WO2021240423A1 - Dihydroorotate dehydrogenase inhibitors - Google Patents

Abstract

Disclosed are compounds, compositions and methods for treating diseases, disorders, or medical conditions that are affected by the modulation of DHODH. Such compounds are represented by Formula (I) as follows, wherein R¹, R², R³, R⁴, X, Y, and Z are defined herein.

Description

DIHYDROOROTATE DEHYDROGENASE INHIBITORS

CROSS REFERENCE TO RELATED APPLICATIONS This application is entitled to priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63/031,610, filed on May 29, 2020, the disclosure of which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to novel compounds that are dihydroorotate dehydrogenase (DHODH) inhibitors. These compounds may be useful for the treatment of a disease, disorder, or medical condition where there is an advantage in inhibiting DHODH. The invention also relates to pharmaceutical compositions comprising one or more of such compounds, to processes to prepare such compounds and compositions, and to the use of such compounds or pharmaceutical compositions for the method of treatment of cancer, and autoimmune and inflammatory diseases, syndromes, and disorders.

BACKGROUND OF THE INVENTION Acute myelogenous leukemia (AML) is a clonal disease of the blood and bone marrow resulting from mutations that occur in normal hematopoietic stem cells. AML is a heterogenous disease in that it presents with a range of cytogenetic, morphological and immunophenotypic features, and is characterized by an accumulation of clonal, abnormal myeloid progenitor cells, known as myeloblasts. These cells demonstrate disruption of normal myeloid differentiation and excessive proliferation, resulting in the decreased formation of hematopoietic cells. Disease remission can be achieved with standard induction chemotherapy, but refractory and relapsed disease remains a challenge due to persistence of leukemic stem cells. Therefore, AML represents an unmet medical need with >20,000 new cases per year in the US with 5-year overall survival below 30% (Stein ET et al, Health Qual Life Outcomes 16: 193, 2018).

Differentiation therapy is considered an attractive approach to AML treatment based on the knowledge that differentiation and loss of stem cell self-renewal are coupled in normal cells. Treatment of acute promyelocytic leukemia, which represents 10-15% of all AML, with all-trans retinoic acid is the paradigm for differentiation therapy. Retinoic acid targets the promyelocytic leukemia protein (PML)-retinoic acid receptor-a (RAR-a) fusion protein encoded by a t(l 5, 17) chromosomal translocation. Targeting PML-RAR specifically lifts the transcriptionally mediated differentiation block induced by the fusion protein and early clinical trials with single agent ATRA demonstrated complete hematologic remission in all treated patients (McCulloch D et al. Onco Targets Ther 2017; 10: 1585-1601; Nowak D et al. Blood 113: 3655, 2009).

Although differentiation therapy is successful, it is only applicable to a small population of AML patients. Research efforts have aimed at identifying additional differentiation inducing agents, but with limited success. Recently dihydroorotate dehydrogenase (DHODH) emerged as a potentially more broadly applicable differentiation target in a phenotypic screen aimed at identifying small molecules that overcome blockade of the maturation of primary murine bone marrow cells expressing the homeobox protein HoxA9. This protein is a key transcription factor involved in balancing stem cell maintenance/differentiation and is normally expressed in hematopoietic progenitor cells and downregulated upon induction of differentiation and has been found to be widely overexpressed in AML (Sykes et al, Cell 167: 171, 2016).

DHODH is a flavin mononucleotide (FMN) flavoprotein located in the inner mitochondrial membrane that catalyzes the oxidation of dihydroorotate to orotate, the fourth step in the de novo pyrimidine biosynthesis pathway. Inhibition of DHODH leads to decreased pyrimidine synthesis important precursors for nucleotide synthesis, but also glycoprotein and phospholipid biosynthesis (Reis RAG et al, Archives Biochem Biophysics 632: 175, 2017; Vyas VK et al, Mini Rev Med Chem 11: 1039, 2011).

DHODH is a validated target for the treatment of autoimmune diseases with the FDA approved small molecule DHODH inhibitors leflunomide and teriflunomide for rheumatoid arthritis and multiple sclerosis, respectively (Lolli ML et al., Recent patents on Anti-Cancer Drug Discovery 13: 86, 2018).

Since the first observation by Sykes et al. demonstrating that DHODH inhibition drives AML differentiation in vitro, as evidenced by upregulation of the differentiation markers CD11b and CD 14, and results in dose dependent anti-leukemic effects, decreased leukemic stem cells and prolonged survival in vivo, additional evidence emerged demonstrating that small molecule DHODH inhibitors mediate antiproliferative activity against AML cells with concomitant cell cycle arrest, upregulation of CD11b and CD 14, and induction of apoptosis (Wu D et al.. Haematologica 103: 1472, 2018; Sainas S et al., J Med Chem 61 : 6034, 2018; Cao L et al, Mol Cancer Ther, October 23rd Epub ahead of print). Moreover, preclinical solid tumor in vitro and in vivo models demonstrated effectiveness of DHODH inhibition and DHODH was identified as a synthetic lethality in PTEN and KRAS mutant solid tumors (Pharmacology and Therapeutics, Epub October 19th, 2018; Mathur D et al., Cancer Discovery 7: 1, 2017; Cell Chemical Biology 25: 1,

2018).

Thus, there remains a need for DHODH inhibitors that provide a therapeutic benefit to patients suffering from cancer and/or inflammatory and immunological diseases. SUMMARY OF THE INVENTION

Embodiments of the present invention relate to compounds, pharmaceutical compositions containing them, methods of making and purifying them, methods of using them as inhibitors of DHODH enzymatic activity and methods for using them in the treatment of a subject suffering from or diagnosed with a disease, disorder, or medical condition such as autoimmune or inflammatory disorders, or diseases such as cancer.

Embodiments of this invention are compounds of Formula (I),

wherein

X-Y-Z is selected from the group consisting of:

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

wherein

L is selected from the group consisting of: CH₂, NH, CH(CH₃), and C(=O);

R^c is halo or C_1-6alkyl; and

R^d is selected from the group consisting of: H, halo, and C_1-6alkyl; or a pharmaceutically acceptable salt, isotope, N-oxide, solvate, or stereoisomer thereof.

The present invention further provides methods for treating or ameliorating a disease, syndrome, condition, or disorder in a subject, including a mammal and/or human in which the disease, syndrome, condition, or disorder is affected by the inhibition of DHODH enzymatic activity, including but not limited to, cancer and/or inflammatory or immunological diseases, using a compound of Formula (I) or a pharmaceutically acceptable salt, isotope, N-oxide, solvate, or stereoisomer thereof.

Additional embodiments, features, and advantages of the invention will be apparent from the following detailed description and through practice of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in art. As used in the specification and the appended claims, unless specified to the contrary, the following terms have the meaning indicated in order to facilitate the understanding of the present invention.

The singular forms "a", "an" and "the" encompass plural references unless the context clearly indicates otherwise.

With reference to substituents, the term “independently” refers to the situation where when more than one substituent is possible, the substituents may be the same or different from each other.

The term “substituted” means that the specified group or moiety bears one or more substituents. The term "unsubstituted" means that the specified group bears no substituents. The term “optionally substituted” means that the specified group is unsubstituted or substituted by one or more substituents. Where the term “substituted” is used to describe a structural system, the substitution is meant to occur at any valency- allowed position on the system.

Unless qualified specifically in particular instances of use, the term “alkyl” refers to a straight- or branched-chain alkyl group having from 1 to 8 carbon atoms in the chain. Examples of alkyl groups include methyl (Me), ethyl (Et), n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl (tBu), pentyl, isopentyl, tert-pentyl, hexyl, isohexyl, and groups that in light of the ordinary skill in the art and the teachings provided herein would be considered equivalent to any one of the foregoing examples. “C_1-6alkyl” refers to straight- or branched-chain alkyl group having from 1 to 6 carbon atoms in the chain. “C_{1- 4}alkyl” refers to straight- or branched-chain alkyl group having from 1 to 4 carbon atoms in the chain.

The term “cycloalkyl” refers to a saturated or partially saturated, monocyclic, fused polycyclic, or spiro polycyclic carbocycle having from 3 to 12 ring atoms per carbocycle. “C_3-6cycloalkyl” refers to a carbocycle having from 3 to 6 ring atoms per carbocycle. Illustrative examples of cycloalkyl groups include the following entities, in the form of properly bonded moieties:

The term “halogen” or “halo” represents chlorine, fluorine, bromine, or iodine.

The term “haloalkyl” refers to a straight- or branched-chain alkyl group having from 1 to 6 carbon atoms in the chain optionally substituting hydrogens with halogens. The term “C_1-6 haloalkyl” as used here refers to a straight- or branched-chain alkyl group having from 1 to 6 carbon atoms in the chain, optionally substituting hydrogens with halogens. The term “C_1-4 haloalkyl” as used here refers to a straight- or branched-chain alkyl group having from 1 to 4 carbon atoms in the chain, optionally substituting hydrogens with halogens. Examples of “haloalkyl” groups include trifluoromethyl (CF₃), difluoromethyl (CF₂H), monofluoromethyl (CH₂F), pentafluoroethyl (CF₂CF₃), tetrafluoroethyl (CHFCF₃), monofluoroethyl (CH₂CH₂F), trifluoroethyl (CH₂CF₃), tetrafluorotrifluoromethylethyl (CF(CF₃)₂), and groups that in light of the ordinary skill in the art and the teachings provided herein would be considered equivalent to any one of the foregoing examples.

The term “aryl” refers to a monocyclic, aromatic carbocycle (ring structure having ring atoms that are all carbon) having 6 atoms per ring. (Carbon atoms in the aryl groups are sp2 hybridized.)

The term “phenyl” represents the following moiety:

The term “benzyl” represents the following moiety:

The term “heteroaryl” refers to a monocyclic or fused bicyclic heterocycle (ring structure having ring atoms selected from carbon atoms and up to four heteroatoms selected from nitrogen, oxygen, and sulfur) having from 3 to 9 ring atoms per heterocycle. Illustrative examples of heteroaryl groups include the following entities, in the form of properly bonded moieties:

Those skilled in the art will recognize that the species of cycloalkyl, heteroaryl and aryl groups listed or illustrated above are not exhaustive, and that additional species within the scope of these defined terms may also be selected.

The term “variable point of attachment” means that a group is allowed to be attached at more than one alternative position in a structure. The attachment will always replace a hydrogen atom on one of the ring atoms. In other words, all permutations of bonding are represented by the single diagram, as shown in the illustrations below.

Those skilled in the art will recognize that that if more than one such substituent is present for a given ring, the bonding of each substituent is independent of all of the others. The groups listed or illustrated above are not exhaustive.

As used herein, the term "or" means "and/or" unless stated otherwise. As used herein, the terms "including", "containing" and “comprising” are used in their open, non-limiting sense.

As used herein, the term "composition" is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts.

As used herein, the term “treat”, “treating”, or “treatment” of any disease, condition, syndrome or disorder refers, in one embodiment, to ameliorating the disease, condition, syndrome or disorder (i.e. slowing or arresting or reducing the development of the disease or at least one of the clinical symptoms thereof). In another embodiment, “treat”, “treating”, or “treatment” refers to alleviating or ameliorating at least one physiological or biochemical parameter associated with or causative of the disease, condition, syndrome or disorder, including those which may not be discernible by the patient. In a further embodiment, “treat”, “treating”, or “treatment” refers to modulating the disease, condition, syndrome or disorder either physically ( e.g . stabilization of a discernible symptom), physiologically, (e.g. stabilization of a physical parameter), or both. In yet another embodiment, “treat”, “treating”, or “treatment” refers to preventing or delaying the onset or development or progression of the disease, condition, syndrome or disorder.

The terms “subject” and “patient” are used interchangeably herein and may refer to an animal, preferably a mammal, most preferably a human.

As used herein, the terms active compound, pharmaceutical agent and active ingredient are used interchangeably to refer to a pharmaceutically active compound. Other ingredients in a drug composition, such as carriers, diluents or excipients, may be substantially or completely pharmaceutically inert. A pharmaceutical composition (also referred to herein as a composition or formulation) may comprise the active ingredient in combination with one or more carriers and/or one or more excipients and/or one or more diluents.

The term “therapeutically effective amount” (used interchangeably herein with “effective amount”) refers to an amount (e.g., of an active compound or pharmaceutical agent, such as a compound of the present invention), which elicits the biological or medicinal response in a tissue system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician, including reduction or inhibition of an enzyme or a protein activity, or ameliorating symptoms, alleviating conditions, slowing or delaying disease progression, or preventing a disease. Stated another way, the term therapeutically effective amount may refer to an amount that, when administered to a particular subject, achieves a therapeutic effect by inhibiting, alleviating or curing a disease, condition, syndrome or disorder in the subject or by prophylactically inhibiting, preventing or delaying the onset of a disease, condition, syndrome or disorder, or symptom(s) thereof. A therapeutically effective amount may be an amount which relieves to some extent one or more symptoms of a disease, condition, syndrome or disorder in a subject; and/or returns to normal either partially or completely one or more physiological or biochemical parameters associated with or causative of the disease, condition, syndrome or disorder; and/or reduces the likelihood of the onset of the disease, condition, syndrome or disorder, or symptom(s) thereof.

"Pharmaceutically acceptable" means that, which is useful in preparing a pharmaceutical composition that is generally safe, non-toxic and neither biologically nor otherwise undesirable and includes that which is acceptable for veterinary as well as human pharmaceutical use.

A "pharmaceutically acceptable salt” is intended to mean a salt of an acid or base of a compound represented by Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)) that is non-toxic, biologically tolerable, or otherwise biologically suitable for administration to the subject. See, generally, S.M. Berge, et ah, “Pharmaceutical Salts”, J. Pharm. Sci., 1977, 66:1-19, and Handbook of Pharmaceutical Salts, Properties, Selection, and Use, Stahl and Wermuth, Eds., Wiley-VCH and VHCA, Zurich, 2002. Preferred pharmaceutically acceptable salts are those that are pharmacologically effective and suitable for contact with the tissues of patients without undue toxicity, irritation, or allergic response.

Non-limiting examples of pharmaceutically acceptable salts include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, phosphates, monohydrogen-phosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caproates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-di oates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, sulfonates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, g-hydroxybutyrates, glycolates, tartrates, methane-sulfonates, propanesulfonates, naphthalene- 1 -sulfonates, naphthalene-2-sulfonates, and mandelates.

A compound of Formula (I) may possess a sufficiently acidic group, a sufficiently basic group, or both types of functional groups, and accordingly react with a number of inorganic or organic bases, and inorganic and organic acids, to form a pharmaceutically acceptable salt.

Compounds of Formula (I) may contain at least one nitrogen of basic character, so desired pharmaceutically acceptable salts may be prepared by any suitable method available in the art, for example, treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, sulfamic acid, nitric acid, boric acid, phosphoric acid, and the like, or with an organic acid, such as acetic acid, phenylacetic acid, propionic acid, stearic acid, lactic acid, ascorbic acid, maleic acid, hydroxymaleic acid, isethionic acid, succinic acid, valeric acid, fumaric acid, malonic acid, pyruvic acid, oxalic acid, glycolic acid, salicylic acid, oleic acid, palmitic acid, lauric acid, a pyranosidyl acid, such as glucuronic acid or galacturonic acid, an alpha-hydroxy acid, such as mandelic acid, citric acid, or tartaric acid, an amino acid, such as aspartic acid or glutamic acid, an aromatic acid, such as benzoic acid, 2-acetoxybenzoic acid, naphthoic acid, or cinnamic acid, a sulfonic acid, such as laurylsulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, any compatible mixture of acids such as those given as examples herein, and any other acid and mixture thereof that are regarded as equivalents.

Compounds of Formula (I) may contain a carboxylic acid moiety, a desired pharmaceutically acceptable salt may be prepared by any suitable method, for example, treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal hydroxide, alkaline earth metal hydroxide, any compatible mixture of bases such as those given as examples herein, and any other base and mixture thereof that are regarded as equivalents or acceptable substitutes in light of the ordinary level of skill in this technology. Illustrative examples of suitable salts include organic salts derived from amino acids, such as glycine and arginine, ammonia, carbonates, bicarbonates, primary, secondary, and tertiary amines, and cyclic amines, such as benzylamines, pyrrolidines, piperidine, morpholine, piperazine, N-methyl-glucamine and tromethamine and inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum, and lithium.

Each compound used herein may be discussed interchangeably with respect to its chemical formula, chemical name, abbreviation, etc.

Any formula given herein is intended to represent compounds having structures depicted by the structural formula as well as certain variations or forms. In particular, compounds of any formula given herein may have asymmetric centers and therefore exist in different enantiomeric forms. All optical isomers and stereoisomers of the compounds of the general formula, and mixtures thereof, are considered within the scope of such formula. The compounds of this invention may possess one or more asymmetric centers; such compounds can therefore be produced as individual ( R )- or (S )-stereoisomers or as mixtures thereof. Thus, any formula given herein is intended to represent a racemate, one or more of its enantiomeric forms, one or more of its diastereomeric forms, and mixtures thereof. Additionally, any formula given herein is intended to refer also to any one of: hydrates, solvates, polymorphs and of such compounds, and mixtures thereof, even if such forms are not listed explicitly.

The term “R” at a stereocenter designates that the stereocenter is purely of the R- configuration as defined in the art; likewise, the term “S” means that the stereocenter is purely of the S-configuration. As used herein, the term “RS” refers to a stereocenter that exists as a mixture of the R- and S-configurations .

Compounds containing one stereocenter drawn without a stereo bond designation are a mixture of 2 enantiomers. Compounds containing 2 stereocenters both drawn without stereo bond designations are a mixture of 4 diastereomers. Compounds with 2 stereocenters both labeled “RS” and drawn with stereo bond designations are a 2- component mixture with relative stereochemistry as drawn. Unlabeled stereocenters drawn without stereo bond designations are a mixture of the R- and S-configurations. For unlabeled stereocenters drawn with stereo bond designations, the absolute stereochemistry is as depicted.

Unless indicated otherwise, the description or naming of a particular compound in the specification and claims is intended to include both individual enantiomers and mixtures, racemic or otherwise, thereof. The methods for the determination of stereochemistry and the separation of stereoisomers are well-known in the art.

Reference to a compound herein stands for a reference to any one of: (a) the recited form of such compound, and (b) any of the forms of such compound in the medium in which the compound is being considered when named. For example, reference herein to a compound such as R-COOH, encompasses reference to any one of: for example, R- COOH(s), R-COOH(sol), and R-COO-(sol). In this example, R-COOH(s) refers to the solid compound, as it could be for example in a tablet or some other solid pharmaceutical composition or preparation; R-COOH(sol) refers to the undissociated form of the compound in a solvent; and R-COO-(sol) refers to the dissociated form of the compound in a solvent, such as the dissociated form of the compound in an aqueous environment, whether such dissociated form derives from R-COOH, from a salt thereof, or from any other entity that yields R-COO- upon dissociation in the medium being considered. In another example, an expression such as “exposing an entity to compound of formula R- COOH” refers to the exposure of such entity to the form, or forms, of the compound R- COOH that exists, or exist, in the medium in which such exposure takes place. In still another example, an expression such as “reacting an entity with a compound of formula R- COOH” refers to the reacting of (a) such entity in the chemically relevant form, or forms, of such entity that exists, or exist, in the medium in which such reacting takes place, with (b) the chemically relevant form, or forms, of the compound R-COOH that exists, or exist, in the medium in which such reacting takes place. In this regard, if such entity is for example in an aqueous environment, it is understood that the compound R-COOH is in such same medium, and therefore the entity is being exposed to species such as R- COOH(aq) and/or R-COO-(aq), where the subscript “(aq)” stands for “aqueous” according to its conventional meaning in chemistry and biochemistry. A carboxylic acid functional group has been chosen in these nomenclature examples; this choice is not intended, however, as a limitation but it is merely an illustration. It is understood that analogous examples can be provided in terms of other functional groups, including but not limited to hydroxyl, basic nitrogen members, such as those in amines, and any other group that interacts or transforms according to known manners in the medium that contains the compound. Such interactions and transformations include, but are not limited to, dissociation, association, tautomerism, solvolysis, including hydrolysis, solvation, including hydration, protonation, and deprotonation. No further examples in this regard are provided herein because these interactions and transformations in a given medium are known by any one of ordinary skill in the art.

Any formula given herein is also intended to represent unlabeled forms as well as isotopically labeled forms of the compounds. Isotopically labeled compounds have structures depicted by the formulas given herein except that one or more atoms are replaced by an atom having a selected atomic mass or mass number in an enriched form. Examples of isotopes that can be incorporated into compounds of the invention in a form that exceeds natural abundances include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, and iodine, such as ²H (or chemical symbol D), ³H (or chemical symbol T), ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S, ¹⁸F, ³⁶Cl, and ¹²⁵I, respectively. Such isotopically labelled compounds are useful in metabolic studies (preferably with ¹⁴C), reaction kinetic studies (with, for example ²H or ³H), detection or imaging techniques [such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT)] including drug or substrate tissue distribution assays, or in radioactive treatment of patients. In particular, an ¹⁸F or ¹¹C labeled compound may be particularly preferred for PET or SPECT studies. Further, substitution with heavier isotopes such as deuterium (i.e., ²H, or D) may afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half- life or reduced dosage requirements. Isotopically labeled compounds of this invention can generally be prepared by carrying out the procedures disclosed in the schemes or in the examples and preparations described below by substituting a readily available isotopically labeled reagent for a non-isotopically labeled reagent.

The term Cn-m alkyl refers to an aliphatic chain, whether straight or branched, with a total number N of carbon members in the chain that satisfies n < N < m, with m > n.

When the same plurality of substituents is assigned to various groups, the specific individual substituent assignment to each of such groups is meant to be independently made with respect to the specific individual substituent assignments to the remaining groups. By way of illustration, but not as a limitation, if each of groups Q and R can be H or F, the choice of H or F for Q is made independently of the choice of H or F for R, so the choice of assignment for Q does not determine or condition the choice of assignment for R, or vice-versa, unless it is expressly indicated otherwise. Illustrative claim recitation in this regard would read as “each of Q and R is independently H or F”, or “each of Q and R is independently selected from the group consisting of H and F”.

In another example, a zwitterionic compound would be encompassed herein by referring to a compound that is known to form a zwitterion, even if it is not explicitly named in its zwitterionic form. Terms such as zwitterion, zwitterions, and their synonyms zwitterionic compound(s) are standard IUPAC-endorsed names that are well known and part of standard sets of defined scientific names. In this regard, the name zwitterion is assigned the name identification CHEBI:27369 by the Chemical Entities of Biological Interest (ChEBI) dictionary of molecular entities. As generally well known, a zwitterion or zwitterionic compound is a neutral compound that has formal unit charges of opposite sign. Sometimes these compounds are referred to by the term “inner salts”. Other sources refer to these compounds as “dipolar ions”, although the latter term is regarded by still other sources as a misnomer. As a specific example, aminoethanoic acid (the amino acid glycine) has the formula H₂NCH₂COOH, and it exists in some media (in this case in neutral media) in the form of the zwitterion ⁺H₃NCH₂COO-. Zwitterions, zwitterionic compounds, inner salts and dipolar ions in the known and well-established meanings of these terms are within the scope of this invention, as would in any case be so appreciated by those of ordinary skill in the art. Because there is no need to name each and every embodiment that would be recognized by those of ordinary skill in the art, no structures of the zwitterionic compounds that are associated with the compounds of this invention are given explicitly herein. They are, however, part of the embodiments of this invention. No further examples in this regard are provided herein because the interactions and transformations in a given medium that lead to the various forms of a given compound are known by any one of ordinary skill in the art.

When referring to any formula given herein, the selection of a particular moiety from a list of possible species for a specified variable is not intended to define the same choice of the species for the variable appearing elsewhere. In other words, where a variable appears more than once, the choice of the species from a specified list is independent of the choice of the species for the same variable elsewhere in the formula, unless stated otherwise.

By way of a first example on substituent terminology, if substituent S¹ _example is one of S₁ and S₂, and substituent S² _example is one of S₃ and S₄, then these assignments refer to embodiments of this invention given according to the choices S¹ _example is S₁ and S² _example is

S₃; S¹ _example is S₁ and S² _example is S₄ S¹ _example is S₂ and S² _example is S₃ ; S¹ _example is S₂ and

S² _example is S₄; and equivalents of each one of such choices. The shorter terminology “S¹ _example is one of Si and S2, and S² _example is one of S3 and S4” is accordingly used herein for the sake of brevity, but not by way of limitation. The foregoing first example on substituent terminology, which is stated in generic terms, is meant to illustrate the various substituent assignments described herein.

Furthermore, when more than one assignment is given for any member or substituent, embodiments of this invention comprise the various groupings that can be made from the listed assignments, taken independently, and equivalents thereof. By way of a second example on substituent terminology, if it is herein described that substituent S_example is one of Si, S2, and S3, this listing refers to embodiments of this invention for which S_example is S₁; S_example is S₂ ; S_example is S₃ ; S_example is one of S₁ and S₂ ; S_example is one of S₁ and S₃; S_example is one of S₂ and S₃; S_example is one of S₁, S₂ and S₃; and S_example is any equivalent of each one of these choices. The shorter terminology “S_example is one of S₁, S₂, and S₃” is accordingly used herein for the sake of brevity, but not by way of limitation. The foregoing second example on substituent terminology, which is stated in generic terms, is meant to illustrate the various substituent assignments described herein.

The nomenclature “C_i-C_j” with j > i, when applied herein to a class of substituents, is meant to refer to embodiments of this invention for which each and every one of the number of carbon members, from i to j including i and j, is independently realized. By way of example, the term C₁-C₃ refers independently to embodiments that have one carbon member (C₁), embodiments that have two carbon members (C₂), and embodiments that have three carbon members (C₃).

Embodiments of this invention include compounds of Formula (I),

wherein

X-Y-Z is selected from the group consisting of:

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

wherein

L is selected from the group consisting of: CH₂, NH, CH(CH₃), and C(=O); R^c is halo or C_1-6alkyl; and

R^d is selected from the group consisting of: H, halo, and C_1-6alkyl; or a pharmaceutically acceptable salt, isotope, N-oxide, solvate, or stereoisomer thereof.

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein R¹ is C_1-4alkyl or C_1-4haloalkyl.

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein

wherein

R^b is C_1-4alkyl substituted with one OH member, and R^a is C_1-4alkyl. An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein R³ is H.

An additional embodiment of the invention is a compound of Formula (I) wherein R³ is F

An additional embodiment of the invention is a compound of Formula (I) wherein L is CH₂

An additional embodiment of the invention is a compound of Formula (I) wherein L is NH.

An additional embodiment of the invention is a compound of Formula (I) wherein L is CH(CH₃).

An additional embodiment of the invention is a compound of Formula (I) wherein L is C(=O).

An additional embodiment of the invention is a compound of Formula (I) wherein

wherein R^c is halo or C_1-4alkyl; and

R^d is selected from the group consisting of: H, halo and C_1-4alkyl.

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein

R^c is halo or C_1-4alkyl; and

R^d is selected from the group consisting of: H, halo, and C_1-4alkyl. An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the invention is a compound of Formula (I) wherein

An additional embodiment of the current invention is a compound selected from the compounds shown below in Table 1 , and, optionally, pharmaceutically acceptable salts, isotopes, N-oxides, solvates, and stereoisomers thereof:

Table 1

A further embodiment of the current invention is a compound selected from the group consisting of:

(S*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1 -trifluoropropan-2-yl)oxy)indolin-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-( 1 -(2-Chloro-6-fluorobenzy l)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(S*)-2-( 1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; and Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one; and pharmaceutically acceptable salts, isotopes, N-oxides, solvates, and stereoisomers thereof:

An additional embodiment of the invention is a compound of Formula (I) having the Formula (IA):

wherein wherein is a single or double bond; R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

wherein

L is selected from the group consisting of: CH₂, CH(CH₃), and C(=O); R^c is halo or C_1-6alkyl; and R^d is halo or C_1-6alkyl; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

An additional embodiment of the invention is a compound of Formula (I) having the Formula (IB):

wherein

R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

L is NH:

R^c is halo; and R^d is halo; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

An additional embodiment of the invention is a compound of Formula (I) having the Formula (IC):

wherein

R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

L is CH₂:

R^c is halo; and R^d is halo; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof. Also within the scope of the invention are enantiomers and diastereomers of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)). Also within the scope of the invention are the pharmaceutically acceptable salts, N-oxides or solvates of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)). Also within the scope of the invention are the pharmaceutically acceptable prodrugs of compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)), and pharmaceutically active metabolites of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)). Also within the scope of the invention are isotopic variations of compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)), such as, e.g., deuterated compounds of Formula (I). Also within the scope of the invention are the pharmaceutically acceptable salts, N-oxides or solvates of the isotopic variations of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)). Also within the scope of the invention are the pharmaceutically acceptable prodrugs of the isotopic variations of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)), and pharmaceutically active metabolites of the isotopic variations of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC)).

Even though the compounds of embodiments of the present invention (including their pharmaceutically acceptable salts and pharmaceutically acceptable solvates) can be administered alone, they will generally be administered in admixture with a pharmaceutically acceptable carrier, a pharmaceutically acceptable excipient and/or a pharmaceutically acceptable diluent selected with regard to the intended route of administration and standard pharmaceutical or veterinary practice.

Thus, particular embodiments of the present invention are directed to pharmaceutical and veterinary compositions comprising compounds of Formula (I) and at least one pharmaceutically acceptable carrier, pharmaceutically acceptable excipient, and/or pharmaceutically acceptable diluent. By way of example, in the pharmaceutical compositions of embodiments of the present invention, the compounds of Formula (I) may be admixed with any suitable binder(s), lubricant(s), suspending agent(s), coating agent(s), solubilizing agent(s), and combinations thereof.

An embodiment of the invention relates to a pharmaceutical composition comprising an effective amount of at least one compound selected from compounds of Formula (I), and pharmaceutically acceptable salts, isotopes, N-oxides, solvates, and stereoisomers thereof, in accordance with any embodiment described herein; and at least one pharmaceutically acceptable excipient.

An additional embodiment of the invention is a pharmaceutical composition comprising:

(A) an effective amount of at least one compound selected from compounds of Formula (I)

wherein

X-Y-Z is selected from the group consisting of:

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

L is selected from the group consisting of: CH₂, NH, CH(CH₃), and C(=O); R^c is halo or C_1-6alkyl; and R^d is selected from the group consisting of: H, halo, and C_1-6alkyl; or pharmaceutically acceptable salts, isotopes, N-oxides, solvates, or stereoisomers thereof; and (B) at least one pharmaceutically acceptable excipient.

An additional embodiment of the invention is a pharmaceutical composition comprising an effective amount of a compound shown in Table 1 ( e.g a compound selected from Examples 1-22), or a pharmaceutically acceptable salt, isotope, N-oxide, solvate, or stereoisomer of the compound of Table 1, a pharmaceutically acceptable prodrug of the compound of Table 1, or a pharmaceutically active metabolite of the compound of Table 1; and at least one pharmaceutically acceptable excipient.

Solid oral dosage forms such as, tablets or capsules, containing one or more compounds of the present invention may be administered in at least one dosage form at a time, as appropriate. It is also possible to administer the compounds in sustained release formulations.

Additional oral forms in which the present inventive compounds may be administered include elixirs, solutions, syrups, and suspensions; each optionally containing flavoring agents and coloring agents.

Alternatively, one or more compounds of Formula (I) can be administered by inhalation (intratracheal or intranasal) or in the form of a suppository or pessary, or they may be applied topically in the form of a lotion, solution, cream, ointment or dusting powder. For example, they can be incorporated into a cream comprising, consisting of, and/or consisting essentially of an aqueous emulsion of polyethylene glycols or liquid paraffin. They can also be incorporated, at a concentration of between about 1 % and about 10 % by weight of the cream, into an ointment comprising, consisting of, and/or consisting essentially of a wax or soft paraffin base together with any stabilizers and preservatives as may be required. An alternative means of administration includes transdermal administration by using a skin or transdermal patch.

The pharmaceutical compositions of the present invention (as well as the compounds of the present invention alone) can also be injected parenterally, for example, intracavernosally, intravenously, intramuscularly, subcutaneously, intradermally, or intrathecally. In this case, the compositions will also include at least one of a suitable carrier, a suitable excipient, and a suitable diluent.

For parenteral administration, the pharmaceutical compositions of the present invention are best used in the form of a sterile aqueous solution that may contain other substances, for example, enough salts and monosaccharides to make the solution isotonic with blood.

For buccal or sublingual administration, the pharmaceutical compositions of the present invention may be administered in the form of tablets or lozenges, which can be formulated in a conventional manner.

By way of further example, pharmaceutical compositions containing at least one of the compounds of Formula (I) as the active ingredient can be prepared by mixing the compound(s) with a pharmaceutically acceptable carrier, a pharmaceutically acceptable diluent, and/or a pharmaceutically acceptable excipient according to conventional pharmaceutical compounding techniques. The carrier, excipient, and diluent may take a wide variety of forms depending upon the desired route of administration (e.g., oral, parenteral, etc.). Thus, for liquid oral preparations such as, suspensions, syrups, elixirs and solutions, suitable carriers, excipients and diluents include water, glycols, oils, alcohols, flavoring agents, preservatives, stabilizers, coloring agents and the like; for solid oral preparations such as, powders, capsules, and tablets, suitable carriers, excipients and diluents include starches, sugars, diluents, granulating agents, lubricants, binders, disintegrating agents and the like. Solid oral preparations also may be optionally coated with substances such as, sugars, or be enterically coated so as to modulate the major site of absorption and disintegration. For parenteral administration, the carrier, excipient and diluent will usually include sterile water, and other ingredients may be added to increase solubility and preservation of the composition. Injectable suspensions or solutions may also be prepared utilizing aqueous carriers along with appropriate additives such as, solubilizers and preservatives.

According to particular embodiments, a therapeutically effective amount of a compound of Formula (I) or a pharmaceutical composition thereof may comprise a dose range from about 0.1 mg to about 3000 mg, or any particular amount or range therein, in particular from about 1 mg to about 1000 mg, or any particular amount or range therein, of active ingredient in a regimen of about 1 to about (4x) per day for an average (70 kg) human; although, it is apparent to one skilled in the art that the therapeutically effective amount for a compound of Formula (I) will vary as will the diseases, syndromes, conditions, and disorders being treated.

An embodiment of the present invention is directed to a pharmaceutical composition for oral administration, comprising a compound of Formula (I) in an amount of from about 1 mg to about 500 mg.

Advantageously, a compound of Formula (I) may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three and (4x) daily.

Optimal dosages of a compound of Formula (I) to be administered may be readily determined and will vary with the particular compound used, the mode of administration, the strength of the preparation, and the advancement of the disease, syndrome, condition or disorder. In addition, factors associated with the particular subject being treated, including subject gender, age, weight, diet and time of administration, will result in the need to adjust the dose to achieve an appropriate therapeutic level and desired therapeutic effect. The above dosages are thus exemplary of the average case. There can be, of course, individual instances wherein higher or lower dosage ranges are merited, and such are within the scope of this invention.

Compounds of Formula (I) may be administered in any of the foregoing compositions and dosage regimens or by means of those compositions and dosage regimens established in the art whenever use of a compound of Formula (I) is administered to a subject in need thereof.

According to particular embodiments, one or more compounds of Formula (I) are useful in methods for treating, ameliorating and / or preventing a disease, a syndrome, a condition or a disorder that is affected by the inhibition of DHODH enzymatic activity.

An additional embodiment of the invention relates to the use of compounds of Formula (I), e.g., by inhibiting dihydroorotate oxygenase enzyme activity, in treating disorders like inflammatory disorders, autoimmune disorders, or cancer;

wherein

X-Y-Z is selected from the group consisting of:

R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

L is selected from the group consisting of: CH₂, NH, CH(CH₃), and C(=O); R^c is halo or C_1-6alkyl; and

R^d is selected from the group consisting of: H, halo, and C_1-6alkyl; or pharmaceutically acceptable salts, isotopes, N-oxides, solvates, or stereoisomers thereof.

In a further aspect the present invention provides a method for inhibiting or altering Dihydroorotate Dehydrogenase (DHODH) enzymatic activity, the method comprising contacting DHODH with any compound of Formula (I), aspect or embodiment disclosed herein, thereby inhibiting or otherwise altering DHODH enzymatic activity.

An additional embodiment of the present invention provides methods for treating diseases, disorders, or medical conditions mediated or otherwise affected by dihydroorotate dehydrogenase (DHODH) enzyme activity comprising administering a compound of Formula (I) to a subject in need thereof.

As used herein, the term "DHODH inhibitor" may refer to an agent that inhibits or reduces DHODH activity.

In one embodiment, the term “therapeutically effective amount” (or “effective amount”) refers to the amount of a compound of the present invention that, when administered to a subject, is effective to (1) at least partially alleviate, inhibit, prevent, and / or ameliorate a condition, or a disorder or a disease (i) mediated by DHODH enzymatic activity; or (ii) associated with DHODH enzymatic activity; or (iii) characterized by activity (normal or abnormal) of DHODH enzyme; or (2) reduce or inhibit the activity of DHODH enzyme; or (3) reduce or inhibit the expression of DHODH; or (4) modify the protein levels of DHODH. Without being bound by a particular theory, DHODH inhibitors are believed to act by inhibiting nucleic acid synthesis, cell cycle arrest or altering post- translational glycosylation of proteins involved in regulating myeloid differentiation within progenitor tumor cells.

An additional embodiment of the invention is a method of treating a subject suffering from or diagnosed with a disease, disorder, or medical condition mediated or otherwise affected by DHODH enzymatic activity, comprising administering to a subject in need of such treatment an effective amount of at least one compound selected from: compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC), such as a compound of Table 1), enantiomers and diastereomers of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC), such as a compound of Table 1), isotopic variations of the compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC), such as a compound of Table 1), and pharmaceutically acceptable salts of all of the foregoing. Stated another way, according to an embodiment, a method of treating a subject suffering from or diagnosed with a disease, disorder, or medical condition, such as cancer, comprises administering to the subject an effective amount of at least one compound selected from: compounds of Formula (I) (as well as compounds of Formula (IA), (IB), and (IC), such as a compound of Table 1), and pharmaceutically acceptable salts of all the foregoing (e.g., by inhibiting or otherwise altering dihydroorotate oxygenase enzyme activity in the subject).

In another embodiment, inhibitors of DHODH of the present invention may be used for the treatment of immunological diseases including, but not limited to, autoimmune and inflammatory disorders, e.g. arthritis, inflammatory bowel disease, gastritis, ankylosing spondylitis, ulcerative colitis, pancreatitis, Crohn’s disease, celiac disease, multiple sclerosis, systemic lupus erythematosus, lupus nephritis, rheumatic fever, gout, organ or transplant rejection, chronic allograft rejection, acute or chronic graft- versus-host disease, dermatitis including atopic, dermatomyositis, psoriasis, Behcet’s diseases, uveitis, myasthenia gravis, Grave’s disease, Hashimoto thyroiditis, Sjogren’s syndrome, blistering disorders, antibody-mediated vasculitis syndromes, immune-complex vasculitides, allergic disorders, asthma, bronchitis, chronic obstructive pulmonary disease (COPD), cystic fibrosis, pneumonia, pulmonary diseases including edema, embolism, fibrosis, sarcoidosis, hypertension and emphysema, silicosis, respiratory failure, acute respiratory distress syndrome, BENTA disease, berylliosis, and polymyositis.

As used herein, unless otherwise noted, the term “affect” or “affected” (when referring to a disease, disorder, or medical condition that is affected by the inhibition or alteration of DHODH enzymatic activity) includes a reduction in the frequency and / or severity of one or more symptoms or manifestations of said disease, syndrome, condition or disorder; and / or includes the prevention of the development of one or more symptoms or manifestations of said disease, syndrome, condition or disorder or the development of the disease, condition, syndrome or disorder.

An additional embodiment of the invention provides a method of treatment of cancer comprising administering to a subject in need thereof, a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, isotope, N- oxide, solvate, or stereoisomer thereof.

According to an embodiment, the cancer is selected from but not limited to, lymphomas, leukemias, carcinomas, and sarcomas.

An additional embodiment of the invention provides the use of a compound of Formula (I), or a pharmaceutically acceptable salt, isotope, N-oxide, solvate, or stereoisomer thereof, for the treatment of one or more cancer types.

According to particular embodiments, the uses and methods of treatment described herein are directed to the treatment of cancer, wherein the cancer is selected from but not limited to: leukemias including but not limited to acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), (acute) T-cell leukemia, acute monocytic leukemia, acute promyelocytic leukemia (APL), bisphenotypic B myelomonocytic leukemia, chronic myeloid leukemia (CML), chronic myelomonocytic leukemia (CMML), large granular lymphocytic leukemia, plasma cell leukemia, and also myelodysplastic syndrome (MDS), which can develop into an acute myeloid leukemia, lymphomas including but not limited to AIDS -related lymphoma, Hodgkin lymphoma, non-Hodgkin's lymphoma (NHL), T-non-Hodgkin lymphoma (T- NHL), subtypes of NHL such as Diffuse Large Cell Lymphoma (DLBCL), activated B-cell DLBCL, germinal center B-cell DLBCL, double-hit lymphoma and double-expressor lymphoma; anaplastic large cell lymphoma, marginal B cell lymphoma and primary mediastinal B-cell lymphoma, immunoblastic large cell lymphoma, Burkitt lymphoma, follicular lymphoma, hairy cell leukemia, Hodgkin's disease, mantle cell lymphoma (MCL), lymphoplasmatic lymphoma, precursor B -lymphoblastic lymphoma, lymphoma of the central nervous system, small lymphocytic lymphoma (SLL) and chronic lymphocytic leukemia (CLL); T-cell NHL such as precursor T- lymphoblastic lymphoma/leukemia, peripheral T-cell lymphoma (PTCL), cutaneous T-cell lymphoma (CTCL), angioimmunoblastic T-cell lymphoma, extranodal natural killer T-cell lymphoma, enteropathy type T-cell lymphoma, subcutaneous panniculitis-like T-cell lymphoma, anaplastic large cell lymphoma sarcomas including but not limited to sarcoma of the soft tissue, gliosarcoma, osteosarcoma, malignant fibrous histiocytoma, lymphosarcoma, and rhabdomyosarcoma; and other cancers, such as solid tumors, including but not limited to breast cancer, colorectal carcinoma, gastric cancer, gliosarcoma, head & neck cancer, hepatocellular carcinoma, lung cancer, multiple myeloma, neuroblastoma, ovarian cancer, pancreatic cancer, prostate cancer, renal cell carcinoma and sarcoma.

In an embodiment, cancers that may benefit from a treatment with inhibitors of DHODH of the present invention include, but are not limited to, lymphomas, leukemias, carcinomas, and sarcomas, e.g. non-Hodgkin’s lymphoma, diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular lymphoma (FL), marginal zone lymphoma, T-cell lymphoma, Hodgkin’s lymphoma, Burkitt’s lymphoma, multiple myeloma, brain (gliomas), glioblastomas, breast cancer, colorectal/colon cancer, prostate cancer, lung cancer including non-small-cell, gastric cancer, endometrial cancer, melanoma, pancreatic cancer, liver cancer, kidney cancer, squamous cell carcinoma, ovarian cancer, sarcoma, osteosarcoma, thyroid cancer, bladder cancer, head & neck cancer, testicular cancer, Ewing’s sarcoma, rhabdomyosarcoma, medulloblastoma, neuroblastoma, cervical cancer, renal cancer, urothelial cancer, vulval cancer, esophageal cancer, salivary gland cancer, nasopharangeal cancer, buccal cancer, cancer of the mouth, and GIST (gastrointestinal stromal tumor).

In another embodiment of the present invention, the compounds of the present invention may be employed in combination with one or more other medicinal agents, more particularly with one or more anti-cancer agents, e.g. chemotherapeutic, anti-proliferative or immunomodulating agents, or with adjuvants in cancer therapy, e.g. immunosuppressive or anti-inflammatory agents. Additional non-limiting examples of anti-cancer agents that may be administered in combination with a compound of the present invention include biologic compounds, such as monoclonal antibodies (e.g., that mediate effector function upon binding to cancer cell-associated antigens, or block interaction of a receptor expressed on cancer cells with a soluble or cell bound ligand), bispecific antibodies that mediate immune cell redirection, etc. According to an embodiment, a method of treating cancer comprises administering an effective amount of a compound of the present invention (e.g., selected from compounds of Formula (I), such as a compound shown in Table 1, pharmaceutically acceptable salts, isotopes, N-oxides, solvates, and stereoisomers thereof) and an effective amount of one or more additional anti-cancer agents, wherein the method comprises administering the compound of the present invention and the additional anti-cancer agent(s) either simultaneously (e.g., as part of the same pharmaceutical composition) or sequentially. According to an embodiment, a pharmaceutical composition comprises an effective amount of a compound of the present invention (e.g., selected from compounds of Formula (I), such as a compound shown in Table 1, pharmaceutically acceptable salts, isotopes, N-oxides, solvates, and stereoisomers thereof), an effective amount of one or more additional anti-cancer agents, and optionally one or more excipients.

An additional embodiment of the invention provides the use of a compound of Formula (I), or pharmaceutically acceptable salts, isotopes, N-oxides, solvates, or stereoisomers thereof, as part of chemotherapeutic regimens for the treatment of cancers, lymphomas and leukemias alone or in combination with classic antitumoral compounds well known by the one skilled in the art.

GENERAL SYNTHETIC METHODS

Exemplary compounds useful in methods of the invention will now be described by reference to the illustrative synthetic schemes for their general preparation below and the specific examples that follow. Artisans will recognize that, to obtain the various compounds herein, starting materials may be suitably selected so that the ultimately desired substituents will be carried through the reaction scheme with or without protection as appropriate to yield the desired product. Alternatively, it may be necessary or desirable to employ, in the place of the ultimately desired substituent, a suitable group that may be carried through the reaction scheme and replaced as appropriate with the desired substituent. Unless otherwise specified, the variables are as defined above in reference to Formula (I). Reactions may be performed between the melting point and the reflux temperature of the solvent, and preferably between 0 °C and the reflux temperature of the solvent. Reactions may be heated employing conventional heating or microwave heating. Reactions may also be conducted in sealed pressure vessels above the normal reflux temperature of the solvent.

Abbreviations used in the instant specification, particularly the schemes and examples, are as follows in Table 2:

Table 2.

PREPARATIVE EXAMPLES

Exemplary compounds useful in methods of the invention will now be described by reference to the illustrative synthetic schemes for their general preparation below and the specific examples to follow.

According to SCHEME 1, a 1,2,4-triazol-5(4H)-one compound of formula (II), where PG is Bn, is prepared from ethyl 2-(benzyloxy)acetate in three steps. In a first step 2-(benzyloxy)acetohydrazide is prepared by the reaction of ethyl 2-(benzyloxy)acetate with hydrazine hydrate, in a suitable solvent such as EtOH, and the like; at temperatures ranging from 70-85 °C. Reaction of the hydrazide with an isocyanate of formula R^a-NCO, where R^a is C_1-6alkyl, in a suitable solvent such as water, and the like; provides the corresponding semicarbazide. Subsequent cyclization of the semicarbazide with a suitable base such as NaOH, in a suitable solvent such as water, provides a compound of formula (II), where PG is Bn.

Protecting group exchange of a compound of formula (II), where PG is Bn to a compound of formula (II) where PG is TBDPS, is achieved in two steps employing established methodologies, such as those described in T. W. Greene and P. G. M. Wuts, “Protective Groups in Organic Synthesis,” 3 ed., John Wiley & Sons, 1999. In a first step, deprotection of benzyl group is achieved under hydrogeno lytic conditions known to one skilled in the art provides the alcohol. For example, deprotection is achieved employing a palladium catalyst such Pd/C, and the like; under H₂; in a suitable solvent such as EtOH, MeOH, EtOAc, or a mixture thereof, preferably EtOH; with or without the presence HCl; for a period of 4 to 72 hrs. In a second step, protection of the corresponding alcohol as the silyl ether, is achieved with tert-butyldiphenylsilyl chloride, a suitable base such as imidazole, dimethylaminopyridine, pyridine, and the like; in a solvent such as DMF, DCM, and the like; at temperatures ranging from 0 °C to room temperature; affords a compound of formula (II) where PG is TBDPS.

According to SCHEME 2, a commercially available or synthetically accessible compound of formula (III), where R³ is H or F, is reacted with a commercially available or synthetically accessible alcohol compound of formula (IV), where R¹ is C_1-6alkyl or C_1-6haloalkyl; in the presence of a base such as NaH; in a suitable solvent such as THF, and the like; at temperatures ranging from 0 °C to ambient temperature, preferably 25 °C; to provide a compound of formula (V). According to the methods as described by Bartoli, et al in Tetrahedron Letters 1989, 30 (16): 2129-2132, a compound of formula (V) is reacted with a vinyl Grignard reagent like vinylmagnesium bromide; in a suitable solvent such as THF; at low temperature such as -40 °C; to afford an indole compound of the formula (VI). Similar transformation was also reported by Boyd E. M. et al, in Tetrahedron Letters 2012, 53, 3623-3626. An indole compound of formula (VI) is reduced in the presence of a suitable reductant such as sodium cyanoborohydride, sodium triacetoxyborohydride, or the like, and a suitable acid such as acetic acid, or TFA, and the like, at temperatures ranging around room temperature, for a period of 12 to 24 hours, to afford an indoline compound of formula (VII).

According to SCHEME 3, a commercially available or synthetically accessible compound of formula (VIII), where R³ is H or F, is reacted with a commercially available or synthetically accessible alcohol compound of formula (IV), where R¹ is C_1-6alkyl or C_1-6haloalkyl; in the presence of a base such as NaH; in a suitable solvent such as THF or the like; at temperatures ranging from 0 °C to ambient temperature, preferably 25 °C; to provide a compound of formula (IX). The nitro group in a compound of formula (IX) is selectively reduced to give the corresponding amino compound of formula (X) by employing iron or zinc in the presence of ammonium chloride in a suitably mixed solvents such as methanol and water in a temperature ranging from 0 °C to 25 °C in 1-2 hours. According to the methods as described by Song, P. et al in Bioorganic & Medicinal

Chemistry 2015, 23: 1858-1868, a compound of formula (X) is reacted with a diazotizing reagent such as sodium nitrite, or the like; in a suitable solvent such as aqueous concentrated hydrochloric acid; at low temperature such as -10 °C; to afford an indazole compound of the formula (XI).

According to SCHEME 4, 4-bromo-2,6-difluorobenzonitrile is reacted with an alcohol compound of formula (IV), where R¹ is C_1-6alkyl or C_1-6haloalkyl; in the presence of a base such as LiHMDS, or NaH, and the like; in a suitable solvent such as THF or the like; at temperatures ranging from -78 °C to 25 °C; to selectively provide a compound of formula (XII), where R³ is H. According to the methods as described in WO 2015112445, Pub. July 30, 2015, a compound of formula (XII) is reacted with anhydrous hydrazine, or hydrazine hydrate; in a suitable solvent such as n-butyl alcohol; under refluxing conditions at a temperature ranging from 80-110 °C for 12-24 hours; to afford an indazole compound of the formula (XIII). The NH group of a compound of the formula (XIII) is selectively protected by a suitable group to afford a N-protected compound of formula (XIV), where PG¹ is benzyl or p-methoxy benzyl (PMB). For example, a compound of formula (XIII) is reacted with p-methoxybenzyl chloride in the presence of base such as KOH in a suitable solvent such as DMSO at ambient temperature such as 25 °C to provide a compound of formula (XIV), where PG¹ is PMB.

According to SCHEME 5, commercially available or synthetically accessible methyl 1,2-dihydro-2-oxopyridine-4-carboxylate is reacted with benzyl bromide; in presence of a suitable base such as K₂CO₃, and the like; in a suitable solvent such as DMF, and the like; at temperatures ranging from 0 °C to room temperature; for a period of 12-19 h; to provide methyl 1-benzyl-2-oxo-1,2-dihydropyridine-4-carboxylate. Methyl 1-benzyl- 2-oxo-1,2-dihydropyridine-4-carboxylate is reduced to 1-benzyl-4- (hydroxymethyl)pyridin-2(1H)-one, employing a suitable reducing agent such as LiBH4, and the like; in a suitable solvent such as THF, and the like; at temperatures ranging from 0 °C to room temperature; for a period of 12-19 h. 1-Benzyl-4-(hydroxymethyl)pyridin- 2(1H)-one is brominated employing conditions known to one skilled in the art, for example, reaction with phosphorus oxybromide, in a suitable solvent such as chloroform, for a period of 18-24 h, to provide Racemic 1-benzyl-4-((5-bromo-7-(( 1,1,1 - trifluoropropan-2-yl)oxy)indolin-1-yl)methyl)pyridin-2(1H)-one. SCHEME 6

According to SCHEME 6, compound of formula (XV) (which encompasses compounds of formulas (VI), (VII), and (XI)), where X is NH, is reacted with a compound of formula (XVI), (XVII) or 1-benzyl-4-((5-bromo-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-1-yl)methyl)pyridin-2(1H)-one; where L is CH₂ or CH(CH₃), and R^c and R^d are as defined in claim 1; in the presence of a suitable base such as K₂CO₃, CS₂CO₃, triethylamine, Hunig base, and the like; in a suitable solvent such as dimethylsulfoxide (DMSO), DMF, THF, MeCN, and the like; to afford a N-alkylated compound of formula (XVIII), where R¹ is C_1-6alkyl or C_1-6haloalkyl, and R³ is H or F. A compound of formula (XVIII) is reacted with a triazolone of formula (II), where

R^a is C_1-6alkyl, and PG is a protecting group such as benzyl, para-methoxy benzyl, TBDPS, TIPS, TBS, and the like, in an Ullmann-type aromatic amination reaction. For example, the reaction of compound of formula (XVIII) with a compound of formula (II); in the presence of a Cu(I) or Cu(II) salt such as Cul; with or without an additive such as KI; a ligand such as trans-N,N'-cyclohexane-1,2-diamine, trans-N,N'-dimethylcyclohexane- 1 ,2-diamine, and the like; a base such as CS₂CO₃, K₂CO₃, K₃PO₄, K₂HPO₄, KHCO₃, Na₂CO₃, NaHCO₃, and the like; in a suitable solvent such as 1,4-dioxane, and the like; at temperatures ranging from 80 to 110 °C; for a period of about 16 to 24 hours. Subsequent deprotection of the protecting group, where PG is a alcohol protecting group as defined above; is deprotected employing conditions known to those skilled in the art (Greene, Protecting Groups in Organic Synthesis; John Wiley & Sons) to afford a compound of Formula (I). For example, when PG is TBDPS, deprotection is achieved by treatment with tetrabutylammonium fluoride in a solvent such as THF at room temperature; or triethylammonium fluoride in a solvent such as THF at room temperature at 60 °C; to afford the compound of Formula (I), where R² is defined as described in claim 1, R³ is F. When PG is benzyl, deprotection is achieved by treatment with neat TFA at 60 °C for 18 hours or by treatment with BCl₃ in DCM at reduced temperatures such as 0 °C for 1 to 4 hours or by treatment with hydrogen gas in the presence of catalytic palladium on carbon in a solvent such as EtOH, EtOAc, or the like, at room temperature; to afford the compound of Formula (I).

In an alternate method, prior to deprotection of the PG is TBDPS moiety, a

triacetoxyborohydride, or the like, and a suitable acid such as acetic acid, HCl, or TFA, and the like, at temperatures ranging from 0°C to room temperature, for a period of 12 to 24 hrs.

According to SCHEME 7, a compound of formula (XV) (which encompasses compounds of formulas (VI), and (VII)), where X is NH; is condensed with a commercially available or synthetically accessible carboxylic acid compound of formula (XIX), where R^c and R^d are as defined as claim 1 ; in the presence of the Mukaiyama reagent (2-chloro-1-methylpyridinium iodide, CMPI) and a suitable base such as triethylamine, Hiinig base, and the like; in a suitable solvent such as DCM, DCE, and the like; at temperatures ranging from 50 °C to 80 °C; to provide an amide compound of

Subsequent Ullmann-type aromatic amination reaction with a compound of formula (II), followed by deprotection according to methods previously described provides a compound of Formula (I) where R⁴

According to SCHEME 8, a compound of formula (XIV) is reacted with a commercially available or synthetically accessible aromatic halide compound of formula (XX), where R^c is halo or C_1-6alkyl, and R^d is selected from the group consisting of: H; halo; and C_1-6alkyl; by employing copper catalyzed arylation conditions to provide a compound of formula (XXI). For example, reaction of compound of formula (XIV) is reacted with 1-chloro-3-fluoro-2-iodobenzene; in the presence of a Cu(I) or Cu(II) salt such as Cul; with an additive such as KI; a ligand such as trans-N,N'- cyclohexane- 1,2- diamine, and the like; a base such as CS₂CO₃, K₂CO₃, Na₂CO₃, , and the like; in a suitable solvent such as 1,4-dioxane, and the like; at temperatures ranging from 90 to 110 °C; for a period of about 16 to 24 hours; to provide a compound of formula (XXI). Subsequent Ullmann-type aromatic amination reaction with a compound of formula (II), followed by deprotection according to methods previously described provides a compound of Formula

Compounds of Formula (I) may be converted to their corresponding salts using methods known to one of ordinary skill in the art. For example, an amine of Formula (I) is treated with trifluoroacetic acid, HCl, or citric acid in a solvent such as Et₂O, CH₂Cl₂,

THF, MeOH, chloroform, or isopropanol to provide the corresponding salt form. Alternately, trifluoroacetic acid or formic acid salts are obtained as a result of reverse phase HPLC purification conditions. Crystalline forms of pharmaceutically acceptable salts of compounds of Formula (I) may be obtained in crystalline form by recry stallizati on from polar solvents (including mixtures of polar solvents and aqueous mixtures of polar solvents) or from non-polar solvents (including mixtures of non-polar solvents).

Where the compounds according to this invention have at least one chiral center, they may accordingly exist as enantiomers. Where the compounds possess two or more chiral centers, they may additionally exist as diastereomers. It is to be understood that all such isomers and mixtures thereof are encompassed within the scope of the present invention.

Compounds prepared according to the schemes described above may be obtained as single forms, such as single enantiomers, by form-specific synthesis, or by resolution. Compounds prepared according to the schemes above may alternately be obtained as mixtures of various forms, such as racemic (1:1) or non-racemic (not 1:1) mixtures. Where racemic and non-racemic mixtures of enantiomers are obtained, single enantiomers may be isolated using conventional separation methods known to one of ordinary skill in the art, such as chiral chromatography, recrystallization, diastereomeric salt formation, derivatization into diastereomeric adducts, biotransformation, or enzymatic transformation. Where regioisomeric or diastereomeric mixtures are obtained, as applicable, single isomers may be separated using conventional methods such as chromatography or crystallization.

The following specific examples are provided to further illustrate the invention and various preferred embodiments. EXAMPLES

In obtaining the compounds described in the examples below and the corresponding analytical data, the following experimental and analytical protocols were followed unless otherwise indicated.

Unless otherwise stated, reaction mixtures were magnetically stirred at room temperature (rt) under a nitrogen atmosphere. Where solutions were “dried,” they were generally dried over a drying agent such as Na₂SO₄ or MgSCU Where mixtures, solutions, and extracts were “concentrated”, they were typically concentrated on a rotary evaporator under reduced pressure.

Normal-phase silica gel chromatography (FCC) was performed on silica gel (SiO₂) using prepacked cartridges.

Preparative supercritical fluid high performance liquid chromatography (SFC) was performed either on a Thar 80 Prep-SFC system, or Waters 80Q Prep-SFC system from Waters. The ABPR was set to 100bar to keep the CO₂ in SF conditions, and the flow rate may verify according to the compound characteristics, with a flow rate ranging from 50g/min to 70g/min. The column temperature was ambient temperature.

Preparative chiral SFC (Stationary phase: DAICEL CHIRALPAK AD-H, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - i-PrOH (0.1% NH₃H₂O) (B), gradient elution: 15% B in A , flow rate: 50 mL/min).

Preparative supercritical fluid high performance liquid chromatography (SFC) Column: Phenomenex-Cellulose-2, 5 μm, 250 x 30 mm; Mobile phase: A: supercritical CO₂, B: MeOH (0.1% NH₃ H₂O), gradient elution: 25% B in A , flow rate: 60 mL/min).

Preparative SFC (Stationary phase: Phenomenex-Amylose-1, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - EtOH (0.1% NH₃H₂O) (B), gradient elution: 35% B in A , flow rate: 50 mL/min).

Preparative chiral SFC (Stationary phase: Phenomenex-Amylose-1, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - EtOH (0.1% NH₃H₂O) (B), gradient elution:

15% B in A , flow rate: 50 mL/min). Preparative reverse phase HPLC (Stationary phase: Boston Prime Cl 8, 5 μm, 150 x 30 mm; Mobile phase: H₂O (0.04% NH₃H₂O + 10 mM NH4HCO₃) (A) - MeCN (B), gradient elution: 55 - 85% B in A over 8 min, flow rate: 25 mL/min).

Preparative reverse phase HPLC (Stationary phase: Phenomenex Gemini-NX, 5 μm, 150 x 30 mm; Mobile phase: water (0.04% NH₃H₂O + 10 mM NH₄HCO₃) (A) - MeCN (B), gradient elution: 52 - 82% B in A over 8 min, flow rate: 25 mL/min).

Mass spectra (MS) were obtained on a SHIMADZU LCMS-2020 MSD or Agilent 1200\G6110A MSD using electrospray ionization (ESI) in positive mode unless otherwise indicated. Calculated (calcd.) mass corresponds to the exact mass. Nuclear magnetic resonance (NMR) spectra were obtained on Bruker model AVIII

400 spectrometers. Definitions for multiplicity are as follows: s = singlet, d = doublet, t= triplet, q = quartet, m = multiplet, br = broad, dd = doublet of doublets, ddd = doublet of doublet of doublets, td = triplet of doublets, dt = doublet of triplets, spt = septet, quin = quintet, m = multiplet. It will be understood that for compounds comprising an exchangeable proton, said proton may or may not be visible on an NMR spectrum depending on the choice of solvent used for running the NMR spectrum and the concentration of the compound in the solution.

Chemical names were generated using ChemDraw Ultra 17.1 (CambridgeSoft Corp., Cambridge, MA) or OEMetaChem VI.4.0.4 (Open Eye). Compounds designated as R* or S* are enantiopure compounds where the absolute configuration was not determined.

Intermediate 1: Racemic 5-Bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole. Step A, Racemic 4-Bromo- 1 -nitro-2-((1,1,1-trifluoropropan-2-yl)oxy)benzene. To a solution of 4-bromo-2-fluoro-1-nitrobenzene (20.3 g, 92.3 mmol, 1.0 eq.) in THF (200 mL) was added sodium hydride (7.38 g, 185 mmol, 2.0 eq. 60%) at 0 °C. The resulting solution was stirred at 0 °C for 30 minutes, and then 1 , 1 , 1 -trifluoropropan-2-ol (15.8 g 138 mmol, 1.5 eq.) was added slowly. The reaction mixture was warmed to room temperature and stirred for 5 h. TLC (petroleum ether: ethyl acetate = 5:1) showed the reaction was completed. The reaction was quenched with water (200 mL) and extracted with ethyl acetate (3 x 200 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue obtained was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the 4-bromo-1-nitro-2- ((1,1,1-trifluoropropan-2-yl)oxy)benzene as a yellow solid (28.5 g, 98% yield).

Step B, Racemic 5-Bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)-1H-indole. To a solution of 4-bromo-1-nitro-2-((1,1,1-trifluoropropan-2-yl)oxy)benzene (15.2 g, 48.4 mmol, 1.0 eq) in THF (200 mL) at -40 °C was added a THF solution (1 M) of vinylmagnesium bromide in (242 mL, 242 mmol) over a period of 20 min. The resulting reaction mixture was stirred at -40 °C for 6 h. The reaction was quenched with sat. aqueous NH₄Cl (200 mL). The mixture was extracted with ethyl acetate (3 x 200 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue obtained was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole as a red oil (5.2 g, 34.9% yield). LCMS: mass calcd. for C₁₁H₉BrF₃NO: 306.98, found 308.00 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.48 (br s, 1 H), 7.48 (d, J= 0.7 Hz, 1 H), 7.22 (t, J= 2.7 Hz, 1 H), 6.80 (s, 1 H), 6.50 (t, J= 2.6 Hz, 1 H), 4.80 (spt, J= 6.3 Hz, 1 H), 1.61 (s, 3 H) ppm.

Intermediate 2: Racemic 5-Bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)indoline.

To a solution of 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1, 1000 mg, 3.25 mmol, 1.0 eq.) in glacial acetic acid (10 mL) at 0 °C was added sodium cyanoborohydride (509.9 mg, 8.11 mmol, 2.5 eq.) slowly. The resulting reaction mixture was stirred at r.t. for overnight. Then the reaction was quenched with water (100 mL). The mixture was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (0-50 % ethyl acetate / petroleum ether) to afford the title compound as a red oil (750 mg, 74.5% yield). MS (ESI): mass calcd. for CiiHiiBrF₃NO: 309.0, found 310.0 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 6.98 (s, 1 H), 6.82 (s, 1 H),

4.54 (spt, J = 6.3 Hz, 1 H), 3.85 (br s, 1 H), 3.60 (t, J= 8.6 Hz, 2 H), 3.05 (t, J= 8.4 Hz, 2 H), 1.50 (d, J= 6.4 Hz, 3 H) ppm.

Intermediate 3: Racemic 6-Bromo- 1 -(4-methoxybenzyl)-4-((1,1,1-trifluoropropan-2- yl)oxy)-1H-indazol-3 -amine.

Step A. Racemic 4-Bromo-2-fluoro-6-(( 1.1.1 -trifluoropropan-2-yl)oxy)benzonitrile. To a solution of 4-bromo-2,6-difluorobenzonitrile (5.0 g, 22.9 mmol, 1.0 eq) in THF (50 mL) at -78 °C was added THF (1 M) of lithium bis(trimethylsilyl)amide (45.9 mL, 45.9 mmol, 2.0 eq) over a period of 10 min. The mixture was stirred at -78°C for 30 min, then 1,1,1- trifluoropropan-2-ol (3.92 g, 34.4 mmol, 1.5 eq) was added slowly. The reaction mixture was warmed to room temperature and stirred for 5 h. The reaction was quenched with water (100 mL), and the mixture was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the 4-bromo-2-fluoro-6-((1,1,1-trifluoropropan-2- yl)oxy)benzonitrile as a grey solid (5.1 g 71% yield).

Step B, Racemic 6-Bromo-4-((1,1,1- trifluoropropan-2-yl)oxy)- l H-indazol-3-amine. To a solution of 4-bromo-2-fluoro-6-((1,1,1-trifluoropropan-2-yl)oxy)benzonitrile (4.9 g, 15.7 mmol, 1.0 eq) in butan-1-ol (50 mL) was added hydrazine hydrate (4.72 g, 94.2 mmol, 6.0 eq). The resulting mixture was heated and stirred at 115 °C for overnight. The mixture was cooled to room temperature and quenched with water (100 mL). The resulting mixture was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by silica gel chromatography (0-30% ethyl acetate/petroleum ether) to afford the 6-bromo-4-(( 1,1,1- trifluoropropan-2-yl)oxy)-1H-indazol-3 -amine as a grey solid (3.6 g, 70.7% yield). LCMS: mass calcd. for C₁₀H₉BrF₃N₃O: 322.99, found 323.95 [M+H]⁺.

Step C. Racemic 6-Bromo- 1 -(4-methoxybenzyl)-4-((1,1,1- trifluoropropan-2-yl)oxy)- 1 H- indazol-3 -amine. To a solution of 6-bromo-4-(( 1,1,1 -trifluoropropan-2-y l)oxy)-1H- indazol-3-amine (2.1 g, 6.48 mmol, 1.0 eq) in DMSO (20 mL) was added 1- (chloromethyl)-4-methoxybenzene (1.22 g, 7.8 mmol, 1.2 eq), KOH (0.73 g, 13.0 mmol, 2.0 eq). The reaction mixture was stirred at room temperature for 4 h. The reaction was quenched with water (100 mL). The resulting mixture was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the 6-bromo-1-(4-methoxybenzyl)-4-(( 1,1,1- trifluoropropan-2-yl)oxy)-1H-indazol-3 -amine as a grey solid (2.0 g 69.5% yield). LCMS: mass calcd. for C₁₈H₁₇BrF₃N₃O₂: 443.05, found 444.05 [M+H]⁺.

Intermediate 4: 5-Bromo-7-methoxy-1H-indazole.

To a solution of 4-bromo-2-methoxy-6-methylaniline (5 g, 23.1 mmol, 1.0 eq) in glacial acetic acid (50 mL) at 0 °C was slowly added aqueous sodium nitrite solution (3.19 g, 46.3 mmol, 2.0 eq). The resulting reaction mixture was stirred at room temperature for overnight. The reaction was quenched with water (100 mL). The resulting mixture was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by silica gel chromatography (0-50 % ethyl acetate / petroleum ether) to afford the 5-bromo-7- methoxy-1H-indazole as a red solid (1.5 g, 28.5 % yield).

Intermediate 5: Racemic 5-Bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)- l H-indazole.

Step A, Racemic 5-Bromo-1-methyl-2-nitro-3-((1,1,1-trifluoropropan-2-yl)oxy)benzene. To a solution of 5-bromo-1-fluoro-3-methyl-2-nitrobenzene (3.6 g, 15 mmol) and 1,1,1- trifluoropropan-2-ol (2.6 g, 23 mmol) in THF (50 mL) at 0 °C was slowly added NaH (60%, 1.2 g, 32 mmol). The reaction mixture was stirred at room temperature for 0.5 h. The mixture was poured into saturated aqueous NH4CI solution (100 mL), and then extracted with ethyl ether (100 mL) and ethyl acetate (100 mL). The combined organic extract was dried over anhydrous MgSO₄, filtered, and concentrated. The residue was purified by silica gel chromatography (30% EtOAc in heptane) to afford the title compound as a yellow oil (5 g, 99% yield). LCMS (ES-API): mass calcd. for C₁₀H₉BrF₃NO₃, 327.0; m/z found, 328.0 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ7.15 (s, 1H), 7.09 (s, 1H), 4.66 (td, J= 6.25, 12.25 Hz, 1H), 2.30 (s, 3H), 1.52 (d, J= 6.06 Hz, 3H) ppm.

Step B, Racemic 4-Bromo-2-methyl-6-((1,1,1- trifluoropropan-2-yl)oxy)aniline. To a mixture of racemic 5-bromo-1-methyl-2-nitro-3-((1,1,1-trifluoropropan-2-yl)oxy)benzene (3 g, 9 mmol) in methanol (60 mL) was added an aqueous solution (18 mL) of NH4CI (2.4 g, 44 mmol) and zinc (3.6 g, 55 mmol) respectively. The reaction mixture was stirred at room temperature for 1 h. The mixture was filtered through a short pad of Celite®. The filtrate was concentrated to a small volume, then partitioned between ethyl acetate and water. The organic layer was separated, and the aqueous phase was extracted with ethyl acetate. The combined organic extract was washed with brine, dried over anhydrous

Na2SO₄, and concentrated to afford the crude product as a colorless oil (2.5 g, 92% yield), which was used crude in the next step without further purification. LCMS (ES-API): mass calcd. for CioHiiBrF₃NO, 297.0; m/z found, 298.0 [M+H]⁺. ¹H NMR (400 MHz, CDCh) δ 6.93 (s, 1H), 6.85 (s, 1H), 4.57 (td, J= 6.13, 12.51 Hz, 1H), 3.76 (br s, 2H), 2.15 (s, 3H),

1.52 (d, J = 6.57 Hz, 3H) ppm. Step C. Racemic 5-Bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)- l H-indazole. To a solution of racemic 4-bromo-2-methyl-6-((1,1,1-trifluoropropan-2-yl)oxy)aniline (4 g, 13 mmol) in aqueous HCl solution (37%, 6 mL) at 0 °C was slowly added aqueous solution (20 mL) of sodium nitrite (1.9 g, 27 mmol) over a period of 0.5 h. The resulting reaction mixture was stirred at 0 °C for 0.5 h, and then a pre-cooled aqueous solution (20 mL) of NaBF₄ (2.9 g, 27 mmol) was added. The reaction mixture was stirred at 0 °C for 40 min. The mixture was warmed to room temperature and extracted with ethyl acetate (2 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated.

The yellow foam was dissolved into chloroform (20 mL), and sodium acetate (3.3 g, 40 mmol) was added. The reaction mixture was stirred at room temperature for 4 h. The reaction was quenched by water (100 mL), and the mixture was extracted with ethyl acetate (100 mL). The organic layer was separated, dried over MgSO₄, filtered, and concentrated. The residue was purified by ISCO chromatography (SiO₂, 80 g, 0-50 % ethyl acetate in heptane) to afford the title compound as an off white solid (1.8 g, 43% yield). LCMS (ES-API): mass calcd. for C₁₀H₈BrF₃N₂O, 308.0; m/z found, 309.0 [M+H]⁺. Ή NMR (400 MHz, DMSO-d₆) δ 13.56 (br s, 1H), 8.05 (s, 1H), 7.65 (s, 1H), 7.31 (s, 1H),

5.58 (td, J= 6.32, 12.63 Hz, 1H), 1.52 (d, J= 6.06 Hz, 3H) ppm.

Intermediate 6: Racemic 1 -Benzyl-4-((5-bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)indolin- 1 -yl)methyl )pyridin-2( 1 H )-one.

Step A. Methyl 1 -benzyl-2-oxo- 1.2-dihydropyridine-4-carboxylate. To a solution of methyl 1,2-dihydro-2-oxopyridine-4-carboxylate (5 g, 33 mmol) in DMF (100 mL) at 0 °C was added K₂CO₃ (9 g, 65 mmol), followed by the addition of benzyl bromide (4.7 mL, 39 mmol) dropwise. The reaction mixture was stirred at room temperature for overnight. Then water was added and the mixture was extracted with ethyl acetate. The combined organic extract was washed with saturated aqueous NH4CI solution, dried over anhydrous Na₂SO₄, filtered, and concentrated. The residue was purified by silica column chromatography (gradient elution: 0 - 60% EtOAc in petroleum ether) to give the title compound as a white solid (2.9 g, yield: 37%). MS (ESI): mass calcd. for C₁₄H₁₃NO₃, 243.1; m/z found, 244.1 [M+H]⁺;¹H NMR (400 MHz, DMSO-d₆) δ 7.95 (d, J= 6.9 Hz, 1 H), 7.31 - 7.37 (m, 2 H), 7.27 - 7.30 (m, 3 H), 6.91 (d, J= 1.7 Hz, 1 H), 6.60 (dd, J= 6.9, 1.8 Hz, 1 H), 5.14 (s, 2 H), 3.84 (s, 3 H) ppm.

Step B, 1-Benzyl-4-(hydroxymethyl)pyridin-2(1Hl-one. To a solution of methyl 1 -benzyl- 2-oxo- 1,2-dihydropyridine-4-carboxylate (2 g, 8.2 mmol) in THF (80 mL) under nitrogen at 0 °C was added L1BH4 (269 mg, 12.3 mmol). The reaction mixture was warmed to room temperature and stirred for overnight. The reaction was quenched by the addition of saturated aqueous NH4CI solution, and the mixture was extracted with ethyl acetate. The combined organic layer was dried over anhydrous Na₂SO₄, filtered, and concentrated to give the crude title compound as a white solid (2 g, 100%). MS (ESI): mass calcd. for C₁₃H₁₃NO₂, 215.1; m/z found, 216.1 [M+H]⁺;¹H NMR (400 MHz, CDCl₃) δ 7.22 - 7.34 (m, 5 H), 7.22 (d, J= 7.1 Hz, 1 H), 6.63 (d, J= 0.7 Hz, 1 H), 6.14 (dd, J= 7.1, 1.7 Hz, 1 H), 5.12 (s, 2 H), 4.51 (s, 2 H), 2.83 (s, 1 H) ppm.

Step C. 1-Benzy1-4-(bromomethyl)pyridin-2(1Hl-one. To a solution of l-benzyl-4- (hydroxymethyl)pyridin-2(1H)-one (1 g, 4.4 mmol) in CHCl₃ (40 mL) was added POBn (2.5 g, 8.8 mmol). The reaction mixture was stirred at room temperature for overnight. The solvent was evaporated, and water was added. The mixture was adjusted to “pH” 7 - 8 by aqueous NaOH solution (5 M), and then extracted with ethyl acetate. The combined organic layer was dried over anhydrous Na₂SO₄, filtered, and concentrated. The residue was purified by silica column chromatography (gradient elution: 0 - 70% EtOAc in petroleum ether) to give the title compound as a white solid (530 mg, yield: 43%). MS (ESI): mass calcd. for C₁₃H₁₂BrNO, 277.0; m/z found, 278.0 [M+H]⁺;¹H NMR (400 MHz, CDCl₃) δ 7.28 - 7.39 (m, 5 H), 7.25 (d, J= 7.1 Hz, 1 H), 6.60 (d, J= 1.4 Hz, 1 H), 6.19 (dd, J= 7.1, 1.9 Hz, 1 H), 5.13 (s, 2 H), 4.20 (s, 2 H) ppm.

Step D. Racemic 1 -Benzyl-4-((5-bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)indolin-1- yl)methyl)pyridin-2(1H)-one. To a mixture of racemic 5-bromo-7-((1,1,1-trifluoropropan- 2-yl)oxy)indoline (Intermediate 2, 316 mg, 1.0 mmol) and K₂CO₃ (402 mg, 2.9 mmol) in N,N-dimethylformamide (12 mL) was added l-benzyl-4-(bromomethyl)pyridin-2(1H)-one (539 mg, 1.9 mmol). The resulting reaction mixture was stirred at 80 °C for 4 h. The mixture was cooled to room temperature, filtered through a short pad of Celite®. The filtrate was concentrated. The residue was purified by silica gel chromatography (0-70 % ethyl acetate / petroleum ether) to afford the title compound as a white solid (490 mg, yield: 91%). MS (ESI): mass calcd. for C₂₄H₂₂BrF₃N₂O₂, 506.1; m/z found, 507.1 [M+H]⁺;¹H NMR (400 MHz, CDCl₃) δ 7.28 - 7.34 (m, 3 H), 7.22 - 7.27 (m, 2 H), 7.17 (d, J= 7.1 Hz, 1 H), 6.88 - 6.90 (m, 1 H), 6.74 (d, J= 1.2 Hz, 1 H), 6.52 (d, J= 0.9 Hz, 1 H), 6.11 (dd, J= 6.9, 1.8 Hz, 1 H), 5.10 (d, J= 1.2 Hz, 2 H), 4.55 (spt, J= 6.3 Hz, 1 H), 4.27 - 4.46 (m, 2 H), 3.23 - 3.38 (m, 2 H), 2.91 - 2.98 (m, 2 H), 1.38 (d, J= 6.4 Hz, 3 H); ¹⁹F

NMR (376 MHz, CDCl₃) δ -78.61 (d, J= 5.9 Hz, 3 F) ppm.

Intermediate 7: Racemic (5-Bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-1-yl)(2- chloro-6-fluorophenyl)methanone.

To a solution of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)indoline (Intermediate 2, 250 mg, 0.8 mmol), 2-chloro-1-methylpyridinium iodide (330 mg, 1.3 mmol) and Et₃N (196 mg, 1.9 mmol) in DCM (7 mL) at room temperature was added 2- chloro-6-fluorobenzoic acid (225 mg, 1.3 mmol). The reaction mixture was stirred at 80 °C for 2 h. Another batch of racemic 2-(1-bromoethyl)-1-chloro-3-fluorobenzene (728 mg, 3.1 mmol) was added. The reaction mixture was heated at 50 °C for 16 h. Water was added and the resulting mixture was extracted with ethyl acetate. The organic layer was separated, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by silica gel chromatography (0-11% ethyl acetate/petroleum ether) to afford the title compound as a colorless oil (236 mg, yield: 63%). MS (ESI): mass calcd. for C₁₈H₁₃BrClF₄NO₂, 465.0; m/z found, 466.0 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.20 - 7.35 (m, 1 H), 6.94 - 7.19 (m, 3 H), 6.60 - 6.93 (m, 1 H), 4.40 - 4.74 (m, 1 H), 4.11 - 4.33 (m, 1 H), 3.79 (d, J= 7.6 Hz, 1 H), 2.84 - 3.21 (m, 2 H), 1.10 - 1.27 (m, 3 H); ¹⁹F NMR (376 MHz, CDCl₃) δ -78.65 - -77.37 (m, 1 F), -113.88 - -110.42 (m, 1 F) ppm. Intermediate 8: Racemic 5-Bromo-4-fluoro-7-((1,1,1- trifluoropropan-2-yl)oxy)-1H-indole.

Step A, Racemic 1 -Bromo-2-fluoro-4-nitro-5-((1,1,1- trifluoropropan-2-yl)oxy)benzene. To a suspension of NaH (60%, 576 mg, 14.4 mmol) in THF (15 mL) under nitrogen at 0 °C was added racemic 1,1,1-trifluoro-2-propanol (1.4 g, 12 mmol) drop wise. The mixture was stirred at room temperature for 0.5 hour, followed by the addition of a solution of 1-bromo- 2,5-difluoro-4-nitrobenzene (2 g, 8.4 mmol) in THF (15 mL). The reaction mixture was stirred under nitrogen at room temperature for overnight. Ice-water was added to quench the reaction, and the mixture was extracted with EtOAc. The combined organic layers were dried over Na₂SO₄ and concentrated. The residue was purified by silica column chromatography (gradient elution: 0 - 10% EtOAc in petroleum ether) to give the title compound as a yellow oil (1.3 g, yield: 67%). ¹H NMR (400 MHz, DMSO-d₆) δ 8.11 (d, J = 8.1 Hz, 1 H), 8.05 (d, J= 5.6 Hz, 1 H), 5.50 (spt, J= 6.4 Hz, 1 H), 1.42 (d, J = 6.4 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.76 (d, J = 6.6 Hz, 1 F), -113.23 (t, J = 6.6 Hz, 1 F) ppm. Step B, Racemic 5-Bromo-4-fluoro-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole. To a solution of racemic 1-bromo-2-fluoro-4-nitro-5-((1,1,1-trifluoropropan-2-yl)oxy)benzene (11.3 g, 3.9 mmol) in THF (20 mL) at -40 °C was added a THF solution (1 M) of vinylmagnesium bromide in (19.6 mL, 19.6 mmol) over a period of 20 min. The resulting reaction mixture was warmed to room temperature and stirred for 4 h. The reaction was quenched with sat. aqueous NH₄CI (200 mL). The mixture was extracted with ethyl acetate. The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue obtained was purified by silica gel chromatography (0-10% ethyl acetate/petroleum ether) to afford the title compound as a yellow oil (320 mg, yield: 25%). ¹H NMR (400 MHz, DMSO-d₆) δ 11.72 (br s, 1 H), 7.38 (t, J = 2.7 Hz, 1 H), 7.12 (d, J = 4.9 Hz, 1 H), 6.51 - 6.55 (m, 1 H), 5.37 - 5.47 (m, 1 H), 1.48 (d, J = 6.4 Hz, 3 H); 1⁹F NMR (376 MHz, DMSO- d₆) δ -77.36 (br d, J = 6.6 Hz, 1 F), -124.94 - -124.72 (m, 1 F) ppm.

Intermediate 9: 5-Bromo-7-isopropoxy-1H-indole.

Step A, 4-Bromo-2-isopropoxy-1-nitrobenzene. To a suspension of NaH (60%, 1.5 g, 36.4 mmol) in THF (100 mL) under nitrogen at 0 °C was added i-PrOH (2.6 mL, 34.1 mmol) dropwise. The mixture was stirred at room temperature for 0.5 hour, followed by the addition of 4-bromo-2-fluoro-1-nitrobenzene (5 g, 22.7 mmol). The reaction mixture was stirred under nitrogen at room temperature for 0.5 h. Ice- water was added to quench the reaction, and the mixture was extracted with EtOAc. The combined organic layers were dried over Na₂SO₄ and concentrated. The residue was purified by silica column chromatography (gradient elution: 0 - 1% EtOAc in petroleum ether) to give the title compound as a yellow oil (5.1 g, yield: 87%). ¹H NMR (400 MHz, CDCl₃) δ 7.69 (d, J = 8.6 Hz, 1 H), 7.23 (s, 1 H), 7.14 (dd, J= 8.6, 1.7 Hz, 1 H), 4.67 (dquin, J= 12.1, 6.0 Hz, 1 H), 1.42 (s, 3 H), 1.41 (s, 3 H) ppm. Step B, 5-Bromo-7-isopropoxy-1H-indole. To a solution of 4-bromo-2-isopropoxy-1- nitrobenzene (7.2 g, 27.7 mmol) in THF (20 mL) at -40 °C was added a THF solution (1 M) of vinylmagnesium bromide in (139 mL, 138.6 mmol) over a period of 20 min. The resulting reaction mixture was warmed to room temperature and stirred for 4 h. The reaction was quenched with sat. aqueous NH₄CI (200 mL). The mixture was extracted with ethyl acetate. The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue obtained was purified by silica gel chromatography (0-5% ethyl acetate/petroleum ether) to afford the title compound as a brown solid (1.2 g, yield: 17%). MS(ESI): mass calcd. for C₁₁H₁₂BrNO: 253.0, found 254.0 [M+H]⁺. ¹H ¹H NMR (400 MHz, CDCl₃) δ 8.44 (br s, 1 H), 7.40 (d, J= 1.0 Hz, 1 H), 7.16 (t, J= 2.7 Hz, 1 H), 6.78 (d, J= 1.2 Hz, 1 H), 6.45 - 6.50 (m, 1 H), 4.71 (spt, J= 6.0 Hz, 1 H), 1.43 (d, J = 6.1 Hz, 6 H) ppm.

Intermediate 10: 5-(^'(^'(^'tert-Butyldiphenylsilyl)oxy)niethyl)-4-ethyl-2.4-dihydro-3H-1.2.4- triazol-3-one.

Step A, 2-(Benzyloxy)acetohydrazide. To a solution of ethyl 2-(benzyloxy)acetate (55 g, 283.17 mmol) in EtOH (500 mL) was added NH₂NH₂·H₂O (28.3 g, 566 mmol, 27.5 mL).

The mixture was heated reflux at 78 °C stirred for 6 h. The reaction mixture was concentrated under reduced pressure to get the title product (52 g, crude) was obtained as a colorless oil, which was used directly to next step without further purification.

Step B, 3-((Benzyloxy)methyl)-4-ethyl- 1 H- 1 ,2.4-triazol-5(4H)-one. To a solution of 2- (benzyloxy)acetohydrazide (52 g, 288 mmol) in H₂O (500 mL) was added dropwise isocyanatoethane (25.1 g, 346 mmol, 27.9 mL) at 0 °C. After addition, the mixture was stirred at 25°C for 12 hr. To the mixture was added H₂O (20 mL), and an aqueous solution (120 mL) of NaOH (57.7 g, 1.44 mol). The mixture was stirred at 95 °C for 12 hr. The reaction mixture was quenched with HCl (12 M) at 0 °C and adjusted to “pH” 6. The solid was filtered and dried under reduced pressure to get the title product as a white solid (61 g, 261 mmol, 91% yield). ¹H NMR (400MHz, CDCl₃) δ = 9.23 - 9.09 (m, 1H), 7.41 - 7.31 (m, 5H), 4.58 - 4.53 (m, 2H), 4.45 - 4.42 (m, 2H), 3.82 - 3.75 (m, 2H), 1.33 - 1.29 (m, 3H). Step C. 4-Ethyl-5-(hydroxyniethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one. To a solution of 5- [(benzyloxy)methyl]-4-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (8 g, 34.3 mmol, 1.0 eq.) in methanol (200 mL) was added Pd/C (2 g). The resulting mixture was maintained under hydrogen and stirred at rt for 6 h. Then the resulting mixture was filtered and the filtrate was concentrated to afford the crude product 4-ethyl-5-(hydroxymethyl)-2,4- dihydro-3H-1,2,4-triazol-3-one as a white solid (4.3 g, 88 % yield). ¹H NMR (400 MHz, DMSO-d₆) δ 11.52 (s, 1H), 5.55 (t, J= 5.50 Hz, 1H), 4.32 (d, J= 5.50 Hz, 2H), 3.64 (q, J = 6.97 Hz, 2H), 1.18 (t, J= 6.97 Hz, 3H)

Step D. 5-(((tert-Butyldiphenylsilyl)oxy)niethyl)-4-ethyl-2.4-dihydro-3H- 1.2.4-triazol-3- one.

To a solution of 4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (3 g, 21 mmol, 1.0 eq.) in DCM (30 mL) was added tert-butylchlorodiphenylsilane (6.5 mL, 25 mmol, 1.2 eq.) and pyridine (1.86 mL, 23 mmol, 1.1 eq.). The resulting mixture was stirred at rt for overnight. The reaction mixture was quenched with water (100 mL). The resulting mixture was extracted with DCM (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel chromatography (50-80 % ethyl acetate / petroleum ether) to afford the title compound as a white solid (4.9 g, 61 % yield). LCMS (ES-API): mass calcd. for C₂₁H₂₇N₃O₂Si, 381.2; m/z found, 382.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 9.98 (s, 1H), 7.61-7.72 (m, 4H), 7.32-7.54 (m, 6H), 4.54 (s, 2H), 3.84 (q, J= 7.34 Hz, 2H), 1.33 (t, J= 7.34 Hz, 3H), 1.07 (s, 9H) ppm.

Example 1 : (R*l-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one.

Step A. Racemic 5-Bromo-1-(2-chloro-6-fluorobenzyl)-7-((1,1,1- trifluoropropan-2- yl)oxy)-1H-indole. To a solution of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)- 1H- indole (Intermediate 1, 2.0 g, 6.49 mmol, 1.0 eq) in DMF (20 mL) was added 2- (bromomethyl)-1-chloro-3-fluorobenzene (1.74 g, 7.79 mmol, 1.2 eq.), K₂CO₃ (2.69 g,

19.5 mmol, 3.0 eq.). The reaction was stirred at 80 °C for 4 h. After cooling to r.t, the reaction was quenched with water (100 mL). The resulting mixture was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue obtained was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the title compound as a yellow solid (1.8 g, 62.4% yield). LCMS: mass calcd. for C₁₈H₁₇BrF₃N₃O₂: 448.98, found 451.90 [M+H]⁺.

Step B: Racemic 5-(((tert-Butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6-fluorobenzyl)- 7-((1,1,1-trifluoropropan-2-yl)oxy)- 1 H-indol- 5-yl)-4-ethyl-2.4-dihydro-3H- 1 ,2.4-triazol-3 - one. To a solution of racemic 5-bromo-1-(2-chloro-6-fluorobenzyl)-7-((1,1,1- trifluoropropan-2-yl)oxy)-1H-indole (300 mg, 0.67 mmol, 1.0 eq.) in 1,4-dioxane (8 mL) were added 5-(((tert-butyldiphenylsilyl)oxy)methyl)-4-ethyl-2,4-dihydro-3H-1,2,4-triazol- 3 -one (Intermediate 10, 304.8 mg, 0.8 mmol, 1.2 eq.), Cul (63.7mg, 0.33 mmol, 0.5 eq.), KI (77.4 mg, 0.47 mmol, 0.7 eq.), cesium carbonate (390.4 mg, 1.2 mmol, 1.8 eq.) and (1R,2R)-(-)-1,2-Diaminocyclohexane (45.6 mg, 0.4 mmol, 0.6 eq.). The reaction mixture was stirred under nitrogen at 80 °C for overnight. The reaction was quenched with water and the mixture was extracted with ethyl acetate. The combined organic layer was washed with brine, dried over Na₂SO₄ and concentrated. The residue obtained was purified by silica gel chromatography (0-20% EtOAc/petroleum ether) to afford 5-(((tert- butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6-fluorobenzyl)-7-((1,1,1 -trifluoropropan- 2-yl)oxy)-1H-indol-5-yl)-4-ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one as a white solid (370 mg, 81.4% yield).

Step C. (R* )-2-( 1 -(2-Chloro-6-fluorobenzyl)-7-(( 1.1.1 -trifluoropropan-2-yl)oxy)- l H-indol- 5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-1.2.4-triazol-3-one. To a solution of 5- (((tert-butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6-fluorobenzyl)-7-methoxy-1H- indazol-5-yl)-4-ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one (200 mg, 0.298 mmol, 1.0 eq.) in tetrahydrofuran (5 mL), was added triethylammonium fluoride (240.5 mg, 1.49 mmol, 5.0 eq.). The reaction mixture was stirred at 60 °C for 4 h. The mixture was concentrated. The residue was purified by reverse phase HPLC [C18 (0-90% H₂O/CH₃CN)] to afford 2-(1-(2- chloro-6-fluorobenzyl)-7-((1,1,1 -trifluoropropan-2-yl)oxy)- 1 H-indol-5-yl)-4-ethyl-5-

(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (150 mg). The product was separated by Chiral-SFC to afford the title compound (front peak) as a white solid (58.1 mg, 39%) and (S*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (Example 2) (150 mg) as a white solid (58.6 mg, 39% yield). LCMS: mass calcd. for C₂₃H₂₁CIF₄N₄O₃: 512.88, found: 513.10 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.74 (d, J= 1.7 Hz, 1H), 7.46 (d, J = 1.7 Hz, 1H), 7.36 - 7.24 (m, 2H), 7.07 (ddd, J= 9.3, 7.5, 1.9 Hz, 1H), 6.80 (d, J= 3.2 Hz, 1H), 6.45 (d, J= 3.2 Hz, 1H), 5.94 (dd, J= 14.2, 1.9 Hz, 1H), 5.80 (dd, J= 14.2, 1.8 Hz, 1H), 5.05 (hept, J= 6.3 Hz, 1H), 4.66 (s, 2H), 3.89 (q, J= 7.2 Hz, 2H), 2.02 (br s, 1H), 1.67 (d, J= 6.4 Hz, 3H), 1.41 (t, J= 7.2 Hz, 3H); ¹⁹F NMR (376 MHz, CDCl₃) δ -78.50

(3F), -112.86 (IF) ppm.

Example 2: (S* )-2-( \ -(2-Chloro-6-fluorobenzyl)-7-(( 1.1.1 -trifluoropropan-2-yl)oxy)- 1 H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-E2.4-triazol-3-one.

The title compound was isolated after Chiral- SFC separation of Example 1, Step C. LC/MS: mass calcd. for C₂₃H₂₁CIF₄N₄O₃: 512.12, found: 513.10 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.74 (d, J= 1.7 Hz, 1H), 7.46 (d, J= 1.8 Hz, 1H), 7.36 - 7.24 (m, 2H), 7.07 (td, J= 8.0, 7.2, 1.8 Hz, 1H), 6.80 (d, J= 3.2 Hz, 1H), 6.45 (d, J= 3.1 Hz, 1H), 5.94 (dd, J= 14.2, 1.9 Hz, 1H), 5.80 (dd, J= 14.2, 1.8 Hz, 1H), 5.05 (p, J= 6.3 Hz, 1H), 4.67 (s, 2H), 3.90 (q, J= 7.2 Hz, 2H), 2.02 (br s, 1H), 1.67 (d, J= 6.4 Hz, 3H), 1.41 (t, J= 7.2 Hz, 3H), 1.27 (s, 1H); ¹⁹F NMR (376 MHz, CDCl₃) δ -78.50 (3F), -112.86 (IF) ppm.

Example 3: Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2- vl)oxy)indolin-5-vl)-4-ethvl-5-(hvdroxvmethvl)-2,4-dihvdro-3H-1,2,4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1, Steps A-C, using 5- bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)indoline (Intermediate 2) instead of racemic 5- bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1) in Step A. LCMS: mass calcd. for C₂₃H₂₃CIF₄N₄O₃: 514.9, found: 515.20 [M+H]⁺; ¹H NMR (300 MHz,

DMSO-d₆) δ 7.41 (pd, J= 8.1, 3.8 Hz, 3H), 7.33 - 7.21 (m, 2H), 5.74 (t, J= 5.7 Hz, 1H), 5.24 (p, J= 6.4 Hz, 1H), 4.80 (dd, J= 13.0, 2.1 Hz, 1H), 4.72 (dd, J= 12.8, 2.0 Hz, 1H), 4.47 (d, J= 5.7 Hz, 2H), 3.77 (q, J= 7.1 Hz, 2H), 3.12 (t, J= 8.4 Hz, 2H), 2.86 (t, J= 8.5 Hz, 2H), 1.48 (d, J= 6.3 Hz, 3H), 1.27 (t, J= 7.1 Hz, 3H); ¹⁹F NMR (282 MHz, DMSO- d₆) δ -77.15(3F), -111.92 (IF) ppm.

Example 4 : (R* )-2-(3 -((2-Chloro-6-fluorophenyl)aminol-4-(( 1.1.1 -trifluoropropan-2-yl)oxy)-] H-indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-1.2.4-triazol-3-one.

Step A. Racemic 6-Bromo-N-(2-chloro-6-fluorophenyl)-1-(4-methoxybenzyl)-4-((1,1,1- trifluoropropan-2-yl)oxy)- 1 H-indazol-3 -amine. To a solution of racemic 6-bromo-1-(4- methoxybenzyl)-4-((1,1,1 -trifluoropropan-2-yl)oxy)-1H-indazol-3 -amine (Intermediate 3, 504 mg, 1.13 mmol, 1.0 eq) in anhydrous 1,4-dioxane (10 mL) was added 1-chloro-3- fluoro-2-iodobenzene (436 mg, 1.70 mmol, 1.5 eq), Cul (43.2 mg, 0.23 mmol, 0.2 eq), KI (94.1 mg, 0.57 mmol, 0.5 eq), (lR,2R)-cyclohexane-1, 2-diamine (51.8 mg, 0.45 mmol, 0.4 eq), cesium carbonate (738.7 mg, 2.23 mmol, 2.0 eq). The reaction was stirred under nitrogen at 110 °C for 16 h. After cooling down to room temperature, the reaction was quenched with water (50 mL). The resulting mixture was extracted with ethyl acetate (3 x 50 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the 6-bromo-N-(2-chloro-6-fluorophenyl)-1-(4- methoxybenzyl)-4-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indazol-3-amine as a grey solid (392 mg 60.4% yield). LCMS: mass calcd. for C₂₄H₁₉BrClF₄N₃O₂: 571.03, found 572.00 [M+H]⁺.

Step B, Racemic 5-(((tert-Butyldiphenylsilyl)oxy)methyl)-2-(3-((2-chloro-6- fluorophenyl)amino)- 1 -(4-methoxybenzyl)-4-(( 1,1.1 -trifluoropropan-2-yl )oxy)-1H- indazol-6-yl)-4-ethyl-2.4-dihydro-3H-1.2.4-triazol-3-one. To a solution of 6-bromo-N-(2- chloro-6-fluorophenyl)- 1 -(4-methoxybenzyl)-4-((1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indazol-3-amine (370.2 mg, 0.646 mmol, 1.0 eq) in anhydrous 1,4-dioxane (10 mL) was added 5-(((tert-butyldiphenylsilyl)oxy)methyl)-4-ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one (369.9 mg, 0.969 mmol, 1.5 eq), Cul (24.6 mg, 0.129 mmol, 0.2 eq), KI (53.6 mg, 0.323 mmol, 0.5 eq), (lR,2R)-cyclohexane-1, 2-diamine (29.5 mg, 0.259 mmol, 0.4 eq), cesium carbonate (421.2 mg, 1.29 mmol, 2.0 eq). The reaction was stirred under nitrogen at 110 °C for 16 h. After cooling down to room temperature, the reaction was quenched with water (50 mL). The resulting mixture was extracted with ethyl acetate (3 x 50 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the 5-(((tert-butyldiphenylsilyl)oxy)methyl)-2-(3-((2-chloro-6-fluorophenyl)amino)- 1 -(4-methoxybenzyl)-4-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H-indazol-6-yl)-4-ethy 1-2,4- dihydro-3H-1,2,4-triazol-3-one as a grey solid (426.3 mg 75.5% yield). LCMS: mass calcd. for C45H45CIF₄N6O₄S1: 872.29, found 873.40 [M+H]⁺.

Step C. Racemic (1 -(3-((2-Chloro-6-fluoroDhenyl)amino)-4-((1,1,1- trifluoropropan-2- yl)oxy)- 1 H-indazol-6-yl)-4-ethyl-5-oxo-4.5-dihydro-1H-1.2.4-triazol-3-yl)methyl 2.2.2- trifluoroacetate. To a solution of 5-(((tert-butyldiphenylsilyl)oxy)methyl)-2-(3-((2-chloro- 6-fluorophenyl)amino)-1-(4-methoxybenzyl)-4-((1,1,1 -trifluoropropan-2-yl)oxy)- 1H- indazol-6-yl)-4-ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one (401.6 mg, 0.460 mmol, 1.0 eq) was added TFA (10 mL). The reaction was stirred at 50 °C fori 6 h. TLC (petroleum ether: ethyl acetate=5: 1) showed the reaction was completed. The reaction was quenched with water (50 mL). The resulting mixture was extracted with ethyl acetate (3 x 50 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue obtained was purified by silica gel chromatography (0-20% ethyl acetate/petroleum ether) to afford the (1-(3-((2-chloro-6-fluorophenyl)amino)-4-((1,1,1- trifluoropropan-2-yl)oxy)- 1 H-indazol-6-yl)-4-ethy 1-5 -oxo-4, 5 -dihydro- 1 H- 1 ,2,4-triazol-3 - yl)methyl 2,2,2-trifluoroacetate as a grey solid (163.6 mg, 58.2% yield).

Step D. (R* )-2-(3 -(( 2-Chloro-6-fluorophenyl)aminol-4-((1,1,1-trifluoropropan-2-yl)oxy)- 1H-indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-1.2.4-triazol-3-one. To a solution of (1-(3-((2-chloro-6-fluorophenyl)amino)-4-((1,1,1-trifluoropropan-2-yl)oxy)- 1H-indazol-6-yl)-4-ethyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl 2,2,2- trifluoroacetate (150.6 mg, 0.247 mmol, 1.0 eq) in methanol (5 mL) was added K₂CO₃ (102.2 mg, 0.740 mmol, 3.0 eq). The reaction mixture was stirred at 70 °C for 3 h. The mixture was diluted with water and extracted with EA. The combined extract was washed with water, dried over Na₂SO₄, filtered, and purified by pre-HPLC with MeCN/FLO (0- 30%) to give the racemic product. The product was chiral and separated by Prep-Chiral- HPLC separation [Gilson GX281, CHIRALPAK IF 25 cm x 25 cm x 5 μm column, (eluent: 20% to 20% (v/v) EtOH and Hex with 8mmol/L NH₃.MeOH)]. The collected fractions were combined and concentrated to afford (R)-2-(3-((2-chloro-6- fluorophenyl)amino)-4-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indazol-6-yl)-4-ethyl-5- (hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one as a grey solid (26.9 mg, 21.2% yield). LCMS: mass calcd. for C₂₁H₁₉CIF₄N₆O₃: 514.11, found 515.05 [M+H]⁺. ¹HNMR (400 MHz, CD3OD) δ 7.68 (d, J= 1.3 Hz, 1H), 7.28 - 7.36 (m, 2H), 7.11 - 7.21 (m, 2H), 5.29 (p, J= 6.2 Hz, 1H), 4.65 (s, 2H), 3.93 (q, J= 7.2 Hz, 2H), 1.62 (d, J= 6.4 Hz, 3H), 1.41 (t, J= 7.2 Hz, 3H); ¹⁹F NMR (376 MHz, CD3OD) δ -80.14, -117.37. ppm.

Example 5 : (S * )-2-(3 -((2-Chl oro-6-fluorophenyl)amino )-4-(( 1.1.1 -trifluoropropan-2- ylioxyi- l H-indazol-6-yl)-4-ethyl-5-((hydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one.

The title compound was isolated by Chiral -HPLC [Gilson GX281, CHIRALPAK IF 25 cm x 25 cm x 5 μm column, (eluent: 20% to 20% (v/v) EtOH and Hex with 8mmol/L NH₃.MeOH)] of Example 4, Step C. LCMS: mass calcd. for C₂₁H₁₉CIF₄N₆O₃: 514.11, found 515.05 [M+H]⁺. ¹H NMR (400 MHz, CD₃OD) δ d 7.68 (d, J= 1.4 Hz, 1H), 7.28 - 7.36 (m, 2H), 7.11 - 7.21 (m, 2H), 5.29 (p, J= 6.3 Hz, 1H), 4.65 (s, 2H), 3.93 (q, J= 7.2 Hz, 2H), 1.62 (d, J = 6.4 Hz, 3H), 1.41 (t, J= 7.2 Hz, 3H); ¹⁹F NMR (376 MHz, CD3OD) d -80.14, -80.18, -117.38 ppm.

Example 6: 2-(1 -(2-Chloro-6-fluorobenzyl)-7-methoxy- 1 H-indazol-5-yl)-4-ethyl-5- (hydroxymethyl)-2.4-dihydro-3H-E2.4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1 , Steps A-C, except using 5-bromo-7-methoxy-1H-indazole (Intermediate 4) instead of racemic 5-bromo-7- ((1,1,1-trifluoropropan-2-yl)oxy)-1H- indole (Intermediate 1) in Step A. LCMS: mass calcd. for C₂₀H₁₉CIFN₅O₃: 431.85, found: 432.05 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.94 (s, 1H), 7.79 (d, J= 1.6 Hz, 1H), 7.52 (d, J= 1.6 Hz, 1H), 7.24 (dt, J= 8.0, 5.9 Hz, 2H), 7.03 (ddd, J = 9.4, 7.4, 2.1 Hz, 1H), 6.06 (d, J= 1.4 Hz, 2H), 4.68 (s, 2H), 4.05 (s, 3H), 3.91 (q, J= 7.2 Hz, 2H), 1.73 (br s, 1H), 1.42 (t, J= 7.2 Hz, 3H); ¹⁹F NMR (376 MHz, CDCl₃) δ -113.38 ppm.

Example 7: Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-

1 H-indazol-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1 , Steps A-C, except using racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indazole (Intermediate 5) instead of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1) in Step A. LCMS (ES-API): mass calcd. for C₂₂H₂₀CIF₄N₅O₃, 513.1; m/z found, 514.2 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 8.07 (s, 1H), 7.85 (d, J= 1.47 Hz, 1H), 7.65 (s, 1H), 7.40-7.50 (m, 1H), 7.34-7.41 (m, 1H), 7.27 (br t, J= 8.80 Hz, 1H), 5.91 (s, 2H), 5.79 (t, J= 5.62 Hz, 1H), 5.60 (td, J= 6.17, 12.59 Hz, 1H), 4.51 (d, J= 5.38 Hz, 2H), 3.80 (q, J = 7.34 Hz, 2H), 1.58 (d, J= 5.87 Hz, 2H), 1.29 (t, J= 7.09 Hz, 3H) ppm.

Example 8: Racemic 2-(1 -(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)-1H-indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-E2.4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1 , Steps A-C, except using racemic 2-(1-bromoethyl)-1-chloro-3-fluorobenzene instead of 2-(bromomethyl)-1- chloro-3-fluorobenzene in Step A. MS (ESI): mass calcd. for C24H₂3CIF₄N₄O₃, 526.1; m/z found, 527.2 [M+H]⁺; ¹H NMR (400 MHz, DMSO-d₆) δ 7.64 (t, J= 1.5 Hz, 1 H), 7.39 - 7.47 (m, 1 H), 7.32 - 7.38 (m, 2 H), 7.19 - 7.32 (m, 2 H), 6.62 - 6.76 (m, 1 H), 6.51 (t, J = 3.2 Hz, 1 H), 5.73 (t, J= 5.8 Hz, 1 H), 5.44 (dd, J= 11.1, 6.2 Hz, 1 H), 4.49 (d, J= 5.6 Hz, 2 H), 3.78 (q, J= 7.2 Hz, 2 H), 1.84 - 1.92 (m, 3 H), 1.56 (d, J= 6.4 Hz, 1.5 H), 1.41 (d, J = 6.1 Hz, 1.5 H), 1.27 (t, J= 7.2 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.04 (dd, J = 34.1, 6.2 Hz, 3 F), -110.99 (br s, 1 F) ppm.

Example 9: (R)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy))indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-E2.4-triazol-3-one.

Racemic 2-(1-(2-chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)- 4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (Example 3) was separated by chiral preparative SFC (Column: Phenomenex-Cellulose-2, 5 μm, 250 x 30 mm; Mobile phase: A: supercritical CO₂, B: MeOH (0.1% NH₃ H₂O), gradient elution: 25% B in A , flow rate: 60 mL/min) to give the title compound as a yellow solid (161 mg, 33%). SFC: purity 96% [retention time 4.43 min. analytical method: CELLULOSE_2_MEOH(DEA)_5_40_2, 5MF 10MIN] . LCMS: mass calcd. for C₂₃H₂₃CIF₄N₄O₃: 514.1, found: 515.2 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.34 - 7.47 (m, 3 H), 7.20 - 7.30 (m, 2 H), 5.72 (t, J= 5.9 Hz, 1 H), 5.23 (q, J= 6.4 Hz, 1 H), 4.67 - 4.83 (m, 2 H), 4.46 (d, J= 5.6 Hz, 2 H), 3.76 (q, J= 7.1 Hz, 2 H), 3.07 - 3.17 (m, 2 H),

2.79 - 2.91 (m, 2 H), 1.47 (d, J= 6.4 Hz, 3 H), 1.26 (t, J= 7.1 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.19 (d, J= 6.6 Hz, 3 F), -111.96 (s, 1 F) ppm.

Example 10: (S)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2- yl )oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-di hydro-3 H-1,2.4-triazol-3-one.

Racemic 2-(1-(2-chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)- 4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-l ,2,4-triazol-3-one (Example 3)

Column: Phenomenex-Cellulose-2, 5 μm, 250 x 30 mm; Mobile phase: A: supercritical CO₂, B: MeOH (0.1% NH₃ H₂O), gradient elution: 25% B in A , flow rate: 60 mL/min), the title compound was obtained as the second product: a yellow solid (102 mg, 21% yield). SFC: purity 100% [retention time 4.23 min. analytical method: CELLULOSE- 2_MEOH(DEA)_5_40_2,5ML_10MIN] . LCMS: mass calcd. for C₂₃H₂₃CIF₄N₄O₃: 514.1, found: 515.2 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.33 - 7.48 (m, 3 H), 7.20 - 7.31 (m, 1 H), 7.17 - 7.33 (m, 1 H), 5.72 (t, J= 5.9 Hz, 1 H), 5.12 - 5.32 (m, 1 H), 4.66 - 4.83 (m, 2 H), 4.46 (d, J= 5.9 Hz, 2 H), 3.76 (q, J= 7.1 Hz, 2 H), 3.04 - 3.17 (m, 2 H), 2.80 - 2.92 (m, 2 H), 1.47 (d, J= 6.4 Hz, 3 H), 1.26 (t, J= 7.2 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.19 (d, J= 5.9 Hz, 3 F), -111.96 (s, 1 F) ppm. Example 11: Racemic 2-(1 -(1 -(^'2-Chloro-6-fluorophenyl)ethyl)-7-((1,1,1- trifluoropropan-2- vl)oxy)indolin-5-vl)-4-ethvl-5-(hvdroxvmethvl)-2,4-dihvdro-3H-1,2,4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1 , Steps A-C, using Racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)indoline (Intermediate 2) instead of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1); and using racemic 2-(1-bromoethyl)-1-chloro-3-fluorobenzene instead of 2-(bromomethyl)- 1 - chloro-3-fluorobenzene in Step A. MS (ESI): mass calcd. for C₂₄H₂₅CIF₄N₄O₃, 528.2; m/z found, 529.2 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 7.29 - 7.43 (m, 3 H), 7.16 - 7.27 (m, 2 H), 6.09 (dd, J= 13.6, 7.0 Hz, 1 H), 5.72 (t, J= 5.6 Hz, 1 H), 5.22 - 5.35 (m, 1 H), 4.45 (d, J= 5.6 Hz, 2 H), 3.76 (q, J= 7.1 Hz, 2 H), 3.43 - 3.60 (m, 1 H), 2.86 - 3.03 (m, 2 H),

2.69 - 2.85 (m, 1 H), 1.41 - 1.54 (m, 6 H), 1.25 (t, J= 7.2 Hz, 3 H) ppm.

Example 12: Racemic l-Benzyl-4-((5-(4-ethyl-3-(hydroxymethyl)-5-oxo-4.5-dihydro-1H- 1 ,2.4-triazol- 1 -yl)-7-( (1.1.1 -trifluoropropan-2-yl)oxy)indolin- 1 -yl)methyl)pyridin-2( 1 H)- one.

The title compound was prepared in a manner analogous to Example 1, Steps B-C, except using racemic 1 -benzyl-4-((5-bromo-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)indolin- 1 - yl)methyl)pyridin-2(1H)-one (Intermediate 6) instead of racemic 5-bromo-1-(2-chloro-6- fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole in Step B. MS (ESI): mass calcd. for C₂₉H₃₀F₃N₅O₄: 569.2, found: 570.3 [M+H]⁺; ¹H NMR (300 MHz, CDCl₃) δ 7.28 - 7.42 (m, 7 H), 7.21 (d, J= 6.8 Hz, 1 H), 6.56 (s, 1 H), 6.22 (d, J= 6.8 Hz, 1 H), 5.13 (s, 2 H), 4.68 - 4.76 (m, 1 H), 4.63 (d, J= 5.4 Hz, 2 H), 4.30 - 4.46 (m, 2 H), 3.87 (d, J= 7.3 Hz, 2 H), 3.20 - 3.34 (m, 2 H), 2.95 - 3.04 (m, 2 H), 2.85 (s, 1 H), 1.45 (d, J= 6.4 Hz, 3 H), 1.38 (t, J= 7.1 Hz, 3 H); ¹⁹F NMR (376 MHz, CDCl₃) δ -78.61 (d, J= 5.9 Hz, 1 F) ppm.

Example 13: (R* )-2-( 1 -(2-Chloro-6-fluorobenzoyl )-7-((1,1,1-trifluoropropan-2- yl)oxy)indol in-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-1,2.4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1, Steps B-C, except using racemic (5-bromo-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)indolin- 1 -yl)(2-chloro-6- fluorophenyl)methanone (Intermediate 7) instead of racemic 5-bromo-1-(2-chloro-6- fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole in Step B. Preparative SFC (Stationary phase: Phenomenex-Amylose-1, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - EtOH (0.1% NH₃H₂O) (B), gradient elution: 35% B in A , flow rate: 50 mL/min) afforded the title compound as the first fraction: a white solid (32.1 mg, yield: 28%) and (S*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (Example 14) a white solid (34.8 mg, yield: 30%). SFC: purity 100% [retention time 1.68 mm, SFC analytical method:AD_50MM_ETOH(DEA)_5_40_25ML]. MS (ESI): mass calcd. for C₂₃H₂₁CIF₄N₄O₄, 528.1; m/z found, 529.0 [M+H]⁺; ¹H NMR (400 MHz, DMSO- d₆) δ 7.60 (s, 1 H), 7.49 (s, 2 H), 7.26 (s, 2 H), 5.51 (s, 1 H), 4.84 (s, 1 H), 4.49 (s, 3 H), 3.99 (s, 2 H), 3.79 (q, J= 7.0 Hz, 3 H), 1.29 (t, J= 7.1 Hz, 6 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.46 - -76.17 (m, 1 F), -114.65 - -111.02 (m, 1 F) ppm.

Example 14: (S*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one.

The title compound was isolated from racemic 2-(1-(2-chloro-6-fluorobenzoyl)-7-((1,1,1- trifluoropropan-2-yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4- triazol-3-one (Example 13) by preparative SFC (Stationary phase: Phenomenex-Amylose- 1, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - EtOH (0.1% NH₃H₂O) (B), gradient elution: 35% B in A , flow rate: 50 mL/min. SFC: purity 100% [retention time 2.08 mm, SFC analytical method: AD_50MM_ETOH(DEA)_5_40_25ML], MS (ESI): mass calcd. for C₂₃H₂₁CIF₄N₄O₄, 528.1; m/z found, 529.0 [M+H]⁺; Ή NMR (400 MHz, DMSO-d₆) δ 7.60 (s, 1 H), 7.49 (s, 2 H), 7.25 (s, 2 H), 5.51 (s, 1 H), 4.85 (s, 1 H), 4.49 (d, J= 5.8 Hz, 3 H), 4.00 (s, 2 H), 3.79 (q, J= 7.3 Hz, 3 H), 1.29 (t, J= 7.2 Hz, 6 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ ppm -77.35 - -76.46 (m, 1 F), -114.30 - -111.20 (m, 1 F) ppm. Example 15 : (R* )-2-( 1 -(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1.1.1 -trifluoropropan-2- ylioxyi- l H-indol-5-yl)-4-ethyl-5-((hydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1, Steps A-C, except using racemic 5-bromo-4-fluoro-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole

(Intermediate 8) instead of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1) in Step A. Preparative chiral SFC (Stationary phase: Phenomenex- Amylose-1, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - EtOH (0.1% NH₃H₂O) (B), gradient elution: 15% B in A , flow rate: 50 mL/min) to give the afforded the compound as the first fraction: a white solid (118.8 mg, yield: 40%) and (S*)-2-(1-(2- Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1 -trifluoropropan-2-yl)oxy)- 1H-indol-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (Example 16) a white solid (118.8 mg, yield: 40%). SFC: 99.8%ee [retention time 2.89 min, SFC analytical method: AD_3_EtOH_DEA_5_40_25MP. ] MS(ESI): mass calcd. for C₂₃H₂₀CIF₅N₄O₃: 530.1, found 531.0 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.41 - 7.53 (m, 2 H), 7.26 - 7.34 (m, 1 H), 6.99 - 7.05 (m, 2 H), 6.59 (d, J= 3.4 Hz, 1 H), 5.83 (d, J= 2.2 Hz, 2 H), 5.76 (t, J = 5.6 Hz, 1 H), 5.49 (dt, J= 12.8, 6.5 Hz, 1 H), 4.47 (d, J= 5.6 Hz, 2 H), 3.78 (q, J= 7.1 Hz, 2 H), 1.45 (d, J= 6.4 Hz, 3 H), 1.28 (t, J= 7.1 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO- d₆) δ ppm -77.44 (br d, J= 5.9 Hz, 1 F), -115.49 - -113.37 (m, 1 F), -136.89 (d, J= 5.1 Hz, 1 F) ppm.

Example 16: (S* )-2-(1 -(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2-yl)oxy)- 1 H-indol-5-yl )-4-ethyl-5-(hydroxymethyl )-2.4-dihydro-3 H- 1.2.4-triazol-3-one.

The title compound was isolated by preparative chiral SFC (Stationary phase: Phenomenex-Amylose-1, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - EtOH (0.1% NH₃H₂O) (B), gradient elution: 15% B in A , flow rate: 50 mL/min) from Example 15. SFC: 99.6%ee [retention time 3.12 min, SFC analytical method:

AD_3_EtOH_DEA_5_40_25ML. ] MS(ESI): mass calcd. for C₂₃H₂₀CIF₅N₄O₃: 530.1, found 531.0 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.41 - 7.53 (m, 2 H), 7.26 - 7.35 (m, 1 H), 6.99 - 7.06 (m, 2 H), 6.59 (d, J= 3.0 Hz, 1 H), 5.83 (s, 2 H), 5.76 (br t, J= 5.7 Hz, 1 H), 5.45 - 5.55 (m, 1 H), 4.47 (d, J= 5.5 Hz, 2 H), 3.78 (q, J= 6.9 Hz, 2 H), 1.45 (d, J= 6.3 Hz, 3 H), 1.28 (t, J= 7.0 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.40 (s, 1 F), -114.40 (br s, 1 F), -136.85 (br s, 1 F) ppm.

Example 17: Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-

2-yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one.

Step A: Racemic 5-(((tert-Butyldiphenylsilyl)oxy)methyl)-2-( 1 -(2-chloro-6-fluorobenzyl)- 4-fluoro-7-(( .1. 1 -trifluoropropan-2-yl)oxy)-1H-indol-5-yl)-4-ethyl-2.4-dihydro-3H-1.2.4- triazol-3-one. The title compound was prepared in a manner analogous to Example 1, Steps A-B, except using racemic 5-bromo-4-fluoro-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indole (Intermediate 8) instead of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)- 1H-indole (Intermediate 1) in Step A. MS(ESI): mass calcd. for C₃₉H₃₈ClF₅N₄O₃Si: 768.2, found 769.4 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.66 (d, J = 6.3 Hz, 4 H), 7.41 - 7.53 (m, 9 H), 7.26 - 7.35 (m, 1 H), 7.04 (s, 1 H), 6.60 (d, J = 2.5 Hz, 1 H), 5.46 (s, 1 H), 4.70 (s, 2 H), 3.84 (d, J = 8.0 Hz, 4 H), 1.46 (d, J = 6.0 Hz, 3 H), 1.29 - 1.34 (m, 3 H),

1.04 (s, 9 H); ¹⁹F NMR (377 MHz, DMSO-d₆) δ -77.37 (br s, 1 F), -114.62 - -114.29 (m, 1 F), -136.89 (br s, 1 F) ppm.

Step B: Racemic 5-(((tert-Butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6-fluorobenzyl)- 4-fluoro-7-((1.1.1 -trifluoropropan-2-yl)oxy)indolin-5-yl)-4-ethyl-2.4-dihydro-3H- 1.2.4- triazol-3-one. To a solution of racemic 5-(((tert-butyldiphenylsilyl)oxy)methyl)-2-(1-(2- chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-y l)oxy)- 1 H-indol-5 -yl)-4- ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one (600 mg, 0.8 mmol) in TFA (5.4 mL) at 0 °C was added Et3SiH (272 mg, 2.4 mmol). The reaction mixture was stirred at 0 °C for 3 h. The mixture was diluted with ethyl acetate and the “pH” was adjusted to 7-8 by saturated aqueous NaHCO₃ solution. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The combined organic extract washed with brine, dried over Na₂SO₄ and concentrated. The residue obtained was purified by silica gel chromatography (0-25% EtOAc/petroleum ether) to afford the title compound as a yellow oil (530 mg, yield: 88%). MS(ESI): mass calcd. for C₃₉H₄₀CIF₅N₄O₃S1: 770.3, found 771.4 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.57 - 7.65 (m, 4 H), 7.31 - 7.43 (m, 6 H), 7.13 - 7.17 (m, 2 H), 6.89 - 6.96 (m, 1 H), 6.67 (d, J = 5.9 Hz, 1 H), 4.95 (dd, J = 13.4, 2.0 Hz, 1 H), 4.71 (dd, J = 13.3, 1.6 Hz, 1 H), 4.56 - 4.62 (m, 1 H), 4.54 (s, 2 H), 3.80 - 3.89 (m, 2 H), 3.19 - 3.27 (m, 2 H), 2.79 - 2.97 (m, 2 H), 1.45 (d, J = 6.4 Hz, 3 H), 1.30 (t, J=1.2 Hz, 3 H), 1.02 (s, 9 H) ppm.

Step C. Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl )oxy)indol in-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-1.2.4-triazol-3-one. To a solution of racemic 5-(((tert-butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6- fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)indolin-5-yl)-4-ethy 1-2,4- dihydro-3H-1,2,4-triazol-3-one (530 mg, 0.69 mmol) in tetrahydrofuran (35 mL), was added Et3N.3HF (1.7 g, 10.3 mmol). The reaction mixture was stirred at 60 °C for 3 h. The mixture was concentrated. Water was added, and the mixture was extracted with ethyl acetate. The combined organic layers were dried over Na₂SO₄ and concentrated. The residue was purified by preparative reversed phase HPLC (Stationary phase: Boston Prime C18, 5 μm, 150 x 30 mm; Mobile phase: H₂O (0.04% NH₃H₂O + 10 mM NH4HCO₃) (A) - MeCN (B), gradient elution: 55 - 85% B in A over 8 min, flow rate: 25 mL/min) to give the title compound as a white solid (230 mg, yield: 63%). MS(ESI): mass calcd. for C₂₃H₂2CIF₅N₄O₃: 532.1, found 533.1 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.37 -

7.48 (m, 2 H), 7.24 - 7.31 (m, 1 H), 7.11 (d, J = 6.3 Hz, 1 H), 5.75 (t, J = 5.7 Hz, 1 H),

5.28 (dt, J = 13.1, 6.4 Hz, 1 H), 4.79 - 4.94 (m, 2 H), 4.44 (d, J = 5.8 Hz, 2 H), 3.76 (q, J = 7.2 Hz, 2 H), 3.26 (t, J = 9.0 Hz, 2 H), 2.89 - 2.95 (m, 2 H), 1.42 (d, J = 6.3 Hz, 3 H), 1.26 (t, J = 7.2 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ -77.28 (s, 1 F), -112.24 (s, 1 F), - 134.18 (s, 1 F) ppm.

Example 18: (S*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one.

Preparative chiral SFC (Stationary phase: DAICEF CHIRAFPAK AD-H, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - i-PrOH (0.1% NH₃H₂O) (B), gradient elution:

15% B in A , flow rate: 50 mF/min) of Example 17, afforded the title compound as the first fraction: a white solid (130 mg, yield: 39%). SFC: 99.6%ee [retention time 2.35 min, SFC analytical method: AD_ETOH(DEA)_5_40_2,8MF]. MS(ESI): mass calcd. for C₂₃H₂₂CIF₅N₄O₃: 532.1, found 533.0 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.37 -

7.48 (m, 2 H), 7.25 - 7.32 (m, 1 H), 7.11 (d, J = 6.3 Hz, 1 H), 5.73 (s, 1 H), 5.29 (dt, J = 12.9, 6.2 Hz, 1 H), 4.80 - 4.94 (m, 2 H), 4.44 (s, 2 H), 3.76 (q, J = 7.2 Hz, 2 H), 3.26 (t, J = 8.8 Hz, 2 H), 2.89 - 2.96 (m, 2 H), 1.42 (d, J = 6.5 Hz, 3 H), 1.26 (t, J = 7.0 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ ppm -77.29 (s, 1 F), -112.24 (s, 1 F), -134.19 (s, 1 F) ppm.

Example 19: (R*)-2-( 1 -(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one.

Preparative chiral SFC (Stationary phase: DAICEL CHIRALPAK AD-H, 5 μm, 250 x 30 mm; Mobile phase: supercritical CO₂ (A) - /-PrOH (0.1% NH₃H₂O) (B), gradient elution: 15% B in A , flow rate: 50 mL/min), of Example 17, afforded the title compound as the second fraction: a white solid (123 mg, yield: 37%). SFC: 97.2%ee [retention time 2.18 min, SFC analytical method: AD_ETOH(DEA)_5_40_2,8ML]. MS(ESI): mass calcd. for C₂₃H₂₂CIF₅N₄O₃: 532.1, found 533.0 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.37 - 7.48 (m, 2 H), 7.25 - 7.31 (m, 1 H), 7.11 (d, J = 6.0 Hz, 1 H), 5.74 (s, 1 H), 5.29 (dt, J = 12.9, 6.5 Hz, 1 H), 4.80 - 4.94 (m, 2 H), 4.44 (s, 2 H), 3.76 (q, J = 7.0 Hz, 2 H), 3.26 (t, J

= 8.8 Hz, 2 H), 2.89 - 2.96 (m, 2 H), 1.42 (d, J = 6.3 Hz, 3 H), 1.26 (t, J = 7.2 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ ppm -77.33 - -77.25 (m, 1 F), -112.24 (s, 1 F), -134.19 (s, 1 F) ppm. Example 20: 2-(T-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-isopropoxy-1H-indol-5-yl)-4- ethyl-5-(hydroxymethyl)-2.4-dihydro-3H-E2.4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1, Steps A-C, except using 5-bromo-7-isopropoxy-1H-indole (Intermediate 9) instead of racemic 5-bromo-7- ((1,1,1-trifluoropropan-2-yl)oxy)-1H- indole (Intermediate 1) in Step A. MS(ESI): mass calcd. for C₂₃H₂4CIFN₄O₃: 458.2, found 459.1 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.55 (d, J= 1.5 Hz, 1 H), 7.39 - 7.50 (m, 2 H), 7.25 - 7.31 (m, 2 H), 6.89 (d, J= 3.2 Hz, 1 H), 6.42 (d, J= 3.2 Hz, 1 H), 5.85 - 5.87 (m, 1 H), 5.85 (s, 1 H), 5.73 (br s, 1 H), 4.73 (quin, J= 6.1 Hz, 1 H), 4.48 (s, 2 H), 3.78 (q, J= 7.1 Hz, 2 H), 1.35 (d, J= 5.9 Hz, 6 H), 1.27 (t, J= 7.1 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ ppm -114.04 - -113.89 (m, 1

F) ppm.

Example 21 : 2-(1 -(2-Chloro-6-fluorobenzyl)-7-isopropoxyindolin-5-yl)-4-ethyl-5- (hydroxymethyl)-2.4-dihydro-3H-1.2.4-triazol-3-one.

Step A. 5-(((tert-Butyldiphenylsilyl)oxy)methyl)-2-( 1 -(2-chloro-6-fluorobenzyl)-7- isopropoxy- 1 H-indol-5-yl)-4-ethyl-2.4-dihydro-3H- 1.2.4-triazol-3-one. The title compound was prepared in a manner analogous to Example 1, Steps A-B, except using 5- bromo-7-isopropoxy-1H-indole (Intermediate 9) instead of racemic 5-bromo-7-((1,1,1- trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1) in Step A. MS (ESI): mass calcd. for C₃₉H₄₂CIFN₄O₃Si: 696.3, found 697.3 [M+H]⁺. ¹H ¹H NMR (400 MHz, CDCl₃) δ 7.70 (d, J= 6.6 Hz, 4 H), 7.58 (s, 1 H), 7.38 - 7.48 (m, 6 H), 7.35 (s, 1 H), 7.22 - 7.30 (m, 2 H),

6.98 -7.06 (m, 1 H), 6.76 (s, 1 H), 6.39 (s, 1 H), 5.93 (s, 2 H), 4.83 (dt, J= 12.2, 6.0 Hz, 1 H), 4.66 (s, 2 H), 3.91 (q, J= 6.9 Hz, 2 H), 1.45 (d, J= 6.1 Hz, 6 H), 1.37 (t, J = 7.1 Hz, 3 H), 1.09 (s, 9 H) ppm.

Step B: 5-(((tert-Butyldiphenylsilyl)oxy)methyl)-2-( 1 -(2-chloro-6-fluorobenzyl )-7- isopropoxyindolin-5-yl)-4-ethyl-2.4-dihydro-3H- 1.2.4-triazol-3-one. To a solution of 5- (((tert-butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6-fluorobenzyl)-4-fluoro-7- isopropoxy-1H-indol-5-yl)-4-ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one (270 mg, 0.36 mmol) in glacial acetic acid (3 mL) at 0 °C was added NaBH₃CN (69 mg, 1.09 mmol). The reaction mixture was stirred at room temperature for 12 h. The mixture was partitioned between ethyl acetate and saturated aqueous NaHCO₃ solution. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The combined organic extract washed with brine, dried over Na₂SO₄ and concentrated to give the crude product as a yellow solid (300 mg, 100%). MS(ESI): mass calcd. for C₃₉H₄₄ClFN₄O₃Si: 698.3, found 699.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.70 (dd, J= 7.9, 1.4 Hz, 4 H), 7.36 - 7.50 (m, 7 H), 7.18 - 7.28 (m, 3 H), 6.97 - 7.04 (m, 1 H), 4.89 (d, J= 1.7 Hz, 2 H), 4.66 - 4.73 (m, 1 H), 4.64 (s, 2 H), 3.85 - 3.94 (m, 2 H), 3.17 - 3.26 (m, 2 H), 2.85 - 2.93 (m, 2 H), 1.34 - 1.44 (m, 9 H), 1.10 (s, 9 H) ppm.

Step C. 2-( 1 -(2-Chloro-6-fluorobenzyl)-7-isopropoxyindolin-5-yl)-4-ethyl-5- lhydroxymethyl)-2.4-dihydro-3H- 1.2.4-triazol-3-one. To a solution of 5-(((tert- butyldiphenylsilyl)oxy)methyl)-2-(1-(2-chloro-6-fluorobenzyl)-7-isopropoxyindolin-5-yl)- 4-ethyl-2,4-dihydro-3H-1,2,4-triazol-3-one (325 mg, 0.47 mmol) in tetrahydrofuran (22 mL), was added Et3N.3HF (1.1 g, 2.83 mmol). The reaction mixture was stirred at 60 °C for 1 h. The mixture was concentrated. The residue was purified by was purified by preparative reversed phase HPLC (Stationary phase: Phenomenex Gemini-NX, 5 μm, 150 x 30 mm; Mobile phase: water (0.04% NH₃H₂O + 10 mM NH₄HCO₃) (A) - MeCN (B), gradient elution: 52 - 82% B in A over 8 min, flow rate: 25 mL/min) to give the title compound as a white solid (130 mg, yield: 60%). MS(ESI): mass calcd. for C₂₃H₂₆CIFN₄O₃: 460.2, found 461.1 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 7.35 - 7.44 (m, 2 H), 7.32 (s, 1 H), 7.21 - 7.29 (m, 1 H), 7.19 (s, 1 H), 5.71 (br s, 1 H), 4.80 (s, 2 H), 4.58 (dt, J= 11.9, 5.9 Hz, 1 H), 4.45 (d, J= 3.7 Hz, 2 H), 3.75 (q, J= 7.1 Hz, 2 H), 3.04 - 3.13 (m, 2 H), 2.78 - 2.86 (m, 2 H), 1.32 (d, J= 5.9 Hz, 6 H), 1.25 (t, J= 7.1 Hz, 3 H); ¹⁹F NMR (376 MHz, DMSO-d₆) δ ppm -111.83 (d, J= 6.6 Hz, 1 F) ppm.

Example 22: Racemic 2-(1-((2-Chloropyridin-4-yl)methyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one.

The title compound was prepared in a manner analogous to Example 1 , Steps A-C, using racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)indoline (Intermediate 2) instead of racemic 5-bromo-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indole (Intermediate 1); and using 2-chloro-4-(chloromethyl)pyridine instead of 2-(bromomethyl)-1-chloro-3- fluorobenzene in Step A. MS (ESI): mass calcd. for C₂₂H₂₃CIF₃N₅O₃, 497.1; m/z found, 498.2 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J= 5.1 Hz, 1 H), 7.39 (s, 1 H), 7.35 (d, J= 7.1 Hz, 2 H), 7.21 (d, J= 4.9 Hz, 1 H), 4.70 - 4.79 (m, 1 H), 4.62 - 4.70 (m, 3 H), 4.49 - 4.60 (m, 1 H), 3.87 (q, J= 7.3 Hz, 2 H), 3.27 - 3.42 (m, 2 H), 3.01 - 3.09 (m, 2 H), 2.40 (br s, 1 H), 1.44 (d, J= 6.4 Hz, 3 H), 1.39 (t, J= 7.1 Hz, 3 H); ¹⁹F NMR (376 MHz, CDCl₃) δ -78.67 (d, J= 5.9 Hz, 1 F) ppm.

Biological Data DHODH inhibitory activities of the compounds of Examples 1 -22 were assessed using the following assays. The half maximal inhibitory concentration values (IC50) are summarized in Table 3.

Biological Assays

In vitro Assay: DHODH enzymatic assay To detect DHODH enzyme activities, dichloroindophenol (DCIP) is added as the final electron acceptor in the assay. DCIP can accept electrons from the reduced coenzyme Q generated in the assay, or from dihydroorotate (DHO) via FMN by binding presumably to the ubiquinone pocket. DCIP solutions are blue, with an intense absorbance around 600 nm, but becomes colorless upon reduction (J. Biol. Chem. (1986) 261, 11386). The assay buffer contained 50 nM HEPES, pH 7.5, 150 mMNaCl, 0.5 mM EDTA, and 0.1% Triton X-100 in MilliQ water. Substrate consisting of 20 mM DHO, 5mM CoQ₆, and 1mM DCIP in assay buffer, initiates the reaction. The assay is run in end-point mode by quenching the reaction with the potent DHODH inhibitor brequinar. Absorbance measurements were obtained using the BMG Phera Star plate-reading spectrophotomer. Purified human DHODH was purchased from Proteros (cat. No. PR-0044). Chemicals were purchased from Sigma- Aldrich, Teknova, and Avanti Polar Lipids. Liquid handling was performed using Labcyte Echo and Formulatrix Tempest.

In vitro Assay: MOLM-13 Cellular Assay MOLM-13 cells were obtained from DSMZ and were maintained in RPMI 1640 +

Glutamax + 25mM HEPES (Invitrogen, catalog number 72400) supplemented with 10% heat inactivated fetal bovine serum (FBS; Invitrogen, catalog number 16140). The day prior to assay set-up, cells were pelleted, resuspended in fresh media, counted, and cells were plated at 0.4 x 10⁶ cell/mL in a T150 flask. On the day of the assay, cells were pelleted, resuspend in fresh media, counted and seeded at 5,000 cells/well in white opaque 96-well tissue culture treated microplates (Perkin Elmer, catalog number 6005680). Cells were exposed to different concentrations of test compounds at 37 °C, 5% CO₂ for 72 hours immediately after seeding. Cell viability was acquired on a Perkin Elmer Envision 2104 multilabel reader using the CellTiter-Glo assay (Promega) according to the manufacturer’s instructions.

Table 3

Claims

CLAIMS What is claimed is:

1. A compound having the structure of Formula (I):

wherein

X-Y-Z is selected from the group consisting of:

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

wherein

L is selected from the group consisting of: CH₂, NH, CH(CH₃), and C(=O);

R^c is halo or C_1-6alkyl; and

R^d is selected from the group consisting of: H, halo, and C_1-6alkyl; or a pharmaceutically acceptable salt, isotope, N-oxide, solvate, or stereoisomer thereof.

2. The compound according to claim 1,

pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

3. The compound according to claim 1,

pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

4. The compound according to claim 1

pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

5. The compound according to claim 1,

pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

6. The compound according to any of claims 1-5, wherein R¹ is C_1-4alkyl or C_1-4haloalkyl; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

7. The compound according to any of claims 1-5, wherein R¹ is CH₃,

or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

8. The compound according to any of claims 1-7

wherein

R^b is C_1-4alkyl substituted with one OH member; and R^a is C_1-4alkyl; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

9. The compound according to any of claims 1-7,

pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

10. The compound according to any of claims 1 -9, wherein R³ is H; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

11. The compound according to any of claims 1-9, wherein R³ is F; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

12. The compound according to any of claims 1-11, wherein L is CH₂.

13. The compound according to any of claims 1-11, wherein L is NH.

14. The compound according to any of claims 1-11, wherein L is CH(CH₃).

15. The compound according to any of claims 1-11, wherein L is C(=O).

16. The compound according to any of claims 1-15, wherein R⁴ is

wherein R^c is halo or C_1-4alkyl; and

R^d is selected from the group consisting of: H, halo and C_1-4alkyl; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

17. The compound according to any of claims 1-15, wherein R⁴ is

or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

18. The compound according to any of claims 1-15,

wherein

R^c is halo or C_1-4alkyl; and

R^d is selected from the group consisting of: H, halo, and C_1-4alkyl; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

19. The compound according to any of claims 1-15,

or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

20. The compound according to any of claims 1-15,

a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

21. The compound according to claim 1, having the structure of Formula (IA):

wherein

R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

R⁴ is selected from the group consisting of:

wherein

L is selected from the group consisting of: CH₂, CH(CH₃), and C(=O);

R^c is halo or C_1-6alkyl; and R^d is halo or C_1-6alkyl; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

22. The compound according to claim 1, having the structure of Formula (IB):

wherein

R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

L is NH:

R^c is halo; and R^d is halo; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

23. The compound according to claim 1, having the structure of Formula (IC):

wherein

R¹ is C_1-6alkyl or C_1-6haloalkyl;

R^a is C_1-6alkyl;

R^b is C_1-6alkyl substituted with one OH member; R³ is H or F;

L is CH₂:

R^c is halo; and R^d is halo; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

24. A compound selected from the group consisting of:

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1 -trifluoropropan-2-yl)oxy)indolin-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R*)-2-(3 -((2-Chloro-6-fluorophenyl)amino)-4-((1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(3 -((2-Chloro-6-fluoropheny l)amino)-4-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

2-(1-(2-Chloro-6-fluorobenzyl)-7-methoxy-1H-indazol-5-yl)-4-ethyl-5-

(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1 -trifluoropropan-2-yl)oxy)-1H- indazol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; Racemic 2-(1-(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1H-indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R)-2-(1-(2-Chloro-6-fluorobenzyl)-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)indolin-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1 -trifluoropropan-2-yl)oxy)indobn-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

Racemic 1 -Benzyl-4-((5-(4-ethy 1-3 -(hy droxymethy l)-5 -oxo-4, 5-dihydro- 1 H- 1 ,2,4- triazol- 1 -yl)-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)indolin- 1 -yl)methyl)pyridin-2( 1 H)- one;

(R*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-

4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-

4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)-1H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-( 1 -(2-Chloro-6-fluorobenzy l)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(S*)-2-( 1 -(2-Chloro-6-fluorobenzy l)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one; 2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-isopropoxy-1H-indol-5-yl)-4-ethyl-5- (hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; 2-(1-(2-Chloro-6-fluorobenzyl)-7-isopropoxyindolin-5-yl)-4-ethyl-5-(hydroxymethyl)- 2,4-dihydro-3H-1,2,4-triazol-3-one; and Racemic 2-(1-((2-Chloropyridin-4-yl)methyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof.

25. A compound selected from the group consisting of: (S*)-2-(1-(2-chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S)-2-(1-(2-chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-( 1 -(2-chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(S*)-2-( 1 -(2-chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; Racemic 2-(1-(2-chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; and Racemic 2-(1-(2-chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

26. A pharmaceutical composition comprising: (A) a compound according to any of claims 1-25, or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof; and (B) at least one pharmaceutically acceptable excipient.

27. A pharmaceutical composition comprising an effective amount of a compound selected from the group consisting of:

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R*)-2-(3 -((2-Chloro-6-fluorophenyl)amino)-4-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(3 -((2-Chloro-6-fluoropheny l)amino)-4-(( 1,1,1 -trifluoropropan-2-yl)oxy)-1H- indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

2-(1-(2-Chloro-6-fluorobenzyl)-7-methoxy-1H-indazol-5-yl)-4-ethyl-5-

(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indazol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)- 1H-indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indobn-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

Racemic 1 -Benzyl-4-((5-(4-ethy 1-3 -(hy droxymethy l)-5 -oxo-4, 5-dihydro- 1 H- 1 ,2,4- triazol- 1 -yl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-1-yl)methyl)pyridin-2(1H)- one; (R*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-

4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-

4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)-1H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-( 1 -(2-Chloro-6-fluorobenzy l)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; Racemic 2-( 1 -(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(S*)-2-( 1 -(2-Chloro-6-fluorobenzy l)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-(( 1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-isopropoxy-1H-indol-5-yl)-4-ethyl-5- (hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; 2-(1-(2-Chloro-6-fluorobenzyl)-7-isopropoxyindolin-5-yl)-4-ethyl-5-(hydroxymethyl)- 2,4-dihydro-3H-1,2,4-triazol-3-one; and Racemic 2-(1-((2-Chloropyridin-4-yl)methyl)-7-((1,1,1 -trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N- oxide thereof; and at least one pharmaceutically acceptable excipient.

28. A method of treating a subject suffering from or diagnosed with a disease, disorder, or medical condition comprising inhibiting or altering dihydroorotate oxygenase enzyme activity in the subject by administering to the subject an effective amount of at least one compound according to any of claims 1-27, or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.

29. The method according to claim 28, wherein the disorder, disease or medical condition is selected from the group consisting of: inflammatory disorders and autoimmune disorders.

30. The method according to claim 28, wherein the disorder, disease or medical condition is cancer.

31. The method according to claim 28, wherein the disorder, disease or medical condition is selected from the group consisting of: lymphomas, leukemias, carcinomas, and sarcomas.

32. The method according to claim 28, wherein the disorder, disease or medical condition is selected from the group consisting of: acute lymphoblastic leukemia, acute myeloid leukemia, (acute) T-cell leukemia, acute lymphoblastic leukemia, acute lymphocytic leukemia, acute monocytic leukemia, acute promyelocytic leukemia, bisphenotypic B myelomonocytic leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, chronic myeloid leukemia, chronic myelomonocytic leukemia, large granular lymphocytic leukemia, plasma cell leukemia, and also myelodysplastic syndrome, which can develop into an acute myeloid leukemia.

33. The method according to claim 28, wherein the disorder, disease or medical condition is acute myeloid leukemia.

34. The method according to any of claims 28-33, wherein the at least one compound is selected from the group consisting of:

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; (S*)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H-indol-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5- yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R*)-2-(3 -((2-Chloro-6-fluorophenyl)amino)-4-((1,1,1-trifluoropropan-2-yl)oxy)- 1 H- indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(3 -((2-Chloro-6-fluoropheny l)amino)-4-(( 1,1,1 -trifluoropropan-2-yl)oxy)- 1 H- indazol-6-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

2-(1-(2-Chloro-6-fluorobenzyl)-7-methoxy-1H-indazol-5-yl)-4-ethyl-5-

(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indazol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)- 1H-indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S)-2-(1-(2-Chloro-6-fluorobenzyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indobn-5-yl)-4- ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-(1-(1 -(2-Chloro-6-fluorophenyl)ethyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

Racemic 1 -Benzyl-4-((5-(4-ethy 1-3 -(hy droxymethy l)-5 -oxo-4, 5-dihydro- 1 H- 1 ,2,4- triazol- 1 -yl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-1-yl)methyl)pyridin-2( 1 H)- one;

(R*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-

4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(S*)-2-(1-(2-Chloro-6-fluorobenzoyl)-7-((1,1,1-trifluoropropan-2-yl)oxy)indolin-5-yl)-

4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one; (S*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2-yl)oxy)-1H- indol-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

Racemic 2-( 1 -(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(S*)-2-(1-(2-Chloro-6-fluorobenzy l)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indolin-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

(R*)-2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-((1,1,1-trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one;

2-(1-(2-Chloro-6-fluorobenzyl)-4-fluoro-7-isopropoxy-1H-indol-5-yl)-4-ethyl-5-

(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one;

2-(1-(2-Chloro-6-fluorobenzyl)-7-isopropoxyindolin-5-yl)-4-ethyl-5-(hydroxymethyl)- 2,4-dihydro-3H-1,2,4-triazol-3-one; and

Racemic 2-(1-((2-Chloropyridin-4-yl)methyl)-7-((1,1,1-trifluoropropan-2- yl)oxy)indobn-5-yl)-4-ethyl-5-(hydroxymethyl)-2,4-dihydro-3H-1,2,4-triazol-3- one; or a pharmaceutically acceptable salt, solvate, stereoisomer, isotopic variant, or N-oxide thereof.