049] 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.

[0050] The term “halogen” or “halogen atoms” or “halo” as used herein includes fluorine, chlorine, bromine and iodine atom.

[0051] 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.

[0052] The term "(Cx-Cy)alkylene" wherein x and y are integers, refers to a straight or branched “(Cx-Cy)alkyl” radical having in total two unsatisfied valences. Example of such "(Cx-Cy)alkylene" groups may include for example a divalent methylene radical, a divalent ethylene radical and -CH- CH2(CH3)2.

[0053] 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.

[0054] 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.

[0055] 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 piperazinyl, pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, thiomorpholinyl, pyrrolinyl, dihydro- or tetrahydro-thiazolyl, oxetanyl, tetrahydropyranyl, pyranyl, dihydro- or tetrahy dro-furanyl .

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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)-.

[0062] A dash (“-”) that is not between two letters or symbols is meant to represent the point of attachment for a substituent. 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.

[0063] The term “pICso” refers to the negative logarithm of the ICso value expressed as molar concentration.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] As above indicated, the present invention refers to a series of compounds represented by the general formula (I), as herein below described in detail, which are endowed with an inhibitory activity versus 3 -phosphoglycerate dehydrogenase (hereinafter defined as PHGDH) receptor.

[0068] 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).

[0069] As indicated in the experimental part, the compounds of formula (I) of the invention have an activity as shown in Table 22, wherein for each compound tested in the High NAD+biochemical assay is reported the potency expressed as pICso.

[0070] As it can be appreciated, all the compounds of the present invention according to Table 22, show a potency with respect to their inhibitory activity on receptor PHGDH higher than 5.5 in high NAD+ conditions assay.

[0071] Some representative compounds of formula (I) were tested also in a cellular serine flux assay based on13C3-Serine MS read out, using breast cancer cells lines (MDA-MB468). PHGDH is a key enzyme for Serine biosynthesis, and it is described that breast cancer cells (MDA-MB468) can be dependent on PHGDH for their growth and survival. In the cellular assay mentioned above representative compounds tested demonstrated good inhibitory activity of the PHGDH receptor, as reported in Table 23. Accordingly, the compounds of formula (I) can be used in the treatment of fibrosis, and in particular treatment of idiopathic pulmonary fibrosis, whenever PHGDH receptors are involved.

[0072] Thus, in one aspect the invention refers to a compound of formula (I) wherein

[0073] Ri is -(Ci-Ce)alkyl, optionally substituted with -(C3-C7)heterocycloalkyl, wherein such -(C3- C7)heterocycloalkyl is optionally substituted with -(Ci-Ce)alkyl;

[0074] R2 and Rj are independently H or -(Ci-Ce)alkyl, optionally substituted with -ORs, or R2 and R3 are fused together to form a -(C3-C6)cycloalkyl or -(C3-C7)heterocycloalkyl;

[0075] R4 or R5 are independently H or -(Ci-Ce)alkyl;

[0076] Li is a covalent bond or a -(CO)-NR2R3- group, or -(Ci-Ce)alkylene group optionally substituted with ORs, wherein when Li is -(CO)-NR2R3- and R2 and R3 are fused together in a -(C3- C7)heterocycloalkyl, the carboxyl group -(C0)-0-R4 of formula (I) is linked to anyone of the C atom of such -(C3-C7)heterocycloalkyl; and pharmaceutically acceptable salts thereof.

[0077] All the listed groups for each of the variable moieties Ri, R2, R3, R>, Rs and Li 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.

[0078] The aromatic tricyclic ring is composed by an indole ring, that is fused to a thiophene to give a thieno[2,3-b]indole, which has a substituted amine group on the thiophene ring.

[0079] In one embodiment, Ri is -(Ci-Ce)alkyl, optionally substituted with -(C3- C7)heterocycloalkyl, wherein such -(C3-C7)heterocycloalkyl is optionally substituted with -(Ci- Ce)alkyl. In a preferred embodiment, Ri is -(Ci-C4)alkyl, optionally substituted with -(C3- C6)heterocycloalkyl, wherein such -(C3-C6)heterocycloalkyl is optionally substituted with -(Ci- C4)alkyl. In a more preferred embodiment, Ri is methyl or ethyl, optionally substituted with an - (C3-C6)heterocycloalkyl, wherein such -(C3-C6)heterocycloalkyl is optionally substituted with methyl. In an even more preferred embodiment, Ri is methyl or ethyl, optionally substituted with a methylpiperazine. In one embodiment, Rz and R3 are independently H or -(Ci-Ce)alkyl, optionally substituted with -ORs, or R2 and R3 are fused together to form a -(C3-C6)cycloalkyl or -(C3- C7)heterocycloalkyl. In a preferred embodiment, Rz and Rj are independently H or -(Ci-C4)alkyl, optionally substituted with -ORs, or Rz and R3 are fused together to form a -(C3-C5)cycloalkyl or -(C3-C6)heterocycloalkyl. In one more preferred embodiment, Rz and Rj are independently H or methyl, optionally substituted with -OH.

[0080] In another preferred embodiment, Rz and Rj are fused together to form a -(C3-Ce)cycloalkyl selected from cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl. In a more preferred embodiment Rz and Rj are fused together in a cyclobutyl or cyclopentyl.

[0081] In another preferred embodiment, Rz and Rj are fused together to form a -(C3- C6)heterocycloalkyl. In a more preferred embodiment, Rz and Rj are fused together to form a tetrahy drofurane .

[0082] In one embodiment, R4 or R5 are independently H or -(Ci-Ce)alkyl. In a preferred embodiment, Rj or R5 are independently H or -(Ci-C4)alkyl. In a preferred embodiment, Ri is H. In another preferred embodiment, Riis -(Ci-C4)alkyl. In a more preferred embodiment, Riis H or methyl.

[0083] In another preferred embodiment, R5 is H or -(Ci-C4)alkyl. In a more preferred embodiment, Rs is H or methyl. In a even more preferred embodiment, R5 is H.

[0084] In one embodiment, Li is a covalent bond or a -(CO)-NRzR3- group, or -(Ci-Ce)alkylene group optionally substituted with ORs, wherein when Li is -(CO)-NRzR3- and Rz and Rj are fused together in a -(C3-C7)heterocycloalkyl, the carboxyl group -(CO)-O-R4 of formula (I) is linked to anyone of the C atom of such -(C3-C7)heterocycloalkyl;.

[0085] In a preferred embodiment, Li is a covalent bond. In another preferred embodiment, Li is a -(Ci-Ce)alkylene, optionally substituted with ORs. In a more preferred embodiment, Li is a -(Ci- C4)alkylene, optionally substituted with ORs. In a more preferred embodiment, Li is methylene or ethylene, optionally substituted with OMe. In another more preferred embodiment, Li is isobutylene. In another preferred embodiment, Li is -(CO)-NRzR3- and Rz and Rj are fused together to form a -(C3-C6)heterocycloalkyl, and the carboxyl group -(CO)-O-R4 of formula (I) is linked to anyone of the C atom of such -(C3-C7)heterocycloalkyl.

[0086] In a more preferred embodiment, Li is:

[0087] In a more preferred embodiment, Li and -(CO)-O-R4 form an L-proline. All the preferred groups listed above for each of the variable moieties Ri, Rz, Rj, R, Rs, and Li of the compounds of the invention may be combined with each other in embodiments which are included in the scope of the invention.

[0088] In another preferred embodiment, the invention refers to a compound of formula (I) as PHGDH inhibitor, wherein R4 is H, represented by the general formula (la) wherein Ri, R2, R3, Rs and Li are defined as above.

[0089] In a preferred embodiment, the invention refers to a compound of formula (I) or a compound of formula (la) as PHGDH inhibitor, wherein:

[0090] Ri is selected from methyl or ethyl, optionally substituted by methyl-piperazine;

[0091] Rz and R3 are independently H or methyl, optionally substituted by -OH, or are fused together in a tetrahydrofurane, cyclopentane or cyclobutane;

[0092] R4 is H; R5 is H or methyl; and pharmaceutically acceptable salts thereof.

[0093] In a preferred embodiment, the invention refers to at least one of the compounds listed in Table 1 below and pharmaceutically acceptable salts thereof.

[0094] Table 1 - List of preferred compounds

[0095] 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.

[0096] In a preferred embodiment, the invention refers to a compound of formula (I) as PHGDH inhibitor, wherein Li is -(CO)-NR2R3-, R2 and R3 are fused together in a -(C3-C7)heterocycloalkyl, represented by the general formula (Ib) wherein Ri, R2, R3, R> and R5 are defined as above. In a more preferred embodiment, the invention refers to a compound of formula (I) as PHGDH inhibitor, wherein Li is -(CO)-NR2R3-, represented by the general formula (Ic) wherein Ri, R2, R3, t, Rs are defined as above.

[0097] In an even more preferred embodiment, the invention refers to a compound of formula (I) as

[0098] PHGDH inhibitor, wherein Li is -(CO)-NR.2R.3-, represented by the general formula (Id) wherein Ri, R2, R3, t, Rs are defined as above.

[0099] All the preferred groups listed above for each of the variable moieties Ri, R2, R3, R4, Rs and Li of the compounds of the invention may be combined with each other in embodiments which are included in the scope of the invention.

[0100] In another embodiment, the invention refers to a compound of formula (I) as PHGDH inhibitor. In this respect, it has been found that the compounds of formula (I) of the present invention have an inhibitor drug potency in the high NAD+conditions assay, expressed as pICso on PHGDH receptor, equal or higher than 5.5.

[0101] Preferably, the compounds of the present invention have a pICso on PHGDH in high NAD+conditions assay between 5.5 and 6.0. More preferably, the compounds of the present invention have a pICso on PHGDH between 6.0 and 7.0. Most preferably, the compounds of the present invention have a pICso on PHGDH higher than 7.0.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] Preferably, the compounds of the present invention are administered orally or by inhalation.

[0108] In a more preferred embodiment, the compounds of the present invention or their pharmaceutical compositions are administered orally.

[0109] In another preferred embodiment, the compounds of the present invention or their pharmaceutical compositions are administered by inhalation.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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. 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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 jet or ultrasonic nebulizers known from the prior art or by soft-mist nebulizers.

[0119] The compounds of the invention can be administered as the sole active agent or in combination with other pharmaceutical active ingredients.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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. 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).

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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).

[0128] 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).

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] More preferably, the compounds of formula (I) of the present invention are useful for the treatment of idiopathic pulmonary fibrosis (IPF).

[0136] In a more preferred embodiment, the fibrotic disease mentioned above is IPF.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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).

[0141] 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.

[0142] 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

[0143] 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.

[0144] 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.

[0145] 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.

[0146] List of Abbreviations

[0147] 1H-NMR: Proton nuclear magnetic resonance;

[0148] 2-MeTHF : 2-m ethyltetrahydrofuran;

[0149] AA powder: (L-Asp acid; L-Asparagin; L-Glutamic acid; Hydroxy L-Proline; L-Proline); ab.: antibody;

[0150] ACN: acetonitrile;

[0151] ACN-d3 : deuterated acetonitrile;

[0152] AcOH: Acetic acid;

[0153] AIBN: azobisisobutyronitrile;

[0154] AUC: area under the curve;

[0155] Bn: benzyl;

[0156] Boc: tert-butyloxycarbonyl;

[0157] BOC2O: Di-tert-butyl dicarbonate;

[0158] BSA: Bovine Serum Albumin;

[0159] BTIB = Bis(trifluoroacetoxy)iodobenzene. c.a.: commercially available;

[0160] CDC13 : deuterated chloroform;

[0161] Clnii: biliary clearance;

[0162] CV: Column Volumes; dba: dibenzylideneacetone;

[0163] DCE: 1,2-di chloroethane;

[0164] DCM: Dichloromethane; de: diastereomeric excess; DIAD: diisopropyl azodicarboxylate;

[0165] DIBAL-H: Diisobutylaluminium hydride;

[0166] DIPEA: N,N-Diisopropylethylamine;

[0167] DMA: dimethylacetamide;

[0168] DMAP: 4-dimethylaminopyridine;

[0169] DMEM: Dulbecco's Modified Eagle Medium;

[0170] DMF : N,N-Dimethylformamide;

[0171] DMSO: Dimethyl sulfoxide;

[0172] DMSO-d6: deuterated dimethyl sulfoxide; ee: enantiomeric excess; eq.: equivalents;

[0173] EtOAc: Ethyl acetate;

[0174] FBS: Fetal Bovine Serum;

[0175] FCC: Flash column chromatography; h: hour / s;

[0176] HATU: l-[Bis(dimethylamino)methylene]-lH-l,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate);

[0177] HCOOH: formic acid;

[0178] HPLC: high pressure liquid chromatography;

[0179] HPLC-MS / MS: high pressure liquid chromatography-mass spectrometry / mass spectrometry;

[0180] LC: liquid chromatography;

[0181] LC-MS: Liquid Chromatography / Mass Spectrometry;

[0182] LDA: lithium diisopropylamide;

[0183] LG: leaving group;

[0184] LiHMDS: Lithium bis(trimethylsilyl)amide;

[0185] MEM: Minimal Essential Medium;

[0186] MeOH: methyl alcohol; min = minute / s; min: minute / s;

[0187] MPLC: medium-pressure liquid chromatography;

[0188] Ms: mesyl (MsCl: mesylchloride);

[0189] NaHMDS: sodium bis(trimethylsilyl)amide;

[0190] NCE: new chemical entity;

[0191] NHLF: Normal Human Lung Fibroblast; NMR: nuclear magnetic resonance; on: overnight;

[0192] P / S: Penicillin-Streptomycin;

[0193] PBS: Phosphate Buffered Saline;

[0194] Pd2(dba)s: Tris(dibenzylideneacetone)dipalladium(0); pen / strep: Penicillin-streptomycin;

[0195] PGn: protecting group;

[0196] PgP: P -glycoprotein;

[0197] PTS: p-toluenesulfonic acid; tR: Retention time;

[0198] RT : Room temperature; sat aq: saturated aqueous;

[0199] SCX: strong cation exchange;

[0200] SDS: Sodium Dodecyl Sulfate;

[0201] SFC: supercritical fluid chromatography;

[0202] SFC-MS: supercritical fluid chromatography-mass spectrometry;

[0203] SiliaMetS DMT = Metal scavenger;

[0204] SN: nucleophilic substitution;

[0205] TBME: tert-Butyl methyl ether;

[0206] TBS: TRIS-buffered saline;

[0207] TEA: Triethylamine;

[0208] TFA: Trifluoroacetic acid;

[0209] TGFP: Transforming Growth Factor-B;

[0210] TGX-gel : Tris-Glycine extended- Gels;

[0211] THF: Tetrahydrofuran;

[0212] TLC: Thin-layer chromatography;

[0213] TsOH: p-toluenesulfonic acid;

[0214] UPLC®: Ultra Performance Liquid Chromatography;

[0215] XPhos: Dicyclohexyl[2',4',6'-tris(propan-2-yl)[l,l'-biphenyl]-2-yl]phosphane; a-SMA: alpha-smooth muscle actin;

[0216] General Synthetic Procedures

[0217] 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).

[0218] The compounds of formula (I) and (la), 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).

[0219] Amine Intermediates (IV) can be commercially available or can be prepared according to Scheme 1, starting from benzylamines (II) protected with a suitable protecting group (PGi), which can be removed without affecting group OR4 in reaction conditions known by the skilled person. Such PGi can be for example a carbamate, such as for example tert-butyl oxy carbonyl (Boc) or others. Intermediates (II) have a benzoic acid function which can be exploited in amide coupling reactions yielding Intermediates (III). Such amidic couplings involve activation of benzoic acid, for example by conversion into corresponding acyl halide, such as for example acyl chloride, or by the use of amide coupling reagents, such as for example HATU or others. Couplings can take place in the presence of a base, such as for example TEA or DIPEA or others, in suitable solvents, such as for example DMF, THF, DCM or others or mixtures thereof. Wherein in Intermediates (III) Li is a methylene group, such Intermediates (III) can be converted into Intermediates (IILa) by alpha-alkylation 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 haloalkyls, such as for example alkylbromides or alkyliodides or others. In another embodiment, other leaving groups instead of halides can be considered in such alkylation reaction, such as for example mesylates or others. Suitable solvents for the reaction converting Intermediates (III) into Intermediates (IILalk) can be selected for example from DMF, DMA, DMSO, THF, 1,4-di oxane or others, or mixtures thereof. It should be noted that Intermediates (IILalk) and subsequent intermediates can exist as mixtures of enantiomers or diastereoisomers, depending on the nature of R2 and R3 substituents. Intermediates (IV) can then be obtained by acidic treatment of Intermediates (III) or Intermediates (IILalk), for example by the use of an acid such as for example HC1 or TFA or others, in suitable solvents such as DCM, 1,4-di oxane, alcohols or others, or mixtures thereof. Intermediates (IV) can be isolated as salts and used as they are in next steps, or can be isolated and used as free amines.

[0220] Scheme 1

[0221] (lll-alk)

[0222] Wherein R2, R3, R4, Li are defined as above.

[0223] In another embodiment, Intermediates (IV) can be obtained according to Scheme 2, starting from suitable Intermediates (V), that can be prepared according to procedures reported in WO 2017156165 or are commercially available. Intermediates (V) can be converted into Intermediates (VI) according to Pd-catalysed decarboxylative cross-couplings reported in WO2017156165. Alternatively, Intermediates (VI) can be obtained by suitable Pd-catalysed cross-coupling reactions, such as for example Suzuki cross-couplings or others, reacting Intermediates (V) 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 (VI) by reacting Intermediates (V) 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 (VI) can then be transformed into Intermediates (Vl-alk) by alkylation 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 haloalkyls, such as for example alkylbromides, alkyliodides or others. Alternatively, other leaving groups instead of halides can be considered in such alkylation reaction, such as for example mesylates or others. Suitable solvents for the reaction converting Intermediates (VI) into Intermediates (Vl-alk) can be selected for example from DMF, DMA, DMSO, THF, 1,4-di oxane or others, or mixtures thereof. Nitrile group in Intermediates (VI) or Intermediates (Vl-alk) can then be converted into amidic group of Intermediates (VII) and subsequently to amine group of Intermediates (IV) by synthetic sequences described in WO2017156165, or by methods well known to those skilled in the art.

[0224] Scheme 2

[0225] (Vl-alk)

[0226] Wherein R2, R3, R4, Li are defined as above.

[0227] Single enantiomers (Va) and (Vb) can be isolated from racemic Intermediate (V) according to Scheme 3, by means of chiral separation techniques, such as chiral column chromatography or simulated moving bed chromatography or others. Enantiopure Intermediates (Va) and (Vb) can then be converted into subsequent intermediates by applying the same synthetic sequence disclosed in Scheme 2, finally leading to Intermediates (IVa) and (IVb) respectively.

[0228] Scheme 3

[0229] Wherein R2, R3, Ri, Li are defined as above.

[0230] In another embodiment, Intermediates (IV) can be prepared according to synthetic sequence reported in Scheme 4, starting from 2-amino-2-(4-bromophenyl)ethan-l-ol (VIII). Intermediate (VIII) or its hydrochloride salt can be converted into Intermediate (IX), for example by reaction with BOC2O, eventually in presence of a suitable base, such as for example TEA or others, in a suitable solvent or solvent mixture, such as for example DCM, alcohols or mixtures thereof. Intermediate (X) can be obtained by treatment of Intermediate (IX) with 2,2-dimethoxypropane in acidic conditions, such as for example in the presence of TsOH or other acids, in a suitable solvent, such as for example acetone or others. Intermediate (X) can be converted into corresponding intermediate (XI) with Pd-catalysed cross-coupling reactions, such as for example Suzuki crosscouplings or others, reacting Intermediates (X) 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 crosscouplings can yield Intermediates (XI) by reacting Intermediates (X) 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, an ethyl ester or a tert-butyl ester or others. Intermediates (XI) can then be transformed into Intermediates (XII) by alphaalkylation to ester group. Such alkylation reaction 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 haloalkyls, such as for example alkylbromides or alkyliodides or others. In another embodiment, other leaving groups instead of halides can be considered in such alkylation reaction, such as for example mesylates or others. Suitable solvents for the reaction converting Intermediates (XI) into Intermediates (XII) can be selected for example from DMF, DMA, DMSO, THF, 1,4-di oxane or others, or mixtures thereof. Intermediates (IV) can be obtained by acidic treatment of Intermediates (XII), or directly from Intermediates (XI) when the alpha-alkylation step is not required. Conversion of Intermediates (XII) and (XI) to Intermediates (IV) can be promoted for example by the use of HC1, or TFA or other acids in solvents such as DCM, 1,4-di oxane, alcohols, or others, or mixtures thereof. Intermediates (IV) can be isolated as HC1 or TFA salts and used as they are in next steps, or can be isolated and used as free amines. Scheme 4

[0231] Wherein R2, R3, R4, Li are defined as above.

[0232] Carboxylic acids (XVII) can be commercially available or can be prepared according to Scheme 5, starting from commercially available 2-chloro-lJ / -indole-3-carbaldehyde (XIII). Intermediate (XIII) can be converted into protected Intermediate (XIV) according to literature procedures (M. Suchy et al. Tetrahedron Letters (2001), 42(39), 6961-6963). Protecting group PG2 can be for example a carbamate, such as for example tert-butyl oxy 1 carbonyl or others. Treatment of Intermediates (XIV) with suitably PGs-protected 2-mercaptoacetates, such as for example methyl 2-mercaptoacetate or others, in suitable solvents such as alcohols or others, from RT to reflux, yields Intermediates (XV). Intermediates (XV) can be converted in Intermediates (XVI), by alkylation reactions, such as for example SN reactions or Mitsunobu reactions or others. Such Mitsunobu reactions can be run in the presence of suitable alcohols and Mitsunobu reactionpromoting reagents, such as for example (tributyl-V-phosphanylidene)acetonitrile or DI AD / PPhs system or others, in suitable solvents, such as for example toluene, THF or others. Intermediates (XVII) can then be obtained from Intermediates (XVI) by ester function cleavage, for example in acidic conditions such as for example in the presence of HC1 or TFA or other acids, or in basic conditions, such as for example 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. Scheme 5

[0233] Wherein Ri, is defined as above.

[0234] According to Scheme 6, Intermediates (XVII) can be condensed with Intermediates (IV) or (IVa) or (IVb), as free amine or salts, through in situ activation of carboxylic acid function, for example as an acylchloride or by the use of coupling reagents, 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 compounds of formula (I). Compounds of general formula (I) can be converted into compounds of formula (la) by ester function cleavage, for example in acidic conditions such as for example in the presence of HC1 or TFA or other acids, or in basic conditions, such as for example 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. Alternatively, compounds of formula (la) can be obtained directly from Intermediates (XVII) and (IV) by using crude esters, as for Example (I). In some embodiments, specific Examples (I) can be obtained from Examples (la) through the same amidation reactions described above for the condensation of Intermediates (XVII) with Intermediates (IV). Scheme 6

[0235] Wherein Ri, R2, R3, t, Li are defined as above.

[0236] Compounds of formula (la) can exists as mixtures of stereoisomers, as can be appreciated in Scheme 7. One or more stereocenters can be present in compounds of formula (I) at the C atom bearing R2 and R3 substituents and / or in the Li wherein Li is not a covalent bond. In such cases, single stereoisomers can be obtained by chiral resolution techniques, such as for example chiral column chromatography. Alternatively, Examples of formula (la) can be properly derivatised with protecting groups PG4 to yield Intermediates (XVIII), where PG4 is selected to facilitate chiral resolution and to be cleaved in conditions unaffecting optical purity of stereocentres. PG4 can be for example a 'butyl group or an allyl group or others, and can be inserted for example, in the case of allyl group, through alkylation of carboxylic group by allylbromide in the presence of a base, or by condensation with allyl alcohol in the presence of coupling reagents, such as for example carbonyl diimidaziole or others, thus yielding Intermediates (XVIII). Single stereoisomers are then isolated from Intermediates (XVIII) through chiral separation techniques. Finally, stereopure Examples can be obtained from corresponding stereopure Intermediates (XVIII) by cleavage of group PG4. This can be accomplished for example, when PG4 is an allyl group, in a Pd-mediated cleavage reaction in the presence of an allyl group scavenger, such as for example morpholine or other nucleophiles. Scheme 7

[0237] Wherein Ri, Rz, R3, and Li are defined as above.

[0238] Exemplified preparation processes are given in the following experimental part.

[0239] General Experimental Details

[0240] Purifications

[0241] Purification by “chromatography”, “flash chromatography” or “flash column chromatography (FCC)” refers to purification using an Interchim PuriFlash Compact 420 or PuriFlash XS420 purification system, or Biotage Isolera or equivalent LC intrument using a prepacked polypropylene column containing stationary phase (cartridge). Where products were purified using a Si cartridge, this refers to an Interchim (or equivalent) pre-packed polypropylene column containing unbounded activated silica with spherical particles with average size of 50 pm (SIHP 50). Fractions containing the desired product (identified by TLC and / or LC-MS analysis) were pooled and concentrated in vacuo.

[0242] NMR Methods

[0243] NMR spectra were obtained on a Bruker Avance III 600 (5 mm RT inverse probe head), Bruker DRX 500, Bruker Avance III HD 400 MHz (5 mm RT inverse probe head) or Bruker Fourier 300 HD 300 MHz spectrometers using standard Bruker pulse sequences. DMSO-d6, d4- MeOD 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 tetramethyl silane 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.

[0244] In some cases, signals NH from amide bond or amine bond (Exchangeable protons) are not visible. In a few cases, some signals could be hidden under the signal of water or under the signal of DMSO or other residual solvents.

[0245] LC / UV / MS Analytical Methods

[0246] LC-MS retention times are estimated to be affected by an experimental error of ± 0.5 min.

[0247] Method 1

[0248] Method 1 was performed on Dionex UHPLC Ultimate 3000 with DAD detector / Thermo Scientific MSQ Plus; Column: Kinetex ® 2.6 pm XB C18 (4.6x50mm), I lOA, mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in acetonitrile. Gradient conditions are reported in Table 2.

[0249] Table 2: Method 1 conditions

[0250] Column temperature: 25 °C; UV detection: from 190 nm to 340 nm; MS conditions: Ionisation Mode: alternate-scan Positive and Negative Electrospray (ES+ZES-), Scan Range: 100 to 1000 AMU.

[0251] Method 2

[0252] Method 2 was performed on Waters ACQUITY UPLC ® I-Class PLUS System with Waters SQ Detector 2; Column: Acquity UPLC ® BEH C18 1.7 pm (2.1 x 100 mm), mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in acetonitrile; Gradient conditions are reported in Table 3. Table 3: Method 2 conditions

[0253] Column temperature: 40 °C; UV detection: from 200 nm to 400 nm; MS conditions: Ionisation Mode: alternate-scan Positive and Negative Electrospray (ES+ZES-), Scan Range: 100 to 1000 AMU. Method 3

[0254] Method 3 was performed on Waters Acquity H-Class UPLC® System; Column: Acquity C18 CSH (2.1x50mm), mobile phase A: 0.1% formic acid in water, mobile phase B: acetonitrile. Gradient conditions are reported in Table 4.

[0255] Table 4: Method 3 conditions Column temperature: 60 °C; UV detection: from 210 nm to 400 nm; injection volume: 1 microlitro; MS conditions: Ionisation Mode: alternate-scan Positive and Negative Electrospray (ES+ / ES-), Scan Range: 100 to 1000 AMU.

[0256] Method 4

[0257] Method 4 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: 0.05% (v / v) ammonia in water, mobile phase B: 0.05% (v / v) ammonia in acetonitrile. Gradient conditions are reported in Table 5.

[0258] Table 5: method 4 conditions 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.

[0259] Method 4a

[0260] Method 4a 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. Gradient conditions are reported in Table 6.

[0261] Table 6: method 4a conditions

[0262] 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.

[0263] Method 5

[0264] Method 5 was performed on Acquity UPLC ® coupled with SQD mass spectrometer; Column: Acquity BEH Cl 8 (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. Gradient conditions are reported in Table 7.

[0265] Table 7: Method 5 conditions

[0266] 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.

[0267] Method 6

[0268] Method 6 was performed on 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; Gradient conditions are reported in Table 8.

[0269] Table 8: method 6 conditions

[0270] 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.

[0271] Method 7

[0272] Method 7 was performed on AGILENT Infinity 1260 LC System coupled with SFC and Agilent 6540B UHD Accurate-Mass Q-TOF 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: acetonitrile. Gradient conditions are reported in Table 9.

[0273] Table 9: Method 7 conditions

[0274] Column temperature: 40 °C; UV detection: from 190 nm to 400 nm; MS conditions: Ionisation Mode: Positive or Negative (Dual AJS ESI), Scan Range: 100 to 1000 AMU. Method 8

[0275] Method 8 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. Gradient conditions are reported in Table 10. Table 10: method 8 conditions

[0276] 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 9

[0277] Dionex UHPLC Ultimate 3000 with DAD detector / Thermo Scientific ISQ EC - Mass Spectrometer; Column: Kinetex ® 2.6 pm XB C18 (4.6x50mm), I lOA, mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in acetonitrile; Gradient conditions are reported in Table 11.

[0278] Table 11: Method 9 conditions

[0279] Column temperature: 25 °C; UV detection: from 190 nm to 340 nm; MS conditions: Ionisation Mode: alternate-scan Positive and Negative Electrospray (ES+ZES-), Scan Range: 100 to 1000 AMU.

[0280] Method 10 Dionex UHPLC Ultimate 3000 with DAD detector / Thermo Scientific ISQ EC - Mass Spectrometer; Column: Kinetex ® 2.6 pm XB C18 (4.6x50mm), I lOA, mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in acetonitrile; Gradient conditions are reported in Table 12. Table 12: Method 10 conditions

[0281] Column temperature: 25 °C; UV detection: from 190 nm to 340 nm; MS conditions: Ionisation Mode: alternate-scan Positive and Negative Electrospray (ES+ / ES-), Scan Range: 100 to 1000 AMU.

[0282] Chiral Supercritical Fluid Chromatography (SFC) separation protocol

[0283] 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). 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 VI 0 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).

[0284] Preparative chiral separations

[0285] Method Chiral-Prep-1: SFC-MS was performed on a Sepiatech PreplOO SFC System, using a Lux C2 (20mm x 250mm, 5 pm) column with an isocratic run (ACN:CCh = 60:40), Flow Rate 50 mL / min, BPR 125 BarG, Detector Wavelength 231 nm, Injection Volume 1000 um (31 mg), 40°C column temperature.

[0286] Method Chiral-Prep-2: SFC-MS was performed on a Sepiatech PreplOO SFC System, using a CHIRALPAK® IG (20mm x 250mm, 5 pm) column with an isocratic run (ACN:CCh = 50:50 30:70), Flow Rate 50 mL / min, BPR 125 BarG, Detector Wavelength 231 nm, Injection Volume 400 um (20 mg), elution time 12 min., 40°C column temperature.

[0287] Method Chiral-Prep-3: SFC was performed on Novasep SUPERSEP 400, 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.

[0288] Chiral analytical methods Method Chiral-QC-1: SFC-MS was performed on a Waters Acquity UPC2 SFC System using a Lux C2 (4.6mm x 250mm, 5 pm) column with an isocratic run (ACN:CCh = 60:40), Flow Rate 4 mL / min, Detector Wavelength 210-400 nm, Injection Volume 1 pL, 40°C column temperature.

[0289] Method Chiral-QC-2: SFC-MS was performed on a Waters Acquity UPC2 SFC System using a CHIRALPAK® IG column (4.6mm x 250mm, 5 pm) column with an isocratic run (ACN:CO2 = 50:50), Flow Rate 4 mL / min, Detector Wavelength 210-400 nm, Injection Volume 1 pL, 40°C column temperature.

[0290] Method Chiral-QC-3

[0291] LC was performed on HPLC Agilent 1100 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.

[0292] PREPARATION OF INTERMEDIATES:

[0293] Intermediates Va and Vb: 1steluted diastereoisomer and 2ndeluted diastereoisomer of 3-(4-bromophenyl)tetrahydrofuran-3-carbonitrile.

[0294] A racemic mixture of 3-(4-bromophenyl)tetrahydrofuran-3-carbonitrile, Intermediate (V), prepared according to WO 2017156165) (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.

[0295] 1steluted diastereoisomer (Intermediate Va): 77.9 g, 49% yield.

[0296] 2ndeluted diastereoisomer (Intermediate Vb): 78.2 g, 49% yield.

[0297] Analytical data are reported in Table 13.

[0298] Table 13: Intermediates V analytical data

[0299] Intermediate Via: ethyl 2-(4-(3-cyanotetrahydrofuran-3-yl)phenyl)acetate

[0300] Step 1: brom o-(2-elhox\>-2-oxo-elh\>l) zinc

[0301] A mixture of the zinc granular, 30-100 mesh (40.0 g, 612 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.

[0302] Step 2: ethyl 2-(4-(3-cvanotetrahvdrofuran-3-yl)phenyl)acetate

[0303] A solution of enantiopure 3 -(4-bromophenyl)tetrahydrofuran-3 -carbonitrile (Intermediate Va) (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, 11.90 mmol), followed by Pd2(dba)3 (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 cyclohexane) 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, yield 79 %).

[0304] LC-MS Method 5: tR 1.00 min, MS ESI (+) m / z = 260.02 [M+H]+.

[0305] '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).

[0306] Intermediate VI-3: ethyl 2-(4-(l-cyanocyclopentyl)phenyl)acetate

[0307] A solution of c.a. l-(4-bromophenyl)cyclopentane-l -carbonitrile (1276 mg, 5.10 mmol), Allyl(chloro)palladium dimer (93 mg, 0.2 mmol), DMAP (62.3 mg, 0.5 mmol), BINAP (318 mg, 0.5 mmol) in Xylene (20 mL) was stirred at rt for 30 min. Then ethyl potassium malonate (1736 mg, 10.2 mmol) was added. The reaction mixture was stirred at 140 °C, then allowed to cool to RT and extraction with ethyl acetate was done, and the solvents were removed under reduce pressure. Crude material was purified by FCC (hexane: ethyl acetate = 9: 1) to give title compound (708 mg, 2.1 mmol, 40 %).

[0308] ‘HNMR (300 MHz, DMSO-d6) 5 7.49 - 7.42 (m, 2H), 7.36 - 7.28 (m, 2H), 4.09 (q, J = 7.1 Hz, 2H), 3.68 (s, 2H), 2.44 - 2.35 (m, 2H), 2.15 - 2.01 (m, 2H), 1.95 - 1.83 (m, 4H), 1.19 (t, J = 7.1 Hz, 3H).

[0309] The following Intermediate was prepared by a procedure similar to the one described above, using the suitable starting material (see Table 14).

[0310] Table 14: Intermediates VI analytical data Intermediate VI-alk-3: ethyl 2-(4-(l-cyanocyclopentyl)phenyl)-3-methylbutanoate

[0311] (VI-alk-3)

[0312] To a solution of ethyl 2-(4-(l-cyanocyclopentyl)phenyl)acetate (Intermediate (VI-3), 600 mg, 2.3 mmol) in DMF (5 mL) was added LiHMDS (2.78 mL, 2.8 mmol) at 0°C under Argon atmosphere. The reaction mixture was stirred for 30 min. then 2-iodopropane (0.256 mL, 2.56 mmol) was added. The reaction mixture was stirred at RT for 3 hrs, then it was poured into cool water and extracted with DCM. Solvents were removed under reduce pressure. Crude material was purified by FCC (hexane: ethyl acetate 4: 1) to give title compound (397 mg, 1.3 mmol, 57% yield) ‘HNMR (300 MHz, DMSO-d6) 5 7.50 - 7.44 (m, 2H), 7.40 - 7.34 (m, 2H), 4.16 - 3.94 (m, 2H), 3.25 (d, J = 10.4 Hz, 1H), 2.44 - 2.35 (m, 2H), 2.28 - 2.19 (m, 1H), 2.11 - 1.99 (m, 2H), 1.93 - 1.83 (m, 4H), 1.15 (t, J = 7.1 Hz, 3H), 0.98 (d, J = 6.5 Hz, 3H), 0.64 (d, J = 6.7 Hz, 3H).

[0313] The following Intermediates were prepared by procedures similar to the one described above, using the suitable starting material (see Table 15).

[0314] Table 15: Intermediates preparation and analytical data

[0315] Intermediate VII-3: ethyl 2-(4-(l-carbamoylcyclopentyl)phenyl)-3-methylbutanoate

[0316] 1807099

[0317] (vn-3) A ethyl 2-(4-(l-cyanocyclopentyl)phenyl)-3 -methylbutanoate, Intermediate (VI-3) (397 mg,

[0318] 1.3 mmol) was dissolved in DMSO (8 mL) then potassium carbonate (73.3 mg, 0.5 mmol) and 30 % wt hydrogen peroxide (1.08 mL, 10.6 mmol) were added. The reaction mixture was heated at 60°C and stirred on. Reaction mixture was allowed to cool to RT, water was added, then the precipitated solid was filtrated, washed with water and dried. Crude product was used directly to the next step without further purification. 'H NMR (300 MHz, DMSO-d6) 5 ppm 7.30 (d, J = 8.3 Hz, 2H), 7.23 (d, J = 8.1 Hz, 2H), 7.04 (s, 1H), 6.79 (s, 1H), 4.09 (dq, J = 11.2, 7.3 Hz, 1H), 3.97 (dt, J = 10.8, 7.0 Hz, 1H), 3.17 (d, J = 10.5 Hz, 1H), 2.25 - 2.13 (m, 1H), 1.78 - 1.65 (m, 2H), 1.59 (d, J = 5.9 Hz, 4H), 1.14 (t, J = 7.1 Hz, 3H), 0.96 (d, J = 6.5 Hz, 3H), 0.63 (d, J = 6.6 Hz, 3H). Two protons are hidden under DMSO signal. The following Intermediates were prepared by adaptations of the above procedure, using the suitable starting material (see Table 16).

[0319] Table 16: Intermediates preparation and analytical data

[0320] Intermediate IV-3: ethyl 2-(4-(l-aminocyclopentyl)phenyl)-3-methylbutanoate

[0321] (IV-3) To a solution of ethyl 2-(4-(l -carbarn oylcy cl opentyl)phenyl)-3-methylbutanoate, Intermediate (VII-3) (264 mg, 0.8 mmol)) in ACN (5 mL) and Water (1.0 mL)) was added BTIB (429 mg, 1 mmol). The reaction mixture was stirred at RT on. Water was added and extraction with DCM was done. Organic solvents were removed in vacuo. Crude material was purified by FCC (silica, DCM:MeOH 9: 1) to afford 294 mg of pure product to afford title compound (294 mg, 0.8 mmol, 98 % yield).

[0322] 'HNMR (300 MHz, Chloroform-d) 5 7.42 (d, J = 8.2 Hz, 2H), 7.33 (d, J = 8.2 Hz, 2H), 7.28 (s, 1H), 4.23 - 3.94 (m, 3H), 3.15 (d, J = 10.5 Hz, 1H), 2.36 - 2.19 (m, 2H), 2.19 - 2.04 (m, 2H), 2.04 - 1.87 (m, 2H), 1.87 - 1.69 (m, 2H), 1.23 (t, J = 7.1 Hz, 3H), 1.04 (d, J = 6.4 Hz, 3H), 0.70 (d, J = 6.6 Hz, 3H).

[0323] The following Intermediates were prepared by adaptations of the above procedure, using the suitable starting material (see Table 17).

[0324] Table 17: Intermediates preparation and analytical data

[0325] Intermediate IX: tert-butyl (5)-(l-(4-bromophenyl)-2-hydroxyethyl)carbamate

[0326] To a solution of c. a. (5)-2-amino-2-(4-bromophenyl)ethan-l-ol (CAS 354153-65-4, eNovation Chemicals LLC) (10.0 g, 46.3 mmol) in dry DCM (70 mL) and EtOH (5 mL), triethylamine (12.9 mL, 92.6 mmol) was added. The reaction mixture was cooled to 0 °C and solution of BOC2O (11.11 g, 50.91 mmol) in dry DCM (30 ml) was added dropwise. The reaction mixture was stirred at 0 °C for 1 h, then allowed to reach RT and stirred for additional 3 h. The reaction mixture was diluted with DCM (100 ml) and organic layer was washed with saturated aqueous NaHCCh (2x70 mL) and brine (2x70 mL), then dried over anhydrous Na2SO4 and evaporated to give the title compound as white solid (14.723 g, 44.2 mmol, yield: 96 %).

[0327] LC-MS Method 5: tR 1.05 min, MS ESI (+) m / z = 260.03 / 262.01 [M-56+H]+.

[0328] Intermediate X: tert-butyl (S)-4-(4-bromophenyl)-2,2-dimethyloxazolidine-3- carboxylate

[0329] To the solution of tert-butyl N-[(lS)-l-(4-bromophenyl)-2-hydroxy-ethyl]carbamate (IX) (17.7 g, 56.0 mmol) in acetone (300 mL), p-toluenesulfonic acid monohydrate (1065 mg, 5.6 mmol) and 2,2-dimethoxy propane (68.59 mL, 279.9 mmol) were added. The reaction mixture was stirred at RT overnight. The reaction mixture was concentrated to a smaller volume, then 250 mL of EtOAc was added and resulting mixture washed with saturated aqueous NaHCCh (2x50 mL) and brine (3x50 mL), then dried over anhydrous Na2SO4and evaporated to give the title compound as yellow solid (19.76 g, 55.5 mmol, yield: 99 %).

[0330] LC-MS Method 5: tR 1.42 min, MS ESI (+) m / z = 299.93 / 301.93 [M-56+H]+.

[0331] Intermediate XI: tert-butyl (S)-4-(4-(2-ethoxy-2-oxoethyl)phenyl)-2,2- dimethyloxazolidine-3-carboxylate

[0332] Step J: Synthesis of Reformatsky reagent bromo-(2-ethoxy-2-oxo-ethyl)zinc'.

[0333] A mixture of the zinc granular, 30-100 mesh (20.0 g, 306.0 mmol) in anhydrous 2-MeTHF (125 mL), under N2, was warmed to 30 °C. At that temperature ethyl 2-bromoacetate (1.25 g, 0.83 mL, 7.5 mmol), followed by DIBAL-H, IM in toluene (2.99 mL, 3.0 mmol) were added to the reaction mixture. The suspension was heated to 40 °C and then ethyl 2-bromoacetate (25 g, 16.6 mL, 150.0 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.

[0334] Step 2: Negishi coupling.

[0335] A solution of tert-butyl (4S)-4-(4-bromophenyl)-2,2-dimethyl-oxazolidine-3-carboxylate (X) (13.6 g, 38.2 mmol) in 2-MeTHF (100 mL) was purged with N2 for 20 min. The purging of the reaction with N2 was continued and then XPhos (3.64 g, 7.6 mmol), followed by Pd2(dba)s (3.50 g, 3.8 mmol) were added. The reaction mixture was heated to 60 °C and then freshly prepared solution of bromo-(2-ethoxy-2-oxo-ethyl)zinc, 1.05 M in 2-MeTHF (90.9 mL, 95.4 mmol) was added dropwise at 60°C over 2 h. The reaction mixture was stirred at 60°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 200 mL of EtOAc. The layers were separated, and the organic layer was washed with brine (2 x 100 mL) and concentrated in vacuo to give the crude product (20.62 g) as purple oily residue. The crude product was purified by flash chromatography on a Si cartridge (gradient elution 0-8 % EtOAc in cyclohexane). Fractions with pure product were combined and evaporated under reduced pressure to yield the title compound as brown oil (8.16 g, 22.2 mmol, yield: 58 %).

[0336] LC-MS Method 5: tR 1.33 min, MS ESI (+) m / z = 308.15 [M-56+H]+.

[0337] Intermediate XII-5: tert-butyl (4S)-4-(4-(l-ethoxy-3-methyl-l-oxobutan-2-yl)phenyl)- 2,2-dimethyloxazolidine-3-carboxylate

[0338] (xn-5)

[0339] Title compound was prepared by adapting procedure applied for the preparation of Intermediate (VI-alk-3), starting from tert-butyl (4S)-4-[4-(2-ethoxy-2-oxo-ethyl)phenyl]-2,2- dimethyl-oxazolidine-3-carboxylate (XI) (200 mg, 0.5 mmol) and 2-iodopropane (140 mg, 0.8 mmol), the title compound was obtained (220 mg, quantitative yield).

[0340] LC-MS (ESI, m / z): method 4, tR = 1.53 min, m / z (M-Boc+1) = 306.13

[0341] Intermediate IV-5: ethyl 2-(4-((S)-l-amino-2-hydroxyethyl)phenyl)-3- methylbutanoate hydrochloride

[0342] (IV-5)

[0343] Tert-butyl (4S)-4-[4-(l-ethoxycarbonyl-2-methyl-propyl)phenyl]-2,2-dimethyl- oxazolidine-3 -carboxylate (XII-5) (270 mg, 0.6 mmol) was dissolved in 4 MHCl / dioxane solution (2 mL). The reaction mixture was stirred at RT for 18 h. The reaction mixture was concentrated in vacuo to give title compound (204 mg, 0.6 mmol, yield 97%).

[0344] LC-MS (ESI, m / z): method 4, tR = 0.92 min, m / z (M+l) = 266.12

[0345] Intermediate IV-7: 4-methylthieno[2,3-b]indole-2-carboxylic acid

[0346] (IV-7)

[0347] To a solution of methyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)-3- methylbutanoate (III-alk-7) (115 mg, 0.3 mmol) in DCM (2 mL),nTFA (0.274 mL, 3.6 mmol) was added. The reaction mixture was left stirring at RT for 2 h. NaOH (I M, aq) was added until pH 8 was reached, then brine was added and the product was extracted with DCM. The combined organic phase was dried over phase separator and the solvent was evaporated affording title compound (66 mg, 0.27 mmol, yield 75 %).

[0348] LC-MS (ESI, m / z): method 4, tR = 0.95 min, m / z (M+l) = 221.97.

[0349] Intermediate XV-16: methyl 8H-thieno[2,3-b]indole-2-carboxylate

[0350] A mixture of c.a. tert-butyl 2-chloro-3-formyl-indole-l -carboxylate (348 mg, 1.2 mmol), dipotassium carbonate (189 mg, 1.4 mmol) and methyl 2-sulfanylacetate (130.9 pL, 1.4 mmol) in methanol (5 mL) was heated up to reflux and stirred on. Reaction mixture was allowed to cool to RT and poured into water. Resulting precipitate was collected by filtration, washed with water and dried affording title compound (232 mg, 1.0 mmol, 81 % yield).

[0351] LC-MS (ESI, m / z): method 5, tR = 1.08 min, m / z (M+l) = 232.14

[0352] Intermediate XVI-16: methyl 8-(2-(4-methylpiperazin-l-yl)ethyl)-8H-thieno[2,3- b] indole-2-carboxylate

[0353] (XVI-16)

[0354] A solution of methyl 4H-thieno[2,3-b]indole-2-carboxylate (115 mg, 0.5 mmol) in dry toluene (5.5 mL) was bubbled with argon. 2-(4-methylpiperazin-l-yl)ethanol (143 pL, 0.99 mmol) and 2-(tributyl-lambda5-phosphanylidene)acetonitrile (261 pL, 0.99 mmol) were added, vial was sealed. Reaction mixture was heated up to 80 °C and stirred for 4 h. Reaction mixture was concentrated in vacuo, obtained residue was purified by FCC DCM) / (DCM:MeOH = 20:1) gradient (0 - 50 % DCM:MeOH= 20:1) to afford title compound (89 mg, 0.25 mmol, 50 % yield). LC-MS (ESI, m / z): method 5, tR = 0.80 min, m / z (M+l) =358.21.

[0355] Intermediate XVII-16: 8-(2-(4-methylpiperazin-l-yl)ethyl)-8 / / -thieno|2.3- / ?|indole-2- carboxylic acid

[0356] (XVII- 16)

[0357] Methyl 4-[2-(4-methylpiperazin-l-yl)ethyl]thieno[2,3-b]indole-2-carboxylate (88 mg, 0.2 mmol) was dissolved in a mixture of THF (1.8 mL) and H2O (1.8 mL). Lithium hydroxide (17.7 mg, 0.7 mmol) was added and reaction mixture was stirred at RT for 72 h. THF was evaporated in vacuo, residue was diluted with water and pH of solution was adjust with 1 M HC1 to pH 6. Flask was cooled with ice bath until precipitate was formed. Precipitate was collected by filtration and dried in vacuum oven affording title compound (68 mg, 0.2 mmol, yield 80 %). LC-MS (ESI, m / z): method 5, tR = 0.67 min, m / z (M+l) = 344.16

[0358] PREPARATION OF EXAMPLES

[0359] Example 1 : (R)-4-(l-(8-methyl-8H-thieno [2,3-b] indole-2-carboxamido)ethyl)benzoic acid

[0360] To c.a. 8-methyl-8H-thieno[2,3-b]indole-2-carboxylic acid (75 mg, 0.3 mmol) in anhydrous DMF (0.7 mL) a solution of HATU (0.37M) / TEA (0.5M) in anhydrous DMF (1315 pl, 0.5 mmol) was added. Reaction mixture was stirred for 15 min and c.a. methyl (R)-4-(l-aminoethyl)benzoate in anhydrous DMF (695 pl, 0.4 mmol) was added. Reaction mixture was then stirred at RT on, then it was diluited with water, residual precipitate was centrifugated and washed with water twice. Crude was dissolved in Methanol (3243 pl) and IM NaOH (3243 pl, 3.2 mmol) was added and reaction mixture stirred at RT till completion, then it was concentrated and diluited with water. Then IM wt HC1 was added till pH=3 / 4 and precipitate was centrifugated, washed with water and dryed. Title compound was obtained (40 mg, 0.105 mmol, 32 % yield) as purple solid.

[0361] LC-MS (ESI, m / z): method 1, tR = 3.05 min, m / z (M+l) = 378.96

[0362] 'HNMR (400 MHz, DMSO-de) 5 ppm 12.85 (s, 1H), 8.88 (d, J = 7.9 Hz, 1H), 8.35 (s, 1H), 7.95 - 7.88 (m, 2H), 7.82 (dt, J = 7.8, 1.0 Hz, 1H), 7.59 (d, J = 8.2 Hz, 1H), 7.56 - 7.49 (m, 2H), 7.32 (ddd, J = 8.4, 7.2, 1.2 Hz, 1H), 7.21 (td, J = 7.5, 1.0 Hz, 1H), 5.19 (p, J = 7.1 Hz, 1H), 3.88 (s, 3H), 1.51 (d, J = 7.1 Hz, 3H).

[0363] Example 1-2: methyl (4-((R)-l-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)ethyl)benzoyl)-L-prolinate

[0364] (R)-4-(l-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)ethyl)benzoic acid (Example 1) (15 mg, 0.04 mmol) and c.a. methyl L-prolinate hydrochloride (7.88 mg, 0.1 mmol) was dissolved in Tetrahydrofuran (396 pl). TEA (22.10 pl, 0.159 mmol) and HATU (22.61 mg, 0.059 mmol) were added and reaction mixture was stirred at RT for 3 hrs. The reaction mixture was diluited with water, residual precipitate was centrifugated and washed with water twice to give title compound in quantitiative yield, which was used as it is in the next step.

[0365] LC-MS (ESI): Method 2, tR = 1.62 min; m / z (M+l) = 490.5 Example 1-3: ethyl 3-methyl-2-(4-(l-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)cyclopentyl)phenyl)butanoate

[0366] (1-3)

[0367] In a microwave vial were put c.a. 8-methyl-8H-thieno[2,3-b]indole-2-carboxylic acid (40 mg, 0.17 mmol), ethyl 2-(4-(l-aminocyclopentyl)phenyl)-3-methylbutanoate (IV-3) (55.1 mg, 0.190 mmol), HATU (99 mg, 0.3 mmol) and TEA (0.048 ml, 0.346 mmol. The reaction mixture was stirred at RT. Extraction with DCM was done. Organic solvents were removed under reduce pressure. Crude material was purified by preparative-TLC (Hex:AcOEt - 4:1) to give title compound (35 mg, 40%). LC-MS (ESI, m / z): method 2, tR = 2.22 min, m / z (M+Na+) = 525.5

[0368] The following Examples in Table 18 were prepared by adaptations of the above procedure, using the suitable amine and acid.

[0369] Table 18: Examples preparation and analytical data

[0370] Example 2: (4-((l?)-l-(8-methyl-8H-thieno[2,3-6]indole-2-carboxamido)ethyl)benzoyl)-

[0371] L-proline

[0372] To methyl (4-((R)-l-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)ethyl)benzoyl)-L- prolinate (Example 1-2, 19.41 mg, 0.04 mmol) in THF (396 pl), IM sodium hydroxide (396 pl, 0.4 mmol) was added and reaction mixture was stirred at RT for 72 h. Solvent was evaporated and crude dissolved in water. IM HC1 was added till pH=3 and precipitate was centrifugated. Water layer was separated and the solid washed twice with water and dried to give title compound (12 mg, 0.025 mmol, 64% yield) as purple solid.

[0373] LC-MS (ESI): method 1, tR = 2.83 min; m / z (M+l) = 475.9

[0374] ‘H NMR (300 MHz, DMSO-d6) 5 ppm 12.50 (s, 1H), 8.87 (d, J = 8.1 Hz, 1H), 8.35 (s, 1H), 7.82 (d, J = 7.7 Hz, 1H), 7.59 (d, J = 8.2 Hz, 1H), 7.54 - 7.38 (m, 4H), 7.36 - 7.28 (m, 1H), 7.21

[0375] (t, J = 7.5 Hz, 1H), 5.18 (t, J = 7.3 Hz, 1H), 4.37 (d, J = 5.7 Hz, 1H), 3.88 (s, 3H), 3.65 - 3.44 (m, 3H), 1.91 - 1.82 (m, 2H), 1.76 (t, J = 4.7 Hz, 1H), 1.51 (d, J = 7.0 Hz, 3H).

[0376] The following Examples in Table 19 were prepared by adaptations (e.g. including trituration steps of final material ) of the above procedure. Table 19: Examples preparation and analytical data

[0377] Intermediate XVIII-4: allyl 3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoate.

[0378] (XVIII-4) To a mixture of Example 4 (1.97 g, 4.1 mmol) and disodium carbonate (876 mg, 8.3 mmol) in DMF (10 mL), 3 -bromoprop- 1-ene (0.715 mL, 8.3 mmol) was added in one portion and the reaction mixture was stirred at RT for 4 h. Reaction mixture was partitioned between ethyl acetate and brine. Organic phase was washed with NH4CI, NaHCOs and brine, dried over Na2SO4 and concentrated in vacuo. The crude was triturated in diethyl ether, filtered off and dried over vacuo to provide title compound (2.02 g, 3.9 mmol, yield 95 %).

[0379] LC-MS (ESI): Method 6, tR = 5.47 min, m / z (M+l) =517.15

[0380] Intermediates XVIII-11, XVIII-12, XVIII-13, XVIII-14: allyl 3-methyl-2-(4-(3-(8- methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran-3-yl)phenyl)butanoate single stereoisomers.

[0381] A racemic mixture of allyl 3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoate; Intermediate (XVIII-4), was subject to two subsequent preparative chiral SFCs to give the single stereoisomers (See Scheme 8)

[0382] Scheme 8

[0383] Intermediate XVIII-13 (3rdeluted stereoisomer) and Intermediate XVIII-14 (4theluted stereoisomer). Order of elution according to Method SFC-QC-1.

[0384] A racemic mixture of allyl 3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoate, Intermediate (XVIII-4), 2.02 g, 3.9 mmol) was dissolved to 31 mg / mL in MeCN and was separated by Method Chiral -Prep- 1, to give the desired products.

[0385] Mixture of 1stand 2ndeluted stereoisomers

[0386] 3rdeluted stereoisomer (Intermediate XVIII-13): 486 mg

[0387] 4theluted stereoisomer (Intermediate XVIII-14): 484 mg Intermediate XVIII-12 (1steluted stereoisomer) and Intermediate XVIII-11 (2ndeluted stereoisomer) Order of elution according to Method SFC-QC-1.

[0388] The mixture of 1stand 2ndeluted stereoisomers was dissolved to 50 mg / mL in MeCN and was separated by preparative SFC, using Method Chiral-Prep-2 (in this method and in Method SFC- QC-2 order of elution of XVIII-11 and XVIII-12 is reversed), to give the desired products. Order of elution below is according to Method SFC-QC-1.

[0389] 1steluted stereoisomer (Intermediate XVIII-12): 461 mg

[0390] 2ndeluted stereoisomer (Intermediate XVIII-11): 467 mg

[0391] Table 20: Intermediates XVIII analytical data Example 11: 3-methyl-2-(4-(3-(8-methyl-8H-thieno [2,3-6] indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoic acid

[0392] 11

[0393] Intermediate (XVIII-11) (40.0 mg, 0.0774 mmol) was dissolved in anhydrous THF (2.0 mL) and bubbled with Argon. In Ar atmosphere at rt Pd(PPh3)4 (8.95 mg, 0.008 mmol) was added, followed by morpholine (6.77 pL, 0.08 mmol). The reaction mixture was stirred at 40°C for 1 h. The reaction mixture was cooled to RT, diluted with water and acidified with IM HC1 solution until pH < 2. Resulting product was extracted with EtOAc. Organic layers were combined, filtered through celite and filtrate was evaporated in vacuo. Obtained residue was dissolved in anhydrous THF (5.00 mL) and SiliaMetS DMT (37.9 mg, molecular loading 0.5 mmol / g) was added. The mixture was stirred at rt for 17 h, then filtered off and the filtrate was evaporated in vacuo affording crude material. Crude was purified by FCC eluting with DCM / MeOH gradient (0-3 % MeOH).

[0394] Fractions with desired product were evaporated to dryness, affording title product (18 mg, 0.04 mmol, 49.5 %).

[0395] LC-MS (ESI, m / z): method 7, tR = 6.58 min, m / z (M-l) = 477.18 'H NMR (600 MHz, DMSO-d6) 5 ppm 12.30 (br s, 1H), 8.86 (s, 1H), 8.41 (s, 1H), 7.83 (d, J = 7.6 Hz, 1H), 7.59 (d, J = 8.2 Hz, 1H), 7.36 (d, J = 8.4 Hz, 2H), 7.34 - 7.30 (m, 1H), 7.25 (d, J =

[0396] 8.4 Hz, 2H), 7.23 - 7.19 (m, 1H), 4.26 (d, J= 9.0 Hz, 1H), 4.09 (d, J= 9.0 Hz, 1H), 3.96 - 3.92 (m, 2H), 3.87 (s, 3H), 3.05 (d, J= 10.3 Hz, 1H), 2.81 - 2.74 (m, 1H), 2.34 - 2.27 (m, 1H), 2.21 - 2.14 (m, 1H), 0.98 (d, J= 6.4 Hz, 3H), 0.62 (d, J= 6.4 Hz, 3H).

[0397] The following Examples in Table 21 were prepared by according to the above procedure, starting from the suitable Intermediate.

[0398] Table 21: Examples preparation and analytical data

[0399] PHARMACOLOGICAL ACTIVITY OF THE COMPOUNDS OF THE INVENTION 3-Phosphoglycerate Dehydrogenase (PHGDH) Biochemical Assay

[0400] This enzymatic assay measures inhibitory activity of compounds of PHGDH enzyme, which catalyzes the reaction of 3 -phosphoglycerate and NAD+to 3-phosphohydroxypyruvate and NADH. The NADH, produced by the reaction, is used in a coupled reaction of reduction resazurin to resorufin by diaphorase; the resorufin is measured in a fluorescence intensity readout. The assay was performed using commercially available recombinant Human PHGDH, full length, C- terminal His-tag (BPS Biosciences 71079). The assay was adapted for two different NAD+final assay concentrations: low NAD: 4 pM, high NAD: 250 pM. Two mixes were prepared before running the protocol: Mix 1 : with PHGDH (final assay concentration 0.008 pg / ml) and NAD+(final assay concentration 4 pM or 250 pM) in the assay buffer (Tris 41.7 mM HC1, pH 7.5, 18.7 mM hydrazine sulfate pH 9, 0.8 mM EDTA, 0.004% Tween20) and Mix 2: with 0.17 mM PGA, 0.02 mM resazurin and 0.66 U / mL diaphorase in H2O.

[0401] Briefly, the enzymatic reaction was performed by incubating each concentration of compounds with MIX 1 at 25 °C. After an incubation of 60 min, the MIX 2 was added and further incubated at 25°C for 180 min. After the incubation, the fluorescence intensity was read (Excitation @ X 554 nm / Emission @ X 593 nm). The assays were performed in 384-well format and validated using a selected reference compound, tested in 10-point concentration-response curve. All compounds were tested in 10-point concentration-response curve, 3-fold dilutions, each in duplicate. The following controls were included in each assay plate: high control - DMSO vehicle control (1% final reaction volume) and low control - maximal inhibition control (3 pM reference inhibitor). Raw data were processed to obtain dose response curves for the compounds: Fluorescence data are normalized to high control and low control and IC50 values were determined in automated script for dose-response analysis, using 4 parameter model: log(inhibitor) vs. response. Results were expressed as IC50 value, given in nM for each NCE or pICso (negative logarithm of ICso). QC criteria parameters: Z' > 0.5, Hill Slope range 0.5 to 5, S:B > 2.

[0402] Test compound potencies in High NAD+are reported in Table 22 as pIC50 values.

[0403] Table 22: pICso values in High NAD+concentration assay wherein the compounds are classified in term of potency with respect to their inhibitory activity on PHGDH enzyme according to the following classification criterion:

[0404] +: pICso comprised between 5.5 and 6.0

[0405] ++: pICso comprised between 6.0 and 7.0

[0406] +++: pICso higher than 7.0

[0407] As it can be appreciated, all the compounds of Table 22 show an inhibitory activity on PHGDH enzyme. In fact, it can be recognized that the symbol + indicate a sufficient or good level of activity, which can be even increased up to +++, thus confirming the high activity on PHGDH enzyme of the compounds of the invention. Compounds according to the invention showed PHGDH inhibitory activity higher than 5.5 pICso (high NAD+conditions assay), corresponding to < 3 pM in terms of inhibitory concentration. Most preferably, compounds showed values higher than 6.0, and even more preferably higher than 7.0, corresponding to < 1 pM, even more preferably < 0.1 pM, in terms of inhibitory concentration.

[0408] 13C3- Serine flux Assay in MDA-MB-468 Cells

[0409] This method describes a cellular serine flux assay based on13C3-Serine MS read out to profile PHGDH inhibitors. PHGDH is a key enzyme for Serine biosynthesis, and it is described that breast cancer cells (MDA-MB468) can be dependent on PHGDH for their growth and survival. Two different media, without glycine and serine, were used for the Serine flux assay in the cell plates:

[0410] 1) starting medium: modified RPMI 1640 (Teknova R9660) supplemented with AA powder, P / S, 5 mM / .-Glutamine, 10% FBS dialyzed, 2 g / L D-(+)-glucose.

[0411] 2) assay medium: modified RPMI 1640 supplemented with AA powder, P / S, 5 mM L- Glutamine, 10% dialyzed FBS, 2 g / L13Ce-glucose, instead of unlabelled £>-(+)-Glucose.

[0412] On assay day 0, MDA-MB-468 cells were seeded at a density of 50.000 cells / well in 100 pL starving medium lacking Serine and Glycine and incubated for 20-24 hours. Day 1, cells were washed twice with assay medium containing13Ce-Glucose before addition of compound dilutions; compound solutions were prepared by a further dilution in DMSO from stock to 30 mM, Serial dilution 1 :3 in DMSO was performed in a compound-plate, to generate 8 points Concentration- Response-Curve (CRC), each point in triplicate.

[0413] Compound-plates were used immediately after preparation on the day of the experiment. The following controls were included in assay plate: basal control / no inhibition (DMSO, 8- replicates / plate); QC / maximal inhibition (reference compound, 30 pM final, 8-replicates / plate). Assay cell plates were then incubated at 37 °C, 5% CO2 for 24 hours, when the conditioned culture medium was used for13C3-Serine detection. On Day 2, 50 pL / well of the cell supernatant was collected and transferred into a sample-plate for LC-MS analysis. Raw data were processed to obtain dose response curves for the compounds: data were normalized to high control and low control and IC50 values were determined in automated script for dose-response analysis, using 4 parameter model: log(inhibitor) vs. response.

[0414] Results were expressed as IC50 value, given in nM for each NCE or pICso (negative logarithm of IC50). QC criteria parameters: Z' > 0.5, Hill Slope range 0.5 to 5, S:B > 2.

[0415] Test compound potencies in13C3- Serine flux Assay in MDA-MB-468 Cells are reported in Table 23 as pIC50 values. Table 23: pICso values in13C3- Serine flux Assay in MDA-MB-468 Cells assay wherein the compounds are classified in term of potency with respect to their inhibitory activity on13C3-Serine biosynthesis according to the following classification criterion:

[0416] +: pICso comprised between 5.5 and 6.0 ++: pICso comprised between 6.0 and 6.5

[0417] +++: pICso higher than 6.5.

[0418] As it can be appreciated, all the compounds of Table 23 show an inhibitory activity on PHGDH pathway. In fact, it can be recognized that the symbol + indicate a sufficient or good level of activity, which can be even increased up to +++, thus confirming the high activity on PHGDH pathway of the compounds of the invention.

[0419] Compounds according to the invention showed PHGDH cellular inhibitory activity higher than 5.5 pICso, corresponding to <3 pM in terms of inhibitory concentration. Most preferably, compounds showed values higher than 6.0, and even more preferably higher than 6.5, corresponding to < 1 pM, even more preferably < 0.3 pM, in terms of inhibitory concentration.

Claims

CLAIMS1. A compound of formula (I):whereinRi is -(Ci-Ce)alkyl, optionally substituted with -(C3-C7)heterocycloalkyl, wherein such -(C3-C7)heterocycloalkyl is optionally substituted with -(Ci-Ce)alkyl;R2 and R3 are independently H or -(Ci-Ce)alkyl, optionally substituted with -ORs, or R2 and Rj are fused together to form a -(C3-C6)cycloalkyl or -(C3- C7)heterocycloalkyl;R4 or R5 are independently H or -(Ci-Ce)alkyl;Li is a covalent bond or a -(CO)-NR2R3- group, or -(Ci-Ce)alkylene group optionally substituted with OR4, wherein when Li is -(CO)-NR2R3- and Rz and Rj are fused together in a -(C3- C7)heterocycloalkyl, the carboxyl group -(C0)-0-R4 of formula (I) is linked to anyone of the C atom of such -(C3-C7)heterocycloalkyl; and pharmaceutically acceptable salts thereof.

2. A compound of formula (I) according to claim 1 , wherein R4 is H, represented by the general formula (la)wherein Ri, R2, R3, Rs and Li are as defined in claim 1; and pharmaceutically acceptable salts thereof.

3. The compound of formula (I) or formula (la) according to claim 1 or 2, wherein:Ri is selected from methyl or ethyl, optionally substituted by methyl-piperazine.and pharmaceutically acceptable salts thereof.

4. The compound of formula (I) or formula (la) according to claim 1-3, wherein:Rz and R3 are independently H or methyl, optionally substituted by -OH, or are fused together in a tetrahydrofurane, cyclopentane or cyclobutane; and pharmaceutically acceptable salts thereof.

5. The compound according to any one of claims 1 to 3, selected from at least one of:(R)-4-(l-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)ethyl)benzoic acid; (4-((R)-l-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)ethyl)benzoyl)-L- proline;3-methyl-2-(4-(l-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)cyclopentyl)phenyl)butanoic acid;3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran- 3-yl)phenyl)butanoic acid;2-(4-((S)-2-hydroxy-l-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)ethyl)phenyl)-3 -methylbutanoic acid;2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran-3- yl)phenyl)acetic acid;3-methyl-2-(4-((8-methyl-8H-thieno[2,3-b]indole-2- carb oxami do)methy l)pheny l)butanoi c aci d;3-methyl-2-(4-(l-(8-methyl-8H-thieno[2,3-b]indole-2- carb oxami do)cy cl obuty l)pheny l)butanoi c aci d;(S)-2-(4-(2-hydroxy-l-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)ethyl)phenyl)acetic acid;4-methoxy-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoic acid;3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran- 3-yl)phenyl)butanoic acid;3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran- 3-yl)phenyl)butanoic acid;3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran- 3-yl)phenyl)butanoic acid;3-methyl-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2-carboxamido)tetrahydrofuran- 3-yl)phenyl)butanoic acid;4-methoxy-2-(4-(3-(8-methyl-8H-thieno[2,3-b]indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoic acid;3-methyl-2-(4-(3-(8-(2-(4-methylpiperazin-l-yl)ethyl)-8H-thieno[2,3-b]indole-2- carboxamido)tetrahydrofuran-3-yl)phenyl)butanoic acid; as single deuterate, enantiomer, diastereoisomer or mixtures thereof, in any proportion, or pharmaceutically acceptable salts and solvates thereof.

6. A compound of formula (I) according to claim 1, wherein Li is -(CO)-NR2R3-, represented by the general formula (Ic)wherein Ri, Rz, Rj, R and Rs are defined as above; and pharmaceutically acceptable salts thereof.

7. A compound of formula (I) according to claim 6, wherein Li is -(CO)-NR2R3-, represented by the general formula (Id)wherein Ri, R, R, R and Rs are defined as above; and pharmaceutically acceptable salts thereof.

8. A pharmaceutical composition comprising a compound according to any one of claims 1 to 7, in admixture with one or more pharmaceutically acceptable carrier or excipient.

9. A compound of formula (I) according to any one of claims 1-7 or a pharmaceutical composition according to claims 8 for use as a medicament.

10. A compound of formula (I) according to any one of claims 1-7 or a pharmaceutical composition according to claims 8 for use according to claim 9 in treating disease, disorder, or condition associated with dysregulation of 3 -phosphoglycerate dehydrogenase (PHGDH).

11. A compound of formula (I) according to claims 1 to 7 or a pharmaceutical composition according to claims 8 for use according to claim 9 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 9-13 for oral administration.

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