Compounds and their use in treating schistosomiasis

Abstract

The present invention relates to compounds and their use in treating schistosomiasis, in particular to novel compounds having activity as inhibitors of schistosome growth and pharmaceutically acceptable salts or solvates thereof. The present invention also relates to pharmaceutical compositions comprising such compounds, salts or solvates, and to the use of such compounds as medicaments, in particular for the treatment or prevention of schistosomiasis, also known as schistosomiasis.

Description

[0001] This application is a divisional application of the patent application with application number 201880017475.8, application date January 15, 2018, and invention name “Compounds and their use in the treatment of schistosomiasis”. Technical Field

[0002] The present invention relates to compounds of formula (1a), (1b), (1c) and (1d) and pharmaceutically acceptable salts or solvates thereof having activity as Schistosoma growth inhibitors. The present invention also relates to pharmaceutical compositions comprising such compounds, salts or solvates, and the use of such compounds as medicaments, in particular for the treatment or prevention of schistosomiasis (also known as bilharzia). Background Art

[0003] Schistosomiasis is one of the major neglected diseases affecting more than 200 million people in sub-Saharan Africa, the Middle East and South America. It is a parasitic disease caused by flatworms of the genus Schistosoma, such as S. mansoni, S. haemotobium and S. japonicum. The infection begins in the larval stage of the worms, which then develop through the juvenile stage into adults.

[0004] Two drugs, praziquantel and oxamniquine, are approved for the treatment of schistosomiasis. Oxamniquin has a narrow spectrum of activity (only against Schistosoma mansoni). Praziquantel is used worldwide against all three worms, but is known to be insufficiently effective against larvae. Arthemether has also shown activity against schistosomes in repeated-dose tests in humans, but while widely used to treat malaria in artemisinin-based combination therapies, it is not considered a viable compound for schistosomiasis treatment and control because its use against roundworm infections could generate drug-resistant malaria parasites (Keiser J, Utzinger J. Curr Opin Infect Dis .2007 Dec;20(6):605-12).

[0005] The current status of research on new anti-schistosomiasis Future Medicinal Chemistry(Volume 7, Issue 6, 2015). There are many examples of repurposing existing drug molecules and applying known human drug mechanisms to discover new treatments for schistosomiasis. The former includes Abdulla, MH et al. (2009) "Drug discovery for schistosomiasis: hit and lead compounds identified in a library of known drugs by medium-throughput phenotypic screening." PLoS Negl Trop Dis 3(7):e478; Dissous, C. and CGGrevelding (2011) "Piggy-backing the concept of cancer drugs for schistosomiasis treatment: a tangible perspective?" Trends Parasitol 27(2):59-66; and Neves BJ "The antidepressant drug paroxetine as a new lead candidatein schistosome drug discovery" Medicinal Chemistry Communications ,2016,7,1176.

[0006] Known applications of human drug targets in this area include Kuntz, AN et al. (2007). "Thioredoxinglutathione reductase from Schistosoma mansoni: an essential parasite enzyme and a key drug target." PLoS Med 4(6):e206; Long, T. et al. (2010). "Schistosomamansoni Polo-like kinase 1: A mitotic kinase with key functions in parasite reproduction." Int J Parasitol 40(9):1075-1086; Rojo-Arreola, L. et al. (2014). "Chemical and genetic validation of the statin drug target to treat thehelminth disease, schistosomiasis PLoS One 9(1):e87594; Jacques, SA et al. (2015). "Discovery of Potent Inhibitors of Schistosoma mansoni NAD(+)Catabolizing Enzyme." Journal of Medicinal Chemistry 2015 58(8):3582-3592; Mader, P. et al. (2016). "Biarylalkyl Carboxylic Acid Derivatives as NovelAntischistosomal Agents." ChemMedChem 2016,11,1–11; Heimburg, T. et al. (2016). "Structure-Based Design and Synthesis of Novel Inhibitors Targeting HDAC8 from Schistosoma mansoni for the Treatment of Schistosomiasis." J Chem Inf Model 2014 54(10):3005-3019 Journal of Medicinal Chemistry 2016 59(6):2423-2435.

[0007] Large-scale testing of intact schistosomes is limited by available technology. Ramirez B, BQ et al. (2007) "Schistosomes: challenges in compound screening." Expert Opinion on Drug Discovery 2:S53-361; Sayed, AA et al. (2008) "Identification of oxadiazoles as newdrug leads for the control of schistosomiasis." Nat Med 14(4):407-412. We recently described a novel method for high-throughput screening using larval stage schistosomes and then used this method to identify a set of hit molecules. Paveley, RA et al. (2012) "Whole organism high-content screening by label-free, image-based Bayesian classification for parasitic diseases." PLoS Negl Trop Dis6(7):e1762 and Mansour, NR et al. (2016) "High Throughput ScreeningIdentifies Novel Lead Compounds with Activity against Larval, Juvenile and Adult Schistosoma mansoni PLoS Negl Trop Dis 10(4):e0004659. The latter paper disclosed an imidazopyrazine derivative (LSHTM-1945) with relatively weak activity of 4.9-6.7 μM against larval, juvenile and adult stages of Schistosoma mansoni.

[0008] WO2014078813A1 discloses the preparation of imidazopyrazines for the treatment of parasitic diseases (mainly malaria, leishmaniasis and trypanosomiasis). WO2012080232A1 discloses the preparation of substituted imidazopyrazines as Mps-1 and TKK inhibitors that can be used to treat hyperproliferative disorders. WO2007096764A2 discloses the preparation of bicyclic heteroaryl derivatives as cannabinoid receptor modulators. In addition, Kayagil, I. and S. Demirayak (2011). "Synthesis of some 2,3,6,8-tetraarylimidazo[1,2-a]pyrazine derivatives by using either reflux or microwave irradiation method, and investigation their anticancer activities." Turk. J. Chem. 35(1):13-24. WO2016133935 discloses a series of pyrazolo[1,5-c]pyrimidines as kinase inhibitors for the treatment of various cancers.

[0009] There remains a need in the art for additional compounds effective against schistosoma having good pharmacokinetic properties combined with adequate activity against all three major infecting helminths and against both larvae and adults. Summary of the invention

[0010] In a first embodiment, the present invention provides a compound of formula (1a), (1b), (1c) or (1d) or a pharmaceutically acceptable salt or solvate thereof,

[0011]

[0012] in:

[0013] R1 is C1-C4 alkyl optionally substituted by up to 5 F atoms, C3-C6 cycloalkyl optionally substituted by 1 methyl group, or C4-C7 cycloalkylmethyl;

[0014] R2 is H, F, Cl or OMe;

[0015] R3 is H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH;

[0016] R4 is H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH;

[0017] The condition is that R3 and R4 cannot both be H;

[0018] Or R3 and R4, together with the benzene ring to which they are attached, form an indazole group as shown below

[0019]

[0020] R5 is H, F, Cl or OMe;

[0021] R6 is H, F, Cl or OMe;

[0022] X is N or C-R7

[0023] R7 (if present) is H or F;

[0024] R8 is SF5, Br, C1-C3 alkyl optionally substituted by up to 7 F atoms, C3-C4 cycloalkyl, OCH2C≡CH or OC1-C3 alkyl optionally substituted by up to 7 F atoms;

[0025] R9 is H; and

[0026] R 10 It is H, F or Me.

[0027] In a second embodiment, the present invention provides a compound of formula (1a), (1b), (1c) or (1d) as defined above, or a pharmaceutically acceptable salt or solvate thereof, for use in therapy.

[0028] In a third embodiment, the present invention provides a compound of formula (1a), (1b), (1c) or (1d) as defined above or a pharmaceutically acceptable salt or solvate thereof for use in treating schistosomiasis.

[0029] In a fourth embodiment, the present invention provides the use of a compound of formula 1a), (1b), (1c) or (1d) as defined above, or a pharmaceutically acceptable salt or solvate thereof, in the manufacture of a medicament for treating schistosomiasis.

[0030] In a fifth embodiment, the present invention provides a method for treating schistosomiasis, comprising administering to a patient in need thereof a therapeutically effective amount of a compound of formula (1a), (1b), (1c) or (1d) as defined above, or a pharmaceutically acceptable salt or solvate thereof.

[0031] In a sixth embodiment, the present invention provides a pharmaceutical composition comprising (i) a therapeutically effective amount of a compound of formula (1a), (1b), (1c) or (1d) as defined above, or a pharmaceutically acceptable salt or solvate thereof; and (ii) a pharmaceutically acceptable excipient. DETAILED DESCRIPTION

[0032] A. Definition

[0033] Unless otherwise limited in specific cases, the following definitions apply to the terms used throughout the specification.

[0034] As used herein, the term "alkyl" refers to straight and branched chain saturated hydrocarbon groups. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl and sec-butyl.

[0035] As used herein, the term "cycloalkyl" refers to a cyclic saturated hydrocarbon group. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[0036] As used herein, the term "cycloalkylmethyl" refers to a cyclic saturated hydrocarbon group connected to the rest of the molecule through a methylene bridge. Examples of cycloalkylmethyl include cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl and cyclohexylmethyl.

[0037] As used herein, the term "halogen" or "halo" means fluorine, chlorine, bromine or iodine. Fluorine, chlorine and bromine are particularly preferred.

[0038] "Pharmaceutically acceptable salts" means salts such as those described in standard texts on salt formation, see for example: P. Stahl et al., Handbook of Pharmaceutical Salts: Properties, Selection and Use (VCHA / Wiley-VCH, 2002) or SM Berge et al., "Pharmaceutical Salts" (1977) Journal of Pharmaceutical Sciences, 66, 1-19. Suitable salts according to the invention include those formed with organic or inorganic acids or bases. In particular, suitable salts formed with acids according to the invention include those formed with inorganic acids, strong organic carboxylic acids such as unsubstituted or, for example, halogen-substituted alkane carboxylic acids containing 1 to 4 carbon atoms (such as saturated or unsaturated dicarboxylic acids, such as hydroxycarboxylic acids, such as amino acids); or with organic sulfonic acids such as unsubstituted or, for example, halogen-substituted C1-C4 alkyl or aryl sulfonic acids. Pharmaceutically acceptable acid addition salts include those formed from the following acids: hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, citric acid, tartaric acid, acetic acid, phosphoric acid, lactic acid, pyruvic acid, acetic acid, trifluoroacetic acid, succinic acid, perchloric acid, fumaric acid, maleic acid, glycolic acid, lactic acid, salicylic acid, oxaloacetic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, formic acid, benzoic acid, malonic acid, naphthalene-2-sulfonic acid, benzenesulfonic acid, isethionic acid, ascorbic acid, malic acid, phthalic acid, aspartic acid and glutamic acid, lysine and arginine. Other acids may or may not themselves be pharmaceutically acceptable but may also be used to prepare salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable acid addition salts.

[0039] Pharmaceutically acceptable base salts include ammonium salts, alkali metal salts (e.g., potassium and sodium salts), alkaline earth metal salts (e.g., calcium and magnesium salts), and salts formed with organic bases, such as dicyclohexylamine, N-methyl-D-glucosamine, morpholine, thiomorpholine, piperidine, pyrrolidine, mono-, di- or tri-lower alkylamines (e.g., ethyl-, tert-butyl-, diethyl-, diisopropyl-, triethyl-, tributyl- or dimethyl-propylamine), or mono-, di- or trihydroxy lower alkylamines (e.g., mono-, di- or triethanolamine). In addition, corresponding inner salts may be formed.

[0040] "Pharmaceutically acceptable solvate" means a molecular complex comprising a compound of the invention and one or more pharmaceutically acceptable solvent molecules (e.g., water or ethanol). Those skilled in the art of organic chemistry will recognize that many organic compounds can form complexes with solvents in which they react or from which they precipitate or crystallize. These complexes are referred to as "solvates". For example, complexes with water are referred to as "hydrates". When a drug substance incorporates a solvent (such as water) in a stoichiometric or non-stoichiometric amount in the crystal lattice, solvates such as hydrates are present. Screening for the presence of hydrates in drug substances is routine because these substances may be encountered at any stage of the drug manufacturing process or when the drug substance or dosage form is stored. Solvates are described in S. Byrn et al., Pharmaceutical Research, 1995. 12 (7): pp. 954-954; and Water-Insoluble Drug Formulation, 2nd edition R. Liu, CRC Press, p. 553, which are incorporated herein by reference.

[0041] "Therapy" and "treatment" include both preventative and curative treatment of a disorder, disease, or condition. It also includes slowing, interrupting, controlling, or stopping the progression of a disorder, disease, or condition. It also includes preventing, curing, slowing, interrupting, controlling, or stopping the symptoms of a disorder, disease, or condition.

[0042] B. Compounds

[0043] The present invention provides a compound of formula (1a), (1b), (1c) or (1d) as defined above or a pharmaceutically acceptable salt or solvate thereof

[0044]

[0045] The present invention also provides a compound of formula (1a') or (1b') or a pharmaceutically acceptable salt or solvate thereof,

[0046]

[0047] in:

[0048] R1 is C1-C4 alkyl optionally substituted by up to 5 F atoms, C3-C6 cycloalkyl optionally substituted by 1 methyl group, or C4-C7 cycloalkylmethyl;

[0049] R2 is H, F, Cl or OMe;

[0050] R3 is H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH;

[0051] R4 is H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH;

[0052] The condition is that R3 and R4 cannot both be H;

[0053] Or R3 and R4, together with the benzene ring to which they are attached, form an indazole group as shown below

[0054]

[0055] R5 is H, F, Cl or OMe;

[0056] R6 is H, F, Cl or OMe;

[0057] R7 is H or F;

[0058] R8 is SF5 or C1-C3 alkyl substituted by 3 to 7 F atoms;

[0059] R9 is H; and

[0060] R 10 It is H, F or Me.

[0061] B0. Core structure

[0062] In some embodiments, the compounds of the present invention have formula (1a) as defined above.

[0063] In other embodiments, the compounds of the invention have formula (1b) as defined above.

[0064] In other embodiments, the compounds of the present invention have formula (1c) as defined above.

[0065] In other embodiments, the compounds of the invention have formula (1d) as defined above.

[0066] In other embodiments, the compounds of the invention have formula (1a') as defined above.

[0067] In other embodiments, the compounds of the invention have formula (1b') as defined above.

[0068] B1. Substituent R1

[0069] R1 is selected from the group consisting of C1-C4 alkyl optionally substituted by up to 5 F atoms, C3-C6 cycloalkyl optionally substituted by 1 methyl group, and C4-C7 cycloalkylmethyl.

[0070] R1 is preferably selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, cyclopropyl optionally substituted by 1 methyl, cyclobutyl, cyclopropylmethyl, CHF2, CF3 and CH2CF3.

[0071] R1 is more preferably selected from the group consisting of ethyl, isopropyl, cyclopropyl, cyclobutyl, CF3 and CH2CF3.

[0072] B2. Substituent R2

[0073] R2 is selected from the group consisting of H, F, Cl and OMe.

[0074] R2 is preferably selected from the group consisting of: H, F and Cl.

[0075] R2 is more preferably F or Cl.

[0076] R2 is most preferably F.

[0077] B3. Substituent R3

[0078] R3 is selected from the group consisting of H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH.

[0079] R3 is preferably selected from the group consisting of H, OH, OMe and OPO(OH)OH.

[0080] R3 is more preferably H.

[0081] B4. Substituent R4

[0082] R4 is selected from the group consisting of H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH.

[0083] R4 is preferably selected from the group consisting of H, OH, OMe and OPO(OH)OH.

[0084] More preferably R4 is OH.

[0085] Alternatively and preferably, the substituents R3 and R4 are combined with the benzene ring to which they are attached to form an indazole group as shown below

[0086]

[0087] in:

[0088] R9 is H; and

[0089] R 10 Selected from the group consisting of: H, F and Me.

[0090] In a preferred embodiment of the indazole, R 10 Selected from the group consisting of: H and Me

[0091] In a more preferred embodiment of indazole, substituents R9 and R 10 All are H.

[0092] B5. Substituent R5

[0093] R5 is selected from the group consisting of H, F, Cl and OMe.

[0094] R5 is preferably selected from the group consisting of: H and OMe.

[0095] R5 is more preferably H.

[0096] B6. Substituent R6

[0097] R6 is selected from the group consisting of H, F, Cl and OMe.

[0098] R6 is preferably selected from the group consisting of: H and F.

[0099] B7. Substituent X

[0100] X is N or C-R7, wherein R7 is selected from the group consisting of: H and F.

[0101] In one embodiment, X is C-R7.

[0102] B8. Substituent R8

[0103] R8 is selected from the group consisting of: SF5, Br, C1-C3 alkyl optionally substituted by up to 7 F atoms; C3-C4 cycloalkyl; OCH2C≡CH and OC1-C3 alkyl optionally substituted by up to 7 F atoms.

[0104] Alternatively, R8 is selected from the group consisting of SF5 and C1-C3 alkyl substituted with 3 to 7 F atoms.

[0105] R8 is preferably selected from the group consisting of cyclopropyl, cyclobutyl, isopropyl, CH2CF3, OCF3, O i Pr, CF3, CF2CF3 and SF5.

[0106] Alternatively, R8 is preferably selected from the group consisting of CF3, CF2CF3 and SF5.

[0107] B9. Combinations of substituents R2 to R6

[0108] Preferred combinations of substituents R2 to R6 include:

[0109]

[0110] B10. Combination of substituent X and R8

[0111] Preferred combinations of substituents X and R8 include:

[0112]

[0113] Alternative preferred combinations of substituents X and R8 include:

[0114]

[0115] B11. Specific embodiments of compounds of formula (1a), (1b), (1c) and (1d)

[0116] Substituents R1, R2, R3, R4, R5, R6, X, R7, R8, R9 and R 10 Various embodiments of have been discussed above in B1 to B10. These "substituent" embodiments can be combined with any of the "core structure" embodiments discussed above in B0 to form additional embodiments of compounds of formula (1a), (1a'), (1b), (1b'), (1c) and (1d). All embodiments of compounds of formula (1a), (1a'), (1b), (1b'), (1c) and (1d) formed by combining the "substituent" embodiments and the "core structure" embodiments discussed above are within the scope of the present invention, and some additional preferred embodiments of compounds of formula (1a), (1a'), (1b), (1b'), (1c) and (1d) are provided below.

[0117] In a preferred aspect of the first embodiment, the present invention provides a compound of formula (1a), (1a'), (1b), (1b'), (1c) or (1d) or a pharmaceutically acceptable salt or solvate thereof,

[0118] in:

[0119] R1 is methyl, ethyl, n-propyl, isopropyl, cyclopropyl optionally substituted with 1 methyl, cyclobutyl, cyclopropylmethyl, CHF2, CF3 or CH2CF3;

[0120] R2 is H, F or OMe; or R2 is H, F or Cl;

[0121] R3 is H, OH, OMe or OPO(OH)OH;

[0122] R4 is H, OH, OMe or OPO(OH)OH;

[0123] The condition is that R3 and R4 cannot both be H;

[0124] Or R3 and R4 are combined with the benzene ring to which they are attached to form an indazole group as shown below;

[0125]

[0126] R5 is H or OMe;

[0127] R6 is H or F;

[0128] X is N or C-R7, wherein R7 is H or F; or X is C-R7, wherein R7 is H or F;

[0129] R8 is CF3, CF2CF3, CH2CF3, CH(CH3)2, OCF3, OCH(CH3)2, cyclopropyl, cyclobutyl or SF5; or

[0130] R8 is CF3, CF2CF3 or SF5;

[0131] R9 is H; and

[0132] R 10 It's H.

[0133] In a more preferred aspect of the first embodiment, the present invention provides a compound of formula (1a), (1a'), (1b), (1b') or (1c) or a pharmaceutically acceptable salt or solvate thereof,

[0134] in:

[0135] R1 is ethyl, isopropyl, cyclopropyl, cyclobutyl, CF3 or CH2CF3; or R1 is ethyl, isopropyl, cyclopropyl, CF3 or CH2CF3;

[0136] R2 is F;

[0137] R3 is H;

[0138] R4 is OH;

[0139] Or R3 and R4 are combined with the benzene ring to which they are attached to form an indazole group as shown below;

[0140]

[0141] R5 is H;

[0142] R6 is H or F;

[0143] X is C-R7, wherein R7 is H or F;

[0144] R8 is CF3, CF2CF3 CH(CH3)2 or SF5; or R8 is CF3, CF2CF3 or SF5;

[0145] R9 is H; and

[0146] R 10 It's H.

[0147] In an even more preferred aspect of the first embodiment, the present invention provides a compound of formula (1a), (1a'), (1b), (1b'), (1c) or (1d), or a pharmaceutically acceptable salt or solvate thereof,

[0148] in:

[0149] R1 is ethyl, isopropyl, cyclopropyl, CF3 or CH2CF3;

[0150] R2 to R6 are selected to provide the following structure:

[0151] and

[0152] R7 and R8 are selected to provide the following structure:

[0153]

[0154] Or select R7 and R8 to provide the following structure:

[0155]

[0156] The following compounds represent specific embodiments of the present invention:

[0157] Example 1: 2-methoxy-5-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0158] Example 2: 4-Fluoro-5-{6-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0159] Example 3: 3-Fluoro-4-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenoxyphosphonic acid

[0160] Example 4: 4-[2-methyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0161] Example 5: 2-methoxy-4-(2-methyl-6-(3-(trifluoromethyl)phenyl)imidazo[1,2-a]pyrazin-3-yl)

[0162] Example 6: 3-Fluoro-4-[2-methyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0163] Example 7: 2-methoxy-5-[2-ethyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0164] Example 8: 3-Fluoro-4-[2-ethyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0165] Example 9: 3-Fluoro-4-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0166] Example 10: 3-Fluoro-4-[2-methyl-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0167] Example 11: 3-Fluoro-4-[2-difluoromethyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0168] Example 12: 3-Fluoro-4-[2-trifluoromethyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0169] Example 13: 2-methoxy-5-[2-cyclopropyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0170] Example 14: 3-Fluoro-4-[2-cyclopropyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0171] Example 15: 3,5-difluoro-4-[2-methyl-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0172] Example 16: 3,5-difluoro-4-[2-methyl-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0173] Example 17: 3,5-difluoro-4-[2-(propan-2-yl)-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0174] Example 18: 2-methoxy-5-[2-(propan-1-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0175] Example 19: 3,5-difluoro-4-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0176] Example 20: 4-(2-isopropyl-6-(3-(trifluoromethyl)phenyl)imidazo[1,2-a]pyrazin-3-yl)-3-methoxyphenol

[0177] Example 21: 4-Fluoro-5-{2-propan-2-yl-6-[3-trifluoromethylphenyl]imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0178] Example 22: 7-methoxy-5-{2-(propan-2-yl)-6-[3-trifluoromethylphenyl]imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0179] Example 23: 2-methoxy-5-(2-methyl-5-(3-(trifluoromethyl)phenyl)pyrazolo[1,5-c]pyrimidin-3-yl)phenol

[0180] Example 24: 3,5-difluoro-4-(2-isopropyl-5-(3-(trifluoromethyl)phenyl)pyrazolo[1,5-c]pyrimidin-3-yl)phenol

[0181] Example 25: 5-(2-isopropyl-5-(3-(trifluoromethyl)phenyl)pyrazolo[1,5-c]pyrimidin-3-yl)-2-methoxyphenol

[0182] Example 26: 2-methoxy-5-[2-(cyclopropylmethyl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0183] Example 27: 2-methoxy-5-[2-(propan-2-yl)-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0184] Example 28: 2-methoxy-5-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenoxyphosphonic acid

[0185] Example 29: 4-Fluoro-5-{2-trifluoromethyl-6-[3-(pentafluoroethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0186] Example 30: 2-methoxy-5-[2-(trifluoromethyl)-6-[3-(pentafluoroethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0187] Example 31: 3,5-difluoro-4-[2-methyl-6-[3-(pentafluorosulfanyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0188] Example 32: 4-Fluoro-5-{2-cyclopropyl-6-[(4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0189] Example 33: 3,5-difluoro-4-[2-(1-methyl-cyclopropyl-1-yl)-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0190] Example 34: 4-(2-cyclopropyl-6-(4-fluoro-3-(trifluoromethyl)phenyl)imidazo[1,2-a]pyrazin-3-yl)-3,5-difluorophenol

[0191] Example 35: 4-(2-cyclobutyl-6-(4-fluoro-3-(trifluoromethyl)phenyl)imidazo[1,2-a]pyrazin-3-yl)-3,5-difluorophenol

[0192] Example 36: 3,5-difluoro-4-[2-ethyl-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0193] Example 37: 4-Fluoro-5-{2-ethyl-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0194] Example 38: 3,5-difluoro-4-(6-(4-fluoro-3-(trifluoromethyl)phenyl)-2-(2,2,2-trifluoroethyl)imidazo[1,2-a]pyrazin-3-yl)phenol

[0195] Example 39: 3,5-difluoro-4-[2-(propan-2-yl)-6-[3-(pentafluorosulfanyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0196] Example 40: 3,5-difluoro-4-{6-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)imidazo[1,2-a]pyrazin-3-yl}phenoxyphosphonic acid

[0197] Example 41: 3,5-difluoro-4-{6-[4-fluoro-3-(trifluoromethyl)phenyl]-2-methyl-imidazo[1,2-a]pyrazin-3-yl}phenoxyphosphonic acid

[0198] Example 42: 3,5-difluoro-4-(5-(4-fluoro-3-(trifluoromethyl)phenyl)-2-methylpyrazolo[1,5-c]pyrimidin-3-yl)phenol

[0199] Example 43: 2-Cyclopropyl-3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-(trifluoromethyl)phenyl)imidazo[1,2-a]pyrazine

[0200] Example 44: 4-[2-Cyclopropyl-6-(4-fluoro-3-pentafluoroethyl-phenyl)-imidazo[1,2-a]pyrazin-3-yl]-3,5-difluoro-phenol

[0201] Example 45: 4-{2-ethyl-6-[4-fluoro-3-(1,1,2,2,2-pentafluoroethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl}-3,5-difluorophenol

[0202] Example 46: 2-Cyclopropyl-3-(4-fluoro-1H-indazol-5-yl)-6-(3-(pentafluoro-λ6-sulfanyl)phenyl)imidazo[1,2-a]pyrazine

[0203] Example 47: 3,5-difluoro-4-(5-(4-fluoro-3-(trifluoromethyl)phenyl)-2-isopropylpyrazolo[1,5-c]pyrimidin-3-yl)phenol

[0204] Example 48: 4-(2-ethyl-5-(4-fluoro-3-(trifluoromethyl)phenyl)pyrazolo[1,5-c]pyrimidin-3-yl)-3,5-difluorophenol

[0205] Example 49: 3,5-difluoro-4-[2-methyl-6-[3-(pentafluoroethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0206] Example 50: 3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-trifluoromethylphenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0207] Example 51: 2-Isopropyl-3-(3-methyl-1H-indazol-5-yl)-6-(3-trifluoromethyl-phenyl)-imidazo[1,2-a]pyrazine

[0208] Example 52: 4-[2-ethyl-6-(3-pentafluoroethyl-phenyl)-imidazo[1,2-a]pyrazin-3-yl]-3,5-difluoro-phenol

[0209] Example 53: 3,5-difluoro-4-[6-(4-fluoro-3-pentafluoroethyl-phenyl)-2-methyl-imidazo[1,2-a]pyrazin-3-yl]-phenol

[0210] Example 54: 5-{2-cyclopropyl-6-[4-fluoro-3-(1,1,2,2,2-pentafluoroethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl}-4-fluoro-1H-indazole

[0211] Example 55: 4-Fluoro-5-[5-(4-fluoro-3-trifluoromethyl-phenyl)-2-isopropylpyrazolo[1,5-a]pyridin-3-yl]-1H-indazole

[0212] Example 56: 4-[2-Cyclopropyl-6-(4-fluoro-3-pentafluorosulfanyl-phenyl)-imidazo[1,2-a]pyrazin-3-yl]-3,5-difluoro-phenol

[0213] Example 57: 2-Cyclopropyl-3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-pentafluorosulfanyl-phenyl)-imidazo[1,2-a]pyrazine

[0214] Example 58: 3-(4-Fluoro-1H-indazol-5-yl)-5-(4-fluoro-3-pentafluoroethyl-phenyl)-2-isopropyl-pyrazolo[1,5-c]pyrimidine

[0215] Example 59: 2-Cyclopropyl-3-(4-fluoro-1H-indazol-5-yl)-5-(4-fluoro-3-pentafluoroethyl-phenyl)-pyrazolo[1,5-c]pyrimidine

[0216] Example 60: 4-[2-Cyclopropyl-5-(4-fluoro-3-trifluoromethyl-phenyl)-pyrazolo[1,5-c]pyrimidin-3-yl]-3,5-difluoro-phenol

[0217] Example 61: 3-(4-Fluoro-1H-indazol-5-yl)-5-(4-fluoro-3-trifluoromethyl-phenyl)-2-isopropyl-pyrazolo[1,5-c]pyrimidine

[0218] Example 62: Mono-{4-[2-cyclopropyl-6-(4-fluoro-3-trifluoromethyl-phenyl)-imidazo[1,2-a]pyrazin-3-yl]-3,5-difluoro-phenyl}phosphate

[0219] Example 63: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-pentafluoroethyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0220] Example 64: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-pentafluorosulfanyl-phenyl)-2-methyl-imidazo[1,2-a]pyrazine

[0221] Example 65: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-pentafluorosulfanyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0222] Example 66: 3-(4-Fluoro-1H-indazol-5-yl)-6-(3-isopropyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0223] Example 67: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0224] Example 68: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-pentafluorosulfanyl-phenyl)-2-isopropyl-imidazo[1,2-a]pyrazine

[0225] Example 69: 3-(4-Fluoro-1H-indazol-5-yl)-6-[4-fluoro-3-(2,2,2-trifluoro-ethyl)-phenyl]-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0226] Example 70: 3-(4-Fluoro-1H-indazol-5-yl)-2-trifluoromethyl-6-(3-trifluoromethyl-phenyl)-imidazo[1,2-a]pyrazine

[0227] Example 71: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-trifluoromethoxy-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0228] Example 72: 3-(4-Fluoro-1H-indazol-5-yl)-6-(3-trifluoromethoxy-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0229] Example 73: 6-(3-Bromo-phenyl)-3-(4-fluoro-1H-indazol-5-yl)-2-isopropyl-imidazo[1,2-a]pyrazine

[0230] Example 74: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropyl-phenyl)-2-isopropyl-imidazo[1,2-a]pyrazine

[0231] Example 75: 2-Ethyl-3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropyl-phenyl)-imidazo[1,2-a]pyrazine

[0232] Example 76: 2-Cyclobutyl-3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-trifluoromethyl-phenyl)-imidazo[1,2-a]pyrazine

[0233] Example 77: 2-Cyclobutyl-3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropyl-phenyl)-imidazo[1,2-a]pyrazine

[0234] Example 78: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-prop-2-ynyloxy-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0235] Example 79: 2-Cyclopropyl-3-(4-fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropyl-phenyl)-imidazo[1,2-a]pyrazine

[0236] Example 80: 4-[2-Cyclopropyl-6-(4-fluoro-3-isopropyl-phenyl)-imidazo[1,2-a]pyrazin-3-yl]-3,5-difluoro-phenol

[0237] Example 81: 3-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropoxy-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0238] Example 82: 6-(3-cyclobutyl-4-fluoro-phenyl)-3-(4-fluoro-1H-indazol-5-yl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0239] Example 83: 3-(4-chloro-1H-indazol-5-yl)-6-(4-fluoro-3-isopropyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0240] Example 84: 6-(3-Cyclopropyl-4-fluoro-phenyl)-3-(4-fluoro-1H-indazol-5-yl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0241] Example 85: 6-(3-Bromo-4-fluoro-phenyl)-3-(4-fluoro-1H-indazol-5-yl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0242] Example 86: 3-(4-Fluoro-1H-indazol-5-yl)-6-(3-isopropoxy-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0243] Example 87: 3-(4-Fluoro-1H-indazol-5-yl)-6-(2-isopropyl-pyridin-4-yl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0244] Example 88: 3-(4-Fluoro-1H-indazol-5-yl)-2-trifluoromethyl-6-(2-trifluoromethyl-pyridin-4-yl)-imidazo[1,2-a]pyrazine

[0245] Example 89: 3,5-Difluoro-4-[2-(4-fluoro-3-trifluoromethyl-phenyl)-8-isopropyl-purin-9-yl]-phenol

[0246] Example 90: 3-Fluoro-4-[8-(propan-2-yl)-2-[3-(trifluoromethyl)phenyl]-9H-purin-9-yl]phenol

[0247] C. Composition

[0248] The compounds of the invention intended for pharmaceutical use may be administered alone, or in combination with one or more other compounds of the invention, or in combination with one or more other drugs (or as any combination thereof). Typically, they will be administered as a formulation combined with one or more pharmaceutically acceptable excipients. Therefore, the present invention also relates to a pharmaceutical composition comprising (i) a therapeutically effective amount of a compound of formula (1a), (1b), (1c) or (1d) as defined above, or a pharmaceutically acceptable salt or solvate thereof; and (ii) a pharmaceutically acceptable excipient.

[0249] Pharmaceutical compositions suitable for delivering the compounds of the present invention and methods for their preparation will be apparent to those skilled in the art. Such compositions and methods for their preparation can be found, for example, in "Remington's Pharmaceutical Sciences", 19th edition (Mack Publishing Company, 1995).

[0250] D. How to use

[0251] The present invention also relates to compounds of formula (1a), (1b), (1c) and (1d) as defined above or pharmaceutically acceptable salts or solvates thereof for use in treatment, in particular for the treatment of schistosomiasis.

[0252] The present invention also relates to the use of the compounds of formula (1a), (1b), (1c) and (1d) as defined above or their pharmaceutically acceptable salts or solvates in the manufacture of a medicament for treating schistosomiasis.

[0253] The present invention also relates to a method for treating schistosomiasis, which comprises administering to a patient in need thereof a therapeutically effective amount of a compound of formula (1a), (1b), (1c) or (1d) as defined above, or a pharmaceutically acceptable salt or solvate thereof.

[0254] Of course, the amount of active ingredient required to achieve a therapeutic effect will vary with the specific compound, route of administration, subject being treated (including type, species, age, weight, sex and medical condition of the subject and renal and liver function of the subject), and the specific condition or disease being treated and its severity. A physician, veterinarian or clinician of ordinary skill can readily determine and prescribe the effective amount of the drug required to prevent, resist or retard the progression of the disorder.

[0255] E. General Synthesis Methods

[0256] Methods for synthesizing the compounds of the present invention are illustrated by the following schemes. The starting materials and reagents used to prepare these compounds are available from commercial suppliers or can be prepared by methods that are obvious to those skilled in the art.

[0257] General Method 1A

[0258] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R6 and X are defined according to the present invention, and R8 is CF3, CF2CF3 or CH(CH3)2. The method comprises reacting an appropriate 3-chloro or 3-bromo-imidazo[1,2-a]pyrazine with an appropriate arylboronic acid or arylpinacol borane under Suzuki conditions in the presence of a palladium catalyst.

[0259]

[0260] General Method 1B

[0261] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R6 and X are defined according to the present invention, and R8 is CF3 or CF2CF3. The method comprises reacting an appropriate 3-bromo-pyrazolo[1,5-c]pyrimidine with an appropriate aryl boronic acid or aryl pinacol borane under Suzuki conditions in the presence of a palladium catalyst.

[0262]

[0263] General Method 2

[0264] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R6 and X are defined according to the present invention, and R8 is CF2CF3 or SF5. The method comprises reacting an appropriate 6-bromo-imidazo[1,2-a]pyrazine with an appropriate aryl boronic acid or aryl pinacol borane under Suzuki conditions in the presence of a palladium catalyst.

[0265]

[0266] General Method 3A

[0267] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R6 and X are defined according to the present invention, and R8 is CF3, CF2CF3, CH(CH3)2, CH2CF3, OCF3, OCH(CH3)2, OCH2C≡CH, cPr, cBu or SF5. The method comprises reacting an appropriate 3-bromo or 3-chloro-imidazo[1,2-a]pyrazine with an appropriate THP-protected indazole pinacol borane under Suzuki conditions in the presence of a palladium catalyst. The THP group can be removed under acidic conditions, for example, using TFA or HCl in an alcohol solvent.

[0268]

[0269] General Method 3B

[0270] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R6 and X are defined according to the present invention, and R8 is CF3 or CF2CF3. The method comprises reacting an appropriate 3-bromo-pyrazolo[1,5-c]pyrimidine with an appropriate THP-protected indazole pinacol borane under Suzuki conditions in the presence of a palladium catalyst. The THP group can be removed under acidic conditions, for example using TFA or HCl in an alcohol solvent.

[0271]

[0272] General Method 3C

[0273] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R8 and X are defined according to the present invention. The method comprises reacting an appropriate 3-bromo-pyrazolo[1,5-c]pyridine with an appropriate THP-protected indazole pinacol borane under Suzuki conditions in the presence of a palladium catalyst. The THP group can be removed under acidic conditions, for example, using TFA or HCl in an alcohol solvent.

[0274]

[0275] General Methods 3D

[0276] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1-R8 and X are defined according to the present invention. The method comprises reacting an appropriate 3-iodo-imidazo[1,2-a]pyrazine with an appropriate THP-protected indazole pinacol borane under Suzuki conditions in the presence of a palladium catalyst. The THP group can be removed under acidic conditions, for example, using TFA or HCl in an alcohol solvent.

[0277]

[0278] General method 4

[0279] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1, R2, R5-R8 and X are defined according to the present invention, and R3 or R4 is OPO(OH)OH. The method comprises reacting an appropriate hydroxyphenylimidazo[1,2-a]pyrazine with phosphorus oxychloride in pyridine and then treating the crude product with acetone / water.

[0280]

[0281] General Method 5

[0282] The present invention also provides a method for preparing a schistosome growth inhibitor, wherein R1, R2, R6, R8 and X are defined according to the present invention. The method comprises coupling an appropriate chloropyrimidine and an arylboronic acid to obtain an intermediate, reducing the intermediate with Raney Ni, reacting the obtained diamine with an alkyl aldehyde to obtain an intermediate, arylizing the intermediate to a purine derivative, and finally deprotecting the intermediate under acidic conditions.

[0283]

[0284] F. Synthesis of Example Compounds

[0285] General experimental details

[0286] LC-MS

[0287] The compound to be purified under basic conditions was purified on an LC-MS system equipped with a YMC Actus Triart C18 5 μm (20×250 mm) column or a Gemini NX 5 μm C18 (100×30 mm) column using a gradient elution of acetonitrile in water containing 20 mM ammonium bicarbonate (10%-45% over 30 min, then 95% acetonitrile for 2 min).

[0288] UPLC

[0289] Method A: Formic acid / ammonium acetate (run time 3 min-UPLC) (3 min)

[0290] Column - Restek Ultra AQ C18 (30x2.1mm, 3u), (mobile phase: 98% [0.05% modifier in water] and 2% [CH3CN] for 0.75min, then changed to 90% [0.05% modifier in water] and 10% [CH3CN] in 1.0min, then changed to 2% [0.05% modifier in water] and 98% [CH3CN] in 2.0min, the mobile phase composition was maintained for up to 2.25min, and finally returned to the initial condition in 3.0min). Flow rate = 1.5ml / min

[0291] Method E: (overall - 5min)

[0292] Column - Zorbax C18 (50x4.6mm, 5u, 130A), (mobile phase: changed from 90% [10mM NH4OAc aqueous solution] and 10% [CH3CN] to 70% [10mM NH4OAc aqueous solution] and 30% [CH3CN] in 1.5min, then changed to 10% [10mM NH4OAc aqueous solution] and 90% [CH3CN] in 3.0min, the mobile phase composition was maintained for up to 4.0min, and finally returned to the initial conditions in 5.0min). Flow rate = 1.2ml / min.

[0293] NMR

[0294] Unless otherwise stated for residual solvent signals, they were recorded at room temperature on 400 MHz and 101 MHz instruments, respectively. 1 H NMR and 13 C spectra. Data are presented as follows: chemical shift (ppm), integration, multiplicity (br = broad, app = apparent, s = singlet, d = doublet, t = triplet, q = quartet, p = quintet, m = multiplet) and coupling constant (Hz).

[0295] Starting material preparation

[0296] All starting materials used to prepare intermediates and example compounds were obtained from commercial sources or using literature procedures, with the exception of the following compounds.

[0297] Starting material 1

[0298] 4-Fluoro-1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indazole

[0299] To a stirred solution of 5-bromo-4-fluoro-1-(oxacyclohexane-2-yl)-1H-indazole (800mg, 2.7mmol) in dioxane (20mL) was added bis(pinacol)diboron (1.36g, 5.3mmol) and potassium acetate (787mg, 8.0mmol) in a sealed tube, and the resulting mixture was stirred and degassed with argon for 5min. Pd(dppf)Cl2.DCM (218mg, 0.27mmol) was then added and the resulting mixture was refluxed at 110°C for 6h. After completion, the reaction mixture was evaporated under reduced pressure. The residue was suspended in water and extracted with ethyl acetate. The combined organic layers were dried over anhydrous Na2SO4 and evaporated under reduced pressure. The crude compound was purified by column chromatography using silica gel, eluted with 0-10% EtOAc in hexane to give the title compound (900mg, 97%) as a yellow oil. UPLC rt 1.9min MH + 347. 1 H NMR(400MHz, CDCl3)δ8.09(s,1H),7.67(dd,1H),7.31(d,1H),5.69(dd,1H),4.01(d,1H),3 .73(t,1H),2.53(m,1H),2.12(m,1H),2.05(m,1H),1.75(m,2H),1.68(m,1H),1.40(s,12H).

[0300] Starting material 2

[0301] 2-(4-Fluoro-3-pentafluoroethyl-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane)

[0302] To a stirred solution of 4-bromo-1-fluoro-2-pentafluoroethyl-benzene (1 g, 3.4 mmol) in 1,4-dioxane (25 ml) was added bispinacolatodiborane (1.7 g, 6.8 mmol) followed by potassium acetate (1 g, 10.2 mmol). The reaction mixture was deoxygenated with argon and then [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) chloride, complexed with dichloromethane (0.28 g, 0.34 mmol) was added to the reaction mixture and the reaction mixture was stirred at 90 °C under nitrogen for 16 h. After complete consumption of the starting material (monitored by TLC), the reaction mixture was filtered, the celite bed was discarded to remove the catalyst, the mother liquor was evaporated under reduced pressure, the residue was diluted with ethyl acetate, washed successively with water and brine, the organic layer was dried over sodium sulfate and evaporated under reduced pressure to give the product which was used without further purification.

[0303] Starting material 3

[0304] 4-Fluoro-1-(tetrahydro-pyran-2-yl)-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indazole

[0305] Step 14-Bromo-3-fluoro-2-methyl-aniline

[0306] N-bromosuccinimide (23g, 132mmol) was added in batches to a solution of 3-fluoro-2-methylaniline (15.0g, 120mmol) in ACN (300.0mL) at 10°C. The reaction mixture was stirred for 3h at ambient temperature and evaporated under reduced pressure. The reaction mixture was diluted with saturated Na2S2O3 (100.0mL) at 10°C and extracted with EtOAc (2X 100mL). The combined organic layers were washed with brine, dried over anhydrous Na2SO4 and evaporated under reduced pressure to obtain the desired crude product, which was purified by column chromatography (100-200 mesh silica gel, eluent: 15% ethyl acetate in hexane) to obtain the title compound (15g, 61%) as a brown solid. LCMS rt 3.27min MH+204. 1H NMR (400MHz, DMSO-d6) δ7.09 (t, J = 8.2, 1H), 6.40 (d, J = 8.52, 1H), 1.98 (s, 3H).

[0307] Step 24-Bromo-3-fluoro-2-methyl-aniline

[0308] To the acetic acid (200mL) solution of 4-bromo-3-fluoro-2-methyl-aniline (15.0g, 73.5mmol) stirred at 10 ℃, sodium nitrite (10g, 147mmol) was added in batches, and the reaction mixture was stirred at rt for 16h. After completion, at -10 ℃, under vigorous stirring, the NaOH aqueous solution (50%) was added dropwise to the reaction mixture until pH was ~7-8. The mixture was then extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated under reduced pressure to obtain a crude compound, which was purified by silica gel column chromatography (0-40% EtOAc in hexane) to obtain the title compound (10g, 63%) as a white solid. LCMSrt 3.03min MH+214. 1H NMR (400MHz, CDCl3) δ 10.44 (brs, 1H), 8.14 (s, 1H), 7.49-7.45 (m, 1H), 7.19 (d, J = 8.76, 1H).

[0309] Step 35-Bromo-4-fluoro-1-(tetrahydro-pyran-2-yl)-1H-indazole

[0310] 3,4-dihydropyran (11.7 g, 139 mmol) was added to a stirred solution of 5-bromo-4-fluoro-1H-indazole (10.0 g, 46 mmol) in dichloromethane (300.0 mL), followed by PTSA (800 mg, 4.6 mmol), and the reaction mixture was stirred for 12 h at ambient temperature under nitrogen. After completion, the reaction mixture was diluted with DCM, washed with saturated NaHCO3 solution and brine in sequence, and the combined organic layers were dried over anhydrous Na2SO4 and evaporated under reduced pressure to give a crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent: 5% ethyl acetate in hexane) to give the title compound (8 g, 57%) as an off-white solid.

[0311] LCMSrt 3.83min MH+299.1H NMR (400MHz, CDCl3) δ8.05 (s, 1H), 7.46-7.43 (m, 1H), 7.28 (d, J = 8.84, 1H), 5.69-5.67 (m, 1H), 3.99-3.86(m,1H),3.74-3.70(m,1H),2.53-2.45(m,1H),2.13-2.09(m,2H),1.86-1.71(m,4H).

[0312] Step 4 4-Fluoro-1-(tetrahydro-pyran-2-yl)-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indazole

[0313] To a stirred solution of 5-bromo-4-fluoro-1-(tetrahydro-pyran-2-yl)-1H-indazole (8 g, 26.7 mmol) in 1,4-dioxane (200 ml) was added bis-pinacol boronate (13.6 g, 53.5 mmol) followed by potassium acetate (7.8 g, 80.3 mmol). The reaction mixture was deoxygenated with argon, and then [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) chloride was added to the reaction mixture, complexed with dichloromethane (2.2 g, 2.67 mmol), and the reaction mixture was stirred at 90° C. under nitrogen for 16 h. The solvent was evaporated under reduced pressure, and the residue was diluted with ethyl acetate and filtered through a celite bed. The filtrate was then washed with water and brine in sequence. The organic layer was dried over sodium sulfate and evaporated under reduced pressure to give a crude product, which was purified by column chromatography (100-200 mesh silica gel, eluent: 5% ethyl acetate in hexane) to give the title compound (6 g, 64%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 8.08 (s, 1H), 7.68-7.65 (m, 1H), 7.31 (d, J = 8.56, 1H), 5.70-5.67 (m, 1H), 4.02-3.99 (m, 1H), 3.76-3.70 (m, 1H), 2.54-2.52 (m, 1H), 2.16-2.03 (m, 2H), 1.77-1.65 (m, 4H), 1.36 (s, 12H).

[0314] Preparation of Intermediate 1-61

[0315] Intermediate 1

[0316] 3-Bromo-2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine

[0317] Step 16-Bromo-2-(propan-2-yl)imidazo[1,2-a]pyrazine

[0318] 2-Amino-5-bromopyrazine (10 g, 57 mmol) and 1-bromo-3-methyl-butan-2-one (20 mL) were dissolved in acetonitrile (50 mL) and heated in a sealed tube at 100°C for 3 days. The reaction was quenched with sodium bicarbonate solution, filtered and extracted with ethyl acetate, the organic layer was dried over sodium sulfate and concentrated to give a brown liquid, which was purified by column chromatography (100-200 mesh silica gel, eluent; 50% ethyl acetate in DCM) to give the title compound (3.5 g, 25%) as a brown semi-solid. UPLC rt 2.7 min MH + 242. 1H NMR (400MHz, DMSO-d6) δ8.79(s,1H),8.18(s,1H),7.45(s,1H),3.15(h,1H),1.36(d,6H).

[0319] Step 2 2-(Propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine

[0320] A mixture of 6-bromo-2-(propan-2-yl)imidazo[1,2-a]pyrazine (2.0 g, 8.3 mmol) and 3-(trifluoromethyl)phenylboronic acid (1.9 g, 10 mmol) was dissolved in dioxane:H2O (3:1, 20 mL) and treated with K3PO4 (5.3 g, 25 mmol). The mixture was degassed for 20-30 min, treated with Pd-dppf-DCM complex (2.0 g, 2.5 mmol) and heated at 90 °C for 16 h. Upon completion, the reaction was quenched with water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated to give the crude compound, which was purified by chromatography (100-200 mesh silica gel, eluent: 10% ethyl acetate in DCM) to give the title compound (2.3 g, 90%). UPLC rt 3.4 min MH + 306. 1 H NMR (400MHz, DMSO-d6) δ9.12(s,1H),8.43(s,1H),8.19(s,1H),8.10(d,1H),7.65(d,1H),7.59(t,1H),7.54(s,1H),3.21(h,1H),1.40(d,6H).

[0321] Step 33-Bromo-2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine

[0322] 2-(Propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine (2.3 g, 7.5 mmol) was dissolved in DCE (25 mL) and treated with N-bromosuccinimide (1.6 g, 9.1 mmol), and the mixture was heated at 85-90° C. for 8 h. The reaction mixture was concentrated and the crude product was purified by combiflash chromatography to give the title compound as a brown solid (1.5 g, 52%). UPLC rt 4.0 min MH + 386. 1H NMR (400MHz, DMSO-d6) δ9.07(s,1H),8.38(s,1H),8.25(s,1H),8.15(d,1H),7.68(d,1H),7.62(t,1H),3.30(h,1H),1.40(d,6H).

[0323] Intermediate 37

[0324] 3-Chloro-6-(4-fluoro-3-pentafluoroethyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0325] Step 1:

[0326] 6-Bromo-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0327] 3-bromo-1,1,1-trifluoroacetone (3g, 3mmol) was added to a stirred solution of 2-amino-5-bromo-pyrazine (2g, 11.5mmol) in isopropanol (60ml), and the mixture was stirred at 90°C for 72h. After complete consumption of the starting material (monitored by TLC and LCMS), the solvent was evaporated under reduced pressure, the residue was diluted with ethyl acetate, alkalized with saturated bicarbonate solution, and filtered with a diatomaceous earth bed. The aqueous portion was discarded, the organic portion was washed with saturated sodium bicarbonate solution and brine in turn, the organic layer was dried over sodium sulfate, and the crude compound was evaporated under reduced pressure, which was purified by column chromatography (100-200 mesh silica gel, eluent: 20% ethyl acetate in DCM solution) to give the title compound (1g, 32.7%) as a brown solid. LCMS rt 2.87min MH+266. 1H NMR (400MHz, DMSO-d6) δ9.13(s,1H)8.99(s,1H),8.64(s,1H).

[0328] Step-2:

[0329] 6-Bromo-3-chloro-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0330] N-chlorosuccinimide (753 mg, 5.63 mmol) was added to a stirred solution of 6-bromo-2-trifluoromethyl-imidazo[1,2-a]pyrazine (1 g, 3.75 mmol) in anhydrous DMF (25 ml), and the reaction mixture was stirred at 90 ° C for 24 h. After complete consumption of the starting material (monitored by TLC and LCMS), the reaction mixture was diluted with ethyl acetate, washed with water and brine in sequence. The organic portion was dried over sodium sulfate and evaporated under reduced pressure to give a crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent: 10% ethyl acetate in DCM) to give the title compound (900 mg, 79.7%) as a light brown solid.

[0331] LCMS rt 3.16min MH+301. 1H NMR (400MHz, DMSO-d6) δ9.17(s,1H)8.94(s,1H).

[0332] Step-3:

[0333] 3-Chloro-6-(4-fluoro-3-pentafluoroethyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0334] A mixture of 6-bromo-3-chloro-2-trifluoromethyl-imidazo[1,2-a]pyrazine (800 mg, 2.67 mmol) and 2-(4-fluoro-3-pentafluoroethyl-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane) (1 g, 2.93 mmol) was dissolved in 1,4-dioxane:H2O (4:1, 15 mL) and treated with K3PO4 (1.7 g, 8 mmol). The mixture was degassed for 20-30 min, treated with bis(diphenylphosphino)ferrocene]palladium(II) chloride, complexed with dichloromethane (217 mg, 0.27 mmol) and heated at 90 °C for 16 h. Upon completion, the reaction was quenched with water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated to give the crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent: 10% ethyl acetate in DCM) to give the title compound (700 mg, 60.5%). LCMS rt 4 min MH+434. 1HNMR (400 MHz, DMSO-d6) δ9.40 (s, 1H), 9.26 (s, 1H), 8.63 (br. s, 1H), 8.53 (d, J=5.08 Hz, 1H), 7.75-7.70 (m, 1H).

[0335] Intermediates 2-4, 6-9, 12-14, 16-20, 23-24, 28-29, 30-31, 33, 38-61

[0336] Prepared using analogous methods to Intermediate 1 or 37 from the appropriate halo ketone and boronic acid or boronic ester.

[0337] Intermediate 5

[0338] Prepared by modifying the pathway of the above intermediate using the following scheme.

[0339]

[0340] Intermediates 15, 21 and 25

[0341] Prepared from the appropriate 3-iodoimidazo[1,2-a]pyrazine using the following method

[0342] Intermediate 15

[0343] 4-{6-bromo-2-methylimidazo[1,2-a]pyrazin-3-yl}-3,5-difluorophenol

[0344] Step 16-Bromo-2-methylimidazo[1,2-a]pyrazine

[0345] 2-Amino-5-bromopyrazine (10 g, 57 mmol) and 1-bromo-2,2-dimethoxy-propane (15 g) were dissolved in IPA (30 mL) and heated in a sealed tube at 100° C. for 3 days. The reaction was quenched with sodium bicarbonate solution, filtered and extracted with ethyl acetate; the organic layer was dried over sodium sulfate and concentrated to give a brown solid, which was used in the next step without further purification.

[0346] Step 26-Bromo-3-iodo-2-methyl-imidazo[1,2-a]pyrazine

[0347] N-iodosuccinimide (3.82 g, 16.98 mmol) was added to a well-stirred solution of 6-bromo-2-methylimidazo[1,2-a]pyrazine (3 g, 14.15 mmol) in DMF (15 ml), and the reaction mixture was stirred at 80 ° C for 12 h under nitrogen. After complete consumption of SM (monitored by LCMS), the reaction mixture was diluted with ethyl acetate, washed with water and brine, dried over sodium sulfate and evaporated under reduced pressure to give the crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent; 20% ethyl acetate in hexane) to give the title compound as a light yellow solid [1.5 g, 31% (after two steps)]. LCMS rt 2.89 min MH + 338. 1 H NMR (400MHz, DMSO-d6) δ8.74(s,1H),8.49(s,1H),2.44(s,3H).

[0348] Step 34-{6-bromo-2-methylimidazo[1,2-a]pyrazin-3-yl}-3,5-difluorophenol

[0349] A mixture of 6-bromo-3-iodo-2-methyl-imidazo[1,2-a]pyrazine (120 mg, 0.355 mmol) and 2,6-difluoro-4-hydroxyphenylboronic acid (61.8 mg, 0.355 mmol) was dissolved in THF:H2O (3:1, 4 mL) and treated with KF (62 mg, 1.065 mmol). The mixture was degassed for 20-30 min, treated with bis(tri-tert-butylphosphine)palladium(0) (18 mg, 0.036 mmol), and heated at 120 ° C for 1 h under microwave irradiation (200 watts). After completion, the reaction was quenched with water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated to give a crude compound, which was used for the preparation of Example 31 without further purification.

[0350] Intermediate 11

[0351] 3-Bromo-2-(propan-2-yl)-5-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-c]pyrimidine

[0352] Step 1

[0353] [4-Bromo-3-(propan-2-yl)-1H-pyrazol-5-yl]methanol

[0354] To a stirred solution of ethyl 4-bromo-3-(propan-2-yl)-1H-pyrazole-5-carboxylate (400 mg, 1.5 mmol) in THF (4 mL) was added 2.5 M LAH (lithium aluminum hydride) in THF (2.5 M in THF, 87 μL, 2.3 mmol) at 0°C and stirred for 3 h. The reaction was then quenched by saturated Na2SO4 solution, filtered through celite, and evaporated under reduced pressure to give the title compound (290 mg, 86%). UPLC rt 3.1 min MH + 261. 1 H NMR (400MHz, DMSO-d6) δ12.79(s,1H),4.95(br.s,1H),4.37(s,2H),2.94(m,1H),1.21(d,6H).

[0355] Step 24-Bromo-5-(bromomethyl)-3-(propan-2-yl)-1H-pyrazole

[0356] To ice-cold [4-bromo-3-(propan-2-yl)-1H-pyrazol-5-yl]methanol (280 mg, 1.28 mmol) was added SOBr2 (7 mL) and the mixture was heated at 40°C for 2 h. The volatiles were removed in vacuo and the residue was triturated with hexanes to give the title compound as a pale yellow solid HBr salt (300 mg, 83%) UPLC rt 2.5 min MH + 283. 1 H NMR (400MHz, DMSO-d6) δ4.53 (s, 2H), 2.98 (m, 1H), 1.22 (d, 6H).

[0357] Step 3 3-Bromo-2-(propan-2-yl)-5-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-c]pyrimidine

[0358] 1-(3-trifluoromethylphenyl)-1-tosylmethyl isocyanide (120 mg, 0.36 mmol) and benzyltriethylammonium chloride (16 mg, 0.07 mmol) were added to a solution of 4-bromo-5-(bromomethyl)-3-(propan-2-yl)-1H-pyrazole (100 mg, 0.36 mmol) in DCM (2 mL) at -10 ° C, and then a solution of 30%-NaOH in water (2 mL) was added dropwise. The resulting reaction mixture was kept at -10 ° C for 3 h. The mixture was extracted into DCM, the organic layer was dried and concentrated in vacuo to give a crude product. The crude product was chromatographed on a silica gel column and eluted with 3%-EtOAc in hexane to give the title compound (30 mg, 22%) as a colorless solid. UPLC rt 2.7 min MH + 384. 1 H NMR (400MHz, DMSO-d6) δ9.59(s,1H),8.57(s,1H),8.54(d,1H),8.27(s,1H),7.82(d,1H),7.75(t,1H),3.25(h,1H),1.36(d,6H).

[0359] Intermediates 10, 22, 26, 27 and 34-36

[0360] Prepared from the appropriate pyrazole derivative and tosyl isocyanide. Prepare 1-(4-fluoro-3-trifluoromethylphenyl)-1-tosylmethyl isocyanide from (4-fluoro-3-trifluoromethylphenyl)methyl isocyanide and tosyl fluoride. Prepare 1-(4-fluoro-3-pentafluoroethylphenyl)-1-tosylmethyl isocyanide from (4-fluoro-3-pentafluoroethylphenyl)methyl isocyanide and tosyl fluoride.

[0361] Intermediate 32

[0362] 3-Bromo-2-(propan-2-yl)-5-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-a]pyridine

[0363]

[0364] Step-1

[0365] 2-[(Aminooxy)sulfonyl]-1,3,5-trimethylbenzene

[0366] TFA (160 ml) was added dropwise to tert-butyl [(mesitylenesulfonyl)oxy] carbamate 1 (40 g, 126.98 mmol) at 0 ° C, and the reaction mixture was stirred at this temperature for 1 h. The reaction mixture was slowly poured into ice water. The formed precipitate was filtered and washed thoroughly with water to remove traces of TFA to give 2- [(aminooxy)sulfonyl] -1,3,5-trimethylbenzene. The solid was dissolved in DCM (200 mL), and the solution was immediately used in the next step without further analysis.

[0367] Step-2

[0368] N-(1-amino{4}-pyridin-4-yl)carbamic acid tert-butyl ester.2,4,6-trimethylbenzene-1-sulfonic acid

[0369] To a solution of tert-butyl pyridin-4-yl-carbamate (2.30 g, 11.06 mmol) in DCM (30 mL) was added dropwise a solution of compound 2-[(aminooxy)sulfonyl]-1,3,5-trimethylbenzene in DCM (30 mL) at 0-5°C, and stirring was continued at this temperature for 2 h. The reaction mixture was concentrated under reduced pressure to give the target compound (2 g, 50%, two steps) as a brown gum. It was used in the next step without further purification. 1 H NMR (400MHz, DMSO-d6) δ10.93 (1H, br.s), 8.54 (2H, d, J = 6.9Hz), 7.85 (2H, d, J = 6.8Hz s), 6.73 (2H, s), 2.16 (3H, s), 1.51 (9H, s) [SO3 may not be seen in NMR H proton].

[0370] Step-3A

[0371] 4-Methyl-2-[(trifluoromethane)sulfonyloxy]pent-2-enoic acid ethyl ester

[0372] Ethyl isobutyryl acetate (5g, 31mmol) is added to a round-bottom flask and dissolved in toluene (150ml). The solution is cooled to 5°C-10°C (internal temperature) with an ice bath, and then a saturated LiOH aqueous solution (50mL, 240mmol) is added at a time. The obtained two-phase mixture is vigorously stirred at 5°C-10°C for ~5min, and then trifluoromethanesulfonic anhydride (13ml, 79mmol) is added dropwise at a rate to keep the internal temperature between 5°C-15°C. After the reaction is completed (as judged by TLC, usually <10min), the two-phase solution is diluted with water and each layer is separated. The aqueous layer is extracted with EtOAc. The combined organic layer is washed with water, brine, and dried over sodium sulfate. The organic layer is filtered and concentrated under reduced pressure to obtain the title compound (6.2g, 67%) as a colorless liquid.

[0373] 1 H NMR(400MHz,DMSO-d6)6.09(1H,s),4.19-4.13(2H,m),2.57-2.53(1H,m),1.24-1.14(9H,m)

[0374] Step-3B

[0375] Ethyl-4-methylpent-2-ynoate

[0376] To a stirred solution of ethyl 4-methyl-2-[(trifluoromethane)sulfonyloxy]pent-2-enoate (6.1 g, 21 mmol) in anhydrous THF (40 ml) was added triethylamine (4 ml, 29 mmol) and the reaction mixture was stirred at 80° C. for 16 h under nitrogen. The reaction mixture was then cooled to RT and evaporated under reduced pressure to give the title compound (2.5 g, 84.2%) as a yellow oil.

[0377] 1 H NMR(400MHz, DMSO-d6)4.16-4.10(1H,m),3.09-3.06(2H,m),d1.24-1.14(9H,m).

[0378] Step-3

[0379] Ethyl-{[(tert-butoxy)carbonyl]amino}-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate

[0380] To a stirred solution of tert-butyl N-(1-amino{4}-pyridin-4-yl)carbamate.2,4,6-trimethylbenzene-1-sulfonic acid (4.5 g, 11 mmol) in anhydrous DMF (12 ml) was added ethyl-4-methylpent-2-ynoate (1.5 g, 11 mmol) followed by potassium carbonate (3 g, 22 mmol) and the reaction mixture was stirred at room temperature under nitrogen for 16 h. After complete consumption of SM (monitored by LCMS), the reaction mixture was diluted with ethyl acetate, washed successively with water and brine, dried over sodium sulfate and evaporated under reduced pressure to give the crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent; 20% ethyl acetate in hexane) to give the title compound (1.6 g, 44%) as a brown solid. LCMS rt 4.20 min MH + 348. 1 HNMR(400MHz,DMSO-d6)δ9.93(s,1H).8.61(d,1H,J=7.44Hz),8.29(s,1H),7. 08(d,1H,J=7.44Hz)4.28-4.24(m,2H),3.68-3.65(m,1H),1.38-1.15(m,18H).

[0381] Step-4

[0382] Ethyl-5-amino-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate

[0383] To a stirred solution of ethyl-5-{[(tert-butoxy)carbonyl]amino}-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate (1.7 g, 4.8 mmol) in anhydrous DCM (12 ml) was added trifluoroacetic acid (3.6 ml) at 0°C and the reaction mixture was stirred at room temperature under nitrogen for 1 h. After complete consumption of SM (monitored by LCMS), the volatiles were evaporated under reduced pressure to give the crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent; 30% ethyl acetate in hexanes) to give the title compound (0.9 g, 75%) as an off-white solid. LCMS rt 3.34 min MH + 248. 1 H NMR (400MHz, DMSO-d6) δ8.30 (d, 1H, J = 7.32Hz), 6.90 (s, 1H), 6.41 (d, 1H, J = 7.4 4Hz),6.18(brs,2H),4.23-4.18(m,2H),3.63-3.56(m,1H),1.32-1.18(m,9H).

[0384] Step-5

[0385] Ethyl-5-iodo-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate

[0386] To a stirred solution of ethyl-5-amino-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate (800 mg, 3.23 mmol) in anhydrous acetonitrile (20 ml) at 0 °C was added tert-butyl nitrite (0.8 ml, 6.47 mmol) followed by potassium iodide (1.1 g, 6.47 mmol) and the reaction mixture was stirred at 70 °C under nitrogen for 16 h. After complete consumption of SM (monitored by LCMS), the reaction mixture was diluted with ethyl acetate, washed successively with water and brine, dried over sodium sulfate and evaporated under reduced pressure to give a crude compound, which was purified by silica gel column chromatography (100-200 mesh silica gel, eluent; 10% ethyl acetate in hexane) to give the title compound (550 mg, 47.41%) as a white solid. LCMS rt 2.78 min MH + 359 (nonpolar method). 1 H NMR (400MHz, DMSO-d6) δ.8.59 (d, 1H, J = 7.28Hz), 8.39 (s, 1H), 7.33 (d, 1H, J = 5.08Hz) 4.31-4.30 (m, 2H), 3.72-3.69 (m, 1H), 1.35-1.29 (m, 9H).

[0387] Step-6

[0388] Ethyl-5-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate

[0389] Ethyl-5-iodo-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate (0.25 g, 0.69 mmol) and 4-fluoro-3-trifluoromethylphenylboronic acid (0.21 g, 1.03 mmol) were dissolved in dioxane / water (4:1, 5 mL) and treated with K3PO4 (0.44 g, 2.07 mmol). The solution was degassed for 20-30 min, then PdCl2(dppf).DCM catalyst (57 mg, 0.07 mmol) was added, the reaction mixture was heated to 90°C for 16 h, cooled to room temperature, and partitioned between ethyl acetate and water. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (100-200 mesh silica gel, eluted with 10% ethyl acetate in hexane). The fractions containing the desired product were combined and evaporated under reduced pressure to give the title compound (240 mg, 85%) UPLC rt 1.94 min MH +395 (running for 3 minutes)

[0390] 1 H NMR(400MHz, DMSO-d6)δ8.91(d,J=7.36Hz,1H),8.26(s,1H)8.20-8.19(m,1H),8.13(d,J=6.64Hz,1H),7.70( t,J=10.16Hz,1H),7.52(dd,J=7.2Hz,1.02Hz,1H),4.36-4.30(m,2H),3.77-3.74(m,1H),1.38-1.32(m,9H).

[0391] Step-7

[0392] 5-[4-Fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)pyrazolo[1,5-a]pyridine

[0393] Ethyl-5-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)pyrazolo[1,5-a]pyridine-3-carboxylate (0.25 g, 0.63 mmol) was placed in concentrated HCl (60 ml), and the reaction mass was heated to reflux for 16 h. After complete consumption of SM (monitored by LCMS), the reaction mixture was cooled to 0 ° C, to which 2N NaOH was added dropwise until the pH was 8. It was then extracted with ethyl acetate, washed with water and brine in turn, dried over sodium sulfate and evaporated under reduced pressure to give a crude compound, which was purified by silica gel column chromatography (100-200 mesh silica gel, eluent; 10% ethyl acetate in hexane) to give the title compound (90 mg, 44%) as a white solid. UPLC rt 1.87 min (running 3 min) MH + 323.

[0394] 1 H NMR(400MHz, DMSO-d6)δ.8.66(d,J=7.04Hz,1H),8.16-8.10(m,2H)8.01(s,1H),7.65(t, J=9.64Hz,1H),7.21(d,J=7.08Hz,1H)6.49(s,1H),3.12-3.09(m,1H),1.34-1.30(m,6H).

[0395] Step-8

[0396] 3-Bromo-5-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)pyrazolo[1,5-a]pyridine

[0397] To a stirred solution of 5-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)pyrazolo[1,5-a]pyridine (86 mg, 0.26 mmol) in anhydrous acetonitrile (5 ml) was added N-bromosuccinimide (57 mg, 0.32 mmol) at 0° C. and the reaction mixture was stirred at 70° C. for 1 h under nitrogen. After complete consumption of SM (monitored by LCMS), the reaction mixture was diluted with ethyl acetate, washed sequentially with water and brine, dried over sodium sulfate and evaporated under reduced pressure to afford 89 mg of the title compound as a brown solid, which was used in the next step without further purification.

[0398] Intermediate 62

[0399] 9-[4-(Benzyloxy)-2,6-difluorophenyl]-8-(propan-2-yl)-2-[3-(trifluoromethyl)phenyl]-9H-purine was prepared from 2,4,6-trifluoronitrobenzene by a similar route to the product of Step 6 of Example 89 according to the following scheme:

[0400]

[0401] Preparation of Example 1-90

[0402] Example 1

[0403]

[0404] 2-Methoxy-5-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0405] 3-Bromo-2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine (1.5 g, 3.9 mmol) and 2-methoxy-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenol (1.46 g, 5.9 mmol) were dissolved in dioxane / water (4:1, 30 mL) and treated with K3PO4 (2.48 g, 11.7 mmol). The solution was degassed for 20-30 min, then Pd-118 catalyst (0.25 g, 0.39 mmol) was added, the reaction mixture was heated to 90°C for 16 h, cooled to room temperature, and partitioned between ethyl acetate and water. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (100-200 mesh silica gel, eluted with 20% ethyl acetate in DCM). The fractions containing the desired product were combined and evaporated under reduced pressure. The product was crystallized from methanol to give the title compound (600 mg, 36%) UPLC rt 1.9 min MH + 428.

[0406] 1 H NMR(400MHz,DMSO-d6)δ9.37(s,1H),9.15(s,1H),8.66(s,1H),8.36(s,1H),8.27(d,1H),7.75(d ,1H),7.70(d,1H),7.16(d,1H),7.03(d,1H),6.96(s,1H),3.87(s,3H),3.17(h,1H),1.28(d,6H).

[0407] Embodiment 4-9

[0408] Prepared using similar conditions from the corresponding 3-chloroimidazo[1,2-a]pyrazine

[0409] Example 2

[0410]

[0411] 4-Fluoro-5-{6-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)imidazo[1,2-a]pyrazin-3-yl}-1H-indazole

[0412] Step 1

[0413] 3-Bromo-2-(propan-2-yl)-6-[4-fluoro-3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine (500 mg, 1.24 mmol) and 4-fluoro-1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indazole (861 mg, 2.49 mmol) were dissolved in dioxane / water (4:1, 15 mL) and treated with K3PO4 (791 mg, 3.73 mmol). The solution was degassed with argon for 5 min, then tetrakis(triphenylphosphine palladium(0) catalyst (143 mg, 0.12 mmol) was added. The reaction vessel was sealed, the mixture was heated to 100°C for 3 h, cooled to room temperature, filtered through a celite bed to remove solids, then partitioned between ethyl acetate and water. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (100-200 mesh silica gel, eluted with 20% ethyl acetate in DCM). Fractions containing the desired product were combined and evaporated under reduced pressure, then triturated with ether and pentane to give the title compound 4-fluoro-5-{6-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)imidazo[1,2-a]pyrazin-3-yl}-1-(oxan-2-yl)-1H-indazole (600 mg, 89%) UPLC rt 4.27 min MH + 542.

[0414] Step 2

[0415] 4-Fluoro-5-{6-[4-fluoro-3-(trifluoromethyl)phenyl]-2-(propan-2-yl)imidazo[1,2-a]pyrazin-3-yl}-1-(oxan-2-yl)-1H-indazole (600 mg, 1.1 mmol) was dissolved in 30% TFA in DCM (4 mL) and stirred at room temperature for 2 h. The solvent was removed under reduced pressure, and the crude reaction mixture was diluted with dichloromethane, washed with sodium bicarbonate solution, water and brine in sequence, and the organic layer was dried over sodium sulfate and concentrated under reduced pressure to give a crude product, which was purified by reverse phase preparative HPLC to give the title compound (125 mg, 25%). UPLC rt 3.5 min MH + 458.

[0416] 1 H NMR(400MHz,DMSO-d6)δ13.85(s,1H),9.20(s,1H),8.76(s,1H),8.41(d,2H ),8.35(s,1H),7.61(t,1H),7.54(t,1H),7.50(t,1H),3.05(h,1H),1.27(dd 6H).

[0417] Example 3

[0418]

[0419] 3-Fluoro-4-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenoxyphosphonic acid

[0420] A solution of 3-fluoro-4-[2-(propan-2-yl)-6-[3-(trifluoromethyl)phenyl]imidazo[1,2-a]pyrazine-3-yl]phenol (Example 9 600mg, 1.45mmol) in DCM (10mL) was cooled to 0°C and treated with pyridine (4mL), followed by dropwise addition of a solution of phosphorus oxychloride (4mL) in DCM (10mL). The reaction mixture was stirred at RT for 5h. Two additional pyridines and POCl3 were added at 0°C to complete the reaction within 3 days. The reaction was quenched by dropwise addition of (1:1) acetone:water (100ml). The volatile solvent was then removed under reduced pressure. The resulting oil was dissolved in DMF and purified by reverse phase preparative HPLC to give the title compound (104mg, 15%).

[0421] UPLC rt 2.6min MH + 496.

[0422] 1H NMR(400MHz,DMSO-d6)δ9.17(s,1H),8.61(s,1H),8.39(s,1H),8.30(d,1H),7.72(d ,1H),7.67(t,1H),7.44(t,1H),7.32(d,1H),7.16(d,1H),3.17(h,1H),1.25(d,6H).

[0423] Embodiment 31

[0424]

[0425] 3,5-Difluoro-4-[2-methyl-6-[3-(pentafluorosulfanyl)phenyl]imidazo[1,2-a]pyrazin-3-yl]phenol

[0426] A mixture of 4-{6-bromo-2-methyl-imidazo[1,2-a]pyrazine-3-yl}-3,5-difluorophenol (40 mg, 0.118 mmol) and 3-(pentafluorosulfanyl)phenylboronic acid pinacol ester (58 mg, 0.176 mmol) was dissolved in dioxane / water (4:1, 5 mL) and treated with K3PO4 (49.8 mg, 0.235 mmol). The solution was degassed for 20-30 min, and then [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) chloride was added, complexed with dichloromethane (19 mg, 0.024 mmol). The reaction mixture was heated to 90°C for 16 h. The solvent was removed under reduced pressure, and the crude reaction mixture was then diluted with dichloromethane, washed with water and brine in sequence, and the organic layer was dried over sodium sulfate and concentrated under reduced pressure to give a crude product, which was purified by reverse phase preparative HPLC to give the title compound (4 mg, 7%).

[0427] UPLC rt 3.02min MH + 464. 1 H NMR(400MHz,DMSO-d6)δ9.12(s,1H),9.20(s,1H),8.33(s,1H),7.98(m,2H),7.77(d,1H),7.56(t,1H),6.68(d,1H),6.41(m,1H),2.47.(s,3H)

[0428] Embodiment 63

[0429]

[0430] Step 16-(4-Fluoro-3-pentafluoroethyl-phenyl)-3-[4-fluoro-1-(tetrahydro-pyran-2-yl)-1H-indazol-5-yl]-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0431] A mixture of 3-chloro-6-(4-fluoro-3-pentafluoroethyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine (620 mg, 1.43 mmol) and 4-fluoro-1-(tetrahydro-pyran-2-yl)-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indazole (1 g, 2.9 mmol) was dissolved in 1,4-dioxane:H2O (4:1, 15 mL) and treated with K3PO4 (0.91 g, 4.3 mmol). The mixture was degassed for 20-30 min, treated with palladium-tetrakis(triphenylphosphine) (331 mg, 0.28 mmol), and heated at 90 ° C for 16 h. After completion, the reaction was quenched with water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated to give the crude compound, which was purified by column chromatography (100-200 mesh silica gel, eluent: 10% ethyl acetate in DCM) to give the title compound (480 mg, 54.3%). LCMS rt 4.33 min MH+618. 1H NMR (400 MHz, DMSO-d6) δ 9.47 (s, 1H), 8.92-8.86 (m, 1H), 8.44-8.41 (m, 3H), 7.87-7.84 (m, 1H), 7.66-7.59 (m, 2H), 6.02 (d, J = 8.84 Hz, 1H), 3.96-3.80 (m, 1H), 2.08-1.62 (m, 5H).

[0432] Step 23-(4-Fluoro-1H-indazol-5-yl)-6-(4-fluoro-3-pentafluoroethyl-phenyl)-2-trifluoromethyl-imidazo[1,2-a]pyrazine

[0433] To a stirred solution of 6-(4-fluoro-3-pentafluoroethyl-phenyl)-3-[4-fluoro-1-(tetrahydro-pyran-2-yl)-1H-indazol-5-yl]-2-trifluoromethyl-imidazo[1,2-a]pyrazine (480 mg, 0.78 mmol) was added 20 ml of 30% TFA in DCM at 0°C and the reaction mixture was stirred at room temperature under nitrogen for 1 h. After complete consumption of the starting material (monitored by TLC and LCMS), the volatiles were evaporated under reduced pressure, the crude compound was diluted with dichloromethane, washed sequentially with sodium bicarbonate solution and brine, the organic layer was dried over sodium sulfate and evaporated under reduced pressure to give a crude product, which was purified by reverse phase preparative HPLC to give 150 mg of the title compound (150 mg, 36.2%). UPLC rt 1.96 min (running 3 min) MH+ 534. 1H NMR (400 MHz, DMSO-d6) δ 13.73 (s, 1H), 9.47 (s, 1H) 8.44-8.38 (m, 3H), 7.64-7.53 (m, 3H).

[0434] Embodiment 90

[0435]

[0436] Synthesis scheme:

[0437]

[0438] Step 14-Benzyloxy-2-fluoro-1-nitro-benzene (2)

[0439] To a stirred solution of 3-fluoro-4-nitro-phenol (3.8 g, 24.2 mmol) in DMF (30 mL) was added sodium hydride (1.74 g, 72.6 mmol) in portions at 0°C under argon, the reaction mass was stirred at the same temperature for 30 min, then benzyl bromide (3.18 ml, 26.6 mmol) was added dropwise to the reaction mass at 0°C, and the reaction mixture was stirred for another 4 h at room temperature. After complete conversion of the starting material, the reaction mixture was poured into crushed ice to precipitate a solid, which was collected by filtration to afford 5.5 g (91%) of the title compound as a yellow solid. LCMS rt 3.52min MH-245. 1H NMR (400MHz, CDCl3) δ 8.10-7.97 (m, 1H), 7.46-7.32 (m, 5H), 6.82-6.78 (m, 1H), 6.64-6.56 (m, 1H), 5.19-5.08 (m, 2H).

[0440] Step 24-Benzyloxy-2-fluoro-aniline (3)

[0441] To a stirred solution of 4-benzyloxy-2-fluoro-1-nitro-benzene (2) (5.5 g, 22.26 mmol) in ethanol (150 mL) and water (30 mL) was added iron powder (4.98 g, 89.07 mmol) followed by ammonium chloride (9.44 g, 178.2 mmol) and the reaction mixture was stirred at 70 °C for 4 h. After complete consumption of SM, the reaction mass was filtered through celite bed and the mother liquor was evaporated, then the crude reaction mass was diluted with ethyl acetate, washed sequentially with water and brine, dried over sodium sulphate and evaporated under reduced pressure to get the crude product which was purified by column chromatography (100-200 mesh silica gel, eluent: 30% ethyl acetate in hexane) to afford 1.4 g (28.9%) of the title compound as brown liquid. LCMS rt 3.32min MH+218. 1H NMR (400MHz, CDCl3) δ7.38-7.29(m,5H),6.72-6.-6.59(m,3H),5.03(s,2H),3.43(br.s,2H).

[0442] Step 3

[0443] N-[4-(Benzyloxy)-2-fluorophenyl]-2-chloro-5-nitropyrimidin-4-amine (4)

[0444] To a stirred solution of 4-benzyloxy-2-fluoro-aniline (3) (1.4 g, 6.45 mmol) in THF (25 mL) was added 2,4-dichloro-5-nitro-pyrimidine (1.5 g, 7.74 mmol) at 0°C under argon and the reaction mixture was stirred for 4 h at room temperature. After complete consumption of SM, the reaction mass was poured into crushed ice to obtain a precipitate which was collected by filtration to obtain 2.4 g (99.2%) of the title compound as a red solid. LCMS rt 3.65 min MH+375. 1H NMR (400 MHz, CDCl3) δ 10.10 (brs, 1H), 9.16 (s, 1H), 7.93-7.89 (m, 1H), 7.43-7.34 (m, 6H), 6.85-6.-6.82 (m, 2H), 5.07 (s, 2H).

[0445] Step-4

[0446] N-[4-(Benzyloxy)-2-fluorophenyl]-5-nitro-2-[3-(trifluoromethyl)phenyl]pyrimidin-4-amine (5)

[0447] N-[4-(Benzyloxy)-2-fluorophenyl]-2-chloro-5-nitropyrimidine-4-amine (4) (2.4 g, 6.41 mmol) and 3-trifluoromethylphenylboronic acid (1.81 g, 9.62 mmol) were dissolved in dioxane / water (4:1, 40 mL) and treated with CsCO (4.17 g, 12.83 mmol). The solution was degassed for 20-30 min, then PdCl(dppf).DCM catalyst (524 mg, 0.64 mmol) was added and the reaction mixture was heated to 90° C. for 16 h, cooled to room temperature and partitioned between ethyl acetate and water. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (100-200 mesh silica gel, eluted with 20% ethyl acetate in hexane). Fractions containing the desired product were combined and evaporated under reduced pressure to give the title compound as an orange solid (2.5 g, 80.4%) LCMS rt 4.3 min MH + 483

[0448] 1 H NMR(400MHz,DMSO-d6)δ9.98(s,1H),9.4(s,1H),8.64(s,1H),8.52-8.51( m,1H)7.89-7.57(m,3H),7.47-7.37(m,5H),6.9-6.71(m,3H),5.11(s,2H).

[0449] Step 5 4-N-[4-(Benzyloxy)-2-fluorophenyl]-2-[3-(trifluoromethyl)phenyl]pyrimidine-4,5-diamine (6)

[0450] To a stirred solution of 4N-[4-(benzyloxy)-2-fluorophenyl]-5-nitro-2-[3-(trifluoromethyl)phenyl]pyrimidin-4-amine (5) (220 mg, 0.455 mmol) in THF (10 mL) was added Raney nickel (100 mg). The reaction vessel was injected with hydrogen and the reaction mixture was stirred under 1 atm hydrogen pressure for 1 h. After complete consumption of SM (monitored by TLC), the reaction mass was filtered through celite bed and the mother liquor was evaporated to afford 200 mg (96.8%) of crude title compound which was used in the next step without further purification. LCMS rt 3.75 min MH+353.

[0451] Step 6 9-[4-(Benzyloxy)-2-fluorophenyl]-8-(propan-2-yl)-2-[3-(trifluoromethyl)phenyl]-9H-purine

[0452] To a stirred solution of 4-N-[4-(benzyloxy)-2-fluorophenyl]-2-[3-(trifluoromethyl)phenyl]pyrimidine-4,5-diamine (6) (200 mg, 0.441 mmol) in acetic acid (20 mL) was added isobutyraldehyde (44 μL, 0.485 mmol) followed by copper acetate (80 mg, 0.441 mmol) and the reaction mixture was stirred at 100 °C for 2 h under nitrogen. After complete consumption of SM (monitored by TLC), the reaction mixture was diluted with DCM, washed sequentially with sodium bicarbonate and brine, dried over sodium sulfate and evaporated under reduced pressure to give the crude title compound which was used in the next step without further purification. LCMS rt 4.50 min MH+507.

[0453] Step-7

[0454] 3-Fluoro-4-[8-(propan-2-yl)-2-[3-(trifluoromethyl)phenyl]-9H-purin-9-yl]phenol

[0455] To a stirred solution of 9-[4-(benzyloxy)-2-fluorophenyl]-8-(propan-2-yl)-2-[3-(trifluoromethyl)phenyl]-9H-purine (7) (150 mg, 0.29 mmol) in 1,2-dichloroethane (7 mL) was added trifluoroacetic acid (4.5 mL) and the reaction mixture was stirred at 90° C. for 16 h. After complete consumption of the starting material (monitored by TLC and LCMS), the volatiles were evaporated under reduced pressure, the crude compound was diluted with dichloromethane, washed sequentially with sodium bicarbonate solution and brine, the organic layer was dried over sodium sulfate and evaporated under reduced pressure to give the crude product, which was purified by reverse phase preparative HPLC to give 50 mg of the title compound as an off-white solid (40.5%). UPLCrt 3.23min MH+417.1H NMR (400MHz, DMSO-d6) δ10.61(s,1H),9.21(s,1H)8.58-8.54(m,2H),7.85-7.57(m,3H),6.96-6.87(m,2H),3.04-3.01(m,1H),1.31-1.22(m,6H).

[0456] The following compounds were prepared by similar methods:

[0457]

[0458]

[0459]

[0460]

[0461]

[0462]

[0463]

[0464]

[0465]

[0466]

[0467]

[0468]

[0469]

[0470]

[0471]

[0472]

[0473] In vitro testing

[0474] Conventional biological assays using adults or larvae and cytotoxicity assays using MRC-5 cells have been previously described in Mansour, NR et al. (2016). "High Throughput Screening Identifies Novel Lead Compounds with Activity against Larval, Juvenile and Schistosoma mansoni PLoS Negl Trop Dis 10(4):e0004659. Cytotoxicity assays using the HepG2 cell line were performed as described in Molecular Diversity (2015) 19, 251-261.

[0475] (a) Adult Schistosoma mansoni

[0476] (b) Schistosoma mansoni larvae

[0477] (c) Adult Schistosoma haematobium

[0478] (d) Cytotoxicity against human MRC-5 cell line

[0479] (e) Cytotoxicity against human HepG2 cell line

[0480] and PLoS Negl Trop Dis Compared to the compounds disclosed in 10(4):e0004659, the compounds of Examples 1-90 exhibit one or more of the following:

[0481]

[0482]

[0483]

[0484]

[0485] Preferred compounds of the present invention are determined by examining the IC 50 Compounds that kill or significantly damage helminths at lower concentrations within a range of concentrations are preferred. For example, IC 50 Compounds with IC values ​​below 0.5 μM against adults and larvae are more preferred. 50 Compounds with values ​​below 0.1 μM;

[0486] In vivo testing

[0487] Mouse infection and worm recovery

[0488] The method used for subcutaneous infection of mice and subsequent worm recovery was as described in Mansour et al. (2016), except that infection was performed with 150 cercariae and the perfusion medium was citrate water (0.9% sodium chloride, 1.5% trisodium citrate). Perfusion was performed 8 days (adult infection) or 15 days (larval infection) after treatment. The perfusate was collected into a 30 mL universal tube. RBCs (red blood cells) were removed by allowing the perfusate to settle for 10 min, removing most of the supernatant and washing once with 10 mL of perfusion medium as above. A drop of diluted saponin aqueous solution was added to lyse any remaining RBCs, and the worm suspension was poured into a small culture dish marked with a grid. The tube was rinsed into the culture dish and inspected for any remaining worms. Worms were counted using a dissecting microscope. The mouse liver removed after perfusion was squeezed between two thick glass plates, visually inspected, and any remaining worms were added to those counted as above.

[0489] Drug treatment

[0490] To test efficacy against juvenile worms, treatments were performed at day 25 post infection and adult worms were tested at day 42 post infection. Drugs were suspended in 7% Tween-80 / 3% ethanol / double distilled water and drug dispersion was facilitated by vortexing and using an ultrasonic water bath (Formulation F1). Alternatively, drugs were suspended in 10% DMSO, 90% double distilled water containing 50 mM Na2HPO4 and 0.5% Tween-80 by first dissolving or suspending the drug in DMSO and then adding the DMSO solution / suspension to the aqueous solution (Formulation F2). In another set of conditions, drugs were first dissolved in DMSO and then diluted with corn oil to obtain a 5% DMSO + drug solution / suspension (Formulation F3)

[0491] Drug solution / suspension was given at a rate of 10 ml / kg by oral gavage. Positive controls (artemether for larvae and praziquantel for adults) were used in each experiment. Compared to adult Schistosoma mansoni, a single dose of 400 mg / kg oral artemether in mice was equally or more effective against Schistosoma mansoni larvae (Am J Trop Med Hyg. 2010 January; 82(1): 112-4. Activity of artemether and mefloquine against juvenile and adult Schistosoma mansoni in athymic and immunocompetent NMRI mice. Keiser J1, Vargas M, Doenhoff MJ), so it is a useful positive control for drug testing in juvenile stages in mouse screening.

[0492] Results from an in vivo mouse model of infection with adult and larval worms

[0493]

[0494]

[0495] Preferred compounds are those that show at least a 50% statistically significant (P value < 0.05) reduction in worm numbers when orally administered in the mouse infection model described above by examination. For example, compounds 2, 17, 29, 50, 63 and 67.

[0496] More preferred compounds are those that show at least a 50% statistically significant (P value < 0.05) reduction in worm numbers when administered orally at a single dose of 25 mg / kg or less in the mouse infection model described above. For example, compounds 2, 29, 50, and 63.

Claims

1. A compound of formula (1b), (1c) or (1d) or a pharmaceutically acceptable salt thereof, in: R1 is C1-C4 alkyl optionally substituted by up to 5 F atoms, C3-C6 cycloalkyl optionally substituted by 1 methyl group, or C4-C7 cycloalkylmethyl; R2 is H, F, Cl or OMe; R3 is H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH; R4 is H, OH, OMe, OPO(OH)OH or OCH2OPO(OH)OH; The condition is that R3 and R4 cannot both be H; Or R3 and R4, together with the benzene ring to which they are attached, form an indazole group as shown below R5 is H, F, Cl or OMe; R6 is H, F, Cl or OMe; X is N or C-R7, wherein R7 is H or F; R8 is SF5, Br, C1-C3 alkyl optionally substituted by up to 7 F atoms, C3-C4 cycloalkyl, OCH2C≡CH or OC1-C3 alkyl optionally substituted by up to 7 F atoms; R9 is H; and R 10 It is H, F or Me.

2. The compound or pharmaceutically acceptable salt according to claim 1, wherein R1 is methyl, ethyl, n-propyl, isopropyl, cyclopropyl optionally substituted with 1 methyl, cyclobutyl, cyclopropylmethyl, CHF2, CF3 or CH2CF3.

3. The compound or pharmaceutically acceptable salt according to claim 2, wherein R1 is ethyl, isopropyl, cyclopropyl, cyclobutyl, CF3 or CH2CF3.

4. The compound or pharmaceutically acceptable salt according to claim 1, wherein R2 is H, F or Cl.

5. The compound or pharmaceutically acceptable salt according to claim 4, wherein R2 is F or Cl.

6. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 5, wherein R3 is H, OH, OMe or OPO(OH)OH.

7. The compound or pharmaceutically acceptable salt of claim 6, wherein R3 is H.

8. The compound or pharmaceutically acceptable salt according to any one of claims 1-5, wherein R4 is H, OH, OMe or OPO(OH)OH.

9. The compound or pharmaceutically acceptable salt according to claim 8, wherein R4 is OH.

10. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 5, wherein the substituents R3 and R4 are combined with the benzene ring to which they are attached to form an indazole group as shown below Among them, R9 and R 10 Both are H.

11. The compound or pharmaceutically acceptable salt according to any one of claims 1-5, wherein R5 is H or OMe.

12. The compound or pharmaceutically acceptable salt of claim 11, wherein R5 is H.

13. The compound or pharmaceutically acceptable salt of any one of claims 1-5, wherein R6 is H or F.

14. The compound or pharmaceutically acceptable salt of any one of claims 1-5, wherein X is C-R7, wherein R7 is H or F.

15. A compound or pharmaceutically acceptable salt according to any one of claims 1-5, wherein R8 is CF3, CF2CF3, CH2CF3, CH(CH3)2, OCF3, OCH(CH3)2, cyclopropyl, cyclobutyl or SF5.

16. A compound or pharmaceutically acceptable salt according to any one of claims 1 to 5, wherein substituents R2 to R6 are selected to provide the substructure:

17. A compound or pharmaceutically acceptable salt according to any one of claims 1 to 5, wherein substituents R7 and R8 are selected to provide the substructure:

18. The compound or pharmaceutically acceptable salt according to claim 1, wherein the compound is:

19. A compound of formula (1b), (1c) or (1d) as defined in any one of claims 1 to 18, or a pharmaceutically acceptable salt thereof, for use in therapy.

20. A compound of formula (1b), (1c) or (1d) as defined in any one of claims 1 to 18, or a pharmaceutically acceptable salt thereof, for use in the treatment of schistosomiasis.

21. Use of a compound of formula (1b), (1c) or (1d) as defined in any one of claims 1 to 18, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for treating schistosomiasis.

22. A pharmaceutical composition comprising (i) a therapeutically effective amount of a compound of formula (1b), (1c) or (1d) as defined in any one of claims 1 to 18, or a pharmaceutically acceptable salt thereof; and (ii) a pharmaceutically acceptable excipient.

23. Use of the pharmaceutical composition according to claim 22 in the preparation of a medicament for treating schistosomiasis.

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