CD206 Modulators and Their Uses and Preparation Methods

Abstract

The present disclosure relates to compounds of Formula I, Formula II, and Formula III, and pharmaceutically acceptable salts thereof. Variables X, a, b, c, d, R 1‑4 , R 10‑15 and R 17‑22 are disclosed. These compounds can be used for treating cancer disorders, particularly those involving the M2 phenotype of macrophages. Pharmaceutical compositions comprising a compound of Formula I or Formula II or Formula III, and methods of treatment, which include administering compounds of Formula I, Formula II, and Formula III, are also disclosed.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 62 / 950,488, filed on December 19, 2019, which is incorporated herein by reference in its entirety.

[0003] Statement of Government Support

[0004] This invention was made in part with government support from the National Institutes of Health, grant number ZIA - BC011267. The government has certain rights in this invention. Background Art

[0005] 1. Field of the Invention

[0006] The present invention relates to immunotherapeutic agents, and more particularly to compounds that modulate CD206, and their uses and methods of preparation.

[0007] 2. Brief Description of Related Technologies

[0008] Pancreatic cancer is a disease in which malignant (cancerous) cells form in the tissues of the pancreas. Pancreatic cancer often has a poor prognosis, even when diagnosed early. Pancreatic cancer typically spreads rapidly and is rarely detected in its early stages, which is the main reason it is the leading cause of cancer death. In fact, in the United States (U.S.), pancreatic cancer is the fourth leading cause of cancer death in both men and women, with over 44,000 deaths per year. It is projected that by 2030, pancreatic cancer will rank second among all cancer - related deaths in the U.S. Additionally, the 5 - year survival rate for pancreatic cancer in the U.S. is the lowest among solid - organ tumors. There is no reliable screening test for early detection of pancreatic cancer. Signs and symptoms do not appear until pancreatic cancer is very advanced, and complete surgical resection is not possible.

[0009] Standard treatments for pancreatic cancer, including surgery, radiation therapy, and chemotherapy, have largely shown limited efficacy. In fact, approved treatments, including gemcitabine, folfirinox, combinations of gemcitabine and abraxane, and combinations of gemcitabine and erlotinib, can at most improve survival by a few months. Newer therapies have not shown more success, likely due to the thick stroma, a unique immune infiltrate characterized by a lack of cytotoxic tumor - infiltrating T cells, a large number of immunosuppressive pre - tumor myeloid cells, and a relatively lack of abundant blood vessels in the pancreas. Pancreatic ductal adenocarcinoma (PDA) accounts for >90% of pancreatic cancer cases and has a 5 - year survival rate of 6%.

[0010] Recent advances in immunotherapy have changed the way many cancer patients are cared for. However, these positive findings are limited to immunologically "hot" cancers, and in most solid organ cancers such as pancreatic cancer (classified as immunologically "cold"), the hope for immunotherapy through T cell activation has so far been largely inaccessible to patients. These tumors create an immune environment that excludes cytotoxic T cells or induces an exhausted T cell phenotype through a large number of immune evasive cues that frequently involve innate immune cells. In current immuno-oncology therapies, strategies to rejuvenate innate immune cells are rare.

[0011] Tumor cells attract and reprogram innate immune cells, including tumor-associated macrophages (TAMs), to support tumor growth and metastatic spread. While the dichotomous M1 vs. M2 classification neglects to capture the ontogeny and tissue-specific cues of TAMs, generally speaking, M1-like TAMs are considered to be the more common phenotype in the early tumor stage, while M2 TAMs are more prominent in more evolved cancers. CD206 高 M2 TAMs control tumor growth by the excretion of pro-tumor factors or by promoting angiogenesis, the cultivation of cancer stem cells, or the generation of an immune evasive microenvironment.

[0012] CD206 is a member of the large C-type lectin receptor family that targets and modulates M2 macrophages. CD206 participates in the recognition and binding of mannan and fucose carbohydrate residues from microorganisms through its eight carbohydrate recognition domains, or participates in the phagocytosis of collagen fragments generated during tissue injury and wound healing as a scavenger receptor through its fibronectin domain II. Ligand binding or low pH induces "rolling-in" (through multiple Ca+-dependent intramolecular interactions between carbohydrate recognition domains) and the closed ("active") form of the receptor, which in the signaling cascade particularly triggers M2 macrophages, which is achieved through the activation of NF-kB signaling activation of small Rho-GTPases mediated by GRB2 and the induction of phagocytosis and autophagy.

[0013] TAMs express scavenger receptors such as CD206, which promotes tumor angiogenesis, tumor cell migration, maintains the EMT-like phenotype of cancer cells, and metastasis. CD206 高 Expression is associated with poor clinical outcomes in pancreatic cancer and other solid organ cancers. Selective depletion of M2 tumor-associated macrophages may improve anti-tumor immunity and cancer outcomes.

[0014] Using a synthetic host defense peptide design known to modulate innate immune function by binding to the C-type lectin receptor (RP-182), previously shown to bind to the amino acid carbohydrate recognition domain 5 (CRD5) sequence NFGDLVSIQSESEKK of the CD206 receptor: (1) activates phagocytic and autophagic programs in M2 macrophages, leading to metabolic reprogramming of these cells and an M1-like phenotype, and (2) activates intracellular signaling of NF-kB, leading to CD206 activation of caspases 8 and 3 mediated by autocrine TNFα 高 Selective killing of M2 macrophages (U.S. Patent 10,016,480). However, the unfavorable pharmacokinetic (PK) properties of peptide-based innate immune modulators have hindered the clinical prospects of synthetic peptides such as RP-182. Therefore, there is a great need for small molecule modulators of CD206. SUMMARY OF THE INVENTION

[0015] Described herein are small molecule modulators that target the CD206 receptor, methods for their manufacture, compositions containing the compounds, and methods of using the compounds.

[0016] In a first aspect, there is provided a compound of formula I and a pharmaceutically acceptable salt of the compound of formula I.

[0017]

[0018] In formula I, the following conditions are met.

[0019] Each bond shown together by a solid line and a dashed line, can be a single bond, a double bond, or an aromatic bond.

[0020] R 1 is hydrogen, halogen, hydroxy, cyano, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl)cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)heteroaryl, -C(O)C1-C6 alkyl, -C(O)NR 8 R 9 、-(C0-C6 alkyl)NR 5 R 6 、-CO2R 6 、-C6H4-R 7 , and a monocyclic or bicyclic heterocycle of 4 to 10 ring atoms having 1, 2, or 3 ring atoms independently selected from N, S, and O.

[0021] R 2 、R 3 and R 4Each occurrence is independently selected from hydrogen, halogen, hydroxy, cyano, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl) cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -C(O)C1-C6 alkyl, -C(O)NR 5 R 6 、(C0-C6 alkyl)NR 8 R 9 、-CO2R 6 and -C6H4-R 7 。

[0022] a, b, c, d and X are each independently selected from N, C and CH at each occurrence.

[0023] R 5 and R 6 Each occurrence is independently selected from hydrogen, halogen, hydroxy, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 hydroxyalkyl, C1-C6 alkoxy, substituted or unsubstituted -(C0-C6 alkyl) cycloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -C(O)C1-C6 alkyl, -C(O)(C0-C6 alkyl) phenyl, -(C0-C6 alkyl)NR 8 R 9 、-C(O)(C0-C6 alkyl) aryl, -C(O)(C0-C6 alkyl) heteroaryl, and 4- to 7-membered heterocycloalkyl rings having 1, 2 or 3 ring atoms independently selected from N, O and S.

[0024] Any R 5 and R 6 bonded to the same nitrogen atom may together form a 4- to 7-membered monocyclic heterocycloalkyl ring or a 6- to 11-membered bridged bicyclic heterocycloalkyl ring, where the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and where the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: halogen, hydroxy, cyano, oxo, dioxo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl) cycloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl)CO2R 8 、-(C0-C6 alkyl)C(O)NR 8 R 9 、-(C1-C6 alkyl)OR 8 、-C(O)C1-C6 alkyl, -(C0-C6 alkyl)NR8 R 9 or -C(O)(C0-C6 alkyl)NR 8 R 9 。

[0025] R 7 is hydrogen, halogen, hydroxy, cyano, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl)cycloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)heteroaryl, -CO2R 8 、-C(O)C1-C6 alkyl, -C(O)C2-C6 alkenyl, -C(O)C2-C6 alkynyl, -C(O)C1-C6 alkoxy, -C(O)C1-C6 hydroxyalkyl, -C(O)-(C0-C6 alkyl)cycloalkyl, -C(O)-(C0-C6 alkyl)phenyl, -C(O)-(C0-C6 alkyl)aryl, -C(O)-(C0-C6 alkyl)heteroaryl, -C(O)NR 8 R 9 、-C(O)NR 5 R 6 、-C(O)-(C0-C6 alkyl)NR 5 R 6 、-C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 or (C0-C6 alkyl)NR 5 R 6 。

[0026] R 8 and R 9 each independently at each occurrence is selected from hydrogen, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)NR 5 R 6 、-CO2R 6 、-C(O)C1-C6 alkyl and -(C0-C6 alkyl)cycloalkyl.

[0027] In a second aspect, there is provided a compound of formula II and a pharmaceutically acceptable salt of the compound of formula II.

[0028]

[0029] In formula II, the following conditions are satisfied.

[0030] Each bond shown together by a solid line and a dashed line, It can be a single bond or a double bond.

[0031] R 10 、R 11 and R 13 each independently selected from hydrogen, hydroxy, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl) cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -C(O)C1-C6 alkyl, -C(O) heteroaryl and -CO2R 16 .

[0032] R 12 、R 14 and R 15 each independently selected from hydrogen, halogen, hydroxy and cyano at each occurrence.

[0033] X is O or S.

[0034] R 16 is hydrogen, halogen, hydroxy, amino, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl) cycloalkyl, -C(O)C1-C6 alkyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -(C0-C6 alkyl) phenyl, or a monocyclic or bicyclic heterocycle having 4 to 10 ring atoms with 1, 2 or 3 ring atoms independently selected from N, S and O.

[0035] In a third aspect, there is provided a compound of formula III and a pharmaceutically acceptable salt of the compound of formula III.

[0036]

[0037] In formula III, the following conditions are satisfied.

[0038] R 17 、R 18 and R 21 each independently selected from hydrogen, halogen, hydroxy, cyano, amidino, -NR 23 R 24, sulfonic acid group or its salt, phosphoric acid group or its salt, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl) cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -C(O)C1-C6 alkyl, -C(O)(C0-C6 alkyl) phenyl, -C(O)(C0-C6 alkyl) aryl, -C(O)(C0-C6 alkyl) heteroaryl, -C(O)NR 23 R 24 , -(C0-C6 alkyl)NR 23 R 24 , -CO2R 23 , and a monocyclic or bicyclic heterocycle having 4 to 10 ring atoms with 1, 2 or 3 ring atoms independently selected from N, S and O.

[0039] X is independently selected from O and S at each occurrence.

[0040] R 19 , R 20 and R 22 are each independently selected from hydrogen, halogen, hydroxy, cyano and amino at each occurrence.

[0041] R 23 and R 24 are each independently selected from hydrogen, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, C1-C6 haloalkoxy, C1-C6 alkoxy, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -C(O)(C0-C6 alkyl) phenyl, -C(O)(C0-C6 alkyl) aryl, -C(O)(C0-C6 alkyl) heteroaryl, -S(O) phenyl, -S(O) aryl, -S(O) heteroaryl, -SO2 phenyl, -SO2 aryl, -SO2 heteroaryl, -(C0-C6 alkyl) cycloalkyl and -CO2R 25 .

[0042] R 25 is hydrogen, halogen, hydroxy, amino, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl) cycloalkyl, -C(O)C1-C6 alkyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -(C0-C6 alkyl) phenyl, or a monocyclic or bicyclic heterocycle having 4 to 10 ring atoms with 1, 2 or 3 ring atoms independently selected from N, S and O.

[0043] Also disclosed are pharmaceutical compositions comprising a compound or a salt of formula I, formula II, or formula III and a pharmaceutically acceptable carrier.

[0044] Also disclosed is a method for treating cancer, which may involve selectively targeting M2 macrophages in a patient and reprogramming the M2 macrophages into an M1 phenotype, including the step of administering to a patient in need a compound or a salt thereof of formula I, formula II, or formula III.

[0045] In some embodiments, targeting CD206 M2 macrophages with a compound or a salt of formula I, formula II, or formula III may have a dual effect: it can reprogram CD206 M2 macrophages into M1 macrophages and it can directly kill M2 macrophages.

[0046] Also disclosed is a method for treating cancer characterized by the presence of CD206-positive tumor-associated macrophages (TAMs), such as glioma (glioblastoma), sarcoma, astrocytoma, melanoma, non-small cell lung cancer, cholangiocarcinoma, colon cancer, hepatocellular carcinoma, breast cancer, prostate cancer, gastric cancer, renal cell carcinoma, endometrial cancer, or pancreatic cancer, including administering to a patient in need a therapeutically effective amount of a compound or a salt thereof of formula I, formula II, or formula III. Description of the Drawings

[0047] The following detailed description is given by way of examples, but is not intended to limit the invention to the specific embodiments described, which can be understood in conjunction with the accompanying drawings, wherein:

[0048] Figure 1A A graph showing the relationship between the percentage of relative cell viability and the logarithm of the molar concentration, illustrating the anti-cell viability screening of Compound 1;

[0049] Figure 1B A graph showing the relationship between the percentage of relative cell viability and the logarithm of the molar concentration, illustrating the anti-cell viability screening of Compound 2;

[0050] Figure 1C A graph showing the relationship between the percentage of relative cell viability and the logarithm of the molar concentration, illustrating the anti-cell viability screening of Compound 3;

[0051] Figure 2A A graph showing the relationship between the percentage of relative cell viability and the logarithm of the molar concentration, showing the cell viability in M2 polarized macrophages with intact CD206 (wild type) and isogeneic M2 polarized macrophages lacking the CD206 receptor, illustrating that the macrophage activity of Compound 1 is CD206-dependent;

[0052] Figure 2BIt is a graph showing the relationship between the percentage of relative cell viability and the logarithm of molar concentration, which shows the cell viability in M2 polarized macrophages with intact CD206 (wild type) and isogeneic M2 polarized macrophages lacking the CD206 receptor, elucidating that the macrophage activity of Compound 2 is CD206-dependent;

[0053] Figure 2C It shows a graph of the percentage of relative cell viability against the logarithm of molar concentration, showing the cell viability in M2 polarized macrophages with intact CD206 (wild type) and isogeneic M2 polarized macrophages lacking the CD206 receptor, elucidating that the macrophage activity of Compound 3 is CD206-dependent;

[0054] Figure 3A It shows a graph of tumor volume in cubic millimeters (mm 3 ) against the number of days of treatment, elucidating the change in tumor volume during the in vivo test of Compound 1 in fully immunocompetent transgenic Kras (G12D) / Trp53 (R172H) / Pdx-1-Cre (KPC) mice (mouse pancreatic cancer model);

[0055] Figure 3B It shows the change in tumor weight in the vehicle and Compound 1 expressed as wet weight in grams at the study endpoint, elucidating the change in tumor weight during the in vivo test of Compound 1 in fully immunocompetent transgenic Kras (G12D) / Trp53 (R172H) / Pdx-1-Cre (KPC) mice (mouse pancreatic cancer model);

[0056] Figure 3C It shows a graph of tumor volume in cubic millimeters (mm 3 ) against the number of days of treatment, elucidating the change in tumor volume during the in vivo test of Compound 1 in an isogeneic, immunocompetent B16.F10 allograft model (mouse melanoma model);

[0057] Figure 4 It shows a graph of the percentage of relative cell viability against the logarithm of molar concentration, elucidating the macrophage activity of Compound 4 with an IC50 of 8.95 micromoles (μM);

[0058] Figure 5 It shows a graph of the percentage of relative cell viability against the logarithm of molar concentration, elucidating the macrophage activity of Compound 5 with an IC50 of 7.36 μM

[0059] Figure 6 It shows a graph of the percentage of relative cell viability against the logarithm of molar concentration, elucidating the macrophage activity of Compound 6 with an IC50 of 3.85 μM;

[0060] Figure 7 Displays a graph of relative cell viability percentage versus log molar concentration, illustrating the macrophage activity of Compound 7 with an IC50 of 3.13 μM;

[0061] Figure 8 Displays a graph of relative cell viability percentage versus log molar concentration in the cell viability assay of human macrophages for Compound 1, illustrating that Compound 1 is active in human CD206- 高 M2 macrophages isolated from healthy volunteers;

[0062] Figure 9A Displays a graph of relative cell viability percentage versus log molar concentration in a set of CD206-negative control cell lines, illustrating the activity of Compound 1 against CD206 高 M2 macrophages;

[0063] Figure 9B Displays a graph of relative cell viability percentage versus log molar concentration for Compound 1 in a set of dendritic cells DC2.4, illustrating the selectivity of Compound 1 against CD206 高 M2 macrophages;

[0064] Figure 9C Displays a graph of relative cell viability percentage versus log molar concentration for Compound 1 in a set of fibroblasts HTT, illustrating the selectivity of Compound 1 against CD206 高 M2 macrophages;

[0065] Figure 9D Displays a graph of relative cell viability percentage versus log molar concentration for Compound 1 in a set of non-polarized RAW264.7 cells, illustrating the selectivity of Compound 1 against CD206 高 M2 macrophages;

[0066] Figure 9E Displays a graph of relative cell viability percentage versus log molar concentration for Compound 1 in a set of KPC cancer cells (mouse pancreatic cancer cells), illustrating the selectivity of Compound 1 against CD206 高 M2 macrophages;

[0067] Figure 10A Displays a graph of time in hours (hr) versus concentration in nanograms per milliliter (ng / mL) for Compound 1, illustrating the pharmacokinetic (PK) curve of Compound 1 at different concentrations when administered by intravenous (IV) injection;

[0068] Figure 10BShows a graph of time (hr) versus concentration (ng / mL) of Compound 1, illustrating the pharmacokinetic (PK) curves of Compound 1 at different concentrations when administered by intraperitoneal (IP) injection;

[0069] Figure 10C Shows a graph of time (hr) versus concentration (ng / mL) of Compound 1, illustrating the pharmacokinetic (PK) curves of Compound 1 at different concentrations when administered orally;

[0070] Figure 11A Shows representative electron microscopy images of recombinant human CD206 protein (UniProt ID P22897-1 NCBI ID: NP_002429.1) and vehicle relative to Compound 1 incubated for 30 minutes at 1 micromolar (μM), illustrating that Example 38 induced a closed conformation of the CD206 receptor (solid arrow indicates the open conformation of the CD206 receptor; dashed arrow indicates the closed conformation);

[0071] Figure 11B Shows representative serial scanning electron microscopy images of recombinant CD206 and vehicle relative to Compound 1 incubated for 30 minutes at 1 μM, scored as closed and open. The number of CD206 particles in the series was scored as closed and open, as shown at the bottom, which shows that overall, 48% of the CD206 particles were in the closed state (thick border squares) and 52% were in the open state (borderless squares), illustrating that Compound 1 binds to CD206 and induces a conformational switch in the receptor;

[0072] Figure 12A Shows quantitative relative fluorescence graphs obtained in murine M1 and M2 macrophages to indicate induction of early phagocytosis, illustrating that Compound 1 induces early phagocytosis in M2 macrophages but not in M1 macrophages;

[0073] Figure 12B Shows quantitative relative fluorescence graphs obtained in murine M1 and M2 macrophages to indicate induction of phagocytosis, illustrating that Compound 1 induces phagocytosis in M2 macrophages but not in M1 macrophages;

[0074] Figure 12C Shows quantitative relative fluorescence graphs obtained in murine M1 and M2 macrophages to indicate induction of phagolysosome formation, illustrating that Compound 1 induces phagolysosome formation in M2 macrophages but not in M1 macrophages;

[0075] Figure 12DShows the quantitative relative fluorescence graphs obtained in murine M1 macrophages and M2 macrophages to indicate the induction of autophagy, elucidating that compound 1 induces autophagy in M2 macrophages but not in M1 macrophages;

[0076] Figure 12E Shows the quantitative relative fluorescence graphs obtained in murine M1 macrophages and M2 macrophages to indicate the induction of apoptosis, elucidating that compound 1 induces apoptosis in M2 macrophages but not in M1 macrophages;

[0077] Figure 13A Shows the quantitative relative fluorescence graphs obtained in an in vitro macrophage model in a second mouse, where RAW264.7 macrophages are polarized into M1 and M2, to indicate the induction of phagocytosis in RAW264.7 macrophages treated with compound 1 compared to RAW264.7 macrophages treated with only vehicle, elucidating that compound 1 induces phagocytosis in M2 macrophages;

[0078] Figure 13B Shows the quantitative relative fluorescence graphs obtained in an in vitro macrophage model in a second mouse, where RAW264.7 macrophages are polarized into M1 and M2, to indicate the induction of autophagy in RAW264.7 macrophages treated with compound 1 compared to RAW264.7 macrophages treated with only vehicle, elucidating that compound 1 induces autophagy in M2 macrophages;

[0079] Figure 13C Shows the quantitative relative fluorescence graphs obtained in an in vitro macrophage model in a second mouse, where RAW264.7 macrophages are polarized into M1 and M2, to indicate the induction of apoptosis in RAW264.7 macrophages treated with compound 1 compared to RAW264.7 macrophages treated with only vehicle, elucidating that compound 1 induces apoptosis in M2 macrophages;

[0080] Figure 14A Shows the relative quantitative fluorescence graphs to indicate the selective induction of cancer cell phagocytosis in M2 macrophages induced by compound 1, elucidating that compound 1 increases cancer cell phagocytosis in M2 macrophages but not in M1 macrophages;

[0081] Figure 14B Shows the relative quantitative fluorescence graphs to indicate the selective induction of cancer cell phagocytosis in M2 macrophages induced by compound 28, elucidating that compound 28 increases cancer cell phagocytosis in M2 macrophages but not in M1 macrophages;

[0082] Figure 15 Shows the graph of the relationship between the relative cell viability percentage and the logarithmic molar concentration, elucidating the macrophage activity of compound 1 with an IC50 of 2.86 μM;

[0083] Figure 16 Shows a graph of the relative induced immunofluorescence percentage of phagocytosis induction measured in murine M2 macrophages treated with Compound 1 for 24 hours versus log molar concentration, illustrating the concentration-dependent induction of phagocytosis by Compound 1;

[0084] Figure 17 Shows a graph of the percentage of positive cell fraction of M1 markers measured by quantitative flow cytometry in murine M2 macrophages treated with vehicle, 20 μM Compound 1, and 20 μM Compound 2 for 2 hours, illustrating the induction of M1 markers in M2 macrophages;

[0085] Figures 18A to 18C Shows the reprogramming of the intratumoral immune landscape by Compound 1 in primary KPC tumors. Figure 18A Shows a graph of the percentage of positive cell fraction of total cells in tumors measured by quantitative flow cytometry in KPC tumors treated with Compound 1 compared to vehicle (CD206 = M2 macrophages; CD86 = M1 macrophages; CD8a = CD8-positive T cells; CD4 = CD4-positive T cells), illustrating that treatment with Compound 1 showed a decrease in CD206 macrophages, a shift from CD206 高 M2 to CD86-positive M1 macrophages, and an increase in intratumoral CD8 cells. Figure 18B Shows a decrease in CD206-positive cells within the tumor-associated macrophage population measured by CD11b+F4 / 80+Gr-1-negative cells. Figure 18C Shows a decrease in the natural checkpoint signaling regulatory protein α (SIRPα), a regulatory membrane glycoprotein from the SIRP family that inhibits cancer cell phagocytosis by tumor-associated macrophages determined by CD11b+F4 / 80+Gr-1-negative cells;

[0086] Figures 18D to 18I Shows a graph of the percentage of positive cell fraction of intratumoral M1 and M2 macrophage populations measured by quantitative flow cytometry in KPC tumors to indicate changes in the cytokine profile three weeks after treatment with Compound 1 compared to vehicle in KPC mice, illustrating that Compound 1 showed induction of M1 markers in both intratumoral M1 and intratumoral M2 macrophage populations compared to vehicle;

[0087] Figure 19Shows the relative tumor growth of KPC allograft tumors grown in C57BL / 6 mice, indicating that after adoptive transfer of M2 macrophages by intratumoral injection, when the frequency of intratumoral injection is 3 times per week and the measurement frequency is 2 times per week, M2 macrophages limit tumor growth when treated with Compound 1 compared to the vehicle, which is similar to injecting the same number of M1 macrophages, illustrating that treatment with Compound 1 shows that M2 macrophages pretreated with Compound 1 reduce tumor growth, but not when pretreated with the vehicle, indicating that M2 macrophages treated with Compound 1 and injected into the tumor have a tumor-limiting effect;

[0088] Figure 20 Shows a graph of the relative percentage of cell viability versus log molar concentration, illustrating the macrophage activity of Compound 8 with an IC50 of 0.45 μM;

[0089] Figure 21 Shows a graph of the relative percentage of cell viability versus log molar concentration, illustrating the macrophage activity of Compound 9 with an IC50 of 0.73 μM;

[0090] Figure 22 Shows a graph of the relative percentage of cell viability versus log molar concentration, illustrating the macrophage activity of Compound 10 with an IC50 of 5.45 μM. Detailed Description

[0091] Terms

[0092] Compounds are described using standard nomenclature. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0093] The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the items mentioned. The term "or" means "and / or". The terms "comprising", "having", "including", and "containing" are intended to be interpreted as open-ended terms (i.e., meaning "including but not limited to").

[0094] Unless otherwise indicated herein, the recitation of a range of values is merely intended to be a shorthand method of individually referring to each separate value falling within the range, and each separate value is incorporated into the specification as if it were individually described herein. All endpoints of the ranges are included within the range and may be combined independently.

[0095] All of the methods described herein can be performed in any suitable order unless otherwise indicated herein or the context clearly dictates otherwise. The use of any and all examples, or exemplary language (e.g., "such as") is intended to illustrate and does not impose a limitation on the scope of the disclosure unless otherwise required. The language in this specification should not be construed as indicating any non-claimed element as essential for the practice of the invention. Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0096] In addition, the present disclosure includes all such variations, combinations, and permutations in which one or more limitations, elements, clauses, and descriptive terms from one or more of the listed claims are introduced into another claim. For example, any claim that depends from another claim can be modified to include one or more limitations found in any other claim that depends from the same base claim. When elements are presented as a list, e.g., in Markush group format, each subgroup of the elements is also disclosed, and any element can be removed from the group.

[0097] All compounds are understood to include all possible isotopes of the atoms that occur in the compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example, but not limitation, isotopes of hydrogen include tritium and deuterium, and isotopes of carbon include 11 C, 13 C, and 14 C.

[0098] Formula I includes all pharmaceutically acceptable salts of Formula I.

[0099] Formula II includes all pharmaceutically acceptable salts of Formula II.

[0100] Formula III includes all pharmaceutically acceptable salts of Formula III.

[0101] The open-ended term "comprising" includes the intermediate and closed-ended terms "consisting essentially of" and "consisting of".

[0102] The term "substituted" means that any one or more hydrogens on the designated atom or group are replaced with a selected designated group, provided that the normal valence of the designated atom is not exceeded. When the substituent is an oxo group (i.e., =O), then two hydrogens on the atom are replaced. When an aromatic moiety is substituted with an oxo group, the aromatic ring is replaced with the corresponding partially unsaturated ring. For example, pyridyl substituted with an oxo group is pyridone. Combinations of substituents and / or variables are permitted only if such combinations result in a stable compound or a useful synthetic intermediate. Stable compounds and stable structures mean compounds that are sufficiently robust to survive isolation from a reaction mixture and formulation into an effective therapeutic agent.

[0103] Suitable groups that may be present in "optionally substituted" positions include, but are not limited to, for example, halogen, cyano, hydroxy, amino, nitro, oxo, azido, alkanoyl (such as C2-C6 alkanoyl, such as acyl, etc. (-(C=O)alkyl)); formamido; alkylamide; alkyl, alkoxy, alkylthio (including those having one or more thioether bonds), alkylsulfinyl (including those having one or more sulfinyl bonds), alkylsulfonyl (including those having one or more sulfonyl bonds), mono-aminoalkyl and bis-aminoalkyl (including those having one or more N atoms), all of the foregoing optional alkyl substituents may have one or more methylenes replaced by oxygen or -NH- and have from about 1 to about 8, from about 1 to about 6 or 1 to about 4 carbon atoms, cycloalkyl; phenyl; phenylalkyl (wherein benzyl is an exemplary phenylalkyl), phenylalkoxy (wherein benzyloxy is an exemplary phenylalkoxy). Alkylthio and alkoxy are attached to the positions where they are substituted by sulfur or oxygen atoms, respectively.

[0104] A dash ("-") not between two letters or symbols and is used to indicate the point of attachment for substituents.

[0105] "Alkyl" includes branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms (usually from 1 to about 8 carbon atoms). As used herein, the term C1-C6 alkyl indicates an alkyl having 1, 2, 3, 4, 5 or 6 carbon atoms. Other embodiments include alkyls having 1 to 8 carbon atoms, 1 to 4 carbon atoms or 1 or 2 carbon atoms, such as C1-C8 alkyl, C1-C4 alkyl and C1-C2 alkyl. When C0-C n alkyl is used together with another group, such as -C0-C2 alkyl(phenyl), the indicated group, in this case phenyl, is directly attached by a single covalent bond (C0 alkyl), or attached by an alkyl chain having the specified number of carbon atoms (in this case 1, 2, 3 or 4 carbon atoms). Alkyl can also be attached through other groups such as heteroatoms, as in -O-C0-C4 alkyl(C3-C7 cycloalkyl). Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, 3-methylbutyl, tert-butyl, n-pentyl and sec-pentyl.

[0106] "Alkenyl" is a branched or straight-chain aliphatic hydrocarbon group having one or more carbon-carbon double bonds that can occur at any stable point along the chain and having the specified number of carbon atoms. Examples of alkenyl include, but are not limited to, vinyl and propenyl.

[0107] "Alkynyl" is a branched or straight-chain aliphatic hydrocarbon group having one or more carbon-carbon triple bonds that can occur at any stable point along the chain and having the specified number of carbon atoms.

[0108] "Alkoxy" is an alkyl group as defined above, wherein the indicated number of carbon atoms are covalently bonded to a group which is replaced by an oxygen bridge (-O-). Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, 2-butoxy, tert-butoxy, n-pentyloxy, 2-pentyloxy, 3-pentyloxy, isopentyloxy, neopentyloxy, n-hexyloxy, 2-hexyloxy, 3-hexyloxy, and 3-methylpentyloxy. Similarly, "alkylthio" or "thioalkyl" is an alkyl group as defined above, wherein the indicated number of carbon atoms are covalently bonded to a group which is replaced by a sulfur bridge (-S-).

[0109] "Aryl" is a substituted stable monocyclic or polycyclic aromatic ring having from 1 to 60 ring carbon atoms. Aryl includes, but is not limited to, tolyl, xylyl, naphthyl, phenanthryl, and anthracenyl.

[0110] "Cycloalkyl" is a saturated hydrocarbon ring group having a specified number of carbon atoms, typically from 3 to about 7 carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl, as well as bridged or cage-like saturated ring groups such as norbornane or adamantane. "-(C0-C n alkyl)cycloalkyl" is a cycloalkyl group attached to a position which is replaced by a single covalent bond (C0) or an alkylene linking group having from 1 to n carbon atoms.

[0111] "Halo" or "halogen" means fluoro, chloro, bromo, or iodo.

[0112] "Heteroaryl" is a stable monocyclic aromatic ring having an indicated number of ring atoms including from 1 to 3 or in some embodiments 1 to 2 heteroatoms selected from N, O, and S, wherein the remaining ring atoms are carbon; or a stable bicyclic or tricyclic system comprising at least one 5- to 7-membered aromatic ring, said aromatic ring containing from 1 to 3 or in some embodiments 1 to 2 heteroatoms selected from N, O, and S, wherein the remaining ring atoms are carbon. Monocyclic heteroaryl typically has 5 to 7 ring atoms. In some embodiments, bicyclic heteroaryl is 9- to 10-membered heteroaryl, i.e., a group containing 9 or 10 ring atoms, wherein a 5- to 7-membered aromatic ring is fused to a second aromatic or non-aromatic ring. When the total number of S and O atoms in the heteroaryl exceeds 1, these heteroatoms are not adjacent to each other. Preferably, the total number of S and O atoms in the heteroaryl does not exceed 2. Particularly preferably, the total number of S and O atoms in the aromatic heterocycle does not exceed 1. Heteroaryl includes, but is not limited to, oxazolyl, piperazinyl, pyranyl, pyrazinyl, pyrazolopyrimidinyl, pyrazolyl, pyridizinyl, pyridyl, pyrimidinyl, pyrrolyl, quinolinyl, tetrazolyl, thiazolyl, thienylpyrazolyl, thienyl, triazolyl, benzod[d]oxazolyl, benzofuranyl, benzothiazolyl, benzothienyl, benzoxadiazolyl, dihydrobenzodioxynyl, furanyl, imidazolyl, indolyl, isothiazolyl, and isoxazolyl.

[0113] "Heterocycle" is a saturated, unsaturated, or aromatic ring group having an indicated number of ring atoms including from 1 to about 3 heteroatoms selected from N, O, and S, wherein the remaining ring atoms are carbon. Examples of heterocyclic groups include piperazinyl and thiazolyl.

[0114] "Heterocycloalkyl" is a saturated ring group having an indicated number of ring atoms including from 1 to about 3 heteroatoms selected from N, O, and S, wherein the remaining ring atoms are carbon. Examples of heterocycloalkyl include tetrahydrofuranyl and pyrrolidinyl.

[0115] "Haloalkyl" refers to both branched and straight-chain alkyls having a specified number of carbon atoms, which are substituted with one or more halogen atoms, typically up to the maximum allowable number of halogen atoms. Examples of haloalkyl include, but are not limited to, trifluoromethyl, difluoromethyl, 2-fluoroethyl, and pentafluoroethyl.

[0116] "Haloalkoxy" is a haloalkyl attached through an oxygen bridge (the oxygen of the alcohol group) as defined above.

[0117] "Pharmaceutical composition" means a composition comprising at least one active agent such as a compound or salt of formula (I) and at least one other substance such as a carrier. The pharmaceutical composition complies with the GMP (Good Manufacturing Practice) standards of the US FDA for human or non-human drugs.

[0118] "Carrier" means a diluent, excipient or vehicle by which an active compound is administered. "Pharmaceutically acceptable carrier" means a substance that is generally safe, non-toxic and not otherwise undesirable biologically and in other respects, suitable for the preparation of pharmaceutical compositions, such as excipients, diluents or vehicles, and includes carriers acceptable for veterinary as well as human pharmaceutical use. "Pharmaceutically acceptable carrier" includes one and more than one such carrier.

[0119] "Patient" means a human or non-human animal in need of medical treatment. Medical treatment may include treating an existing condition such as a disease or disorder or diagnostic treatment. In some embodiments, the patient is a human patient.

[0120] "Provide" means to give, administer, sell, distribute, transfer (for profit or not), manufacture, compound or dispense.

[0121] "Treatment" or "treating" means providing an active compound to a patient in an amount sufficient to measurably reduce any cancer symptoms, delay cancer progression or cause cancer regression. In certain embodiments, treatment of cancer may be initiated before the patient exhibits symptoms of the disease.

[0122] A "therapeutically effective amount" of a pharmaceutical composition means an effective amount that provides a therapeutic benefit when administered to a patient, such as improving symptoms, reducing cancer progression or causing cancer regression.

[0123] A significant change is any detectable change that is statistically significant in a standard parametric test of statistical significance, such as a Student T test, where p < 0.05.

[0124] Chemical description

[0125] Compounds of formula I or formula II or formula III may contain one or more asymmetric elements, such as stereocenters, stereoaxes, etc., for example, asymmetric carbon atoms, such that the compounds may exist in different stereoisomeric forms. These compounds may be, for example, racemates or optically active forms. For compounds having two or more asymmetric elements, these compounds may additionally be mixtures of diastereomers. For compounds having an asymmetric center, all optical isomers in pure form and their mixtures are included. In these cases, a single enantiomer, i.e., an optically active form, may be obtained by asymmetric synthesis, synthesis from an optically pure precursor or by resolution of a racemate. Resolution of a racemate may also be accomplished, for example, by conventional methods such as crystallization in the presence of a resolving agent or chromatography using, for example, a chiral HPLC column. All forms are contemplated herein, regardless of the method used to obtain them.

[0126] All forms of the active agent, such as solvates, optical isomers, enantiomeric forms, tautomers, polymorphs, free compounds, and salts, can be used alone or in combination.

[0127] The term "chiral" refers to a molecule having non - superposable mirror image partners.

[0128] "Stereoisomers" are compounds having the same chemical composition but different spatial arrangements of atoms or groups.

[0129] "Diastereomers" are stereoisomers having two or more chiral centers and the molecules are not mirror images of each other. Diastereomers have different physical properties such as melting point, boiling point, spectroscopic properties, and reactivity. A mixture of diastereomers can be separated by high - resolution analytical procedures such as electrophoresis, crystallization in the presence of a resolving agent, or chromatography using, for example, a chiral HPLC column.

[0130] "Enantiomers" refer to two stereoisomers of a compound that are non - superposable mirror images of each other. A 50:50 mixture of enantiomers is called a racemic mixture or racemate, which can occur when there is no stereoselectivity or stereospecificity in a chemical reaction or process.

[0131] The stereochemical definitions and conventions used herein generally follow those set forth in S.P. Parker, Editor, McGraw - Hill Dictionary of Chemical Terms (1984) McGraw - Hill Book Company, New York; and Eliel, E. and Wilen, S., Stereochemistry of Organic Compounds (1994) John Wiley & Sons, Inc., New York. Many organic compounds exist in optically active forms, i.e., they are capable of rotating the plane of plane - polarized light. When describing an optically active compound, the prefixes D and L or R and S are used to indicate the absolute configuration of the molecule around its chiral center. The prefixes d and l or (+) and (-) are used to indicate the sign of rotation of plane - polarized light by the compound, where (-) or l means the compound is levorotatory. A compound with the prefix (+) or d is dextrorotatory.

[0132] A "racemic mixture" or "racemate" is an equimolar (or 50:50) mixture of two enantiomeric substances and has no optical activity. A racemic mixture can occur when there is no stereoselectivity or stereospecificity in a chemical reaction or process.

[0133] "Tautomers" or "tautomeric forms" are structural isomers that are readily interconvertible, usually by the migration of a hydrogen atom accompanied by the conversion of a single bond and a double bond.

[0134] "Pharmaceutically acceptable salts" include derivatives of the disclosed compounds, wherein the parent compound is modified by forming its inorganic and organic, non-toxic, acid addition salts or base addition salts. The salts of the compounds of the present invention can be synthesized from the parent compounds containing basic or acidic moieties by conventional chemical methods. Generally, such salts can be prepared by reacting the compounds in their free acid forms with a stoichiometric amount of an appropriate base (such as Na, Ca, Mg or K hydroxides, carbonates, bicarbonates, etc.) or by reacting the compounds in their free base forms with a stoichiometric amount of an appropriate acid. Such reactions are usually carried out in water or in an organic solvent or in a mixture of water and an organic solvent. Generally, when feasible, a non-aqueous medium such as ether, ethyl acetate, ethanol, isopropanol or acetonitrile is used. The salts of the compounds of the present invention also include solvates of the compounds and compound salts.

[0135] Examples of pharmaceutically acceptable salts include, but are not limited to, inorganic acid or organic acid salts of basic residues (such as amines); base salts or organic salts of acidic residues (such as carboxylic acids); etc. Pharmaceutically acceptable salts include, for example, conventional non-toxic salts and quaternary ammonium salts of the parent compounds formed from non-toxic inorganic acids or organic acids. For example, conventional non-toxic acid salts include those salts derived from inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, sulfamic acid, phosphoric acid, nitric acid, etc.; and salts prepared from organic acids such as acetic acid, propionic acid, succinic acid, glycolic acid, stearic acid, lactic acid, malic acid, tartaric acid, citric acid, ascorbic acid, pamoic acid, maleic acid, hydroxymaleic acid, phenylacetic acid, glutamic acid, benzoic acid, salicylic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-aminobenzenesulfonic acid, 2-acetoxybenzoic acid, fumaric acid, toluenesulfonic acid, methanesulfonic acid, ethanedisulfonic acid, oxalic acid, isethionic acid, HOOC-(CH2) n -COOH (where n is 0-4), etc. A list of additional suitable salts can be found, for example, in G. Steffen Paulekuhn et al., Journal of Medicinal Chemistry 2007, 50, 6665 and Handbook of Pharmaceutically Acceptable Salts: Properties, Selection and Use, P. Heinrich Stahl and Camille G. Wermuth Editors, Wiley-VCH, 2002.

[0136] Chemical description

[0137] Molecules that modulate CD206 are disclosed herein.

[0138] In addition to the compounds of Formula I, Formula II, and Formula III shown in the Summary of the Invention section, the present disclosure also includes compounds in which variables such as X and R 1 to R 25 have the following definitions. The present disclosure includes all combinations of these definitions, provided that stable compounds are produced.

[0139] The present disclosure includes the following specific embodiments of Formula I

[0140]

[0141] (A) In one embodiment, R 1 is hydrogen, halogen, hydroxy, cyano, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl)cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)heteroaryl, -C(O)C1-C6 alkyl, -C(O)NR 8 R 9 , -(C0-C6 alkyl)NR 5 R 6 , -CO2R 6 , -C6H4-R 7 , and a monocyclic or bicyclic heterocycle having 4 to 10 ring atoms with 1, 2, or 3 ring atoms independently selected from N, S, and O.

[0142] R 2 and R 4 are H.

[0143] R 3 is hydrogen, halogen, hydroxy, cyano, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl)cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)heteroaryl, -C(O)C1-C6 alkyl, -C(O)NR 5 R 6 , (C0-C6 alkyl)NR 8 R 9 , -CO2R 6 and -C6H4-R 7 .

[0144] a, b, c, and d are each independently selected from N, C, and CH each time they appear.

[0145] X is N.

[0146] R 5 and R6 Each occurrence is independently selected from hydrogen, halogen, hydroxyl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 hydroxyalkyl, C1-C6 alkoxy, substituted or unsubstituted -(C0-C6 alkyl) cycloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -C(O)C1-C6 alkyl, -C(O)(C0-C6 alkyl) phenyl, -(C0-C6 alkyl)NR 8 R 9 , -C(O)(C0-C6 alkyl) aryl, -C(O)(C0-C6 alkyl) heteroaryl, and 4- to 7-membered heterocycloalkyl rings having 1, 2 or 3 ring atoms independently selected from N, O and S.

[0147] Any R bonded to the same nitrogen atom 5 and R 6 may together form a 4- to 7-membered monocyclic heterocycloalkyl ring or a 6- to 11-membered bridged bicyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: halogen, hydroxyl, cyano, oxo, dioxo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl) cycloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl)CO2R 8 , -(C0-C6 alkyl)C(O)NR 8 R 9 , -(C1-C6 alkyl)OR 8 , -C(O)C1-C6 alkyl, -(C0-C6 alkyl)NR 8 R 9 or -C(O)(C0-C6 alkyl)NR 8 R 9 .

[0148] R 7 is hydrogen, halogen, hydroxyl, cyano, -CO2H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl) cycloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl) heteroaryl, -CO2R 8, -C(O)C1-C6 alkyl, -C(O)C2-C6 alkenyl, -C(O)C2-C6 alkynyl, -C(O)C1-C6 alkoxy, -C(O)C1-C6 hydroxyalkyl, -C(O)-(C0-C6 alkyl) cycloalkyl, -C(O)-(C0-C6 alkyl) phenyl, -C(O)-(C0-C6 alkyl) aryl, -C(O)-(C0-C6 alkyl) heteroaryl, -C(O)NR 8 R 9 , -C(O)NR 5 R 6 , -C(O)-(C0-C6 alkyl)NR 5 R 6 , -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 or (C0-C6 alkyl)NR 5 R 6 .

[0149] R 8 and R 9 each independently at each occurrence is selected from hydrogen, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl, -(C0-C6 alkyl)NR 5 R 6 , -CO2R 6 , -C(O)C1-C6 alkyl and -(C0-C6 alkyl) cycloalkyl.

[0150] (B) In one embodiment, R 1 is -C6H4-R 7 .

[0151] R 2 and R 4 are H.

[0152] R 3 is -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl or -(C0-C6 alkyl) heteroaryl.

[0153] a, c and X are N.

[0154] b is C.

[0155] d is CH.

[0156] R 7 is -C(O)NR 5 R 6 or -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R6 .

[0157] R 5 and R 6 each independently selected from hydrogen, substituted or unsubstituted -(C0-C6 alkyl)cycloalkyl, -(C0-C6 alkyl)heteroaryl, C1-C6 hydroxyalkyl, C1-C6 alkoxy, -(C0-C6 alkyl)NR 8 R 9 , and 4- to 7-membered heterocycloalkyl rings having 1, 2 or 3 ring atoms independently selected from N, O and S.

[0158] Any R 5 and R 6 bonded to the same nitrogen atom may together form a 4- to 7-membered monocyclic heterocycloalkyl ring or a 6- to 11-membered bridged bicyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: halogen, hydroxy, cyano, oxo, dioxo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl)cycloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)CO2R 8 , -(C0-C6 alkyl)C(O)NR 8 R 9 , -(C1-C6 alkyl)OR 8 , -CO2R 8 , -C(O)C1-C6 alkyl, -(C0-C6 alkyl)NR 8 R 9 or -C(O)(C0-C6 alkyl)NR 8 R 9 .

[0159] R 8 and R 9 each independently selected from hydrogen, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl, -(C0-C6 alkyl)NR 5 R 6 , -CO2R 6 , -C(O)C1-C6 alkyl and -(C0-C6 alkyl)cycloalkyl.

[0160] (C) In one embodiment, the compound of formula I is a compound represented by at least one of compound 1, compounds 4 to 29:

[0161]

[0162] or a pharmaceutically acceptable salt thereof.

[0163] (D) In one embodiment, R 1 is -C6H4-R 7 .

[0164] R 2 and R 4 are hydrogen.

[0165] R 3 is -(C0-C6alkyl)phenyl, -(C0-C6alkyl)aryl or -(C0-C6alkyl)heteroaryl.

[0166] a, c, d and X are N.

[0167] b is C.

[0168] R 7 is -C(O)-NR 8 -(C0-C6alkyl)NR 5 R 6 .

[0169] R 5 and R 6 bonded to the same nitrogen atom may together form a 4- to 7-membered monocyclic heterocycloalkyl ring or a 6- to 11-membered bridged bicyclic heterocycloalkyl ring, where the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and where the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: halogen, hydroxy, cyano, oxo, dioxo, C1-C6alkyl, C1-C6alkoxy, C1-C6haloalkyl, -(C0-C6alkyl)cycloalkyl, -(C0-C6alkyl)phenyl or -(C0-C6alkyl)aryl.

[0170] R 8 is hydrogen.

[0171] (E) In one embodiment, the compound of formula I is a compound represented by at least one of compound 30 and compound 31:

[0172] or a pharmaceutically acceptable salt thereof.

[0173] (F) In one embodiment, R 1 is -C6H4-R 7 .

[0174] R 2 and R 4 are hydrogen.

[0175] R 3 is -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl or -(C0-C6 alkyl)heteroaryl.

[0176] a is C.

[0177] b, d and X are N.

[0178] c is CH.

[0179] R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 .

[0180] R and R attached to the same nitrogen atom 5 and R 6 may together form a 4- to 7-membered monocyclic heteroalkyl ring or a 6- to 11-membered bridged bicyclic heteroalkyl ring, wherein the heteroalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and wherein the heteroalkyl ring is optionally substituted at any carbon or heteroatom by: halogen, hydroxy, cyano, oxo, dioxo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl)cycloalkyl, -(C0-C6 alkyl)phenyl or -(C0-C6 alkyl)aryl.

[0181] R 8 is hydrogen.

[0182] (G) In one embodiment, the compound of formula I is the compound represented by compound 32:

[0183] or a pharmaceutically acceptable salt thereof.

[0184] (H) In one embodiment, R 1 is -C6H4-R 7 .

[0185] R 2 and R 4 are hydrogen.

[0186] R 3 is -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl or -(C0-C6 alkyl)heteroaryl.

[0187] a is C.

[0188] b and X are N.

[0189] c and d are CH.

[0190] R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 。

[0191] R bonded to the same nitrogen atom 5 and R 6 may together form a 4- to 7-membered monocyclic heteroalkyl ring or a 6- to 11-membered bridged bicyclic heteroalkyl ring, wherein the heteroalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and wherein the heteroalkyl ring is optionally substituted at any carbon or heteroatom by the following groups: halogen, hydroxy, cyano, oxo, dioxo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, -(C0-C6 alkyl) cycloalkyl, -(C0-C6 alkyl) phenyl or -(C0-C6 alkyl) aryl.

[0192] R 8 is hydrogen.

[0193] (I) In one embodiment, the compound of formula I is the compound represented by compound 33:

[0194] or a pharmaceutically acceptable salt thereof.

[0195] This disclosure includes the following specific embodiments of formula II

[0196]

[0197] In some embodiments, the compound of formula II is a compound of formula IIA

[0198]

[0199] (A) In one embodiment, R 10 and R 11 are each independently selected from -(C0-C6 alkyl) phenyl, -(C0-C6 alkyl) aryl and -(C0-C6 alkyl) heteroaryl each time they appear.

[0200] R 12 , R 14 and R 15 are hydrogen.

[0201] R 13 is -C(O) heteroaryl.

[0202] (B) In one embodiment, R 10 is -(C0-C6 alkyl) phenyl.

[0203] R11 is -(C0-C6 alkyl) heteroaryl.

[0204] R 12 and R 14 and R 15 are hydrogen.

[0205] R 13 is -C(O) heteroaryl.

[0206] (C) In one embodiment, the compound of formula IIA is compound 2:

[0207] or a pharmaceutically acceptable salt thereof.

[0208] This disclosure includes the following specific embodiments of formula III

[0209]

[0210] (A) In one embodiment, R 17 is -C(O)C1-C6 alkyl, -C(O)(C0-C6 alkyl)phenyl, -C(O)(C0-C6 alkyl)aryl or -C(O)(C0-C6 alkyl) heteroaryl.

[0211] R 18 is C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, -(C0-C6 alkyl) cycloalkyl, C1-C6 haloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)aryl or -(C0-C6 alkyl) heteroaryl.

[0212] R 19 and R 20 and R 22 are hydrogen.

[0213] R 21 is -NR 23 R 24 .

[0214] X is independently selected from O and S each time it appears.

[0215] R 23 and R 24 are each independently selected from -S(O)phenyl, -S(O)aryl, -S(O)heteroaryl, -SO2phenyl, -SO2aryl, -SO2heteroaryl, -(C0-C6 alkyl) cycloalkyl and -CO2R 25 .

[0216] R 25is a C1-C6 alkyl group, -(C0-C6 alkyl) cycloalkyl group, -(C0-C6 alkyl) aryl group, or -(C0-C6 alkyl) phenyl group.

[0217] (B) In one embodiment, R 17 is -C(O)C1-C6 alkyl.

[0218] R 18 is C1-C6 alkyl.

[0219] R 19 、R 20 and R 22 are hydrogen.

[0220] R 21 is -NR 23 R 24 .

[0221] X is oxygen.

[0222] R 23 and R 24 are each independently selected, upon each occurrence, from substituted or unsubstituted arylsulfonyl, -CO2R 25 , -SO2 phenyl, -SO2 aryl, and -SO2R 25 .

[0223] R 25 is phenyl.

[0224] In one embodiment, the compound of formula III is compound 3: or a pharmaceutically acceptable salt thereof.

[0225] Treatment methods

[0226] The compounds of formula I, formula II, or formula III, or salts thereof, and pharmaceutical compositions containing said compounds can be used to treat cancer, including achieving tumor regression in vivo. Methods of treating cancer or achieving tumor regression include providing a patient with an effective amount of a compound of formula I, formula II, or formula III. In one embodiment, the patient is a mammal, and more specifically a human. The present disclosure also provides methods of treating non-human patients, such as companion animals, e.g., cats, dogs, and livestock animals. The effective amount of the pharmaceutical composition can be an amount sufficient to inhibit the progression of cancer or a cancerous tumor; or an amount that causes regression of cancer or a cancerous tumor.

[0227] When administered to a patient, the effective amount of the compounds or pharmaceutical compositions described herein will also provide a sufficient concentration of the compound of formula I, formula II, or formula III. A sufficient concentration is the concentration of the compound necessary in the patient's body to combat the condition. Such an amount can be determined experimentally, e.g., by analyzing the blood concentration of the compound, or theoretically by calculating bioavailability.

[0228] The treatment method includes providing a patient with a certain dose of a compound of Formula I, Formula II or Formula III. A dose level of about 20 milligrams (mg) or less per kilogram of body weight per day for each compound is suitable for treating the diseases indicated above. The dosing frequency may also vary depending on the compound used and the specific disease being treated.

[0229] The compounds of Formula I, Formula II or Formula III can be used to treat cancer and achieve regression of tumors, including cancerous tumors. In certain embodiments, the patient has a cell proliferative disorder or disease. The cell proliferative disorder can be cancer, a tumor (cancerous or benign), a neoplasm, neovascularization or melanoma. Cancers for treatment include solid cancers and disseminated cancers. Exemplary solid cancers (tumors) that can be treated by the methods provided herein include, for example, lung cancer, prostate cancer, breast cancer, liver cancer, colon cancer, breast cancer, kidney cancer, pancreatic cancer, brain cancer, skin cancer (including malignant melanoma and Kaposi's sarcoma), testicular cancer or ovarian cancer, malignant carcinoma, kidney cancer (renal cell) and sarcoma.

[0230] Cancers that can be treated using the compounds of Formula I, Formula II or Formula III also include bladder cancer, breast cancer, colon cancer, endometrial cancer, lung cancer, bronchial cancer, melanoma, non-Hodgkin lymphoma, blood cancer, pancreatic cancer, prostate cancer, thyroid cancer, brain or spinal cord cancer, and leukemia. Exemplary disseminated cancers include leukemia or lymphoma, including Hodgkin's disease, multiple myeloma and mantle cell lymphoma (MCL), chronic lymphocytic leukemia (CLL), T-cell leukemia, multiple myeloma, and Burkitt's lymphoma. Specifically, provided herein is a method for treating cancer by providing a patient with a compound of Formula I, Formula II or Formula III, wherein the cancer is a solid tumor or a disseminated cancer.

[0231] In addition, provided is a method for treating cancer by providing a patient with a compound of Formula I, Formula II or Formula III, wherein the cancer is selected from glioma (glioblastoma), acute myeloid leukemia, acute myelogenous leukemia, myelodysplastic / myeloproliferative neoplasms, sarcoma, chronic myelomonocytic leukemia, non-Hodgkin lymphoma, astrocytoma, melanoma, non-small cell lung cancer, cholangiocarcinoma, chondrosarcoma or colon cancer.

[0232] However, it should be understood that the specific dose level for any particular patient will depend on a variety of factors, including the activity of the specific compound used, age, body weight, general health, gender, diet, time of administration, route of administration and rate of excretion, drug combination, and the severity of the specific disease undergoing therapy.

[0233] Compounds of Formula I, Formula II, or Formula III may be administered alone (i.e., the sole therapeutic agent of the regimen) to treat diseases and disorders such as unwanted cell proliferation, cancer, and / or tumor growth, or may be administered in combination with another active agent. One or more compounds of Formula I, Formula II, or Formula III may be co-administered synergistically with a regimen of one or more other chemotherapeutic agents, such as antineoplastic agents, e.g., alkylating agents (e.g., mechlorethamine, chlorambucil, cyclophosphamide, melphalan, or ifosfamide), antimetabolites such as folic acid antagonists (e.g., methotrexate), purine antagonists (e.g., 6-mercaptopurine), or pyrimidine antagonists (e.g., 5-fluorouracil). Other non-limiting examples of chemotherapeutic agents that may be used synergistically with one or more compounds of Formula I, Formula II, or Formula III include taxanes and topoisomerase inhibitors. In addition, other non-limiting examples of active therapeutic agents include biological agents that obtain their therapeutic effect by specifically binding to receptors or ligands in cancer-related signal transduction pathways, such as monoclonal antibodies or IgG chimeric molecules (e.g., therapeutic antibodies against CD20 (e.g., rituximab) or therapeutic antibodies against VEGF (e.g., bevacizumab)).

[0234] The treatment methods provided herein may also be used to treat mammals other than humans, including for veterinary applications, such as treating horses and livestock, e.g., cattle, sheep, cows, goats, pigs, etc., and pets (companion animals) such as dogs and cats.

[0235] For diagnostic or research applications, a variety of mammals would be suitable subjects, including rodents (e.g., mice, rats, hamsters), rabbits, primates, and pigs such as inbred pigs, etc. In addition, for in vitro applications, such as in vitro diagnostic and research applications, body fluids (e.g., blood, plasma, serum, interstitial fluid, saliva, feces, and urine) and cell and tissue samples from the above subjects would be suitable for use.

[0236] In one embodiment, the present invention provides a method for treating cancer in a patient identified as in need of such treatment, the method comprising providing the patient with an effective amount of a compound of Formula I, Formula II, or Formula III. The compounds and salts of Formula I, Formula II, or Formula III provided herein may be administered alone or in combination with one or more other active agents.

[0237] In one embodiment, the cancer to be treated is characterized by selectively targeting M2 macrophages in the patient and reprogramming the M2 macrophages to an M1 phenotype.

[0238] As Figure 19In the study of adoptive transfer of M2 macrophages in a KPC allograft model in C57BL / 6 mouse models, compared with the vehicle, compound 1 showed tumor reduction with M2 macrophages, where the frequency of intratumoral injection was 3 times a week and the measurement frequency was 2 times a week.

[0239] As Figure 3B shown, tumor growth was inhibited during in vivo testing of compound 1 in fully immunocompetent transgenic Kras(G12D) / Trp53(R172H) / Pdx-1-Cre (KPC) mice (mouse pancreatic cancer model) compared with the vehicle. This is further illustrated in Figure 3A and 3C which shows a comparison of tumor volumes of mice treated with compound-1 and untreated mice (vehicle).

[0240] As Figures 18A to 18C shown, flow cytometry analysis of KPC tumors treated with compound 1 compared with the vehicle showed that treatment with compound 1 showed a decrease in CD206 macrophages, a shift from CD206 高 M2 to CD86-positive M1 macrophages, and an increase in intratumoral CD8 cells;

[0241] As Figures 18D to 18I shown, when the cytokine and immune checkpoint profiles were compared with the vehicle after two weeks of treatment with compound 1 in KPC mice, it showed that compound 1 selectively infiltrated tumors with M2 macrophages compared with M1 macrophages.

[0242] Examples

[0243] Abbreviations

[0244] ACN Acetonitrile

[0245] AcOH Acetic acid

[0246] DCM Dichloromethane

[0247] DCE 1,2-Dichloroethane

[0248] DIPEA Diisopropylethylamine

[0249] DMF Dimethylformamide

[0250] DMSO Dimethyl sulfoxide

[0251] EDC Dichloroethane

[0252] EtOAc Ethyl acetate

[0253] EtOH Ethanol

[0254] ESI Electrospray ionization

[0255] HATU 1H-Azabenzotriazole tetra-methyl uronium hexafluorophosphate

[0256] HEX / Hex Hexane

[0257] HOBt 1-Hydroxybenzotriazole

[0258] HPLC High Performance Liquid Chromatography

[0259] LCMS Liquid Chromatography / Mass Spectrometry

[0260] MHz Megahertz

[0261] μL Microliter

[0262] mL Milliliter

[0263] mg Milligram

[0264] mmol Millimole

[0265] NMR Nuclear Magnetic Resonance

[0266] TLC Thin Layer Chromatography

[0267] General Method

[0268] All air- or moisture-sensitive reactions were carried out in oven-dried glassware under a positive pressure of nitrogen. Anhydrous solvents such as dichloromethane, N,N-dimethylformamide (DMF), acetonitrile (ACN), methanol (MeOH), and triethylamine (Et3N) were purchased from Sigma-Aldrich (St. Louis, MO). Preparative purification was performed on a Waters semi-preparative HPLC system (Waters Corp., Milford, MA). The column used was a Phenomenex Luna C18 (5 µm, 30 x 75 mm; Phenomenex, Inc., Torrance, CA) with a flow rate of 45.0 mL / min. The mobile phase consisted of acetonitrile and water (each containing 0.1% trifluoroacetic acid). A gradient of 10% to 50% acetonitrile over 8 minutes was used during purification. Fraction collection was triggered by UV detection at 220 nm. Analytical analysis was performed on an Agilent LCMS (Agilent Technologies, Santa Clara, CA). Method 1: A 7-minute gradient of 4% to 100% acetonitrile (containing 0.025% trifluoroacetic acid) in water (containing 0.05% trifluoroacetic acid) with a run time of 8 minutes and a flow rate of 1.0 mL / min was used. Method 2: A 3-minute gradient of 4% to 100% acetonitrile (containing 0.025% trifluoroacetic acid) in water (containing 0.05% trifluoroacetic acid) with a run time of 4.5 minutes and a flow rate of 1.0 mL / min was used. A Phenomenex Luna C18 column (3 µm, 3 x 75 mm) was used at a temperature of 50 °C. Purity determination for both Method 1 and Method 2 was performed using an Agilent diode array detector. Mass determination was performed using an Agilent 6130 mass spectrometer with electrospray ionization in the positive ion mode. 1 1H NMR spectra were recorded on a Varian 400 MHz spectrometer (Agilent Technologies, Santa Clara, CA). Chemical shifts were reported in ppm with the undeuterated solvents (2.50 ppm for DMSO and 7.26 ppm for CHCl3) as internal standards for DMSO-d6 and CDCl3 solutions, respectively. Based on two analytical methods, the purity of all analogs tested in the biological assay was greater than 95%. High-resolution mass spectra were recorded on an Agilent 6210 time-of-flight (TOF) LCMS system. The Agilent Masshunter software (version B.02) was used with electrospray ionization in the positive ion mode to confirm the molecular formula. Starting materials were purchased from Combi-Blocks (San Diego, CA) or Sigma-Aldrich (St. Louis, MO) and used without further purification.

[0269] Example 1

[0270] Synthesis of 2-(azidomethyl)-5-chloropyrazine

[0271]

[0272] Thionyl chloride (505 μL, 6.92 mmol) was added to a solution of (5-chloropyrazin-2-yl)methanol (500 mg, 3.46 mmol) and catalytic DMF in DCM (20.0 mL). The resulting reaction mixture was stirred at room temperature for 1 hour (h), after which LCMS and TLC (20% EtOAc / HEX) analysis showed completion. The reaction mixture was concentrated to dryness, taken up in DCM and concentrated to dryness again. The residue was taken up in DMF (10.0 mL) and potassium carbonate (478 mg, 3.46 mmol) was added, followed by sodium azide (270 mg, 4.15 mmol). The resulting reaction mixture was stirred at room temperature for 2 hours, after which LC-MS analysis showed completion. The reaction mixture was taken up in H2O, extracted twice with EtOAc, the combined organic layers were washed twice with brine, dried over anhydrous MgSO4, filtered and concentrated to give 2-(azidomethyl)-5-chloropyrazine (587 mg, 3.46 mmol, 100% yield) as a golden oil, which was used without further purification. 1 1H NMR (400 MHz, DMSO-d6) δ 8.84 (d, J = 1.4 Hz, 1H), 8.57 (d, J = 1.2 Hz, 1H), 4.64 (s, 2H). LCMS retention time (RT) (method 2) = 2.644 min, m / z 170.6 [M+H + .

[0273] Example 2

[0274] Synthesis of (5-chloropyrazin-2-yl)methanamine, HCl

[0275]

[0276] To a solution of 2-(azidomethyl)-5-chloropyrazine (587 mg, 3.46 mmol) in MeOH (40.0 mL) was added triphenylphosphine (1.36 g, 5.19 mmol). The resulting reaction mixture was equipped with a condenser and stirred at 80 °C for 1.5 h, after which LCMS and TLC (20% EtOAc / Hex) analysis showed completion. The reaction mixture was concentrated to dryness and the residue was taken up in toluene (25.0 mL) and treated with 4.0 M HCl in dioxane (2.00 mL, 8.00 mmol), and the product precipitated out as the hydrochloride salt. The solid was filtered, rinsed with toluene and air-dried to give crude (5-chloropyrazin-2-yl)methanamine, HCl (550 mg, 3.05 mmol, 88% yield) as a tan solid, which was used without further purification. 1 H NMR (400 MHz, DMSO-d6) δ 8.88 (d, J = 1.4 Hz, 1H), 8.68 (d, J = 1.4 Hz, 1H), 8.65 (s, 3H), 4.26 (s, 2H).

[0277] Example 3

[0278] Synthesis of methyl 4-(((5-chloropyrazin-2-yl)methyl)carbamoyl)benzoate

[0279]

[0280] A mixture of 4-(methoxycarbonyl)benzoic acid (605 mg, 3.36 mmol) and HATU (1394 mg, 3.67 mmol) in DMF (10.0 mL) was stirred for 10 min. (5-Chloropyrazin-2-yl)methanamine, HCl (550 mg, 3.05 mmol) was added and the mixture was stirred for 5 min, then DIPEA (1.87 mL, 10.7 mmol) was added and the resulting reaction mixture was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with H2O and extracted twice with EtOAc. The combined organic layers were washed twice with brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 20 - 60% EtOAc / Hex to give methyl 4-(((5-chloropyrazin-2-yl)methyl)carbamoyl)benzoate (897 mg, 2.93 mmol, 96% yield) as an off-white solid. 11H NMR (400 MHz, DMSO-d6) δ 9.37 (t, J = 5.7 Hz, 1H), 8.75 (d, J = 1.4 Hz, 1H), 8.53 (d, J = 1.4 Hz, 1H), 8.07–8.04 (m, 2H), 8.03–7.99 (m, 2H), 4.63 (d, J = 5.7 Hz, 2H), 3.88 (s, 3H). LCMS RT (Method 2) = 2.886 min, m / z 635.6 [2M+Na + .

[0281] Example 4

[0282] Synthesis of methyl 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)benzoate

[0283]

[0284] A solution of 1 molar (M) of trifluoromethanesulfonic anhydride (3.52 mL, 3.52 mmol) in DCM was slowly added to a solution of methyl 4-(((5-chloropyrazin-2-yl)methyl)carbamoyl)benzoate (897 mg, 2.93 mmol) and 2-methoxypyridine (339 μL, 3.23 mmol) in DCE (10.0 mL). The resulting reaction mixture was then placed in a preheated reaction block at 45 °C and stirred for 2 h, after which LCMS analysis showed completion. The reaction mixture was cooled to room temperature and quenched by the addition of saturated sodium carbonate solution, stirred for 5 min, diluted with DCM and H2O, the layers were separated and the organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was triturated in EtOH containing 10% hexanes, filtered, rinsed with hexanes and air-dried to give methyl 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)benzoate (671 mg, 2.33 mmol, 79% yield) as a light brown solid, which was used without further purification. 1 1H NMR (400 MHz, DMSO-d6) δ 9.10 (d, J = 1.4 Hz, 1H), 8.66 (t, J = 1.2 Hz, 1H), 8.17 (d, J = 1.0 Hz, 1H), 8.14 (d, J = 8.8 Hz, 2H), 8.11 (d, J = 8.9 Hz, 2H), 3.91 (s, 3H). LCMS RT (Method 2) = 3.071 min, m / z 287.8 [M + .

[0285] Example 5

[0286] Synthesis of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid

[0287]

[0288] A mixture of methyl 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)benzoate (100 mg, 0.348 mmol), (3-fluorophenyl)boronic acid (58.4 mg, 0.417 mmol), XPhosPd(crotyl)Cl (11.71 mg, 0.017 mmol) and K3PO4 (148 mg, 0.695 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 Dioxane-H2O (2.50 mL) was added and degassing continued for 2 minutes, then the reaction vessel was placed in a preheated block at 90 °C. After stirring at 90 °C for 30 minutes, LCMS analysis showed completion. The reaction mixture was cooled to room temperature, diluted with EtOAc and H2O, filtered through celite and the layers were separated. The organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was triturated in EtOH containing 10% hexanes, filtered, rinsed with hexanes and air dried to give the intermediate methyl ester compound, which was taken up in 1:1 EtOH-THF (5.00 mL) and treated with 2 M sodium hydroxide (2.00 mL, 4.00 mmol). The resulting reaction mixture was stirred at room temperature for 2 hours, after which LCMS analysis showed completion. The reaction mixture was concentrated to a slurry, the residue was taken up in H2O and the pH was adjusted to ~5 with AcOH and the product precipitated. The product was then collected by filtration, washed well with H2O and air dried to afford 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (96.0 mg, 0.289 mmol, 83% yield) as an off-white solid, which was used without further purification. 1 1H NMR (400 MHz, DMSO-d6) δ 13.15 (s, 1H), 9.30 (d, J = 1.6 Hz, 1H), 8.89–8.84 (m, 1H), 8.15 (s, 4H), 8.10 (d, J = 0.9 Hz, 1H), 7.98–7.90 (m, 2H), 7.53 (td, J = 8.2, 6.3 Hz, 1H), 7.30–7.20 (m, 1H). 19 19F NMR (376 MHz, DMSO-d6) δ -112.98 (td, J = 9.9, 6.3 Hz). LCMS RT (method 2) = 3.144 min, m / z 334.8 [M+H + 。

[0289] Example 6

[0290] Synthesis of 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)-N-(3-(2-oxopyrrolidin-1-yl)propyl)benzamide

[0291]

[0292] A solution of LiOH (125 mg, 5.21 mmol) in H2O (1.00 mL) was added to a solution of methyl 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)benzoate (300 mg, 1.043 mmol) in THF (4.00 mL). The resulting reaction mixture was stirred at room temperature for 1 h, after which LCMS analysis showed completion. The reaction mixture was concentrated to a slurry, the residue was taken up in H2O and the pH was adjusted to ~5 with AcOH, and the product precipitated. The product was then collected by filtration, washed thoroughly with H2O and air dried to afford the intermediate acid, which was used without further purification.

[0293] A mixture of the intermediate 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)benzoic acid (203 mg, 0.742 mmol) and HATU (310 mg, 0.816 mmol) in DMF (5.00 mL) was stirred for 10 min, then 1-(3-aminopropyl)pyrrolidin-2-one (105 mg, 0.742 mmol) was added. The resulting reaction mixture was stirred for 20 min, then DIPEA (259 μL, 1.48 mmol) was added and the reaction was stirred for 2 h, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0–30% MeOH / EtOAc to give 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)-N-(3-(2-oxopyrrolidin-1-yl)propyl)benzamide (207 mg, 0.520 mmol, 70.1% yield) as an off-white solid. 1 1H NMR (400 MHz, chloroform-d) δ 8.87 (d, J = 1.4 Hz, 1H), 8.21 (t, J = 1.2 Hz, 1H), 8.17 (d, J = 8.4 Hz, 2H), 8.08 (s, 1H), 8.01 (d, J = 1.0 Hz, 1H), 7.91 (d, J = 8.4 Hz, 2H), 3.49–3.44 (m, 6H), 2.50 (t, J = 8.1 Hz, 2H), 2.17–2.07 (m, 2H), 1.86–1.77 (m, 2H). LCMS RT (method 2) = 2.772 min, m / z 398.8 [M+H + .

[0294] Example 7

[0295] Synthesis of N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-(pyridin-3-yl)imidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 26)

[0296]

[0297] A mixture of 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)-N-(3-(2-oxopyrrolidin-1-yl)propyl)benzamide (10.0 mg, 0.025 mmol), pyridin-3-ylboronic acid (3.71 mg, 0.030 mmol), XPhosPd(crotyl)Cl (0.847 mg, 1.26 μmol), and K3PO4 (10.7 mg, 0.050 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 Dioxane-H2O (2.50 mL) was added and degassing continued for 2 minutes, then the reaction vessel was placed in a preheated block at 90 °C. After stirring at 90 °C for 30 minutes, LCMS analysis showed completion. The reaction mixture was cooled to room temperature and loaded directly onto a silica column and purified by flash column chromatography: silica, gradient 5-50% MeOH / EtOAc to give N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-(pyridin-3-yl)imidazo[1,5-a]pyrazin-3-yl)benzamide (9.3 mg, 0.021 mmol, 84% yield) as an off-white crystalline solid. 1 1H NMR (400 MHz, chloroform-d) δ 9.14 (d, J = 1.6 Hz, 1H), 9.13 (dd, J = 2.4, 0.9 Hz, 1H), 8.66 (dd, J = 4.8, 1.6 Hz, 1H), 8.50 (dd, J = 1.6, 1.0 Hz, 1H), 8.23 (ddd, J = 8.0, 2.4, 1.7 Hz, 1H), 8.20–8.16 (m, 2H), 8.08 (t, J = 6.3 Hz, 1H), 8.00 (d, J = 0.9 Hz, 1H), 7.98–7.93 (m, 2H), 7.42 (ddd, J = 8.0, 4.8, 0.9 Hz, 1H), 3.46 (tt, J = 7.4, 2.7 Hz, 6H), 2.49 (dd, J = 8.7, 7.6 Hz, 2H), 2.17–2.06 (m, 2H), 1.87–1.77 (m, 2H). LCMS RT (Method 1) = 3.232 min, m / z 441.9 [M+H + .

[0298] Example 8

[0299] Synthesis of N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-(3-(trifluoromethyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 27)

[0300]

[0301] A mixture of 4-(6-chloroimidazo[1,5-a]pyrazin-3-yl)-N-(3-(2-oxopyrrolidin-1-yl)propyl)benzamide (10.0 mg, 0.025 mmol), (3-(trifluoromethyl)phenyl)boronic acid (5.73 mg, 0.030 mmol), XPhosPd(crotyl)Cl (0.847 mg, 1.26 μmol), and K3PO4 (10.7 mg, 0.050 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 Dioxane-H2O (2.50 mL) was added and degassing was continued for 2 minutes, then the reaction vessel was placed in a preheated block at 90 °C. After stirring at 90 °C for 30 minutes, LCMS analysis showed completion. The reaction mixture was cooled to room temperature and loaded directly onto a silica gel column and purified by flash column chromatography: silica gel, gradient 0-30% MeOH / EtOAc to give N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-(3-(trifluoromethyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)benzamide (10.2 mg, 0.020 mmol, 80% yield) as an off-white crystalline solid. 1 1H NMR (400 MHz, chloroform-d) δ 9.14 (d, J = 1.6 Hz, 1H), 8.50 (dd, J = 1.7, 1.0 Hz, 1H), 8.23 (dd, J = 2.0, 1.1 Hz, 1H), 8.21–8.17 (m, 2H), 8.10–8.02 (m, 2H), 7.99 (d, J = 0.9 Hz, 1H), 7.98–7.94 (m, 2H), 7.70–7.65 (m, 1H), 7.59 (dt, J = 7.8, 0.7 Hz, 1H), 3.46 (tt, J = 7.5, 2.7 Hz, 6H), 2.53–2.44 (m, 2H), 2.17–2.06 (m, 2H), 1.83 (qd, J = 7.7, 6.9, 5.1 Hz, 2H). 19 19F NMR (376 MHz, CDCl3) δ -62.60 (s, 3F). LCMS RT (Method 1) = 5.058 min, m / z 508.8 [M+H + .

[0302] Example 9

[0303] Synthesis of N-(2-morpholinoethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 4)

[0304]

[0305] A mixture of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (50.0 mg, 0.159 mmol) and HATU (72.3 mg, 0.190 mmol) in DMF (2.00 mL) was stirred for 10 minutes, then 2-morpholinoethan-1-amine (22.7 mg, 0.174 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (69.2 μL, 0.396 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was triturated in EtOH, filtered and air-dried to give N-(2-morpholinoethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (49.3 mg, 0.115 mmol, 72.7% yield) as a pale gold solid. 1 1H NMR (400 MHz, chloroform-d) δ 9.14 (d, J = 1.6 Hz, 1H), 8.47 (dd, J = 1.6, 1.0 Hz, 1H), 8.03–7.92 (m, 5H), 7.92–7.85 (m, 2H), 7.52–7.46 (m, 2H), 7.45–7.40 (m, 1H), 6.87 (s, 1H), 3.79–3.72 (m, 4H), 3.66–3.57 (m, 2H), 2.65 (t, J = 6.0 Hz, 2H), 2.54 (t, J = 4.6 Hz, 4H). LCMS RT (Method 1) = 3.645 min, m / z 428.1 [M+H + .

[0306] Figure 4 The IC50 of Compound 4 was shown to be 8.95 μM.

[0307] Example 10

[0308] Synthesis of N-(2-acetamidoethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 14)

[0309]

[0310] A mixture of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (50.0 mg, 0.159 mmol) and HATU (72.3 mg, 0.190 mmol) in DMF (2.00 mL) was stirred for 10 minutes, then N-(2-aminoethyl)acetamide (17.8 mg, 0.174 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (69.2 μL, 0.396 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0 - 20% MeOH / EtOAc to give N-(2-acetamidoethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (41.3 mg, 0.103 mmol, 65.2% yield) as an off-white solid. 1 1H NMR (400 MHz, DMSO-d6) δ 9.29 (d, J = 1.5 Hz, 1H), 8.74 (dd, J = 1.6, 1.0 Hz, 1H), 8.67 (t, J = 5.6 Hz, 1H), 8.15–8.03 (m, 7H), 8.00 (t, J = 5.9 Hz, 1H), 7.54–7.46 (m, 2H), 7.46–7.38 (m, 1H), 3.40–3.28 (m, 2H), 3.28–3.19 (m, 2H), 1.83 (s, 3H). LCMS RT (Method 1) = 3.515 min, m / z 400.1 [M+H + .

[0311] Example 11

[0312] Synthesis of (1,1-dioxosulfolane)(4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)phenyl)methanone (Compound 15)

[0313]

[0314] A mixture of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (50.0 mg, 0.159 mmol) and HATU (72.3 mg, 0.190 mmol) in DMF (2.00 mL) was stirred for 10 minutes, then thiomorpholine 1,1-dioxide (21.4 mg, 0.159 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (69.2 μL, 0.396 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was triturated in EtOH, filtered and air-dried to give (1,1-dioxothiomorpholino)(4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)phenyl)methanone (54.6 mg, 0.126 mmol, 80% yield) as a pale gold solid. 1 1H NMR (400 MHz, chloroform-d) δ 9.15 (d, J = 1.6 Hz, 1H), 8.44 (dd, J = 1.6, 1.0 Hz, 1H), 8.01–7.96 (m, 3H), 7.92–7.86 (m, 2H), 7.69–7.64 (m, 2H), 7.53–7.47 (m, 2H), 7.46–7.41 (m, 1H), 4.16 (s, 4H), 3.11 (s, 4H). LCMS RT (method 1) = 3.845 min, m / z 433.1 [M+H + .

[0315] Example 12

[0316] Synthesis of N-(3-hydroxypropyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 16)

[0317]

[0318] A mixture of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (50.0 mg, 0.159 mmol) and HATU (72.3 mg, 0.190 mmol) in DMF (2.00 mL) was stirred for 10 minutes, then 3-aminopropan-1-ol (13.1 mg, 0.174 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (69.2 μL, 0.396 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0-20% MeOH / EtOAc to give N-(3-hydroxypropyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (41.3 mg, 0.111 mmol, 69.9% yield) as an off-white foam. 1 1H NMR (400 MHz, DMSO-d6) δ 9.29 (d, J = 1.5 Hz, 1H), 8.74 (dd, J = 1.6, 1.0 Hz, 1H), 8.60 (t, J = 5.6 Hz, 1H), 8.15–8.00 (m, 7H), 7.54–7.45 (m, 2H), 7.45–7.38 (m, 1H), 4.49 (t, J = 5.2 Hz, 1H), 3.49 (td, J = 6.3, 5.2 Hz, 2H), 3.36 (q, J = 6.6 Hz, 2H), 1.71 (dq, J = 7.6, 6.4 Hz, 2H). LCMS RT (Method 1) = 3.920 min, m / z 373.1 [M+H + 。

[0319] Example 13

[0320] Synthesis of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide

[0321]

[0322] A mixture of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (50.0 mg, 0.159 mmol) and HATU (72.3 mg, 0.190 mmol) in DMF (2.00 mL) was stirred for 10 minutes, and then 7 equivalents of ammonia in MeOH (0.200 mL, 1.40 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (0.069 mL, 0.396 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was triturated in EtOH, filtered and air-dried to give 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (25.0 mg, 0.080 mmol, 50.2% yield) as a pale yellow-gold solid. 1 H NMR (400 MHz, DMSO-d6) δ 9.29 (d, J = 1.5 Hz, 1H), 8.75 (dd, J = 1.6, 0.9 Hz, 1H), 8.15–8.03 (m, 8H), 7.49 (tq, J = 6.2, 1.4 Hz, 3H), 7.45–7.39 (m, 1H). LCMS RT (Method 1) = 4.038 min, m / z 651.7 [2M+Na + , 315.9 [M+H + .

[0323] Example 14

[0324] Synthesis of 2-chloro-5-hydrazinopyrazine

[0325]

[0326] Hydrazine (0.211 ml, 6.71 mmol) was added to a solution of 2,5-dichloropyrazine (1.00 g, 6.71 mmol) in EtOH (20.0 mL). The resulting reaction mixture was stirred at 80 °C for 2 h, after which LC-MS analysis showed completion. The reaction mixture was cooled to room temperature and the product was precipitated. The mixture was poured into ice H2O, stirred vigorously for 5 minutes, filtered, rinsed with H2O and air-dried to give 2-chloro-5-hydrazinopyrazine (885 mg, 6.12 mmol, 91% yield) as a white powder, which was used without further purification. 1 H NMR (400 MHz, DMSO-d6) δ 8.16 (s, 1H), 8.04 (s, 1H), 7.93 (s, 1H), 4.32 (s, 2H).

[0327] Example 15

[0328] Synthesis of methyl 4-(2-(5-chloropyrazin-2-yl)hydrazine-1-carbonyl)benzoate

[0329]

[0330] To a solution of 2-chloro-5-hydrazinopyrazine (260 mg, 1.80 mmol), 4-(methoxycarbonyl)benzoic acid (405 mg, 2.25 mmol) and DIPEA (0.942 mL, 5.40 mmol) in DMF (5.00 mL) was added a solution of 50% propylphosphonic anhydride (T3P) in DMF (1.58 mL, 2.70 mmol). The resulting reaction mixture was stirred at room temperature for 1 h, after which LC-MS analysis showed completion. The reaction mixture was poured into ice H2O, stirred for 10 min, and the product was collected by filtration, washed thoroughly with H2O and air-dried to give methyl 4-(2-(5-chloropyrazin-2-yl)hydrazine-1-carbonyl)benzoate as a pale yellow solid, which was used without further purification. 1 1H NMR (400 MHz, DMSO-d6) δ 10.75 (s, 1H), 9.33 (s, 1H), 8.21 (d, J = 1.4 Hz, 1H), 8.12–8.06 (m, 2H), 8.06–7.99 (m, 2H), 7.94 (d, J = 1.4 Hz, 1H), 3.90 (s, 3H). LCMS RT (method 2) = 2.784 min, m / z 306.8 [M + +.

[0331] Example 16

[0332] Synthesis of methyl 4-(6-chloro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoate

[0333]

[0334] Perchloroethane (232 mg, 0.978 mmol) was added to a flask equipped with A suspension of methyl 4-(2-(5-chloropyrazin-2-yl)hydrazine-1-carbonyl)benzoate (150 mg, 0.489 mmol), triphenylphosphine (257 mg, 0.978 mmol) and DIPEA (0.342 mL, 1.96 mmol) in MS in ACN (5.00 mL). The resulting reaction mixture was stirred at 80 °C for 2 h, after which LCMS analysis showed completion. The reaction mixture was cooled to room temperature, filtered through celite and the cake was washed thoroughly with EtOAc. The filtrate was concentrated under reduced pressure and the residue was purified by flash column chromatography: silica gel, gradient 20 - 60% EtOAc / Hex to give methyl 4-(6-chloro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoate (105 mg, 0.364 mmol, 74.4% yield). 1 H NMR (400 MHz, DMSO-d6) δ 9.46 (d, J = 1.5 Hz, 1H), 8.94 (d, J = 1.5 Hz, 1H), 8.19 (d, J = 2.5 Hz, 2H), 8.17 (d, J = 2.7 Hz, 2H), 3.93 (s, 3H). LCMS RT (method 2) = 2.972 min, m / z 600.6 [2M+Na + , 289.9 [M + .

[0335] Example 17

[0336] Synthesis of methyl 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoate

[0337]

[0338] A mixture of methyl 4-(6-chloro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoate (40.0 mg, 0.139 mmol), phenylboronic acid (21.1 mg, 0.173 mmol), XPhosPd(crotyl)Cl (4.67 mg, 6.93 μmol) and K3PO4 (58.8 mg, 0.277 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 Dioxane:H2O (2.50 mL) was added and degassing was continued for 2 minutes, then the reaction vessel was placed in a preheated block at 100 °C. After stirring at 100 °C for 30 minutes, LCMS analysis showed completion. The reaction mixture was cooled to room temperature, partitioned between brine and EtOAc, filtered through celite and the layers were separated. The organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated to give crude methyl 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoate (38.0 mg, 0.115 mmol, 83% yield), which was used without further purification. LCMS RT (method 2) = 3.319 min, m / z 683.7 [2M+Na + .

[0339] Example 18

[0340] Synthesis of 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoic acid

[0341]

[0342] 2M Sodium hydroxide (1.00 mL, 2.00 mmol) was added to a solution of methyl 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoate (46.0 mg, 0.139 mmol) in EtOH (5.00 mL). The resulting reaction mixture was stirred at room temperature for 1 hour, after which LCMS analysis showed completion. The reaction mixture was concentrated to a slurry and the residue was partitioned between 1M HCl and EtOAc, the layers were separated, the organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated to give crude 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoic acid (44.0 mg, 0.139 mmol, 100% yield), which was used without further purification. LCMS RT (method 2) = 2.893 min, m / z 317.0 [M+H + .

[0343] Example 19

[0344] Synthesis of N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzamide (Compound 30)

[0345]

[0346] A mixture of 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzoic acid (44.0 mg, 0.139 mmol) and HATU (63.5 mg, 0.167 mmol) in DMF (1.50 mL) was stirred for 10 minutes, then 1-(3-aminopropyl)pyrrolidin-2-one (21.5 μL, 0.153 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (60.7 μL, 0.348 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0 - 20% MeOH / EtOAc to give N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)benzamide (24.0 mg, 0.054 mmol, 39.2% yield) as a pale yellow solid. 1 1H NMR (400 MHz, DMSO-d6) δ 9.63 (d, J = 1.6 Hz, 1H), 8.92 (d, J = 1.6 Hz, 1H), 8.68 (t, J = 5.7 Hz, 1H), 8.20–8.15 (m, 2H), 8.14–8.09 (m, 4H), 7.56–7.50 (m, 2H), 7.49–7.43 (m, 1H), 3.37 (t, J = 7.1 Hz, 2H), 3.32–3.23 (m, 4H), 2.24 (dd, J = 8.3, 7.8 Hz, 2H), 1.98–1.89 (m, 2H), 1.75 (p, J = 7.0 Hz, 2H). LCMS RT (Method 1) = 4.130 min, m / z 882.3 [2M+H + , 441.1 [M+H + .

[0347] Example 20

[0348] Synthesis of 5-bromo-2-hydrazinopyridine

[0349]

[0350] A solution of 5-bromo-2-fluoropyridine (1.00 mL, 9.72 mmol) and hydrazine (1.52 mL, 48.6 mmol) in EtOH (10.0 mL) was stirred at 100 °C for 1 h, after which LCMS analysis showed completion. The reaction volume was halved and the mixture was cooled to room temperature, and the product precipitated. The slurry was poured into ice H2O and stirred for 5 min, and the product was filtered, rinsed with H2O and air-dried to give 5-bromo-2-hydrazinopyridine (1.60 g, 8.51 mmol, 88% yield) as an off-white fluffy solid, which was used without further purification. 1 1H NMR (400 MHz, DMSO-d6) δ 8.02 (dd, J = 2.6, 0.7 Hz, 1H), 7.65 (s, 1H), 7.58 (dd, J = 8.9, 2.5 Hz, 1H), 6.69 (dd, J = 9.0, 0.7 Hz, 1H), 4.15 (s, 2H). LCMS RT (Method 2) = 1.150 min, m / z 189.3 [M+H + .

[0351] Example 21

[0352] Synthesis of methyl 4-(2-(5-bromopyridin-2-yl)hydrazine-1-carbonyl)benzoate

[0353]

[0354] To a solution of 5-bromo-2-hydrazinopyridine (500 mg, 2.66 mmol), 4-(methoxycarbonyl)benzoic acid (599 mg, 3.32 mmol) and DIPEA (1.39 mL, 7.98 mmol) in DMF (5.00 mL) was added a solution of 50% propylphosphonic anhydride (T3P) in DMF (2.33 mL, 3.99 mmol). The resulting reaction mixture was stirred at room temperature for 1 h, after which LCMS analysis showed completion. The reaction mixture was poured into ice H2O, stirred for 10 min, and the product was collected by filtration, rinsed thoroughly with H2O and air-dried to give methyl 4-(2-(5-bromopyridin-2-yl)hydrazine-1-carbonyl)benzoate (906 mg, 2.59 mmol, 97% yield) as a brown solid, which was used without further purification. 11H NMR (400 MHz, DMSO-d6) δ 10.61 (d, J = 1.9 Hz, 1H), 8.80 (d, J = 1.9 Hz, 1H), 8.15 (dd, J = 2.5, 0.7 Hz, 1H), 8.10–8.05 (m, 2H), 8.05–8.00 (m, 2H), 7.71 (dd, J = 8.9, 2.5 Hz, 1H), 6.66 (dd, J = 8.9, 0.7 Hz, 1H), 3.89 (d, J = 2.5 Hz, 3H). LCMS RT (Method 2) = 2.863 min, m / z 352.3 [M+H + .

[0355] Example 22

[0356] Synthesis of methyl 4-(6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoate

[0357]

[0358] Perchloroethane (946 mg, 4.00 mmol) was added to a suspension of methyl 4-(2-(5-bromopyridin-2-yl)hydrazine-1-carbonyl)benzoate (700 mg, 1.99 mmol), triphenylphosphine (1.05 g, 4.00 mmol) and DIPEA (1.39 mL, 8.00 mmol) in ACN (10.00 mL) with MS. The resulting reaction mixture was stirred at 80 °C for 2 h, after which LCMS analysis showed completion. The reaction mixture was cooled to room temperature, filtered through celite and the cake was washed thoroughly with EtOAc. The filtrate was concentrated under reduced pressure and the residue was purified by flash column chromatography: silica gel, gradient 20-80% EtOAc / Hex to give methyl 4-(6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoate (604 mg, 1.818 mmol, 91% yield). LCMS RT (Method 2) = 3.004 min, m / z 333.7 [M+H + .

[0359] Example 23

[0360] Synthesis of methyl 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoate

[0361]

[0362] A mixture of methyl 4-(6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoate (300 mg, 0.903 mmol), phenylboronic acid (138 mg, 1.13 mmol), XPhos Pd(crotyl)Cl (30.4 mg, 0.045 mmol) and K3PO4 (383 mg, 1.81 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 Dioxane:H2O (10.0 mL) was added and degassing was continued for 2 minutes, then the reaction vessel was placed in a preheated block at 100 °C. After stirring at 100 °C for 30 minutes, LC-MS analysis showed completion. The reaction mixture was cooled to room temperature, partitioned between brine and EtOAc, filtered through Celite and the layers were separated. The organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 40 - 100% EtOAc / Hex to give methyl 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoate (290 mg, 0.880 mmol, 97% yield) as an off-white solid. LCMS RT (Method 2) = 3.156 min, m / z 330.1 [M+H + .

[0363] Example 24

[0364] Synthesis of 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoic acid

[0365]

[0366] A suspension of methyl 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoate (290 mg, 0.880 mmol) in EtOH (8.00 mL) was treated with 2 M sodium hydroxide (2.00 mL, 4.00 mmol). The resulting reaction mixture was stirred at room temperature for 30 minutes, after which the solution became clear and LCMS analysis showed completion. The reaction mixture was concentrated to a slurry and poured into cold 1 M HCl solution and stirred vigorously for 10 minutes. The insoluble product was filtered, washed with H2O and air dried to give 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoic acid (248 mg, 0.786 mmol, 89% yield) as an off-white solid which was used without further purification. LCMS RT (Method 2) = 2.956 min, m / z 316.8 [M+H + .

[0367] Example 25

[0368] Synthesis of N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzamide (Compound 31)

[0369]

[0370] A mixture of 4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzoic acid (100 mg, 0.317 mmol) and HATU (145 mg, 0.381 mmol) in DMF (2.00 mL) was stirred for 10 minutes, then 1-(3-aminopropyl)pyrrolidin-2-one (0.049 mL, 0.349 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (0.138 mL, 0.793 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0 - 30% MeOH / EtOAc to give N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)benzamide (33.0 mg, 0.075 mmol, 23.68% yield) as a white solid. 1 1H NMR (400 MHz, DMSO-d6) δ 8.68–8.61 (m, 2H), 8.14–8.10 (m, 2H), 8.08 (d, J = 8.8 Hz, 2H), 7.99 (dd, J = 9.6, 1.0 Hz, 1H), 7.85–7.74 (m, 3H), 7.54–7.48 (m, 2H), 7.47–7.41 (m, 1H), 3.40–3.34 (m, 2H), 3.27 (q, J = 6.9 Hz, 4H), 2.23 (dd, J = 8.6, 7.5 Hz, 2H), 2.01–1.87 (m, 2H), 1.74 (p, J = 7.0 Hz, 2H). LCMS RT (Method 1) = 4.071 min, m / z 440.1 [M+H + .

[0371] Example 26

[0372] Synthesis of methyl 4-((2-chloro-5-nitropyridin-4-yl)amino)benzoate

[0373]

[0374] A mixture of 2-chloro-5-nitropyridin-4-amine (200 mg, 1.152 mmol), methyl 4-iodobenzoate (302 mg, 1.152 mmol), copper(I) iodide (32.9 mg, 0.173 mmol) and cesium carbonate (563 mg, 1.73 mmol) was placed in a vial, sealed and purged with N2 for 3 minutes. DMF (4.00 mL) was added and the reaction mixture was purged by bubbling N2 through the mixture for 3 minutes. The resulting reaction mixture was placed in a reaction block preheated to 120 °C and stirred for 16 hours, after which LCMS analysis showed product formation. The reaction mixture was partitioned between EtOAc and H2O, filtered through celite, the layers were separated, the organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated. The crude residue was purified by flash column chromatography: silica gel, gradient 10 - 30% EtOAc / Hex to give methyl 4-((2-chloro-5-nitropyridin-4-yl)amino)benzoate (84.0 mg, 0.273 mmol, 23.69% yield). 1 1H NMR (400 MHz, DMSO-d6) δ 10.04 (s, 1H), 8.99 (s, 1H), 8.08–8.00 (m, 2H), 7.57–7.49 (m, 2H), 7.03 (s, 1H), 3.87 (s, 3H). LCMS RT (method 2) = 3.334 min, m / z 308.0 [M+H + .

[0375] Example 27

[0376] Synthesis of methyl 4-((5-amino-2-chloropyridin-4-yl)amino)benzoate

[0377]

[0378] A mixture of methyl 4-((2-chloro-5-nitropyridin-4-yl)amino)benzoate (80.0 mg, 0.260 mmol), iron powder (72.6 mg, 1.30 mmol) and ammonium chloride (278 mg, 5.20 mmol) in 1:1 EtOH-H2O (10.0 mL) was stirred at 70 °C for 1 hour, after which LCMS analysis showed completion. The reaction mixture was cooled to room temperature and partitioned between brine and EtOAc, filtered through celite and the layers were separated. The organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated to give crude methyl 4-((5-amino-2-chloropyridin-4-yl)amino)benzoate (70.0 mg, 0.252 mmol, 97% yield) as a brown solid which was used without further purification. LCMS RT (method 2) = 2.573 min, m / z 278.0 [M+H + .

[0379] Example 28

[0380] Synthesis of methyl 4-(6-chloro-1H-imidazo[4,5-c]pyridin-1-yl)benzoate

[0381]

[0382] A solution of methyl 4-((5-amino-2-chloropyridin-4-yl)amino)benzoate (65.0 mg, 0.234 mmol), triethyl orthoformate (0.100 mL, 0.601 mmol), and catalytic p-toluenesulfonic acid (p-TsOH) (6.68 mg, 0.035 mmol) in THF (5.00 mL) was stirred overnight at 60 °C, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc and washed with saturated NaHCO3, brine, dried over anhydrous MgSO4, filtered, and concentrated. The crude residue was purified by flash column chromatography: silica gel, gradient 20 - 80% EtOAc / HEX to give methyl 4-(6-chloro-1H-imidazo[4,5-c]pyridin-1-yl)benzoate (41.0 mg, 0.143 mmol, 60.9% yield) as a white powder. 1 1H NMR (400 MHz, chloroform-d) δ 8.97 (d, J = 0.9 Hz, 1H), 8.34–8.28 (m, 2H), 8.22 (s, 1H), 7.61–7.58 (m, 2H), 7.54 (d, J = 0.9 Hz, 1H), 4.00 (s, 3H). LCMS RT (method 2) = 3.034 min, m / z 287.8 [M + +.

[0383] Example 29

[0384] Synthesis of 4-(6-phenyl-1H-imidazo[4,5-c]pyridin-1-yl)benzoic acid

[0385]

[0386] A mixture of methyl 4-(6-chloro-1H-imidazo[4,5-c]pyridin-1-yl)benzoate (35.0 mg, 0.122 mmol), phenylboronic acid (18.54 mg, 0.152 mmol), XPhos Pd(crotyl)Cl (4.10 mg, 6.08 μmol) and K3PO4 (51.6 mg, 0.243 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 Dioxane:H2O (2.50 mL) was added and degassing continued for 2 minutes, then the reaction vessel was placed in a preheated block at 100 °C. After stirring at 100 °C for 30 minutes, LCMS analysis showed completion. The reaction mixture was then treated with 2 M sodium hydroxide (0.500 mL, 1.00 mmol) and stirring continued at 100 °C for 30 minutes, after which LCMS analysis showed complete saponification of the ester. The reaction mixture was cooled to room temperature and diluted with EtOAc and H2O. The pH was adjusted to ~4 - 5 with AcOH, the biphasic mixture was filtered through Celite, the layers were separated and the organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated to give crude 4-(6-phenyl-1H-imidazo[4,5-c]pyridin-1-yl)benzoic acid (35.0 mg, 0.111 mmol, 91% yield), which was used without further purification. LCMS RT (method 2) = 2.601 min, m / z 315.8 [M + .

[0387] Example 30

[0388] Synthesis of N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-1H-imidazo[4,5-c]pyridin-1-yl)benzamide (Compound 32)

[0389]

[0390] A mixture of 4-(6-phenyl-1H-imidazo[4,5-c]pyridin-1-yl)benzoic acid (40.0 mg, 0.127 mmol) and HATU (57.9 mg, 0.152 mmol) in DMF (1.50 mL) was stirred for 10 minutes, then 1-(3-aminopropyl)pyrrolidin-2-one (19.57 μL, 0.140 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (55.4 μL, 0.317 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0 - 20% MeOH / EtOAc to give N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-1H-imidazo[4,5-c]pyridin-1-yl)benzamide (32.0 mg, 0.073 mmol, 57.4% yield) as an off-white solid. 1 1H NMR (400 MHz, DMSO-d6) δ 9.17 (d, J = 1.0 Hz, 1H), 8.82 (s, 1H), 8.65 (t, J = 5.7 Hz, 1H), 8.19–8.08 (m, 5H), 7.97–7.88 (m, 2H), 7.51–7.44 (m, 2H), 7.43–7.37 (m, 1H), 3.37 (t, J = 7.0 Hz, 2H), 3.28 (dt, J = 15.9, 6.9 Hz, 4H), 2.24 (dd, J = 8.6, 7.4 Hz, 2H), 1.94 (ddd, J = 15.4, 13.1, 6.4 Hz, 2H), 1.75 (p, J = 7.1 Hz, 2H). LCMS RT (Method 1) = 3.523 min, m / z 440.8 [M+H + .

[0391] Example 31

[0392] Synthesis of methyl 4-(6-chloro-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoate

[0393]

[0394] A mixture of 6-chloro-1H-pyrrolo[3,2-c]pyridine (200 mg, 1.31 mmol), methyl 4-iodobenzoate (343 mg, 1.31 mmol), copper(I) iodide (37.4 mg, 0.197 mmol), and cesium carbonate (641 mg, 1.97 mmol) was placed in a vial, sealed and purged with N2 for 3 minutes. DMF (4.00 mL) was added and the reaction mixture was purged by bubbling N2 through the mixture for 3 minutes. The resulting reaction mixture was placed in a preheated reaction block at 120 °C and stirred for 16 hours, after which LCMS analysis showed product formation. The reaction mixture was partitioned between EtOAc and H2O, filtered through celite, the layers were separated, the organic phase was washed with brine, dried over anhydrous MgSO4, filtered, and concentrated. The crude residue was purified by flash column chromatography: silica gel, gradient 5-35% EtOAc / Hex to give methyl 4-(6-chloro-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoate (213 mg, 0.743 mmol, 56.7% yield). LCMS RT (method 2) = 3.247 min, m / z 287.0 [M+H + .

[0395] Example 32

[0396] Synthesis of methyl 4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoate

[0397]

[0398] A mixture of methyl 4-(6-chloro-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoate (100 mg, 0.349 mmol), phenylboronic acid (53.2 mg, 0.436 mmol), XPhosPd(crotyl)Cl (11.75 mg, 0.017 mmol), and K3PO4 (148 mg, 0.698 mmol) was placed in a vial and purged with N2 for 2 minutes. 4:1 dioxane:H2O (2.50 mL) was added and degassing continued for 2 minutes, then the reaction vessel was placed in a preheated block at 100 °C. After stirring at 100 °C for 30 minutes, LCMS analysis showed completion. The reaction mixture was cooled to room temperature, partitioned between brine and EtOAc, filtered through celite and the layers were separated. The organic phase was washed with brine, dried over anhydrous MgSO4, filtered, and concentrated. The crude product was purified by flash column chromatography: silica gel, gradient 10-35% EtOAc / Hex to give methyl 4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoate (110 mg, 0.335 mmol, 96% yield). LCMS RT (method 2) = 2.795 min, m / z 329.1 [M+H + .

[0399] Example 33

[0400] Synthesis of 4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoic acid

[0401]

[0402] 2M sodium hydroxide (2.00 mL, 4.00 mmol) was added to a solution of methyl 4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoate (100 mg, 0.305 mmol) in EtOH (5.00 mL). The resulting reaction mixture was stirred at room temperature for 2 h, after which LCMS analysis showed completion. The reaction mixture was concentrated to a slurry and the residue was partitioned between 1M HCl and EtOAc, the layers were separated, the organic phase was washed with brine, dried over anhydrous MgSO4, filtered and concentrated to give crude 4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoic acid (55.0 mg, 0.175 mmol, 57.5% yield), which was used without further purification. LCMS RT (Method 2) = 2.664 min, m / z 314.9 [M + .

[0403] Example 34

[0404] Synthesis of N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzamide (Compound 33)

[0405]

[0406] A mixture of 4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzoic acid (25.0 mg, 0.080 mmol) and HATU (36.3 mg, 0.095 mmol) in DMF (1.50 mL) was stirred for 10 minutes, then 1-(3-aminopropyl)pyrrolidin-2-one (12.3 μL, 0.087 mmol) was added. The resulting reaction mixture was stirred for 20 minutes, then DIPEA (34.7 μL, 0.199 mmol) was added and the reaction was stirred overnight, after which LCMS analysis showed completion. The reaction mixture was diluted with EtOAc, washed with H2O and brine, dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by flash column chromatography: silica gel, gradient 0 - 20% MeOH / EtOAc to give N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenyl-1H-pyrrolo[3,2-c]pyridin-1-yl)benzamide (17.0 mg, 0.039 mmol, 48.7% yield) as an off-white solid. 1 1H NMR (400 MHz, DMSO-d6) δ 9.04 (s, 1H), 8.62 (t, J = 5.6 Hz, 1H), 8.10 (t, J = 7.4 Hz, 4H), 8.02 (s, 1H), 7.88 (d, J = 3.4 Hz, 1H), 7.83 (d, J = 8.4 Hz, 2H), 7.46 (t, J = 7.5 Hz, 2H), 7.37 (t, J = 7.2 Hz, 1H), 6.93 (d, J = 3.3 Hz, 1H), 3.37 (t, J = 7.0 Hz, 2H), 3.27 (q, J = 7.1, 6.6 Hz, 4H), 2.23 (t, J = 8.1 Hz, 2H), 1.93 (p, J = 7.5 Hz, 2H), 1.74 (p, J = 7.1 Hz, 2H). LCMS RT (Method 1) = 3.521 min, m / z 439.1 [M+H + .

[0407] Example 35

[0408] Synthesis of methyl 4-(((5-phenylpyrazin-2-yl)methyl)carbamoyl)benzoate

[0409]

[0410] A heterogeneous solution consisting of (5-phenylpyrazin-2-yl)methanamine (key organic compound) (3.3 g, 17.82 mmol), 4-(methoxycarbonyl)benzoic acid (3.53 g, 19.60 mmol), HOBt (3.55 g, 23.16 mmol), DIPEA (9.33 ml, 53.4 mmol) in DMF (100 ml) was stirred at 65 °C for 1 minute under N2. EDC (4.10 g, 21.38 mmol) was added to the solution. The solution was stirred at 65 °C for 2.5 hours under N2. The solution was cooled to room temperature. Water (500 ml) was added to the solution. The solution was cooled for 18 hours. The solution was filtered. The solid was washed with water (3x), dried in air and then in vacuo to give the desired compound (5.4 g, 87%). (LCMS, ESI pos.) Calculated for C 20 H 17 N3O3: 348.4 (M+H), measured: 348.1. 1 1H NMR (400 MHz, DMSO-d6) δ 9.43 (t, J = 5.7 Hz, 1H), 9.23 (d, J = 1.5 Hz, 1H), 8.76 (d, J = 1.5 Hz, 1H), 8.19–8.14 (m, 2H), 8.13–8.05 (m, 4H), 7.61–7.50 (m, 3H), 4.72 (d, J = 5.7 Hz, 2H), 3.93 (s, 3H).

[0411] Example 36

[0412] Synthesis of methyl 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoate

[0413]

[0414] A heterogeneous solution of methyl 4-(((5-phenylpyrazin-2-yl)methyl)carbamoyl)benzoate (2.5 g, 7.7 mmol) and pyridine (3.49 ml, 43.2 mmol) in DCE (72.0 ml) was treated dropwise with POCl3 (28.8 ml) over 1 minute. The heterogeneous solution was stirred at 70 °C under N2. The solution was stirred at 70 °C for 5 hours. The reaction was cooled to room temperature. The solution was cooled (ice bath). MeOH (10 ml) was slowly added to the solution. The solution was concentrated to a small volume and chromatographed using gradient silica gel chromatography (5% EtOAc / hexane to 100% EtOAc over 20 minutes). The desired fractions were combined, concentrated and dried in vacuo to give the desired compound (1.8 g, 76%). (LCMS, ESI pos.) Calculated for C 20 H 15N3O2: 330.4 (M+H), Measured: 330.1. 1 1H NMR (400 MHz, DMSO-d6) δ 9.34 (d, J = 1.5 Hz, 1H), 8.82 (t, J = 1.3 Hz, 1H), 8.21 (d, J = 1.1 Hz, 4H), 8.15–8.08 (m, 3H), 7.59–7.49 (m, 2H), 7.49–7.42 (m, 1H), 3.95 (d, J = 1.2 Hz, 3H).

[0415] Example 37

[0416] Synthesis of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid

[0417]

[0418] To a solution of methyl 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoate (1.8 g, 5.47 mmol) in MeOH / THF 1:1 (40 ml) was added sodium hydroxide (10.93 ml, 10.93 mmol). The solution was stirred at room temperature under N2. After 3 h, the reaction solution was concentrated to a small volume. The solution was cooled using an ice / water bath. The pH was adjusted to 2 (litmus) using 1N HCl (added slowly). The solution was placed in the refrigerator overnight. The solution was filtered. The solid was washed with water (3x). The solid was dried in air and then in vacuo to give the desired product (1.0 g, 58%). (LCMS, ESI pos.) Calculated for C 19 H 13 N3O2: 316.3 (M+H), Measured: 316.1. 1 1H NMR (400 MHz, DMSO-d6) δ 13.23 (s, 1H), 9.27 (s, 1H), 8.75 (s, 1H), 8.07 (m, J = 21.4 Hz, 7H), 7.43 (m, J = 23.8 Hz, 3H).

[0419] Example 38

[0420] Synthesis of N-(2-(1H-imidazol-5-yl)ethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 1)

[0421]

[0422] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (1 g, 3.17 mmol) in DMF (10.57 ml) with DIPEA (1.108 ml, 6.34 mmol). Add HATU (1.326 g, 3.49 mmol) to the solution. Stir the solution at room temperature under N2. After 30 minutes, add histamine (0.388 g, 3.49 mmol) to the solution. Stir the reaction solution at room temperature under N2 for 18 hours. Add 1N NaOH (1.9 mmol) to the reaction solution. Concentrate the solution to a small volume after 30 minutes. Partition the solution between EtOAc and water. Separate the EtOAc layer and wash it successively with water (2x), brine (1x), dry over anhydrous MgSO4, filter and concentrate. Chromatograph the residue using C18 reverse phase chromatography to give the desired compound (0.7 g, 54%). (LCMS, ESI pos.) Calculated for C 24 H 20 N6O: 409.5 (M+H), measured: 409.2. 1 1H NMR (400 MHz, DMSO-d6) δ 11.87 (s, 1H), 9.33 (d, J = 1.5 Hz, 1H), 8.84–8.71 (m, 2H), 8.22–8.03 (m, 7H), 7.69–7.40 (m, 4H), 6.90 (s, 1H), 3.57 (td, J = 7.5, 5.5 Hz, 2H), 2.83 (s, 2H).

[0423] Figure 15 The IC50 of compound 1 was shown to be 2.86 μM.

[0424] As Figures 10A to 10C shown in and Table 1, when administered by both oral and intraperitoneal injection routes, different concentrations of compound 1 showed excellent PK profiles in plasma, liver and pancreas.

[0425] Table 1

[0426]

[0427] Example 39

[0428] Synthesize N-(3-(2-oxopyrrolidin-1-yl)propyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 28)

[0429]

[0430] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.255 g, 0.809 mmol) and HATU (0.369 g, 0.970 mmol) in DMF (2.70 ml) with DIPEA (0.282 ml, 1.617 mmol). Stir the solution at room temperature under N2. After 20 minutes, add a solution of 1-(3-aminopropyl)pyrrolidin-2-one (0.126 g, 0.890 mmol) in DMF (0.1 ml) to the solution. Stir the reaction solution at room temperature under N2. After 18 hours, introduce the reaction solution into a C18 column (15.5 g, equilibrated with water) and purify using a gradient (0 - 30% CH3CN, 20 minutes) to obtain the desired compound (0.142 g, 40%). (LCMS, ESI pos.) Calculated for C 26 H 25 N5O2: 440.5 (M+H), measured: 440.2. 1 1H NMR (400 MHz, DMSO-d6) δ 9.34 (d, J = 1.5 Hz, 1H), 8.79 (t, J = 1.3 Hz, 1H), 8.66 (t, J = 5.7 Hz, 1H), 8.19–8.05 (m, 7H), 7.53 (dd, J = 8.3, 6.6 Hz, 2H), 7.49–7.43 (m, 1H), 3.41 (t, J = 7.0 Hz, 2H), 3.32 (dt, J = 14.0, 6.9 Hz, 4H), 2.27 (t, J = 8.1 Hz, 2H), 2.05–1.91 (m, 2H), 1.78 (p, J = 7.1 Hz, 2H).

[0431] Example 40

[0432] Synthesis of (3-hydroxyazetidin-1-yl)(4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)phenyl)methanone (Compound 17)

[0433]

[0434] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.317 ml) with DIPEA (0.033 ml, 0.190 mmol). After 10 minutes, azetidin-3-ol (0.012 g, 0.159 mmol) was added to the solution. The solution was stirred overnight at room temperature. The solution was introduced into a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The desired fractions were combined, concentrated and dried in vacuo to give the desired compound (0.04 g, 68%). (LCMS, ESI pos.) Calculated for C 22 H 18 N4O2: 371.4 (M+H), found: 371.2. 1 H NMR (400 MHz, DMSO-d6) δ 9.33 (d, J = 1.5 Hz, 1H), 8.81–8.76 (m, 1H), 8.57 (dd, J = 8.4, 1.4 Hz), 8.16–8.06 (m, 4H), 7.91–7.84 (m, 2H), 7.57–7.49 (m, 2H), 7.49–7.43 (m, 1H), 5.83 (s, 1H), 4.57 (d, J = 5.1 Hz, 2H), 4.33 (s, 1H), 4.16 (s, 1H), 3.94–3.84 (m, 1H), 1.29 (td, J = 7.1, 5.1 Hz, 3H).

[0435] Example 41

[0436] Synthesis of (4-hydroxypiperidin-1-yl)(4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)phenyl)methanone (Compound 18)

[0437]

[0438] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) with DIPEA (0.033 ml, 0.190 mmol). Stir the solution at room temperature for 10 minutes. Add piperidin-4-ol (0.016 g, 0.159 mmol) to the solution. Stir the solution at room temperature overnight. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry in vacuo to give the desired compound (0.03 g, 48%). (LCMS, ESI pos.) Calculated for C 24 H 22 N4O2: 399.5 (M+H), measured: 399.2. 1 1H NMR (400 MHz, DMSO-d6) δ 9.32 (d, J = 1.5 Hz, 1H), 8.80 (t, J = 1.2 Hz, 1H), 8.16–8.05 (m, 5H), 7.70–7.58 (m, 2H), 7.58–7.42 (m, 3H), 4.86 (s, 1H), 3.86–3.76 (m, 1H), 3.63 (s, 1H), 3.28 (s, 3H), 1.82 (s, 2H), 1.44 (s, 3H).

[0439] Example 42

[0440] Synthesis of N-(2-(dimethylamino)ethyl)-N-methyl-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 19)

[0441]

[0442] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) with DIPEA (0.033 ml, 0.190 mmol). After 10 minutes, add N1,N1,N2-trimethylethane-1,2-diamine (0.021 ml, 0.159 mmol). Stir the solution at room temperature overnight. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry in vacuo to give the desired compound (0.03 g, 47%). (LCMS, ESI pos.) Calculated for C 24 H 25N5O: 400.5 (M+H), Measured: 400.2. 1 H NMR (400 MHz, DMSO-d6) δ 9.10 (d, J = 1.5 Hz, 1H), 8.41 (t, J = 1.2 Hz, 1H), 7.93 (d, J = 1.0 Hz, 1H), 7.87 (td, J = 6.1, 2.8 Hz, 4H), 7.66–7.59 (m, 2H), 7.52–7.44 (m, 2H), 7.43–7.37 (m, 1H), 3.68 (s, 1H), 3.40 (d, J = 10.2 Hz, 1H), 3.09 (d, J = 29.0 Hz, 3H), 2.67–2.38 (m, 2H), 2.32 (s, 3H), 2.10 (s, 3H).

[0443] Example 43

[0444] Synthesis of N-(4-acetamidophenyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 5)

[0445]

[0446] A solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) was treated with DIPEA (0.033 ml, 0.190 mmol). After 10 minutes, N-(4-aminophenyl)acetamide (0.024 g, 0.159 mmol) was added to the solution. The solution was stirred at room temperature. After 18 hours, the solution was introduced into a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The required fractions were combined, concentrated and dried in vacuo to give the required compound (0.04 g, 56%). (LCMS, ESI pos.) Calculated for C 27 H 21 N5O2: 448.5 (M+H), Measured: 448.2. 11H NMR (400 MHz, chloroform-d) δ 9.10 (d, J = 1.5 Hz, 1H), 8.41 (t, J = 1.2 Hz, 1H), 7.93 (d, J = 1.0 Hz, 1H), 7.87 (td, J = 6.1, 2.8 Hz, 4H), 7.66–7.59 (m, 2H), 7.52–7.44 (m, 2H), 7.43–7.37 (m, 1H), 3.68 (s, 1H), 3.40 (d, J = 10.2 Hz, 1H), 3.09 (d, J = 29.0 Hz, 3H), 2.67–2.38 (m, 2H), 2.32 (s, 3H), 2.10 (s, 3H).

[0447] Figure 5 The IC50 of compound 5 was shown to be 7.36 μM.

[0448] Example 44

[0449] Synthesis of N-(3-(1H-imidazol-1-yl)propyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 6)

[0450]

[0451] A solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) was treated with DIPEA (0.033 ml, 0.190 mmol). The solution was stirred for 15 minutes. 3-(1H-Imidazol-1-yl)propan-1-amine (0.020 g, 0.159 mmol) was added to the solution. The solution was stirred at room temperature. The solution was applied to a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The desired fractions were combined, concentrated and dried in vacuo to give the desired compound (0.03 g, 45%). (LCMS, ESI pos.) Calculated for C 25 H 22 N6O: 423.5 (M+H), measured: 423.1. 11H NMR (400 MHz, chloroform-d) δ 9.11 (d, J = 1.6 Hz, 1H), 8.43 (dd, J = 1.6, 0.9 Hz, 1H), 7.93 (s, 5H), 7.89–7.83 (m, 2H), 7.51 (t, J = 1.1 Hz, 1H), 7.50–7.43 (m, 2H), 7.43–7.37 (m, 1H), 7.06 (d, J = 1.1 Hz, 1H), 6.98 (t, J = 1.3 Hz, 1H), 6.60–6.49 (m, 1H), 4.09 (dt, J = 11.4, 7.0 Hz, 2H), 3.51 (q, J = 6.5 Hz, 2H), 2.15 (p, J = 6.8 Hz, 2H).

[0452] Figure 6 The IC50 of compound 6 was shown to be 3.85 μM.

[0453] Example 45

[0454] Synthesis of N-(2-(dimethylamino)ethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 7)

[0455]

[0456] A solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) was treated with DIPEA (0.033 ml, 0.190 mmol). N1,N1-Dimethylethane-1,2-diamine (0.017 ml, 0.159 mmol) was added to the solution. The solution was stirred overnight at room temperature. The solution was applied to a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The desired fractions were combined, concentrated, and dried in vacuo to give the desired compound (0.045 g, 74%). (LCMS, ESI pos.) Calculated for C 23 H 23 N5O: 386.5 (M+H), measured: 385.9. 11H NMR (400 MHz, chloroform-d) δ 9.11 (d, J = 1.6 Hz, 1H), 8.44 (dd, J = 1.7, 0.9 Hz, 1H), 8.00 (d, J = 8.4 Hz, 2H), 7.96–7.91 (m, 3H), 7.90–7.85 (m, 2H), 7.50–7.44 (m, 2H), 7.44–7.37 (m, 1H), 6.96 (s, 1H), 3.61–3.51 (m, 2H), 2.54 (t, J = 5.9 Hz, 2H), 2.28 (s, 6H).

[0457] Figure 7 The IC50 of compound 7 was shown to be 3.13 μM.

[0458] Example 46

[0459] Synthesis of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)-N-(pyrazin-2-ylmethyl)benzamide (Compound 20)

[0460]

[0461] A solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) was treated with DIPEA (0.033 ml, 0.190 mmol). Pyrazin-2-ylmethanamine (0.017 g, 0.159 mmol) was added to the solution. The solution was stirred at room temperature for 18 h. The solution was applied to a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The desired fractions were combined, concentrated and dried in vacuo to give the desired compound (0.045 g, 74%). (LCMS, ESI pos.) Calculated for C 24 H 18 N6O: 407.5 (M+H), measured: 407.2. 1 1H NMR (400 MHz, chloroform-d) δ 9.10 (d, J = 1.6 Hz, 1H), 8.68 (d, J = 1.5 Hz, 1H), 8.56–8.48 (m, 2H), 8.42 (t, J = 1.3 Hz, 1H), 8.08–8.01 (m, 2H), 7.96–7.90 (m, 3H), 7.88–7.81 (m, 2H), 7.53 (t, J = 5.3 Hz, 1H), 7.48–7.34 (m, 3H), 4.84 (d, J = 5.1 Hz, 2H).

[0462] Example 47

[0463] Synthesis of 1-(4-(4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoyl)piperazin-1-yl)ethan-1-one (Compound 21)

[0464]

[0465] A solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) was treated with 1-(piperazin-1-yl)ethan-1-one (0.020 g, 0.159 mmol). The solution was stirred at room temperature for 18 h. The solution was applied to a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The required fractions were combined, concentrated and dried in vacuo to give the required compound (0.045 g, 74%). (LCMS, ESI pos.) Calculated for C 25 H 23 N5O2: 426.5 (M+H), found: 426.1. 1 H NMR (400 MHz, chloroform-d) δ 9.12 (d, J = 1.6 Hz, 1H), 8.49–8.36 (m, 1H), 7.96–7.90 (m, 3H), 7.90–7.84 (m, 2H), 7.65–7.60 (m, 2H), 7.51–7.44 (m, 2H), 7.44–7.38 (m, 1H), 3.93–3.33 (m, 8H), 2.13 (s, 3H).

[0466] Example 48

[0467] Synthesis of N-(2-methoxyethyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 22)

[0468]

[0469] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) with DIPEA (0.033 ml, 0.190 mmol). Stir the solution for 15 minutes. Add 2-methoxyethan-1-amine (0.014 ml, 0.159 mmol) to the solution. Stir the solution at room temperature for 18 hours. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry in vacuo to give the desired compound (0.040 g, 68%). (LCMS, ESI pos.) Calculated for C 22 H 20 N4O2: 373.4 (M+H), measured: 372.9. 1 1H NMR (400 MHz, chloroform-d) δ 9.12 (d, J = 1.6 Hz, 1H), 8.44 (t, J = 1.2 Hz, 1H), 8.02–7.92 (m, 5H), 7.90–7.85 (m, 2H), 7.47 (dd, J = 8.3, 6.5 Hz, 2H), 7.44–7.38 (m, 1H), 6.60 (s, 1H), 3.69 (q, J = 5.2 Hz, 2H), 3.59 (t, J = 5.0 Hz, 2H), 3.40 (s, 3H).

[0470] Example 49

[0471] Synthesis of N-methyl-1-(4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoyl)piperidine-4-carboxamide (Compound 23)

[0472]

[0473] Treat a solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) with DIPEA (0.033 ml, 0.190 mmol). Stir the solution at room temperature for 15 minutes. Add N-methylpiperidine-4-carboxamide (0.023 g, 0.159 mmol) to the solution. Stir the reaction solution at room temperature for 18 hours. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry in vacuo to give the desired compound (0.033 g, 47%). (LCMS, ESI pos.) Calculated for C 26 H25 N5O2: 440.5 (M+H), Measured: 439.9. 1 H NMR (400 MHz, chloroform-d) δ 9.08 (d, J = 1.5 Hz, 1H), 8.39 (p, J = 0.7 Hz, 1H), 7.90 (d, J = 0.9 Hz, 1H), 7.88–7.80 (m, 4H), 7.61–7.52 (m, 2H), 7.44 (dd, J = 8.3, 6.5 Hz, 2H), 7.41–7.34 (m, 1H), 5.84 (q, J = 4.9 Hz, 1H), 4.67 (s, 1H), 3.84 (s, 1H), 3.17–2.81 (m, 2H), 2.78 (d, J = 4.8 Hz, 3H), 2.35 (tt, J = 11.1, 4.1 Hz, 1H), 1.83 (d, J = 51.1 Hz, 4H).

[0474] Example 50

[0475] Synthesis of N-(4-hydroxycyclohexyl)-4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 24)

[0476]

[0477] A solution of 4-(6-phenylimidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.05 g, 0.159 mmol) and HATU (0.066 g, 0.174 mmol) in DMF (0.5 ml) was treated with DIPEA (0.033 ml, 0.190 mmol). The solution was stirred at room temperature. After 10 minutes, 4-aminocyclohexan-1-ol (0.018 g, 0.159 mmol) was added. The solution was stirred at room temperature for 18 hours. The solution was applied to a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The required fractions were combined, concentrated and dried in vacuo to give the required compound (0.032 g, 49%). (LCMS, ESI pos.) Calculated for C 25 H 24 N4O2: 413.5 (M+H), Measured: 412.9. 11H NMR (400 MHz, chloroform-d) δ 9.11 (d, J = 1.6 Hz, 1H), 8.42 (t, J = 1.3 Hz, 1H), 7.94 (dd, J = 3.4, 1.1 Hz, 5H), 7.89–7.83 (m, 2H), 7.50–7.43 (m, 2H), 7.43–7.37 (m, 1H), 6.00 (d, J = 7.9 Hz, 1H), 4.00 (tdt, J = 11.5, 8.0, 4.1 Hz, 1H), 3.66 (tt, J = 10.3, 4.1 Hz, 1H), 2.22–2.10 (m, 2H), 2.04 (dd, J = 12.0, 3.8 Hz, 2H), 1.58–1.41 (m, 2H), 1.34 (qd, J = 12.8, 3.1 Hz, 2H).

[0478] Example 51

[0479] Synthesis of 4-(6-(3-Fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)-N-(3-(2-oxopyrrolidin-1-yl)propyl)benzamide (Compound 29)

[0480]

[0481] A mixture of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.022 g, 0.066 mmol) and HATU (0.028 g, 0.073 mmol) in DMF (0.220 ml) was treated with DIPEA (0.014 ml, 0.079 mmol). The solution was stirred at room temperature. After 10 minutes, 1-(3-aminopropyl)pyrrolidin-2-one (9.39 mg, 0.066 mmol) was added. The solution was stirred at room temperature. The solution was stirred at room temperature for 3 hours. The solution was applied to a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The desired fractions were combined, concentrated and dried in vacuo to give the desired compound (0.007 g, 23%). (LCMS, ESI pos.) Calculated for C 26 H 24 FN5O2: 458.5 (M+H), measured: 458.1. 11H NMR (400 MHz, chloroform-d) δ 9.11 (d, J = 1.6 Hz, 1H), 8.46 (t, J = 1.3 Hz, 1H), 8.24–8.14 (m, 2H), 8.06 (t, J = 6.4 Hz, 1H), 8.02–7.91 (m, 3H), 7.72–7.60 (m, 2H), 7.43 (td, J = 8.2, 5.9 Hz, 1H), 7.10 (tdd, J = 8.3, 2.6, 1.0 Hz, 1H), 3.46 (ddt, J = 9.2, 6.1, 2.9 Hz, 6H), 2.57–2.42 (m, 2H), 2.23–2.05 (m, 2H), 1.90–1.77 (m, 2H).

[0482] Example 52

[0483] Synthesis of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 8)

[0484]

[0485] A mixture of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.02 g, 0.060 mmol) and HATU (0.025 g, 0.066 mmol) in DMF (0.200 ml) was treated with DIPEA (0.013 ml, 0.072 mmol). The solution was stirred at room temperature for 10 minutes. Ammonia (8.57 μl, 0.060 mmol) was added to the solution. The solution was stirred at room temperature for 18 hours. The solution was filtered. The solid was triturated with EtOAc / MeOH 1:1. The solution was decanted. The solid was dried in vacuo to give the desired compound (7.7 mg, 39%). (LCMS, ESI pos.) Calculated for C 19 H 13 FN4O: 333.3 (M+H), measured: 333.1. 1 1H NMR (400 MHz, chloroform-d) δ 8.96 (t, J = 1.2 Hz, 1H), 8.38 (d, J = 1.5 Hz, 1H), 7.90 (d, J = 8.1 Hz, 2H), 7.82 (d, J = 1.0 Hz, 1H), 7.74 (d, J = 8.1 Hz, 1H), 7.70 (d, J = 5.7 Hz), 7.53–7.47 (m, 2H), 7.20 (td, J = 7.9, 5.8 Hz, 1H), 6.91–6.82 (m, 1H), 6.76 (s, 1H).

[0486] Figure 20 The IC50 of Compound 8 was shown to be 0.45 μM.

[0487] Example 53

[0488] Synthesis of N-(3-(1H-imidazol-1-yl)propyl)-4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 25)

[0489]

[0490] A solution of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.02 g, 0.060 mmol) and HATU (0.025 g, 0.066 mmol) in DMF (0.200 ml) was treated with DIPEA (0.013 ml, 0.072 mmol). The solution was stirred at room temperature for 10 minutes. 3-(1H-Imidazol-1-yl)propan-1-amine (7.51 mg, 0.060 mmol) was added to the solution. The solution was stirred at room temperature for 18 hours. The solution was loaded onto a 24 g silica gel column equilibrated with EtOAc. Elution was carried out with a gradient (EtOAc to 10% MeOH / EtOAc). The desired fractions were combined, concentrated and dried in vacuo to give the desired compound (0.005 g, 19%). (LCMS, ESI pos.) Calculated for C 25 H 21 FN6O: 441.5 (M+H), measured: 441.1. 1 H NMR (400 MHz, chloroform-d) δ 9.08 (t, J = 1.2 Hz, 1H), 8.40 (dt, J = 1.6, 1.0 Hz, 1H), 8.02 (dd, J = 7.5, 1.3 Hz, 2H), 7.99–7.85 (m, 4H), 7.78 (s, 1H), 7.61 (dt, J = 8.8, 1.6 Hz, 2H), 7.48–7.36 (m, 1H), 7.09 (tdd, J = 6.4, 2.9, 1.5 Hz, 2H), 7.01 (s, 1H), 4.20–4.05 (m, 2H), 3.51 (q, J = 6.4 Hz, 2H), 2.18 (p, J = 6.6 Hz, 2H).

[0491] Example 54

[0492] Synthesis of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)-N-(2-methoxyethyl)benzamide (Compound 13)

[0493]

[0494] Treat a solution of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.02 g, 0.060 mmol) and HATU (0.025 g, 0.066 mmol) in DMF (0.200 ml) with DIPEA (0.013 ml, 0.072 mmol). Stir the solution at room temperature for 10 minutes. Add 2-methoxyethan-1-amine (5.22 μl, 0.060 mmol) to the solution. Stir the solution at room temperature for 18 hours. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry under vacuum to give the desired compound (0.009 g, 39%). (LCMS, ESIpos.) Calculated for C 22 H 19 FN4O2: 391.4 (M+H), found: 391.2. 1 H NMR (400 MHz, chloroform-d) δ 9.12 (d, J = 1.6 Hz, 1H), 8.44 (dd, J = 1.6, 1.0 Hz, 1H), 8.04–7.97 (m, 3H), 7.97–7.88 (m, 2H), 7.67–7.59 (m, 2H), 7.43 (td, J = 8.2, 6.0 Hz, 1H), 7.16–7.05 (m, 1H), 6.60 (s, 1H), 3.69 (td, J = 5.6, 4.3 Hz, 2H), 3.63–3.55 (m, 2H), 3.40 (d, J = 0.9 Hz, 3H).

[0495] Example 55

[0496] Synthesis of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)-N-(3-hydroxypropyl)benzamide (Compound 9)

[0497]

[0498] Treat a mixture of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.02 g, 0.060 mmol) and HATU (0.025 g, 0.066 mmol) in DMF (0.200 ml) with DIPEA (0.013 ml, 0.072 mmol). Stir the solution at room temperature for 10 minutes. Add 3-aminopropan-1-ol (4.56 μl, 0.060 mmol) to the solution. Stir the solution at room temperature for 18 hours. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate, and dry in vacuo to obtain the desired compound (0.002 g, 9%). (LCMS, ESI pos.) Calculated for C 22 H 19 FN4O2: 391.4 (M+H), measured: 391.2. 1 1H NMR (400 MHz, chloroform-d) δ 9.14 (d, J = 1.6 Hz, 1H), 8.43 (t, J = 1.3 Hz, 1H), 8.04–7.97 (m, 3H), 7.97–7.89 (m, 2H), 7.68–7.59 (m, 2H), 7.43 (td, J = 8.2, 5.9 Hz, 1H), 7.15–7.06 (m, 1H), 6.96 (d, J = 10.7 Hz, 1H), 3.78 (t, J = 5.5 Hz, 2H), 3.68 (q, J = 6.0 Hz, 2H), 1.85 (p, J = 5.6 Hz, 2H).

[0499] Figure 21 The IC50 of compound 9 was shown to be 0.73 μM.

[0500] Example 56

[0501] Synthesize tert-butyl (3-(4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzamido)propyl)carbamate (Compound 12)

[0502]

[0503] Treat a mixture of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.02 g, 0.060 mmol) and HATU (0.025 g, 0.066 mmol) in DMF (0.200 ml) with DIPEA (0.013 ml, 0.072 mmol). Stir the solution at room temperature for 10 minutes. Add (3-aminopropyl)carbamic acid tert-butyl ester (10.45 mg, 0.060 mmol) to the solution. Stir the solution at room temperature for 18 hours. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry in vacuo to obtain the desired compound (0.002 g, 7%). (LCMS, ESI pos.) Calculated for C 27 H 28 FN5O3: 490.6 (M+H), measured: 490.3. 1 1H NMR (400 MHz, chloroform-d) δ 9.10 (d, J = 1.6 Hz, 1H), 8.45 (t, J = 1.3 Hz, 1H), 8.08 (d, J = 8.1 Hz, 2H), 7.97–7.90 (m, 3H), 7.68–7.61 (m, 2H), 7.51 (d, J = 12.0 Hz, 1H), 7.42 (td, J = 8.2, 6.0 Hz, 1H), 7.09 (tdd, J = 8.3, 2.5, 1.1 Hz, 1H), 4.86 (s, 1H), 3.54 (q, J = 6.1 Hz, 2H), 3.28 (q, J = 6.4 Hz, 2H), 1.74 (p, J = 6.1 Hz, 2H), 1.45 (s, 9H).

[0504] Example 57

[0505] Synthesis of N-(2-acetamidoethyl)-4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 10)

[0506]

[0507] Treat a solution of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.02 g, 0.060 mmol) and HATU (0.025 g, 0.066 mmol) in DMF (0.200 ml) with DIPEA (0.013 ml, 0.072 mmol). Stir the solution at room temperature. After 10 minutes, the solution is treated with N-(2-aminoethyl)acetamide (6.13 mg, 0.060 mmol). Stir the solution at room temperature. Filter the solution. Grind the solid with EtOAc / MeOH 1:1. Decant the solution. Dry the solid in vacuo to give the desired compound (2.4 mg, 10%). (LCMS, ESI pos.) Calculated for C 23 H 20 FN5O2: 418.4 (M+H), found: 417.8. 1 H NMR (400 MHz, chloroform-d) δ 9.19 (d, J = 1.5 Hz, 1H), 8.43–8.39 (m, 1H), 8.26 (s, 1H), 8.11–8.05 (m, 2H), 7.90 (d, J = 8.1 Hz, 2H), 7.64–7.52 (m, 3H), 7.40–7.33 (m, 1H), 7.04 (td, J = 8.4, 2.2 Hz, 1H), 3.51 (d, J = 5.7 Hz, 2H), 3.39 (d, J = 8.1 Hz, 2H), 1.96–1.91 (m, 3H).

[0508] Figure 22 The IC50 of compound 10 was shown to be 5.45 μM.

[0509] Example 58

[0510] Synthesis of N-(2-(1H-imidazol-5-yl)ethyl)-4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzamide (Compound 11)

[0511]

[0512] Treat a mixture of 4-(6-(3-fluorophenyl)imidazo[1,5-a]pyrazin-3-yl)benzoic acid (0.04 g, 0.120 mmol) and HATU (0.050 g, 0.132 mmol) in DMF (0.400 ml) with DIPEA (0.025 ml, 0.144 mmol). Stir the solution at room temperature for 10 minutes. Add 2-(1H-imidazol-5-yl)ethan-1-amine (0.013 g, 0.120 mmol) to the solution. Stir the solution at room temperature for 18 hours. Introduce the solution into a 24 g silica gel column equilibrated with EtOAc. Elute with a gradient (EtOAc to 10% MeOH / EtOAc). Combine the desired fractions, concentrate and dry under vacuum to obtain the desired compound (0.005 g, 10%). (LCMS, ESI pos.) Calculated C 24 H 19 FN6O: 427.5 (M+H), measured: 427.1. 1 H NMR (400 MHz, chloroform-d) δ 9.33 (d, J = 1.5 Hz, 1H), 8.87 (t, J = 1.3 Hz, 1H), 8.78 (t, J = 5.6 Hz, 1H), 8.52 (dd, J = 4.3, 1.4 Hz, 1H), 8.34 (dd, J = 8.4, 1.4 Hz, 1H), 8.18–8.06 (m, 4H), 8.01–7.93 (m, 1H), 7.66 (d, J = 1.3 Hz, 1H), 7.57 (td, J = 8.2, 6.2 Hz, 1H), 7.34 (dd, J = 8.4, 4.3 Hz, 1H), 7.29 (ddd, J = 10.4, 8.1, 2.6 Hz, 1H), 6.91 (s, 1H), 3.58 (td, J = 7.4, 5.5 Hz, 1H), 2.84 (t, J = 7.4 Hz, 1H).

[0513] Example 59. Enzyme Assay

[0514] The assay was performed in a 96-well black solid bottom plate with a final assay volume of 100 μL. As shown in Table 2, Compounds 1-3 showed IC50 values for activating CD206 and selectively targeting M2 macrophages.

[0515] Table 2

[0516]

[0517]

[0518] Figures 1A - 1CA graph showing the percentage of relative cell viability versus log molar concentration, illustrating the selective anti-M2 macrophage activity determined by reducing the viability of M2 macrophages with compounds 1-3 respectively.

[0519] When recombinant CD206 was incubated with compound 1, electron microscopy studies showed that compound 1 bound to CD206 and induced a conformational change of the receptor. Figure 11A and 11B Illustrated the conformational changes on CD206 when incubated with compound 1.

[0520] Similar to the activity of selectively synthesizing peptide RP-182 in M2 macrophages, the anti-M2 macrophage activity of compounds 1-3 was also CD206-dependent. Figures 2A - 2C A graph showing the percentage of relative cell viability versus log molar concentration, illustrating that the macrophage activities of compounds 1-3 were CD206-dependent respectively.

[0521] Example 60. Cell-based assay

[0522] The cell-based 2HG quantitative assay was performed in a 96-well clear plate with a final assay volume of 100 μL.

[0523] The induction of phagocytosis, autophagy and apoptosis was studied in two in vitro models using M1 and M2 macrophages. First, in the in vitro model of bone marrow-derived macrophages (BMDM), compound 1 showed excellent selectivity in inducing phagocytosis, autophagy and apoptosis in M2 macrophages, but not in M1 macrophages. Figures 12A to 12E Illustrated this selectivity. In the in vitro model of RAW264.7 cells, compound 1 also showed excellent selectivity in inducing phagocytosis, autophagy and apoptosis in M2 macrophages, but not in M1 macrophages. Figures 13A to 13C Illustrated this selectivity

[0524] Compound 1 selectively increased the phagocytosis of cancer cells in M2 macrophages, but not in M1 macrophages. Figures 14A to 14B Illustrated this selectivity for M2 macrophages. In addition, as Figure 16 shown, compound 1 showed a full dose-response in the induction of phagocytosis.

[0525] As Figure 8 shown, compared with M1-like macrophages, compound 1 was active in human CD206 高 M2 macrophages derived from healthy volunteers. Screening with a set of CD206-negative control cell lines showed that the activity of compound 1 was selective for CD206 高 M2 macrophages ( Figure 9A ). In dendritic cell DC2.4 viability (Figure 9B ) Fibroblast HTT viability ( Figure 9C ), RAW cell viability ( Figure 9D ), and KPC viability ( Figure 9E ) showed similar selectivity.

[0526] Figure 14A Relative quantitative fluorescence images were shown to indicate the selective induction of cancer cell phagocytosis in M2 macrophages induced by Compound 1, demonstrating that Compound 1 increased cancer cell phagocytosis in M2 macrophages but not in M1 macrophages.

[0527] Figure 14B Relative quantitative fluorescence images were shown to indicate the selective induction of cancer cell phagocytosis in M2 macrophages induced by Compound 28, demonstrating that Compound 28 increased cancer cell phagocytosis in M2 macrophages but not in M1 macrophages.

[0528] Figure 17 Percentage plots of the positive cell fraction of M1 markers measured by quantitative flow cytometry of murine M2 macrophages treated with vehicle, 20 μM Compound 1, and 20 μM Compound 2 for 2 hours were shown, demonstrating the induction of M1 markers in M2 macrophages.

Claims

1. Use of a therapeutic agent in the preparation of a medicament for treating cancer, said cancer being selected from pancreatic cancer, lung cancer, prostate cancer, breast cancer, liver cancer, colon cancer, kidney cancer, brain cancer, skin cancer, testicular cancer, ovarian cancer, malignant epithelial tumors, sarcomas, bladder cancer, endometrial cancer, blood cancers, thyroid cancer, and spinal cord cancer, wherein said therapeutic agent is a compound of the following formula: or a pharmaceutically acceptable salt thereof, wherein (a) X is N, a is N, b is C, c is N and d is CH, and the bond between the starred bridgehead carbon and d is a double bond; the bond between c and d is a single bond, the bond between b and c is a double bond, and the bond between a and the starred bridgehead carbon is a single bond; or (b) X is N or CH, a is N, b is C, c is N and d is N, and the bond between the starred bridgehead carbon and d is a double bond; the bond between c and d is a single bond, the bond between b and c is a double bond, and the bond between a and the starred bridgehead carbon is a single bond; or (c) X is N, a is C, b is N, c is CH and d is N, and the bond between the starred bridgehead carbon and d is a single bond; the bond between c and d is a double bond, the bond between b and c is a single bond, and the bond between a and the starred bridgehead carbon is a double bond; or (d) X is N, a is C, b is N, c is CH, d is CH, and the bond between the starred bridgehead carbon and d is a single bond; the bond between c and d is a double bond, the bond between b and c is a single bond, and the bond between a and the starred bridgehead carbon is a double bond; and R 3 is a pyridyl group, or a phenyl group optionally substituted by a halogen or a C1-C6 haloalkyl group; R 7 is -C(O)NR 5 R 6 or -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R 5 each independently selected, at each occurrence, from hydrogen, C1-C6 alkyl, C1-C6 hydroxyalkyl, C1-C6 alkoxy, unsubstituted -(C0-C6 alkyl)cycloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)heteroaryl, -C(O)C1-C6 alkyl, and -(C0-C6 alkyl)cycloalkyl substituted with one or more groups selected from: halogen, cyano, hydroxy, amino, nitro, oxo, azido, C2-C6 alkanoyl, C1-C4 alkoxy, C1-C4 alkyl, C1-C4 alkylthio, and monoaminoalkyl and diaminoalkyl in which the alkyl has 1-4 carbon atoms, and R 6 each is hydrogen or a C1-C6 alkyl group; or R 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by oxo, C1-C6 alkyl, CO2C1-C6 alkyl, -C(O)NR 8 R 9 or -C(O)C1-C6 alkyl; and R 8 and R 9 are each independently selected from hydrogen, C1-C6 alkyl, and -C(O)C1-C6 alkyl each time they appear.

2. The use according to claim 1, wherein said compound is a compound of the following formula:

3. The use according to claim 2, wherein said compound is a compound represented by at least one of compound 1 and compounds 4 to 29: or a pharmaceutically acceptable salt thereof.

4. The use according to claim 1, wherein said compound is a compound of the following formula: Wherein X is N or CH; R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R attached to the same nitrogen atom 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: oxo or C1-C6 alkyl; and R 8 is hydrogen.

5. The use according to claim 4, wherein said compound is a compound represented by at least one of compound 30 and compound 31: or a pharmaceutically acceptable salt thereof.

6. The use according to claim 1, wherein said compound is a compound of the following formula: Wherein R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R attached to the same nitrogen atom 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by oxo or C1-C6 alkyl; and R 8 is hydrogen.

7. The use according to claim 6, wherein said compound is a compound represented by compound 32: or a pharmaceutically acceptable salt thereof.

8. The use according to claim 1, wherein said compound is a compound of the following formula: Wherein R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R attached to the same nitrogen atom 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: oxo or C1-C6 alkyl; and R 8 is hydrogen.

9. The use according to claim 8, wherein said compound is a compound represented by compound 33: or a pharmaceutically acceptable salt thereof.

10. The use according to any one of claims 1 - 9, wherein said cancer is associated with CD206-positive tumor-associated macrophages.

11. The use according to any one of claims 1 - 9, wherein said cancer is selected from glioma, acute myeloid leukemia, acute myelogenous leukemia, chronic myelomonocytic leukemia, non-Hodgkin lymphoma, astrocytoma, melanoma, non-small cell lung cancer, cholangiocarcinoma, chondrosarcoma, Kaposi's sarcoma, and bronchial carcinoma.

12. The use according to any one of claims 1 - 9, wherein said medicament further comprises at least one additional therapeutic agent.

13. A compound of the following formula: or a pharmaceutically acceptable salt thereof, wherein (a) X is N, a is N, b is C, c is N and d is CH, and the bond between the starred bridgehead carbon and d is a double bond; the bond between c and d is a single bond, the bond between b and c is a double bond, and the bond between a and the starred bridgehead carbon is a single bond, and R 3 is a pyridyl group; or (b) X is N, a is N, b is C, c is N and d is N, and the bond between the starred bridgehead carbon and d is a double bond; the bond between c and d is a single bond, the bond between b and c is a double bond, and the bond between a and the starred bridgehead carbon is a single bond, and R 3 is a pyridyl group, or a phenyl group optionally substituted by a halogen or a C1-C6 haloalkyl group; or (c) X is N, a is C, b is N, c is CH and d is N, and the bond between the asterisk-marked bridgehead carbon and d is a single bond; the bond between c and d is a double bond, the bond between b and c is a single bond, the bond between a and the asterisk-marked bridgehead carbon is a double bond, and R 3 is a pyridyl group, or a phenyl group optionally substituted by a halogen or a C1-C6 haloalkyl group; or (d) X is N, a is C, b is N, c is CH, d is CH, and the bond between the starred bridgehead carbon and d is a single bond; the bond between c and d is a double bond, the bond between b and c is a single bond, the bond between a and the starred bridgehead carbon is a double bond, and R 3 is a pyridyl group, or a phenyl group optionally substituted by a halogen or a C1-C6 haloalkyl group; and R 7 is -C(O)NR 5 R 6 or -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R 5 each independently selected from hydrogen, hydroxy, C1-C6 alkyl, C1-C6 hydroxyalkyl, C1-C6 alkoxy, unsubstituted -(C0-C6 alkyl)cycloalkyl, -(C0-C6 alkyl)phenyl, -(C0-C6 alkyl)heteroaryl, -C(O)C1-C6 alkyl and -(C0-C6 alkyl)cycloalkyl substituted with one or more groups selected from: halogen, cyano, hydroxy, amino, nitro, oxo, azido, C2-C6 alkanoyl, C1-C4 alkoxy, C1-C4 alkyl, C1-C4 alkylthio and monoaminoalkyl and diaminoalkyl in which the alkyl has 1-4 carbon atoms, and R 6 each is hydrogen or a C1-C6 alkyl group; or R 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, and wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom with the following groups: oxo, C1-C6 alkyl, CO2C1-C6 alkyl, -C(O)NR 8 R 9 or -C(O)C1-C6 alkyl; and R 8 and R 9 each independently selected from hydrogen, C1-C6 alkyl, and -C(O)C1-C6 alkyl each time it appears.

14. The compound or salt according to claim 13, wherein said compound is a compound of the following formula: Wherein R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R attached to the same nitrogen atom 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: oxo or C1-C6 alkyl; and R 8 is hydrogen.

15. The compound or salt according to claim 14, wherein the compound is a compound represented by at least one of compound 30 and compound 31: or a pharmaceutically acceptable salt thereof.

16. The compound or salt according to claim 13, wherein the compound is a compound of the following formula: wherein R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R attached to the same nitrogen atom 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: oxo or C1-C6 alkyl; and R 8 is hydrogen.

17. The compound or salt according to claim 16, wherein the compound is a compound represented by compound 32: or a pharmaceutically acceptable salt thereof.

18. The compound or salt according to claim 13, wherein the compound is a compound of the following formula: wherein R 7 is -C(O)-NR 8 -(C0-C6 alkyl)NR 5 R 6 ; R attached to the same nitrogen atom 5 and R 6 together form a 4- to 7-membered monocyclic heterocycloalkyl ring, wherein the heterocycloalkyl ring contains 0, 1 or 2 additional heteroatoms selected from N, O, S, S(O) and SO2, wherein the heterocycloalkyl ring is optionally substituted at any carbon or heteroatom by: oxo or C1-C6 alkyl; and R 8 is hydrogen.

19. The compound or salt according to claim 18, wherein the compound is a compound represented by compound 33: Compound 33 or a pharmaceutically acceptable salt thereof.

20. Compound of formula IIA: or a pharmaceutically acceptable salt thereof, wherein R 10 is -(C0-C6 alkyl)phenyl; R 11 is -(C0-C6 alkyl) heteroaryl; R 12 、R 14 and R 15 are hydrogen; R 13 is -C(O) heteroaryl.

21. The compound or salt according to claim 20, wherein the compound of formula IIA is compound 2: or a pharmaceutically acceptable salt thereof.

22. Compound of formula III: or a pharmaceutically acceptable salt thereof, wherein R 17 is -C(O)C1-C6 alkyl; R 18 is a C1-C6 alkyl group; R 19 、R 20 and R 22 are hydrogen; R 21 is - NR 23 R 24 ; X is oxygen; R 23 is -CO2 phenyl; and R 24 is -SO2 phenyl.

23. The compound or salt according to claim 22, wherein the compound of formula III is compound 3: or a pharmaceutically acceptable salt thereof.

24. Use of a therapeutic agent in the manufacture of a medicament for the treatment of cancer, the cancer being characterized by selectively targeting M2 macrophages in a patient and reprogramming the M2 macrophages into an M1 phenotype, wherein the therapeutic agent is the compound or a salt thereof according to any one of claims 20 to 23.

25. The use according to claim 24, wherein CD206, a large C-type lectin receptor, targets and modulates M2 macrophages and induces cell death.

26. The use according to claim 24, wherein the cancer is selected from glioma, acute myeloid leukemia, acute myelogenous leukemia, myelodysplastic / myeloproliferative neoplasms, sarcoma, chronic myelomonocytic leukemia, non-Hodgkin lymphoma, astrocytoma, melanoma, non-small cell lung cancer, cholangiocarcinoma, chondrosarcoma, colon cancer or pancreatic cancer.

27. The use according to claim 24, further comprising administering to a patient in need at least one additional therapeutic agent.

Images