Tricyclic heteroaryl compounds useful for enhancing innate immune responses

Abstract

The present disclosure provides 5H-pyrrolo[3,2-b:5,4-c']dipyridine compounds, pharmaceutical compositions thereof, and methods of using them to treat and / or prevent viral infections by enhancing one or more innate immune responses within a subject.

Description

Attorney Docket No.71180-431243 (ASP-077-WO) TRICYCLIC HETEROARYL COMPOUNDS USEFUL FOR ENHANCING INNATE IMMUNE RESPONSES CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 707,151, filed October 14, 2024, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION

[0002] Provided are 5H-pyrrolo[3,2-b:5,4-c']dipyridine compounds, pharmaceutical compositions, methods for their preparation, and methods for their use in treating and / or preventing viral infections, and in particular, to certain compounds that can enhance one or more innate immune responses within a subject. BACKGROUND

[0003] Antiviral drugs can work by interacting with the virus to reduce its pathogenicity or by targeting the host to improve the host's defense against the virus. Most antiviral drugs on the market (e.g., zanamivir for treating influenza, zidovudine for treating HIV, acyclovir for treating HSV, and entecavir for treating HBV) interact directly with the virus to reduce pathogenicity. However, viruses can mutate and, thereby, develop resistance to these types of antiviral drugs. Consequently, antiviral drugs aimed at directly targeting a virus are prone to decreased efficacy over time.

[0004] As a result, there is an unmet need for an antiviral drug that targets the host rather than the virus directly. Therapeutic agents that bolster existing host immune mechanisms of viral defense, specifically the host innate immune response to infection, hold potential for treatment of multiple infections with a single agent.Attorney Docket No.71180-431243 (ASP-077-WO)

[0005] Interferon (IFN) is one of the cytokines secreted by immune cells, which activates immune cells and acts on various points in the virus life cycle to suppress the growth of viruses. Currently, injectable pegylated interferon (Peg-IFN) is available for general clinical use. A significant number of patients with Peg-IFN have a therapeutic effect regardless of whether they are HBe antigen positive or negative, and various side effects have been reported.

[0006] WO2013 / 059559 to Glaxo SmithKline, LLC discloses non-nucleic acid, low- molecular-weight, antiviral therapeutics suitable for oral administration. For example, imidazonaphthyridine compound RO8191 and related compounds are reported as IFN mimetic drugs using HCV replicon cells.

[0007] WO2018043747 to Kyoto University discloses imidazonaphthyridine compounds for treatment of HBV.

[0008] WO2023025312 to Assembly Biosciences discloses 2-(imidazo[l,2-a]l,8-naphthyridin- 8- yl)-l,3,4-oxadiazole derivatives of formula (I) as enhancers of innate immune response for the treatment of viral infections.

[0009] There is still a long-felt and unmet need for new non-nucleic acid, low-molecular- weight, antiviral therapeutics, that are not only suitable for oral administration, but also have increased efficacy, safety, and pharmacokinetic profiles. SUMMARY

[0010] The present disclosure provides, in part, 5H-pyrrolo[3,2-b:5,4-c']dipyridine compounds and pharmaceutical compositions thereof, useful for treating viral infections by enhancing one or more innate immune responses within a subject.

[0011] In one aspect, the disclosure provides a compound of Formula I:Attorney Docket No.71180-431243 (ASP-077-WO) or a pharmaceutically are described in the detaileddescription.

[0012] In another aspect, the disclosure provides pharmaceutical compositions comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

[0013] In another aspect, the disclosure provides a method of treating a viral infection in a subject in need thereof, comprising: administering to the subject a therapeutically effective amount of compound of Formula I, or a pharmaceutically acceptable salt thereof.

[0014] In another aspect, the disclosure provides a method of treating a viral infection in a subject in need thereof, comprising: administering to the subject a pharmaceutical composition comprising a therapeutically effective amount of a compound of Formula I, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient. DETAILED DESCRIPTION

[0015] The features and other details of the disclosure will now be more particularly described. Before further description of the present disclosure, certain terms employed in the specification, examples and appended claims are collected here. These definitions should be read in view of theAttorney Docket No.71180-431243 (ASP-077-WO) remainder of the disclosure and as understood by a person of skill in the art. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the art. I. Definitions

[0016] The term “alkyl” as used herein refers to a saturated straight or branched hydrocarbon. Exemplary alkyl groups include, but are not limited to, straight or branched hydrocarbons of 1-6 or 1-4 carbon atoms, referred to herein as C1-6 alkyl and C1-4 alkyl, respectively. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, 2-methyl-1-butyl, 3- methyl-2-butyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3- methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, neopentyl, and n-hexyl, etc.

[0017] The term “alkenyl” as used herein refers to an unsaturated straight or branched hydrocarbon having at least one carbon-carbon double bond. Exemplary alkenyl groups include, but are not limited to, a straight or branched group of 2-6 carbon atoms, referred to herein as C2-6alkenyl. Exemplary alkenyl groups include, but are not limited to, vinyl, allyl, propene, butenyl, and pentenyl, etc.

[0018] The term “alkynyl” as used herein refers to an unsaturated straight or branched hydrocarbon having at least one carbon-carbon triple bond. Exemplary alkynyl groups include, but are not limited to, straight or branched groups of 2-6 carbon atoms, referred to herein as C2-6alkynyl. Exemplary alkynyl groups include, but are not limited to, ethynyl, propynyl, butynyl, pentynyl, hexynyl, and methylpropynyl, etc.

[0019] The term “alkoxy” as used herein refers to a straight or branched alkyl group attached to oxygen (i.e., alkyl-O-). Exemplary alkoxy groups include, but are not limited to, alkoxyAttorney Docket No.71180-431243 (ASP-077-WO) groups of 1-6 or 1-4 carbon atoms, referred to herein as C1-6alkoxy and C1-4alkoxy, respectively. Exemplary alkoxy groups include, but are not limited to methoxy, ethoxy, and isopropoxy, etc.

[0020] The term “cycloalkyl” as used herein refers to a saturated monocyclic hydrocarbon group of, for example, 3-7 carbons, referred to herein as monoC3-7cycloalkyl, or bicyclic hydrocarbon ring structure of, for example, 5-12 carbons, referred to herein as biC5-12cycloalkyl. For bicyclic cycloalkyl groups, the two rings may be attached through the same or different carbons. Exemplary monocycloalkyl groups include, but are not limited to, cycloheptyl, cyclohexyl, cyclopentyl, cyclobutyl and cyclopropyl. Exemplary bicycloalkyl groups include, but are not limited to, spiro[2.5]octanyl, spiro[3.5]nonanyl, spiro[4.5]decanyl, spiro[5.5]undecanyl, spiro[2.4]heptanyl, spiro[3.4]octanyl, spiro[4.4]nonanyl, spiro[2.3]hexanyl, spiro[3.3]heptanyl, decahydronaphthalene, octahydro-1H-indene, bicyclo[4.2.0]octanyl, bicyclo[4.1.0]heptanyl, octahydropentalenyl, bicyclo[3.2.0]heptanyl, bicyclo[3.1.0]hexanyl, bicyclo[2.2.2]octanyl, bicyclo[2.2.1]heptanyl, bicyclo[3.1.1]heptanyl, and bicyclo[1.1.1]pentanyl.

[0021] The term “halo” or “halogen” as used herein refers to F, Cl, Br or I.

[0022] The term “haloalkyl” as used herein refers to an alkyl group substituted with one or more halogen atoms. For example, haloC1-6alkyl refers to a straight or branched alkyl group of 1- 6 carbon atoms substituted with one halogen atom up to 2n+1, where n is number of carbon atoms in the haloalkyl group. Examples include, but are not limited to, -CH2F, -CHCl2, -CHF2, - CF3, CF3CH2-, CH3CF2-, CF3CCl2- and CF3CF2-.

[0023] The term “hydroxyalkyl” as used herein refers to an alkyl group substituted with one or more hydroxy groups. Examples include, but are not limited to, HOCH2-, HOCH2CH2-, CH3CH(OH)CH2- and HOCH2CH(OH)CH2-.Attorney Docket No.71180-431243 (ASP-077-WO)

[0024] The terms “Individual,” “patient,” and “subject” are used interchangeably and include any animal, including mammals, preferably mice, rats, other rodents, rabbits, dogs, cats, swine, cattle, sheep, horses, or primates, and most preferably humans. The compounds or pharmaceutical compositions of the disclosure can be administered to a mammal, such as a human, but can also be administered to other mammals such as an animal in need of veterinary treatment, e.g., domestic animals (e.g., dogs, cats, and the like), farm animals (e.g., cows, sheep, pigs, horses, and the like) and laboratory animals (e.g., rats, mice, guinea pigs, dogs, primates, and the like). The mammal treated in the methods of the disclosure is desirably a mammal in which treatment of HBV infection is desired.

[0025] The term “Pharmaceutically acceptable” includes molecular entities and compositions that do not produce an adverse, allergic or other untoward reaction when administered to an animal, or a human, as appropriate. For human administration, preparations should meet sterility, pyrogenicity, and general safety and purity standards as required by FDA Office of Biologics standards.

[0026] The term “pharmaceutically acceptable carrier” or “pharmaceutically acceptable excipient” as used herein refers to any and all solvents, dispersion media, coatings, isotonic and absorption delaying agents, fillers, and the like, that are compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. The compositions may also contain other active compounds providing supplemental, additional, or enhanced therapeutic functions.

[0027] The term “pharmaceutical composition” as used herein refers to a composition comprising at least one compound as disclosed herein formulated together with one or more pharmaceutically acceptable excipients.Attorney Docket No.71180-431243 (ASP-077-WO)

[0028] The term "pharmaceutically acceptable salt(s)" as used herein refers to salts of acidic or basic groups that may be present in compounds used in the compositions. Compounds included in the present compositions that are basic in nature are capable of forming a wide variety of salts with various inorganic and organic acids. The acids that may be used to prepare pharmaceutically acceptable acid addition salts of such basic compounds are those that form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, including, but not limited to, malate, oxalate, chloride, bromide, iodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, tartrate, oleate, tannate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucaronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate (i.e., 1,1'-methylene-bis-(2-hydroxy-3- naphthoate)) salts. Compounds included in the present compositions that are acidic in nature are capable of forming base salts with various pharmacologically acceptable cations. Examples of such salts include alkali metal or alkaline earth metal salts, particularly calcium, magnesium, sodium, lithium, zinc, potassium, and iron salts. Compounds included in the present compositions that include a basic or acidic moiety may also form pharmaceutically acceptable salts with various amino acids. The compounds of the disclosure may contain both acidic and basic groups; for example, one amino and one carboxylic acid group. In such a case, the compound can exist as an acid addition salt, a zwitterion, or a base salt.

[0029] The term “therapeutically effective amount” or “effective amount” as used herein refers to the amount of the subject compound that will elicit the biological or medical response of a tissue, system or animal, (e.g., mammal or human) that is being sought by the researcher, veterinarian, medical doctor or other clinician. The compounds or pharmaceutical compositionsAttorney Docket No.71180-431243 (ASP-077-WO) of the disclosure are administered in therapeutically effective amounts to treat a disease. Alternatively, a therapeutically effective amount of a compound is the quantity required to achieve a desired therapeutic and / or prophylactic effect.

[0030] The term “treating” as used herein includes any effect, e.g., lessening, reducing, modulating, or eliminating, a viral infection, that results in the improvement of the disease.

[0031] The compounds of the disclosure may contain one or more chiral centers and, therefore, exist as stereoisomers. The term “stereoisomers” when used herein consist of all enantiomers or diastereomers. These compounds may be designated by the symbols “(+),” “(-),” “R” or “S,” depending on the configuration of substituents around the stereogenic carbon atom, but the skilled artisan will recognize that a structure may denote a chiral center implicitly. The present disclosure encompasses various stereoisomers of these compounds and mixtures thereof. Mixtures of enantiomers or diastereomers may be designated “(±)” in nomenclature, but the skilled artisan will recognize that a structure may denote a chiral center implicitly.

[0032] The compounds of the disclosure may contain one or more double bonds and, therefore, exist as geometric isomers resulting from the arrangement of substituents around a carbon- carbon double bond. The symbol denotes a bond that may be a single, double or triple bond as described herein. Substituents around a carbon-carbon double bond are designated as being in the “Z” or “E” configuration wherein the terms “Z” and “E” are used in accordance with IUPAC standards. Unless otherwise specified, structures depicting double bonds encompass both the “E” and “Z” isomers. Substituents around a carbon-carbon double bond alternatively can be referred to as “cis” or “trans,” where “cis” represents substituents on the same side of the double bond and “trans” represents substituents on opposite sides of the double bond.Attorney Docket No.71180-431243 (ASP-077-WO)

[0033] Compounds of the disclosure may contain a carbocyclic or heterocyclic ring and therefore, exist as geometric isomers resulting from the arrangement of substituents around the ring. The arrangement of substituents around a carbocyclic or heterocyclic ring are designated as being in the “Z” or “E” configuration wherein the terms “Z” and “E” are used in accordance with IUPAC standards. Unless otherwise specified, structurescarbocyclic or heterocyclic rings encompass both “Z” and “E” isomers. Substituents around a carbocyclic or heterocyclic ring may also beor “trans”, where the term “cis” represents substituents on the same side of the plane of the ring and the term “trans” represents substituents on opposite sides of the plane of the ring. Mixtures of compounds wherein the substituents are disposed on both the same and opposite sides of plane of the ring are designated “cis / trans.”

[0034] Individual enantiomers and diastereomers of compounds of the present disclosure can be prepared synthetically from commercially available starting materials that contain asymmetric or stereogenic centers, or by preparation of racemic mixtures followed by resolution methods well known to those of ordinary skill in the art. These methods of resolution are exemplified by (1) attachment of a mixture of enantiomers to a chiral auxiliary, separation of the resulting mixture of diastereomers by recrystallization or chromatography and liberation of the optically pure product from the auxiliary, (2) salt formation employing an optically active resolving agent, (3) direct separation of the mixture of optical enantiomers on chiral liquid chromatographic columns or (4) kinetic resolution using stereoselective chemical or enzymatic reagents. Racemic mixtures can also be resolved into their component enantiomers by well-known methods, such as chiral-phase liquid chromatography or crystallizing the compound in a chiral solvent. Stereoselective syntheses, a chemical or enzymatic reaction in which a single reactant forms an unequal mixture of stereoisomers during the creation of a new stereocenter or during theAttorney Docket No.71180-431243 (ASP-077-WO) transformation of a pre-existing one, are well known in the art. Stereoselective syntheses encompass both enantiomeric and diastereoselective transformations and may involve the use of chiral auxiliaries. For examples, see Carreira and Kvaerno, Classics in Stereoselective Synthesis, Wiley-VCH: Weinheim, 2009.

[0035] The compounds disclosed herein can exist in solvated as well as unsolvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like, and it is intended that the disclosure embrace both solvated and unsolvated forms. In one embodiment, the compound is amorphous. In one embodiment, the compound is a single polymorph. In another embodiment, the compound is a mixture of polymorphs. In another embodiment, the compound is in a crystalline form.

[0036] The disclosure also embraces isotopically labeled compounds of the disclosure which are identical to those recited herein, except that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the disclosure include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine and chlorine, such as2H,3H,13C,14C,15N,18O,17O,31P,32P,35S,18F, and36Cl, respectively. For example, a compound of the disclosure may have one or more H atom replaced with deuterium.

[0037] Certain isotopically-labeled disclosed compounds (e.g., those labeled with3H and14C) are useful in compound and / or substrate tissue distribution assays. Tritiated (i.e.,3H) and carbon- 14 (i.e.,14C) isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium (i.e.,2H) may afford certain therapeutic advantages resulting from greater metabolic stability (e.g., increased in vivo half-life or reduced dosage requirements) and hence may be preferred in some circumstances. IsotopicallyAttorney Docket No.71180-431243 (ASP-077-WO) labeled compounds of the disclosure can generally be prepared by following procedures analogous to those disclosed in the examples herein by substituting an isotopically labeled reagent for a non-isotopically labeled reagent. II. Compounds of the Invention

[0038] In one aspect, the present disclosure provides a compound of Formula 1, or a pharmaceutically acceptable salt thereof, wherein: R1is halo, cyano, C1-6alkyl, C2-6alkenyl, C2-6alkynyl or haloC1-6alkyl; R2is halo, cyano, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, haloC1-6alkyl, monoC3-7cycloalkyl, phenyl or pyridyl, wherein the monoC3-7cycloalkyl, phenyl or pyridyl is optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, hydroxyl, RaRbN, C1-6alkyl, haloC1-6alkyl, hydroxyC1-6alkyl and C1-6alkoxy; R3is hydrogen, C1-6alkyl or haloC1-6alkyl; and Raand Rbare independently selected for each occurrence from the group consisting of hydrogen and C1-4alkyl. III. Methods of Use

[0039] Without being bound by any theory, since the compounds of the present disclosure behave as interferon mimicking agents (IFN mimetic agents), it is believed that may exhibit theirAttorney Docket No.71180-431243 (ASP-077-WO) antiviral activity through a variety of mechanisms. One such mechanism involves modulating the expression of interferon-stimulated genes (ISGs) through the janus kinase / signal transducer and activator (JAK / STAT) pathway, a common target for attack by a variety of viruses (Fleming, 2016, herein incorporated by reference with regard to such background teaching). Like other antiviral agents – the compounds of the present disclosure may also function as protease or polymerase inhibitors, disrupt the viral replication machinery or have general anti-viral activity against viral components. The presence of these mechanisms in a broad group of viruses suggests the compounds disclosed herein may provide therapeutic anti-viral activity against a diverse group of viruses.

[0040] Thus, one aspect described herein is a method of treating a hepatitis B infection (HBV) in a patient in need thereof is provided, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating a hepatitis B infection in a patient in need thereof is provided, comprising administering to a subject or patient a therapeutically effective amount of a disclosed pharmaceutical composition or a pharmaceutical composition comprising a disclosed compound, or two or more disclosed compounds, and a pharmaceutically acceptable excipient.

[0041] With regard to HBV / hepatitis D (HDV) coinfection or superinfection, HDV encodes HDAg, the HDV protein responsible for HDV RNA replication. HDV infection is facilitated by the interaction of HDAg with HBV viral envelope protein HBsAg, for both entry into the hepatocytes and assembly and release of the HDV virions (Negro, 2014). Thus, because HDV infection is dependent on the presence of an existing HBV infection, strategies for treating HBV / HDV coinfection may focus on targeting HBV alone, HDV alone or both viruses together.Attorney Docket No.71180-431243 (ASP-077-WO)

[0042] Thus, the present disclosure also contemplates a method of treating an HBV or HDV infection, or HBV / HDV coinfection, in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating an HBV or HDV infection or HBV / HDV coinfection in a patient in need thereof is provided, comprising administering to a subject or patient a therapeutically effective amount of a disclosed pharmaceutical composition or a pharmaceutical composition comprising a disclosed compound, or two or more disclosed compounds, and a pharmaceutically acceptable excipient.

[0043] In some aspects, the disclosure provides a method of treating a hepatitis B infection in a patient in need thereof, comprising administering a first compound selected from any one of the disclosed compounds, in combination with one or more other HBV agents each selected from the group consisting of HBV capsid assembly promoters, HBV viral polymerase interfering nucleosides, viral entry inhibitors, HBsAg secretion inhibitors, disruptors of nucleocapsid formation, cccDNA formation inhibitors, antiviral core protein mutant, HBc directed transbodies, RNAi targeting HBV RNA, immunostimulants, TLR-7 / 9 agonists, cyclophilin inhibitors, HBV vaccines, SMAC mimetics, epigenetic modulators, kinase inhibitors, and STING agonists. In some embodiments, the disclosure provides a method of treating a hepatitis B infection in a patient in need thereof, comprising administering an amount of a disclosed compound, and administering another HBV capsid assembly promoter therapeutic. Other combinations contemplated herein include administering a first compound selected from any one of the disclosed compounds, in combination with any available HBV treatment, including not limitedAttorney Docket No.71180-431243 (ASP-077-WO) to, entecavir, tenofovir, Baraclude, Viread, lamivudine, Vemlidy, Hepsera, Epivir-HBV, adefovir, epivir, tenofovir alafenamide, and other suitable HBV drugs.

[0044] In some aspects, the disclosure further provides a method of treating HBV or HDV infection or HBV / HDV coinfection in a patient in need thereof, comprising administering a first compound selected from any one of the disclosed compounds, and one or more other additional antivirals, the one or more additional antivirals include HDV therapies, such as lonafarnib, and one or more of HBV agents each selected from the group consisting of HBV capsid assembly promoters, HBV viral polymerase interfering nucleosides, viral entry inhibitors, HBsAg secretion inhibitors, disruptors of nucleocapsid formation, cccDNA formation inhibitors, antiviral core protein mutant, HBc directed transbodies, RNAi targeting HBV RNA, immunostimulants, TLR-7 / 9 agonists, cyclophilin inhibitors, HBV vaccines, SMAC mimetics, epigenetic modulators, kinase inhibitors, and STING agonists. In some embodiments, the disclosure provides a method of treating an HBV or HDV infection or HBV / HDV coinfection in a patient in need thereof, comprising administering an amount of a disclosed compound, and administering another HBV therapeutic or an HDV therapeutic.

[0045] Another IFN mimetic, RO 8191 has demonstrated antiviral activity against hepatitis C virus (HCV) (Wang et al., 2015), Corona viruses (WO2022 / 049521), and Zika virus (ZIKV) (Fernandes et al., 2021). Given that the compounds of the instant disclosure are also IFN mimicking agents anti-viral activity against HCV, Corona virus and Zika virus is also contemplated herein.

[0046] Thus, another aspect described herein is a method of treating a hepatitis C virus (HCV) infection in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound andAttorney Docket No.71180-431243 (ASP-077-WO) optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating an HCV infection in a patient in need thereof is provided, comprising administering to a subject or patient a therapeutically effective amount of a disclosed pharmaceutical composition or a pharmaceutical composition comprising a disclosed compound, or two or more disclosed compounds, and a pharmaceutically acceptable excipient.

[0047] In some aspects, the disclosure provides a method of treating a hepatitis C infection in a patient in need thereof, comprising administering a first compound selected from any one of the disclosed compounds, in combination with suitable treatments for HCV including, but not limited to, lbasvir / Grazoprevir (Zepatier), Glecaprevir / Pibrentasvir (Mavyret), Sofosbuvir / Ledipasvir (Harvoni), Sofosbuvir / Velpatasvir (Epclusa), second line hepatitis C medications such as Sofosbuvir / Velpatasvir / Voxelaprevir (Vosevi), and other suitable HCV drugs.

[0048] Coronaviruses are another possible viral target for the compounds of the present disclosure (See, for example, WO2022 / 049521). Thus, another aspect of the present disclosure provides methods for treating viral infection, wherein said viral infection comprises one or more viruses from the Coronaviridae family including human coronavirus, Severe Acute Respiratory Syndrome coronavirus (SARS-CoV), Middle East Respiratory Syndrome coronavirus (MERS- CoV) and Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV- 2). The diseases caused by these viruses are SARS (SARS-CoV), MERS (MERS-CoV) and COVID-19 (SARS- CoV-2). Another aspect described herein, are methods for treating viral infections, and the disease caused by such viral infection, wherein said viral infection is SARS-CoV, and the resulting disease is SARS, MERS-CoV, and the resulting disease is MERS, or SARS-CoV-2, and the disease is COVID-19.Attorney Docket No.71180-431243 (ASP-077-WO)

[0049] In some aspects, the disclosure provides a method of treating any Coronaviridae viral infection in a patient in need thereof, comprising administering a first compound selected from any one of the disclosed compounds, in combination with suitable treatments for Coronavirus infection including, but not limited to, nirmatrelvir, ritonavir, Lagevrio (molnupiravir), baricitinib, and the various coronavirus vaccines and other suitable Coronavirus drugs.

[0050] Another aspect described herein, is a method of treating a Zika virus (ZIKV) viral infection in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating a ZIKV infection in a patient in need thereof is provided, comprising administering to a subject or patient a therapeutically effective amount of a disclosed pharmaceutical composition or a pharmaceutical composition comprising a disclosed compound, or two or more disclosed compounds, and a pharmaceutically acceptable excipient.

[0051] In some aspects, the disclosure provides a method of treating a Zika virus infection in a patient in need thereof, comprising administering a first compound selected from any one of the disclosed compounds, in combination with suitable treatments for ZIKV infection. Although there are no medications to treat ZIKV, because treatment includes over the counter use of pain, anti-inflammatory drugs, suitable drugs for combining administration of the compounds of the instant disclosure include acetaminophen, ibuprofen, non-steroidal anti-inflammatory drugs and hydration therapies.

[0052] Human papillomavirus (HPV) is another common sexually transmitted virus with more than 100 known varieties. Interferons have been successfully used to treat HPV infections, making this virus an ideal candidate for treatment by the compounds of the present disclosure.Attorney Docket No.71180-431243 (ASP-077-WO) Thus, another aspect described herein, is a method of treating HPV infection in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating a HPV infection in a patient in need thereof is provided, comprising administering to a subject or patient a therapeutically effective amount of a disclosed pharmaceutical composition or a pharmaceutical composition comprising a disclosed compound, or two or more disclosed compounds, and a pharmaceutically acceptable excipient.

[0053] Combination therapy with the compounds disclosed herein, and known HPV drugs are also contemplated herein. In some aspects, the disclosure provides a method of treating any HPV viral infection in a patient in need thereof, comprising administering a first compound selected from any one of the disclosed compounds, in combination with suitable treatments for HPV infection including, but not limited to, condylax (podofilox), trichloroacetic acid, aldara (imiquimod), zyclara, keratoyltic agents, immune response modifiers, and various commonly used HPV vaccines.

[0054] Prion infection results in fatal brain diseases and encephalopathies in both humans and animals. Recombinant and IFN mimicking interferon therapy have both been found to possibly protect neurons from prion infections (Ishibashi, 2019). Thus, one aspect described herein is a method of treating prion infection in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating a prion infection in a patient in need thereof is provided, comprising administering to a subject or patient a therapeutically effective amount of a disclosedAttorney Docket No.71180-431243 (ASP-077-WO) pharmaceutical composition or a pharmaceutical composition comprising a disclosed compound, or two or more disclosed compounds, and a pharmaceutically acceptable excipient.

[0055] Chikungunya virus (CHIKV) and Dengue virus are both related mosquito-borne viruses with no approved therapies. Studies have demonstrated that CHIKV replication has been found to be inhibited by an agonist of Liver X receptor (LXR-623) by activation of the interferon signaling pathway (Hwang et al., 2019), and halofuginone has been found to work synergistically with another IFN mimicking agent. Thus, both CHIKV and Dengue virus represent yet another group of viruses ideally suited for therapy with the compounds described herein. Without being bound by any theory, it is possible the compounds of the present disclosure could demonstrate a synergistic effect with LXR-623 agonists for the treatment of CHIKV and / or with halofuginone for the treatment of both CHIV and Dengue virus. Thus, another embodiment described herein is a method of treating CHIKV by administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In one aspect, a method of treatment would include administering any of the disclosed compounds in combination with LXR-623. In another aspect described herein is a method of treating CHIKV virus comprising administering to a subject in need thereof, a combination of the compounds disclosed herein and LXR-623 or halofuginone. In yet another aspect, is a method of treating Dengue virus comprising administering to a subject in need thereof, a combination of the compounds disclosed herein and halofuginone.

[0056] Without being bound by any theory, it is further understood that the compounds of the present disclosure may be useful for the treatment of human norovirus (HNV) and encephalomyocarditis virus (EMCV) – both of which have been found to be respond to interferon-mediated antiviral therapy (de Graff et al., 2016; Campillay-Veliz et al., 2020)). Thus,Attorney Docket No.71180-431243 (ASP-077-WO) another aspect described herein is a method of treating HNV infection in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s). In another embodiment, a method for treating a EMCV infection in a patient in need thereof, comprising administering to a subject or patient an effective amount of a disclosed compound, and / or administering a first disclosed compound and optionally, an additional, different disclosed compound(s).

[0057] Further contemplated herein is a method for treating any of the viral infections described herein, in a subject that has been diagnosed with said viral infection or is at risk of developing said viral infection comprising administering to said subject, any one of the compounds described herein.

[0058] Another aspect described herein, is a method for enhancing the immune response to a viral infection from any of the viruses described herein, in a subject that is immunocompromised or is at risk of developing an immunocompromised immune system, comprising administering to said subject, any of the compound as described herein. IV. Administration and Formulations

[0059] In further embodiments, there is provided a pharmaceutical composition comprising a pharmaceutically acceptable diluent and a therapeutically effective amount of a compound of Formula (I) or a pharmaceutically acceptable salt thereof. The chemical entities are administered at a therapeutically effective dosage, e.g., a dosage sufficient to provide treatment for the disease.

[0060] The compounds of the present invention can also be supplied in the form of a pharmaceutically acceptable salt. The term "pharmaceutically acceptable salt" refers to salts prepared from pharmaceutically acceptable inorganic and organic acids and bases.Attorney Docket No.71180-431243 (ASP-077-WO)

[0061] Pharmaceutically acceptable inorganic bases include metallic ions. More preferred metallic ions include, but are not limited to, appropriate alkali metal salts, alkaline earth metal salts and other physiologically acceptable metal ions. Salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like and in their usual valences. Exemplary salts include aluminum, calcium, lithium, magnesium, potassium, sodium and zinc. Particularly preferred are ammonium, calcium, magnesium, potassium, and sodium salts.

[0062] Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary, and tertiary amines, including in part, trimethylamine, diethylamine, N, N'- dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procaine; substituted amines including naturally occurring substituted amines; cyclic amines; quaternary ammonium cations; and basic ion exchange resins, such as arginine, betaine, caffeine, choline, Ν,Ν-dibenzylethylenediamine, diethylamine, 2- diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N- ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine and the like.

[0063] Illustrative pharmaceutically acceptable acid addition salts of the compounds of the present invention can be prepared from the following acids, including, without limitation formic, acetic, propionic, benzoic, succinic, glycolic, gluconic, lactic, maleic, malic, tartaric, citric, nitic, ascorbic, glucuronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, hydrochloric, hydrobromic, hydroiodic, isocitric, trifluoroacetic, pamoic, propionic, anthranilic, mesylic,Attorney Docket No.71180-431243 (ASP-077-WO) oxalacetic, oleic, stearic, salicylic, p-hydroxybenzoic, nicotinic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, phosphoric, phosphonic, ethanesulfonic, benzenesulfonic, pantothenic, toluenesulfonic, 2-hydroxyethanesulfonic, sulfanilic, sulfuric, salicylic, cyclohexylaminosulfonic, algenic, β-hydroxybutyric, galactaric and galacturonic acids. Preferred pharmaceutically acceptable salts include the salts of hydrochloric acid and trifluoroacetic acid. All of the above salts can be prepared by those skilled in the art by conventional means from the corresponding compound of the present invention. For example, the pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. The salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent. The degree of ionization in the salt may vary from completely ionized to almost non-ionized. Lists of suitable salts are found in Remington's Pharmaceutical Sciences. 17th ed., Mack Publishing Company, Easton, Pa., 1985, p.1418, the disclosure of which is hereby incorporated by reference only with regards to the lists of suitable salts.

[0064] In general, the chemical entities provided will be administered in a therapeutically effective amount by any of the accepted modes of administration for agents that serve similar utilities. The actual amount of the chemical entity, i.e., the active ingredient, will depend upon numerous factors such as the severity of the disease to be treated, the age and relative health of the subject, the potency of the chemical entity used, the route and form of administration, andAttorney Docket No.71180-431243 (ASP-077-WO) other factors. The drug can be administered more than once a day, such as once or twice or three times a day.

[0065] Therapeutically effective amounts of the chemical entities described herein may range from approximately 0.01 to 200 mg per kilogram body weight of the recipient per day; such as about 0.01-100 mg / kg / day, for example, from about 0.1 to 50 mg / kg / day. Thus, for administration to a 70 kg person, the dosage range may be about 7-3500 mg per day.

[0066] In addition, the amount of the chemical entity in a composition can vary within the full range employed by those skilled in the art. Typically, the composition will contain, on a weight percent (wt%) basis, from about 0.01-99.99 wt% of at least one chemical entity described herein based on the total composition, with the balance being one or more suitable pharmaceutical excipients. In certain embodiments, at least one chemical entity described herein is present at a level of about 1-80 wt%.

[0067] In certain embodiments, the chemical entities will be administered as pharmaceutical compositions by any one of the following routes: oral, systemic (e.g., transdermal, intranasal or by suppository), sublingually, subcutaneously, topically, intrapulmonarilly, vaginally, rectally, or intraocularly, or parenteral (e.g., intramuscular, intravenous or subcutaneous) administration. In other embodiments, oral administration with a convenient daily dosage regimen that can be adjusted according to the degree of disorder or disease may be used. The choice of administration route and / or formulation depends on various factors such as the mode of drug administration and bioavailability of the drug substance.

[0068] In one embodiment, the compounds of the present invention may be administered topically to the diseased area on the skin or mucous membranes of a subject. In another embodiment, the compounds of the present invention may be administered topically to theAttorney Docket No.71180-431243 (ASP-077-WO) diseased area on the skin or mucous membranes of a subject so that the topical administration allows for the compound to penetrate into the subject's skin layer keratinocyte cells.

[0069] In some embodiments, the compositions are comprised of, in general, at least one chemical entity described herein in combination with at least one pharmaceutically acceptable excipient. Acceptable excipients are non-toxic, aid administration, and do not adversely affect the therapeutic benefit of at least one chemical entity described herein. Such excipient may be any solid, liquid, semi-solid or, in the case of an aerosol composition, gaseous excipient that is generally available to one of skill in the art.

[0070] Solid pharmaceutical excipients include starch, cellulose, talc, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, magnesium stearate, sodium stearate, glycerol monostearate, sodium chloride, dried skim milk and the like. Liquid and semisolid excipients may be selected from glycerol, propylene glycol, water, ethanol and various oils, including those of petroleum, animal, vegetable or synthetic origin, e.g., peanut oil, soybean oil, mineral oil, sesame oil, etc. Liquid carriers, for injectable solutions, include water, saline, aqueous dextrose, and glycols.

[0071] Pharmaceutical compositions or formulations include solid, semi-solid, liquid and aerosol dosage forms, such as, e.g., tablets, capsules, powders, liquids, suspensions, suppositories, aerosols or the like. The chemical entities can also be administered in sustained or controlled release dosage forms, including depot injections, osmotic pumps, pills, transdermal (including electrotransport) patches, and the like, for prolonged and / or timed, pulsed administration at a predetermined rate. In certain embodiments, the compositions are provided in unit dosage forms suitable for single administration of a precise dose.Attorney Docket No.71180-431243 (ASP-077-WO)

[0072] The chemical entities described herein can be administered either alone or more typically in combination with a conventional pharmaceutical carrier, excipient or the like (e.g., mannitol, lactose, starch, magnesium stearate, sodium saccharine, talcum, cellulose, sodium crosscarmellose, glucose, gelatin, sucrose, magnesium carbonate, and the like). If desired, the pharmaceutical composition can also contain minor amounts of nontoxic auxiliary substances such as wetting agents, emulsifying agents, solubilizing agents, pH buffering agents and the like (e.g., sodium acetate, sodium citrate, cyclodextrine derivatives, sorbitan monolaurate, triethanolamine acetate, triethanolamine oleate, and the like). Generally, depending on the intended mode of administration, the pharmaceutical composition will contain about 0.005% to 95%; in certain embodiments, about 0.5% to 50% by weight of a chemical entity. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pennsylvania.

[0073] In certain embodiments, the compositions will take the form of a pill or tablet and thus the composition will contain, along with the active ingredient, a diluent such as lactose, sucrose, dicalcium phosphate, or the like; a lubricant such as magnesium stearate or the like; and a binder such as starch, gum acacia, polyvinylpyrrolidine, gelatin, cellulose, cellulose derivatives or the like. In another solid dosage form, a powder, marume, solution or suspension (e.g., in propylene carbonate, vegetable oils or triglycerides) is encapsulated in a gelatin capsule.

[0074] Liquid pharmaceutically administrable compositions can, for example, be prepared by dissolving, dispersing, etc. at least one chemical entity and optional pharmaceutical adjuvants in a carrier (e.g., water, saline, aqueous dextrose, glycerol, glycols, ethanol or the like) to form a solution or suspension. Injectables can be prepared in conventional forms, either as liquidAttorney Docket No.71180-431243 (ASP-077-WO) solutions or suspensions, as emulsions, or in solid forms suitable for dissolution or suspension in liquid prior to injection. The percentage of chemical entities contained in such parenteral compositions is highly dependent on the specific nature thereof, as well as the activity of the chemical entities and the needs of the subject. However, percentages of active ingredient of 0.01% to 10% in solution are employable and will be higher if the composition is a solid which will be subsequently diluted to the above percentages. In certain embodiments, the composition will comprise from about 0.2 to 2% of the active agent in solution.

[0075] In one embodiment, the compounds of the present invention can be formulated into dermatological topical delivery formulations. Pharmaceutical formulations adapted for topical administration may be formulated as ointments, creams, suspensions, lotions, powders, solutions, pastes, gels, sprays, aerosols or oils. For treatments of external tissues, such as skin, the formulations may be applied as a topical ointment or cream. When formulated in an ointment, the active ingredient may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredient may be formulated in a cream with an oil-in-water cream base or a water-in-oil base.

[0076] In addition to the compounds of the present invention, the compositions herein may additionally include an organic solvent, an adhesive, plasticizer, and a water swellable polymer. The organic solvent may be one or more of dimethylsulfoxide (DMSO), N,N'-dimethylacetamide (DMA), N',N'-dimethylformamide (DMF), dioxane, tetraglycol, or the like.

[0077] Appropriate adhesives for use in the invention include, but are not limited to, polyvinyl alcohol, polyethylene oxides, polyethylene glycols of molecular weight 3350 and higher, hydroxypropylcellulose, and povidone. Polyvinyl alcohol is preferred. The adhesive is typicallyAttorney Docket No.71180-431243 (ASP-077-WO) present in an amount from about 10 to 75% by weight, preferably about 45-55% by weight, and most preferably about 50% by weight of the composition.

[0078] The compositions herein may optionally also include a plasticizer. Suitable plasticizers are typically high-boiling, water-soluble organic compounds containing hydroxyl, amide, or amino groups. Such plasticizers include, but are not limited to, soy, egg or synthetic lecithin, ethylene glycol, tetraethylene, hexamethylene, nonaethylene glycol, formamide, ethanolamine salts, water, glycerin, or combinations thereof. Such plasticizers are well known in the art. A plasticizer is therefore preferably included in the formulation to provide these benefits. The plasticizer is typically present in the composition in an amount ranging from about 0.4-2.0% by weight, with about 1-2% by weight being preferred, and about 0.9% by weight being most preferred.

[0079] The composition may also include a water swellable polymer which acts as an extender and serves to thicken the composition. Such water swellable polymers are well known in the art and include, but are not limited to, microcrystalline cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, methyl cellulose, methyl ethyl cellulose, sodium carboxymethylcellulose, gums, carboxyvinyl polymer, hydroxyethyl cellulose, cornstarch, casein, urea, dextrin, and fume silica. The filler is typically present in an amount from about 1- 10% by weight, preferably about 3-6% by weight, with about 4.67% by weight being most preferred.

[0080] The present invention is further directed to a method of treating warts by applying the pharmaceutical composition(s) topically to the location on the skin where the warts are present. The method of the invention comprises topically applying to a wart on an individual a therapeutically effective amount of the compositions of the invention. The composition may beAttorney Docket No.71180-431243 (ASP-077-WO) applied using an applicator, for example, a swab, sponge, finger cot or a toothpick. While some compositions of this invention can be adhesive in and of themselves, in another embodiment of the invention, the method further comprises occluding the wart with an occluding agent to aid the composition's absorption into the wart, protect the composition from rubbing off, and also further keratolytic activity. Many occluding agents are known to those skilled in the art. These include, but are not limited to, bandages, plastic wrap, and adhesive tape, for example, duct tape.

[0081] The compositions of the invention may further include a variety of substances, including suitable stabilizers, buffers, thickeners, lubricants, wetting, and dissolving agents as well as colorings, moisturizers, preservatives, and fragrances. These minors are added in small amounts and are conventionally known in pharmaceutical formulation work to enhance elegance. Such minors typically comprise less than about 1% of the overall composition.

[0082] In still other embodiments, the compounds of the present invention can be formulated into dermatological delivery formulations, such as a stick-gel, which can be used to target the delivery of the compound directly onto the site of action. For example, if the compounds of the present invention are intended to be used as a treatment for papillomavirus induced warts, then the compound(s) may be formulated into a stick-gel that can apply the compounds in a formulation directly to the surface of the wart. In still other embodiments, the stick-gel application formulation can be based on a PSAs (Pressure Sensitive Adhesives) concept. PSAs, unlike structural adhesives or sealants, differ in that the adhesive-substrate interface does not resist separation when the adhesive is peeled off. In other words, PSAs are intended to show adhesive failure, especially when skin is the substrate, whereas this would be a major fatal flaw for cement and glue. Developing a suitable PSA-GeI for a targeted adherend to treat a skinAttorney Docket No.71180-431243 (ASP-077-WO) common wart, takes the following two critical adhesive attributes into consideration: surface activity and visco-elastic properties.

[0083] As such, these attributes are associated to the three steps of adhesion process. The first step involves contact between the adhesive and the surface. This dynamic step is known as "bonding or sticking" and is dependent on wetting behavior and quick spreadability of the adhesive composition. The second step "adhering" relies on the capacity of the adhesive to remain in contact with surface. This is important for treating warts where the active should be adherent to the warts long enough to exert its intended action. Flowability and creep resistance are the physical characteristics that contribute to maintain the established bond and stick. During this more static phase, the adhesion will build up if the adhesive-to-surface interactions increase (e.g., interpenetration). The third step "debonding" is also dynamic. It consists in separating the adhesive-stick from the surface by means of a peel release process. The peel adhesion property of the adhesive composition will direct the force required to break the bond in an adhesive failure mode.

[0084] The formulation composition to achieve all these attributes can comprise suitable hydrophilic polymers incorporated into a gel matrix containing the active drug in solution. Large organic macromolecules that are either natural or synthetic hydrophilic polymers (e.g., hydroxy propyl methyl cellulose, ethyl cellulose, etc.) on the other hand, exist as randomly coiled chains that entangle with each other to form the gel structure. The nature of the solvent determines whether the gel is a hydrogel (water based) or an organogel (nonaqueous solvent). For example, gels prepared with hydroxyethyl cellulose containing water are hydrogels, whereas gels prepared with polyethylene-containing mineral oil (PIastibase) are organogels. Another class of gels, called thermally sensitive gels, are prepared from poloxamers. In addition to hydrophilicAttorney Docket No.71180-431243 (ASP-077-WO) polymers, silicones are versatile materials permitting the design of various transdermal and topical drug delivery forms. The substantivity to skin can be adjusted from hours to one week in duration. Moreover, the hydrophobic, highly open, and mobile dimethylsiloxane network allows for the preparation of semi-occlusive matrices, permeable to many molecules including the compound(s) of the present invention.

[0085] In other embodiments of the present invention, there is provided sustained release of certain compounds described herein from silicone pressure sensitive adhesive matrices. This capability can also be expanded to other types of silicone matrices including fillerless or reinforced elastomers. As such, modulation of the release of certain compounds of the present invention could enhance drug targeting and therapeutic effectiveness. The silicone formulations could include a loosely cross-linked fillerless elastomer dispersion (Dow Corning® 9040 Silicone Elastomer Blend), a fully cross-linked fillerless elastomer (Dow Corning® 7-9800 A&B Soft Skin Adhesive), a rubber film-forming dispersion (Dow Corning® 7-5300 Film-In-Place Coating), and / or a visco-elastic system (Dow Corning® PSA 7-4502 and 7-4602 pressure sensitive adhesive. In certain embodiments, the compound(s) of the present invention could be formulated in the different silicone and polymer matrices along with the following excipients: surfactants, citric-sodium bicarbonates, and / or carbomer 974.

[0086] Pharmaceutical compositions of the chemical entities described herein may also be administered to the respiratory tract as an aerosol or solution for a nebulizer, or as a microfine powder for insufflation, alone or in combination with an inert carrier such as lactose. In such a case, the particles of the pharmaceutical composition have diameters of less than 50 microns, in certain embodiments, less than 10 microns.Attorney Docket No.71180-431243 (ASP-077-WO)

[0087] For delivery via inhalation the chemical entity can be formulated as liquid solution, suspensions, aerosol propellants or dry powder and loaded into a suitable dispenser for administration. There are several types of pharmaceutical inhalation devices-nebulizer inhalers, metered dose inhalers (MDI) and dry powder inhalers (DPI). Nebulizer devices produce a stream of high velocity air that causes the therapeutic agents (which are formulated in a liquid form) to spray as a mist that is carried into the patient's respiratory tract. MDIs typically are formulation packaged with a compressed gas. Upon actuation, the device discharges a measured amount of therapeutic agent by compressed gas, thus affording a reliable method of administering a set amount of agent. DPI dispenses therapeutic agents in the form of a free-flowing powder that can be dispersed in the patient's inspiratory air stream during breathing by the device. To achieve a free-flowing powder, the therapeutic agent is formulated with an excipient such as lactose. A measured amount of the therapeutic agent is stored in a capsule form and is dispensed with each actuation. Likewise, compressed gases may be used to disperse a chemical entity described herein in aerosol form. Inert gases suitable for this purpose are nitrogen, carbon dioxide, etc. Other suitable pharmaceutical excipients and their formulations are described in Remington's Pharmaceutical Sciences, edited by E. W. Martin (Mack Publishing Company, 18th ed., 1990).

[0088] Recently, pharmaceutical compositions have been developed for drugs that show poor bioavailability based upon the principle that bioavailability can be increased by increasing the surface area, i.e., decreasing particle size. For example, U.S. Patent No. 4,107,288 describes a pharmaceutical formulation having particles in the size range from 10 to 1,000 nm in which the active material is supported on a cross-linked matrix of macromolecules. U.S. Patent No. 5,145,684 describes the production of a pharmaceutical formulation in which the drug substance is pulverized to nanoparticles (average particle size of 400 nm) in the presence of a surfaceAttorney Docket No.71180-431243 (ASP-077-WO) modifier and then dispersed in a liquid medium to give a pharmaceutical formulation that exhibits remarkably high bioavailability. V. Examples

[0089] The compounds described herein can be prepared in a number of ways based on the teachings contained herein and synthetic procedures known in the art. In the description of the synthetic methods described below, it is to be understood that all proposed reaction conditions, including choice of solvent, reaction atmosphere, reaction temperature, duration of the experiment and workup procedures, can be chosen to be the conditions standard for that reaction, unless otherwise indicated. It is understood by one skilled in the art of organic synthesis that the functionality present on various portions of the molecule should be compatible with the reagents and reactions proposed. Substituents not compatible with the reaction conditions will be apparent to one skilled in the art, and alternate methods are therefore indicated. The starting materials for the examples are either commercially available or are readily prepared by standard methods from known materials.

[0090] At least some of the compounds identified as “intermediates” herein are contemplated as compounds of the disclosure. Abbreviations: AcOH Acetic acid ACN Acetonitrile DCM Dichloromethane DMA N,N-Dimethylacetamide DMF N,N-Dimethylformamide DMSO Dimethyl sulfoxide DPPF 1,1’-Bis(diphenylphosphino)ferroceneAttorney Docket No.71180-431243 (ASP-077-WO) EA, EtOAc Ethyl acetate Eaton's reagent 7.7wt% phosphorus pentoxide in methanesulfonic acid Et3N Triethylamine EtOH Ethanol h, hr Hour(s) HPLC High performance liquid chromatography LCMS Liquid chromatography–mass spectrometry MeOH Methanol PE Petroleum ether PPA Polyphosphoric acid TsOH p-Toluenesulfonic acid rt Room temperature TEA Triethylamine THF Tetrahydrofuran TLC Thin-layer chromatographyAttorney Docket No.71180-431243 (ASP-077-WO) Example 1. 2-(5-Methyl-2,4-bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridin-8-yl)-1,3,4- oxadiazole

[0091] Step 1. Synthesis of methyl 3-nitro-1H-pyrrolo[2,3-c]pyridine-5-carboxylate (1-2). Potassium nitrate (2.14 g, 21.05 mmol) was added to a stirred solution of methyl 1H-pyrrolo[2,3- c]pyridine-5-carboxylate (1-1) (1.95 g, 11.08 mmol) in conc. H2SO4(10 mL) at 0 °C in an inert atmosphere, , and the resulting reaction mixture slowly warmed to room temperature and stirred for 2 h. After completion of the reaction (monitored by TLC) the mixture was quenched with saturated NaHCO3 solution and stirred for 5-10 min. The precipitated solid obtained was collected by filtration and dried in vacuo to afford 1-2 (2 g, 81.96%) as a yellow solid. TLC: 5% MeOH / DCM (Rf: 0.5) which was used in the next step without further purification. MS (ESI, m / z): calcd. for C9H7N3O4: 221.04; Found: 222.0 [M + 1]+.1H NMR (400 MHz, DMSO-d6): δ 9.02 (d, J = 4.4 Hz, 2H), 8.73 (s, 1H), 3.93 (s, 3H) ppm.Attorney Docket No.71180-431243 (ASP-077-WO)

[0092] Step 2. Synthesis of methyl 3-amino-1H-pyrrolo[2,3-c]pyridine-5-carboxylate (1-3). An autoclave was charged with a solution of methyl 3-nitro-1H-pyrrolo[2,3-c]pyridine-5- carboxylate (1-2) (0.2 g, 0.90 mmol) in MeOH (10 mL) and the reaction mixture was purged with nitrogen for 10 min. To this mixture was added10% Pd / C (40 mg) under nitrogen atmosphere. The resulting mixture was then stirred at room temperature for 2 h under a hydrogen atmosphere at 50 psi. After completion of the reaction (monitored by TLC), the reaction mixture was filtered through a pad of Celite and washed with EtOAc. The filtrate was concentrated under reduced pressure to afford 1-3 (0.1 g, crude) as a pale-yellow solid. TLC: 5% MeOH / DCM (Rf: 0.5). The crude compound was used for the next step without further purification. MS (ESI, m / z): calcd. for C9H9N3O2: 191.07; Found: 192.0 [M + 1]+.

[0093] Step 3. Synthesis of methyl 2,4-bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4- c]dipyridine-8-carboxylate (1-4). A mixture of methyl 3-amino-1H-pyrrolo[2,3-c]pyridine-5- carboxylate (1-3) (0.5 g, 2.62 mmol) and 1,1,1,5,5,5-hexafluoropentane-2,4-dione (1.1 g, 5.24 mmol) in AcOH (20 mL) was heated at 110 °C for 16 h. After completion of the reaction (monitored by TLC), the mixture was cooled to 0 °C, quenched with saturated NaHCO3solution and extracted with EtOAc. The combined organic layers were washed with water, dried over anhydrous Na2SO4,filtered and concentrated under reduced pressure. The resulting residue was purified by CombiFlash chromatography (eluting with 60-70% EtOAc in heptane) to afford 1-4 (50 mg, 5.26%) as a yellow solid. TLC: 50% EtOAc / hexane (Rf: 0.5). MS (ESI, m / z): calcd. for C14H7F6N3O2: 363.04; Found: 364.0 [M + 1]+.

[0094] Step 4. Synthesis of methyl 5-methyl-2,4-bis(trifluoromethyl)-5H-pyrrolo[3,2- b:5,4-c']dipyridine-8-carboxylate (1-5). Cs2CO3(71 mg, 0.22 mmol) was added in smallAttorney Docket No.71180-431243 (ASP-077-WO) portions to a stirred solution of methyl 2,4-bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4- c]dipyridine-8-carboxylate (1-4) (40 mg, 0.11 mmol) in dry THF (5 mL) at 0 °C under a nitrogen atmosphere, and the resulting reaction mixture was stirred at the same temperature for 10 min. To this mixture was added methyl iodide (8.22 µL, 0.13 mmol) at 0 °C and the resulting mixture slowly warmed to room temperature and stirred for 16 h. After completion of the reaction (monitored by TLC), the mixture was quenched with ice cold water and extracted with EtOAc. The combined organic layers were dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure to afford 1-5 (30 mg, crude) as a yellow solid. TLC: 50% EtOAc / heptane (Rf: 0.5). MS (ESI, m / z): calcd. for C15H9F6N3O2: 377.06; Found: 378.2 [M + 1]+.

[0095] Step 5. Synthesis of 5-methyl-2,4-bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridine-8-carbohydrazide (1-6). To a stirred solution of methyl 5-methyl-2,4- bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (1-5) (30 mg, 0.079 mmol) in ethanol (4 mL) was added hydrazine hydrate (16 mg, 0.31 mmol) and the reaction mixture stirred at 90 °C for 2 h. After completion of the reaction, the reaction mixture was concentrated under reduced pressure to dryness. The crude residue obtained was purified by trituration with n- heptane. The solid was filtered and dried in vacuo to afford 1-6 (30 mg, crude) as a yellow solid. TLC: 70% EtOAc / heptane (Rf: 0.3).

[0096] Step 6. Synthesis of 2-(5-methyl-2,4-bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridin-8-yl)-1,3,4-oxadiazole (Example 1). To a stirred solution of 5-methyl-2,4- bis(trifluoromethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carbohydrazide (1-6) (30 mg, 0.079 mmol) in trimethyl orthoformate (2.5 mL) was added TsOH (7 mg, 0.0031 mmol) and the reaction mixture stirred at 80 °C for 1 h. After completion of the reaction (monitored by TLC),Attorney Docket No.71180-431243 (ASP-077-WO) the mixture was concentrated under reduced pressure. The crude compound was purified by preparative HPLC to afford Example 1 (1.5 mg, 5%) as an off-white solid. TLC: 50% EtOAc / heptane (Rf: 0.3). Example 2. 2-(4-(4-Chlorophenyl)-5-methyl-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridin-8-yl)-1,3,4-oxadiazole

[0097] Step 1. Synthesis of 5-chloro-3-nitro-1H-pyrrolo[2,3-c]pyridine (2-2). To a stirred solution of 5-chloro-1H-pyrrolo[2,3-c]pyridine (2-1) (18.00 g, 117.97 mmol) in con. H2SO4(90 mL) was added HNO3 (10.77 g, 117.97 mmol, 69%) dropwise to keep the temperature at 0°C and then stirred for 1 hour at 0°C. The reaction was monitored by LCMS. After completion of reaction, the reaction mixture was poured into ice water (900 mL) and a fine light brown solid was formed. The solid was collected by filtration and dried to give 2-2 (14.00 g, 60.06%) as aAttorney Docket No.71180-431243 (ASP-077-WO) light brown solid. MS (ESI, m / z): calcd. for C7H4ClN3O2: 197.0; Found: 198.0 [M+1]+.1H NMR (300 MHz, DMSO-d6): δ 13.27 (s, 1H), 8.91 (s, 1H), 8.73 (d, J = 0.9 Hz, 1H), 7.96 (d, J = 0.9 Hz, 1H) ppm.

[0098] Step 2. Synthesis of 5-chloro-1-methyl-3-nitro-1H-pyrrolo[2,3-c]pyridine (2-3). To a stirred solution of 5-chloro-3-nitro-1H-pyrrolo[2,3-c]pyridine (2-2) (15.20 g, 76.93 mmol) in DMF (120 mL) was added K2CO3 (21.26 g, 153.86 mmol) and MeI (21.84 g, 153.86 mmol). The reaction mixture was stirred at 80°C for a period of 3 hours. After completion of reaction, the reaction mixture cooled down and quenched by addition of water (600 mL). The aqueous layer was extracted with ethyl acetate (200 mL x 3). The combined organic phase was washed with brine (200 mL), dried over anhydrous Na2SO4and concentrated under reduced pressure to give crude product which was further purified by column chromatography PE / EA = 1:1 to 0:1 to afford 2-3 (10.1 g, 62.04%) as a light brown solid. MS (ESI, m / z): calcd. for C8H6ClN3O2: 211.0; Found: 212.1 [M+1]+.1H NMR (300 MHz, DMSO-d6): δ 8.98 (s, 1H), 8.92 (d, J = 0.9 Hz, 1H), 7.97 (d, J = 0.9 Hz, 1H), 4.03 (s, 3H) ppm.

[0099] Step 3. Synthesis of 5-chloro-1-methyl-1H-pyrrolo[2,3-c]pyridin-3-amine (2-4). To a stirred solution of 5-chloro-1-methyl-3-nitropyrrolo[2,3-c]pyridine (2-3) (5.00 g, 23.63 mmol) in EtOH (50 mL) and H2O (25 mL) was added NH4Cl (10.11 g, 189.02 mmol). The reaction mixture was stirred at 80°C and Fe (6.60 g, 118.14 mmol) was added in portions for a period of 3 hours. After completion of reaction, the reaction mixture was cooled down and filtered through a Celite pad and then extracted with ethyl acetate (100 mL x 3). The combined organic phase was washed with brine (100 mL), dried over anhydrous Na2SO4, and concentrated under reduced pressure to give crude product which was further purified by column chromatography usingAttorney Docket No.71180-431243 (ASP-077-WO) DCM / MeOH = 20:1 to 10:1 to afford 2-4 (2.2 g, 51.27%) as a brown solid. MS (ESI, m / z): calcd. for C8H8ClN3: 181.0; Found: 182.3 [M+1]+.

[0100] Step 4. Synthesis of 8-chloro-5-methyl-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridin-4-ol (2-5). A mixture of 5-chloro-1-methyl-1H-pyrrolo[2,3-c]pyridin-3-amine (2-4) (3.00 g, 16.51 mmol) and ethyl 4,4,5,5,5-pentafluoro-3-oxopentanoate (11.60 g, 49.55 mmol) in Eaton’s reagent (30 mL) was stirred for 3 h at 110oC under nitrogen atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was diluted with water (50 mL). The mixture was basified to Ph = 7 with saturated NaHCO3 (aq.). The resulting mixture was extracted with EtOAc (100 mL x 3). The combined organic layers were washed with brine (50 mL x 3), dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluted with PE / THF (3:1) to afford 2-5 (360.00 mg, 6.20%) as an off-white solid. MS (ESI, m / z): calcd. for C13H7ClF5N3O: 351.0; Found: 352.1 [M+1]+.1H NMR (300 MHz, DMSO-d6): δ 12.17 (s, 1H), 9.09 – 8.69 (m, 1H), 8.37 – 7.85 (m, 1H),(s, 1H), 4.20 (s, 3H) ppm.

[0101] Step 5. Synthesis of methyl 4-hydroxy-5-methyl-2-(perfluoroethyl)-5H-pyrrolo[3,2- b:5,4-c']dipyridine-8-carboxylate (2-6). A mixture of 8-chloro-5-methyl-2-(perfluoroethyl)- 5H-pyrrolo[3,2-b:5,4-c']dipyridin-4-ol (2-5) (360.00 mg, 1.02 mmol), Pd(dppf)Cl2 (149.81 mg, 0.21 mmol) and TEA (310.78 mg, 3.07 mmol) in MeOH (20 mL) was stirred overnight at 120 °C under CO (30 atm) atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was diluted with water (50 mL). The resulting mixture was extracted with EtOAc (60 mL x 3). TheAttorney Docket No.71180-431243 (ASP-077-WO) combined organic layers were washed with brine (60 mL), dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluted with PE / THF (1:1) to afford 2-6 (340.00 mg, 88.51%) as an off-white solid. MS (ESI, m / z): calcd. for C15H10F5N3O3: 375.1; Found: 376.1 [M+1]+.

[0102] Step 6. Synthesis of methyl 5-methyl-2-(perfluoroethyl)-4- (((trifluoromethyl)sulfonyl)oxy)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (2-7). A mixture of methyl 4-hydroxy-5-methyl-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8- carboxylate (2-6) (340.00 mg, 0.91 mmol), Bis(trifluoromethanesulfonyl)aniline (485.52 mg, 1.36 mmol) and TEA (275.06 mg, 2.71 mmol) in DMF (15 mL) was stirred for 3 h at 70 °C under nitrogen atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was diluted with water (30 mL). The resulting mixture was extracted with EtOAc (50 mL x 3). The combined organic layers were washed with brine (20 mL), dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluted with PE / THF (3:1) to afford 2-7 (130.00 mg, 28.28%) as an off- white solid. MS (ESI, m / z): calcd. for C16H9F8N3O5S: 507.0; Found: 508.1 [M+1]+.

[0103] Step 7. Synthesis of methyl 4-(4-chlorophenyl)-5-methyl-2-(perfluoroethyl)-5H- pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (2-8). A mixture of methyl 5-methyl-2- (perfluoroethyl)-4-(((trifluoromethyl)sulfonyl)oxy)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8- carboxylate (2-7) (65.00 mg, 0.13 mmol), (4-chlorophenyl)boronic acid (40.07 mg, 0.26 mmol), Pd(PPh3)4 (14.81 mg, 0.01 mmol) and K2CO3 (53.51 mg, 0.38 mmol) in dioxane / H2O (3 / 0.3 mL) was stirred overnight at 110 °C under nitrogen atmosphere. After completion of theAttorney Docket No.71180-431243 (ASP-077-WO) reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was diluted with water (10 mL). The resulting mixture was extracted with EtOAc (30 mL x 3). The combined organic layers were washed with brine (20 mL), dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluted with PE / THF (2:1) to afford 2-8 (50.00 mg, 83.06%) as a light yellow solid. MS (ESI, m / z): calcd. for C21H13ClF5N3O2: 469.1; Found: 470.1 [M+1]+.

[0104] Step 8. Synthesis of 4-(4-chlorophenyl)-5-methyl-2-(perfluoroethyl)-5H- pyrrolo[3,2-b:5,4-c']dipyridine-8-carbohydrazide (2-9). A mixture of methyl 4-(4- chlorophenyl)-5-methyl-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (2- 8) (50.00 mg, 0.11 mmol) and NH2NH2·H2O (106.56 mg, 2.12 mmol) in EtOH (2.5 mL) was stirred for 4 h at 70 °C under nitrogen atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was diluted with water (5 mL). The resulting mixture was extracted with EtOAc (10 mL x 3). The combined organic layers were washed with brine (10 mL), dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure to afford 2-9 (50.00 mg, 100.00%) as a light yellow solid. The crude product was used in the next step directly without further purification. MS (ESI, m / z): calcd. for C20H13ClF5N5O: 469.1; Found: 470.0 [M+1]+.

[0105] Step 9. Synthesis of 2-(4-(4-chlorophenyl)-5-methyl-2-(perfluoroethyl)-5H- pyrrolo[3,2-b:5,4-c']dipyridin-8-yl)-1,3,4-oxadiazole (Example 2). A mixture of 4-(4- chlorophenyl)-5-methyl-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carbohydrazide (2-9) (50.00 mg, 0.11 mmol) and TsOH (9.16 mg, 0.05 mmol) in CH(OMe)3 (2.5 mL) was stirred for 4 h at 70 °C under nitrogen atmosphere. After completion of the reaction, the mixtureAttorney Docket No.71180-431243 (ASP-077-WO) was allowed to cool down to room temperature. The resulting mixture was concentrated under reduced pressure. The crude product (50.00 mg) was purified by Pre-HPLC Column, XBridge Shield RP18 OBD Column, 19*150 mm, 5µm; mobile phase, Water (0.5% FA) and ACN (20% ACN up to 95% in 5 min) to afford Example 2 (11.00 mg, 21.54%) as an off-white solid.

[0106] Example 3. 2-(4-(4-Chlorophenyl)-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridin-8-yl)-1,3,4-oxadiazole

[0107] Step 1. Synthesis of 5-chloro-1H-pyrrolo[2,3-c]pyridin-3-amine (3-1). To a stirred solution of 5-chloro-3-nitro-1H-pyrrolo[2,3-c]pyridine (2-2) (26.00 g, 131.59 mmol) in EtOH (260 mL) and H2O (130 mL) was added NH4Cl (56.31 g, 1.05 mol). The reaction mixture was stirred at 80°C and Fe (36.74 g, 657.96 mmol) was added in portions for a period of 3 hours. After completion of reaction, the reaction mixture was cooled down and filtered through a Celite pad and then extracted with ethyl acetate (300 mL x 3). The combined organic phase was washedAttorney Docket No.71180-431243 (ASP-077-WO) with brine (300 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure to give crude product which was further purified by column chromatography using DCM / MeOH 20:1 to 10:1 to afford the desired compound 3-1 (19.00 g, 86.15%) as a light brown solid. MS (ESI, m / z): calcd. for C7H6ClN3: 167.0; Found: 168.2 [M+1]+.

[0108] Step 2. Synthesis of 8-chloro-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridin- 4-ol (3-2). Into a 40 mL sealed tube were added 5-chloro-1H-pyrrolo[2,3-c]pyridin-3-amine (3- 1) (5.00 g, 29.83 mmol) and ethyl 4,4,5,5,5-pentafluoro-3-oxopentanoate (13.97 g, 59.66 mmol) and Eaton's reagent (25 mL). The reaction mixture was stirred at 110 °C for 3 h. After completion of reaction, the reaction mixture was cooled down to room temperature and poured into ice water (100 mL) and basified with Sat.NaHCO3till the pH > 7 and then extracted with EA (200 mL x 3). The organic layers were washed with brine (200 mL) and dried over anhydrous Na2SO4, filtered and concentrated in vacuo to give the crude product which was purified by chromatography PE / EA = 1:1 to 0:1 to afford 3-2 (4.20 g, 41.70%) as a light brown solid. MS (ESI, m / z): calcd. for C12H5ClF5N3O: 337.0; Found: 338.0 [M+1]+.1H NMR (300 MHz, DMSO-d6): δ 12.44 (s, 1H), 8.81 (s, 1H), 8.15 (s, 1H), 7.37 (s, 1H) ppm.

[0109] Step 3. Synthesis of methyl 4-hydroxy-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridine-8-carboxylate (3-3). To a solution of 8-chloro-2-(perfluoroethyl)-5H-pyrrolo[3,2- b:5,4-c']dipyridin-4-ol (3-2) (4.40 g, 13.03 mmol) in MeOH (90 mL) in a pressure tank was added TEA (3.30 g, 32.58 mmol) and Pd(dppf)Cl2(0.95 g, 1.30 mmol). The mixture was purged with nitrogen three times and then was pressurized to 30 atm with carbon monoxide at 140°C for 16 h. The reaction mixture was cooled to room temperature and filtered to remove insoluble solids and then concentrated in vacuo to give a residue. The residue was purified columnAttorney Docket No.71180-431243 (ASP-077-WO) chromatography PE / EA = 1:1 to 0:1 to give 3-3 (3.50 g, 74.35%) as a light brown solid. MS (ESI, m / z): calcd. for C14H8F5N3O3: 361.0; Found: 362.0 [M+1]+.

[0110] Step 4. Synthesis of methyl 4-chloro-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridine-8-carboxylate (3-4). To a stirred solution of methyl 4-hydroxy-2-(perfluoroethyl)- 5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (3-3) (3.50 g, 9.21 mmol) in anhydrous DMF (20 mL) and DCE (40 mL) was added POCl3 (7.07 g, 46.09 mmol) and the mixture was stirred for 3 h at 80°C. After completion of the reaction, the reaction mixture was poured into ice water (60 mL) and basified with Sat. aq. NaHCO3 till the pH > 7 and extracted with DCM (50 mL x 3). The organic phase was collected, dried over anhydrous Na2SO4, filtered and concentrated in vacuo to give a residue. The residue was purified by column chromatography PE / EA = 1:1 to 0:1 to give 3-4 (2.70 g, 81.08%) as a light brown solid. MS (ESI, m / z): calcd. for C14H7ClF5N3O2: 379.0; Found: 380.0 [M+1]+.

[0111] Step 5. Synthesis of methyl 4-(4-chlorophenyl)-2-(perfluoroethyl)-5H-pyrrolo[3,2- b:5,4-c']dipyridine-8-carboxylate (3-5). A mixture of methyl 4-chloro-2-(perfluoroethyl)-5H- pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (3-4) (400.00 mg, 1.05 mmol), (4- chlorophenyl)boronic acid (329.49 mg, 2.10 mmol), K2CO3 (440.00 mg, 3.16 mmol) and Pd(Ph3P)4(121.74 mg, 0.10 mmol) in dioxane (20 mL) was stirred for overnight at 110 °C under nitrogen atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was diluted with water (40 mL). The resulting mixture was extracted with EtOAc (50 mL x 3). The combined organic layers were washed with brine (50 mL), dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flashAttorney Docket No.71180-431243 (ASP-077-WO) chromatography with the following conditions: column, C18 silica gel; mobile phase, MeCN in Water (0.1% FA), 20% to 100% gradient in 10 min; detector, UV 254 nm to afford 3-5 (240.00 mg, 49.98%) as an off-white solid. MS (ESI, m / z): calcd. for C20H11ClF5N3O2: 455.0; Found: 456.2 [M+1]+.1H NMR (300 MHz, DMSO-d6): δ 12.81 (s, 1H), 9.17 (d, J = 1.2 Hz, 1H), 8.87 (d, J = 1.2 Hz, 1H), 8.12 (s, 1H), 8.00 – 7.90 (m, 2H), 7.80 – 7.70 (m, 2H), 3.95 (s, 3H) ppm.

[0112] Step 6. Synthesis of 4-(4-chlorophenyl)-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridine-8-carbohydrazide (3-6). A mixture of methyl 4-(4-chlorophenyl)-2- (perfluoroethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carboxylate (3-5) (100.00 mg, 0.22 mmol) and NH2NH2·H2O (219.68 mg, 4.38 mmol) in EtOH (5 mL) was stirred for 4 h at 70 °C under nitrogen atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was concentrated under reduced pressure. The crude product 3-6 was used in the next step directly without further purification. MS (ESI, m / z): calcd. for C19H11ClF5N5O: 455.1; Found: 456.2 [M+1]+.

[0113] Step 7. Synthesis of 2-(4-(4-chlorophenyl)-2-(perfluoroethyl)-5H-pyrrolo[3,2-b:5,4- c']dipyridin-8-yl)-1,3,4-oxadiazole (Example 3). A mixture of 4-(4-chlorophenyl)-2- (perfluoroethyl)-5H-pyrrolo[3,2-b:5,4-c']dipyridine-8-carbohydrazide (3-6) (100.00 mg, 0.22 mmol) and TsOH (56.67 mg, 0.32 mmol) in CH(OMe)3 (5 mL) was stirred for 4 h at 70 °C under nitrogen atmosphere. After completion of the reaction, the mixture was allowed to cool down to room temperature. The resulting mixture was concentrated under reduced pressure. The crude product (100.00 mg) was purified by Pre-HPLC Column, XBridge ShieldAttorney Docket No.71180-431243 (ASP-077-WO) RP18 OBD Column, 19*150 mm, 5µm; mobile phase, Water (0.5% NH3·H2O) and ACN (20% ACN up to 95% in 5 min) to afford Example 3 (13.00 mg, 12.72%) as a light yellow solid.

[0114] Table 1 shows structures and analytical data for representative Examples of the present invention. These compounds can be prepared according to the synthetic schemes described above and using procedures known to those of ordinary skill in the art. Table 1: Analytical data of representative compounds. MS1J , 9 –Attorney Docket No.71180-431243 (ASP-077-WO) 1H NMR MH DM δ d, z, z, δ .9 .1 ), δ s, - ), δ s, z, (t, d,Attorney Docket No.71180-431243 (ASP-077-WO) 1H NMR MH DM δ ), ), m, δ ), ), δ ), ), ), ): – s, H)Attorney Docket No.71180-431243 (ASP-077-WO) 1H NMR (300 MHz, DMSO-d6): δ ), ), = ), δ 3 - ), H) δ s, ), 0VI Biological Data IFNα pathway induction

[0115] HEK293 cells expressing the firefly luciferase gene under the control of ISRE stably integrated into HEK293 cells were obtained from BPS Bioscience. ISRE reporter was used to measure IFNα pathway induction. Upon IFNα stimulation, pospho-STAT1 and phosphor-STAT2Attorney Docket No.71180-431243 (ASP-077-WO) form a complex with IRF9, named as ISGF3, which translocates to the nucleus and activates the transcription of interferon inducible genes (ISGs) through binding to ISRE in the promoter region of ISGs.

[0116] The cells were culture in MEM medium (Corning) supplemented with 10% FBS, 1% non-essential amino acids, 1 mM sodium pyruvate, 1% Penicillin / Streptomycin plus 400 µg / ml of Geneticin. Sub-confluent culture is passaged and split twice a week, not exceeding 30 passages. Cells are detached using 0.05% Trypsin / 0.53mM EDTA solution (Corning).

[0117] For testing the compound effect on IFNα pathway, HEK293 ISRE reporter cells were seeded in 96-well plate at density of 50,000 cells / well 24 hours before treatment in a black clear bottom plate (Corning). Next day, the cells were treated with compounds in a three-fold serial dilution. The final DMSO concentration in each well is normalized to 0.5%. After 24-hour incubation, the activity of ISRE induction was measured using One-Glo luciferase substrate (Promega) on a Tecan Infinite M1000 Pro plate reader. The fold of induction was calculated by the activity of compound treated cells relative to DMSO treated cells. Cell-based HCV replicon assay

[0118] HCV 1b replicon (NanoLuc luciferase) cell line was generated in Huh7-Lunet cells. HCV replicon cells were cultured in DMEM medium (Cytiva) supplemented with 10% FBS, 1% Penicillin / Streptomycin plus 250 µg / ml of Geneticin. Sub-confluent culture of HCV replicon is passaged and split twice a week, not exceeding 40 passages. Cells are detached using 0.25% Trypsin / 2.21 mM EDTA solution (Corning).

[0119] For testing the antiviral activity of compounds, HCV 1b replicon cells were seeded in DMEM medium supplemented with 5% FBS and 1% % Penicillin / Streptomycin at a density ofAttorney Docket No.71180-431243 (ASP-077-WO) 5,000 cells / well in a black clear bottom half-well 96-well plate (Corning), following by the addition of compounds in a three-fold serial dilution. The final DMSO concentration in each well is normalized to 1%. After 48-hour incubation, the luciferase activity was measured using Nano- Glo luciferase substrate (Promega) on a Tecan Infinite M1000 Pro plate reader. The antiviral activity of compound was calculated from the percentage of luciferase signals relative to DMSO treated cells.

[0120] Table 2 provides assay data for exemplified compounds of the invention. The antiviral activity of the exemplified compounds at 20 uM is grouped in the following ranges: A indicates < 25%; B indicates 25% to 50%; C indicates > 50%. The ISRE induction of the exemplified compounds at 20 uM is grouped in the following ranges: A indicates greater than 2 folds; B indicates 0.5-2 fold(s). Table 2. Assay data for exemplified compounds of the invention. Example Antiviral Activity ISRE InductionAttorney Docket No.71180-431243 (ASP-077-WO) 9 A AEQUIVALENTS

[0121] While specific embodiments of the subject disclosure have been discussed, the above specification is illustrative and not restrictive. Many variations of the disclosure will become apparent to those skilled in the art upon review of this specification. The full scope of the disclosure should be determined by reference to the claims, along with their full scope of equivalents, and the specification, along with such variations.

[0122] Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure.

Claims

Attorney Docket No.71180-431243 (ASP-077-WO) CLAIMS:

1. A compound of Formula 1, or a pharmaceutically acceptable salt thereof, wherein: R1is halo, cyano, C1-6alkyl, C2-6alkenyl, C2-6alkynyl or haloC1-6alkyl; R2is halo, cyano, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, haloC1-6alkyl, monoC3-7cycloalkyl, phenyl or pyridyl, wherein the monoC3-7cycloalkyl, phenyl or pyridyl is optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, hydroxy, RaRbN, C1-6alkyl, haloC1-6alkyl, hydroxyC1-6alkyl and C1-6alkoxy; R3is hydrogen, C1-6alkyl or haloC1-6alkyl; and Raand Rbare independently selected for each occurrence from the group consisting of hydrogen and C1-4alkyl.

2. A pharmaceutical composition comprising a compound of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

3. A method of treating a viral infection in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a compound of claim 1, or a pharmaceutically acceptable salt thereof.Attorney Docket No.71180-431243 (ASP-077-WO) 4. A method of treating a viral infection in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a pharmaceutical composition of claim 2.

5. The method of claim 3 or 4, wherein the viral infection is an HBV infection.

6. The method of claim 3 or 4, wherein the viral infection is an HDV infection.

Images