Bifunctional degraders of interleukin-1 receptor-associated kinases and therapeutic uses thereof

Abstract

This disclosure provides bifunctional compounds that act as IRAK4 degradation products via the ubiquitin-proteasome pathway, and methods for treating diseases regulated by IRAK4.

Description

[0001] This application is a divisional application of Chinese invention patent application (application date: August 18, 2022; application number: 202280056402.6 (international application number: PCT / US2022 / 040765); invention title: bifunctional degradation products of interleukin-1 receptor-related kinase and their therapeutic uses therein).

[0002] Cross-references to related applications

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 234,606, filed August 18, 2021, which is incorporated herein by reference in its entirety. Background Technology Technical Field

[0005] This invention provides novel bifunctional compounds for the proteolytic degradation of interleukin-1 receptor-associated kinase 4 (IRAK4) and methods for treating diseases regulated by IRAK4.

[0006] Related technical descriptions

[0007] Interleukin-1 receptor-associated kinase-4 (IRAK4) is a serine / threonine kinase that plays a crucial role in immune cell-mediated signaling of the toll-like receptor (TLR) and interleukin-1 receptor (IL1R), leading to the production of pro-inflammatory cytokines. IRAK4 functions as part of the myddosome, a large multiprotein complex that assembles at the plasma membrane upon ligand binding to TLR and IL1R receptors. The first step in myddosome assembly is the recruitment of the scaffold protein MyD88, to which IRAK4 then binds via homodyne death domain (DD) interaction. IRAK4 then undergoes autoactivation, subsequently phosphorylating downstream kinases IRAK1 and IRAK2. IRAK4 is considered a “major regulator” of myddosome signaling because it is the most upstream kinase in the complex. The importance of IRAK4 kinase function has been demonstrated in IRAK-4 kinase-dead mice, which are resistant to TLR-induced septic shock due to their inability to produce pro-inflammatory cytokines.

[0008] IRAK4 has also been reported to possess kinase-independent scaffolding function. For example, macrophages from mice with dead IRAK4 kinases were still able to activate NF-κB signaling upon stimulation with IL1, TLR2, TLR4, and TLR7. Similar scaffolding function has been demonstrated in human fibroblasts, where kinase-dead IRAK4 was able to restore IL-1-induced NF-κB signaling to levels comparable to WT IRAK4.

[0009] Therefore, IRAK4 can be targeted for degradation, thus offering therapeutic opportunities in the treatment of autoimmune diseases, inflammatory diseases, and oncological diseases. Specific degradation of IRAK4 can be achieved by using heterobifunctional small molecules to recruit IRAK4 to ubiquitin ligases, thereby promoting IRAK4 ubiquitination and proteasome degradation. For example, thalidomide derivatives (such as lenalidomide or pomalidomide) have been reported to recruit potential protein substrates to cereblon (CRBN) (a component of the ubiquitin ligase complex). See, for example, WO 2019 / 099926, WO 2020 / 023851, PCT / US2021 / 018710 (NU-1700 PCT, 401WO) and U.S. Publication 2019 / 0192668.

[0010] Further development of therapeutic agents targeting IRAK4 is needed. Summary of the Invention

[0011] This disclosure provides a bifunctional compound represented by formula (I):

[0012]

[0013] Formula (I)

[0014] Or its pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers, wherein:

[0015] R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; or optionally marked with 1-3 R a Substituted 4-12 membered heterocyclic groups; or optionally replaced by 1-3 R groups. a Substituted 5-12 heteroaryl groups;

[0016] L is -L1-L2-L3-L4-, and each L1, L2, L3, and L4 is independently:

[0017] a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl;

[0018] b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl;

[0019] c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups;

[0020] d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups;

[0021] e) Direct key;

[0022] f) Randomly selected by 1-3 R d Replacement C 1-12 Alkylene chain;

[0023] g) Randomly selected by 1-3 R d Replacement C 2-12 Alkenyl chain;

[0024] h) can be arbitrarily assigned to 1 to 3 R d Replacement C 2-12 Alkyne chain;

[0025] i) 1-6 ethylene glycol units;

[0026] j) 1-6 propylene glycol units; or

[0027] k)-C(O)-, -C(O)O-, -O-, -N(R c )-, -S-, -C(S)-, -C(S)-O-, -S(O)2-, -S(O)=N-, -S(O)2NH-, -C(O)-N(R c -, -C=N-, -OC(O)-N(R) c )-or-OC(O)-O-;

[0028] Each R a Independently a halogenated group, -CN, optionally enclosed by 1 to 3 R groups d Replacement C 1-3 Alkyl groups, optionally with 1 to 3 R groups d Replacement C 3-6 cycloalkyl, or -OR c ;

[0029] Each R b Independently, it can be an oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR c -C(O)-R c-C(O)OR c -C(O)-N(R) c (R) c ), -N(R c (R) c ), -N(R c )C(O)-R c -N(R) c )C(O)OR c -N(R) c )C(O)N(R c (R) c ), -N(R c )S(O)2(R c -NR c S(O)2N(R c (R) c ), -N(R c )S(O)2O(R c -OC(O)R c -OC(O)-N(R) c (R) c ), -Si(R c )3、-SR c -S(O)R c -S(O)(NH)R c -S(O)2R c or -S(O)2N(R c (R) c ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. d replace;

[0030] Each R c Independently hydrogen or C 1-6 alkyl;

[0031] Each R d Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl;

[0032] W is -C(R) g - or -N-;

[0033] Ring B is C 6-12 aryl, 5-12-membered heteroaryl, or 4-12-membered heterocyclic, each optionally bound by 1 to 3 R groups. j replace;

[0034] Each R j Independently, it can be hydrogen, oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR g -C(O)-R g -C(O)OR g -C(O)-N(R) g (R) g ), -N(R g (R) g ), -N(R g )C(O)-R g -N(R) g )C(O)OR g -N(R) g )C(O)N(R g (R) g ), -N(R g )S(O)2(R g -NR g S(O)2N(R g (R) g ), -N(R g )S(O)2O(R g -OC(O)R g -OC(O)-N(R) g (R) g ), -Si(R g )3、-SR g -S(O)R g -S(O)(NH)R g -S(O)2R g or -S(O)2N(R g (R) g ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. k replace;

[0035] R g Is it hydrogen or C? 1-6 Alkyl; and

[0036] Each R k Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl.

[0037] This article also provides bifunctional compounds represented by formula (I):

[0038]

[0039] Formula (I)

[0040] Or its pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers, wherein:

[0041] R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; or optionally marked with 1-3 R a Substituted 4-12 membered heterocyclic groups;

[0042] L is -L1-L2-L3-L4-, and each L1, L2, L3, and L4 is independently:

[0043] a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl;

[0044] b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl;

[0045] c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups;

[0046] d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups;

[0047] e) Direct key;

[0048] f) Randomly selected by 1-3 Rd Replacement C 1-12 Alkylene chain;

[0049] g) Randomly selected by 1-3 R d Replacement C 2-12 Alkenyl chain;

[0050] h) can be arbitrarily assigned to 1 to 3 R d Replacement C 2-12 Alkyne chain;

[0051] i) 1-6 ethylene glycol units;

[0052] j) 1-6 propylene glycol units; or

[0053] k)-C(O)-, -C(O)O-, -O-, -N(R c )-, -S-, -C(S)-, -C(S)-O-, -S(O)2-, -S(O)=N-, -S(O)2NH-, -C(O)-N(R c -, -C=N-, -OC(O)-N(R) c )-or-OC(O)-O-;

[0054] Each R a Independently a halogenated group, -CN, optionally enclosed by 1 to 3 R groups d Replacement C 1-3 Alkyl groups, optionally with 1 to 3 R groups d Replacement C 3-6 cycloalkyl, or -OR c ;

[0055] Each R b Independently, it can be an oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR c -C(O)-R c -C(O)OR c -C(O)-N(R) c (R) c ), -N(R c (R) c ), -N(R c )C(O)-R c -N(R) c )C(O)OR c-N(R) c )C(O)N(R c (R) c ), -N(R c )S(O)2(R c -NR c S(O)2N(R c (R) c ), -N(R c )S(O)2O(R c -OC(O)R c -OC(O)-N(R) c (R) c ), -Si(R c )3、-SR c -S(O)R c -S(O)(NH)R c -S(O)2R c or -S(O)2N(R c (R) c ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. d replace;

[0056] Each R c Independently hydrogen or C 1-6 alkyl;

[0057] Each R d Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl;

[0058] W is -C(R) g - or -N-;

[0059] Ring B is C 6-12 aryl, 5-12-membered heteroaryl, or 4-12-membered heterocyclic, each optionally bound by 1 to 3 R groups. j replace;

[0060] Each R j Independently, it can be hydrogen, oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR g -C(O)-R g -C(O)OR g -C(O)-N(R) g (R) g ), -N(R g (R) g ), -N(R g )C(O)-R g -N(R) g )C(O)OR g -N(R) g )C(O)N(R g (R) g ), -N(R g )S(O)2(R g -NR g S(O)2N(R g (R) g ), -N(R g )S(O)2O(R g -OC(O)R g -OC(O)-N(R) g (R) g ), -Si(R g )3、-SR g -S(O)R g -S(O)(NH)R g -S(O)2R g or -S(O)2N(R g (R) g ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. k replace;

[0061] R g Is it hydrogen or C? 1-6 Alkyl; and

[0062] Each R kIndependently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl.

[0063] Specifically, Part of it is the ligase utilization part (LHM) that specifically targets the CRBN ligase, which is utilized by a bifunctional compound to induce the ubiquitination of IRAK4 and subsequent proteasome degradation.

[0064] In a more specific implementation, the B-ring of the LHM has one of the following structures:

[0065] , , , , or In a more specific embodiment, the bifunctional compound is that described in Examples 1 to 147.

[0066] Another embodiment provides a pharmaceutical composition comprising a compound of formula (I) or any substructure thereof, and a pharmaceutically acceptable carrier.

[0067] In some embodiments, the compound of formula (I) or a pharmaceutical composition thereof may be used as a therapeutic agent for treating cancers such as lymphoma, leukemia, acute myeloid leukemia (AML), and myelodysplastic syndrome (MDS).

[0068] In other embodiments, the compound of formula (I) or a pharmaceutical composition thereof may be used as a therapeutic agent for treating metabolic disorders such as diabetes (type I and type II diabetes), metabolic syndrome, dyslipidemia, obesity, impaired glucose tolerance, hypertension, elevated serum cholesterol, and elevated triglycerides.

[0069] In other embodiments, the compound of formula (I) or a pharmaceutical composition thereof may be used as a therapeutic agent for treating inflammatory conditions such as rheumatoid arthritis (RA), inflammatory bowel disease (IBD), Crohn's disease, ulcerative colitis, necrotizing enterocolitis, gout, Lyme disease, arthritis, psoriasis, pelvic inflammatory disease, systemic lupus erythematosus (SLE), Sjögren's syndrome, inflammation associated with gastrointestinal infections including Clostridium difficile, viral myocarditis, acute and chronic tissue damage, non-alcoholic steatohepatitis (NASH), alcoholic hepatitis, and nephropathy, including chronic kidney disease and diabetic nephropathy. Detailed Implementation

[0070] Bifunctional compounds capable of recruiting IRAK4 to E3 ubiquitin ligases for degradation are disclosed, along with their preparation methods and uses. Specifically, the bifunctional compounds typically comprise an IRAK4 conjugate that is partially covalently conjugated to a ligase for targeting ubiquitin ligases via a linker. Advantageously, the targeted degradation of IRAK4 provides effective treatment or improvement of disease symptoms involving IRAK4 function.

[0071] Therefore, this paper presents a bifunctional compound represented by formula (I).

[0072]

[0073] Formula (I)

[0074] Or its pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers, wherein:

[0075] R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; or optionally marked with 1-3 R a Substituted 4-12 membered heterocyclic groups; or optionally replaced by 1-3 R groups. a Substituted 5-12 heteroaryl groups;

[0076] L is -L1-L2-L3-L4-, and each L1, L2, L3, and L4 is independently:

[0077] a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl;

[0078] b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl;

[0079] c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups;

[0080] d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups;

[0081] e) Direct key;

[0082] f) Randomly selected by 1-3 R d Replacement C 1-12 Alkylene chain;

[0083] g) Randomly selected by 1-3 R d Replacement C 2-12 Alkenyl chain;

[0084] h) can be arbitrarily assigned to 1 to 3 R d Replacement C 2-12 Alkyne chain;

[0085] i) 1-6 ethylene glycol units;

[0086] j) 1-6 propylene glycol units; or

[0087] k)-C(O)-, -C(O)O-, -O-, -N(R c )-, -S-, -C(S)-, -C(S)-O-, -S(O)2-, -S(O)=N-, -S(O)2NH-, -C(O)-N(R c -, -C=N-, -OC(O)-N(R) c )-or-OC(O)-O-;

[0088] Each R a Independently a halogenated group, -CN, optionally enclosed by 1 to 3 R groups d Replacement C 1-3 Alkyl groups, optionally with 1 to 3 R groups d Replacement C 3-6 cycloalkyl, or -OR c ;

[0089] Each R b Independently, it can be an oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR c -C(O)-R c -C(O)OR c -C(O)-N(R) c (R) c ), -N(R c (R) c ), -N(R c )C(O)-R c -N(R) c )C(O)OR c -N(R) c )C(O)N(R c (R) c), -N(R c )S(O)2(R c -NR c S(O)2N(R c (R) c ), -N(R c )S(O)2O(R c -OC(O)R c -OC(O)-N(R) c (R) c ), -Si(R c )3、-SR c -S(O)R c -S(O)(NH)R c -S(O)2R c or -S(O)2N(R c (R) c ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. d replace;

[0090] Each R c Independently hydrogen or C 1-6 alkyl;

[0091] Each R d Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl;

[0092] W is -C(R) g - or -N-;

[0093] Ring B is C 6-12 aryl, 5-12-membered heteroaryl, or 4-12-membered heterocyclic, each optionally bound by 1 to 3 R groups. j replace;

[0094] Each R j Independently, it can be hydrogen, oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR g -C(O)-R g -C(O)OR g -C(O)-N(R) g (R) g ), -N(R g (R) g ), -N(R g )C(O)-R g -N(R) g )C(O)OR g -N(R) g )C(O)N(R g (R) g ), -N(R g )S(O)2(R g -NR g S(O)2N(R g (R) g ), -N(R g )S(O)2O(R g -OC(O)R g -OC(O)-N(R) g (R) g ), -Si(R g )3、-SR g -S(O)R g -S(O)(NH)R g -S(O)2R g or -S(O)2N(R g (R) g ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. k replace;

[0095] R g Is it hydrogen or C? 1-6 Alkyl; and

[0096] Each R k Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl.

[0097] One specific implementation provides a bifunctional compound of formula (I):

[0098]

[0099] Formula (I)

[0100] Or its pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers, wherein:

[0101] R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; or optionally marked with 1-3 R a Substituted 4-12 membered heterocyclic groups;

[0102] L is -L1-L2-L3-L4-, and each L1, L2, L3, and L4 is independently:

[0103] a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl;

[0104] b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl;

[0105] c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups;

[0106] d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups;

[0107] e) Direct key;

[0108] f) Randomly selected by 1-3 R d Replacement C 1-12 Alkylene chain;

[0109] g) Randomly selected by 1-3 R d Replacement C 2-12 Alkenyl chain;

[0110] h) Randomly selected by 1-3 R d Replacement C 2-12 Alkyne chain;

[0111] i) 1-6 ethylene glycol units;

[0112] j) 1-6 propylene glycol units; or

[0113] k)-C(O)-, -C(O)O-, -O-, -N(R c )-, -S-, -C(S)-, -C(S)-O-, -S(O)2-, -S(O)=N-, -S(O)2NH-, -C(O)-N(R c -, -C=N-, -OC(O)-N(R) c )-or-OC(O)-O-;

[0114] Each R a Independently a halogenated group, -CN, optionally enclosed by 1 to 3 R groups d Replacement C 1-3 Alkyl groups, optionally with 1 to 3 R groups d Replacement C 3-6 cycloalkyl, or -OR c ;

[0115] Each R b Independently, it can be an oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR c -C(O)-R c -C(O)OR c -C(O)-N(R) c (R) c ), -N(R c (R) c ), -N(R c )C(O)-R c -N(R) c )C(O)OR c -N(R) c )C(O)N(R c (R) c ), -N(R c )S(O)2(R c -NR c S(O)2N(R c (R) c ), -N(R c )S(O)2O(R c -OC(O)R c-OC(O)-N(R) c (R) c ), -Si(R c )3、-SR c -S(O)R c -S(O)(NH)R c -S(O)2R c or -S(O)2N(R c (R) c ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. d replace;

[0116] Each R c Independently hydrogen or C 1-6 alkyl;

[0117] Each R d Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl;

[0118] W is -C(R) g - or -N-;

[0119] Ring B is C 6-12 aryl, 5-12-membered heteroaryl, or 4-12-membered heterocyclic, each optionally bound by 1 to 3 R groups. j replace;

[0120] Each R j Independently, it can be hydrogen, oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR g -C(O)-R g -C(O)OR g -C(O)-N(R) g (R) g ), -N(Rg (R) g ), -N(R g )C(O)-R g -N(R) g )C(O)OR g -N(R) g )C(O)N(R g (R) g ), -N(R g )S(O)2(R g -NR g S(O)2N(R g (R) g ), -N(R g )S(O)2O(R g -OC(O)R g -OC(O)-N(R) g (R) g ), -Si(R g )3、-SR g -S(O)R g -S(O)(NH)R g -S(O)2R g or -S(O)2N(R g (R) g ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. k replace;

[0121] R g Is it hydrogen or C? 1-6 Alkyl; and

[0122] Each R k Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl.

[0123] IRAK4 complex

[0124] The IRAK4 conjugate portion of the bifunctional compound of formula (I) has the following structure, wherein the wavy lines show the bonds that connect to the rest of the compound of formula (I).

[0125]

[0126] Where R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; optionally marked with 1-3 R a The substituted 4-12 membered heterocyclic group, or optionally replaced by 1-3 R groups. a Substituted 5-12 heteroaryl groups.

[0127] In a more specific implementation plan, R 1 yes:

[0128] a) Optionally selected by one to three independent free radicals, -OH, -OC 1-4 The C-substituents of the group consisting of alkyl and -CN 1-5 alkyl;

[0129] b) Optionally selected by one to three independent free halogen groups, C 1-5 Alkyl, -OH, -OC 1-4 Substituents of alkyl groups and -CN groups are 4-8 membered heterocyclic groups that are substituted.

[0130] c) Optionally selected by one to three independent free halogen groups, C 1-5 Alkyl, -OH, -OC 1-4 The C-substituents of the group consisting of alkyl and -CN 3-10 cycloalkyl;

[0131] d) Optionally selected by one to three independent free halogenated groups, C 1-5 Alkyl, -OH, -OC 1-4 5-6 membered heteroaryl groups consisting of alkyl groups and -CN groups.

[0132] In even more specific implementation plans, R 1 yes:

[0133] a) C groups optionally substituted with a halogenated group, -OH, or -CN 1-5 alkyl;

[0134] b) Optional halogenated groups, C 1-5 Alkyl, -OH, or -CN substituted 4-8 membered heterocyclic groups; or

[0135] c) Optionally coated with halogenated groups, C 1-5 C substituted with alkyl, -OH or -CN 3-10 Cycloalkyl.

[0136] In a more specific implementation plan, R 1 It is an oxetane, tetrahydrofuran, or tetrahydropyran, each of which can be optionally converted by F or C. 1-3 Alkyl, -OH or -CN substitution.

[0137] In some implementation schemes, R 1 It is cyclobutyl, cyclohexyl, cyclopropyl, isoxazolyl, or C 1-4 Alkyl groups, each optionally selected independently from one to three F and C atoms. 1-3 Substituents in the group consisting of alkyl, -OH, -OCH3 or -CN.

[0138] In other, more specific implementation schemes,

[0139] The portion has one of the following structures (the wavy lines show the bonds connected to the thiadiazole portion):

[0140]

[0141]

[0142]

[0143] In another implementation scheme,

[0144] The portion has one of the following structures (the wavy lines show the bonds connected to the thiadiazole portion):

[0145] , , , , , , , , or

[0146] .

[0147] Targeting hydroxycerebroside ligase utilization moiety (LHM)

[0148] CRBN proteins are substrate recognition subunits of two widely expressed and biologically significant CullinRING E3 ubiquitin ligase complexes. The LHM of the compound of formula (I) targets the CRBN of the E3 ligase, which is utilized by the bifunctional compound to induce the ubiquitination of IRAK4 and subsequent proteasome degradation.

[0149] One embodiment provides a CRBN targeting LHM having the following structure (waveform lines show the bonds connected to the remainder of the compound of formula (I)):

[0150]

[0151] Equation (II)

[0152] in,

[0153] W is -C(R) g )- or -N-,

[0154] Ring B is C 6-12 aryl, 5-12-membered heteroaryl, or 4-12-membered heterocyclic, each optionally bound by 1 to 3 R groups. j replace;

[0155] Each R j Independently, it can be hydrogen, oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR g -C(O)-R g -C(O)OR g -C(O)-N(R) g (R) g ), -N(R g (R) g ), -N(R g )C(O)-R g -N(R) g )C(O)OR g -N(R) g )C(O)N(R g (R) g ), -N(R g )S(O)2(R g -NR g S(O)2N(R g (R) g ), -N(R g )S(O)2O(R g -OC(O)R g -OC(O)-N(R) g (R) g ), -Si(R g )3、-SR g-S(O)R g -S(O)(NH)R g -S(O)2R g or -S(O)2N(R g (R) g ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. k replace;

[0156] R g Is it hydrogen or C? 1-6 Alkyl; and

[0157] Each R k Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl.

[0158] In some specific implementations, ring B has one of the following structures:

[0159] , , , , or .

[0160] In a preferred embodiment, W is -CH-.

[0161] In a more specific implementation, W is -CH- and CRBN-targeting LHM has one of the following structures:

[0162] , , , or .

[0163] In a more specific implementation plan, R j It is hydrogen or a halogroup (e.g., fluorine).

[0164] In other implementations, W is -N-.

[0165] In a more specific implementation, W is -N- and CRBN-targeted LHM has the following structure:

[0166] .

[0167] In a more specific implementation, W is -N-, and the CRBN-targeted LHM has the following structure:

[0168] , or .

[0169] connector

[0170] The bifunctional compound of formula (I) includes a linker portion that couples the IRAK4 conjugate to the LHM. The structure of the linker portion (e.g., length or stiffness) can affect the efficiency or selectivity of the degradation process. Typically, the linker portion comprises multiple segments that, in addition to providing corresponding connection points with the IRAK4 conjugate and the LHM, also contribute to the overall length and stiffness of the linker.

[0171] In some embodiments, the connector portion (L) of formula (I) has up to four connector segments (L) s (where s is 1, 2, 3, or 4) and each L1, L2, L3, and L4 is independently a divalent part selected from the following:

[0172] a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl;

[0173] b) Randomly selected by 1-3 R b Substituted aryl groups;

[0174] c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups;

[0175] d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups;

[0176] e) Direct key;

[0177] f) Randomly selected by 1-3 R d Replacement C 1-12 Alkylene chain;

[0178] g) Randomly selected by 1-3 R d Replacement C 2-12 Alkenyl chain;

[0179] h) can be arbitrarily assigned to 1 to 3 R d Replacement C 2-12 Alkyne chain;

[0180] i) 1-6 ethylene glycol units;

[0181] j) 1-6 propylene glycol units; and

[0182] k)-C(O)-, -C(O)O-, -O-, -N(R c )-, -S-, -C(S)-, -C(S)-O-, -S(O)2-, -S(O)=N-, -S(O)2NH-, -C(O)-N(R c -, -C=N-, -OC(O)-N(R) c )-or-OC(O)-O-;

[0183] Each R b Independently, it can be an oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR c -C(O)-R c -C(O)OR c -C(O)-N(R) c (R) c ), -N(R c (R) c ), -N(R c )C(O)-R c -N(R) c )C(O)OR c -N(R) c )C(O)N(R c (R) c ), -N(R c )S(O)2(R c -NR c S(O)2N(R c (R) c ), -N(R c )S(O)2O(R c -OC(O)R c -OC(O)-N(R) c (R) c ), -Si(R c )3、-SR c -S(O)R c -S(O)(NH)R c -S(O)2R cor -S(O)2N(R c (R) c ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. d replace;

[0184] Each R c Independently hydrogen or C 1-6 Alkyl; and

[0185] Each R d Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl groups, or C groups optionally substituted with 1 to 3 fluorine atoms. 3-8 cycloalkyl;

[0186] In a more specific implementation, each L1, L2, L3, and L4 is independently:

[0187] a) Randomly selected by 1-3 R b Replacement C 4-12 cycloalkyl;

[0188] b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl;

[0189] c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups;

[0190] d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups;

[0191] e) Direct key;

[0192] f) Optionally divided by 1-3 R d Replacement C 1-12 alkylene chains; or

[0193] g)-C(O)-、-O-、-N(R c - or -C(O)-N(R) c )-.

[0194] It should be understood that, unless otherwise specified and conditional upon satisfying valence, the divalent portion (e.g., L or L) described herein is... s(This is not limited to the directions they represent.) For example, for a given linker segment, such as -C(O)-NH-, it can be connected to the rest of the molecule in either direction: either -C(O)-NH- or -NH-C(O)-, provided that the connection does not violate the valence rule.

[0195] On the other hand, when L is composed of a series of L s When representing, it can be done through a specific L s The orientation of the positions is established in a manner consistent with the structure of Equation (I). For example, joint segment L1 should be understood as being directly coupled to the IRAK4 conjugate portion; while joint segment L4 should be understood as being directly coupled to LHM.

[0196] One or more connector segments can be direct keys. For example, in -L2-L3-L4--, when L3 is a direct key, it does not actually exist because L2 and L4 are directly connected to each other.

[0197] In various specific implementation schemes, L1 is selected from C. 3-12 Cycloalkyl rings; 6-15-membered aryl, 3-15-membered heterocyclic and 5-15-membered heteroaryl, each of which may be further divided by up to 3 Rs. d (As defined herein) Replacement. In a more specific implementation, L1 is selected from C 4-12 Cycloalkyl rings; 6-12-membered aryl, 4-12-membered heterocyclic and 5-12-membered heteroaryl, each of which may be further divided by up to 3 Rs. d (As defined in this article) Replace.

[0198] In various specific implementation schemes, L1 can be one of the following ring portions:

[0199] , , , , , , or .

[0200] In other specific implementations, L1 can be or .

[0201] In specific implementations, -L2-L3-L4- has one of the following structures:

[0202] -C(O)-, -(CH2) m -、 , , , , , , , , , , , , , , , , , , or ,

[0203] Where m is 1, 2, or 3, and R c Is it H or C? 1-3 alkyl.

[0204] In a further specific implementation, -L2-L3-L4- has one of the following structures:

[0205] , , , , , , , , , , or .

[0206] In a more specific implementation, L has one of the following structures:

[0207] , , , , , , , , , , , , , , , , , , , , , , , , , or ,

[0208] Where R c Is it H or C? 1-3 Alkyl group, and m is 1, 2 or 3.

[0209] In other, more specific implementations, L has one of the following structures:

[0210] , , , , , , , , , , , , , , , , , , , , , , or .

[0211] Construction of compounds of formula (I)

[0212] The synthesis or construction of compounds of formula (I) can be carried out in multiple steps, typically involving the separate preparation of structural units of the IRAK4 conjugate and the LHM moiety, followed by the formation of covalent bonds connecting the respective structural units. Generally, any one or two structural units can be generated using one or more linker precursors (L... x The precursor is prepared using one or more connector segments (L...). s It also has terminal reactive groups for further coupling. The two structural units can ultimately be coupled (via L...) s (Formulation of fragments) to obtain the compound of formula (I).

[0213] The following schemes demonstrate a general method for preparing structural units. Examples 1 to 147 are specific examples of formula (I), which are synthesized and characterized by their respective physiological and chemical properties.

[0214] A. Preparation of IRAK4 conjugate structural units

[0215] This article describes many general schemes for preparing IRAK4 conjugate structural units.

[0216] Option A1

[0217]

[0218] The compound of Formula 1.5 can be obtained according to the method outlined in Scheme 1. Using a suitable catalyst (e.g., HCl, etc.) and a suitable solvent (e.g., EtOH, etc.), 1-aminopyrrole 1.1 can be condensed with a suitable coupling partner to produce a substituted pyrrolo[1,2-b]pyridazine 1.2. Halogenation at the indicated positions using a known halogenating agent (e.g., NBS, etc.) can form intermediate 1.3, which can be further substituted by CH activation or electrophilic aromatic substitution with a suitable agent (e.g., a fluorine agent (selectfluor, etc.) to produce intermediate 1.4. Halogen metal exchange from -X to -M can then be achieved using a suitable agent (e.g., n-BuLi, etc.), or transition metal coupling can be achieved using a palladium catalyst and a metal source (e.g., B2Pin2, Me6Sn2, etc.) to obtain intermediate 1.5.

[0219] Option A2

[0220]

[0221] Compounds of Formula 2.3 can be obtained according to the methods outlined in Scheme 2. Acid 2.1 can be converted to the corresponding acylhydrazine in the presence of a base (e.g., DIPEA, etc.) using a coupling agent (e.g., HATU, etc.). Cyclization of compound 2.2 can be accomplished by heating in the presence of a sulfiding agent (e.g., Lawson's reagent, etc.) to provide compound 2.3.

[0222] Option A3

[0223]

[0224] Compounds of Formula 3.6 can be obtained according to the methods outlined in Scheme 3. Dihalopyridine 3.1 can be converted to compound 3.2 by substituting a halogen group (e.g., nucleophilic aromatic substitution, etc.). Further functionalization of compound 3.2 using a metal-containing heterocyclic compound (e.g., compound 1.5) with a suitable catalyst such as a palladium catalyst yields compound 3.3. Halogenation at the indicated position using a known halogenating agent (e.g., NBS, etc.) forms intermediate 3.4, which can be further substituted via a cross-coupling reaction using a suitable catalyst such as a palladium catalyst to provide compound 3.5.

[0225] Option A4

[0226]

[0227] The compound of formula 4.2 can be assembled according to scheme A4. Replacing the halogen group of halothiadiazole 4.1 with a nucleophilic reagent (e.g., amine, etc.) (e.g., nucleophilic aromatic substitution, etc.) can provide compound 2.3. Halogenation at the indicated position using a known halogenating agent (e.g., NBS, etc.) can form intermediate 4.2.

[0228] Solution A5

[0229]

[0230] Compound 3.5 can also be assembled according to scheme A5. Then, halogen metal exchange from -X to -M can be achieved using suitable reagents (e.g., n-BuLi, etc.), or transition metal coupling can be achieved using a palladium catalyst and a metal source (e.g., B2Pin2, Me6Sn2, etc.) to obtain intermediate 5.1. Functionalization of compound 5.1 can be carried out using a suitable catalyst, such as a palladium catalyst, via a cross-coupling reaction with compound 4.2 to provide compound 3.5.

[0231] According to scheme A5, L x It can be a ring with a reactive portion, which can be coupled to another joint segment. For example, the L protected by BOC. x It could be:

[0232] ; and compound 4.2 is The resulting compound 3.5 is an IRAK4 conjugate structural unit with an L1 precursor (i.e., a piperazine ring), which can be further coupled to another linker fragment via a reactive secondary amine of piperazine.

[0233] Option A6

[0234]

[0235] An alternative method for obtaining compound 3.5 is shown in scheme A6. Starting with nicotinic acid 6.1, the corresponding acylhydrazine can be prepared in the presence of a base (e.g., DIPEA, etc.) using a coupling agent (e.g., HATU, etc.). Cyclolation of compound 6.3 can be accomplished by heating in the presence of a sulfiding agent (e.g., Lawson's reagent, etc.) to provide compound 6.4. Further functionalization of compound 6.4 using a metal-containing heterocyclic substance (e.g., compound 1.5) and a suitable catalyst such as a palladium catalyst yields compound 3.5.

[0236] According to scheme A6, L xIt can be a ring with a reactive portion, which can then be coupled to another linker segment. For example, L x It could be:

[0237] (Optionally protected by BOC during synthesis) and the resulting compound 3.5 is another IRAK4 conjugate structural unit with an L1 precursor (i.e., a bicyclic [2.2.2]octane ring), which can be further coupled to another linker fragment via a reactive primary amine.

[0238] The following section provides a more detailed example of the preparation of an IRAK4 conjugate structural unit, which is an intermediate to be further coupled with LHM.

[0239] Intermediate A: 7-(5-(5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl)-4-((tetrahydro-2H-pyran-4-yl)) (amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile .

[0240]

[0241] Step 1: DIEA (33.1 g, 255 mmol, 44.5 mL, 1.50 equivalent) and tetrahydro-2H-pyran-4-amine (20.7 g, 204 mmol, 1.20 equivalent) were added to a solution of 2-bromo-4-fluoropyridine (30.0 g, 170 mmol, 1.00 equivalent) in NMP (300 mL), and the mixture was stirred at 110 °C for 1.5 h. The reaction mixture was poured into H2O (500 mL) and extracted with methyl tert-butyl ether (500 mL × 4). The combined organic layers were washed with saturated brine (500 mL × 6) and dried over anhydrous Na2SO4, filtered, and concentrated under vacuum to give 2-bromo-N-(tetrahydro-2H-pyran-4-yl)pyridin-4-amine. The residue was used in the next step without further purification (46 g). LCMS: m / z = 257.2 (M+H) +

[0242] Step 2: Under N2, add K3PO4 (2.00 M, 102 mL, 2.00 equivalent) and Pd(dppf)Cl2 to a DME (300 mL) solution of the product from Step 1 (30.0 g, 101 mmol, 1.00 equivalent) and 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (35.5 g, 132 mmol, 1.30 equivalent). CH2Cl2 (8.29 g, 10.2 mmol, 0.100 equivalents) was used to stir the mixture at 100 °C for 2 hours under N2. The reaction mixture was concentrated under reduced pressure to give a residue, which was then analyzed by MPLC (SiO2, petroleum ether / ethyl acetate = 10 / 1 to 0 / 1, R...). f = 0.10) Purification. 7-(4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (30.0 g, 93.5 mmol, 92.1% yield) was given as a yellow solid. LCMS: m / z = 320.2 (M+H) +

[0243] Step 3: At 0°C, a solution of NBS (16.7 g, 93.6 mmol, 0.880 equivalent) in MeCN (127 mL) and DCM (758 mL) was added to a solution of 7-(4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (36.0 g, 106 mmol, 1.00 equivalent) in MeCN (758 mL) and DCM (758 mL). The mixture was stirred at 0°C for 0.5 h. The reaction mixture was filtered, the filter cake was collected, and the filtrate was concentrated under reduced pressure to obtain the residue. The residue was subjected to MPLC (SiO2, petroleum ether / ethyl acetate = 10 / 1 to 1 / 1, R... f = 0.60) Purification. The filter cake and the MPLC residue of the yellow solid were combined to give 7-(5-bromo-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (34.9 g, 85.8 mmol, 80.6% yield). LCMS: m / z = 397.9 (M+H) +

[0244] Step 4: Under N2, add KOAc (25.2 g, 257 mmol, 3.00 equivalent) and Pd(PPh3)2Cl2 (9.02 g, 12.9 mmol, 0.150 equivalent) to a solution of 7-(5-bromo-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (34.9 g, 85.7 mmol, 1.00 equivalent) and 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bis(1,3,2-dioxane) (43.5 g, 171 mmol, 2.00 equivalent) in DMF (175 mL) and dioxane (350 mL), and stir the mixture under N2 at 120 °C for 3 hours. The reaction mixture was filtered through silica gel, and the filtrate was concentrated under reduced pressure to obtain the residue. The crude product was purified by reversed-phase HPLC (TFA conditions). The desired product was given as a yellow solid (13.3 g, 25.5 mmol, 29.8% yield, TFA). LCMS: Product: m / z = 364.0 (M+H) +

[0245] Step 5: DIEA (21.2 g, 164 mmol, 28.5 mL, 2.00 equivalent) was added to a solution of 2,5-dibromo-1,3,4-thiadiazole (20.0 g, 82.0 mmol, 1.00 equivalent) and piperazine-1-carboxylate tert-butyl ester (18.3 g, 98.4 mmol, 1.20 equivalent) in dioxane (200 mL). The mixture was then stirred at 110 °C for 2 hours. The mixture was cooled to 25 °C and filtered. The filter cake was washed with ethyl acetate (50.0 mL × 2), and the filtrate was washed with brine (200 mL × 2). The solution was dried over anhydrous Na₂SO₄, filtered, and concentrated under reduced pressure to obtain the residue. The residue was used in the next step without further purification. 4-(5-bromo-1,3,4-thiadiazole-2-yl)piperazine-1-carboxylate tert-butyl ester (31.8 g, crude) was given as a red solid. LCMS: m / z = 294.8(M+H) +

[0246] Step 6: Under N2, add Pd(OAc)2 (518 mg, 2.3 mmol, 0.200 equivalent), Xantphos (2.67 g, 4.6 mmol, 0.400 equivalent), and Cs2CO3 (9.39 g, 28.8 mmol, 2.50 equivalent) to a solution of (6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-3-yl)boronic acid (6.00 g, 11.5 mmol, 1.00 equivalent, TFA) and 4-(5-bromo-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (4.23 g, 12.1 mmol, 1.05 equivalent) in dioxane (315 mL). Stir the mixture under N2 at 120 °C for 5 hours. Filter the reaction mixture; wash the filter cake with ethyl acetate (200 mL × 3) and collect. Filter the filtrate, collect the filter cake, and wash the filtrate with water (500 mL × 2), dry to Na₂SO₄, filter and concentrate under reduced pressure to give tert-butyl 4-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylate (6.00 g, 8.7 mmol, 75% yield) as a yellow solid. This yellow solid was used in the next step without further purification. [Expected...]

[0247] Step 7: A mixture of tert-butyl piperazine-1-carboxylate (6.00 g, 8.7 mmol, 1.00 equivalent) in HCl / EtOAc (4.00 M, 52.4 mL, 24.2 equivalent) and EtOAc (20.0 mL) was stirred at 25 °C for 2.5 h. The reaction mixture was filtered, and the resulting filter cake was collected and concentrated under reduced pressure to give the title product hydrochloride as a yellow solid (4.06 g, 7.2 mmol, 82.6% yield). LCMS: m / z = 488.4 (M+H) + . 1 H NMR: (400MHz, D2O) δ8.52 (s, 2H), 8.19 (s, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.25 (s, 1H), 7.14 (d, J = 5.2Hz, 1H), 3.99 - 4.03 (m, 2H), 3.91 - 3.95 (m, 4H), 3.74 (t, J= 20.0Hz,2H), 3.48 - 3.52 (m, 4H), 2.12 (d, J = 11.2Hz, 2H), 1.66 - 1.78 (m, 2H).

[0248] Intermediate B: 7-(4-(isopropylamino-5-(5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl)pyridine-2- pyrrolo[1,2-b]pyrrolo[3,2-b]pyridazine-3-carboxylonitrile

[0249]

[0250] Intermediate B was prepared in a similar manner to intermediate A, except that in step 1, the isopropylamine was substituted with tetrahydro-2H-pyran-4-amine to give the hydrochloride salt of the title product as a yellow solid. LCMS: m / z = 446.2 (M+H) + . 1 H NMR: (400MHz, MeOD) δ 8.77 (d, J = 2.0Hz, 1H), 8.69 (d, J = 2.4Hz, 1H), 8.56 (s,1H), 8.10 (d, J = 5.2Hz, 1H), 7.90 (s, 1H), 7.24 (d, J = 4.8Hz, 1H), 4.32 -4.29 (m, 1H), 3.97 - 3.94 (d, J = 10.4Hz, 4H), 3.48 - 3.44 (d, J = 14.4Hz, 4H), 1.48 (d, J = 6.4Hz, 6H).

[0251] Intermediate B: Alternative Pathway :

[0252]

[0253] Step 1: N,N-diisopropylethylamine (29.56 mL, 169.68 mmol, 4.0 equivalent) was added to a solution of 2-bromo-1,3,4-thiadiazole (7.29 g, 42.4 mmol, 1.0 equivalent) and piperazine-1-carboxylate tert-butyl ester (19.75 g, 106 mmol, 2.5 equivalent) in n-butanol (83 mL, 0.51 M). The reaction mixture was stirred at 120 °C for 1 hour. The reaction mixture was cooled and concentrated under vacuum. The crude product was purified by chromatography using EtOAc / hexane (0 to 70% gradient) to give 4-(1,3,4-thiadiazole-2-yl)piperazine-1-carboxylate tert-butyl ester (9.93 g, 86% yield) as a pale red solid. LCMS: ESI(+) [M-tBu] + =215.26. 1 H NMR (300MHz, DMSO- d 6) δ 8.84 (s, 1H), 3.46 (m, 8H), 1.42 (s, 9H).

[0254] Step 2: Add 7-{5-bromo-4-[(prop-2-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (5.50 g, 15.4 mmol, 1.0 equivalent), 4-(1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (3.95 g, 13.9 mmol, 0.9 equivalent), and palladium(II) acetate (0.173 g, 0.8 mmol, 0.05... The reaction mixture (in 10.06 g, 30.88 mmol, 2.0 equivalents) was placed in a pressure vessel equipped with a magnetic stirrer, followed by the addition of dimethoxyethane (250 mL, 0.061 M), degassed under vacuum, and backfilled with argon (5×). The reaction mixture was stirred at 105 °C for 24 hours. After cooling, the reaction mixture was filtered through a diatomaceous earth mat and concentrated under vacuum. The crude product was purified by FC elution with DCM / EtOAc (gradient 0-30%), followed by recrystallization from 96% EtOH to a yellow solid of tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(propyl-2-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (2.271 g, 27% yield). LCMS: ESI(+)[M+H] + =546.70. 1H NMR (300MHz, CDCl3) δ 8.76 (s, 1H), 8.51 (s, 1H), 8.36 (s, 1H), 8.21 (d, J = 2.1Hz, 1H), 8.18 (s, 1H), 8.02 (s, 1H), 7.02 (d, J = 4.8Hz, 1H), 3.99 (h, J = 6.4Hz, 1H), 3.63 (s, 8H), 1.51 (s, 9H), 1.43 (d, J = 6.4Hz, 6H).

[0255] Step 3: 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(propyl-2-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (2.27 g, 4.2 mmol, 1.0 equivalent) and 1,1,1,3,3,3-hexafluoro-2-propanol (6.57 mL, 62.4 mmol, 15 equivalent) were placed in a microwave reactor and stirred at 140 °C for 3 hours. The solvent was then evaporated under vacuum. The resulting residue was purified by chromatography, eluting with MeOH / DCM, to give the title compound as a yellow solid (1.615 g, 87% yield). LCMS: ESI(+)[M+H] + =446.03. 1 H NMR (300MHz, DMSO- d 6 ) δ8.83 (d, J = 2.3Hz, 1H), 8.72 (d, J = 2.2Hz, 1H), 8.55 (d, J = 7.1Hz, 1H),8.47 (s, 1H), 8.19 (s, 1H), 7.83 (d, J = 4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 3.92 (h, J = 6.4Hz, 1H), 3.51 - 3.41 (m, 4H), 2.88 - 2.79 (m, 4H), 1.35 (d, J = 6.3Hz, 6H).

[0256] Intermediate C: 7-(4-(methylamino)-5-(5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl)pyridin-2-yl) Pyrrolo[1,2-b]pyrrolopyrazine-3-carboxynitrile

[0257]

[0258] Step 1: To a solution of 2-bromo-4-fluoropyridine (30.0 g, 170 mmol, 1.00 equivalent) in NMP (300 mL), methylamine hydrochloride (13.8 g, 204 mmol, 1.20 equivalent) and DIEA (66.1 g, 511 mmol, 89.1 mL, 3.00 equivalent) was added. The reaction mixture was then stirred at 110 °C for 2 hours. The reaction mixture was poured into H₂O (600 mL) and extracted with DCM (200 mL × 5). The organic layer was washed with saturated NaCl solution (200 mL × 6). The organic layer was then dried over Na₂SO₄, filtered, and concentrated under vacuum to give a yellow liquid of 2-bromo-N-methylpyridine-4-amine (29.2 g, crude). This yellow liquid was used in the next step without any purification. LCMS: m / z = 188.9 (M+H) +

[0259] Step 2: Add 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (31.7 g, 118 mmol, 1.15 equivalents), XPhos Pd G3 (9.60 g, 11.3 mmol, 0.110 equivalents), and K3PO4 (2.00 M, 102 mL, 2.00 equivalents) to a solution of 2-bromo-N-methylpyridin-4-amine (19.2 g, 102 mmol, 1.00 equivalents) in DME (250 mL). Stir the reaction mixture at 100 °C under N2 for 2 hours. Concentrate the reaction mixture under reduced pressure. The resulting residue was purified by silica gel chromatography (DCM / MeOH = 50 / 1 to 10 / 1) to give 7-(4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (16.9 g, 67.5 mmol, 65.7% yield) as a yellow solid. LCMS: m / z = 250.0 (M+H) +

[0260] Step 3: A solution of NBS (10.6 g, 59.4 mmol, 0.88 equivalent) in DCM (177 mL) and ACN (177 mL) was added to a solution of 7-(4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (16.9 g, 67.5 mmol, 1.00 equivalent) in DCM (355 mL) and ACN (355 mL). The reaction mixture was stirred at 0 °C for 1 hour. The reaction mixture was concentrated under reduced pressure. The resulting residue was milled at 25 °C with petroleum ether (30.0 mL) for 30 minutes to give 7-(5-bromo-4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (28.4 g, 75.0 mmol) as a yellow solid. LCMS: m / z = 329.9 (M+H) +

[0261] Step 4: Under N2, add 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bis(1,3,2-dioxane, 1.00 equivalent), KOAc (18.8 g, 191 mmol, 3.00 equivalent), and Pd(PPh3)2Cl2 (6.71 g, 9.6 mmol, 0.150 equivalent) to a solution of 7-(5-bromo-4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (24.2 g, 63.9 mmol, 1.00 equivalent) in dioxane (242 mL) and DMF (121 mL), under N2. The reaction mixture is stirred at 120 °C for 1 hour. The reaction mixture is filtered through diatomaceous earth, and the filtrate is concentrated under vacuum to obtain the residue. The residue was purified by reversed-phase HPLC (0.1% TFA) to give (6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(methylamino)pyridin-3-yl)boronic acid (12.93 g, 29.7 mmol, 46.4% yield, TFA) as a yellow solid. LCMS: m / z = 293.9 (M+H) +

[0262] Step 5: Under N2, add tert-butyl 4-(5-bromo-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylate (3.39 g, 9.6 mmol, 1.05 equivalent), Cs2CO3 (7.47 g, 22.9 mmol, 2.50 equivalent), Xantphos (2.12 g, 3.67 mmol, 0.40 equivalent), and Pd(OAc)2 (412 mg, 1.8 mmol, 0.20 equivalent) to a solution of (6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(methylamino)pyridin-3-yl)boronic acid (4.00 g, 9.2 mmol, 1.00 equivalent, TFA) in dioxane (210 mL), and stir the reaction mixture at 120 °C for 2 hours. The reaction mixture was filtered directly at 120°C, the filter cake was washed with DCM (30.0 mL), and the filtrate was concentrated under vacuum to obtain the residue. The residue was ground with EtOAc (30.0 mL) at 25°C for 30 minutes to give 5.60 g (crude) of 4-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester. LCMS: m / z = 518.1 (M+H) + . 1 H NMR: (400MHz, CDCl3) δ 8.53 (s, 1H), 8.35 (d, J = 2.4Hz, 1H), 8.19(d, J = 2.0Hz, 1H), 8.10 (s, 1H), 7.92 (d, J = 4.8Hz, 1H), 6.99 (s, 1H), 3.62(d, J = 1.6Hz, 8H), 3.12 (d, J = 4.8Hz, 3H), 1.49 (s, 9H).

[0263] Step 6: Add HCl / EtOAc (4.00 M, 28.0 mL, 10.3 equivalents) to a solution of 4-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (5.60 g, 10.8 mmol, 1.00 equivalents) in EtOAc (28.0 mL). Stir the reaction mixture at 25 °C for 1 hour. Filter the reaction mixture; wash the filter cake with DCM (50.0 mL) and concentrate under reduced pressure. The resulting residue was purified by preparative HPLC (under alkaline conditions) to give 7-(4-(methylamino)-5-(5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.13 g, 2.6 mmol, 24.2% yield) as a yellow solid. LCMS: m / z = 418.0 (M+H) + . 1 H NMR (400MHz, DMSO- d 6 ) δ 8.83 (d, J = 2.0Hz, 1H), 8.72 (d, J = 2.0Hz, 1H), 8.51-8.47 (m, 2H), 8.14 (s, 1H), 7.85 (d, J = 5.2Hz, 1H), 7.12 (d, J = 4.4Hz, 1H), 3.45 (t, J = 4.8Hz, 4H), 3.06 (d, J = 4.8Hz, 3H), 2.83 (t, J = 5.2Hz, 4H).

[0264] Intermediate C: Alternative Pathway

[0265]

[0266] Step 1: A solution of methylamine in methanol (9.8 M) (142 mL, 1.42 mol, 10 equivalents) was added to a mixture of 2-bromo-4-fluoropyridine (25.0 g, 0.142 mol, 1.0 equivalents), and the resulting mixture was heated at 80 °C overnight. After completion, the reaction mixture was cooled, all volatiles were evaporated under vacuum, dissolved in EtOAc, and washed with water. The organic layer was dried over sodium sulfate, filtered, and concentrated to give 2-bromo-N-methylpyridine-4-amine (25 g, 89% yield).1 H NMR (300MHz, DMSO- d 6 ), δ: 7.77 (d, J = 5.8Hz, 1H), 6.98 - 6.78 (m, 1H), 6.59 (m, 1H), 6.48 (m, 1H), 2.69 (d, J = 4.9Hz, 3H). LCMS:ESI(+)[M+H] + = 188.94.

[0267] Step 2: Add 2M aqueous solution of K3PO4 (32.1ml, 64.2mmol, 2.0equivalent) to a solution of 2-bromo-N-methylpyridin-4-amine (6.0g, 32.1mmol, 1.0equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxynitrile (12.09g, 44.9mmol, 1.4equivalent), and Xphos G3 (2.17g, 2.6mmol, 0.08equivalent) in anhydrous dimethoxyethane (80ml, 0.4M). Degas the solution with argon for 15 minutes, then heat overnight at 120°C with vigorous stirring. Filter the reaction mixture through a diatomaceous earth mat and evaporate to dryness under reduced pressure. The crude residue was purified by chromatography using methanol / dichloromethane (0-10%) to give 7-[4-(methylamino)-2-pyridyl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (6.1 g, 76% yield) as a yellow solid. 1 H NMR (300MHz, DMSO- d 6 ),δ: 8.79 (d, J = 2.2Hz, 1H,), 8.64 (d, J = 2.2Hz, 1H,), 8.19 (d, J = 5.6,1H,), 7.87 (d, J = 2.3, 1H,), 7.76 (d, J = 4.7Hz, 1H,), 7.08 (d, J = 4.7,1H,), 6.80 (d, J = 5.0, 1H,), 6.45 (m, 1H,), 2.77 (d, J = 4.8Hz, 3H). LCMS:ESI(+)[M+H] + = 250.36.

[0268] Step 3: 7-[4-(methylamino)-2-pyridyl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (5.3 g, 20.1 mmol, 1.0 equivalent) was dissolved in acetonitrile (65 mL, 0.3 M) and dichloromethane (20 mL, 0.7 M), and N-bromosuccinimide (3.57 g, 20.1 mmol, 1.0 equivalent) was added in a single step at room temperature. The reaction mixture was stirred under ambient conditions for 30 min. The reaction progress was monitored by LCMS. After completion, the mixture was evaporated under reduced pressure, and the resulting residue was purified by chromatography using 0–5% ethyl acetate / dichloromethane to give 7-(5-bromo-4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (5.95 g, 88% yield) as a yellow solid. 1 H NMR (300MHz, DMSO- d 6 ), δ: 8.80 (d, J= 2.2Hz, 1H), 8.67 (d, J = 2.2Hz, 1H), 8.36 (s, 1H), 7.94 (s, 1H), 7.76 (d, J= 4.8Hz, 1H), 7.08 (d, J = 4.8Hz, 1H), 6.45 (q, J = 4.3Hz, 1H), 2.90 (d, J =4.7Hz, 3H). LCMS:ESI(+)[M+H] + = 330.16.

[0269] Step 4: Prepare tert-butyl 4-(1,3,4-thiadiazol-2-yl)piperazine-1-carboxylate in the same manner as in Step 1 of intermediate B (alternative route). 1 H NMR (300MHz, DMSO- d 6 ), δ: 8.84 (s, 1H), 3.46 (s, 8H), 1.42 (s, 9H). LCMS:ESI(+)[M+2H] + = 272.16.

[0270] Step 5: Dissolve 7-[5-bromo-4-(methylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (0.5 g, 1.52 mmol, 1.0 equivalent), palladium(II) acetate (0.051 g, 0.23 mmol, 0.15 equivalent), and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.26 g, 0.5 mmol, 0.3 equivalent) Cesium carbonate (0.1 g, 3.1 mmol, 2.0 equivalents) and cuprous iodide (0.087 g, 0.5 mmol, 0.3 equivalents) were placed in an oven-dried screw-cap vial, and tert-butyl 4-(1,3,4-thiadiazol-2-yl)piperazine-1-carboxylate (0.434 g, 1.5 mmol, 1 equivalent) and anhydrous dioxane (25.39 ml, 0.06 M) were added. The reaction tube was evacuated, backfilled with argon for 20 minutes, sealed, and stirred overnight at 105 °C. After the reaction was complete (confirmed by UPLC), all volatiles were evaporated under vacuum and the resulting residue was purified by chromatography (0 to 31 ethyl acetate / dichloromethane) to give tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)-pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (0.57 g, 61% yield) as a yellow crystalline solid. 1 H NMR (300MHz, DMSO-) d 6 ), δ: 8.83 (s, 1H), 8.73 (s, 1H), 8.48 (m, 2H), 8.14 (s, 1H), 7.86 (s,1H), 7.12 (d, J = 4.8Hz, 1H), 3.54 (s, 8H), 3.06 (d, J = 4.9Hz, 3H), 1.44 (s,9H). LCMS:ESI(+)[M+H] + = 518.64.

[0271] Step 6: A solution of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)-pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (0.25 g, 0.5 mmol, 1 equivalent) in 1,1,1,3,3,3-hexafluoro-2-propanol (0.769 mL, 7.3 mmol, 15 equivalents) was microwaved at 140 °C for 3 hours. Afterwards, all volatiles were evaporated under reduced pressure, and the remaining residue was purified by chromatography (0 to 7% methanol / dichloromethane) to give the title product (0.15 g, 73% yield) as a yellow solid. LCMS: ESI(+)[M+H] += 418.06. 1 H NMR (300MHz, DMSO-) d 6 ), δ: 8.83 (d, J = 2.2Hz, 1H), 8.72 (s, 1H), 8.54 - 8.42 (m, 2H), 8.13(s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 3.46 (s, 4H), 3.06 (d, J = 4.9Hz, 3H), 2.84 (s, 4H), 2.61 (m, 1H).

[0272] Intermediate D: 7-[5-(5-{4-formylbicyclo[2.2.2]oct-1-yl}-1,3,4-thiadiazol-2-yl)-4- [(oxan-4-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0273]

[0274] Step 1: A solution of methyl 4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]octane-1-carboxylate (6 g, 13 mmol, 1 equivalent) in anhydrous THF (324.5 mL, 0.04 M) was cooled to -15 °C under an argon atmosphere and treated with DIBAL-H (38.96 mL of 1.0 M THF solution, 39 mmol, 3 equivalent). After 30 minutes, the cooling bath was removed, the mixture was warmed to room temperature, and stirred for 3 hours. The reaction mixture was quenched by adding MeOH (40 mL) and stirred vigorously for 20 minutes, followed by the addition of a saturated aqueous solution of Rochelle salt. The reaction mixture was extracted with EtOAc. The combined organic layers were washed with brine and concentrated under reduced pressure. The crude product was purified by silica gel chromatography (0 to 10%, acetone / DCM) to obtain a grayish-white solid of [4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]-oct-1-yl]methanol (3.65 g, 65% yield). LCMS: ESI(+)[M+H] + = 435.54. 1 H NMR (300MHz, DMSO-) d 6 ), δ: 8.91 (d, J = 7.7Hz, 1H), 8.42 (s, 1H), 7.05 (s, 1H), 4.46 (t, J = 5.4Hz, 1H), 3.86 (m, 3H), 3.52 (t, J= 11.0Hz, 2H), 3.14 (dd, J = 20.1, 5.3Hz, 2H), 2.00 - 1.87 (m, 8H), 1.55 - 1.39 (m, 8H).

[0275] Step 2: Add [4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]-oct-1-yl]methanol (3.78 g, 8.3 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (2.70 g, 9.9 mmol, 1.2 equivalent) and Pd(dppf)Cl2 CH2Cl2 (1.69 g, 2.1 mmol, 0.25 equivalence) was added to a solution of anhydrous dioxane (212 mL, 0.04 M) with 2 M K2CO3 aqueous solution (8.5 mL, 16.6 mmol, 2.0 equivalence). The mixture was degassed with argon for 30 min and then stirred overnight at 120 °C. The reaction mixture was diluted with DCM, filtered through a diatomaceous earth mat, washed with DCM / MeOH (1:1), and concentrated under reduced pressure. The crude product was purified by rapid chromatography (DCM / acetone) to give [4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]oct-1-yl]methanol (3.3 g, 73% yield). LCMS: ESI(+)[M+H] + =542.67. 1 H NMR (300MHz, DMSO- d 6 ), δ: 8.84 (m, 3H), 8.69 (s, 1H), 8.32 (s, 1H), 7.86 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 4.46 (t, J = 5.4Hz, 1H), 3.94 (d, J = 15.3Hz, 3H), 3.60 (t, J = 10.2Hz, 2H), 3.11 (d, J = 5.4Hz, 2H), 2.11 - 1.88 (m, 9H), 1.49 (s, 8H).

[0276] Step 3: Add Dysmart periodide (3.36 g, 8.0 mmol, 1.3 equivalent) to a solution of [4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]oct-1-yl]methanol (3.3 g, 6.1 mmol, 1 equivalent) in DCM (609 mL, 0.01 M). Stir the reaction mixture at room temperature for 2 hours, then quench with a 20% aqueous solution of Na₂S₂O₃ and a saturated aqueous solution of NaHCO₃. Stir the mixture until the aqueous layer becomes clear. Then extract the latter with DCM. Wash the combined organic layers with a saturated aqueous solution of NaHCO₃, water, and brine, dry to Na₂SO₄, and concentrate under reduced pressure. The crude product was ground with Et₂O, filtered, and washed on the filter with a mixture of DCM / Et₂O (1:1), Et₂O, and pentane to give the title compound (2.8 g, 84% yield). LCMS: ESI(+)[M+H] + =540.20. 1 H NMR (300MHz, DMSO- d 6 ),δ: 9.49 (s, 1H), 8.90 - 8.73 (m, 3H), 8.70 (s, 1H), 8.32 (s, 1H), 7.86 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 3.95 (d, J = 11.7Hz, 3H), 3.60 (t, J =10.3Hz, 2H), 2.18 - 1.96 (m, 8H), 1.78 (d, J = 8.1Hz, 6H), 1.60 (q, J = 11.9, 9.9 Hz, 2H).

[0277] Intermediate E: 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxane-4-yl)amino]pyridinium [Pinidin-3-yl]-1,3,4-thiadiazol-2-yl]bicyclo[2.2.2]octane-1-carboxylic acid

[0278]

[0279] Step 1: DIPEA (220 mL, 1.26 mol, 2.6 equivalents) was added to methyl 4,6-dichloronicotinate (100 g, 485 mmol, 1.0 equivalents) in a cooled, stirred solution of ACN (486 mL, 1 M). Tetrahydro-2H-pyran-4-amine (65 mL, 631 mmol, 1.3 equivalents) was added dropwise, and the mixture was stirred at 70 °C for 36 hours. The mixture was cooled, the solids were filtered off, and the filtrate was concentrated under vacuum. The residue was partitioned between EtOAc and water. The organic layer was washed with brine, dried over Na2SO4, and concentrated under reduced pressure. The resulting residue was recrystallized from hexane to give methyl 6-chloro-4-[(oxan-4-yl)amino]pyridine-3-carboxylate (124.8 g, 92% yield). LCMS: ESI(+)[M+H] + = 272.25. 1 H NMR (300MHz, DMSO- d 6 δ: 8.54 (s, 1H), 8.06 (d, J = 7.9Hz, 1H), 7.00 (s, 1H), 3.84 (s, 6H), 3.48 (td, J =11.4, 2.0Hz, 2H), 1.90 (d, J = 10.7Hz, 2H), 1.46 (qd, J = 11.1, 4.5Hz, 2H).

[0280] Step 2: 65% by weight hydrazine monohydrate (88 mL, 1.18 mol, 8.0 equivalent) was added to a solution of methyl 6-chloro-4-[(oxan-4-yl)amino]pyridine-3-carboxylate (40 g, 147.7 mmol, 1.0 equivalent) in EtOH (246 mL), and the mixture was stirred at 80 °C for 2 hours. The evaporator was evaporated and then co-evaporated several times with toluene. The residue was dried overnight at 50 °C and 5 mbar to give 6-chloro-4-[(oxan-4-yl)amino]pyridine-3-carbazide (37.6 g, 89% yield). LCMS: ESI(+)[M+H] + = 272.05. 1 H NMR (300MHz, DMSO- d 6) δ: 9.87 (s, 1H), 8.40 (d, J =7.8Hz, 1H), 8.27 (s, 1H), 6.84 (s, 1H), 4.49 (s, 2H), 3.91 - 3.78 (m, 2H), 3.77 - 3.64 (m, 1H), 3.58 - 3.39 (m, 2H), 1.89 (d, J = 12.1Hz, 2H), 1.39 (qd,J = 10.7, 4.2Hz, 2H).

[0281] Step 3: Add DIPEA (70 mL, 399 mmol, 3.0 equivalent) and HATU (60.7 g, 159.6 mmol, 1.2 equivalent) to a solution of 1,4-cyclohexanedicarboxylate (31 g, 146 mmol, 1.1 equivalent) in DMF (460 mL), followed by fractional addition of 6-chloro-4-[(oxapan-4-yl)amino]pyridine-3-carbazide (37.6 g, 133 mmol, 1.00 equivalent). Stir the mixture at 25 °C for 1.5 h. Quench the reaction mixture with water and ice (600 mL) and extract with EtOAc. Wash the organic layer with aqueous NaHCO3 solution, aqueous KHSO4 solution, water, and brine, dry to Na2SO4, and concentrate under reduced pressure. The crude product was purified by column chromatography with elution using DCM / MeOH (0-10%) to give methyl 4-(N'-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-carbonyl}hydrazinoyl)bicyclo[2.2.2]octane-1-carboxylate (45 g, 72% yield). LCMS: ESI(+)[M+H] + = 465.5. 1 H NMR (300MHz, DMSO-) d 6 ) δ: 10.30 (s, 1H), 9.51 (s, 1H), 8.39 (s, 1H), 8.29 (d, J =7.9Hz, 1H), 6.90 (s, 1H), 4.10 (d, J = 4.8Hz, 1H), 3.90 - 3.78 (m, 2H), 3.78- 3.66 (m, 1H), 3.59 (s, 3H), 3.55 - 3.38 (m, 2H), 3.17 (d, J = 4.0Hz, 2H), 1.88 (d, J = 10.8Hz, 2H), 1.76 (s, 12H), 1.49 - 1.30 (m, 2H).

[0282] Step 4: Under vigorous stirring at 40°C, Lawson's reagent (1.5 equivalents) was added in portions to a solution of methyl 4-(N'-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-carbonyl}hydrazinoyl)bicyclo[2.2.2]octane-1-carboxylate (45 g, 1 equivalent) in anhydrous THF (0.06 M). The resulting suspension was stirred at 75°C for 2 hours. Upon completion, the evaporation was evaporated and the residue was dissolved in DCM. The resulting solution was washed with aqueous K₂CO₃ solution and concentrated under reduced pressure. The crude product was purified by chromatography (EtOAc / DCM, 0 to 10%) to give methyl 4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]octane-1-carboxylate (15.6 g, 35% yield). LCMS: ESI(+)[M+H] + = 463.6. 1 H NMR (300MHz, DMSO- d 6 ) δ: 8.89 (d, J = 7.8Hz, 1H), 8.44 (s, 1H), 7.06 (s,1H), 3.98 - 3.71 (m, 3H), 3.62 (s, 3H), 3.52 (t, J = 10.1Hz, 2H), 2.09 - 1.77 (m, 14H), 1.58 - 1.38 (m, 2H).

[0283] Step 5: Dissolve methyl 4-(5-{6-chloro-4-[(oxan-4-yl)amino]pyridin-3-yl}-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]octane-1-carboxylate (5 g, 10.8 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (3.78 g, 14 mmol, 1.3 equivalent), and CsOAc (6.4 g, 32.4 mmol, 3 equivalent) in anhydrous THF (216 ml, 0.05 M). The solution was degassed with argon for 15 minutes, and a complex of [1,1-bis(diphenylphosphino)ferrocene]dichloropalladium(II) and dichloromethane (2.22 g, 2.7 mmol, 0.25 equivalents) was added. The pressure vessel was sealed and stirred at 90 °C overnight. The reaction mixture was filtered through a diatomaceous earth filter and washed with DCM and MeOH. The solvent was concentrated under reduced pressure, and the residue was purified by column chromatography (5% to 50%, ACN / DCM) to give methyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxane-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]bicyclo[2.2.2]octane-1-carboxylate (5.1 g, 80% yield). LCMS: ESI(+) [M+H] + = 570.69. 1 H NMR (300MHz, DMSO-) d 6 ) δ: 8.86 (d, J = 2.2Hz, 1H), 8.81 (d, J = 7.1Hz, 1H), 8.79(d, J = 2.2Hz, 1H), 8.71 (s, 1H), 8.34 (s, 1H), 7.86 (d, J = 4.9Hz, 1H), 7.13(d, J = 4.8Hz, 1H), 4.04 - 3.81 (m, 3H), 3.67-3.45 (m, 5H), 2.21 - 2.08 (m,2H), 2.07 - 1.80 (m, 12H), 1.60 (q, J = 10.1Hz, 2H).

[0284] Step 6: Methyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]bicyclo[2.2.2]octane-1-carboxylate (4.1 g, 7.2 mmol, 1 equivalent) was added to a solution of pyridine (72 mL, 0.1 M) with lithium iodide (9.73 g, 72 mmol, 10 equivalents), and the resulting mixture was stirred at 150 °C for 20 h. The reaction mixture was concentrated under vacuum and acidified with an equimolar amount of dilute HCl. The resulting residue was purified by column chromatography (0 to 15%, IPA / DCM) to give the title compound (1.25 g, 30% yield). LCMS: ESI(+)[M+H] + =556.20. 1 H NMR (300MHz, DMSO- d 6 ) δ: 12.22 (s, 1H), 9.51 (s, 1H), 8.96 (d, J =2.1Hz, 1H), 8.86 (d, J = 2.2Hz, 1H), 8.77 (s, 1H), 8.16 (s, 1H), 8.03 (d, J =5.0Hz, 1H), 7.22 (d, J = 4.9Hz, 1H), 4.08 (s, 1H), 4.01 - 3.89 (m, 2H), 3.60(t, J = 10.2Hz, 2H), 2.16 - 1.78 (m, 14H), 1.75 - 1.56 (m, 2H).

[0285] Intermediate F: 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4- (oxane-4-ylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0286]

[0287] The title compound was synthesized according to the same procedure as described for intermediate T, except that tert-butyl 3,8-diazabicyclo[3.2.1]octane-8-carboxylate was used instead of tert-butyl 4,7-diazaspiro[2.5]octane-4-carboxylate as the starting material. LCMS C 26 H 27 Theoretical N9OS value: 513.2, measured value: m / z = 514.3 [M+H] + .

[0288] Intermediate G: 7-[5-(5-{2,7-diazaspiro[3.5]non-2-yl}-1,3,4-thiadiazol-2-yl)-4-(methyl) [amino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0289]

[0290] Step 1: A suspension of 2,5-dibromo-1,3,4-thiadiazole (970 mg, 4.0 mmol, 1.0 equivalent), tert-butyl 2,7-diazaspiro[3.5]nonane-7-carboxylate (990 mg, 4.4 mmol, 1.1 equivalent), and DIPEA (1.038 mL, 4.6 mmol, 1.5 equivalent) in dioxane (15 mL, 0.21 M) was stirred at 120 °C for 1 hour. The reaction mixture was diluted with water (10 mL) and extracted with DCM (20 mL). The crude material was purified by rapid chromatography with hexane / EtOAc elution to give the desired compound (1.54 g, 96% yield) as a yellow oil. LCMS: ESI(+)[M+H] + =391.3 1 H NMR (300MHz, DMSO- d 6 ) δ3.83 (s, 4H), 3.31 - 3.21 (m, 4H), 1.75 - 1.62 (m, 4H), 1.39 (s, 9H).

[0291] Step 2: In a pressure vessel, 7-[5-bromo-4-(methylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.5 g, 4.6 mmol, 1.0 equivalent) was dissolved in dioxane (25 ml), followed by the addition of bis(pinacol)diboron (1.39 g, 5.49 mmol, 1.2 equivalent) and KOAc (0.89 g, 9.14 mmol, 2.0 equivalent). The solution was bubbled with argon for 7 minutes, and Pd(dppf)Cl2 was added. DCM (0.375 g, 0.46 mmol, 0.1 equivalent) was then bubbled. The reaction mixture was then transferred to a preheated oil bath and stirred overnight at 90 °C. UPLC showed product formation. The reaction mixture was filtered through a diatomaceous earth filter cake and evaporated to dryness. The crude product was used in the next step without further purification. LCMS: ESI(+)[M+H] + =294.2.

[0292] Step 3: In a pressure vessel, tert-butyl 2-(5-bromo-1,3,4-thiadiazol-2-yl)-2,7-diazaspiro[3.5]nonane-7-carboxylate (1.377 g, 2.57 mmol, 1.0 equivalent) and 7-[4-(methylamino)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.0 g, 2.5 mmol, 1.0 equivalent) in a solution of dioxane (13 ml, 0.2 M) were added, along with cesium carbonate (2.09 g, 6.42 mmol, 2.5 equivalent) and palladium(II) acetate (0.115 g, 0.51 mmol, 0.2 equivalent). The reactants were bubbled with argon for 7 minutes, followed by the addition of Xantphos (0.59 g, 1.03 mmol, 0.4 equivalence). The solution was degassed with argon for 3 minutes and then stirred overnight at 120 °C. LC-MS showed product formation. The reaction mixture was filtered through a diatomaceous earth filter cake and evaporated to dryness. The crude product was purified by column chromatography, eluting with DCM / MeOH (0–10%), to give 0.415 g (29% yield) of the desired product. LC-MS: ESI(+)[M+H] + =558.8. 1 H NMR (300MHz, DMSO-) d 6) δ 8.83 (d, J = 2.2Hz, 1H), 8.73 (d, J = 2.2Hz, 1H), 8.48(s, 2H), 8.14 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 3.91(s, 4H), 3.06 (d, J = 4.8Hz, 3H), 1.75 (t, J = 5.6Hz, 4H), 1.40 (s, 9H).

[0293] Step 4: In a sealed reactor, 0.2 g (0.36 mmol, 1.0 equivalent) of 2-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-2,7-diazaspiro[3.5]nonane-7-carboxylic acid tert-butyl ester was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (1.13 mL, 30 equivalent) and microwaved at 150 °C for 2 hours. UPLC showed complete deprotection of the starting material. The solvent was evaporated to dryness, and the solid was ground with Et2O to give 146 mg (87% yield) of the desired product as a yellow solid. LCMS: ESI(+)[M+H] + = 458.08. 1 H NMR (300MHz, DMSO-) d 6) δ 8.83 (d, J = 2.2Hz, 1H), 8.72 (d, J = 2.2Hz, 1H), 8.47(s, 2H), 8.13 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 3.86(s, 4H), 3.06 (d, J = 4.8Hz, 3H), 2.63 (t, J = 5.4Hz, 4H), 1.87 - 1.60 (m, 4H).

[0294] Intermediate H: 7-(5-(5-([4,4) ' [-Bioperidin]-1-yl)-1,3,4-thiadiazol-2-yl)-4-(methylamino) Pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0295]

[0296] The title compound was synthesized according to the same procedure as described for intermediate T, except that tert-butyl [4,4'-bipiperidine]-1-carboxylate was used instead of tert-butyl 4,7-diazaspiro[2,5]octane-4-carboxylate as the starting material. LCMSC 26 H 29 Theoretical value of N9S: 499.2, measured value: m / z = 500.4 [M+H] + .

[0297] Intermediate I: 7-[4-(methylamino)-5-{5-[(1r,4r)-4-(methylamino)cyclohexyl]-1,3,4-thiadi [Azol-2-yl]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0298]

[0299] Step 1: Methyl trans-4-(tert-butoxycarbonylamino)cyclohexanecarboxylate (3.0 g, 11.66 mmol, 1.0 equivalent) was dissolved in DMF (20 mL, 0.6 M) and cooled to 0 °C. NaH (0.536 g, 13.99 mmol, 1.2 equivalent) was then added, and the reaction mixture was stirred at 0 °C for 30 min. Methyl iodine (1.09 mL, 17.49 mmol, 1.5 equivalent) was added, the cooling bath was removed, and the reaction mixture was stirred overnight at room temperature. TLC showed the formation of new spots. The mixture was poured into a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate. The crude product was purified by hexane:EtOAc to give 1.4 g (44% yield) of the desired product. 1 H NMR (300MHz, DMSO- d 6) δ 3.58 (s, 3H), 2.64 (s, 3H), 2.25 (tt, J =11.7, 3.6Hz, 1H), 1.94 (dt, J = 12.3, 2.6Hz, 2H), 1.60 - 1.41 (m, 4H), 1.38(d, J = 1.6Hz, 12H).

[0300] Step 2: Methyl (1r,4r)-4-{[(tert-butoxy)carbonyl](methyl)amino}cyclohexane-1-carboxylate (1.3 g, 4.79 mmol, 1.0 equivalent) was dissolved in THF (18 mL, 0.27 M), followed by the addition of LiOH solution (4.8 mL, 4.79 mmol, 2.0 equivalent) and stirring at room temperature for 5 hours. Then, another portion of LiOH (2.4 mL, 2.39 mmol, 1.0 equivalent) was added and the reaction mixture was stirred overnight. The reaction mixture was then quenched with saturated KHSO4 solution to pH < 5 and extracted with DCM to give 1.18 g (96% yield) of the desired product in free acid form. 1 H NMR (300MHz, DMSO- d 6) δ 3.90- 3.52 (m,1H) 2.65 (s, 3H), 2.13 (tt, J = 11.7, 3.6Hz, 1H), 2.02 - 1.91 (m, 2H), 1.66 -1.45 (m, 4H), 1.39 (d, J = 1.2Hz, 11H).

[0301] Step 3: Add DIPEA (2.2 mL, 12.56 mmol, 3.0 equivalent) and HATU (1.91 g, 5.02 mmol, 1.2 equivalent) to a solution of 6-chloro-4-(methylamino)pyridine-3-carbazide (0.84 g, 0.7975 mmol, 1.0 equivalent) and (1r,4r)-4-{[(tert-butoxy)carbonyl]amino}cyclohexane-1-carboxylic acid (1.19 g, 4.61 mmol, 1.1 equivalent) in DMF (10 mL). Stir the mixture at 25 °C for 1 hour. UPLC showed the mass of the desired product. Quench the reaction mixture with water and extract with ethyl acetate. Wash the combined organic layers with water and brine, dry to Na2SO4 and concentrate to give the crude product. Purify the crude product by column chromatography, eluting with DCM:MeOH (0-10%), to give 1.18 g (64% yield) of the desired product. LCMS: ESI(+)[M+H] + =440.6. 1 H NMR (300MHz, DMSO- d 6) δ 10.30 (s, 1H), 9.78 (s, 1H), 8.33 (s, 1H), 8.11 (s, 1H), 6.66 (s, 1H), 2.82 (d, 3H), 2.65 (s, 3H), 2.13 (tt, J = 11.7, 3.6Hz, 1H), 2.02 - 1.91 (m, 2H), 1.66 - 1.45 (m, 4H), 1.39 (d, J =1.2Hz, 12H).

[0302] Step 4: Lawson's reagent (1.20 g, 2.95 mmol, 1.1 equivalent) was added to a suspension of N-methyl-N-[(1r,4r)-4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazinoyl}cyclohexyl]tert-butyl carbamate (1.18 g, 2.68 mmol, 1.0 equivalent) in anhydrous toluene (50 mL, 0.05 M). The reaction mixture was stirred under reflux for 1.5 h, then quenched with water, washed with saturated NaHCO3 solution, extracted with DCM, and concentrated under reduced pressure. The crude product was purified by rapid column chromatography (DCM / MeOH) to give 0.7 g (60% yield) of the desired product as a white solid. LCMS: ESI(+)[M+H] + =438.6. 1 HNMR (300MHz, DMSO- d 6) δ 8.66 (d, J= 5.0Hz, 1H), 8.40 (s, 1H), 6.83 (s, 1H), 3.25 - 3.09 (m, 1H), 2.98 (d, J = 4.9Hz, 3H), 2.71 (s, 3H), 2.21 (d, J =10.3Hz, 2H), 1.69 (d, J = 7.4Hz, 6H), 1.41 (s, 9H).

[0303] Step 5: Add tert-butyl carbamate (0.7 g, 1.6 mmol, 1.0 equivalent) to N-methyl-N-[(1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexyl]carbamate (0.7 g, 1.6 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.6 g, 2.23 mmol, 1.4 equivalent) and Pd(dppf)Cl2 CH₂Cl₂ (0.328 g, 0.4 mmol, 0.25 equivalences) was added to a solution of anhydrous dioxane (30 mL) with 2 M K₂CO₃ (1.6 mL, 3.2 mmol, 2.0 equivalences). The solution was degassed with argon for 2–3 min, then heated to 120 °C and stirred overnight. UPLC showed complete conversion of the starting material. The resulting solution was diluted with MeOH, filtered through a diatomaceous earth mat, and concentrated to dryness. The crude product was purified by chromatography, eluting with DCM:MeOH (0–10%), to give 0.7 g (80% yield) of the desired product. LCMS: ESI(+)[M+H] + =546.1. 1 H NMR (300MHz, DMSO- d 6) δ 8.85 (d, J = 2.2Hz, 1H), 8.74 (d, J = 2.2Hz, 1H), 8.71 - 8.58 (m, 2H), 8.19 (s, 1H), 7.88 (d, J =4.8Hz, 1H), 7.13 (d, J = 4.8Hz, 1H), 3.24 - 3.15 (m, 1H), 3.09 (d, J= 4.9Hz,3H), 2.71 (s, 3H), 2.30 - 2.12 (m, 2H), 1.76 - 1.53 (m, 6H), 1.42 (s, 9H).

[0304] Step 6: In a closed cup reactor, 0.67 g (1r,4r)-4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]cyclohexyl]tert-butyl carbamate was dissolved in hexafluoro-2-propanol (4.0 mL, 30.0 equivalents) and microwaved at 150 °C for 2 hours. UPLC showed complete deprotection of the starting material. The solvent was evaporated to dryness to give 0.54 g (99% yield) of the desired product as a yellow solid. LCMS: ESI(+)[M+H] + =444.97. 1 H NMR (300MHz, DMSO- d 6) δ 8.84 (d, J = 2.3Hz, 1H), 8.73 (d, J = 2.2Hz, 1H), 8.68 - 8.47 (m, 2H), 8.18 (s, 1H), 7.88 (d, J = 4.8Hz, 1H), 7.13 (d, J = 4.8Hz, 1H), 3.20 - 3.10 (m, 1H), 3.09(d, J = 4.8Hz, 3H), 2.36 - 2.26 (m, 4H), 2.20 - 2.08 (m, 2H), 2.07 - 1.96 (m,2H), 1.70 - 1.49 (m, 3H), 1.33 - 1.11 (m, 2H).

[0305] Intermediate J: 7-[4-(methylamino)-5-{5-[4-(piperazin-1-yl)piperidin-1-yl]-1,3,4-thiadiazole-2- [pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0306]

[0307] The title compound was synthesized according to the same procedure as described for intermediate T, except that tert-butyl 4-(piperidin-4-yl)piperazine-1-carboxylate was used instead of tert-butyl 4,7-diazaspiro[2.5]octane-4-carboxylate as the starting material. LCMSC 25 H 28 N 10Theoretical value of S: 500.2, measured value: m / z = 501.4 [M+H] + .

[0308] Intermediate K: 7-(5-(5-(4-aminobicyclo[2.2.2]oct-1-yl)-1,3,4-thiadiazol-2-yl)-4-(methyl) (amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0309]

[0310] Step 1: At 0°C, methylamine (288 g, 2.32 mol, 25% purity, 5.03 equivalents) was slowly added to a solution of methyl 4,6-dichloronicotinic acid (95.0 g, 461 mmol, 1.00 equivalents) in 1000 mL of ACN. The mixture was stirred at 0°C for 0.5 h, and then at 25°C for 2 h. The reaction mixture was concentrated under reduced pressure and extracted with ethyl acetate (500 mL × 3). The combined organic layers were washed with brine (500 mL × 2), dried over Na2SO4, filtered, and the filtrate was concentrated under reduced pressure to give the crude product. The crude product was subjected to column chromatography (SiO2, petroleum ether:ethyl acetate = 20:1-10:1, R... f = 30) Purification. The desired product was given as a white solid (39.0 g, 184 mmol, 40.0% yield). LCMS: m / z = 201.1 (M+H) + .

[0311] Step 2: NH₂NH₂·H₂O (86.6 g, 1.47 mol, 84.1 mL, 7.97 equivalents) was added to a solution of methyl 6-chloro-4-(methylamino)nicotinic acid (39.0 g, 184 mmol, 1.00 equivalents) in EtOH (300 mL). The mixture was stirred at 80 °C for 3 hours. The reaction mixture was concentrated and extracted with ethyl acetate (500 mL × 4). The combined organic layers were washed with brine (500 mL × 4), dried over Na₂SO₄, and concentrated to give the crude product. The crude product was ground with petroleum ether / ethyl acetate = 15:1 (600 mL). The desired product (27.0 g, 120 mmol, 65.2% yield) was given as a white solid. LCMS: m / z = 201.2 (M+H) +

[0312] Step 3: At 25°C, DIEA (13.8 g, 107 mmol, 18.6 mL, 1.20 equivalent) and HATU (16.2 g, 42.8 mmol, 1.20 equivalent) were added to a solution of 6-chloro-4-(methylamino)nicotinamide (8.00 g, 35.6 mmol, 1.00 equivalent) and 4-(((l1-methyl)(l1-oxoalkyl)boryl)amino)bicyclo[2.2.2]octane-1-carboxylic acid (10.5 g, 39.2 mmol, 1.10 equivalent) in DMF (100 mL), and the mixture was stirred at 25°C for 1 hour. The reaction mixture was poured into water (100 mL) and extracted with ethyl acetate (100 mL × 3). The combined organic layers were washed with water (100 mL × 3) and brine (200 mL), dried, and concentrated to give the crude product. The crude product was purified by preparative HPLC. The desired product was obtained as a white solid (15.0 g, 32.0 mmol, 89.7% yield). LCMS: m / z = 452.4 (M+H) +

[0313] Step 4: Lawson's reagent (14.2 g, 35.2 mmol, 1.10 equivalence) was added to a solution of N'-(4-(((l1-methyl)(l1-oxoalkyl)boranealkyl)amino)bicyclo[2.2.2]octane-1-carbonyl)-6-chloro-4-(methylamino)nicotinamide (15.0 g, 32.0 mmol, 1.00 equivalence) in THF (300 mL), and the mixture was stirred at 90 °C for 2 h. The reaction mixture was concentrated to give the crude product. The crude product was purified by preparative HPLC. The desired product (4.30 g, 9.33 mmol, 29.1% yield) was given as a grayish-white solid. LCMS: m / z = 450.3 (M+H) +

[0314] Step 5: Under N2, add Pd(dppf)Cl2 to a solution of (4-(5-(6-chloro-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)bicyclo[2.2.2]oct-1-yl)carbamate (3.80 g, 8.44 mmol, 1.00 equivalent), (3-cyanopyrrolo[1,2-b]pyridazin-7-yl)boric acid (2.37 g, 12.67 mmol, 1.50 equivalent) and K3PO4 (2 M, 8.44 mL, 2.00 equivalent) in DME (4.00 mL). CH2Cl2 (689 mg, 844 µmol, 0.10 equivalents). The resulting mixture was stirred at 110 °C for 12 hours. The reaction mixture was filtered, and the filtrate was extracted with DCM (80.0 mL × 3). The combined organic phases were washed with brine (100 mL), dried over anhydrous Na2SO4, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (SiO2, petroleum ether / ethyl acetate = 10 / 1 to DCM / ethyl acetate = 1 / 1) to give the residue. The residue and a dioxane (4 M, 4.00 mL, 4.53 equivalents) solution were stirred at 25 °C for 12 hours. The mixture was concentrated under vacuum. The EtOAc solution of the residue was heated to 90 °C for 30 minutes and filtered three times to give a brown solid of 7-(5-(5-(4-aminobicyclo[2.2.2]oct-1-yl)-1,3,4-thiadiazol-2-yl)-4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.67 g, 3.22 mmol, 33.7% yield, HCl). LCMS: m / z = 557.2.

[0315] Intermediate L: 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4- (methylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0316]

[0317] Step 1: A stirred suspension of 2,5-dibromo-1,3,4-thiadiazole (1.05 g, 4.31 mmol, 1.0 equivalent), 8-Boc-3,8-diaza-bicyclo[3.2.1]octane (1.005 g, 4.73 mmol, 1.1 equivalent), and N,N-diisopropylethylamine (1.125 ml, 6.46 mmol, 1.5 equivalent) in anhydrous dioxane (21.53 ml, 0.2 M) was heated at 120 °C for 1 hour. The reaction mixture was diluted with water, extracted with DCM, and the organic phase was concentrated on silica gel. The crude material was purified by rapid chromatography using an EtOAc / hexane gradient to obtain a yellow oily substance, 7-[5-bromo-4-(methylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (0.819 g, 2.18 mmol, 71%). LCMS: ESI(+) [M+H] + = 337.3. 1 H NMR (300MHz, CDCl3) δ 4.37 (s, 2H), 3.72 - 3.26 (m, 4H), 2.03 (m, 2H), 1.82 (m, 2H), 1.50 (d, J = 0.8Hz, 9H).

[0318] Step 2: In a pressure reactor, 7-[5-bromo-4-(methylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.5 g, 4.57 mmol, 1.0 equivalent) was dissolved in dioxane (25 ml, 0.18 M), followed by the addition of bis(pinacol)diboron (1.39 g, 5.49 mmol, 1.2 equivalent) and KOAc (1.39 g, 14.17 mmol, 3.1 equivalent). The solution was bubbled with argon for several minutes, and Pd(dppf)Cl2 was added. DCM (0.373 g, 0.46 mmol, 0.1 equivalent) was then bubbled repeatedly. The reaction mixture was then transferred to a preheated oil bath and stirred overnight at 90 °C. The reaction mixture was filtered through a diatomaceous earth pad and evaporated to dryness. The crude product was used in the next step without further purification.

[0319] Step 3: Add Cs2CO3 (1.26 g, 3.86 mmol, 2.5 equivalents) and Xantphos (0.358 g, 0.62 mmol, 0.4 equivalents) to a solution of 7-[4-(methylamino)-5-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)pyridin-2-yl]pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.58 g, 1.55 mmol, 1.0 equivalents), 3-(5-bromo-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.638 g, 1.70 mmol, 1.1 equivalents) in dioxane (40 ml, 0.04 M). The reactants were bubbled with argon for several minutes, followed by the addition of Pd(OAc)₂ (0.069 g, 0.31 mmol, 0.2 equivalents). The solution was degassed with argon for 2–3 minutes, then stirred overnight at 120 °C. The reaction mixture was filtered through a diatomaceous earth mat and evaporated to dryness. The crude product was purified by FC chromatography, eluting with DCM / MeOH (0–10%). The major fraction was repurified by pTLC, eluting with DCM / MeOH (0–10%), and finally ground with Et₂O to give 0.190 g (23% yield) of the desired product. LCMS: ESI(+)[M+H] + = 544.77. 1 H NMR (300MHz, DMSO- d 6) δ: 8.83 (d, J = 2.2Hz, 1H), 8.72 (d, J = 2.3Hz, 1H), 8.51 - 8.43 (m, 2H), 8.14 (s, 1H), 7.85 (d, J= 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 4.28 (s, 2H), 3.67 (d, J = 11.8Hz,2H), 3.37 (d, 2H), 3.06 (d, J = 4.9Hz, 3H), 1.91 (d, J = 6.3Hz, 2H), 1.75 (d, J = 7.4Hz, 2H), 1.44 (s, 9H).

[0320] Step 4: In a pressure vessel, 1,1,1,3,3,3-hexafluoro-2-propanol (0.7 mL, 30 equivalents) was added to 0.120 g (0.22 mmol, 1.0 equivalent) of tert-butyl 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate (3.2.1) and heated in a microwave oven at 150 °C for 2.5 h. The solvent was evaporated to dryness and ground with Et2O to give 0.080 g (82% yield) of the title compound. LCMS: ESI(+)[M+H] + =444.05. 1 H NMR (300MHz, DMSO- d 6) δ: 8.83 (d, J =2.3Hz, 1H), 8.72 (d, J = 2.2Hz, 1H), 8.52 - 8.44 (m, 2H), 8.13 (s, 1H), 7.85(d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 3.61 - 3.46 (m, 4H), 3.29 (s,3H), 3.06 (m, 3H), 1.70 (dd, J = 9.8, 6.7Hz, 4H).

[0321] Intermediate M: 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridine-3- [1,3,4-thiadiazole-2-yl]cyclohexane-1-carboxylate

[0322]

[0323] Step 1: Add DIPEA (149.53 mmol, 26 mL, 3.0 equivalent) and HATU (22.74 g, 59.81 mmol, 1.2 equivalent) to a solution of 6-chloro-4-(methylamino)pyridine-3-carbonylhydrazine (10.0 g, 49.84 mmol, 1.0 equivalent) and 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid (11.63 g, 54.83 mmol, 1.1 equivalent) in DMF (175 mL, 0.285 M). Stir the mixture at 25 °C for 2 hours. Quench the reaction mixture with a water / ice mixture (600 mL) and extract with EtOAc. Wash the combined organic layers with aqueous NaHCO3, aqueous KHSO4, water, and brine, and dry with Na2SO4. After evaporation, the crude product was purified by column chromatography (DCM / MeOH) to obtain methyl 4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazinoyl}bicyclo-[2.2.2]octane-1-carboxylate (15.6 g, 79% yield), which appeared as a white solid. LCMS: ESI(+)[M+H] + = 395.62. 1 H NMR (300MHz, DMSO- d 6), δ: 10.23 (1 H, s), 9.48 (1 H,s), 8.35 (1 H, s), 8.14 (1 H, br. q, J 5.1), 6.66 (1 H, s), 3.59 (3 H, s), 2.82 (3 H, d, J 4.9), 1.76 (12 H, m).

[0324] Step 2: Under argon atmosphere, methyl 4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazine carbonyl}bicyclo-[2.2.2]octane-1-carboxylate (5.0 g, 12.66 mmol, 1 equivalent) was dissolved in THF (250 mL, 0.05 M). The solution was warmed to 40 °C, and P2S5 (4.22 g, 18.99 mmol, 1.5 equivalent) was added in portions while stirring vigorously. The resulting suspension was then stirred under reflux for 2 hours (control by UPLC). After completion, the evaporation was evaporated. The residue was dissolved in DCM and washed with saturated K2CO3 solution. The aqueous layer was removed using a separatory funnel, and the organic layer was dried over Na2SO4 and concentrated under reduced pressure. The crude residue was purified by FC (DCM / EA) to give 4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexane-1-carboxylate (2.66 g, 53% yield). LCMS: ESI(+)[M+H]+ = 393.4. 1 H NMR (300MHz, DMSO-) d 6), δ: 8.66 (1 H, br. q, J 5.2), 8.38 (1 H, s), 6.82 (1 H, s), 3.61 (3 H, s), 2.97 (3 H, d, J 4.9), 2.05 - 1.94 (6 H,m), 1.94 - 1.82 (6 H,m).

[0325] Step 3: Add methyl cyclohexane-1-carboxylate (4.04 g, 10.9 mmol, 1.0 equivalent), cesium acetate (5.2 g, 27.2 mmol, 2.5 equivalent), and Pd(dppf)Cl2 to the solution. In an argon flash flask containing a solution of DCM (1.74 g, 2.2 mmol, 0.2 equivalents) in THF (218 mL, 0.05 M), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (4.401 g, 16.35 mmol, 1.5 equivalents) was added. The mixture was stirred overnight at 85 °C. The mixture was filtered through a diatomaceous earth mat, concentrated under vacuum, redissolved in dichloromethane, and deposited onto silica gel. The obtained solid was purified by rapid chromatography (acetonitrile / DCM gradient from 0 to 10%) to give methyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]cyclohexane-1-carboxylate (2.9 g, 56% yield), a yellow crystalline solid. LCMS: ESI(+) [M+H] + = 474.60. 1 H NMR (300MHz, DMSO- d 6), δ: 8.83 (d, J = 2.2Hz, 1H), 8.72 (d, J = 2.2Hz, 1H), 8.62 (d, J = 6.0Hz, 2H), 8.22 - 8.12 (m, 1H), 7.87(d, J = 4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 3.62 (s, 3H), 3.19 (s, 1H), 3.08(d, J = 4.9Hz, 3H), 2.42 (d, J = 11.7Hz, 1H), 2.19 (d, J = 10.3Hz, 2H), 2.03(d, J = 10.7Hz, 2H), 1.59 (q, J = 12.3, 11.2Hz, 4H).

[0326] Step 4: Methyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]cyclohexane-1-carboxylate (2.9 g, 6.1 mmol, 1.0 equivalent) was added to a solution of anhydrous pyridine (61.2 mL, 0.1 M) with lithium iodide (8.3 g, 61.2 mmol, 10 equivalent), and the resulting mixture was stirred at 150 °C until complete (using UPLC control, 24-48 h). The resulting mixture was then acidified with an equimolar amount of dilute HCl. The obtained solid was purified by column chromatography (0-20% gradient 2-propanol / DCM) to give the target compound (3.1 g, 95% yield) as a yellow solid. LCMS: ESI(+)[M+H] + = 460.23. 1 H NMR (300MHz, DMSO- d 6 ), δ:12.17 (s, 1H), 9.59 (d, J = 4.2Hz, 1H), 8.99 (d, J = 2.0Hz, 1H), 8.86 (d, J =2.0Hz, 1H), 8.69 (s, 1H), 8.15 (d, J = 4.9Hz, 1H), 7.95 (s, 1H), 7.24 (d, J =5.0Hz, 1H), 3.32 (m, 1H), 3.22 (d, J = 4.8Hz, 3H), 2.40 - 2.28 (m, 1H), 2.21(d, J = 11.8Hz, 2H), 2.04 (s, 2H), 1.72 - 1.46 (m, 4H).

[0327] Intermediate N: 7-[4-(methylamino)-5-{5-[(1r,4r)-4-formylcyclohexyl]-1,3,4-thiadiazole-2- [pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0328]

[0329] Step 1: At -5°C, 40% wt% methylamine (208 mL, 2403 mmol, 5.0 equivalent) was slowly added to a solution of methyl 4,6-dichloronicotinate (99.0 g, 481 mmol, 1.0 equivalent) in acetonitrile (990 mL, 0.49 M). The mixture was stirred at 0°C for 30 min, then at 25°C for 2 h. The reaction mixture was concentrated under reduced pressure and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography (hexane / EtOAc, 0 to 50%) to give methyl 6-chloro-4-(methylamino)pyridine-3-carboxylate (65.3 g, 68% yield) as a white solid. LCMS: ESI(+)[M+H] + = 202.2. 1 H NMR (300MHz, DMSO- d 6) δ: 8.50 (s, 1H), 8.04 (d, J = 5.5Hz, 1H), 6.74 (s, 1H), 3.83 (3 H, s), 2.88 (d, J = 5.0Hz, 3H).

[0330] Step 2: Hydrazine hydrate (129 ml, 1.68 mol, 8.0 equivalents) was added to a solution of methyl 6-chloro-4-(methylamino)pyridine-3-carboxylate (43 g, 0.21 mol, 1 equivalent) in EtOH (358 ml, 0.6 M), and the resulting mixture was stirred at 80 °C for 4 hours (UPLC control). The reaction mixture was then cooled to room temperature and extracted multiple times with DCM. The combined organic layers were dried over Na₂SO₄ and the solvent was concentrated under vacuum to give 6-chloro-4-(methylamino)pyridine-3-carbazide (34.4 g, 79% yield) as a white crystalline solid. LCMS: ESI(+)[M+H] + = 200.95. 1 H NMR (300MHz, DMSO- d 6 ) δ:9.81 (s, 1H), 8.21 (s, 1H), 8.11 (s, 1H), 6.62 (s, 1H), 4.46 (s, 2H), 2.82(d, J = 5.0Hz, 3H).

[0331] Step 3: Add DIPEA (179.43 mmol, 32 mL, 3.0 equivalent) and HATU (27.29 g, 71.77 mmol, 1.2 equivalent) to a solution of 6-chloro-4-(methylamino)pyridine-3-carbazide (12.0 g, 59.81 mmol, 1.0 equivalent) and trans-1,4-cyclohexanedicarboxylic acid monomethyl ester (12.25 g, 65.79 mmol, 1.1 equivalent) in DMF (150 mL). Stir the mixture at 25 °C for 1 hour, then quench with water, add brine, and extract with EtOAc. Wash the combined organic layers with brine, dry with Na₂SO₄, and concentrate under vacuum. The residue was purified by column chromatography with elution of DCM / MeOH (0-10%) to give methyl (1r,4r)-4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazinoyl}cyclohexane-1-carboxylate (15.5 g, 70% yield). LCMS: ESI(+)[M+H] + = 367.46. 1 H NMR (300MHz, DMSO- d 6) δ: 10.31 (s, 1H), 9.81 (s, 1H), 8.34 (s, 1H), 8.12 (q, J = 4.9Hz, 1H), 6.66 (s, 1H), 3.60 (s, 3H), 3.33 (s, 2H), 2.82 (d, J = 4.9Hz, 3H), 2.40 - 2.16 (m, 2H), 2.02 - 1.91 (m,2H), 1.82 (t, J = 7.2Hz, 2H), 1.55 - 1.25 (m, 4H).

[0332] Step 4: At 20°C, methyl (11.35 g, 30.77 mmol, 1 equivalent) of (1r,4r)-4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazine carbonyl}cyclohexane-1-carboxylate was added to a solution of phosphorus pentasulfide (8.9 g, 40.01 mmol, 1.3 equivalent) in anhydrous THF (1000 mL, 0.03 M). The resulting mixture was aged at 50°C for 3 hours. The reaction mixture was filtered, washed with THF, and concentrated under reduced pressure. The residue was purified by column chromatography (hexane / EA) to give methyl (1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexane-1-carboxylate (4.46 g, 40%). LCMS: ESI(+) [M+H] += 367.48. 1 H NMR (300MHz, DMSO- d 6) δ: 8.65 (d, J = 5.2Hz, 1H),8.39 (s, 1H), 6.82 (s, 1H), 3.62 (s, 3H), 3.21 (td, J = 11.4Hz, 3.5Hz, 1H), 2.98 (d, J = 4.9Hz, 3H), 2.48 - 2.37 (m, 1H), 2.22 - 1.96 (m, 4H), 1.72 -1.45 (m, 4H).

[0333] Step 5: Under an argon atmosphere, a solution of (1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexane-1-carboxylate (4.26 g, 11.61 mmol, 1 equivalent) in anhydrous THF (180.0 mL, 0.06 M) was cooled to -15 °C and treated with DIBAL-H (35 mL of 1.0 M THF solution, 34.8 mmol, 3.0 equivalent). After 30 minutes, the cooling bath was removed, and the mixture was warmed to room temperature and stirred for 1 hour. Subsequently, the reactants were quenched by adding MeOH (30 mL), stirred vigorously for 20 minutes, followed by the addition of a saturated aqueous solution of Rochelle salt. The resulting mixture was extracted with DCM. The combined organic layers were washed with dilute KHSO4, water, and brine, dried over Na2SO4, and concentrated under reduced pressure. The residue was purified by column chromatography (DCM / ACN) to give [(1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexyl]methanol (3.0 g, 8.85 mmol, 1.0 equivalent) and 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (3.19 g, 81% yield). LCMS: ESI(+)[M+H] + = 339.48. 1 HNMR (300MHz, DMSO- d 6) δ: 8.66 (d, J = 4.6Hz, 1H), 8.38 (s, 1H), 6.82 (s, 1H), 4.46 (t, J = 5.3Hz, 1H), 3.26 (t, J = 5.8Hz, 2H), 3.14 (tt,J = 11.9Hz, 3.6Hz, 1H), 2.97 (d, J = 4.9Hz, 3H), 2.22 - 2.10 (m, 2H), 1.92 - 1.80 (m,2H), 1.64 - 1.36 (m, 3H), 1.26 - 1.00 (m, 2H).

[0334] Step 6: Add [(1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexyl]methanol (3.0 g, 8.85 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (3.4 g, 12.4 mmol, 1.4 equivalent) and Pd(dppf)Cl2 CH2Cl2 (1.82 g, 2.21 mmol, 0.25 equivalence) was added to a solution of anhydrous dioxane (130 mL, 0.07 M) with 2 M K2CO3 aqueous solution (9 mL, 17.71 mmol, 2.0 equivalence). The mixture was degassed with argon for 30 min and then stirred at 120 °C for 25 h. The reactants were diluted with DCM, filtered through a diatomaceous earth mat, washed with DCM / MeOH (1:1), and concentrated under vacuum. The residues were purified twice by column chromatography (DCM / ACN and DCM / IPA, respectively) to give 7-[4-(methylamino)-5-{5-[(1r,4r)-4-(hydroxymethyl)cyclohexyl]-1,3,4-thiadiazol-2-yl}pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (2.35 g, 60% yield). LCMS: ESI(+)[M+H] + = 446.38. 1 H NMR (300MHz, DMSO- d 6) δ: 8.84 (d, J = 2.2Hz, 1H), 8.73 (d, J = 2.2Hz, 1H), 8.64 (d, J = 9.7Hz, 2H), 8.17 (s, 1H), 7.87 (d, J =4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 4.47 (t, J = 5.3Hz, 1H), 3.27 (t, J=5.8Hz, 2H), 3.22 - 3.11 (m, 1H), 3.09 (d, J = 4.9Hz, 3H), 2.23 - 2.13 (m,2H), 1.93 - 1.83 (m, 2H), 1.66 - 1.39 (m, 3H), 1.26 - 1.00 (m, 4H).

[0335] Step 7: Add Dys-Martin periodide (2.91 g, 6.86 mmol, 1.3 equivalent) to a solution of 7-[4-(methylamino)-5-{5-[(1r,4r)-4-(hydroxymethyl)cyclohexyl]-1,3,4-thiadiazol-2-yl}pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxynitrile (2.35 g, 5.27 mmol, 1 equivalent) in DCM (1.3 L, 0.004 M). Stir the mixture overnight at room temperature. Quench the reaction mixture with 20% aqueous Na2S2O3 and saturated NaHCO3 aqueous solution and stir until the aqueous layer becomes clear. Extract the latter with DCM. Dry the combined organic layers with Na2SO4 and concentrate under vacuum. Purify the residue by grinding with DCM / Et2O (1:1) to give the title compound (1.83 g, 78% yield). LCMS: ESI(+)[M+H] + =444.22. 1 H NMR (300MHz, DMSO-) d 6) δ: 9.63 (br. d, J = 1.1Hz, 1H), 8.84 (d, J = 2.3Hz, 1H), 8.74 (d, J = 2.2Hz, 1H), 8.66 (s, 1H), 8.65 (q, J = 2.7Hz, 1H), 8.17 (s, 1H), 7.88 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 3.19 (ddt, J = 11.7Hz,7.0Hz, 3.6Hz, 1H), 3.09 (d, J = 4.9Hz, 3H), 2.41 (ddt, J= 12.2Hz, 7.3Hz, 3.7Hz, 1H), 2.29 - 2.18 (m, 2H), 2.14 - 2.02 (m, 2H), 1.75 - 1.55 (m, 2H), 1.51 - 1.31 (m, 2H).

[0336] Intermediate O: 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridine-3- [1,3,4-thiadiazol-2-yl]cyclohexane-1-carboxylic acid

[0337]

[0338] Step 1: Add methyl cyclohexane-1-carboxylate (4 g, 10.9 mmol, 1 equivalent), CsOAc (5.3 g, 27.3 mmol, 2.5 equivalent), and Pd(dppf)Cl2 to the solution containing methyl cyclohexane-1-carboxylate (4 g, 10.9 mmol, 1 equivalent), CsOAc (5.3 g, 27.3 mmol, 2.5 equivalent), and Pd(dppf)Cl2. Argon-purged flasks containing DCM (1.74 g, 2.18 mmol, 0.2 equivalents) and THF (218 mL, 0.05 M) solution were supplemented with 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (4.4 g, 16.35 mmol, 1.5 equivalents). The mixture was stirred overnight at 85 °C. The reactants were filtered, concentrated under vacuum, dissolved in DCM, and adsorbed onto silica gel. The solid was purified by rapid chromatography (0 to 10% ACN / DCM) to give the desired compound as a yellow crystalline solid (2.9 g, 56% yield). LCMS: ESI(+)[M+H] + = 474.60. 1 H NMR (300MHz, DMSO- d 6), δ: 8.83(d, J = 2.2Hz, 1H), 8.72 (d, J = 2.2Hz, 1H), 8.62 (d, J = 6.0Hz, 2H), 8.22 -8.12 (m, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 3.62 (s, 3H), 3.19 (s, 1H), 3.08 (d, J = 4.9Hz, 3H), 2.42 (d, J = 11.7Hz, 1H), 2.19 (d, J=10.3Hz, 2H), 2.03 (d, J = 10.7Hz, 2H), 1.59 (q, J = 12.3, 11.2Hz, 4H).

[0339] Step 2: Methyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]cyclohexane-1-carboxylate (2.9 g, 6.12 mmol, 1 equivalent) was added to a solution of anhydrous pyridine (61 mL, 0.1 M) with lithium iodide (8.27 g, 61.18 mmol, 10 equivalents), and the resulting mixture was stirred at 150 °C for 24 h. The resulting mixture was acidified with an equimolar amount of dilute HCl. The obtained solid was filtered off and purified by rapid chromatography (0 to 20% 2-propanol / DCM) to give the desired compound as a yellow solid (2.5 g, 89% yield). LCMS: ESI(+)[M+H] + =460.23. 1 H NMR (300MHz, DMSO- d 6), δ: 12.17 (s, 1H), 9.59 (d, J = 4.2Hz, 1H), 8.99 (d, J = 2.0Hz, 1H), 8.86 (d, J = 2.0Hz, 1H), 8.69 (s, 1H), 8.15 (d, J = 4.9Hz, 1H), 7.95 (s, 1H), 7.24 (d, J = 5.0Hz, 1H), 3.32 (m, 1H), 3.22 (d, J = 4.8Hz, 3H), 2.40 - 2.28 (m, 1H), 2.21 (d, J = 11.8Hz, 2H), 2.04 (s, 2H), 1.72 - 1.46 (m, 4H).

[0340] Intermediate P: 7-[4-(methylamino)-5-{5-[(1r,4r)-4-(ethylamino)cyclohexyl]-1,3,4-thiadi] [Azol-2-yl]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0341]

[0342] Step 1: Add NaH (0.357 g, 9.32 mmol, 1.2 equivalents) to a solution of methyl trans-4-(tert-butoxycarbonylamino)cyclohexanecarboxylate (2.0 g, 7.8 mmol, 1.0 equivalents) cooled to 0 °C in DMF (25 mL, 0.46 M), and stir the resulting mixture at 0 °C for 30 min. Then, add ethyl iodine (0.937 mL, 11.66 mmol, 1.5 equivalents), and stir the reaction mixture overnight at room temperature. The DMF is then removed by azeotropic evaporation with PhMe (3 × 100 mL). Add 50 mL of saturated NH4Cl aqueous solution to the remaining solid. Transfer the resulting mixture to a separatory funnel and extract with Et2O (4 × 50 mL). Dry the combined organic layers with Na2SO4 and concentrate under vacuum. The crude product was purified by column chromatography (hexane / EtOAc, gradient 0% to 20%) to obtain methyl (1r,4r)-4-{[(tert-butoxy)carbonyl](ethyl)amino}cyclohexane-1-carboxylate (1.883 g, 85% yield), which was a pale yellow viscous oil. 1 H NMR (300MHz, DMSO- d 6 ) δ 3.63 (s, 3H), 3.07 (q, J = 7.1Hz, 2H), 2.26 (t, J = 11.9Hz, 1H), 1.94 (d, J = 12.5Hz, 2H), 1.55 (d, J = 27.9Hz, 4H), 1.39 (d, J = 1.7Hz, 12H), 1.02 (t, J = 6.8Hz, 3H).

[0343] Step 2: Add LiOH to a solution of methyl (1r,4r)-4-{[(tert-butoxy)carbonyl](ethyl)amino}cyclohexane-1-carboxylate (1.88 g, 6.6 mmol, 1.0 equivalent) in a mixture of THF (15 mL, 0.44 M) and water (3.0 mL, 2.41 M). H₂O (0.57 g, 13.2 mmol, 2.0 equivalence) was added, and the reaction mixture was stirred overnight at room temperature. After NMR showed complete consumption of the substrate, THF was removed under vacuum, and the resulting aqueous solution was acidified to pH 5 with 10 wt% NaHSO₄ solution. The resulting suspension was then extracted with EtOAc (4 × 25 mL). The combined organic layers were dried over Na₂SO₄ and concentrated under vacuum to give (1r,4r)-4-{[(tert-butoxy)carbonyl](ethyl)amino}cyclohexane-1-carboxylic acid (1.566 g, 87% yield) as a white solid. 1 H NMR (300MHz, DMSO- d 6) δ 12.08 (s, 1H), 3.07 (d, J = 7.3Hz, 2H), 2.13(tt, J = 11.9, 3.4Hz, 1H), 1.93 (dt, J = 9.2, 2.8Hz, 2H), 1.52 (dd, J = 28.7,16.5Hz, 4H), 1.39 (s, 9H), 1.33 (dd, J = 12.4, 3.8Hz, 1H), 1.02 (t, J =6.8Hz, 3H).

[0344] Step 3: Add DIPEA (3.0 mL, 17.3 mmol, 3.00 equivalent) and HATU (3.29 g, 8.65 mmol, 1.5 equivalent) to a solution of (1r,4r)-4-{[(tert-butoxy)carbonyl](ethyl)amino}cyclohexane-1-carboxylic acid (1.57 g, 5.77 mmol, 1.00 equivalent) in anhydrous DMF (15 mL, 0.38 M). Stir the mixture at 25 °C for 30 min, and add 6-chloro-4-(methylamino)pyridine-3-carbonylhydrazine (1.216 g, 6.06 mmol, 1.05 equivalent). After 2 hours at room temperature, quench the reaction mixture with brine and extract with EtOAc (5 × 50 mL). Dry the combined organic layers with Na₂SO₄ and concentrate under vacuum. The crude product was purified by column chromatography (DCM / MeOH, gradient 0 to 3%) to obtain the desired product as a light brown solid (1.87 g, 71% yield). LCMS: ESI(+)[M+H] + =454.4. 1 H NMR (300MHz, DMSO- d6) δ 10.31 (s, 1H), 9.82 (s,1H), 8.35 (s, 1H), 8.12 (d, J = 5.3Hz, 1H), 6.67 (s, 1H), 3.13 - 3.06 (m,2H), 2.83 (d, J = 4.9Hz, 3H), 2.23 (dd, J = 14.7, 4.0Hz, 1H), 1.85 (d, J =11.3Hz, 2H), 1.69 - 1.46 (m, 5H), 1.41 (s, 9H), 1.04 (t, J = 6.8Hz, 3H).

[0345] Step 4: Add Lawson's reagent (1.83 g, 4.52 mmol, 1.1 equivalent) to a solution of N-ethyl-N-[(1r,4r)-4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazinoyl}cyclohexyl]tert-butyl carbamate (1.87 g, 4.11 mmol, 1.0 equivalent) in anhydrous THF (100 mL, 0.04 M). Stir the reaction mixture at 90 °C for 2 hours. Remove volatiles under vacuum, and dissolve the residue in 50 mL of DCM, washing with a saturated aqueous solution of NaHCO3. Extract the aqueous phase with DCM (3 × 50 mL). Combine the organic layers, dry over Na2SO4, and concentrate under vacuum. The crude product was purified by dual-column chromatography (DCM / MeOH, gradient 0 to 4% and hexane / EtOAc, gradient 0 to 40%) to give N-ethyl-N-[(1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexyl]tert-butyl carbamate (0.794 g, 43% yield) as a white, foamy solid. LCMS: ESI(+)[M+H] + =452.5. 1 H NMR (300MHz, DMSO- d 6) δ 8.66 (d, J = 5.9Hz, 1H), 8.39 (d, J = 1.6Hz, 1H), 6.82 (d, J = 1.7Hz, 1H), 3.16 (t, J = 12.0Hz, 3H), 2.98 (d, J = 4.9Hz, 3H), 2.24 - 2.14 (m, 2H), 1.69 (d,J = 20.3Hz, 7H), 1.41 (d, J = 2.0Hz, 9H), 1.12 - 1.01 (m, 3H).

[0346] Step 5: Add N-ethyl-N-[(1r,4r)-4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}cyclohexyl] tert-butyl carbamate (0.794 g, 1.76 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.662 g, 2.46 mmol, 1.4 equivalent), and Pd(dppf)Cl2 A suspension of CH2Cl2 (0.36 g, 0.44 mmol, 0.25 equivalents) and K2CO3 (0.485 g, 3.5 mmol, 2.0 equivalents) in anhydrous dioxane (25 mL, 0.07 M) was degassed with argon for 2-3 minutes and stirred overnight at 120 °C. After complete conversion of the starting material, the reactants were diluted with MeOH, filtered through a diatomaceous earth mat, and concentrated under vacuum. The crude product was purified by FC (DCM / ACN, gradient 0 to 40%) to give N-ethyl-N-[(1r,4r)-4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]cyclohexyl]tert-butyl carbamate (0.676 g, 69% yield) as a yellow solid. LCMS: ESI(+)[M+H] + =559.85. 1 H NMR (300MHz, DMSO- d 6) δ 8.85 (d, J = 2.2Hz, 1H), 8.74 (d, J = 2.3Hz, 1H), 8.67 (s, 1H), 8.63 (d, J = 5.0Hz,1H), 8.19 (s, 1H), 7.88 (d, J = 4.8Hz, 1H), 7.13 (d, J = 4.8Hz, 1H), 3.26 -3.12 (m, 3H), 3.09 (d, J = 4.9Hz, 3H), 2.21 (d, J= 11.2Hz, 2H), 1.83 - 1.57 (m, 6H), 1.42 (s, 9H), 1.12 - 1.02 (m, 3H).

[0347] Step 6: N-ethyl-N-[(1r,4r)-4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]cyclohexyl]tert-butyl carbamate (0.676 g, 1.21 mmol, 1.0 equivalent) was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (3.185 mL, 25 equivalent) and stirred at 150 °C for 8 hours. After the starting material was completely consumed, the reaction mixture was co-evaporated with DCM several times to remove trace amounts of HFIP. The crude product was purified by column chromatography (DCM / MeOH, gradient 0 to 30%) to give the title compound (0.350 g, 63% yield) as a deep yellow solid. LCMS: ESI(+)[M+H] + =459.03. 1 H NMR (300MHz, DMSO- d 6 ) δ 8.84 (s, 1H), 8.74 (s,1H), 8.65 (s, 2H), 8.17 (d, J = 3.1Hz, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.7Hz, 1H), 4.10 (s, 1H), 3.17 (s, 2H), 3.09 (d, J = 4.7Hz, 3H), 2.71 -2.56 (m, 3H), 2.16 (d, J = 12.8Hz, 2H), 2.04 (t, J = 11.7Hz, 2H), 1.60 (q, J = 12.4Hz, 3H), 1.32 - 1.13 (m, 5H), 1.04 (t, J = 6.8Hz, 3H), 0.82 - 0.71 (m,1H).

[0348] Intermediate Q: 7-[5-(5-{3,9-diazaspiro[5.5]undecane-3-yl}-1,3,4-thiadiazol-2-yl)-4- (oxane-4-ylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0349]

[0350] Synthesized according to the same procedure as shown for intermediate T, except that tert-butyl 3,9-diazaspiro[5.5]undecane-3-carboxylate was used as the starting material instead of tert-butyl 4,7-diazaspiro[2.5]octane-4-carboxylate. LCMS C 29 H 33 N9OS theoretical value: 555.3, measured value: m / z = 556.3 [M+H] + .

[0351] Intermediate R: 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4- [(propyl-2-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0352]

[0353] The title compound was synthesized according to the same procedure as described for intermediate L, except that 7-{5-bromo-4-[(prop-2-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile was used instead of 7-[5-bromo-4-(methylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazin-3-carboxylonitrile as the starting material. LCMS: ESI(+)[M+H] + = 472.20. 1 H NMR (300MHz, DMSO-) d 6 ) δ: 8.82 (d, J = 2.2Hz, 1H), 8.71 (d, J = 2.2Hz, 1H), 8.56(d, J = 7.1Hz, 1H), 8.46 (s, 1H), 8.18 (s, 1H), 7.83 (d, J = 4.8Hz, 1H), 7.11(d, J = 4.8Hz, 1H), 3.91 (h, J = 6.5Hz, 1H), 3.60 - 3.44 (m, 4H), 3.32 - 3.24(m, 3H), 1.69 (dd, J = 10.0, 6.9Hz, 4H), 1.34 (d, J = 6.3Hz, 6H).

[0354] Intermediate S: 7-(4-((4,4-difluorocyclohexyl)amino)-5-(5-(piperazin-1-yl)-1,3,4-thiadiazole-2- (1,2-b)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0355]

[0356] Step 1: Under N2, add K3PO4 (2.00M, 20.6mL, 2.00 equivalent) and Pd(dppf)Cl2 to a solution of 2-bromo-N-(4,4-difluorocyclohexyl)pyridine-4-amine (6.00g, 20.6mmol, 1.00 equivalent) and 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (6.66g, 24.7mmol, 1.20 equivalent) in DME (60.0mL). CH2Cl2 (1.68 g, 2.06 mmol, 0.10 equivalents) was used to stir the mixture at 100 °C for 2 hours under N2. The reaction mixture was poured into water (50.0 mL), filtered, washed with ethyl acetate (100 mL × 4), and the filter cake (4.0 g) was collected and concentrated under vacuum. The filtrate was extracted with ethyl acetate (100 mL × 3) and then concentrated under vacuum to give a residue (2.00 g). The residue (2.00 g) was subjected to column chromatography (SiO2, petroleum ether / ethyl acetate = 1 / 1 and dichloromethane / methanol = 20 / 1, R... f Purification was performed using a concentration of 0.20 g / mL. The product separated by column chromatography was combined with the filtered product to give the desired product as a yellow solid (5.00 g, 14.1 mmol, 68.6% yield). LCMS: m / z = 354.3 (M+H) + .

[0357] Step 2: At 0 °C, a solution of NBS (2.49 g, 14.0 mmol, 0.90 equivalent) in MeCN (45.0 mL) and DCM (45.0 mL) was added to a solution of 7-(4-((4,4-difluorocyclohexyl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (5.50 g, 15.5 mmol, 1.00 equivalent) in MeCN (230 mL) and DCM (230 mL). The mixture was stirred at 0 °C for 0.5 h. The reaction mixture was concentrated under vacuum. The crude product was milled at 25 °C with ethyl acetate (20.0 mL) for 30 min to give the desired product (6.00 g, 13.8 mmol, 89.1% yield) as a yellow solid, which was confirmed by LCMS. LCMS: m / z = 432.2 (M+H) + .

[0358] Step 3: Under N2, KOAc (326 mg, 3.33 mmol, 3.00 equivalent) and Pd(PPh3)2Cl2 (116 mg, 166 µmol, 0.15 equivalent) were added to a solution of 7-(5-bromo-4-((4,4-difluorocyclohexyl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (480 mg, 1.11 mmol, 1.00 equivalent) and 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bis(1,3,2-dioxane-pentaborane) (563 mg, 2.22 mmol, 2.00 equivalent) in dioxane (10.0 mL) and DMF (5.00 mL). The mixture was then stirred at 80 °C for 2 hours. The coarse material was filtered, and the filtrate was concentrated under vacuum. The residue was purified by preparative HPLC (FA conditions) and then concentrated by freeze-drying to give the desired product as a yellow solid (1.40 g, 2.87 mmol, 23.5% yield). LCMS: m / z = 398.2 (M+H) + .

[0359] Step 4: Under N2, add XPhos Pd G3 (121 mg, 143 µmol, 0.10 equivalent) and K3PO4 (2.00 M, 1.79 mL, 2.50 equivalent) to a solution of (6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-((4,4-difluorocyclohexyl)amino)pyridin-3-yl)boronic acid (700 mg, 1.43 mmol, 1.00 equivalent, FA) and 4-(5-bromo-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (525 mg, 1.51 mmol, 1.05 equivalent) in DME (15.0 mL). Stir the mixture under N2 at 100 °C for 1 hour. The reactants were poured into water (20.0 mL), filtered, and washed with ethyl acetate (10.0 mL × 4). The filtrate was extracted with ethyl acetate (20.0 mL × 3), and then concentrated under vacuum to obtain the residue. The residue, confirmed by HPLC and purified by preparative HPLC, was then concentrated by freeze-drying to give the desired product as a yellow solid (600 mg, 965 µmol, 33.6% yield). LCMS: m / z = 622.2 (M+H) + .

[0360] Step 5: Add HCl / EtOAc (4M, 2.57 mL, 10.6 equivalents) to a solution of 4-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-((4,4-difluorocyclohexyl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (600 mg, 965 µmol, 1.00 equivalents) in EtOAc (2.00 mL), and then stir the mixture at 25 °C for 15 minutes. Concentrate the mixture under vacuum. The crude product was ground with ethyl acetate (1.00 mL) at 25 °C for 15 minutes, then filtered, and the filter cake was concentrated under vacuum to give a yellow solid, 7-(4-((4,4-difluorocyclohexyl)amino)-5-(5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl)pyridin-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (310 mg, 511 µmol, 52.9% yield, HCl), which was confirmed by LCMS. LCMS: m / z = 522.1 (M+H) + . 1 H NMR: 400MHz, DMSO- d 6 δ 9.78 (d, J = 7.2Hz, 1H), 9.57 (s, 2H), 9.01 (d, J = 2.0Hz, 1H), 8.92 (d, J = 2.0Hz, 1H), 8.55 (s, 1H), 8.30 (d, J = 5.2Hz, 1H), 8.16 (s, 1H), 7.26 (d, J = 4.8Hz, 1H), 4.24 - 4.17 (m, 2H), 3.72 - 3.69 (m, 5H), 3.23 (s, 2H), 2.17 - 2.10 (m, 6H), 1.76 - 1.73 (m, 2H).

[0361] Intermediate T: 7-[5-(5-{4,7-diazaspiro[2.5]oct-7-yl}-1,3,4-thiadiazol-2-yl)-4-(isopropyl) [[1,2-b]pyridin-3-carboxynitrile]pyrrolo[1,2-b]pyridazine-3-carboxynitrile

[0362]

[0363] Step 1: Dibromothiadiazole (500 mg, 2.05 mmol) and tert-butyl 4,7-diazaspiro[2.5]octane-4-carboxylate (435 mg, 1 equivalent) were dissolved in DIEA (0.6 mL, 1.75 equivalent) and dioxane (0.15 M), and then heated to 110 °C in a sealed vial. The reaction mixture was stirred for 1.5 h, then cooled and concentrated on silica gel. Silica gel column chromatography (0-5% methanol / DCM) yielded the desired product (0.105 g, 14%). LCMS C 13 H 19 Theoretical value of N4BrO2S: 374.0, measured value: m / z = 320.9 [M-tert-butyl] + .

[0364] Step 2: 6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(isopropylamino)pyridin-3-ylboronic acid (90 mg, 0.28 mmol), cesium carbonate (0.2 g, 2.2 equivalents), XantPhos (0.06 g, 0.4 equivalents), palladium acetate (13 mg, 0.2 equivalents), and 7-(5-bromo-1,3,4-thiadiazol-2-yl)-4,7-diazaspiro[2.5]octane-4-carboxylic acid tert-butyl ester (105 mg, 1 equivalent) were combined in a microwave-safe vial, followed by the addition of dioxane (8 mL). The reaction mixture was then purged with nitrogen for 1 min and stirred in a microwave reactor at 145 °C for 30 min. The reaction mixture was then filtered through diatomaceous earth and concentrated on silica gel. Chromatography (0-10% methanol / DCM) provided the desired intermediate. The substance was dissolved in DCM:TFA (DCM to TFA ratio of 5:1, 0.1M) at room temperature and stirred for 3 hours. The reactants were concentrated and purified by reversed-phase chromatography on a C18 column (0-100% ACN / water, 0.1% TFA), followed by lyophilization overnight to give the desired product (28 mg, 21% yield).

[0365] LCMS C 24 H 25 Theoretical value for N9S: 471.2, Measured value: m / z = 472.3 [M+H] + .

[0366] Intermediate U: [5-(5-{4-formylbicyclo[2.2.2]octane-1-yl}-1,3,4-thiadiazol-2-yl)-4-(methyl [[1,2-b]pyridin-3-carboxynitrile]pyrrolo[1,2-b]pyridazine-3-carboxynitrile

[0367]

[0368] Step 1: A solution of methyl 4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}bicyclo[2.2.2]octane-1-carboxylate (3.8 g, 9.67 mmol, 1 equivalent) in anhydrous THF (270 mL, 0.036 M) was cooled to -15 °C under an argon atmosphere and treated with DIBAL-H (29 mL, 1.0 M THF solution, 29.02 mmol, 3 equivalent). After 30 minutes, the cooling bath was removed, and the reaction mixture was warmed to room temperature and stirred for 1 hour. The mixture was then quenched by adding MeOH (30 mL) and stirred vigorously for 20 minutes, followed by the addition of a saturated aqueous solution of Rochelle salt. The resulting mixture was extracted with DCM, and the combined organic layers were washed with a saturated NH4Cl solution, dried over Na2SO4, and concentrated under reduced pressure. The crude product was purified by column chromatography (eluting with DCM / ACN) to give 3.25 g of (4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}bicyclo[2.2.2]oct-1-yl)methanol (92% yield). LCMS: ESI(+)[M+H] + = 365.46. 1 H NMR (300MHz, DMSO-) d 6) δ: 8.68 (q, J = 5.2Hz, 1H), 8.38 (s, 1H), 6.81 (s, 1H), 4.46 (t, J = 5.4Hz, 1H), 3.10 (d, J = 5.0Hz, 2H), 2.97 (d, J = 4.9Hz, 3H), 2.00 - 1.89 (m, 6H), 1.56 - 1.45 (m, 6H).

[0369] Step 2: Add (4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}bicyclo[2.2.2]oct-1-yl)methanol (1.8 g, 4.93 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.59 g, 5.92 mmol, 1.2 equivalent) and Pd(dppf)Cl2 CH2Cl2 (1.01 g, 1.23 mmol, 0.25 equivalence) was added to a solution of anhydrous dioxane (125 mL, 0.04 M) with 2 M K2CO3 aqueous solution (5 mL, 9.87 mmol, 2.0 equivalence). The reaction mixture was degassed with argon for 30 min and then stirred at 120 °C for 25 h. The reaction mixture was diluted with DCM, filtered through a diatomaceous earth mat, washed with DCM / MeOH (1:1), and concentrated under reduced pressure. The crude product was purified twice by column chromatography (DCM / acetone and DCM / IPA) to give 7-(5-{5-[4-(hydroxymethyl)bicyclo[2.2.2]oct-1-yl]-1,3,4-thiadiazol-2-yl}-4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (1.46 g, 63% yield). LCMS: ESI(+)[M+H] + = 472.40. 1 H NMR (300MHz, DMSO- d 6) δ: 8.83 (d, J =2.2Hz, 1H), 8.72 (d, J = 2.3Hz, 1H), 8.65 (br. q, J = 4.9Hz, 1H), 8.63 (s,1H), 8.16 (s, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 4.46 (t, J = 5.4Hz, 1H), 3.11 (d, J = 5.4Hz, 2H), 3.07 (d, J = 4.8Hz, 3H), 2.01 - 1.90 (m, 6H), 1.57 - 1.46 (m, 6H).

[0370] Step 3: Add Dysmart periodide (1.71 g, 4.02 mmol, 1.3 equivalent) to a solution of 7-(5-{5-[4-(hydroxymethyl)bicyclo[2.2.2]oct-1-yl]-1,3,4-thiadiazol-2-yl}-4-(methylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile (1.46 g, 3.10 mmol, 1 equivalent) in DCM (900 mL, 3.44 mM). Stir the reaction mixture at room temperature for 2 hours, then quench with a 20% aqueous solution of Na₂S₂O₃ and a saturated aqueous solution of NaHCO₃. Stir the mixture until the aqueous layer becomes clear. Extract the aqueous layer with DCM. Wash the combined organic layers with a saturated NaHCO₃ solution, water, and brine. Dry the combined organic layers with Na₂SO₄ and concentrate under reduced pressure. The crude product was ground with Et₂O, filtered, and the filtered solid was washed with a mixture of DCM / Et₂O (1:1), Et₂O, and pentane to give the title compound (1.28 g, 88% yield). LCMS: ESI(+)[M+H] + =470.15. 1 H NMR (300MHz, DMSO- d 6) δ: 9.49 (s, 1H), 8.85 (d, J = 2.2Hz, 1H), 8.75 (d, J = 2.2Hz, 1H), 8.67 (s, 1H), 8.64 (q, J = 5.1Hz, 1H), 8.19 (s,1H), 7.88 (d, J = 4.8Hz, 1H), 7.13 (d, J = 4.8Hz, 1H), 3.09 (d, J = 4.9Hz,3H), 2.09 - 1.98 (m, 6H), 1.82 - 1.71 (m, 6H).

[0371] Intermediate V: 7-[4-(methylamino)-5-{5-[4-(piperidin-4-yl)piperazin-1-yl]-1,3,4-thiadiazole-2- [pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0372]

[0373] Synthesized according to the same procedure as shown for intermediate T, except that tert-butyl 4-piperazin-1-ylpiperidine-1-carboxylate was used instead of tert-butyl 4,7-diazaspiro[2,5]octane-4-carboxylate as the starting material. LCMS C 25 H 28 N 10Theoretical value of S: 500.2, measured value: m / z = 501.5 [M+H] + .

[0374] Intermediate W: 7-{4-[(3-methyloxetane-3-yl)amino]-5-[5-(piperazin-1-yl)-1,3,4-thia} [diazol-2-yl]pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylon

[0375]

[0376] Step 1: DIPEA (17.96 mL, 138.98 mmol, 3.5 equivalents) was added to 3-methyl-3-oxetanebutylamine-HCl (4.9 g, 39.7 mmol, 1 equivalent) in a stirred solution of DMF (39.7 mL, 1 M). Then, 2-chloro-4-fluoropyridine (7.4 mL, 79.4 mmol, 2 equivalents) was added, and the mixture was heated to 100 °C in a sealed tube for 32 hours. Excess reagents and DMF were removed by evaporation on a rotary evaporator. The residue (16.25 g) was diluted with DCM and adjusted to pH 8 with a saturated aqueous solution of NaHCO3. The layers were separated, and the organic layer was extracted four times with DCM. The combined organic layers were washed with brine, dried over Na2SO4, and concentrated on a rotary evaporator. The crude product was purified by FC (hexane / ethyl acetate) to give 5.17 g (54% yield) of 2-chloro-N-(3-methyloxetane-3-yl)pyridine-4-amine. [M+H] + = 199.50 m / z. 1 H NMR (300MHz, DMSO-d6) δ 7.86 (d, J = 5.8Hz, 1H), 7.41 (s, 1H), 6.36 - 6.25 (m, 2H), 4.60 (d, J = 6.1Hz, 2H), 4.51 (d, J = 6.2Hz, 2H), 1.56 (s, 3H).

[0377] Step 2: In a 400 ml glass reactor, 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (9.293 g, 34.532 mmol, 1.4 equivalents) and tripotassium phosphate (10.686 g, 49.335 mmol, 2.0 equivalents) were added to a solution of 2-chloro-N-(3-methyloxetane-3-yl)pyrrolidine-4-amine (5.904 g, 24.668 mmol, 1.0 equivalents) in dimethoxyethane (123.33 ml, 0.2 M). The mixture was degassed by evacuating the reactor and backfilling with argon (three times). Xphos Pd G3 (1.491 g, 1.726 mmol, 0.07 equivalents) was added and the evacuation-backfilling procedure was repeated three times. The reactor was sealed and the mixture was stirred overnight at 120°C. The mixture was diluted and concentrated with DCM. The residue was purified by silica gel FC (DCM / EA 100:0 to 0:100) to give 4.83 g (55% yield) of 7-{4-[(3-methyloxetane-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonite as a yellow solid. [M+H] + = 306.46 m / z. 1 H NMR (300MHz, DMSO-d6) δ 8.80 (d, J = 2.2Hz, 1H), 8.68 (d, J = 2.2Hz, 1H), 8.19 (d, J = 5.7Hz, 1H), 7.81 - 7.71 (m, 2H), 7.28(s, 1H), 7.09 (d, J = 4.8Hz, 1H), 6.29 (dd, J = 5.7, 2.3Hz, 1H), 4.69 (d, J =6.0Hz, 2H), 4.55 (d, J = 6.0Hz, 2H), 1.64 (s, 3H).

[0378] Step 3: At 0°C, a solution of N-bromosuccinimide (1.966 g, 11.046 mmol, 0.95 equivalents) in anhydrous acetonitrile (14.53 ml, 0.8 M) was added in a single addition to a solution of 7-{4-[(3-methyloxetane-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxynitrile (3.944 g, 11.625 mmol, 1.0 equivalents) in anhydrous acetonitrile (136.78 ml, 0.085 M) and anhydrous dimethylformamide (35.23 ml, 0.33 M). The mixture was stirred at 0°C for 45 minutes. The precipitate was filtered off and dried to give 7-{5-bromo-4-[(3-methyloxetane-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (2.1 g, 5.465 mmol, 47%). The filtrate was concentrated and purified by FC (silica gel, DCM and DCM / EA 7:3) to give an additional 1.57 g (35% yield) of 7-{5-bromo-4-[(3-methyloxetane-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile. [M+H] + = 386.26 m / z. 1 H NMR (300MHz, DMSO-d6) δ8.82 (d, J = 2.2Hz, 1H), 8.80 (d, J = 2.2Hz, 1H), 8.43 (s, 1H), 7.79 (d, J =4.8Hz, 1H), 7.64 (s, 1H), 7.09 (d, J = 4.8Hz, 1H), 6.78 (s, 1H), 4.79 (d, J =6.3Hz, 2H), 4.58 (d, J = 6.4Hz, 2H), 1.71 (s, 3H).

[0379] Step 4: In a glass pressure reactor, add tert-butyl 4-(1,3,4-thiadiazol-2-yl)piperazine-1-carboxylate (2.594 g, 9.499 mmol, 1.0 equivalent) to a solution of 7-{5-bromo-4-[(3-methyloxetane-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylon (3.65 g, 9.499 mmol, 1.0 equivalent) in anhydrous dioxane (279.39 ml, 0.034 M). Evacuate the reactor and backfill with argon three times. Palladium(II) acetate (0.213 g, 0.949 mmol, 0.1 equivalent), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthones (1.099 g, 1.899 mmol, 0.2 equivalent), cesium carbonate (12.38 g, 37.997 mmol, 4.0 equivalent), and cuprous(I) iodide (0.362 g, 1.901 mmol, 0.2 equivalent) were added, and the reactor was sealed. The mixture was stirred at 105 °C for 3 hours. UPLC indicated partial conversion of SM. Palladium(II) acetate (0.107 g, 0.477 mmol, 0.05 equivalents), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthones (0.55 g, 0.951 mmol, 0.1 equivalents), cesium carbonate (6.19 g, 18.998 mmol, 2.0 equivalents), and cuprous(I) iodide (0.181 g, 0.95 mmol, 0.1 equivalents) were added, and the reactor was evacuated and backfilled three times with argon. The reactor was resealed, and the mixture was stirred overnight at 105 °C. Another portion of palladium(II) acetate (0.107 g, 0.477 mmol, 0.05 equivalent), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.55 g, 0.951 mmol, 0.1 equivalent), cesium carbonate (6.19 g, 18.998 mmol, 2.0 equivalent), and cuprous(I) iodide (0.181 g, 0.95 mmol, 0.1 equivalent) was added, and the mixture was stirred at 105 °C for 4 hours after evacuation, backfilling with argon, and sealing. The mixture was filtered through a diatomaceous earth pad and washed with ethyl acetate. The filtrate was concentrated, and the residue was purified by FC (silica gel, DCM, and DCM / ethyl acetate 1:1) to give 1.11 g (20% yield) of the title compound. Two additional impure fractions (F2 - 0.97 g and F4 - 0.73 g) were repurified by FC (silica, DCM and DCM / ethyl acetate 1:1), combined and repurified again (silica, DCM and DCM / ACN 6:4) to give an additional 0.31 g (6% yield) of tert-butyl piperazine-1-carboxylate 4-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(3-methyloxetane-3-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate.[M+H]. + = 573.92 m / z. 1 H NMR(300MHz, DMSO-d6) δ 8.92 (s, 1H), 8.84 (t, J = 1.8Hz, 2H), 8.55 (s, 1H), 7.89- 7.84 (m, 2H), 7.12 (d, J = 4.8Hz, 1H), 4.78 (d, J = 6.4Hz, 2H), 4.71 (d, J= 6.2Hz, 2H), 3.54 (q, J= 5.5Hz, 8H), 1.79 (s, 3H), 1.44 (s, 9H).

[0380] Step 5: Add trifluoroacetic acid (1.477 ml, 19.171 mmol, 9.998 equivalents) to a solution of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(3-methyloxetane-3-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (1.134 g, 1.917 mmol, 1.0 equivalents) in anhydrous dichloromethane (35.2 ml, 32.0 v / L). Stir the mixture at room temperature for 90 min. UPLC indicated no conversion. Add trifluoroacetic acid (0.739 ml, 9.592 mmol, 5.003 equivalents) and continue stirring for 90 min. UPLC indicated complete conversion. Concentrate the mixture and evaporate three times with DCM. Grind the residue with diethyl ether (150 ml). The resulting solid (TFA salt) was purified by RP FC (C18 silica, water to water / ACN 1:1, containing 0.1% FA) to give 0.545 g (59% yield) of 7-{4-[(3-methyloxetane-3-yl)amino]-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonite as the TFA salt. LCMS: ESI(+) [M+H] + =474.32. 1H NMR (300MHz, DMSO-d6) δ 8.92 (s, 3H), 8.86 (q, J = 2.2Hz, 2H), 8.58 (s, 1H), 7.87 (d, J = 4.9Hz, 2H), 7.13 (d, J =4.8Hz, 1H), 4.78 (d, J = 6.3Hz, 2H), 4.73 (d, J = 6.2Hz, 2H), 3.83 - 3.72 (m,4H), 3.32 (s, 4H), 1.79 (s, 3H).

[0381] Intermediate X: 7-{4-[(cyanomethyl)amino]-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridine pyridine-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile; trifluoroacetate

[0382]

[0383] Step 1: Add DIPEA (23.4 mL, 133.6 mmol, 3 equivalents) to 2-bromo-4-fluoropyridine (7.84 g, 44.55 mmol, 1 equivalent) in a stirred solution of NMP (63 mL, 0.71 M). Add aminoacetonitrile-HCl (6.31 g, 66.82 mmol, 1.5 equivalents) in portions and heat the mixture to 120 °C in a pressure flask. After 12 hours, add another portion of aminoacetonitrile-HCl (3 g, 31.77 mmol, 0.7 equivalents) and DIPEA (16 mL, 91.35 mmol, 2 equivalents). Stir the reaction mixture at 120 °C for 12 hours. Dilute the reaction mixture with water and extract with EA. Wash the EA with water and brine and dry over Na₂SO₄. The crude product was purified with FC hexane / EA (0 to 95%) to give 6.0 g (64% yield) of 7-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylon. [M+H] + = 214.1 m / z. 1 H NMR (300MHz, DMSO-d6)7.94 (1 H, d, J=5.7Hz), 7.43 (1 H, t, J=6.4Hz), 6.88 (1 H, d, J=2.2Hz), 6.70 (1 H, dd, J=5.7, 2.2Hz), 4.41 (2 H, d, J=6.4Hz).

[0384] Step 2: Add 2MK3PO4 aqueous solution (31 ml, 61.31 mmol, 2.0 equivalent) to a solution of 2-[(2-bromopyridin-4-yl)amino]acetonitrile (6.5 g, 30.65 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxynitrile (11.55 g, 42.91 mmol, 1.4 equivalent) and Xphos Pd G3 (1.3 g, 1.53 mmol, 0.05 equivalent) in DME (153 ml, 0.2 M). Degas the solution with argon for 2–3 minutes, then heat to 120 °C for 5 hours. UPLC showed complete conversion of the starting materials. Dilute the resulting solution with DCM and concentrate to dryness. The crude product was purified by FC elution with EA:DCM (0 to 85%) to give 4.29 g (47% yield) of 7-{4-[(cyanomethyl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylon. [M+H] + = 275.38 m / z. 1 H NMR (300MHz, DMSO-d6) 8.82 (1 H, d, J=2.2Hz), 8.65 (1 H, d, J=2.3Hz), 8.36 (1 H, d, J=5.6Hz), 8.03 (1 H, d, J=2.3Hz), 7.79 (1 H, d, J=4.7Hz), 7.40 (1 H, t, J=6.4Hz), 7.10 (1 H, d, J=4.8Hz), 6.69 (1 H, dd, J=5.7, 2.4Hz), 4.42 (2 H, d, J=6.3Hz).

[0385] Step 3: 7-{4-[(cyanomethyl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (4.81 g, 17.54 mmol, 1 equivalent) was dissolved in an ACN / DCM / DMF (10:5:1) mixture (1.5 L, 0.011 M), and N-bromosuccinimide (2.81 g, 15.78 mmol, 0.9 equivalent) was added in a single step at room temperature. The reaction mixture was stirred at room temperature for 30 min. After completion, the mixture was evaporated, and the crude product was purified by elution with FC via DCM / EtOAc to give 2.0 g (35% yield) of 7-{5-bromo-4-[(cyanomethyl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile. [M+H] + =355.18 m / z. 1H NMR (300MHz, DMSO-d6) 8.84 (1 H, d, J=2.3Hz), 8.64 (1 H, d, J=2.2Hz), 8.52 (1 H, s), 8.14 (1 H, s), 7.79 (1 H, d, J=4.8Hz), 7.12 (1 H, d, J=4.8Hz), 7.00 (1 H, t, J=6.2Hz), 4.47 (2 H, d, J=6.2Hz).

[0386] Step 4: In a pressure vial, 7-{5-bromo-4-[(cyanomethyl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (1.04 g, 2.83 mmol, 1.0 equivalent) was dissolved in dioxane (30 mL, 0.1 M) and DMF (10 mL, 0.3 M), followed by the addition of bis(pinacol)diboron (1.44 g, 5.66 mmol, 2.0 equivalent) and KOAc (0.86 g, 8.789 mmol, 3.1 equivalent). The solution was degassed with argon for several minutes, and Pd(PPh3)2Cl2 (0.2 g, 0.283 mmol, 0.1 equivalent) was added, followed by repeated degassed. The reaction mixture was stirred at 80 °C for 24 h. UPLC showed complete conversion. The reaction mixture was diluted with EtOAc and washed with H2O and brine, and dried over Na2SO4. The crude product was ground with hexane to remove excess bis(pinacol)diboron, filtered, dried, and used in the next step without further purification.

[0387] Step 5: In a glass reactor, add tert-butyl 4-(5-bromo-1,3,4-cyanomethyl)amino]-5-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (3.17 g, 7.93 mmol, 1.0 equivalent) to a solution of 7-{4-[(cyanomethyl)amino]-5-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)piperazine-1-carboxylate (2.77 g, 7.93 mmol, 1.0 equivalent) in anhydrous dioxane (140 mL, 0.06 M). Evacuate the reactor and backfill with argon three times. Add tri-tert-butylphosphonium tetrafluoroborate (0.23 g, 0.793 mmol, 0.1 equivalent), tris(dibenzylacetone)dipalladium(0) (0.363 g, 0.397 mmol, 0.05 equivalent), and cesium fluoride (3.61 g, 23.79 mmol, 3.0 equivalent). Repeat the evacuation-backfilling process three times, seal the reactor, and stir the mixture at 70°C for 12 hours. Add additional amounts of tri-tert-butylphosphonium tetrafluoroborate (0.23 g, 0.793 mmol, 0.1 equivalent), tris(dibenzylacetone)dipalladium(0) (0.363 g, 0.397 mmol, 0.05 equivalent), and cesium fluoride (3.61 g, 23.79 mmol, 3.0 equivalent). Repeat the evacuation-backfilling process three times, seal the reactor, and stir the mixture at 70°C for 12 hours. Cool the mixture to room temperature, dilute with DCM (200 ml), and filter. Pass the residue through FC (DCM / i Purified twice with PrOH and DCM / acetone, 0.108 g (3% yield) of 4-(5-{4-[(cyanomethyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl}-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester was obtained. [M+H] + =543.65 m / z. 1 H NMR (300MHz, DMSO-d6) δ 8.91 - 8.83 (2 H, m), 8.68 (1 H, d, J=2.3Hz), 8.61 (1 H, s), 8.30 (1 H, s), 7.88 (1 H, d, J=4.8Hz), 7.15 (1 H, d, J=4.9Hz), 4.70 (2 H, d, J=6.1Hz), 3.64 - 3.48 (9 H, m), 1.44 (9 H, s).

[0388] Step 6: Add trifluoroacetic acid (5 ml, 65.68 mmol, 330 equivalents) to a solution of 4-(5-{4-[(cyanomethyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl}-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (108 mg, 0.199 mmol, 1.0 equivalent) in anhydrous dichloromethane (5 ml, 0.4 M). Stir the mixture at room temperature for 3 hours. Concentrate the mixture and co-evaporate three times with DCM. Grind the residue with diethyl ether, filter, and wash with diethyl ether. The resulting solid was purified by RP FC (C18 silica, ACN / H2O and 0.1% FA) to give 66.5 mg (58% yield) of a yellow solid of 7-{4-[(cyanomethyl)amino]-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylon; trifluoroacetate (N-51). LCMS: ESI(+) [M+H] + =443.21. 1 H NMR(300MHz, DMSO-d6) δ 9.08 (2 H, br. s), 8.87 (1 H, d, J=2.3Hz), 8.83 (1 H, t,J=6.2Hz, overlap), 8.68 (1 H, d, J=2.2Hz), 8.62 (1 H, s), 8.30 (1 H, s), 7.88 (1H, d, J=4.8Hz), 7.15 (1 H, d, J=4.8Hz), 4.71 (2 H, d, J=6.1Hz), 3.86 - 3.68 (4 H, m), 3.35 - 3.27 (4 H, m).

[0389] Intermediate Y: 7-{4-[(oxecyclobutane-3-yl)amino]-5-[5-(piperazin-1-yl)-1,3,4-thiadiazole-2-} [1,2-b]pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0390]

[0391] Step 1: DIPEA (27 mL, 156 mmol, 3.5 equivalences) was added to oxetane-3-amine-HCl (4.89 mg, 44.6 mmol, 1 equivalence) in a cooled, stirred solution of DMF (45 mL, 1 M). Then, 2-chloro-4-fluoropyridine (8.3 mL, 90 mmol, 2 equivalences) was added and the mixture was heated to 90 °C in a sealed tube. Upon completion, the solvent was removed under reduced pressure. The residue was partitioned between EtOAc and water. The organic extract was washed with brine, dried over Na2SO4, filtered, and evaporated under reduced pressure. The residue was purified by FC (acetone / DCM 10% to 50%) to give 2-chloro-N-(oxetane-3-yl)pyridine-4-amine (3.2 g, 38% yield). LCMS: ESI(+)[M+H] + = 185.10. 1 H NMR (300MHz, DMSO- d 6) 7.85 (d, J =5.8Hz, 1H), 7.63 (d, J = 6.3Hz, 1H), 6.55 - 6.33 (m, 2H), 4.85 (t, J = 6.6Hz, 2H), 4.65 (dt, J = 12.8, 6.3Hz, 1H), 4.41 (t, J = 6.1Hz, 2H).

[0392] Step 2: Add K3PO4 (6.09 g, 27.8 mmol, 2 equivalents) to a solution of 2-chloro-N-(oxetane-3-yl)pyridin-4-amine (2.59 g, 13.9 mmol, 1.0 equivalent) in DME (200 mL, 0.07 M). Degas the solution with argon for 20 min, then add 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (5.24 g, 19.5 mmol, 1.4 equivalents) and XPhos Pd G3 (841 mg, 0.97 mmol, 0.07 equivalents). Seal the pressure vessel and heat to 120 °C overnight. Filter the reaction mixture onto a diatomaceous earth mat. Wash the latter with DCM and MeOH. The mother liquor was evaporated under reduced pressure, and the residue was purified by FC (5% to 50% ACN / DCM) to give 7-{4-[(oxecyclobutan-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (1.9 g, 46% yield). LCMS: ESI(+)[M+H] + = 292.37. 1HNMR (300MHz, DMSO-d6) δ 8.80 (d, J = 2.2Hz, 1H), 8.67 (d, J = 2.2Hz, 1H), 8.21 (d, J = 5.7Hz, 1H), 7.85 (d, J = 2.1Hz, 1H), 7.76 (d, J = 4.8Hz, 1H), 7.52 (d, J = 5.9Hz, 1H), 7.08 (d, J = 4.8Hz, 1H), 6.40 (dd, J = 5.7, 2.3Hz, 1H), 4.89 (t, J = 6.5Hz, 2H), 4.68 (dt, J = 12.6, 6.1Hz, 1H), 4.50 (t, J =6.1Hz, 2H).

[0393] Step 3: A solution of 7-{4-[(oxecyclobutan-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxynitrile (1.9 g, 6.52 mmol, 1 equivalent) in a 4:1 mixture of ACN / DMF (75 mL, 0.086 M) was cooled to 0 °C. N-bromosuccinimide (1.1 g, 6.2 mmol, 0.95 equivalent) was dissolved in ACN (5 mL) and added in a single batch. The solution was stirred at 0 °C until complete (4 min) and monitored by TLC (AcOEt / hexane 1:1). A precipitate formed. The precipitate was collected by filtration, and the solid was thoroughly dried to remove residual DMF and ACN, yielding 2-bromo-1,3,4-thiadiazole (1.35 g, 56% yield). LCMS: ESI(+)[M+H] + = 370.20. 1 H NMR (300MHz, DMSO-d6) δ 8.82 (d, J = 2.2Hz,1H), 8.79 (d, J = 2.2Hz, 1H), 8.45 (s, 1H), 7.78 (d, J = 4.8Hz, 1H), 7.75 (s,1H), 7.09 (d, J = 4.8Hz, 1H), 6.87 (d, J = 3.1Hz, 1H), 4.94 (d, J = 3.2Hz, 2H), 4.76 - 4.66 (m, 3H).

[0394] Step 4: Add DIPEA (22 mL, 121.2 mmol, 4.0 equivalent) to a solution of 2-bromo-1,3,4-thiadiazole (5 g, 30.3 mmol, 1.0 equivalent) and piperazine-1-carboxylic acid tert-butyl ester (14.4 g, 75.75 mmol, 2.5 equivalent) in n-butanol (63 mL, 0.48 M). Heat the reaction mixture in an oil bath at 120 °C for 1 hour. Cool the reaction mixture and concentrate under vacuum to give a crude product. Dilute the crude product with 50 mL AcOEt and 100 mL H2O and extract with AcOEt (5 × 50 mL). Dry the combined organic layers with Na2SO4 and evaporate under vacuum to give a crude product as a deep red crystalline solid. The compound was purified by FC (hexane / AcOEt 0 to 100%) to give 7-{5-bromo-4-[(oxecyclobutane-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (5.73 g, 69% yield). LCMS: ESI(+)[M+H] + = 271.20, 1 H NMR (300MHz, DMSO-) d 6) δ: 8.85 (s, 1H), 3.47 (s, 8H), 1.43 (s, 9H).

[0395] Step 5: Degas the suspension of 7-{5-bromo-4-[(oxecyclobutan-3-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (1.3 g, 3.51 mmol, 1 equivalent), 4-(1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (1.05 mg, 3.86 mmol, 1.1 equivalent), CuI (134 mg, 0.7 mmol, 0.2 equivalent), Xantphos (406 mg, 0.7 mmol, 0.2 equivalent), and Cs₂CO₃ (4.58 mg, 14 mmol, 4.0 equivalent) in anhydrous dioxane (104 mL, 0.03 M) with argon for 15 min and add Pd(OAc)₂ (80 mg, 0.35 mmol, 0.1 equivalent). Seal the pressure vessel and heat at 105 °C overnight. The reaction mixture was filtered through diatomaceous earth, washed with AcOEt, and the solvent was evaporated under vacuum. The crude product was purified by FC (320 g column with 20 g dry silica loading, ACN / DCM gradient 0 to 100%, 25 CV). The residue was milled with Et2O (sonicated for 15 min) and filtered to give 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxecyclobutane-3-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (692 mg, 35% yield). LCMS: ESI(+)[M+H] + = 560.58. 1 H NMR (300MHz, DMSO- d 6) δ 8.94 (d, J = 4.8Hz, 1H),8.85 (d, J = 2.3Hz, 1H), 8.82 (d, J = 2.2Hz, 1H), 8.56 (s, 1H), 7.91 (s, 1H),7.86 (d, J = 4.9Hz, 1H), 7.12 (d, J = 4.9Hz, 1H), 5.07 (t, J = 6.6Hz, 2H), 4.88 (dd, J = 11.4, 5.9Hz, 1H), 4.59 (t, J = 6.2Hz, 2H), 3.55 (d, J = 5.6Hz, 7H), 3.47 (s, 5H), 1.44 (s, 7H), 1.43 (s, 6H).

[0396] Step 6: A solution of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxecyclobutane-3-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (692 mg, 1.24 mmol, 1.0 equivalent) in HFIP (4.0 mL) was heated in a microwave reactor at 140 °C for 1 h. The reaction mixture was purified by preparative HPLC to give the title compound (64 mg, 18% yield). LCMS: ESI(+)[M+H] + = 459.96. 1 H NMR (300MHz, DMSO-) d 6) δ 8.94 (d, J = 4.6Hz, 1H), 8.84 (d, J = 2.3Hz, 1H), 8.81(d, J = 2.2Hz, 1H), 8.55 (s, 1H), 7.90 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.12(d, J = 4.9Hz, 1H), 5.06 (t, J = 6.7Hz, 2H), 4.93 - 4.82 (m, 1H), 4.59 (t, J= 6.2Hz, 2H), 3.56 - 3.48 (m, 4H), 2.98 - 2.83 (m, 4H).

[0397] Intermediate Z: 7-[4-(cyclopropylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridine-2- [1,2-b]pyrrolo[1,2-b]pyridazine-3-carboxynitrile

[0398]

[0399] Step 1: TEA (19 ml, 129 mmol, 3.0 equivalents) and 1,1'-thiocarbonyldiimidazole (11.5 g, 51.54 mmol, 1.2 equivalents) were added to a stirred solution of piperazine-1-carboxylate (8 g, 42.9 mmol, 1.0 equivalents) in anhydrous THF (150 ml, 0.3 M), and the reaction mixture was stirred at room temperature for 2 hours. The solution was then transferred dropwise to a solution of hydrazine monohydrate (9.6 ml, 129 mmol, 3 equivalents) in THF (50 ml). The reaction was monitored for completion by TLC. The reaction mixture was diluted with water (500 mL), and the aqueous layer was extracted with EtOAc (2 × 500 mL). The combined organic layers were washed with brine (500 mL), dried over Na₂SO₄, and concentrated under reduced pressure. The residue was recrystallized from AcOEt / hexane (1:2) to give tert-butyl 4-(aminothiocarbamoyl)piperazine-1-carboxylate (10.09 g, 89% yield). ESI(-)[MH]+ = 259.38. 1 H NMR (300MHz, DMSO-) d 6) d 9.13 (s, 1H), 4.76 (s, 2H), 3.79 - 3.62 (m, 4H), 3.42 - 3.25 (m,4H), 1.41 (s, 9H).

[0400] Step 2: Under argon atmosphere, Et3N (4.4 ml, 1.2 equivalents) was added to a solution of starting 4,6-dichloronicotinic acid (5.645 g, 29.11 mmol, 1.1 equivalents) in anhydrous DCM (90 ml, 0.3 M), and the solution was cooled to -15°C. Isobutyl chloroformate (3.85 ml, 1.1 equivalents) was added dropwise, maintaining the temperature at -15°C. The solution was then kept at -15°C for 1 hour. Then, tert-butyl 4-(aminothiocarbamoyl)piperazine-1-carboxylate (6.89 g, 26.2 mmol, 1.0 equivalents) was added in portions, and the reaction mixture was stirred overnight at room temperature. At completion, the solution was treated with NaHCO3 and extracted with DCM (3 × 50 ml). The combined organic layers were dried over Na2SO4, filtered, and evaporated to dryness. The crude residue was ground with Et2O and filtered to give 4-{[(4,6-dichloropyridin-3-yl)formylhydrazide]methionyl}piperazine-1-carboxylic acid tert-butyl ester (8.2 g, 70% yield). ESI(-)[MH] + =434.00. 1 H NMR (300MHz, DMSO-d6) δ 10.68 (s, 1H), 9.94 (s, 1H), 8.71 (s, 1H), 7.97 (s, 1H), 3.99 - 3.80 (m, 4H), 3.47 - 3.37 (m, 4H), 1.42 (s, 9H).

[0401] Step 3a: A solution of 4-{[(4,6-dichloropyridin-3-yl)formylhydrazine]methylthioyl}piperazine-1-carboxylic acid tert-butyl ester (4.211 g, 9.21 mmol, 1.0 equivalent) in sulfuric acid (31 mL, 552.6 mmol, 60 equivalent) was stirred overnight at room temperature. The reaction mixture was poured into ice (approximately 200 mL) while stirring vigorously. K₂CO₃ was then carefully added in portions until pH > 9. The product was filtered off with K₂SO₄ and washed several times with DCM. The product was extracted from the aqueous phase with DCM (3 × 200 mL). The combined organic layers were dried over Na₂SO₄, filtered, and evaporated under reduced pressure to give 1-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine (2.276 g, 77% yield). ESI(+)[M+H] + = 316.28. 1 H NMR (300MHz, DMSO-d6) δ 8.94 (s, 1H), 8.02 (s, 1H), 3.50 - 3.45 (m, 4H), 2.87 - 2.78 (m, 4H).

[0402] Step 3b: To a solution of 1-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine (2.276 g, 7.2 mmol, 1.0 equivalent) in DCM (14 mL, 0.5 M), TEA (1.2 mL, 8.6 mmol, 1.2 equivalent) was added, and the reaction mixture was stirred for 5 min. Boc₂O (1.9 g, 8.6 mmol, 1.2 equivalent) was then added. The reaction mixture was stirred at room temperature for 1 h. At completion, the solution was evaporated to dryness under reduced pressure. The crude solid was suspended in hexane and filtered to give tert-butyl 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (2.8 g, 93% yield). ESI(+) [M+H] + =360.34. 1 H NMR (300MHz, DMSO-d6) δ 8.94 (s, 1H), 8.04 (s, 1H), 3.63 - 3.46 (m,8H), 1.43 (s, 9H).

[0403] Step 4: Cyclopropylamine (2.4 ml, 33.6 mmol, 10 equivalents) was added to a solution of 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (1.4 g, 3.4 mmol, 1.0 equivalent) in a 1:3 mixture of tert-butanol / THF (45 ml, 0.075 M), and the reaction mixture was heated to 90 °C for 24 hours. Upon completion, the solution was evaporated under reduced pressure, diluted with water (100 ml), and extracted with DCM (20 ml × 3). The organic phases were combined, dried over Na₂SO₄, filtered, and concentrated under reduced pressure to give 4-{5-[6-chloro-4-(cyclopropylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester (1.33 g, 81%). ESI(+)[M+H] + = 437.70. 1 H NMR (300MHz, DMSO- d 6) δ 8.73 (s,1H), 8.23 ​​(s, 1H), 7.05 (s, 1H), 3.52 (s, 8H), 2.73 - 2.59 (m, 1H), 1.43 (s,9H), 0.90 (q, J = 6.6Hz, 2H), 0.57 (p, J = 4.8Hz, 2H).

[0404] Step 5: Add K3PO4 (1.332 g, 6 mmol, 2.0 equivalent) to a solution of 4-{5-[6-chloro-4-(cyclopropylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester (1.33 g, 3 mmol, 1.0 equivalent) in DME (40 mL, 0.07 M) and degas the mixture with argon for 10 min. Add 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.147 g, 4.262 mmol, 1.4 equivalent) and XPhos PdG3 (0.184 g, 0.213 mmol, 0.07 equivalent) and seal the pressure vessel. Stir the mixture overnight at 120 °C. The solvent is evaporated under reduced pressure. The crude product is then passed through an FC (0 to 10%) system. i Purified by PrOH / DCM, 25 CV, to give tert-butyl piperazine-1-carboxylate (120 mg, 20% yield). ESI(+) [M+H] + = 544.48. 1H NMR (300MHz, DMSO- d 6) δ 9.36 (s, 2H), 9.12 (s, 1H), 8.92 (s, 1H), 8.84 (s, 1H), 8.60 (s, 1H), 8.52 (s, 1H), 8.05 (s, 1H), 7.19 (s, 1H), 3.80 (s, 4H), 3.30 (s, 4H), 2.83 (s, 1H), 1.41 (s, 9H), 1.06 (s, 2H), 0.70 (s, 2H).

[0405] Step 6: A solution of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclopropylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (120 mg, 0.22 mmol, 1.0 equivalent) in DCM (1 mL, 0.3 M) was cooled to 0 °C. Then, TFA (0.17 mL, 2.2 mmol, 10 equivalent) was added dropwise, and the mixture was stirred at room temperature for 3 hours. Upon completion, the mixture was evaporated to dryness. The crude product was suspended in Et2O and sonicated for 30 minutes. The suspension was filtered to give 95 mg (45% yield) of the title compound (TFA salt) as a yellow solid. LCMS: ESI(+) [M+H] + =444.48. 1 H NMR (300MHz, DMSO- d 6) δ 9.36 (s, 2H), 9.12 (s, 1H), 8.92 (s, 1H), 8.84 (s, 1H), 8.60 (s, 1H), 8.52 (s, 1H), 8.05 (s, 1H), 7.19 (s, 1H), 3.80(s, 4H), 3.30 (s, 4H), 2.83 (s, 1H), 1.06 (s, 2H), 0.70 (s, 2H).

[0406] Intermediate AA: 7-[4-(ethylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridine-2- [1,2-b]pyrrolo[1,2-b]pyridazine-3-carboxynitrile

[0407]

[0408] Step 1: A mixture of 1.4 g (3.36 mmol, 1.0 equivalent) of 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester in tert-butanol (22 mL, 0.15 M) and 2 M ethylamine in THF (2 mL, 7.1 mmol, 20.0 equivalent) was heated overnight at 90 °C. All volatiles were then evaporated under reduced pressure, and the residue was dissolved in dichloromethane, washed with water, dried, and the solvent evaporated. The crude product was ground with hexane to give 1.35 g (94% yield) of 4-{5-[6-chloro-4-(ethylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester. ESI(+) [M+H] + =425.64. 1 H NMR (300MHz, DMSO- d 6), d: 8.59 (t, J = 5.0Hz, 1H), 8.20 (s, 1H), 6.81 (s, 1H), 3.52 (m, 8H), 3.32 (br q, 2H), 1.43 (s, 9H), 1.23 (t, J =7.2Hz, 3H).

[0409] Step 2: 4-{5-[6-chloro-4-(ethylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester (1.6 g, 3.77 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.42 g, 5.27 mmol, 1.4 equivalent), K3PO4 (1.648 g, 7.531 mmol, 2.0 equivalent), and XPhos Pd G3 (0.228 g, 0.264 mmol, 0.07 equivalent) were suspended in dimethoxymethane (54 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 120 °C. The crude product was purified by FC (silica gel, dichloromethane / acetonitrile 1:1) to give 1.2 g (60% yield) of tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(ethylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate as a yellow solid. ESI(+) [M+H] + =533.0. 1H NMR (300MHz, DMSO-d6), δ: 8.84 (d, J = 2.2Hz, 1H), 8.72 (d, J =2.2Hz, 1H), 8.48 (m, 1H), 8.16 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.12 (d, J =4.8Hz, 1H), 3.54 (br m, 10H), 1.44 (s, 9H), 1.34 (t, J = 7.1Hz, 3H).

[0410] Step 3: 1.2 g (2.25 mmol, 1.0 equivalent) of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(ethylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester was dissolved in acetic acid (15 mL, 0.15 M), and a solution of HCl in diethyl ether (6 g, 22.57 mmol, 10 equivalent) was added. The reaction mixture was stirred at room temperature for 2 hours. UPLC monitoring was performed. All volatiles were then evaporated, and the crude residue was ground with a mixture of 2-propanol and diethyl ether to give 0.5 g (50% yield) of the title compound as a yellow solid. LCMS: ESI(+)[M+H] + = 432.21. 1 H NMR (300MHz, DMSO-d6), δ: 8.83 (s, 1H), 8.71 (s, 1H), 8.49 (d, J = 13.2Hz,2H), 8.15 (s, 1H), 7.84 (d, J = 4.7Hz, 1H), 7.11 (d, J = 4.6Hz, 1H), 4.12 (brm, 1H), 3.50 (m, 4H), 3.44 (br q, 2H), 2.90 (m, 4H), 1.34 (t, J = 7.1Hz, 3H).

[0411] Intermediate AB: 7-[4-(ethylamino)-5-[5-(piperazin-1-yl)-1,3,4-oxadiazol-2-yl]pyridine-2- [B]pyrrolo[1,2-b]pyridazine-3-carboxylonite tetrahydrochloride

[0412]

[0413] Step 1: A solution of 4-{[(4,6-dichloropyridin-3-yl)formylhydrazine]methylthioyl}piperazine-1-carboxylic acid tert-butyl ester (0.11 g, 0.25 mmol, 1.0 equivalent) and p-toluenesulfonyl chloride (0.082 g, 0.43 mmol, 1.7 equivalent) in anhydrous pyridine (1.3 mL, 0.2 M) was heated at 75 °C for 1.5 h with stirring. Then, all volatiles were evaporated under low pressure, and the crude product was purified by rapid chromatography (silica gel, DCM / 2-PrOH, 9:1) to give 0.06 g (52% yield) of 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-oxadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester as a grayish-white crystalline product. ESI(+) [M+H] + = 418.8. 1 H NMR (300MHz, DMSO- d 6), d: 8.93 (s, 1H), 8.05 (s, 1H), 3.51 (s, 8H), 1.43 (s, 9H).

[0414] Step 2: 0.36 g (0.865 mmol, 1.0 equivalent) of 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-oxadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester was dissolved in tert-butanol (6 mL, 0.15 M), and a 10% ethylamine THF solution (2.0 mL, 4.32 mmol, 5 equivalent) was added. The resulting mixture was heated overnight at 80 °C and, after cooling to room temperature, dissolved in dichloromethane, washed with water, and the organic phase was dried over Na₂SO₄, filtered, and evaporated to dryness under reduced pressure to give 0.32 g (77% yield) of 0.32 g (77% yield) of a grayish-white solid of 4-{5-[6-chloro-4-(ethylamino)pyridin-3-yl]-1,3,4-oxadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester. ESI(+) [M+H] + = 409.63. 1 H NMR (300MHz, DMSO-d6), δ: 8.46(s, 1H), 7.83 (d, J = 5.2Hz, 1H), 6.85 (s, 1H), 3.51 (s, 8H), 3.39 (s, 2H), 1.43 (s, 9H), 1.23 (t, J = 7.1Hz, 3H).

[0415] Step 3: 4-{5-[6-chloro-4-(ethylamino)pyridin-3-yl]-1,3,4-oxadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester (0.3 g, 0.74 mmol, 1 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (0.28 g, 1.03 mmol, 1.4 equivalent), K3PO4 (0.35 g, 1.47 mmol, 2 equivalent), and XPhos Pd G3 (0.05 g, 0.052 mmol, 0.07 equivalent) were suspended in dimethoxyethane (11 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 120 °C. The crude product was purified by rapid chromatography (silica gel, dichloromethane / 2-propanol) to give 0.2 g (51% yield) of tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(ethylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate as a yellow solid. ESI(+) [M+H] + =516.71. 1 H NMR (300MHz, DMSO-d6), δ: 8.85 (d, J = 2.2Hz, 1H), 8.77 (s, 1H), 8.74 (d, J = 2.2Hz, 1H), 8.19 (s, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.74 (t, J =5.3Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 3.58 - 3.41 (m, 10H), 1.44 (s, 9H), 1.34(t, J = 7.1Hz, 3H).

[0416] Step 4: 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(ethylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (0.2 g, 0.38 mmol, 1 equivalent) was dissolved in glacial acetic acid (2.51 mL, 0.15 M), and a solution of 1 M HCl in diethyl ether (0.915 g, 3.76 mmol, 10 equivalents) was added. The resulting mixture was stirred for 2 hours. Then, all volatiles were evaporated under reduced pressure. The residue was ground with anhydrous diethyl ether to give 0.18 g (81% yield) of the title compound as a yellow crystalline solid. LCMS: ESI(+)[M+H] += 416.25.

[0417] 1 H NMR (300MHz, DMSO-d6), δ: 9.53 (s, 2H), 9.00 (d, J = 2.1Hz, 1H), 8.86 (d, J = 2.2Hz, 1H), 8.75 (s, 2H), 8.28 (d, J = 5.0Hz, 1H), 8.12 (s, 1H), 7.24 (d, J = 5.0Hz, 1H), 3.86 (s, 4H), 3.65 (d, J = 12.8Hz, 2H), 3.29 (br m,4H), 1.35 (t, J = 7.1Hz, 3H).

[0418] Intermediate AC: 7-(4-{[(1R)-1-cyanoethyl]amino}-5-[5-(piperazin-1-yl)-1,3,4-thiadiazole- [2-yl]pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0419]

[0420] Step 1: Potassium fluoride (1.61 g, 27.623 mmol, 1.15 equivalents) and 18-crown-6 (3.18 g, 12.01 mmol, 0.5 equivalents) were added to a solution of 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (10.0 g, 24.02 mmol, 1.0 equivalents) in anhydrous dimethyl sulfoxide (80 mL, 0.3 M). The reaction mixture was stirred at 105 °C for 24 hours. After the reaction was complete, the reaction mixture was diluted with water (100 mL), and the aqueous layer was extracted with DCM (3 × 500 mL). The combined organic layers were washed with brine (150 mL), dried over anhydrous Na₂SO₄, and concentrated under vacuum. The residue was ground with hexane and then purified by silica gel rapid chromatography, eluting with 0-50% EtOAc / hexane, to give 6.7 g (70% yield) of tert-butyl 4-[5-(6-chloro-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate as a grayish-white solid. LCMS: [C 16 H 19 [ClFN5O2S], expected mass 399.1, observed mass = 399.9 [M+H] + ]. 1H NMR (300MHz, CDCl3)δ 9.21 (d, J = 9.8Hz, 1H), 7.22 (d, J = 9.8Hz, 1H), 3.62 (s, 8H), 1.49 (s,9H).

[0421] Step 2: 4-[5-(6-chloro-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (6.7 g, 16.76 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2- b Pyridazine-3-carboxynitrile (5.41 g, 20.10 mmol, 1.2 equivalents), tripotassium phosphate (7.11 g, 33.51 mmol, 2.0 equivalents), and XPos Pd G3 (0.99 g, 1.17 mmol, 0.07 equivalents) were suspended in dimethoxyethane (240 mL, 0.07 M). The mixture was degassed with argon for 20 minutes and heated to 120 °C overnight. After the reaction was complete, the mixture was concentrated under reduced pressure. The residue was purified by silica gel rapid chromatography, eluting with 100% DCM (5CV), 0-30% ACN / DCM (15CV), and 30% ACN / DCM, followed by grinding with Et2O to give 950 mg (11% yield) of tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate as a yellow solid. LCMS: [C 24 H 23 [FN8O2S], Expected mass 506.1, Observed mass = 507.0 [M+H] + ]. 1 H NMR (300MHz, CDCl3) δ 9.50(d, J = 10.2Hz, 1H), 8.69 (d, J = 12.7Hz, 1H), 8.36 (s, 1H), 8.22 (s, 1H), 8.04 (d, J = 4.6Hz, 1H), 7.02 (d, J = 4.8Hz, 1H), 3.64 (s, 8H), 1.50 (s, 9H).

[0422] Step 3: To a solution of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (5.4 g, 8.00 mmol) in anhydrous DMSO (80.0 mL, 0.1 M), D-alanine hydrochloride (9.96 g, 80.0 mmol) and sodium bicarbonate (10.1 g, 120 mmol) were added. The reaction mixture was stirred at 120 °C for 1 hour. The product was precipitated by adding ice. The suspension was stirred at room temperature for 15 minutes. The solid was collected by filtration and washed with water until the filtrate was colorless. The solid was dried under vacuum. The residue was purified by silica gel rapid chromatography, eluting with 0 to 6% MeOH / DCM, to give 1.36 g (30% yield) of 4-[5-(4-{[(1 R [1-Carbamoylethyl]amino}-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl]-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester. LCMS: C 27 H 30 N 10 The theoretical value of O3S is 574.2, and the observed value is... m / z = 575.2 [M+H] + . 1 HNMR (300MHz, DMSO- d 6 ) δ 8.85 (d, J = 2.3Hz, 1H), 8.64 (d, J = 2.3Hz, 1H),8.52 (s, 1H), 8.13 (s, 1H), 7.83 (d, J = 4.8Hz, 1H), 7.77 (s, 1H), 7.23 (s,1H), 7.13 (d, J = 4.9Hz, 1H), 6.87 (s, 1H), 4.27 (s, 1H), 3.54 (d, J = 6.8Hz, 8H), 1.50 (d, J = 6.8Hz, 3H), 1.44 (s, 9H).

[0423] Step 4: At 0℃, apply the following to 4-[5-(4-{[(1)] R[1-(1-Carbamoylethyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl]-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (1.36 g, 2.37 mmol) was added to a solution of anhydrous DCM (23.7 mL, 0.1 M) with trifluoroacetic anhydride (1.49 g, 7.1 mmol) and anhydrous pyridine (1.53 mL, 18.9 mmol). The reaction mixture was stirred at room temperature for 0.5 h. When the reaction was incomplete, another portion of trifluoroacetic anhydride (0.049 g, 0.24 mmol) and anhydrous pyridine (0.05 mL, 0.63 mmol) was added and the mixture was stirred at room temperature under argon for 30 min. A saturated aqueous solution of NaHCO3 was poured into the mixture, and the mixture was extracted with DCM to give 671 mg of crude product. The crude product was purified by rapid silica gel chromatography, eluting with 0 to 4% MeOH / DCM, to give 0.33 g (24% yield) of tert-butyl 4-[5-(4-{[(1R)-1-cyanoethyl]amino}-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate as an orange solid. LCMS: C 27 H 28 N 10 The theoretical value of O2S is 556.2, and the observed value is... m / z = 557.2 [M+H] + . 1 H NMR (300MHz, DMSO- d 6) δ 8.88 (d, J =2.3Hz, 1H), 8.83 (d, J = 6.9Hz, 1H), 8.68 (d, J = 2.3Hz, 1H), 8.64 (s, 1H), 8.37 (s, 1H), 7.88 (d, J = 4.8Hz, 1H), 7.15 (d, J = 4.8Hz, 1H), 5.04 (t, J =6.9Hz, 1H), 3.55 (d, J = 7.5Hz, 8H), 1.78 (d, J = 6.9Hz, 3H), 1.44 (s, 9H).

[0424] Step 5: Add trifluoroacetic acid (8 mL, 105 mmol) and anisole (0.381 mL, 3.48 mmol) to a solution of 4-[5-(4-{[(1R)-1-cyanoethyl]amino}-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (0.97 g, 1.7 mmol) in anhydrous dichloromethane (34.8 mL, 0.05 M). Stir the reaction mixture at room temperature for 1 hour. The evaporator was evaporated, and the residue was ground four times with diethyl ether to give 790 mg of 7-(4-{[(1R)-1-cyanoethyl]amino}-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxynitrile as a TFA salt. The salt was dissolved in 20 mL of a DCM / MeOH mixture (9:1, v / v) and washed with 30 mL of 7% NaHCO3 aqueous solution. The aqueous layer was extracted twice with a 10% MeOH solution in DCM, and the combined organic layers were washed with brine, dried over Na2SO4, and concentrated under vacuum to give 0.562 g (63% yield) of the title compound as a yellow powder. LCMS: C 22 H 20 N 10 S, expected mass = 456.2, observed m / z = 457.1 [M+H] + , 1 H NMR (300MHz, DMSO-) d 6 ) δ 8.90 - 8.80 (m, 2H), 8.68 (d, J = 2.3Hz, 1H), 8.64 (s, 1H), 8.37(s, 1H), 7.88 (d, J = 4.8Hz, 1H), 7.15 (d, J = 4.8Hz, 1H), 5.04 (t, J =7.0Hz, 1H), 3.53 (d, J = 5.2Hz, 4H), 2.89 (m, 4H), 1.78 (d, J = 6.9Hz, 3H).

[0425] Intermediate AD: 7-[4-(methylamino)-5-[5-(piperidin-4-yl)-1,3,4-thiadiazol-2-yl]pyridine-2- [1,2-b]pyrrolo[1,2-b]pyridazine-3-carboxynitrile

[0426]

[0427] Step 1: Add DIPEA (9.3 mL, 53.08 mmol, 3 equivalents) and HATU (8.1 g, 21.23 mmol, 1.2 equivalents) to a solution of 6-chloro-4-(methylamino)pyridin-3-carbazide (3.55 g, 17.69 mmol, 1 equivalent) and monomethyl-1-(tert-butoxycarbonyl)-4-piperidinecarboxylic acid (4.46 g, 19.46 mmol, 1.1 equivalents) in DMF (60 mL, 0.3 M). Stir the mixture overnight at 25 °C. Quench the reaction mixture with ice / water (600 mL) and extract with EtOAc. Wash the combined organic layers with brine, dry over Na2SO4, and concentrate under reduced pressure. The crude product was purified by FC (DCM / MeOH, 0 to 10%) to give 6.44 g of tert-butyl 4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazidecarbonyl}piperidine-1-carboxylate (85% yield). LCMS: ESI(+) [MH] - = 410.40. 1 H NMR (300MHz, chloroform-) d ) δ 10.33 (s, 1H), 9.89 (s, 1H), 8.34 (s, 1H), 8.10 (d, J = 5.1Hz, 1H), 6.66 (s, 1H), 3.95 (d, J = 13.2Hz, 2H), 2.82 (d, J = 5.0Hz, 5H), 2.47 - 2.36 (m, 1H), 1.71 (d, J = 12.5Hz, 2H),1.51 - 1.40 (m, 11H).

[0428] Step 2: Under argon atmosphere, tert-butyl 4-{N'-[6-chloro-4-(methylamino)pyridin-3-carbonyl]hydrazine carbonyl}piperidine-1-carboxylate (3.4 g, 8.25 mmol, 1 equivalent) was dissolved in anhydrous THF (275 ml, 0.03 M). The solution was warmed to 40 °C, and P2S5 (2.75 mg, 12.38 mmol, 1.5 equivalent) was added in portions while stirring vigorously. The resulting suspension was stirred under reflux for 1 hour. After completion, the volatiles were evaporated under reduced pressure. The residue was dissolved in DCM (100 ml) and stirred vigorously with an aqueous solution of K2CO3. The aqueous layer was removed using a separatory funnel, and the organic solvent was dried over Na2SO4 and concentrated under reduced pressure. The crude residue was purified by FC (0 to 50% gradient EtOAc / DCM) to give 1.82 g of tert-butyl 4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperidine-1-carboxylate (51% yield). LCMS: ESI(+)[M+H] + = 410.4. 1 H NMR (300MHz, DMSO-) d 6) δ 8.66 (d, J = 4.7Hz, 1H), 8.40 (s, 1H), 6.84 (s, 1H), 4.01(d, J = 13.1Hz, 2H), 3.53 - 3.36 (m, 1H), 2.98 (d, J = 5.0Hz, 5H), 2.09 (d, J = 10.9Hz, 2H), 1.64 (tt, J = 12.0, 6.5Hz, 2H), 1.42 (s, 9H).

[0429] Step 3: Add potassium carbonate (0.87 g, 6.295 mmol, 3 equivalents) dissolved in H2O (0.35 ml, 6.0 M) to a solution of 4-{5-[6-chloro-4-(methylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperidine-1-carboxylate (0.860 g, 2.097 mmol, 1.0 equivalents) and 7-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (0.79 g, 2.936 mmol, 1.4 equivalents) in anhydrous dioxane (7 ml, 0.3 M). The solution was degassed with argon for 15 minutes, and a complex of [1,1-bis(diphenylphosphino)ferrocene]dichloropalladium(II) and dichloromethane (0.43 g, 0.524 mmol, 0.25 equivalents) was added. The tube was sealed and stirred overnight at 120 °C. The reaction mixture was filtered through a diatomaceous earth filter and washed with DCM and MeOH. The solvent was evaporated under reduced pressure, and the residue was purified by FC (5% to 50% ACN / DCM) to give 363 mg of tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(methylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperidine-1-carboxylate (36% yield). LCMS: ESI(+) [M+H] + = 517.44. 1 H NMR (300MHz, DMSO-) d 6) δ 8.86 (d, J = 1.9Hz, 1H), 8.75 (d, J = 1.9Hz, 1H), 8.68(s, 1H), 8.65 (s, 1H), 8.21 (s, 1H), 7.89 (d, J = 4.8Hz, 1H), 7.13 (d, J =4.8Hz, 1H), 4.03 (d, J = 12.2Hz, 2H), 3.10 (d, J = 4.9Hz, 3H), 3.06 - 2.86(m, 2H), 2.11 (d, J = 11.5Hz, 2H), 1.76 - 1.56 (m, 2H), 1.43 (s, 9H).

[0430] Step 4: A solution of tert-butyl piperidine-1-carboxylate (650 mg, 1.26 mmol) in HFIP (26 mL, 0.06 M) was stirred at 140 °C for 4 hours under microwave irradiation. The volatiles were evaporated, and the residue was co-evaporated three times with DCM. The crude product was subjected to short silica gel rapid chromatography (5% to 30% MeOH / DCM) to give 474 mg (85% yield) of the title compound. LCMS: ESI(+) [M+H] + = 417.21. 1 H NMR (300MHz, DMSO- d 6) δ 8.86 (d, J = 2.2Hz, 1H), 8.76 (d, J = 2.2Hz, 1H), 8.70 (s, 1H), 8.65 (q, J = 4.3Hz, 1H), 8.21 (s,1H), 7.89 (d, J = 4.8Hz, 1H), 7.14 (d, J = 4.8Hz, 1H), 3.10 (d, J = 4.9Hz,3H), 3.08 - 2.98 (m, 2H), 2.71 - 2.58 (m, 2H), 2.09 - 1.97 (m, 2H), 1.66 (qd, J = 12.2, 3.6Hz, 2H).

[0431] Intermediate AE: 7-(5-(5-((1r,4r)-4-(methylamino)cyclohexyl)-1,3,4-thiadiazol-2-yl)-4- ((tetrahydro-2H-pyran-4-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylon hydrochloride

[0432]

[0433] Step 1: 4,6-Dichloronicotinic acid methyl ester (71.6 g, 347 mmol, 1.00 equivalent) and tetrahydro-2H-pyran-4-amine (87.9 g, 869 mmol, 2.50 equivalent) were added to... iDIEA (157 g, 1.22 mol, 212 mL, 3.50 equivalence) was added to a solution of -PrOH (700 mL). The reaction mixture was kept at 30 °C under N2 for 12 hours. The reaction mixture was poured into H2O (1.00 L) and then extracted with ethyl acetate (1.00 L × 3). The combined organic layers were washed with brine (1.00 L × 2), dried over Na2SO4, filtered, and concentrated. The residue was purified by column chromatography (SiO2, petroleum ether / ethyl acetate, gradient: 20 / 1 - 10 / 1 - 3 / 1) to give methyl 6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)nicotinic acid (43.0 g, 157 mmol, 45.4% yield, 99.4% purity) as a white solid. TLC R f = 0.30 (3:1 petroleum ether / ethyl acetate). LCMS: m / z = 271.1 (M+H) + . 1 H NMR (400MHz, CDCl3) δ 8.68 (s, 1H), 8.27 (d, J = 8.0Hz, 1H), 6.56 (s,1H), 4.01 (t, J = 3.8, 12.0Hz, 2H), 3.89 (s, 3H), 3.63 - 3.53 (m, 3H), 2.04 -1.98 (m, 2H), 1.64 (m, J = 4.2, 10.2, 13.8Hz, 2H)

[0434] Step 2: NH₂NH₂·H₂O (85.6 g, 1.45 mol, 83.2 mL, 85.0% purity, 8.03 equivalents) was added to a solution of methyl 6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)nicotinamide (49.0 g, 179 mmol, 99.4% purity, 1.00 equivalents) in EtOH (300 mL). The reaction mixture was stirred at 80 °C for 3 hours. The reaction mixture was poured into H₂O (300 mL) and then extracted with ethyl acetate (300 mL × 3). The combined organic layers were washed with brine (600 mL × 2), dried over Na₂SO₄, filtered, and concentrated to give 6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)nicotinamide (45.0 g, 166 mmol, 92.4% yield, 100% purity) as a white solid. LCMS: m / z = 271.1 (M+H) + . 1 H NMR (400MHz, DMSO) δ9.86 (s, 1H), 8.39 (d,J = 7.8Hz, 1H), 8.26 (s, 1H), 6.84 (s, 1H), 4.49 (brs, 2H), 3.82 (td, J = 3.6, 11.6Hz, 2H), 3.78 - 3.65 (m, 1H), 3.47 (dt, J =2.2, 11.2Hz, 2H), 1.88 (br d, J = 11.6Hz, 2H), 1.48 - 1.27 (m, 2H)

[0435] Step 3: Add HOBT (8.98 g, 66.4 mmol, 1.2 equivalence), EDCI (12.7 g, 66.4 mmol, 1.2 equivalence), and DIEA (21.4 g, 166 mmol, 28.9 mL, 3.00 equivalence) to a solution of 6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)nicotinamide (15.0 g, 55.4 mmol, 100% purity, 1.00 equivalence) and (1r,4r)-4-((tert-butoxycarbonyl)(methyl)amino)cyclohexane-1-carboxylic acid (15.6 g, 60.9 mmol, 1.10 equivalence) in DMF (150 mL). Stir the mixture at 25 °C under N2 for 2 hours. Pour the reaction mixture into H2O (200 mL) and extract with ethyl acetate (200 mL × 3). The combined organic layers were washed with brine (600 mL × 2), dried over Na₂SO₄, filtered, and concentrated. The residue was purified by column chromatography (SiO₂, petroleum ether / ethyl acetate = 10 / 1–5 / 1) to give a yellow solid ((1r,4r)-4-(2-(6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)nicotinyl)hydrazine-1-carbonyl)cyclohexyl)(methyl)carbamate tert-butyl ester (10.0 g, 17.3 mmol, 31.3% yield, 88.4% purity). TLC R f = 0.30 (petroleum ether / ethyl acetate = 0 / 1). LCMS: m / z = 510.1 (M+H) + . 1 H NMR (400MHz, DMSO) δ 10.37 (s, 1H), 9.85 (s, 1H), 8.39(s, 1H), 8.27 (br d, J= 7.8Hz, 1H), 6.90 (s, 1H), 3.91 - 3.67 (m, 4H), 3.52- 3.40 (m, 2H), 2.67 (s, 3H), 2.18 (br s, 1H), 1.93 - 1.80 (m, 4H), 1.71 -1.44 (m, 6H), 1.40 (s, 9H), 1.38 (br s, 2H)

[0436] Step 4: At 30°C, P2S5 (5.78 g, 26.0 mmol, 2.76 mL, 1.50 equivalent) was added to a solution of ((1r,4r)-4-(2-(6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)nicotinyl)hydrazine-1-carbonyl)cyclohexyl)(methyl)carbamate tert-butyl ester (10.0 g, 17.3 mmol, 88.4% pure, 1.00 equivalent) in THF (100 mL), and the mixture was stirred at 70°C for 2 hours. After the reaction was complete, the evaporation was evaporated. The crude residue was dissolved in DCM (150 mL) and washed with 15% K2CO3 aqueous solution (150 mL) by vigorous stirring. The organic layer was washed with water (200 mL) and brine (400 mL), dried over Na2SO4, and concentrated under vacuum. The residue was purified by column chromatography (SiO2, petroleum ether / ethyl acetate = 50 / 1 - 25 / 1 - 10 / 1) to give a yellow solid of tert-butyl ((1r,4r)-4-(5-(6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)cyclohexyl)(methyl)carbamate (6.00 g, 8.82 mmol, 50.9% yield, 74.7% purity). TLC R f = 0.20 (petroleum ether / ethyl acetate = 1 / 1). LCMS: m / z = 508.2 (M+H) + . 1 H NMR (400MHz, CDCl3) δ 9.08 (br d, J = 7.4Hz, 1H), 8.35 (s, 1H), 6.65 (s, 1H), 4.03 (td, J = 3.8, 12.0Hz, 2H), 3.75 - 3.64 (m, 1H), 3.63 - 3.55 (m, 2H), 3.09 (tt, J=3.6, 11.8Hz, 1H), 2.78 (s, 3H), 2.37 - 2.27 (m, 2H), 2.11 - 2.01 (m, 2H),1.89 (br dd, J = 2.4, 12.2Hz, 2H), 1.82 - 1.62 (m, 7H), 1.48 (s, 9H)

[0437] Step 5: Under N2, add K3PO4 (2.00 M, 11.8 mL, 2.00 equivalent) and XPhosPd to a solution of ((1r,4r)-4-(5-(6-chloro-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)cyclohexyl)(methyl)carbamate tert-butyl ester (6.00 g, 11.8 mmol, 1.00 equivalent) and 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxynitrile (4.13 g, 15.3 mmol, 1.30 equivalent) in DME (60.0 mL) to N2. G3 (999 mg, 1.18 mmol, 0.100 equivalents) was used to stir the mixture at 100 °C for 2 hours under N2. The reaction mixture was poured into H2O (100 mL) and then extracted with ethyl acetate (100 mL × 3). The combined organic layers were washed with brine (200 mL × 2), dried over Na2SO4, filtered, and concentrated. The crude product was subjected to preparative HPLC (column: Welch Ultimate XB-SiOH250). 70 10 μm; mobile phase: [hexane-EtOH (0.1% NH3·H2O)]; B%: 1%-40%, 20 min) purified, then concentrated by freeze-drying to give a yellow solid ((1r,4r)-4-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)cyclohexyl)(methyl)carbamate tert-butyl ester (2.00 g, 1.96 mmol, 16.7% yield, 60.6% purity). LCMS: m / z = 615.2 (M+H) +

[0438] Step 6: Add HCl / EtOAc (4.00 M, 489 μL, 1.00 equivalent) to a solution of ((1r,4r)-4-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)cyclohexyl)(methyl)carbamate tert-butyl (2.00 g, 1.96 mmol, 60.6% purity, 1.00 equivalent) in EtOAc (10.0 mL) and maintain at 25 °C for 15 min under N2. Concentrate the reaction mixture under vacuum. Treat the residue with EtOAc (10.0 mL) at 25 °C for 1 h, then filter and concentrate the filter cake under vacuum. A yellow solid, 7-(5-(5-((1r,4r)-4-(methylamino)cyclohexyl)-1,3,4-thiadiazol-2-yl)-4-((tetrahydro-2H-pyran-4-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile hydrochloride (1.01 g, 1.67 mmol, 85.3% yield, 91.1% purity, HCl) was obtained. LCMS: m / z = 515.1 (M+H) + . 1 H NMR: (400MHz, MeOD) δ 8.80 - 8.76 (m,2H), 8.71 (d, J = 2.0Hz, 1H), 8.16 (d, J = 5.2Hz, 1H), 8.00 (s, 1H), 7.25 (d, J = 5.2Hz, 1H), 4.42 - 4.26 (m, 1H), 4.04 (td, J = 3.8, 12.0Hz, 2H), 3.78 -3.69 (m, 2H), 3.43 - 3.32 (m, 2H), 3.20 (tt, J = 3.6, 11.8Hz, 1H), 2.75 (s,3H), 2.49 - 2.40 (m, 2H), 2.34 (br d, J = 10.4Hz, 2H), 2.20 (br d, J =12.2Hz, 2H), 1.88 - 1.77 (m, 4H), 1.71 - 1.62 (m, 2H)

[0439] Intermediate AF: 7-(5-(5-(3,8-diazabicyclo[3.2.1]oct-3-yl)-1,3,4-thiadiazol-2-yl)-4- (((S)-Tetrahydrofuran-3-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylon

[0440]

[0441] Step 1: At room temperature, TEA (57.9 mL, 3.0 equivalence) and 1,1'-thiocarbonyldiimidazole (29.61 g, 1.2 equivalence) were added to a stirred solution of 3,8-diazabicyclo[3.2.1]octane-8-carboxylate (29.4 g, 138.49 mmol, 1.0 equivalence) in THF (462 mL, 0.3 M), and the reaction mixture was stirred for 2 hours. The solution was then transferred dropwise to a solution of hydrazine monohydrate (20.80 g, 3 equivalence) in THF (130 mL). The completion of the reaction was monitored by TLC. The reaction mixture was diluted with water (500 mL), and the aqueous layer was extracted with EtOAc (2 × 500 mL). The combined organic layers were washed with brine (500 mL), dried over anhydrous Na₂SO₄, and concentrated under vacuum. The residue was resuspended in water (600 mL) and filtered. It was then washed with water to remove the imidazole byproduct, yielding 35 g (88%) of tert-butyl 3-(aminothiocarbamoyl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a pale pink solid. LCMS: [C 12 H 22 [N4O2S], Expected mass = 286.4, Observed mass = 287.3 [M+H + ]. 1 H NMR (300MHz, DMSO-d6): δ 9.05 (s, 1H), 4.76 (s, 2H), 4.40 -3.98 (m, 4H), 3.08 - 2.84 (m, 2H), 1.91 - 1.70 (m, 2H), 1.57 (d, J = 7.2Hz,2H), 1.41 (s, 9H).

[0442] Step 2: Under a dry atmosphere, add TEA (17.35 ml, 124.45 mmol, 1.2 equivalents) to a solution of starting 4,6-dichloronicotinic acid (23.89 g, 124.45 mmol, 1.2 equivalents) in anhydrous DCM (345 ml, 0.3 M) and cool the solution to -15°C. Add isobutyl chloroformate (17.0 g, 124.45 mmol, 1.2 equivalents) dropwise, maintaining the temperature at -15°C. Keep the solution at -15°C for 1 hour. Then, at this temperature, add tert-butyl 3-(aminothiocarbamoyl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate (30.0 g, 103.71 mmol, 1 equivalent) in portions and allow the reaction to return to 25°C overnight. After completion, the solution was treated with solid NaHCO3 (pH=8.0) and extracted with DCM (3×500mL). The combined organic layers were dried over Na2SO4, filtered, and evaporated to dryness. The crude residue was ground three times with hexane to give 37.5 g (79%) of 3-{[(4,6-dichloropyridin-3-yl)formylhydrazine]methionyl}-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester as a pale yellow solid, which could be used further without purification. LCMS: [C 18 H 23 [Cl2N5O3S], Expected mass = 460.34, Observed mass = 459.9 [MH] - ]. 1 H NMR (300MHz, CDCl3): δ 10.63 (s, 1H), 8.88 (s, 1H), 8.68(d, J = 19.5Hz, 1H), 7.51 (s, 1H), 4.38 (s, 4H), 3.47 - 3.27 (m, 2H), 2.13 -1.93 (m, 2H), 1.81 (t, J = 6.9Hz, 2H), 1.50 (d, J = 3.4Hz, 9H).

[0443] Step 3: Dissolve 3-{[(4,6-dichloropyridin-3-yl)formylhydrazide]methionyl}-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (37.5 g, 81.46 mmol, 1 equivalent) in H2SO4 (272 mL, 0.3 M) and stir the solution overnight at room temperature. Pour the mixture into ice with stirring and add K2CO3 until pH is approximately 10. Filter the K2SO4 and wash with DCM. Separate the layers and further extract the aqueous layer with DCM (3 × 500 mL). The combined organic layers were washed with brine (1×500 mL), dried over Na2SO4, filtered, and evaporated under reduced pressure to obtain a crude product. This crude product was ground with hexane to obtain 19.6 g (70%) of a pale yellow solid, 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane. LCMS: [C 13 H 13 [Cl2N5S], Expected mass = 341.0, Observed mass = 341.8 [M+H] + ]. 1 H NMR (300MHz, CDCl3): δ 9.14 (s, 1H), 7.49 (s, 1H), 3.72 (dd, J = 9.1, 3.1Hz, 4H), 3.47 (dd, J = 12.2, 2.8Hz, 2H), 1.91 (d, J = 2.1Hz, 5H).

[0444] Step 4: Dissolve 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane (19.6 g, 57.27 mmol, 1 equivalent) in DCM (115 ml, 0.5 M), add TEA (9.58 ml, 68.72 mmol, 1.2 equivalent), and stir the mixture for 5 minutes. Then, add Boc2O (15 g, 68.72 mmol, 1.2 equivalent), and stir the solution until complete (2 hours). Evaporate the solution to dryness under reduced pressure. The crude product was then ground with hexane (3 × 300 mL) to give 21 g (83% yield) of tert-butyl 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a pale yellow solid. LCMS: [C 18 H 21 [Cl2N5O2S], Expected mass = 441.0, Observed mass = 441.9 [M+H] + ]. 1H NMR (300MHz, CDCl3): δ 9.14 (s, 1H), 7.50 (s, 1H), 4.42 (s, 2H), 3.54 (s, 4H), 2.16 - 2.00 (m, 2H), 1.87 (d, J = 7.4Hz,2H), 1.52 (s, 9H).

[0445] Step 5: Stir a solution of 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (1.3 g, 2.94 mmol, 1.0 equivalent), (S)-3-aminotetrahydrofuran hydrochloride (2.18 g, 17.63 mmol, 6.0 equivalent), anhydrous potassium carbonate (3.24 g, 23.51 mmol, 8.0 equivalent), and DIPEA (2.56 ml, 14.69 mmol, 5.0 equivalent) in anhydrous ACN (30 ml, 0.1 M) and DMF (3 ml, 1 M) overnight at 80 °C. Then, all volatiles were removed under reduced pressure, and the crude material was purified by silica gel rapid chromatography with elution of dichloromethane / acetonitrile to give 1.0 g (62% yield) of tert-butyl 3-(5-(6-chloro-4-(((S)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a grayish-white crystalline product. ESI(+)[M+H] + = 494.0. 1 H NMR (300MHz, DMSO- d 6) d: 8.87 (d, J = 7.0Hz, 1H), 8.22 (s, 1H), 6.90 (s, 1H), 4.38 (m, 1H), 4.27 (m, 2H), 3.94 - 3.72 (m, 3H), 3.64 (m, 3H), 3.34 (m, 2H), 2.41 - 2.26 (m, 1H), 1.91 (m, 2H), 1.86 - 1.68 (m, 3H), 1.43 (s, 9H).

[0446] Step 6: 3-(5-(6-chloro-4-(((S)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (1.0 g, 1.82 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (0.709 g, 2.556 mmol, 1.4 equivalent), K3PO4 (0.775 g, 3.651 mmol, 2.0 equivalent), and XPhos Pd G3 (0.155 g, 0.18 mmol, 0.1 equivalent) was suspended in 1,2-dimethoxyethane (26.08 mL, 0.07 M). The mixture was degassed with argon for 20 min and stirred overnight at 120 °C. The crude material was purified by silica gel rapid chromatography with elution of dichloromethane / 2-propanol to give 0.7 g (56% yield) of tert-butyl 3-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(((S)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a yellow solid. ESI(+) [M+H] + = 600.47. 1 H NMR (300MHz, DMSO-d6) δ: 8.82 (d, J =2.2Hz, 1H), 8.76 - 8.68 (m, 2H), 8.49 (s, 1H), 8.18 (s, 1H), 7.83 (d, J =4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 4.30 (d, J = 11.2Hz, 3H), 4.08 - 3.99(m, 1H), 3.93 - 3.78 (m, 2H), 3.70 (t, J = 11.8Hz, 3H), 2.49 - 2.38 (m, 3H), 1.98 - 1.85 (m, 3H), 1.75 (d, J = 7.3Hz, 2H), 1.44 (s, 9H).

[0447] Step 7: Add trifluoroacetic acid (1.5 ml, 20.5 mmol, 20 equivalents) to a solution of 3-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(((S)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.7 g, 1.0 mmol, 1.0 equivalent) in anhydrous dichloromethane (3.5 ml, 0.3 M) and stir the resulting mixture at room temperature for 3 hours. After being concentrated under reduced pressure and converted to free amine, the crude product was purified by silica gel rapid chromatography with dichloromethane / methanol elution to give 0.34 g (62% yield) of 7-(5-(5-(3,8-diazabicyclo[3.2.1]oct-3-yl)-1,3,4-thiadiazol-2-yl)-4-(((S)-tetrahydrofuran-3-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile, which is a yellow solid.

[0448] LCMS: ESI(+)[M+H] + = 500.18. 1 H NMR (300MHz, DMSO-d6) δ: 8.83 (d, J =2.2Hz, 1H), 8.74 (d, J = 2.3Hz, 2H), 8.49 (s, 1H), 8.19 (s, 1H), 7.84 (d, J =4.8Hz, 1H), 7.11 (d, J = 4.8Hz, 1H), 4.35 (m, 1H), 4.06 (m, 1H), 3.95 - 3.79(m, 2H), 3.72 (m, 1H), 3.55 (m, 3H), 3.31 - 3.27 (m, 2H), 2.49 - 2.38 (m,2H), 1.99 - 1.87 (m, 1H), 1.80 - 1.65 (m, 4H).

[0449] Intermediate AG: 7-[5-(5-{2,7-diazaspiro[3.5]non-2-yl}-1,3,4-thiadiazol-2-yl)-4-(oxazolyl) [alkyl-4-ylamino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0450]

[0451] Synthesized using the same procedure as intermediate T, except that tert-butyl 2,7-diazaspiro[3.5]nonane-7-carboxylate was used. LCMS: ESI(+)[M+H] + =528.5. 1H NMR (500MHz, methanol-) d 4) δ 8.78 (d, J =2.4Hz, 1H), 8.70 (d, J = 2.3Hz, 1H), 8.56 (d, J = 2.3Hz, 1H), 8.13 (t, J =3.3Hz, 1H), 7.94 (s, 1H), 7.30 - 7.09 (m, 2H), 4.31 (s, 1H), 4.13 (d, J =2.2Hz, 4H), 4.11 - 3.97 (m, 3H), 3.74 (t, J = 11.1Hz, 2H), 3.26 (s, 5H), 2.19(q, J = 9.8, 6.5Hz, 6H), 1.78 (d, J = 11.5Hz, 2H).

[0452] Intermediate AH: 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4- (ethylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0453]

[0454] Step 1: Stir a solution of 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.44 g, 0.10 mmol, 1.0 equivalent), ethylamine solution (5 ml, 1.0 mmol, 10.0 equivalent) in anhydrous acetonitrile (23 ml, 0.1 M) and DMF (2.5 ml, 1 M) at 80 °C for 21 hours. Then, all volatiles were removed under reduced pressure, and the crude material was purified by silica gel rapid chromatography with elution of dichloromethane / acetonitrile to give 0.44 g (98% yield) of tert-butyl 3-{5-[6-chloro-4-(ethylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a grayish-white crystalline product. ESI(+)[M+H] + = 451.9. 1 H NMR (300MHz, DMSO-) d 6), d: 8.59 (t, J= 5.4Hz, 1H), 8.19 (s, 1H), 6.80 (s, 1H), 4.27 (s, 2H), 3.65 (m, 2H), 3.30 (m, 4H), 1.91 (m, 2H), 1.73 (m, 2H), 1.43(s, 9H), 1.25 (t, 3H).

[0455] Step 2: Suspend 3-{5-[6-chloro-4-(ethylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.44 g, 0.98 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.387 g, 1.4 mmol, 1.4 equivalent), K3PO4 (0.414 g, 1.951 mmol, 2.0 equivalent) and XPhos Pd G3 (0.083 g, 0.1 mmol, 0.1 equivalent) in 1,2-dimethoxyethane (13.94 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 120°C. The crude material was purified by silica gel rapid chromatography, eluting with dichloromethane / 2-propanol (9:1) to give 0.31 g (51% yield) of tert-butyl 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(ethylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a yellow solid. ESI(+) [M+H] + = 559.0. 1 H NMR (300MHz, DMSO-d6), δ: 8.83 (d, J = 2.2Hz, 1H), 8.72 (d, J = 2.2Hz, 1H), 8.49(t, J = 10.2Hz, 2H), 8.16 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.11 (d, J =4.8Hz, 1H), 4.29 (s, 2H), 3.68 (d, J = 11.2Hz, 2H), 3.50 - 3.37 (m, 4H), 1.93(s, 2H), 1.76 (d, J = 7.4Hz, 2H), 1.45 (s, 9H), 1.34 (t,J = 7.1Hz, 3H).

[0456] Step 3: Add trifluoroacetic acid (0.8 ml, 10.0 mmol, 20.0 equivalent) to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(ethylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.31 g, 0.5 mmol, 1.0 equivalent) in anhydrous dichloromethane (5.0 ml, 0.1 M) and stir the resulting mixture at room temperature for 1 hour. After evaporation of all volatiles, the crude residue was ground with anhydrous diethyl ether to give 0.21 g (89% yield) of a yellow solid, 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4-(ethylamino)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile. LCMS: ESI(+)[M+H] + = 458.09. 1 H NMR (300MHz, DMSO-d6) δ: 9.19 (m, 3H), 8.95 (d, J = 2.2Hz, 1H), 8.82 (d, J = 2.2Hz, 1H), 8.57 (s, 1H), 8.11 - 7.95 (m, 2H), 7.21 (d, J =5.0Hz, 1H), 4.23 (m, 2H), 3.95 - 3.82 (m, 2H), 3.65-3.60 (br m, 4H), 2.10 -1.91 (m, 4H), 1.34 (t, J = 7.1Hz, 3H).

[0457] Intermediate AI: 7-(4-{[(3S)-oxacyclopentan-3-yl]amino}-5-[5-(piperazin-1-yl)-1,3,4-thiadi] [Azol-2-yl]pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0458]

[0459] Step 1: Add tert-butyl 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (1.4 g, 1 equivalent) to DMF (3.3 ml, 1 M) and tDIPEA (8.7 ml, 15 equivalents) and (S)-3-aminotetrahydrofuran hydrochloride (4.12 g, 10 equivalents) were added to a solution of -BuOH (11 ml, 0.3 M). The pressure vessel was sealed and the mixture was stirred overnight at 100 °C. The solvent was evaporated under reduced pressure. The crude material was then dissolved in DCM and washed with H2O, NaHCO3, and brine. The organic phase was dried over Na2SO4, filtered, and concentrated under reduced pressure to give 420 mg (24% yield) of tert-butyl 4-[5-(6-chloro-4-{[(3S)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate. ESI(+)[M+H] + =467.26.

[0460] 1 H NMR (300MHz, DMSO- d 6) δ 8.86 (d, J = 6.9Hz, 1H), 8.22 (s, 1H), 6.91(s, 1H), 4.46 - 4.31 (m, 1H), 3.96 - 3.69 (m, 3H), 3.64 (dd, J = 9.3, 2.5Hz,1H), 3.59 - 3.44 (m, 8H), 2.45 - 2.25 (m, 1H), 1.81 (dd, J = 8.0, 5.0Hz, 1H), 1.43 (s, 9H).

[0461] Step 2: 4-[5-(6-chloro-4-{[(3S)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate tert-butyl ester (420 mg, 0.9 mmol, 1 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (0.267 g, 1.26 mmol, 1.4 equivalent), K3PO4 (0.382 g, 1.8 mmol, 2 equivalent), and XPhos Pd G3 (3.36 g, 0.063 mmol, 0.07 equivalent) were suspended in DME (13 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 120 °C. The crude material was purified by silica gel rapid chromatography, eluting with DCM / acetonitrile and DCM / i-PrOH to give 225 mg (53% yield) of a yellow solid, tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-{[(3S)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate. ESI(+) [M+H]+ = 575.42. 1 H NMR (300MHz, DMSO- d 6) δ 8.85(s, 1H), 8.80 - 8.69 (m, 2H), 8.52 (s, 1H), 8.22 (s, 1H), 7.85 (d, J = 5.0Hz, 1H), 7.12 (d, J = 4.6Hz, 1H), 4.43 - 4.27 (m, 1H), 4.10 - 4.00 (m, 1H), 4.00- 3.79 (m, 2H), 3.79 - 3.70 (m, 1H), 3.59 - 3.48 (m, 8H), 2.01 - 1.87 (m,1H), 1.44 (s, 9H).

[0462] Step 3: Add TFA (2 ml) to a solution of 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-{[(3S)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (225 mg, 0.384 mmol, 1 equivalent) in DCM (3 ml) and stir the mixture at room temperature. After 1.5 hours, evaporate the solvent under reduced pressure. Suspend the crude material in Et2O and sonicate for 30 minutes. The solid was filtered off to give 160 mg (81% yield) of a yellow solid of 7-(4-{[(3S)-oxacyclopentan-3-yl]amino}-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (TFA salt). LCMS: ESI(+)[M+H] + = 473.98. 1 H NMR (300MHz, DMSO-) d 6) δ 9.28 (s, 1H), 9.03 - 8.88 (m, 3H), 8.84 (d, J = 1.9Hz, 1H), 8.61(s, 1H), 8.14 (s, 1H), 7.99 (d, J = 4.8Hz, 1H), 7.20 (d, J = 4.9Hz, 1H), 4.53(s, 1H), 4.04 (dd, J = 9.5, 5.4Hz, 2H), 3.93 - 3.80 (m, 7H), 3.32 (s, 4H), 2.02 - 1.89 (s, 1H).

[0463] Intermediate AJ: 7-(4-{[(3R)-oxacyclopentan-3-yl]amino}-5-[5-(piperazin-1-yl)-1,3,4-thiadi] [Azol-2-yl]pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0464]

[0465] Step 1: Dissolve tert-butyl 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (1.74 g, 4.18 mmol, 1 equivalent) in DMF (4 ml, 1 M) and t -BuOH (14 ml, 0.3 M). Then, DIPEA (9 ml, 15 equivalents) and (R)-3-aminotetrahydrofuran (3.6 g, 10 equivalents) were added. The pressure vessel was sealed, and the mixture was stirred overnight at 100 °C. The solvent was evaporated under reduced pressure. The crude material was then dissolved in DCM and washed with H2O, NaHCO3, and brine. The organic phase was dried over Na2SO4, filtered, and evaporated under reduced pressure to give 1.7 g (79% yield) of tert-butyl 4-[5-(6-chloro-4-{[(3R)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate. LCMS: ESI(+)[M+H] + = 467.27. 1 H NMR (300MHz, DMSO- d 6) δ 8.86 (d, J = 6.9Hz, 1H), 8.22 (s, 1H), 6.91 (s, 1H), 4.46 - 4.31 (m, 1H), 3.96 - 3.69 (m, 3H), 3.64(dd, J = 9.3, 2.5Hz, 1H), 3.59 - 3.44 (m, 8H), 2.45 - 2.25 (m, 1H), 1.81 (dd,J = 8.0, 5.0Hz, 1H), 1.43 (s, 9H).

[0466] Step 2: 4-[5-(6-chloro-4-{[(3R)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate tert-butyl ester (1.7 g, 3.3 mmol, 1 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (1.36 g, 5.04 mmol, 1.4 equivalent), K3PO4 (1.53 g, 7.2 mmol, 2 equivalent), and XPhos Pd G3 (0.213 g, 0.252 mmol, 0.07 equivalent) were suspended in DME (52 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 120 °C. The crude material was purified by silica gel rapid chromatography, eluting with DCM / acetonitrile and DCM / i-PrOH to give 670 mg (33% yield) of a yellow solid, tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-{[(3R)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate. ESI(+)[M+H] + = 574.42. 1 H NMR (300MHz, DMSO- d 6) δ 8.84(d, J = 2.2Hz, 1H), 8.76 (d, J = 2.1Hz, 1H), 8.51 (s, 1H), 8.21 (s, 1H), 7.85(d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 4.35 (s, 2H), 4.12 - 3.71 (m,6H), 3.61 - 3.42 (m, 8H), 1.93 (s, 1H), 1.44 (s, 9H).

[0467] Step 3: Dissolve 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-{[(3R)-oxacyclopentan-3-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester (670 mg, 1.11 mmol, 1.0 equivalent) in DCM (10 mL, 0.3 M) and cool the solution to 0 °C. Then, add TFA (7.6 g, 10 equivalent) dropwise and stir the mixture at room temperature for 3 hours. At the end, evaporate the mixture to dryness. Suspend the crude product in Et2O and sonicate for 30 minutes. The solid was filtered off to give 380 mg (65% yield) of a yellow solid of 7-(4-{[(3R)-oxacyclopentan-3-yl]amino}-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxynitrile.

[0468] (TFA salt). LCMS: ESI(+)[M+H] + = 474.43. 1 H NMR (300MHz, DMSO- d 6): δ 8.96 -8.83 (m, 4H), 8.80 (d, J = 2.1Hz, 1H), 8.58 (s, 1H), 8.22 (s, 1H), 7.90 (d, J= 4.8Hz, 1H), 7.16 (d, J = 4.9Hz, 1H), 4.43 (s, 1H), 4.06 (dd, J = 9.3,5.3Hz, 1H), 3.95 - 3.72 (m, 8H), 3.35 - 3.21 (m, 4H), 2.01 - 1.86 (m, 1H).

[0469] Intermediate AK: 7-(5-(5-(3,8-diazabicyclo[3.2.1]oct-3-yl)-1,3,4-thiadiazol-2-yl)-4- (((R)-tetrahydrofuran-3-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylon

[0470]

[0471] Step 1: Stir a solution of 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (1.0 g, 2.26 mmol, 1.0 equivalent), (R)-3-aminotetrahydrofuran (1.38 g, 15.83 mmol, 7 equivalent), anhydrous potassium carbonate (2.5 g, 18.08 mmol, 8.0 equivalent) and DIPEA (1.5 ml, 11.30 mmol, 8.0 equivalent) in anhydrous acetonitrile (23 ml, 0.1 M) and DMF (2.5 ml, 1 M) overnight at 80 °C. Then, all volatiles were evaporated under reduced pressure, and the crude material was purified by silica gel rapid chromatography with elution of dichloromethane / acetonitrile to give 1.1 g (94% yield) of tert-butyl 3-(5-(6-chloro-4-(((R)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a grayish-white crystalline product. LCMS: ESI(+)[M+H] + = 493.9. 1 H NMR (300MHz, DMSO- d 6), d: 8.87 (d, J = 7.0Hz, 1H), 8.22 (s,1H), 6.90 (s, 1H), 4.37 (m, 1H), 4.27 (m, 2H), 3.87 (m, 3H), 3.65 (m, 3H), 3.34 (m, 2H), 2.39 - 2.26 (m, 1H), 1.91 (m, 2H), 1.77 (m, 3H), 1.43 (s, 9H).

[0472] Step 2: Suspend 3-(5-(6-chloro-4-(((R)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (1.1 g, 2.12 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (1.35 g, 5.27 mmol, 1.4 equivalent), K3PO4 (1.0 g, 5.1 mmol, 2.0 equivalent) and XPhos Pd G3 (0.220 g, 0.25 mmol, 0.1 equivalent) in 1,2-dimethoxyethane (36 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 120°C. The crude material was purified by silica gel rapid chromatography with elution of DCM / 2-propanol to give 0.65 g (46% yield) of tert-butyl 3-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(((R)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a yellow solid. LCMS: ESI(+)[M+H] + =574.42. H NMR (300MHz, DMSO- d 6) δ 8.84 (d, J = 2.2Hz, 1H), 8.76(d, J = 2.1Hz, 1H), 8.51 (s, 1H), 8.21 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.12(d, J = 4.8Hz, 1H), 4.35 (s, 2H), 4.12 - 3.71 (m, 6H), 3.61 - 3.42 (m, 8H), 1.93 (s, 1H), 1.44 (s, 9H).

[0473] Step 3: Add trifluoroacetic acid (1.47 ml, 19.21 mmol, 20.0 equivalent) to a solution of 3-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(((R)-tetrahydrofuran-3-yl)amino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.64 g, 0.96 mmol, 1.0 equivalent) in dichloromethane (3.5 ml, 0.3 M) and stir the resulting mixture at room temperature for 3 hours. After evaporating all volatiles under reduced pressure and converting them to free amine, the crude material was purified by silica gel rapid chromatography with dichloromethane / methanol elution to give 0.1 g (19% yield) of a yellow solid, 7-(5-(5-(3,8-diazabicyclo[3.2.1]oct-3-yl)-1,3,4-thiadiazol-2-yl)-4-(((R)-tetrahydrofuran-3-yl)amino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile. LCMS: ESI(+)[M+H] + = 500.13. 1 H NMR (300MHz, DMSO-d6) δ: 8.83 (d, J = 2.2Hz, 1H), 8.81 - 8.71(m, 2H), 8.49 (s, 1H), 8.19 (s, 1H), 7.84 (d, J = 4.8Hz, 1H), 7.11 (d, J =4.8Hz, 1H), 4.34 (s, 1H), 4.10 - 4.02 (m, 1H), 3.95 - 3.79 (m, 2H), 3.72 (m,1H), 3.52 (d, J = 9.5Hz, 4H), 3.42 (s, 1H), 2.42 (s, 2H), 1.93 (d, J = 8.3Hz, 1H), 1.71 (d, J = 5.7Hz, 4H).

[0474] Intermediate AL: 7-[4-(cyclopropylamino)-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4- [Thiadiazol-2-yl]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxynitrile bis(trifluoroacetate)

[0475]

[0476] Step 1: A solution of 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (1.0 g, 2.24 mmol, 1.0 equivalent) and cyclopropylamine (1.0 g, 17.514 mmol, 7.83 equivalent) in anhydrous acetonitrile (8 mL, 0.3 M) was stirred overnight at 80 °C. UPLC was used as a control. Then, all volatiles were removed under reduced pressure, and the crude material was purified by silica gel rapid chromatography with elution of dichloromethane / acetonitrile to give 1.0 g (87% yield) of tert-butyl 3-{5-[6-chloro-4-(cyclopropylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a grayish-white crystalline product. LCMS: ESI(+)[M+H] + = 463.9. 1 H NMR (300MHz, DMSO-) d 6) d: 8.73 (m, 1H), 8.22 (s, 1H), 7.05 (s, 1H), 4.27 (m, 2H), 3.65 (d, J = 11.4Hz, 2H), 2.68 (s, 1H), 2.58 (s, 2H), 1.92 (m, 2H), 1.73 (m,2H), 1.44 (s, 9H), 0.90 (m, 2H), 0.58 (m, 2H).

[0477] Step 2: Suspend 3-{5-[6-chloro-4-(cyclopropylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}-3,8-diazabicyclo[3.2.1]-octane-8-carboxylic acid tert-butyl ester (1.0 g, 1.9 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.77 g, 2.72 mmol, 1.4 equivalent), K3PO4 (0.825 g, 3.89 mmol, 2.0 equivalent) and XPhos Pd G3 (0.165 g, 0.194 mmol, 0.1 equivalent) in 1,2-dimethoxyethane (28 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 115°C. The crude material was purified by silica gel rapid chromatography, eluting with dichloromethane / 2-propanol (9:1) to give 0.31 g (51% yield) of tert-butyl 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclopropylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a yellow solid. ESI(+) [M+H] + = 571.1. 1 H NMR (300MHz, DMSO-d6) δ: 8.84 (d, J = 2.2Hz, 1H), 8.76 (d, J = 2.2Hz, 1H), 8.66(d, J = 4.0Hz, 2H), 8.49 (s, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.13 (d, J =4.8Hz, 1H), 4.28 (s, 2H), 3.67 (d, J = 11.5Hz, 2H), 3.37 (m, 2H), 2.74 (m,1H), 1.93 (m, 2H), 1.74 (m, 2H), 1.44 (s, 9H), 1.00 (m, 2H), 0.64 (m, 2H).

[0478] Step 3: Add trifluoroacetic acid (1.3 ml, 17 mmol, 20.0 equivalents) to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclopropylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.6 g, 0.85 mmol, 1.0 equivalent) in anhydrous dichloromethane (8.5 ml, 0.1 M) and stir the resulting mixture at room temperature for 1 hour. UPLC control was applied. After evaporation of all volatiles, the crude residue was ground with anhydrous diethyl ether to give 0.6 g (99% yield) of a yellow solid, 7-[4-(cyclopropylamino)-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxynitrile bis(trifluoroacetate). LCMS: ESI(+)[M+H] + = 470.194. 1 H NMR (300MHz, DMSO-d6) δ: 9.36(m, 2H), 9.17 (s, 1H), 8.94 (s, 1H), 8.85 (s, 1H), 8.59 (d, J = 6.9Hz, 2H), 8.00 (d, J = 4.9Hz, 1H), 7.21 (d, J = 4.9Hz, 1H), 4.24 (s, 2H), 3.87 (d, J =12.1Hz, 2H), 3.63 (d, J = 12.1Hz, 2H), 2.86 (s, 1H), 2.13 - 1.83 (m, 4H), 1.07 (m, 2H), 0.72 (m, 2H).

[0479] Intermediate AM: 7-[4-(cyclobutylamino)-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4- [Thiadiazol-2-yl]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile trifluoroacetate

[0480]

[0481] Step 1: Heat a solution of 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (1.1 g, 2.5 mmol, 1.0 equivalent) and cyclobutanamine (1.751 g, 24.618 mmol, 10.0 equivalent) in anhydrous acetonitrile (8 ml, 0.3 M) overnight at 80 °C. All volatiles were removed under low pressure, and the crude material was purified by rapid silica gel chromatography with elution of dichloromethane / acetonitrile to give 1.05 g (81% yield) of tert-butyl 3-{5-[6-chloro-4-(cyclobutylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a grayish-white crystalline product. ESI(+) [M+H] + = 479.0. 1 H NMR (300MHz, DMSO- d 6) d: 8.82(d, J = 6.2Hz, 1H), 8.20 (s, 1H), 6.68 (s, 1H), 4.27 (m, 2H), 4.15 (m, 1H), 3.66 (d, J = 11.1Hz, 2H), 2.44 (s, 3H), 1.90 (s, 4H), 1.85 - 1.66 (m, 5H), 1.43 (s, 9H).

[0482] Step 2: Suspend 3-{5-[6-chloro-4-(cyclobutylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}-3,8-diazabicyclo[3.2.1]-octane-8-carboxylic acid tert-butyl ester (1.0 g, 1.992 mmol, 1.0 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.79 g, 2.788 mmol, 1.4 equivalent), K3PO4 (0.845 g, 3.983 mmol, 2.0 equivalent) and XPhos Pd G3 (0.169 g, 0.199 mmol, 0.1 equivalent) in 1,2-dimethoxyethane (8 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and stirred overnight at 117°C. The crude material was purified by silica gel rapid chromatography, eluting with dichloromethane / 2-propanol, to give 0.47 g (38% yield) of tert-butyl 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclobutylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a yellow solid. ESI(+) [M+H] + = 584.65. 1 H NMR (300MHz, DMSO-d6) δ: 8.83 (d, J = 2.2Hz, 1H), 8.78 (d, J = 2.2Hz, 1H), 8.68(d, J = 5.2Hz, 1H), 8.48 (s, 1H), 8.10 (s, 1H), 7.84 (d, J = 4.8Hz, 1H), 7.11(d, J = 4.8Hz, 1H), 4.28 (s, 2H), 4.22 - 4.10 (m, 1H), 3.68 (d, J = 11.3Hz,2H), 2.68 - 2.52 (m, 5H), 2.05 - 1.84 (m, 6H), 1.76 (d, J = 11.3Hz, 2H), 1.44(s, 9H).

[0483] Step 3: Add trifluoroacetic acid (1.7 ml, 15 mmol, 20.0 equivalent) to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclobutylamino)-pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.47 g, 0.76 mmol, 1.0 equivalent) in anhydrous dichloromethane (8.5 ml, 0.1 M) and stir the resulting mixture at room temperature for 1 hour. All volatiles were evaporated, and the crude residue was ground with anhydrous diethyl ether to give 0.35 g (91% yield) of a yellow solid, 7-[4-(cyclobutylamino)-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile trifluoroacetate. LCMS: ESI(+) [M+H] + = 484.24. 1 H NMR (300MHz, DMSO-d6) δ: 9.27 (br m, 3H), 8.94(d, J = 2.2Hz, 1H), 8.86 (d, J = 2.2Hz, 1H), 8.59 (s, 1H), 7.99 (d, J =5.8Hz, 2H), 7.20 (d, J = 4.9Hz, 1H), 4.32 (m, 2H), 4.23 (s, 2H), 3.88 (d, J =12.9Hz, 2H), 3.69 - 3.58 (m, 2H), 2.61 (d, J = 5.3Hz, 2H), 2.14 - 1.82 (m,8H).

[0484] Intermediate AN: 7-{4-[(1-cyanocyclopropyl)amino]-5-{5-[(1R,5S)-3,8-diazabicyclo] [3.2.1]oct-3-yl]-1,3,4-thiadiazol-2-yl}pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0485]

[0486] Step 1: 3-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (5.0 g, 11.30 mmol, 1 equivalent), KF (755 mg, 12.99 mmol, 1.15 equivalent), and 18-crown-6 ether (1.49 g, 5.65 mmol, 0.5 equivalent) were dissolved in anhydrous dimethyl sulfoxide (41 mL). The reaction mixture was stirred overnight at 105 °C. The reaction mixture was then diluted with water (50 mL) and extracted with DCM (3 × 100 mL). The DCM layer was washed twice with water, then washed with brine. The organic layer was dried over Na2SO4 and filtered. The solvent was removed under vacuum. 8.3 g of the crude product was purified by FC using a gradient of 0 to 100% EtOAc / hexane to give 4.1 g of tert-butyl 3-[5-(6-chloro-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a white solid. LCMS: [C 18 H 21 [ClFN5O2S], expected mass = 425.9, observed mass = 425.9 [M+H] + ]. 1 H NMR (300MHz, DMSO-d6): δ 9.04 (d, J = 10.0Hz, 1H), 7.90 (d, J = 10.4Hz, 1H), 4.28 (s, 2H), 3.77–3.60 (m, 2H), 3.36–3.33 (m, 1H, combined with solvent residue peak), 3.39 (d, J = 2.3Hz, 1H), 1.91 (d, J = 7.1Hz, 2H), 1.74 (d, J = 7.4Hz, 2H), 1.44 (s, 9H).

[0487] Step 2: In a glass reactor, tert-butyl 3-[5-(6-chloro-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate (5.4 g, 12.68 mmol, 1.0 equivalent) was added to a solution of 3-[5-(6-chloro-4-fluoropyridin-3-yl)-1,3,4-thiadidiazol-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (4.09 g, 15.21 mmol, 1.2 equivalent) in dimethoxyethane (181 mL, 0.07 M). The reactor was evacuated and backfilled three times with argon. Xphos Pd G3 (751 mg, 0.89 mmol, 0.07 equivalent) and tripotassium phosphate (5.38 g, 25.357 mmol, 2.0 equivalent) were added. The evacuation-backfilling process was repeated three times, the reactor was sealed, and the mixture was stirred overnight at 120°C. After the reaction was complete, the mixture was cooled to room temperature, diluted with DCM (200 ml), and concentrated. The residue was purified by FC using a gradient of ACN / DCM (0 to 100%) to give 4.15 g (62% yield) of tert-butyl 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a pale yellow solid. LCMS: [C 26 [H25FN8O2S], Expected mass = 532.6, Observed mass = 533.1 [M+H + ].

[0488] 1 H NMR (300MHz, CDCl3): δ 9.52 (d, J = 10.2Hz, 1H), 8.71 (d, J =12.9Hz, 1H), 8.39 (d, J = 2.2Hz, 1H), 8.25 (d, J = 2.3Hz, 1H), 8.06 (d, J =4.9Hz, 1H), 7.04 (d, J = 4.9Hz, 1H), 4.43 (s, 2H), 3.64 (d, J = 56.8Hz, 4H), 2.06 (q, J = 8.4, 6.9Hz, 2H), 1.88 (d, J = 7.4Hz, 2H), 1.52 (s, 9H).

[0489] Step 3: Anhydrous DIPEA (10 ml, 57 mmol) was added to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate tert-butyl ester (0.50 g, 0.76 mmol) and 1-aminocyclopropane-1-carboxylonitrile hydrochloride (2.5 g, 21 mmol) in anhydrous DMSO (10 ml, 0.1 M). The reaction mixture was stirred overnight at 130 °C under an Ar atmosphere. The reaction mixture was cooled to room temperature and diluted with CH2Cl2. The organic layer was washed with brine (3 times). The organic layer was dried over MgSO4 and then concentrated under reduced pressure. The residue was purified by silica gel rapid chromatography, eluting with CH3CN / CH2Cl2 (gradient of 0% to 30% CH3CN) to give 164 mg (36% yield) of 3-(5-{4-[(1-cyanocyclopropyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl}-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester. LCMS: [C 30 H 30 N 10 O2S], observation quality = 594.70 [M+H + ]. 1 H NMR (300MHz, DMSO-d6): δ 9.03 (s,1H), 8.90 - 8.87 (m, 1H), 8.86 - 8.83 (m, 2H), 8.62 (s, 1H), 7.92 (d, J =4.8Hz, 1H), 7.16 (d, J = 4.8Hz, 1H), 4.36 - 4.24 (m, 2H), 3.78 - 3.60 (m,2H), 3.43 - 3.35 (m, 2H), 1.96 - 1.81 (m, 4H), 1.80 - 1.70 (m, 2H), 1.58 -1.47 (m, 2H), 1.44 (s, 9H).

[0490] Step 4: Add TFA (0.40 ml, 5.6 mmol) to a solution of 3-(5-{4-[(1-cyanocyclopropyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl}-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (164 mg, 0.28 mmol) in anhydrous CH2Cl2 (2.8 ml, 0.1 M). Stir the resulting mixture at room temperature for 2 hours. Remove volatiles under reduced pressure. The residue was ground with anhydrous Et2O to give 149 mg (quantitative yield) of a yellow solid, 7-{4-[(1-cyanocyclopropyl)amino]-5-{5-[(1R,5S)-3,8-diazabicyclo[3.2.1]oct-3-yl]-1,3,4-thiadiazol-2-yl}pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (TFA salt). LCMS: ESI(+)[M+H] + = 495.16. 1 H NMR (300MHz, DMSO-d6): δ 9.30 - 9.02 (m, 3H), 8.92 (d, J =2.3Hz, 1H), 8.88 (d, J = 2.3Hz, 1H), 8.86 (s, 1H), 8.67 (s, 1H), 7.95 (d, J =4.8Hz, 1H), 7.19 (d, J = 4.8Hz, 1H), 4.30 - 4.15 (m, 2H), 3.93 - 3.80 (m,2H), 3.68 - 3.53 (m, 2H), 2.10 - 1.94 (m, 4H), 1.95 - 1.83 (m, 2H), 1.56 -1.49 (m, 2H).

[0491] Intermediate AO: 7-{4-[(cyanomethyl)amino]-5-{5-[(1R,5S)-3,8-diazabicyclo[3.2.1]octyl- [3-yl]-1,3,4-thiadiazol-2-yl}pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile

[0492]

[0493] Step 1: Add DIPEA (2.6 ml, 15 mmol) to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (350 mg, 0.62 mmol) and 2-aminoacetonitrile hydrochloride (918 mg, 9.9 mmol) in DMA / CH3CN (6.5:1) (23 ml, 0.1 M). Stir the reaction mixture overnight at 110 °C under an Ar atmosphere. Cool the reaction mixture to room temperature and remove volatiles under reduced pressure. The residue was purified by silica gel rapid chromatography, eluting with CH3CN / CH2Cl2 (gradient of 0% to 20% CH3CN) to give 250 mg (63% yield) of tert-butyl 3-(5-{4-[(cyanomethyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl}-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a yellow solid. LCMS: [C 28 H 28 N 10 [O2S], observation quality = 569.10 [M+H] + ]. 1 H NMR (300MHz, DMSO-d6): δ 8.90 - 8.78 (m, 2H), 8.68 (d, J = 2.3Hz, 1H), 8.60 (s, 1H), 8.30 (s,1H), 7.87 (d, J = 4.8Hz, 1H), 7.15 (d, J = 4.8Hz, 1H), 4.69 (d, J = 6.1Hz,2H), 4.34 - 4.22 (m, 2H), 3.75 - 3.64 (m, 2H), 3.43 - 3.35 (m, 2H), 1.96 -1.87 (m, 2H), 1.81 - 1.65 (m, 2H), 1.44 (s, 9H).

[0494] Step 2: Add TFA (0.67 ml, 8.8 mmol) to a solution of 3-(5-{4-[(cyanomethyl)amino]-6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}pyridin-3-yl}-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.25 g, 0.44 mmol) in anhydrous CH2Cl2 (4.4 ml, 0.1 M). Stir the resulting mixture at room temperature for 1 hour. Remove the solvent under vacuum. The residue was purified by preparative HPLC (CH3CN / H2O + 0.1% HCOOH) to give 164 mg (75% yield) of a yellow solid, 7-{4-[(cyanomethyl)amino]-5-{5-[(1R,5S)-3,8-diazabicyclo[3.2.1]oct-3-yl]-1,3,4-thiadiazol-2-yl}pyridin-2-yl}pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (TFA salt). LCMS: ESI(+)[M+H] + = 469.39. 1 H NMR (300MHz, DMSO-d6): δ 8.88(d, J = 2.3Hz, 1H), 8.82 (t, J = 6.2Hz, 1H), 8.68 (d, J = 2.3Hz, 1H), 8.63(s, 1H), 8.31 (s, 1H), 7.87 (d, J = 4.8Hz, 1H), 7.15 (d, J = 4.8Hz, 1H), 4.70 (d, J = 6.2Hz, 2H), 4.08 - 3.98 (m, 2H), 3.83 - 3.71 (m, 2H), 3.59 - 3.46 (m,2H), 2.02 - 1.82 (m, 4H).

[0495] Intermediate AP: 7-[4-(cyclobutylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridine-2- [1,2-b]pyrrolo[1,2-b]pyridazine-3-carboxynitrile

[0496]

[0497] Step 1: In a pressure vessel, dissolve 1.2 g (1 equivalent) of 4-(5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester in DMF (3 ml, 1 M) and t-BuOH (9.5 ml, 0.3 M). Then, DIPEA (7.4 ml, 15 equivalents) and cyclobutylamine (1.4 g, 7 equivalents) were added. The pressure vessel was sealed and the mixture was warmed to 80°C overnight. The solvent was evaporated under reduced pressure, and then the crude material was dissolved in DCM and washed with H2O, NaHCO3 and brine, dried over Na2SO4, filtered and evaporated under reduced pressure to give 4-{5-[6-chloro-4-(cyclobutylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester (750 mg, 58%). LCMS: ESI(+) [M+H] + = 451.30. 1 H NMR (300MHz, DMSO- d 6) δ 8.82 (d, J = 6.2Hz, 1H), 8.21 (s, 1H), 6.69 (s, 1H), 4.15 (h, J = 8.6,8.1Hz, 1H), 3.52 (d, J = 3.9Hz, 8H), 2.48 - 2.41 (m, 2H), 1.99 - 1.72 (m,4H), 1.43 (s, 9H).

[0498] Step 2: 4-{5-[6-chloro-4-(cyclobutylamino)pyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester (750 mg, 1.63 mmol, 1 equivalent), 7-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (630 mg, 1.4 equivalent), K3PO4 (709 mg, 2 equivalent), and X Phos Pd G3 (101.6 mg, 0.07 equivalent) were suspended in DME (25 ml, 0.07 M). The mixture was degassed with argon for 20 minutes and warmed to 120°C overnight. The crude material was purified by FC (DCM / IPA 0 to 10%) to obtain tert-butyl 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclobutylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (444 mg, 48%) as a yellow solid. LCMS: ESI(+) [M+H] + = 558.44. 1 H NMR (300MHz, DMSO- d6) δ 8.83 (d, J= 2.3Hz, 1H), 8.78 (d, J = 2.3Hz, 1H), 8.68 (d, J = 5.1Hz, 1H), 8.49 (s, 1H),8.11 (s, 1H), 7.84 (d, J = 4.8Hz, 1H), 7.11 (d, J = 4.9Hz, 1H), 4.24 - 4.09 (m, 1H), 3.60 - 3.46 (m, 8H), 2.60 (d, J = 10.2Hz, 2H), 2.10 - 1.82 (m, 4H), 1.44 (s, 9H).

[0499] Step 3: Dissolve 4-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-(cyclobutylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate tert-butyl ester (444 mg, 1 equivalent) in DCM (5 ml), then add TFA (2 ml) and stir the solution for 1.5 hours. Upon completion, evaporate the mixture to dryness, suspend it in Et2O, and sonicate for 30 minutes. Filter the suspension to obtain 7-[4-(cyclobutylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (477 mg, 87%) as a TFA salt. LCMS: ESI(+) [M+H] + =458.09. 1 H NMR (300MHz, DMSO- d 6) δ 9.17 (s, 1H), 9.01 (s, 2H), 8.92 (d, J =2.2Hz, 1H), 8.85 (d, J = 2.2Hz, 1H), 8.58 (s, 1H), 8.03 (s, 1H), 7.96 (d, J =4.9Hz, 1H), 7.18 (d, J = 4.9Hz, 1H), 4.30 (dq, J = 14.2, 7.0Hz, 1H), 3.86 -3.75 (m, 4H), 3.33 (s, 4H), 2.68 - 2.54 (m, 2H), 2.15 - 1.97 (m, 2H), 1.91(dt, J = 9.6, 5.5Hz, 2H).

[0500] Intermediate AQ: 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4- {[(2R)-1-methoxypropyl-2-yl]amino}pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon, TFA salt

[0501]

[0502] Step 1: 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (660 mg, 1.24 mmol, 1 equivalent), ( R 1-Methoxypropyl-2-amine (2.21 g, 24.78 mmol, 20 equivalents) was suspended in anhydrous DMSO (12.4 mL, 0.1 M). Anhydrous DIPEA (12.1 mL, 68.16 mmol, 55 equivalents) was added. The reaction mixture was heated to 120 °C overnight. The reaction mixture was cooled to room temperature and quenched by adding water (100 mL). The solid was filtered off and washed with water (until the washings were colorless). The obtained solid was dissolved in EtOAc. The EtOAc layer was dried over Na2SO4 to remove trace amounts of water, filtered, and evaporated to give 650 mg of crude product. The crude product was purified by FC using 0 to 100% ACN / DCM to give 296 mg of semi-pure product. Attempts were made to remove impurities (m / z = 656; possibly a disubstituted Suzuki product) by grinding with MTBE and ACN, but without success. Therefore, the semi-pure product was repurified by RPFC using 5% to 95% ACN / water to give 250 mg (32% yield) of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-{[(2 R [1-Methoxypropyl-2-yl]aminopyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester. LCMS: [C 30 H 35 [N9O3S], Expected mass = 601.2, Observed mass = 602.2 [M+H] + ]. 1 H NMR (300MHz, DMSO-d6): δ8.84 (d, J = 2.2Hz, 1H), 8.73 - 8.63 (m, 2H), 8.49 (s, 1H), 8.24 (s, 1H), 7.84 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.8Hz, 1H), 4.28 (s, 2H), 4.09 - 3.94(m, 1H), 3.74 - 3.62 (m, 2H), 3.58 - 3.47 (m, 2H), 3.39 (s, 1H), 3.36 (s,4H), 1.91 (s, 2H), 1.76 (d, J = 7.5Hz, 2H), 1.44 (s, 9H), 1.32 (d, J = 6.5Hz, 3H).

[0503] Step 2: Add TFA (0.83 ml, 7.28 mmol, 20 equivalents) to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-{[(2R)-1-methoxypropyl-2-yl]amino}pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (254 mg, 0.41 mmol, 1.0 equivalent) in anhydrous DCM (3.6 ml, 0.23 M) and maintain the resulting mixture at room temperature for 1 hour. Remove volatiles by evaporation. The crude product was ground with Et2O (4 × 10 mL) to obtain 251 mg (98%) of a pale yellow solid, 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)-4-{[(2R)-1-methoxypropyl-2-yl]amino}pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (as a TFA salt). LCMS: [C 25 H 27 [N9OS], Expected mass = 501.2, Observational mass = 502.2[M+H] + ]. 1 H NMR (300MHz, DMSO-d6): δ9.35 (s, 2H), 9.25 (s, 1H), 8.94 (d, J =2.2Hz, 1H), 8.80 (d, J = 2.2Hz, 1H), 8.59 (s, 1H), 8.12 (s, 1H), 8.00 (d, J =4.9Hz, 1H), 7.20 (d, J = 4.9Hz, 1H), 4.23 (s, 3H), 3.94 - 3.81 (m, 2H), 3.69- 3.51 (m, 4H), 3.36 (s, 3H), 1.98 (dd, J = 11.8, 8.3Hz, 4H), 1.33 (d, J =6.5Hz, 3H).

[0504] Intermediate AR: 7-[4-(tert-butylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridine-2- [1,2-]pyrrolo[1,2- b ]pyridazine-3-carboxynitrile

[0505]

[0506] Step 1: Add tert-butylamine (7.45 mL, 70.89 mmol) to a suspension of 4-[5-(4,6-dichloropyridin-3-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylate (1.5 g, 3.531 mmol) in dimethyl sulfoxide (35.31 mL, 0.1 M). N , N -Diisopropylethylamine (29.0 mL, 166.487 mmol). The reaction mixture was stirred at 110 °C for 24 hours. After the reaction was complete, it was cooled to room temperature and quenched by adding ice. The precipitate formed was filtered off and dried under reduced pressure. The crude product was purified by silica gel rapid chromatography with 0-100% EtOAc / hexane to give 810 mg (51% yield) of tert-butyl piperazine-1-carboxylate as a white solid. LCMS: [C 20 H 29 [ClN6O2S], Expected mass = 452.2, Observed mass = 453.6 [M+H] + . 1 H NMR (300MHz, DMSO-d6) δ 9.02 (s, 1H), 8.20 (s, 1H), 6.86 (s, 1H), 3.57 - 3.45 (m, 8H), 1.43 (d, J = 1.9Hz, 18H).

[0507] Step 2: Add 0.88 g (1.94 mmol) of 4-{5-[4-(tert-butylamino)-6-chloropyridin-3-yl]-1,3,4-thiadiazol-2-yl}piperazine-1-carboxylic acid tert-butyl ester and 7-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyrrolo[1,2- b Pyridazine-3-carboxynitrile (0.732 g, 2.72 mmol), tripotassium phosphate (0.825 g, 3.89 mmol), and XPhos Pd G3 (0.2 g, 0.236 mmol, 0.122 equivalents) were suspended in dimethoxyethane (27.8 mL, 0.07 M). The mixture was degassed with argon for 20 min and stirred overnight at 120 °C. After the reaction was complete, the mixture was concentrated under reduced pressure. The residue was purified by silica gel rapid chromatography with 0–100% ACN / DCM to give 532.9 mg (49% yield) of a yellow solid, 4-{5-[4-(tert-butylamino)-6-{3-cyanopyrrolo[1,2- b [[pyridazine-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester. LCMS: [C 28 H 33 [N9O2S], expected mass 559.3, observed mass = 560.2 [M+H] + ]. 1 H NMR(300MHz, DMSO-d6) δ 8.84 (d, J = 2.4Hz, 2H), 8.76 (d, J = 2.3Hz, 1H), 8.56(s, 1H), 8.49 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.12 (d, J = 4.9Hz, 1H), 3.53(d, J = 6.5Hz, 8H), 1.55 (s, 9H), 1.43 (s, 9H).

[0508] Step 3: To 4-{5-[4-(tert-butylamino)-6-{3-cyanopyrrolo[1,2- b[[4-(tert-butylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]piperazine-1-carboxylic acid tert-butyl ester] (483 mg, 0.86 mmol) was added to a solution of anhydrous dichloromethane (8.6 mL, 0.1 M) with trifluoroacetic acid (1.3 mL, 17.25 mmol). The reaction mixture was stirred at room temperature for 3 hours. The mixture was then evaporated to dryness. The residue was ground with diethyl ether. The product was collected by filtration to give 600 mg (100% yield) of 7-[4-(tert-butylamino)-5-[5-(piperazin-1-yl)-1,3,4-thiadiazol-2-yl]pyridin-2-yl]pyrrolo[1,2-]pyrrolo[ ... b [Pyridazine-3-carboxynitrile (bis-TFA salt). LCMS: [C] 23 H 25 [N9S], Expected mass = 459.2, Observed mass = 460.0 [M+H] + . 1 H NMR (300MHz, DMSO- d 6 ) δ 9.34 (s, 1H), 9.04 (s, 2H), 8.92 (d, J =2.2Hz, 1H), 8.83 (d, J = 2.2Hz, 1H), 8.56 (s, 1H), 8.51 (s, 1H), 7.93 (d, J =4.9Hz, 1H), 7.18 (d, J = 4.9Hz, 1H), 3.83 - 3.75 (m, 4H), 3.31 (s, 4H), 1.57 (s, 9H).

[0509] Intermediate AS: 8-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridinium] [Pinyl-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-3-carboxylic acid tert-butyl ester

[0510]

[0511] Step 1: Add N,N-diisopropylethylamine (1.611 mL, 9.42 mmol) to a solution of tert-butyl 3,8-diazabicyclo[3.2.1]octane-3-carboxylate (0.5 g, 2.36 mmol) and 2-bromo-1,3,4-thiadiazole (0.972 g, 5.89 mmol) in n-butanol (4.71 mL, 0.5 M). Stir the reaction mixture overnight at 120 °C. After the reaction is complete, cool it to room temperature. Remove volatiles under vacuum, and transfer the residue to a separatory funnel using a mixture of EtOAc (20 mL) and H2O (40 mL). Separate the layers and extract the aqueous layer with EtOAc (3 × 20 mL). Dry the combined organic layers with Na2SO4 and concentrate under vacuum. The crude product was purified by silica gel rapid chromatography, eluting with 0 to 50% MeCN / DCM, to give 271 mg (39% yield) of tert-butyl 8-(1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-3-carboxylate as a red oil. LCMS: C 13 H 20 The theoretical value of N4O2S is 296.1, and the observed value is... m / z = 296.9 [M+H] + . 1 H NMR (300MHz, chloroform-) d ) δ 8.53 (s, 1H), 4.29 (d, J = 25.9Hz, 2H), 3.85 (dd, J = 48.5, 13.1Hz, 2H), 3.31(dd, J = 38.2, 13.1Hz, 2H), 2.11 (dt, J = 6.7, 3.8Hz, 2H), 1.90 (d, J =17.8Hz, 2H), 1.43 (s, 9H).

[0512] Step 2: Degas the suspension of 7-{5-bromo-4-[(oxapan-4-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.148 g, 0.37 mmol), 8-(1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-3-carboxylic acid tert-butyl ester (0.1 g, 0.34 mmol), cuprous iodide(I) (0.013 g, 0.067 mmol), Xantphos (0.039 g, 0.067 mmol), and cesium carbonate (0.44 g, 1.35 mmol) in anhydrous dioxane (11.25 mL, 0.03 M) with argon for 15 min, and add palladium(II) acetate (8 mg, 0.034 mmol). Seal the pressure vessel and heat at 105 °C overnight. After the reaction was complete, the evaporator was evaporated under vacuum. The residue was purified by silica gel rapid chromatography, eluting with 0 to 100% MeCN / DCM followed by 0 to 10% IPA / DCM to obtain a semi-pure product. This was further ground with diethyl ether (4 × 10 mL) to give 80 mg (34% yield) of 8-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-3-carboxylic acid tert-butyl ester as a bright yellow powder. LCMS: C 31 H 35 The theoretical value of N9O3S is 613.2, and the observed value is... m / z = 614.1 [M+H] + . 1 H NMR (300MHz, DMSO- d 6) δ 8.85 (d, J = 2.3Hz, 1H), 8.78 (d, J = 2.3Hz, 1H), 8.67 (d, J = 7.0Hz, 1H),8.52 (s, 1H), 8.31 (s, 1H), 7.85 (d, J = 4.8Hz, 1H), 7.13 (d, J = 4.8Hz, 1H),4.35 (s, 2H), 4.01 - 3.81 (m, 5H), 3.61 (s, 3H), 2.14 (s, 2H), 2.03 (s, 2H),1.75 (d, J = 7.4Hz, 3H), 1.58 (d, J= 10.8Hz, 3H), 1.42 (s, 9H).

[0513] Step 3: Add trifluoroacetic acid (0.785 g, 6.88 mmol) to a solution of 8-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-3-carboxylic acid tert-butyl ester (0.08 g, 0.12 mmol) in anhydrous dichloromethane (11.5 mL, 0.01 M). Stir the reaction mixture at room temperature for 2 hours. After the reaction is complete, evaporate the evaporator under vacuum and grind the residue with diethyl ether (4 × 10 mL). The residue was thoroughly dried to give 47 mg (77% yield) of a yellow solid of 7-[5-(5-{3,8-diazabicyclo[3.2.1]oct-8-yl}-1,3,4-thiadiazol-2-yl)-4-[(oxan-4-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon. LCMS: C 26 H 27 The theoretical value of N9OS is 513.2, and the observed value is... m / z = 514.1 [M+H] + . 1 H NMR (300MHz, DMSO-) d 6) δ 9.13 (s, 2H), 8.92 (d, J = 2.2Hz, 1H), 8.83 (d, J = 2.2Hz, 1H),8.59 (s, 1H), 8.24 (s, 1H), 7.94 (d, J = 4.9Hz, 1H), 7.18 (d, J = 4.9Hz, 1H), 4.50 (s, 3H), 3.94 (d, J = 11.7Hz, 4H), 3.39 (q, J = 6.9Hz, 4H), 3.25 (d, J =12.5Hz, 3H), 2.55 (s, 2H), 2.18 - 2.05 (m, 4H), 1.59 (d, J = 10.5Hz, 3H).

[0514] Intermediate AT: 7-[5-(5-{3,9-diazabicyclo[3.3.1]non-3-yl}-1,3,4-thiadiazol-2-yl)-4- [(oxan-4-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylon

[0515]

[0516] Step 1: Add tert-butyl 3,9-diazabicyclo[3.3.1]nonane-9-carboxylate (0.55 g, 2.41 mmol) to a solution of n-butanol (4.82 mL, 0.5 M) containing 2-bromo-1,3,4-thiadiazole (1.00 g, 6.08 mmol) and DIPEA (1.66 mL, 9.72 mmol). Stir the reaction mixture at 120 °C for 2 hours. Remove volatiles under vacuum, and transfer the residue to a separatory funnel using a mixture of EtOAc (50 mL) and H2O (100 mL), followed by extraction with EtOAc (5 × 50 mL). Dry the combined organic layers with Na2SO4 and concentrate under vacuum. The residue was purified by silica gel rapid chromatography, eluting with 0 to 70% MeCN / DCM, to give 0.506 g (67% yield) of tert-butyl 3-(1,3,4-thiadiazol-2-yl)-3,9-diazabicyclo[3.3.1]nonane-9-carboxylate as a red oil. LCMS: C 13 H 20 The theoretical value of N4O3S is 310.2, and the observed value is... m / z = 311.3 [M+H] + . 1 H NMR (300MHz, DMSO- d 6 ) δ 8.80 (s, 1H), 4.18 (d, J = 12.3Hz, 2H), 3.81(dd, J = 12.2, 4.4Hz, 2H), 3.38 (d, J = 4.3Hz, 2H), 1.92 (dt, J = 11.8,5.7Hz, 1H), 1.84 - 1.61 (m, 4H), 1.51 (s, 1H), 1.44 (m, 9H).

[0517] Step 2: Degas the suspension of 7-{5-bromo-4-[(oxan-4-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylonitrile (0.208 g, 0.522 mmol), 3-(1,3,4-thiadiazol-2-yl)-3,9-diazabicyclo[3.3.1]nonane-9-carboxylic acid tert-butyl ester (0.152 g, 0.475 mmol), CuI (0.018 g, 0.095 mmol), Xantphos (0.055 g, 0.095 mmol) and Cs2CO3 (0.619 g, 1.9 mmol) in anhydrous dioxane (15.83 mL, 0.03 M) with argon for 15 min, and add Pd(OAc)2 (0.011 g, 0.047 mmol, 0.1 equivalent). The reaction mixture was stirred at 130 °C for 2 hours in a microwave reactor. When the reaction was incomplete, additional Xantphos (0.055 g, 0.095 mmol), Cs₂CO₃ (0.619 g, 1.9 mmol), CuI (0.018 g, 0.095 mmol), and Pd(OAc)₂ (0.011 g, 0.047 mmol) were added, and the reaction mixture was degassed by vacuum / argon circulation. The reactants were then heated at 130 °C for 2 hours under microwave irradiation. After the reaction was complete, the reaction mixture was cooled to room temperature and the volatiles were evaporated under vacuum. The crude product was purified by silica gel rapid chromatography, eluting with 0 to 100% ACN / DCM followed by 0 to 10% IPA / DCM, to give 0.056 g (19% yield) of tert-butyl 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,9-diazabicyclo[3.3.1]nonane-9-carboxylate as a yellow solid. LCMS: C 32 H 37 The theoretical value of N9O3S is 627.3, and the observed value is... m / z = 628.2 [M+H] + . 1 H NMR (300MHz, DMSO- d 6 ) δ 8.85 (d, J = 2.3Hz, 1H), 8.77 (d, J = 2.3Hz, 1H), 8.71 (d, J = 7.1Hz, 1H), 8.52 (s, 1H), 8.29 (s,1H), 7.85 (d, J = 4.8Hz, 1H), 7.13 (d, J= 4.8Hz, 1H), 4.23 (d, J = 12.6Hz,2H), 3.98 - 3.81 (m, 5H), 3.61 (t, J = 10.7Hz, 2H), 3.48 (d, J = 10.5Hz, 2H), 2.12 (d, J = 13.4Hz, 2H), 1.97 (s, 1H), 1.76 (d, J = 25.0Hz, 4H), 1.58 (d, J = 11.3Hz, 3H), 1.45 (s, 9H).

[0518] Step 3: To a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,9-diazabicyclo[3.3.1]nonane-9-carboxylic acid tert-butyl ester (0.056 g, 0.09 mmol) in DCM (0.9 mL, 0.1 M), add dropwise a solution of 4 M HCl in dioxane (0.707 mL, 2.83 mmol). Stir the reaction mixture overnight at room temperature. After completion, filter out any solid residue from the reaction mixture and wash with DCM. The solid was collected and dried under vacuum to give 0.038 g (75% yield) of a yellow solid of 7-[5-(5-{3,9-diazabicyclo[3.3.1]non-3-yl}-1,3,4-thiadiazol-2-yl)-4-[(oxan-4-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile (2×HCl salt). LCMS: C 27 H 29 The theoretical value of N9OS is 527.2, and the observed value is... m / z = 528.2 [M+H] + , 1 HNMR (300MHz, DMSO- d 6 ) δ 9.68–9.32 (m, 3H), 8.98 (d, J = 2.3Hz, 1H), 8.87 (d, J = 2.2Hz, 1H), 8.57 (s, 1H), 8.16 (s, 1H), 8.10 (s, 1H), 7.23 (d, J = 5.0Hz, 1H), 4.11 (d, J= 13.1Hz, 3H), 3.88 (dd, J = 33.2, 15.8Hz, 6H), 3.61 (t, J =10.8Hz, 3H), 2.17 - 1.94 (m, 6H), 1.62 (d, J = 11.5Hz, 4H).

[0519] Intermediate AU: 7-(4-{[(1 R )-1-cyanoethyl]amino}-5-(5-{3,8-diazabicyclo[3.2.1]octyl- 3-yl}-1,3,4-thiadiazole-2-yl)pyridin-2-yl)pyrrolo[1,2- b ]pyridazine-3-carboxynitrile

[0520]

[0521] Step 1: Add 3-[5-(6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazine-7-yl]-4-fluoropyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.5 g, 0.94 mmol, 1.0 equivalent) was dissolved in anhydrous dimethyl sulfoxide (9.39 ml, 0.1 M). D-alanine hydrochloride (1.169 g, 9.4 mmol, 10.0 equivalent) and sodium bicarbonate (1.183 g, 14.08 mmol, 15.0 equivalent) were added to the solution. The resulting mixture was stirred at 120 °C for 1 hour. After the reaction was complete, it was cooled to room temperature and injected directly onto a column, and purified using 0–60% water / ACN as the mobile phase to give 0.3 g (53% yield) of 3-[5-(4-{[(1 R )-1-carbamoylethyl]amino}-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester. LCMS: [C 29 H 32 N 10 [O3S], Expected mass = 600.7, Observed mass = 601.2 [M+H] + . 1 H NMR (300MHz, DMSO- d6) δ 8.90 - 8.81 (m, 2H), 8.64 (d, J = 2.3Hz, 1H), 8.51 (s, 1H), 8.12 (s, 1H), 7.83 (d, J = 4.8Hz, 1H), 7.79 (s, 1H), 7.23 (s,1H), 7.13 (d, J = 4.8Hz, 1H), 4.38 - 4.19 (m, 3H), 3.79 - 3.63 (m, 2H), 3.44- 3.35 (m, 2H), 1.93 (s, 2H), 1.86 - 1.69 (m, 3H), 1.50 (d, J = 6.8Hz, 3H), 1.45 (s, 9H).

[0522] Step 2: 3-[5-(4-{[(1)] R )-1-carbamoylethyl]amino}-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.3 g, 0.499 mmol, 1.0 equivalent) was suspended in anhydrous dichloromethane (9.99 mL, 0.05 M), followed by the addition of anhydrous pyridine (0.322 mL, 3.995 mmol, 8.0 equivalent). Trifluoroacetic anhydride (0.315 g, 1.498 mmol, 3.0 equivalent) was added to the resulting suspension, and the reaction mixture was stirred at room temperature for 30 min. The formation of a clear solution was observed. The reaction mixture was then concentrated under vacuum, dissolved in a minimal amount of DCM, and injected onto a column. The crude product was purified by rapid chromatography using DCM-IPA 0-10% as the mobile phase to obtain 0.182 g (62% yield) of a yellow solid, 3-[5-(4-{[(1 R )-1-cyanoethyl]amino}-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester. LCMS: [C 29 H 30 N 10 [O2S], Expected mass = 582.6, Observed mass = 583.8 [M+H] + . 1 H NMR (300MHz, DMSO- d6) δ 8.87 (d, J = 2.3Hz, 1H), 8.84 (d,J = 6.9Hz, 1H), 8.68 (d, J = 2.3Hz, 1H), 8.63 (s, 1H), 8.36 (s, 1H), 7.88 (d,J = 4.8Hz, 1H), 7.15 (d, J = 4.8Hz, 1H), 5.11 - 4.97 (m, 1H), 4.40 - 4.22 (m,2H), 3.76 - 3.64 (m, 2H), 3.42 - 3.37 (m, 2H), 2.04 - 1.86 (m, 2H), 1.84 -1.69 (m, 5H), 1.44 (s, 9H).

[0523] Step 3: 3-[5-(4-{[(1)] R )-1-cyanoethyl]amino}-6-{3-cyanopyrrolo[1,2- b [[(1]pyridazine-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.182 g, 0.312 mmol, 1.0 equivalent) was dissolved in anhydrous DCM (6.25 ml, 0.05 M). TFA (0.712 g, 6.247 mmol, 20.0 equivalent) was added. The resulting mixture was stirred at room temperature for 4 hours. After the reaction was complete, it was concentrated under vacuum. The residue was ground and sonicated with diethyl ether to give a yellow precipitate, which was collected by filtration and vacuum dried overnight to give 0.288 g (92% yield) of a yellow solid of 7-(4-{[(1) R )-1-cyanoethyl]amino}-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)pyridin-2-yl)pyrrolo[1,2- b [Pyridazine-3-carboxynitrile. LCMS: [C] 28 H 24 F6N 10 [O4S], Expected mass = 482.5, Observed mass = 483.8 [M+H] + . 1 H NMR (300MHz, DMSO- d6) δ 9.13 (s, 1H), 9.05 (s, 1H), 8.89 (d, J = 2.2Hz, 1H), 8.84 (d, J =6.9Hz, 1H), 8.70 (d, J = 2.3Hz, 1H), 8.67 (s, 1H), 8.37 (s, 1H), 7.90 (d, J =4.8Hz, 1H), 7.17 (d, J = 4.8Hz, 1H), 5.08 (p, J = 6.8Hz, 1H), 4.28 - 4.19 (m,2H), 3.92 - 3.83 (m, 2H), 3.64 - 3.58 (m, 2H), 2.12 - 1.93 (m, 4H), 1.78 (d,J = 6.9Hz, 3H)。

[0524] Intermediate AV: 7-(5-(5-(3,8-diazabicyclo[3.2.1]oct-3-yl)-1,3,4-thiadiazol-2-yl)-4- (isoxazo-4-ylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylon

[0525]

[0526] Step 1: Add 1,2-oxazol-4-amine (789 mg, 9.4 mmol) to a solution of 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (500 mg, 0.94 mmol) in AcOH (9.5 mL, 0.1 M). Stir the reaction mixture overnight at room temperature. After the reaction is complete, evaporate acetic acid and partition the residue between saturated NaHCO3 (50 mL) and DCM (100 mL). Separate the layers and further wash the aqueous layer with DCM (2 × 100 mL). Wash the combined organic layers with brine (1 × 100 mL). Dry the DCM layer with anhydrous Na2SO4, filter, and concentrate under reduced pressure to give 900 mg of crude product. The crude product was combined with the test reactants and purified by silica gel rapid chromatography using 0 to 10% IPA / DCM to give 600 mg of semi-pure product. This was then repurified by RPFC using ACN / water containing 0.1% FA, followed by elution from the column with 95% THF, 0.1% TFA, and 4.9% water to give 305 mg (54% yield) of tert-butyl 3-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(isoxazol-4-ylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate as a pale yellow solid. LCMS: [C29H28N10O3S], expected mass = 596.2, observed mass = 597.1 [M+H] + . 1 HNMR (300MHz, DMSO-d6) δ 10.12 (s, 1H), 9.28 (s, 1H), 9.02 (s, 1H), 8.70 -8.63 (m, 2H), 8.41 (s, 1H), 8.19 (d, J = 5.8Hz, 1H), 7.87 (d, 1.77 (d, J = 7.5Hz, 2H), 1.45 (s, 9H).

[0527] Step 2: Add TFA (1.72 g, 15.11 mmol) to a solution of 3-(5-(6-(3-cyanopyrrolo[1,2-b]pyridazin-7-yl)-4-(isoxazol-4-ylamino)pyridin-3-yl)-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (305 mg, 0.511 mmol) in anhydrous DCM (3.8 ml, 0.2 M) and maintain the resulting mixture at room temperature for 1 hour. Remove volatiles by evaporation. The crude product was ground with Et2O (4 × 10 mL) to obtain 315 mg (100% yield) of a pale yellow solid, 7-(5-(5-(3,8-diazabicyclo[3.2.1]oct-3-yl)-1,3,4-thiadiazol-2-yl)-4-(isoxazol-4-ylamino)pyridin-2-yl)pyrrolo[1,2-b]pyridazine-3-carboxylon. LCMS: [C24H20N10OS], expected mass = 496.15, observed mass = 497.2 [M+H] + . 1 H NMR (300MHz, DMSO-d6) δ 10.12 (s, 1H), 9.29 (s, 3H), 9.01 (s, 1H), 8.85 (d, J = 2.2Hz, 1H), 8.69 (d,J = 1.6Hz, 2H), 8.38 (s, 1H), 7.87 (d, J = 4.9Hz, 1H), 7.13 (d, J = 4.8Hz, 1H), 4.24 (s, 2H), 3.88 (d, J = 12.7Hz, 2H), 3.63 (d, J = 12.8Hz, 2H), 2.09 -1.92 (m, 4H).

[0528] Intermediate AW: 7-(4-{[(1S)-1-cyanoethyl]amino}-5-(5-{3,8-diazabicyclo[3.2.1]octyl- 3-yl}-1,3,4-thiadiazole-2-yl)pyridin-2-yl)pyrrolo[1,2- b ]pyridazine-3-carboxynitrile

[0529]

[0530] Step 1: At room temperature, apply the mixture to 3-[5-(6-{3-cyanopyrrolo[1,2-]]. b [[3.2.1]pyridazine-7-yl]-4-fluoropyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.471 mg, 0.88 mmol) in N L-alanine hydrochloride (0.33 g, 2.65 mmol) was added to a solution of methylpyrrolidone (5.9 mL, 0.15 M). N , N-Diisopropylethylamine (0.79 mL, 4.42 mmol). The reaction mixture was stirred overnight at 120 °C. After the reaction was complete, the solvent was removed under reduced pressure. The residue was purified by silica gel rapid chromatography, eluting with 0–6% MeOH / DCM, to give 0.332 g (62% yield) of a yellow gel-like 3-[5-(4-{[(1 S )-1-carbamoylethyl]amino}-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester. LCMS: [C 29 H 32 N 10 [O3S], Expected mass = 600.2, Observed mass = 601.3 [M+H] + . 1 H NMR (300MHz, DMSO- d 6) δ 8.85 (q, J = 2.3, 1.6Hz, 2H), 8.63 (d, J =2.2Hz, 1H), 8.51 (s, 1H), 8.11 (s, 1H), 7.82 (d, J = 4.8Hz, 1H), 7.76 (s,1H), 7.22 (s, 1H), 7.12 (d, J = 4.8Hz, 1H), 4.27 (d, J = 7.1Hz, 3H), 3.70 (d, J = 11.8Hz, 2H), 3.37 (d, J = 11.8Hz, 3H), 1.91 (s, 2H), 1.76 (d, J = 7.4Hz, 2H), 1.50 (d, J = 6.7Hz, 3H), 1.44 (s, 9H).

[0531] Step 2: To 3-[5-(4-{[(1S)-1-carbamoylethyl]amino}-6-{3-cyanopyrrolo[1,2- b[3.2.1]-Pyridazin-7-ylpyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (332 mg, 0.55 mmol) was added to an ice-cold solution of anhydrous dichloromethane (42.5 mL, 0.01 M) with trifluoroacetic anhydride (0.23 mL, 1.66 mmol) and anhydrous pyridine (0.36 mL, 4.42 mmol). The reaction mixture was stirred at room temperature for 30 minutes. After the reaction was complete, the solvent was removed under reduced pressure. The residue was purified by silica gel rapid chromatography, eluting with 0-5% MeOH / DCM, to give 0.195 g (63% yield) of a yellow solid of 3-[5-(4-{[(1 S )-1-cyanoethyl]amino}-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester. LCMS: [C 29 H 30 N 10 [O2S], Expected mass = 582.2, Observed mass = 583.1 [M+H] + . 1 H NMR (300MHz, DMSO-) d 6) δ 8.91 - 8.79 (m, 2H), 8.68 (d, J = 2.3Hz, 1H), 8.63 (s,1H), 8.37 (s, 1H), 7.88 (d, J = 4.8Hz, 1H), 7.15 (d, J = 4.9Hz, 1H), 5.04 (t, J = 6.8Hz, 1H), 4.29 (s, 2H), 3.70 (d, J = 11.8Hz, 2H), 3.39 (d, J = 11.7Hz,2H), 1.98 - 1.89 (m, 2H), 1.77 (t, J = 6.7Hz, 5H), 1.45 (s, 9H).

[0532] Step 3: At room temperature, apply 3-[5-(4-{[(1 S )-1-cyanoethyl]amino}-6-{3-cyanopyrrolo[1,2- b[[(1S)-1-cyanoethyl]amino]-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.195 g, 0.35 mmol) was added to a solution of anhydrous dichloromethane (1.75 mL, 0.2 M) with trifluoroacetic acid (0.54 mL, 7.00 mmol). The reaction mixture was stirred at room temperature for 1 hour. After the reaction was complete, the solvent was removed under reduced pressure. The residue was purified by grinding with diethyl ether (3 × 20 mL) to give 227.8 mg (96% yield) of 7-(4-{[(1S)-1-cyanoethyl]amino}-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)pyridin-2-yl)pyrrolo[1,2-]octane-8-carboxylic acid tert-butyl ester (0.195 g, 0.35 mmol) in yellow solid. b [Pyridazine-3-carboxynitrile. LCMS: [C] 24 H 22 N 10 [S], Expected mass = 482.2, Observed mass = 483.0 [M+H] + . 1 H NMR (300MHz, DMSO- d 6) δ 9.19 - 9.07 (m, 1H), 9.10 - 8.98 (m, 1H), 8.89(d, J = 2.3Hz, 1H), 8.86 (d, J = 8.1Hz, 1H), 8.70 (d, J = 2.3Hz, 1H), 8.67(s, 1H), 8.35 (s, 1H), 7.90 (d, J = 4.7Hz, 1H), 7.16 (d, J = 4.9Hz, 1H), 5.08(t, J = 6.9Hz, 1H), 4.22 (s, 2H), 3.87 (d, J = 13.1Hz, 2H), 3.60 (d, J =12.7Hz, 2H), 2.04 - 1.92 (m, 4H), 1.77 (d, J = 6.9Hz, 3H).

[0533] Intermediate AX: 7-{4-[(1-cyano-1-methylethyl)amino]-5-(5-{3,8-diazabicyclo[3.2.1] Oct-3-yl}-1,3,4-thiadiazol-2-yl)pyridin-2-yl}pyrrolo[1,2- b ]pyridazine-3-carboxynitrile

[0534]

[0535] Step 1: 3-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-fluoropyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.5 g, 0.939 mmol, 1.0 equivalent) was dissolved in anhydrous dimethyl sulfoxide (9.39 ml, 0.1 M), followed by the addition of 2-amino-2-methylpropionamide hydrochloride (1.301 g, 9.388 mmol, 10.0 equivalent) and sodium bicarbonate (1.183 g, 14.082 mmol, 15.0 equivalent). The resulting mixture was stirred overnight at 120 °C. DMSO was removed under vacuum, and the residue was mixed with water. The precipitate was collected by filtration and vacuum dried to obtain 0.6 g (59% yield) of crude product 3-(5-{4-[(1-carbamoyl-1-methylethyl)amino]-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1] tert-butyl octane-8-carboxylate. LCMS: [C 30 H 34 N 10 [O3S], Expected mass = 614.7, Observed mass = 615.8 [M+H] + .

[0536] Step 2: The crude product 3-(5-{4-[(1-carbamoyl-1-methylethyl)amino]-6-{3-cyanopyrrolo[1,2- b [3.2.1]pyridazin-7-ylpyridin-3-yl-1,3,4-thiadiazol-2-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.6 g, 0.56 mmol, 1.0 equivalent) was suspended in anhydrous dichloromethane (11.13 ml, 0.05 M), followed by the addition of anhydrous pyridine (0.359 ml, 4.451 mmol, 8.0 equivalent). Trifluoroacetic anhydride (0.351 g, 1.67 mmol, 3.0 equivalent) was added to the resulting suspension, and the reaction mixture was stirred at room temperature for 30 minutes. The reaction mixture was then concentrated under vacuum, dissolved in a minimal amount of DCM, and purified twice by FC using 0-7% DCM-IPA as the mobile phase, followed by 0-30% DCM-ACN as the mobile phase, to give 0.31 g (93% yield) of a yellow solid of 3-(5-{4-[(1-cyano-1-methylethyl)amino]-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1] tert-butyl octane-8-carboxylate. LCMS: [C30 H 32 N 10 [O2S], Expected mass = 596.7, Observed mass = 597.9 [M+H] + . 1 H NMR (400MHz, DMSO- d 6) δ 9.07 (s, 1H), 8.88 (d, J = 2.2Hz, 1H), 8.71 (d, J = 2.2Hz, 1H), 8.69 (s, 1H), 8.65 (s, 1H), 7.90 (d, J = 4.8Hz, 1H), 7.16 (d, J = 4.8Hz, 1H), 4.29 (s, 2H), 3.71 (d, J = 11.9Hz, 2H), 3.39 (d, J =11.3Hz, 2H), 1.92 (s, 6H), 1.75 (d, J = 7.4Hz, 4H), 1.45 (s, 9H).

[0537] Step 3: Add 3-(5-{4-[(1-cyano-1-methylethyl)amino]-6-{3-cyanopyrrolo[1,2- b [[3.2.1]pyridazin-7-yl]pyridin-3-yl]-1,3,4-thiadiazol-2-yl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (0.31 g, 0.52 mmol, 1.0 equivalent) was dissolved in anhydrous DCM (5.2 ml, 0.1 M), followed by dissolution in TFA (1.185 g, 10.39 mmol, 20.0 equivalent). The resulting mixture was stirred at room temperature for 4 hours, and then concentrated under vacuum. The residue was ground and sonicated with diethyl ether to obtain a yellow precipitate. The precipitate was collected by filtration and vacuum dried overnight to give 0.255 g (76% yield) of a yellow solid 7-{4-[(1-cyano-1-methylethyl)amino]-5-(5-{3,8-diazabicyclo[3.2.1]oct-3-yl}-1,3,4-thiadiazol-2-yl)pyridin-2-yl}pyrrolo[1,2- b [Pyridazine-3-carboxynitrile. LCMS: [C] 25 H 24 N 10 [S], Expected mass = 496.6, Observed mass = 497.8 [M+H] + . 1 H NMR (400MHz, DMSO- d6)δ 9.27 - 9.09 (m, 2H), 9.08 (s, 1H), 8.90 (d, J = 2.2Hz, 1H), 8.73 (d, J =2.2Hz, 1H), 8.70 (s, 1H), 8.69 (s, 1H), 7.91 (d, J = 4.8Hz, 1H), 7.17 (d, J =4.8Hz, 1H), 4.25 - 4.18 (m, 2H), 3.93 - 3.80 (m, 2H), 3.67 - 3.57 (m, 2H), 2.07 - 1.95 (m, 4H), 1.93 (s, 6H).

[0538] Intermediate AY: 7-[5-(5-{3-oxa-7,9-diazabicyclo[3.3.1]nonane-7-yl}-1,3,4-thiadi] (-2-yl)-4-[(oxan-4-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxylonitrile; 2x trifluoroacetate

[0539]

[0540] Step 1: Add tert-butyl 3-oxa-7,9-diazabicyclo[3.3.1]nonane-9-carboxylate (0.55 g, 2.41 mmol) to a solution of n-butanol (4.82 mL, 0.5 M) containing 2-bromo-1,3,4-thiadiazole (0.99 g, 6.02 mmol) and DIPEA (1.65 mL, 9.64 mmol). Stir the reaction mixture at 120 °C for 1 hour. Remove volatiles under vacuum, and transfer the residue to a separatory funnel using a mixture of EtOAc (50 mL) and H2O (100 mL), followed by extraction with EtOAc (5 × 50 mL). Dry the combined organic layers over Na2SO4, filter, and concentrate under vacuum. The residue was purified by silica gel rapid chromatography using 0 to 80% ACN / DCM to give 0.467 g (62% yield) of tert-butyl 7-(1,3,4-thiadiazol-2-yl)-3-oxa-7,9-diazabicyclo[3.3.1]nonane-9-carboxylate as a red solid. LCMS: C 13 H 20 The theoretical value of N4O3S is 312.4, and the observed value is... m / z = 313.0 [M+H] + . 1 H NMR (300MHz, DMSO- d 6) δ 8.75 (s, 1H), 4.01 (d, J =9.6Hz, 2H), 3.97 - 3.84 (m, 4H), 3.62 (dt, J = 11.5, 2.5Hz, 2H), 3.44 (d,J =12.9Hz, 2H), 1.44 (s, 9H).

[0541] Step 2: Add 7-(1,3,4-thiadiazol-2-yl)-3-oxa-7,9-diazabicyclo[3.3.1]nonane-9-carboxylate (0.312 g, 0.959 mmol), CuI (0.037 g, 0.19 mmol), Xantphos (0.111 g, 0.19 mmol), and Cs₂CO₃ (1.25 g, 3.84 mmol) to a suspension of 7-{5-bromo-4-[(oxan-4-yl)amino]pyridin-2-yl}pyrrolo[1,2-b]pyridazin-3-carboxylate (0.42 g, 1.06 mmol) in dioxane (32.0 mL, 0.03 M). Degas the reaction mixture with argon for 15 min, then add Pd(OAc)₂ (0.022 g, 0.096 mmol). The reaction mixture was microwaved and stirred at 130°C for 2 hours. It was then cooled to room temperature and additional Xantphos (0.111 g, 0.19 mmol), Cs₂CO₃ (1.25 g, 3.84 mmol), CuI (0.037 g, 0.19 mmol), and Pd(OAc)₂ (0.022 g, 0.096 mmol) were added. The mixture was microwaved and stirred at 130°C for another 2 hours. The evaporation was evaporated under vacuum. The residue was purified by silica gel rapid chromatography, eluting with 0 to 100% MeCN / DCM. The resulting semi-pure product was repurified by reversed-phase rapid chromatography, eluting with MeCN / water (5% to 75% MeCN), to give 0.09 g (15% yield) of 0-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3-oxa-7,9-diazabicyclo[3.3.1]nonane-9-carboxylic acid tert-butyl ester as a yellow solid. LCMS: C 31 H 35 The theoretical value of N9O4S is 629.7, and the observed value is... m / z = 630.2[M+H] + . 1 H NMR (300MHz, DMSO- d 6) δ 8.85 (d, J = 2.3Hz, 1H), 8.77 (d, J = 2.3Hz,1H), 8.70 (s, 1H), 8.51 (s, 1H), 8.29 (s, 1H), 7.84 (d, J= 4.8Hz, 1H), 7.13(d, J = 4.8Hz, 1H), 4.13 - 3.75 (m, 11H), 3.60 (dt, J = 20.0, 10.5Hz, 8H), 2.12 (d, J = 15.5Hz, 3H), 1.58 (d, J = 10.0Hz, 3H).

[0542] Step 3: Add trifluoroacetic acid (0.978 g, 8.58 mmol) to a solution of 7-[5-(6-{3-cyanopyrrolo[1,2-b]pyridazin-7-yl}-4-[(oxan-4-yl)amino]pyridin-3-yl)-1,3,4-thiadiazol-2-yl]-3-oxa-7,9-diazabicyclo[3.3.1]nonane-9-carboxylic acid tert-butyl ester (0.09 g, 0.143 mmol) in DCM (14.3 mL, 0.01 M). Stir the reaction mixture overnight at room temperature. Remove volatiles under vacuum. The crude product was ground and dried with Et2O (4 × 20 mL) to give 0.08 g (83% yield) of a yellow solid of 7-[5-(5-{3-oxa-7,9-diazabicyclo[3.3.1]nonane-7-yl}-1,3,4-thiadiazol-2-yl)-4-[(oxapan-4-yl)amino]pyridin-2-yl]pyrrolo[1,2-b]pyridazine-3-carboxynitrile; 2x trifluoroacetate. LCMS: C 26 H 27 The theoretical value of N9O2S is 529.2, and the observed value is... m / z = 530.3 [M+H] + Method: LCMS2-036-5-80-80-7-1-25-UV-Rot, RT = 2.81 min, purity: 95.71% (254nm). 1 H NMR (300MHz, DMSO-) d 6) δ 8.99 (d, J = 2.2Hz, 1H), 8.87 (d, J = 2.2Hz, 1H), 8.62(s, 1H), 8.14 - 8.04 (m, 2H), 7.25 (d, J = 5.0Hz, 1H), 4.32 (d, J = 13.9Hz, 2H), 4.12 (d, J= 12.5Hz, 3H), 4.03 - 3.83 (m, 6H), 3.67 - 3.54 (m, 2H), 2.57(d, J = 5.5Hz, 4H), 2.10 (t, J = 6.8Hz, 2H), 1.72 - 1.57 (m, 2H).

[0543] B. Synthesis of LHM structural units

[0544] HA-1: 1-(5-(2,6-dioxopiperidin-3-yl)pyridin-2-yl)piperidin-4-carboxaldehyde

[0545]

[0546] Step 1: Under a nitrogen inert atmosphere, 2,6-dichloropyridine (150.00 g, 1013.58 mmol, 1.00 equivalent), dimethylformamide (3 L), and NaH (272.00 g, 11334 mmol, 11.18 equivalent, 65%) were added to a 5-L 4-necked round-bottom flask. Then, BnOH (329.50 g, 3050 mmol, 3.01 equivalent) was added dropwise with stirring at 0 °C. The resulting solution was stirred at 80 °C for 4 hours. The reaction mixture was cooled. The reaction mixture was then quenched by adding 7 L of water / ice. The solid was collected by filtration and concentrated. This yielded 276 g (93.46%) of 2,6-bis(benzyloxy)pyridine as a gray solid. LCMS: (ES, m / z): [M+1] + =292; T=1.48 minutes.

[0547] Step 2: Under a nitrogen-inert atmosphere, 2,6-bis(benzyloxy)pyridine (276.00 g, 947.3 mmol, 1.00 equivalent), CH3CN (2.76 L), and K2CO3 (445.00 g, 3196.54 mmol, 3.37 equivalent) were added dropwise to a 3-L 4-necked round-bottom flask. Then, Br2 (151.70 g, 949.26 mmol, 1.00 equivalent) was added dropwise at 0 °C. The resulting solution was stirred at room temperature for 4 hours. The resulting reaction mixture was concentrated. The residue was loaded onto a silica gel column containing ethyl acetate / petroleum ether (10%). This yielded 253 g (72.13%) of 2,6-bis(benzyloxy)-3-bromopyridine as a white solid. LCMS: [M+1] + =370.

[0548] Step 3: Add 2,6-bis(benzyloxy)-3-bromopyridine (253.00 g, 683.32 mmol, 1.00 equivalent), dioxane (2.53 L), bis(pinacol)diboron (261.00 g, 1027.80 mmol, 1.50 equivalent), potassium acetate (134.00 g, 1365.36 mmol, 2.00 equivalent), and Pd(dppf)Cl2 (25.10 g, 34.29 mmol, 0.05 equivalent) to a 3-L 4-necked round-bottom flask purged and maintained under an inert nitrogen atmosphere. Stir the resulting solution overnight at 100 °C. Cool the reaction mixture. Concentrate the resulting mixture and load it onto a silica gel column containing ethyl acetate / petroleum ether (15%). This yielded 200 g (70.14%) of 2,6-bis(benzyloxy)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyridine as a white solid.

[0549] Step 4: Add 2-fluoro-5-iodopyridine (200.00 g, 896.90 mmol, 1.00 equivalent), DMSO (2.00 L), piperidin-4-ylmethanol (128.90 g, 1119.15 mmol, 1.25 equivalent), and DIEA (347.00 g, 2684.86 mmol, 3.00 equivalent) to a 3-L 4-necked round-bottom flask purged and maintained under an inert nitrogen atmosphere. Stir the resulting solution at 90 °C for 3 days. Cool the reaction mixture. Extract the resulting mixture with 2 × 2 L of EA and combine the organic layers. Wash the resulting mixture with 3 × 2 L of brine. Concentrate the resulting mixture. Apply the residue to a silica gel column containing ethyl acetate / petroleum ether (35%). This yields 182 g (63.78%) of a yellow oily substance of [1-(5-iodopyridine-2-yl)piperidin-4-yl]methanol. LCMS: [M+1] + =319.

[0550] Step 5: Add [1-(5-iodopyridin-2-yl)piperidin-4-yl]methanol (182.00 g, 572.04 mmol, 1.00 equivalent), tetrahydrofuran (1.82 L), water (364.00 mL), 2,6-bis(benzyloxy)-3-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)pyridine (298.40 g, 715.05 mmol, 1.25 equivalent), K₂CO₃ (157.90 g, 1134.23 mmol, 1.98 equivalent), and tetra(triphenylphosphine)palladium(0) (66.00 g, 57.11 mmol, 0.10 equivalent) to a 3-L 4-necked round-bottom flask purged and maintained under an inert nitrogen atmosphere. Stir the resulting solution overnight at 90 °C. Cool the reaction mixture. The resulting mixture was extracted with 2 × 3 L of EA, and the organic layer was washed with 3 × 3 L of brine. The combined organic layers were concentrated. The residue was loaded onto a silica gel column containing ethyl acetate / petroleum ether (85%). This yielded 140 g (50.82%) of [1-[2',6'-bis(benzyloxy)-[3,3'-bipyridine]-6-yl]piperidin-4-yl]methanol as a green solid. LCMS: [M+1] + =482;

[0551] Step 6: Add [1-[2',6'-bis(benzyloxy)-[3,3'-bipyridine]-6-yl]piperidin-4-yl]methanol (35.00 g, 72.67 mmol, 1.00 equivalent), tetrahydrofuran (120 mL), and Pd / C (10.00 g, 10%) to a 2-L round-bottom flask. Stir the resulting solution overnight under a hydrogen atmosphere (4 atm). Then filter the Pd / C, followed by adding another 10 g of Pd / C (10%), and stir again overnight. Repeat the filtration / addition sequence three times. Filter the solids. Concentrate the resulting filtrate and wash with 3 × 100 mL EA, which yields 64 g of crude product. Use 8 g of crude product directly for the next step, and further purify the remaining 56 g of crude product by rapid chromatography. This yielded 45g of a yellow solid, 6'-[4-(hydroxymethyl)piperidin-1-yl]-1,3-dihydro-[3,3'-bipyridine]-2,6-dione.

[0552] LCMS: [M+1] + =304. 1 H-NMR: (300 MHz, DMSO- d 6 , ppm ):δ10.79 (s, 1H), 7.93 (d, J = 2.3Hz, 1H), 7.35 (dd, J= 8.8, 2.5Hz, 1H), 6.79 (d, J = 8.8Hz, 1H), 4.45 (t, J = 5.1Hz, 1H), 4.27 (d, J = 12.9Hz, 2H), 3.72 (dd, J = 12.0, 4.9Hz, 1H), 3.27 (t, J = 5.1Hz, 2H), 2.82-2.59 (m, 3H), 2.58-2.43 (m, 1H), 2.17 (qd, J = 12.5, 4.4Hz, 1H), 1.98 (dq, J = 8.5, 4.7Hz, 1H), 1.71 (d, J = 13.3Hz,2H), 1.60 (br, 1H), 1.11 (qd, J = 11.9, 3.8Hz, 2H).

[0553] Step 7: Under a nitrogen atmosphere, add 3-[6-[4-(hydroxymethyl)piperidin-1-yl]pyridin-3-yl]piperidin-2,6-dione (8.00 g, 26.37 mmol, 1.00 equivalent) and DCM (400.00 mL) to a 1 L 3-necked round-bottom flask. Then add Dysmartin periodide (12.30 g, 31.59 mmol, 1.20 equivalent) at 0 °C. Stir the resulting solution at 0 °C for 2 hours. Filter the reaction mixture, wash the filtrate with brine (200 mL), dry to Na₂SO₄, concentrate under vacuum, and purify by silica gel column chromatography with DCM / EA (3:2). Load the residue onto a silica gel column containing ethyl acetate / petroleum ether (15%). This yielded 5 g (62.92%) of a gray solid, 1-[5-(2,6-dioxopiperidin-3-yl)pyridin-2-yl]piperidine-4-carboxaldehyde (HA-1). LCMS: (ES, m / z): [M+1] + = 302. 1 H-NMR: (300 MHz, DMSO- d 6 , ppm): δ10.80 (s, 1H), 9.62 (s, 1H), 7.95 (d, J = 2.5Hz, 1H), 7.39 (dd, J = 8.9, 2.5Hz, 1H), 6.83(d, J= 8.8Hz, 1H), 4.12 (dd, J = 13.1, 4.2Hz, 2H), 3.73 (dd, J = 12.0,4.9Hz, 1H), 3.10-2.95 (m, 2H), 2.64 (tdd, J = 24.6, 11.1, 4.8Hz, 2H), 2.18(qd, J = 12.4, 4.4Hz, 1H), 2.03-1.93 (m, 1H), 1.89 (dd, J = 13.2, 3.6Hz, 3H), 1.57-1.39 (m, 2H).

[0554] HA-2: Racemic-(R)-3-(6-(piperidin-4-yl)pyridin-3-yl)piperidin-2,6-dione

[0555]

[0556] Step 1: Add tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylate (14.36 g, 46.43 mmol, 1.10 equivalent), a solution of Na₂CO₃ (6.71 g, 63.32 mmol, 1.5 equivalent) in H₂O (10 mL), and Pd(PPh₃)₄ (1.46 g, 1.27 mmol, 0.03 equivalent) to a mixture of 2,5-dibromopyridine (10 g, 42.21 mmol, 1 equivalent) in 1,4-dioxane (100 mL). Stir the resulting mixture overnight at 100 °C under a nitrogen atmosphere. Concentrate the mixture under vacuum. The residue was purified by silica gel column chromatography with PE / EA (2 / 1) elution to give tert-butyl 5-bromo-3',6'-dihydro-2'H-[2,4'-bipyridine]-1'-carboxylic acid (10 g, 69.83%) as a yellow solid. (C) 15 H 21 BrN2O2) [M+1 + The calculated LCMS (ESI) value is 339.1; the measured value is 339.1.

[0557] Step 2: To a mixture of tert-butyl 4-(5-bromopyridin-2-yl)piperidin-1-carboxylate (1 g, 2.93 mmol, 1 equivalent) in THF (9 mL), add a solution of 2,6-bis(benzyloxy)pyridin-3-ylboronic acid (1.18 g, 3.52 mmol, 1.2 equivalent) and K₂CO₃ (0.81 g, 5.86 mmol, 2 equivalent) in H₂O (3 mL) and Pd(PPh₃)₄ (0.34 g, 0.29 mmol, 0.1 equivalent). The resulting mixture was stirred overnight at 110 °C under a nitrogen atmosphere. The mixture was then concentrated under vacuum. The residue was purified by silica gel column chromatography with PE / EA (5 / 1) elution to give tert-butyl 5-[2,6-bis(benzyloxy)pyridin-3-yl]-3',6'-dihydro-2'H-[2,4'-bipyridine]-1'-carboxylic acid (1.3 g, 80.71%) as a white solid. (C) 34 H 35 N3O4) [M+1 + The calculated LCMS (ESI) value is 550.3; the measured value is 550.3.

[0558] Step 3: Pd / C (1 g) was added to a mixture of 5-[2,6-bis(benzyloxy)pyridin-3-yl]-3',6'-dihydro-2'H-[2,4'-bipyridine]-1'-carboxylic acid tert-butyl ester (1.3 g, 2.37 mmol, 1 equivalent) in THF (15 mL). The reaction mixture was stirred at room temperature for 5 hours under a hydrogen atmosphere. The reaction mixture was filtered and then concentrated under reduced pressure. The resulting residue was purified by C18 reversed-phase column chromatography with CH3CN / H2O (1 / 1) to give 4-[5-(2,6-dioxopiperidin-3-yl)pyridin-2-yl]piperidin-1-carboxylic acid tert-butyl ester (0.35 g, 39.63%) as a brown solid. (C 20 H 27 N3O4) [M+1 + The calculated LCMS (ESI) value is 374.2; the measured value is 374.0.

[0559] Step 4: The mixture of tert-butyl 4-[5-(2,6-dioxadiazin-3-yl)pyridin-2-yl]piperidine-1-carboxylate (350 mg, 0.94 mmol, 1 equivalent) in HCl / dioxane (15 mL, 4 M) was stirred at room temperature for 1 hour. The resulting mixture was concentrated under vacuum. This yielded racemic (3R)-3-[6-(piperidine-4-yl)pyridin-3-yl]piperidine-2,6-dione hydrochloride (HA-2) (290 mg, 99.88%) as a pink solid. 15 H 19 N3O2) [M+1 +The calculated LCMS (ESI) value is 274.2; the measured value is 274.1. 1 H NMR (400MHz, DMSO- d 6 ) δ 10.98 (s, 1H), 9.19 (s, 1H), 9.09 (s, 1H), 8.68 - 8.63 (m, 1H), 8.22 - 8.15 (m, 1H), 7.73 - 7.66 (m, 1H), 4.20 - 4.12(m, 1H), 3.44 - 3.36 (m, 2H), 3.32 (s, 1H), 3.09 - 3.02 (m, 1H), 3.02 - 2.96(m, 1H), 2.80 - 2.67 (m, 1H), 2.64 - 2.55 (m, 1H), 2.43 - 2.27 (m, 1H), 2.18- 2.11 (m, 2H), 2.06 (s, 2H), 2.11 - 1.96 (m, 1H).

[0560] HA-3: 1-(4-(2,6-dioxopiperidin-3-yl)-2-fluorophenyl)piperidin-4-carboxaldehyde

[0561]

[0562] Step 1: Under N2, L-proline (17.4 g, 132 mmol, 0.400 equivalent), K2CO3 (91.8 g, 664 mmol, 2.00 equivalent), and CuI (12.6 g, 66.4 mmol, 0.200 equivalent) were added to a solution of 2-fluoro-4-bromo-iodobenzene (42.1 g, 365 mmol, 1.10 equivalent) and piperidin-4-ylmethanol (100 g, 332 mmol, 1.00 equivalent) in DMSO (1000 mL). The reaction mixture was stirred at 90 °C for 12 hours. The reaction mixture was cooled to 20 °C and poured into a saturated NH4Cl solution (1000 mL). The product was extracted with ethyl acetate (1000 mL × 3), and the combined organic layers were washed with brine (1000 mL), dried over Na2SO4, filtered, and concentrated. The residue was subjected to column chromatography (SiO2, petroleum ether / ethyl acetate = 10 / 1 to 0 / 1, R...) f Purification was performed using a concentration of 0.55 g / mL. The desired product was obtained as a yellow solid (10.7 g, 35.6 mmol, 10.7% yield). LCMS: m / z = 290.0 (M+H) + .

[0563] Step 2: Under N2, add Pd(dppf)Cl2 to a solution of (1-(4-bromo-2-fluorophenyl)piperidin-4-yl)methanol (11.6 g, 38.6 mmol, 1.00 equivalent), 2,6-bis(benzyloxy)-3-(4,4,5-trimethyl-1,3,2-dioxane-2-yl)pyridine (17.7 g, 42.4 mmol, 1.10 equivalent), K2CO3 (16.0 g, 115 mmol, 3.00 equivalent) in dioxane (116 mL) and H2O (23 mL). CH2Cl2 (3.15 g, 3.86 mmol, 0.100 equivalent). The reaction mixture was then stirred at 110 °C for 12 hours. The mixture was cooled to 25 °C. The reaction mixture was then poured into H2O (300 mL) and extracted with EtOAc (200 mL × 3). The combined organic layers were washed with brine (200 mL), dried over Na2SO4, and concentrated. The crude product was subjected to MPLC (SiO2, petroleum ether / ethyl acetate = 100 / 1 to 5 / 1) (petroleum ether / ethyl acetate = 1 / 1, R f Purification was performed (m = 0.5). Compound 11 was given as a pale yellow solid (10.7 g, 20.5 mmol, 53.2% yield). LCMS: m / z = 499.4 (M+H) + .

[0564] Step 3: Under N2, add AcOH (4.19 g, 69.8 mmol, 3.99 mL, 3.00 equivalent), Pd / C (2.90 g, 10% purity), and Pd(OH)2 (3.01 g, 4.29 mmol, 20% purity) to a solution of (1-(4-(2,6-bis(benzyloxy)pyridin-3-yl)-2-fluorophenyl)piperidin-4-yl)methanol (11.6 g, 23.2 mmol, 1.00 equivalent) in THF (120 mL) and EtOH (120 mL). Degas the suspension under vacuum and purge several times with H2. Stir the mixture at 80 °C for 12 hours under H2 (50 psi). Cool the reaction mixture to 20 °C and filter. Concentrate the filtrate. Use the crude product for the next step without purification. The desired product (8.40 g, crude product) is obtained as a yellow solid. LCMS: m / z = 321.2 (M+H) + .

[0565] Step 4: DMP (22.2 g, 52.4 mmol, 16.2 mL, 2.00 equivalent) was added in portions to a solution of 3-(3-fluoro-4-(4-(hydroxymethyl)piperidin-1-yl)phenyl)piperidin-2,6-dione (8.40 g, 26.2 mmol, 1.00 equivalent) in DMSO (90.0 mL). The reaction mixture was stirred at 25 °C for 12 h. The pH of the reaction mixture was adjusted to pH 10 with a saturated aqueous solution of Na₂CO₃, and the aqueous layer was extracted with ethyl acetate (400 mL × 4). The combined organic layers were washed with Na₂S₂O₃ solution (500 mL × 2) and brine (1000 mL), dried over Na₂SO₄, filtered, and concentrated under vacuum. The crude product was milled at 25 °C with ethyl acetate (100 mL) for 12 h. HA-3 (2.50 g, 7.60 mmol, 28.9% yield) was obtained as a yellow solid. LCMS: m / z = 317.1 (MH) + . 1 H NMR (400MHz, DMSO- d 6 ) δ 10.8 (s, 1H), 9.64 (s, 1H), 7.06 -6.90 (s, 3H), 3.83 - 3.76 (m, 1H), 3.29 - 3.24 (m, 2H), 2.76 (t, J = 10.0Hz,2H), 2.69 - 2.60 (m, 1H), 2.48 - 2.41 (m, 2H), 2.24 - 2.13 (m, 1H), 2.04 -1.91 (m, 3H), 1.71 - 1.58 (m, 2H).

[0566] HA-4: 1-(4-(2,6-dioxopiperidin-3-yl)-3-fluorophenyl)piperidin-4-carboxaldehyde

[0567]

[0568] HA-4 was synthesized using the same procedure as HA-3, except that in step 1, 4-bromo-2-fluoro-1-iodobenzene was replaced with 1-bromo-2-fluoro-4-iodobenzene, yielding the title compound. LCMS: m / z = 317.1 (MH) + . 1 H NMR: (400MHz, DMSO- d 6 ) δ10.79 (s, 1H), 9.62 (s, 1H), 7.07 (t, J= 8.8Hz, 1H), 6.77 - 6.69 (m, 2H), 3.91 - 3.84 (m, 1H), 3.67 - 3.59 (m, 2H), 2.91 - 2.81 (m, 2H), 2.76 - 2.65(m, 1H), 2.56 - 2.52 (m, 1H), 2.49 - 2.45 (m, 1H), 2.20 - 2.07 (m, 1H), 1.97 - 1.86 (m, 3H), 1.61 - 1.49 (m, 2H).

[0569] HA-5: Racemic-(R)-3-(1,2,3,4-tetrahydroisoquinoline-6-yl)piperidine-2,6-dione

[0570]

[0571] Step 1: Add tert-butyl 6-bromo-3,4-dihydro-1H-isoquinoline-2-carboxylate (1000.00 mg, 3.20 mmol), 2,6-bis(benzyloxy)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)pyridine (1470.31 mg, 3.52 mmol), tripotassium phosphate (2.04 g, 9.61 mmol), and Pd(dppf)Cl2 to a 40 mL vial. DCM (0.26 g, 0.32 mmol), dioxane (7.00 mL), and water (2.50 mL) were used. The reaction mixture was degassed with nitrogen for 15 min and then stirred at 90 °C for 16 h. The reaction mixture was then diluted with water and EtOAc and filtered through diatomaceous earth. The product was extracted with EtOAc (3×), dried over MgSO4, and then concentrated. The resulting residue was purified by column chromatography (80 g silica, 0-25% EtOAc / hexane) to give tert-butyl 6-[2,6-bis(benzyloxy)pyridin-3-yl]-3,4-dihydro-1H-isoquinoline-2-carboxylate (1.48 g, 88%) as a colorless oil. LCMS C 33 H 34 Theoretical value of N₂O₄: 522.3, measured value: m / z = 523.3 [M+H] + .

[0572] Step 2: Add tert-butyl 6-[2,6-bis(benzyloxy)pyridin-3-yl]-3,4-dihydro-1H-isoquinoline-2-carboxylate (1480.00 mg, 2.83 mmol), Pd / C (700.00 mg), THF (10.00 mL), and EtOH (10.00 mL) to a 40 mL vial. Bubble the reaction mixture with hydrogen for 5 minutes, then stir the mixture under a hydrogen atmosphere (balloon) for 16 hours. Filter the reaction mixture through diatomaceous earth and concentrate. Purify the residue by column chromatography (40 g silica, 0-10% MeOH / DCM) to give racemic 6-[(3R)-2,6-dioxopiperidin-3-yl]-3,4-dihydro-1H-isoquinoline-2-carboxylate (852 mg, 87%) as a white solid. LCMS C 19 H 24 Theoretical value of N₂O₄: 344.2, measured value: m / z = 345.2 [M+H] + .

[0573] Step 3: Racemic 6-[(3R)-2,6-dioxadiazin-3-yl]-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester (852.00 mg, 2.47 mmol) and DCM (2.00 mL) were added to a 40 mL vial. A solution of 4 M hydrogen chloride in dioxane (6.18 mL, 0.90 g, 24.74 mmol) was added dropwise to the reaction mixture. After 1 hour, the reaction mixture was concentrated to give the title compound as a white solid (707 mg, quantitative yield). LCMS C 14 H 16 Theoretical value of N2O2: 244.1, measured value: m / z = 245.0 [M+H] + .

[0574] HA-6: 1-{4-[4-({4-[2-(6,6-dimethyl-1,4,5,7-tetrahydroindazole-3-yl)-1H-indole-5-carbonyl] [[ ...][[[[[[[[[[[[[][[[[[[[[[[][[[[[[[[][[[[[[[][[[[[[[][[[[[][[[[[[[][

[0575]

[0576] Step 1: At room temperature, acrylic acid (22.75 g, 315.77 mmol, 3 equivalents) was added to a mixture of 4-bromo-2-fluoroaniline (20 g, 105.26 mmol, 1 equivalent) and AcOH (80 mL) and H₂SO₄ (1 mL). The resulting mixture was stirred at 100 °C for 2 hours. The resulting mixture was concentrated under reduced pressure. The residue was purified by passing it through a C18 reversed-phase column with ACN / H₂O (1 / 4). This gave 3-[(4-bromo-2-fluorophenyl)amino]propionic acid (13 g, 42.41%) as a grayish-white solid. (C₉H₉BrFNO₂) [M+1] +The calculated LCMS (ESI) value is 262.0; the measured value is 262.0.

[0577] Step 2: At 0°C, SOCl2 (54 mL) was added to a mixture of 3-[(4-bromo-2-fluorophenyl)amino]propionic acid (13 g, 49.6 mmol, 1 equivalent) and MeOH (30 mL). The resulting mixture was stirred at room temperature for 2 hours. The mixture was then concentrated under reduced pressure. This yielded methyl 3-[(4-bromo-2-fluorophenyl)amino]propionic acid (9 g, crude product) as a brown oil. (C) 10 H 11 BrFNO2) [M+1 + The calculated LCMS (ESI) value is 276.0; the measured value is 276.0.

[0578] Step 3: At room temperature, potassium cyanate (7.93 g, 97.79 mmol, 3 equivalents) was added to a mixture of methyl 3-[(4-bromo-2-fluorophenyl)amino]propionate (9 g, 32.6 mmol, 1 equivalent) in AcOH (40 mL) and DCM (40 mL). The resulting mixture was stirred at room temperature for 3 hours. The mixture was extracted with EtOAc (3 × 30 mL). The combined organic layers were washed with water (3 × 10 mL) and dried over anhydrous Na₂SO₄. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by passing it through a C18 reversed-phase column with ACN / H₂O (3 / 7). This gave methyl 3-[(4-bromo-2-fluorophenyl)(carbamoyl)amino]propionate (3.5 g, 30.28%) as a white solid. (C 11 H 12 BrFN2O3) [M+1 + The calculated LCMS (ESI) value is 319.0; the measured value is 319.0.

[0579] Step 4: At room temperature, potassium trimethylsilanoate (3.52 g, 27.42 mmol, 2.5 equivalents) was added to a mixture of methyl 3-[(4-bromo-2-fluorophenyl)(carbamoyl)amino]propionate (3.5 g, 10.97 mmol, 1 equivalent) and THF (20 mL). The resulting mixture was stirred at room temperature for 1 hour. The mixture was extracted with EtOAc (3 × 20 mL). The combined organic layers were washed with water (3 × 10 mL) and dried over anhydrous Na₂SO₄. After filtration, the filtrate was concentrated under reduced pressure to give 1-(4-bromo-2-fluorophenyl)-1,3-diazine-2,4-dione (2 g, crude) as a white solid. (C 10 H8BrFN2O2) [M+1 + The calculated LCMS (ESI) value is 287.0; the measured value is 287.0.

[0580] Step 5: Add piperidin-4-ylmethanol (2.29 g, 19.85 mmol, 3 equivalents), Pd(OAc)2 (0.21 g, 0.94 mmol, 0.1 equivalents), Cs2CO3 (9.19 g, 28.22 mmol, 3 equivalents), and t-BuXPhos (0.80 g, 1.88 mmol, 0.2 equivalents) to a mixture of 1-(4-bromo-2-fluorophenyl)-1,3-diazine-2,4-dione (2.7 g, 9.41 mmol, 1 equivalent) and dioxane (25 mL) to the mixture. Stir the resulting mixture overnight at 90 °C under a nitrogen atmosphere. The residue was purified by passing it through a C18 reversed-phase column with ACN / H2O (1 / 2) to give 1-{2-fluoro-4-[4-(hydroxymethyl)piperidin-1-yl]phenyl}-1,3-diazine-2,4-dione (324 mg, 10.58%) as a gray solid. 16 H 20 FN3O3) [M+1 + The calculated LMS (ESI) value is 322.1; the measured value is 322.2. 1 H NMR (400MHz, DMSO- d 6) δ 7.93 (s, 1H), 7.22 - 7.13 (m,1H), 6.84 - 6.72 (m, 1H), 6.01 (s, 2H), 3.79 - 3.72 (m, 2H), 3.66 - 3.58 (m,2H), 3.28 (s, 2H), 2.75 - 2.65 (m, 4H), 1.76 - 1.69 (m, 2H), 1.56 - 1.52 (m,1H), 1.31 - 1.03 (m, 2H).

[0581] Step 6: At 0 °C, Dysmart (197 mg, 0.47 mmol, 1.5 equivalent) was added fractionally to a mixture of 1-{2-fluoro-4-[4-(hydroxymethyl)piperidin-1-yl]phenyl}-1,3-diazine-2,4-dione (100 mg, 0.31 mmol, 1 equivalent) in DCM (5 mL). The resulting mixture was stirred at 0 °C for 2 hours. The resulting mixture was concentrated under reduced pressure. The resulting mixture was purified by passing it through a C18 reversed-phase column with ACN / H2O (1 / 2). This gave the title compound (36 mg, 37.3%) as a brown solid. (C 16 H 18 FN3O3) [M+1 + The calculated LCMS (ESI) value is 320.1; the measured value is 320.2.

[0582] HA-7: 1-(4-(2,6-dioxopiperidin-3-yl)phenyl)piperidin-4-carboxaldehyde

[0583]

[0584] Step 1: At 20°C under N2, piperidin-4-ylmethanol (26.4 g, 229 mmol, 1.30 equivalent), K3PO4 (75.0 g, 353 mmol, 2.00 equivalent), CuI (6.73 g, 35.3 mmol, 0.200 equivalent), and L-proline (4.64 g, 35.3 mmol, 0.200 equivalent) were added to a solution of 1-bromo-4-iodobenzene (50.0 g, 176 mmol, 1.00 equivalent) in DMSO (250 mL). The reaction mixture was stirred at 80°C under N2 for 12 hours. The mixture was cooled to 20°C and poured into water (1.00 L). The mixture was stirred for 0.5 hours. The mixture was extracted with ethyl acetate (500 mL × 3). The organic layer was washed with a solution of NH3·H2O in H2O (100 mL NH3·H2O in 700 mL H2O) (250 mL × 3). The organic layer was then washed with brine (1000 mL), dried over Na2SO4, filtered, and concentrated. The residue was subjected to column chromatography (SiO2, petroleum ether / ethyl acetate = 20 / 1 to 2 / 1, R...) f Purification was performed using a concentration of 0.30 g / mL. The desired product was obtained as a yellow solid (31.0 g, 87.0 mmol, 49.2% yield). LCMS: m / z = 270.0 (M+H) + .

[0585] Step 2: At 20°C under N2, add K2CO3 (34.9 g, 252 mmol, 3.00 equivalent) and Pd(dppf)Cl2 to a solution of (1-(4-bromophenyl)piperidin-4-yl)methanol (30.0 g, 84.2 mmol, 1.00 equivalent) and 2,6-bis(benzyloxy)-3-(4,4,5-trimethyl-1,3,2-dioxane-2-yl)pyridine (35.1 g, 84.2 mmol, 1.00 equivalent) in dioxane (300 mL) and H2O (60.0 mL). CH2Cl2 (6.88 g, 8.43 mmol, 0.100 equivalent). The reaction mixture was stirred at 110 °C for 12 h under N2. The reaction mixture was cooled to 20 °C and filtered. The filtrate was concentrated. The crude product was purified by recrystallization from MeOH (100 mL) at 20 °C for 30 min. The mixture was filtered, and the filter cake was subjected to column chromatography (SiO2, petroleum ether / ethyl acetate = 10 / 1 to 1 / 1, R...). fPurification was performed using a concentration of 0.30 g / mL. The desired product was obtained as a yellow solid (22.5 g, 44.8 mmol, 53.2% yield). LCMS: m / z = 481.2 (M+H). + .

[0586] Step 3: Under N2, add Pd / C (5.00 g, 39.8 mmol, 1.00 equivalent) and Pd(OH)2 (4.79 g, 34.1 mmol, 8.56e-1 equivalent) to a solution of (1-(4-(2,6-bis(benzyloxy)pyridin-3-yl)phenyl)piperidin-4-yl)methanol (20.0 g, 39.8 mmol, 10% purity, 1.00 equivalent) and AcOH (7.18 g, 119 mmol, 6.84 mL, 3.00 equivalent) in THF (200 mL) and EtOH (200 mL). Degas the suspension under vacuum and purge several times with H2. Stir the mixture at 80 °C for 12 hours under H2 (50 psi). Cool the mixture to 20 °C and filter. Concentrate the filtrate. The crude product was milled at 20°C with petroleum ether / ethyl acetate (5 / 1, 200 mL) for 30 minutes. The desired product (8.00 g, 24.2 mmol, 60.7% yield) was given as a white solid. LCMS: m / z = 303.2 (M+H) + .

[0587] Step 4: At 20°C, Dysmartin periodide (24.1 g, 56.8 mmol, 1.00 equivalent) was slowly added to a solution of 3-(4-(4-(hydroxymethyl)piperidin-1-yl)phenyl)piperidin-2,6-dione (8.60 g, 28.4 mmol, 1.00 equivalent) in DMSO (90.0 mL). The reaction mixture was stirred at 20°C for 12 hours. The mixture was adjusted to pH 10 with saturated Na₂CO₃ aqueous solution, and the aqueous layer was extracted with ethyl acetate (350 mL × 3). The combined organic layers were washed with Na₂S₂O₃ solution (500 mL) and brine (500 mL), dried over Na₂SO₄, and concentrated under vacuum. The crude product was milled at 20°C with ethyl acetate (100 mL) for 30 minutes. HA-7 (7.18 g, 22.8 mmol, 48.1% yield) was given as a grayish-white solid. LCMS: m / z = 299.1 (MH) + . 1 H NMR: (400MHz, DMSO- d 6) δ 11.00 - 10.57 (m, 1H), 9.80 - 9.35(m, 1H), 7.09 - 6.98 (m, 2H), 6.95 - 6.83 (m, 2H), 3.79 - 3.66 (m, 1H), 3.63- 3.49 (m, 2H), 2.89 - 2.72 (m, 2H), 2.70 - 2.59 (m, 1H), 2.48 - 2.38 (m,2H), 2.17 - 1.89 (m, 4H), 1.65 - 1.47 (m, 2H).

[0588] HA-8: racemic-(R)-2-(1-(5-(2,6-dioxopiperidin-3-yl)pyridin-2-yl)piperidin-4-yl)acetic acid

[0589]

[0590] Step 1: Racemic (3R)-3-(6-fluoropyridin-3-yl)piperidin-2,6-dione (1.00 g, 4.80 mmol), tert-butyl 2-(piperidin-4-yl)acetate (1.01 g, 5.04 mmol), DMSO (7.00 mL), and N,N-diisopropylethylamine (3.18 mL, 2.48 g, 19.21 mmol) were added to a 40 mL vial. The reaction mixture was stirred at 130 °C for 16 hours. The reaction mixture was then diluted with EtOAc and brine. The product was extracted with EtOAc (2×). The combined organic layers were washed with brine (3×), dried over MgSO4, and then concentrated. The resulting residue was purified by column chromatography (80 g silica, 0-100% EtOAc / DCM) to obtain racemic 2-(1-{5-[(3R)-2,6-dioxopiperidin-3-yl]pyridin-2-yl}piperidin-4-yl)tert-butyl acetate (456 mg, 25%) as a brown solid. LCMS C 17 H 21 Theoretical N3O4 content: 387.2, measured value: 388.2 [M+H] + .

[0591] Step 2: Racemic 2-(1-{5-[(3R)-2,6-dioxopiperidin-3-yl]pyridin-2-yl}piperidin-4-yl)tert-butyl acetate (456.00 mg, 1.18 mmol) and DCM (5.00 mL) were added to a 40 mL vial. Trifluoroacetic acid (5.00 mL, 7.45 g, 65.34 mmol) was added dropwise to the reaction mixture. After 30 minutes, the reaction mixture was concentrated under reduced pressure. The resulting residue was purified by chromatography (100 g C18 silica, 0-20% MeCN / H2O) to give the title compound (1.04 g, 100%) as a white solid. LCMS C 21 H 29 Theoretical value of N3O4: 331.2, measured value: m / z = 332.2 [M+H] + .

[0592] HA-9: Racemic-1-[5-[(3R)-2,6-dioxopiperidin-3-yl]pyridin-2-yl]piperidin-4-carboxylic acid

[0593]

[0594] Step 1: Add tert-butyl piperidine-4-carboxylate (8.39 g, 45.28 mmol, 1 equivalent) and K₂CO₃ (10.43 g, 75.46 mmol, 2 equivalent) to a mixture of 5-bromo-2-fluoropyridine (6.64 g, 37.73 mmol, 1 equivalent) in DMF (50 mL). Stir the resulting mixture overnight at 90 °C. Extract the mixture with EtOAc (3 × 100 mL). Wash the combined organic layers with water (3 × 50 mL) and dry over anhydrous Na₂SO₄. Filter and concentrate the filtrate under reduced pressure. Purify the residue by silica gel column chromatography, eluting with PE / EtOAc (1 / 1). This yields tert-butyl 1-(5-bromopyridin-2-yl)piperidine-4-carboxylate (10 g, 46.60% yield) as a pale yellow solid. (C 15 H 21 BrN2O2) [M+H] + The calculated LCMS (ESI) value is 341.2; the measured value is 341.2.

[0595] Step 2: Pd(PPh3)4 (0.5 g, 0.43 mmol, 0.1 equivalent) was added to a mixture of tert-butyl 1-(5-bromopyridin-2-yl)piperidin-4-carboxylate (2.40 g, 7.04 mmol, 1.6 equivalent), 2,6-bis(benzyloxy)pyridin-3-ylboronic acid (1.47 g, 4.39 mmol, 1.00 equivalent), and K2CO3 (1.2 g, 8.70 mmol, 2 equivalent) in THF (10 mL) and H2O (10 mL). The resulting mixture was stirred in a microwave at 110 °C for 40 min under nitrogen atmosphere. The mixture was concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE / EtOAc (1 / 1). This yields tert-butyl 1-[2,6-bis(benzyloxy)-[3,3-bipyridine]-6-yl]piperidine-4-carboxylate as a white solid (1.2 g, 49.36% yield). (C) 33 H 35 N3O4) [M+H + The calculated LCMS (ESI) value is 552.3; the measured value is 552.0.

[0596] Step 3: Pd / C (0.9 g) was added to a mixture of 1-[2,6-bis(benzyloxy)-[3,3-bipyridine]-6-yl]piperidine-4-carboxylic acid tert-butyl ester (1.8 g, 3.26 mmol, 1 equivalent) in EtOH (50 mL) and THF (50 mL). The resulting mixture was stirred at room temperature for 3 hours under a hydrogen atmosphere. The resulting mixture was filtered. The filtrate was concentrated under reduced pressure. The residue was purified by C18 reversed-phase column chromatography using CH3CN / H2O (2 / 1). This yielded 1-[5-(2,6-dioxopiperidine-3-yl)pyridin-2-yl]piperidine-4-carboxylic acid tert-butyl ester (390 mg, 28.81% yield) as a yellow solid. (C 20 H 27 N3O4) [M+H + The calculated LCMS (ESI) value is 374.2; the measured value is 374.2.

[0597] Step 4: At 0 °C, TFA (10 mL) was added dropwise to a mixture of tert-butyl 1-[5-(2,6-dioxopiridine-3-yl)pyridin-2-yl]piperidine-4-carboxylic acid (650 mg, 1.74 mmol, 1 equivalent) in DCM (100 mL). The resulting mixture was stirred at 0 °C for 2 hours. The mixture was concentrated under vacuum. The residue was purified by C18 reversed-phase column chromatography using CH3CN / H2O (1 / 1). This yielded racemic 1-[5-[(3R)-2,6-dioxopiridine-3-yl]pyridin-2-yl]piperidine-4-carboxylic acid (540.8 mg, 96.08% yield) as a purple solid. (C16 H 19 N3O4) [M+H + The calculated LCMS (ESI) value is 318.2; the measured value is 318.2. 1 H NMR (300MHz, DMSO- d 6 ) δ 10.91 (s, 1H), 7.97 - 7.73 (m, 2H), 7.30 (d, J = 9.3Hz, 1H), 4.14 - 4.02 (m, 2H), 3.95 - 3.84 (m, 1H), 3.29 - 3.14 (m,2H), 2.76 - 2.48 (m, 3H), 2.36 - 2.16 (m, 1H), 2.02 - 1.88 (m, 3H), 1.70 -1.51 (m, 2H).

[0598] HA-10: Racemic-(R)-3-(6-(piperazin-1-yl)pyridin-3-yl)piperidine-2,6-dione

[0599]

[0600] Step 1: Piperazine-1-carboxylate tert-butyl ester (0.895 g, 4.8 mmol) and 3-(6-fluoropyridin-3-yl)piperidine-2,6-dione (0.5 mg, 2.40 mmol) were combined in DMSO (0.15 M), followed by the addition of N,N-diisopropylethylamine (1.68 mL, 9.61 mmol). The vial was capped and stirred overnight at 110 °C. The reaction mixture was then cooled to room temperature, concentrated on silica gel, and purified by column chromatography (0-100% EtOAc / hexane) to give racemic (R)-4-(5-(2,6-dioxopirin-3-yl)pyridin-2-yl)piperazine-1-carboxylate tert-butyl ester (0.6 g, 67%). LCMS: C 19 H 26 Theoretical value of N4O4: 374.1, measured value: m / z = 375.1 [M+H] + .

[0601] Step 2: Racemic (R)-4-(5-(2,6-dioxopiperidin-3-yl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester was treated with 0.6 mL of HFIP solution (10 mL) of TFA and stirred at room temperature for 5 hours. LCMS showed complete conversion of the starting material. The reaction mixture was concentrated and purified by C18 reversed-phase chromatography to give racemic (R)-3-(6-(piperazine-1-yl)pyridin-3-yl)piperidin-2,6-dione (0.31 g, 71%) as a grayish-white solid.1 H NMR (500MHz, DMSO) δ10.85 (s, 1H), 8.03 (d, J = 2.4Hz, 1H), 7.56 (dq, J = 8.9, 2.1Hz, 1H), 6.98 (dt, J = 9.1, 2.1Hz, 1H), 3.82 (dd, J = 12.4, 4.9Hz, 1H), 3.72 (t, J = 5.2Hz, 4H), 3.2 (t, J = 5.2Hz, 4H), 2.70 (ddd, J = 17.6, 13.3, 5.3Hz, 1H), 2.56 (q,J = 2.8, 1.9Hz, 1H), 2.23 (qd, J = 12.6, 4.2Hz, 1H), 2.08 (s, 1H), 1.98 (dtd,J = 13.3, 5.2, 3.2Hz, 1H). LCMS:C 14 H 18 Theoretical value of N4O2: 274.32, measured value: m / z = 275.1 [M+H] + .

[0602] HA-11: 3-[(3RS)-1-[5-[(3RS&)-2,6-dioxopiperidin-3-yl]pyridin-2-yl]pyrrolidine-3- [By]propionic acid

[0603]

[0604] Step 1: At 0°C under a nitrogen atmosphere, add benzyl 2-(dimethoxyphosphoryl)acetate (28.51 g, 110.4 mmol, 1.1 equivalents) to a mixture of NaH (2.65 g, 110.4 mmol, 1.1 equivalents) and THF (500 mL). Stir the resulting mixture at room temperature under a nitrogen atmosphere for 30 minutes. At 0°C, add tert-butyl 3-formylpyrrolidine-1-carboxylate (20 g, 100.4 mmol, 1 equivalent) to the above mixture. Stir the resulting mixture at room temperature under a nitrogen atmosphere overnight. Extract the aqueous layer with EtOAc (3 × 500 mL). Concentrate the resulting mixture under vacuum. The residue was purified by silica gel column chromatography with PE / EtOAc (1 / 1) elution to give tert-butyl 3-[(1E)-3-(benzyloxy)-3-oxoprop-1-en-1-yl]pyrrolidine-1-carboxylate (31.6 g, 77.89% yield) as a colorless oil. (C) 19 H 25 NO4) [M+H] + The calculated LCMS (ESI) value is 332.1; the measured value is 332.1.

[0605] Step 2: At room temperature, Pd / C (2.04 g) was added to a mixture of tert-butyl 3-[(1E)-3-(benzyloxy)-3-oxoprop-1-en-1-yl]pyrrolidine-1-carboxylate (12.70 g, 38.32 mmol, 1 equivalent) in THF (200 mL). The resulting mixture was stirred overnight at room temperature under a hydrogen atmosphere. The resulting mixture was filtered. The filtrate was concentrated under reduced pressure. This gave 3-[1-(tert-butoxycarbonyl)pyrrolidine-3-yl]propionic acid (3) (9 g, crude) as a grayish-white solid. The crude product was used directly in the next step without further purification. (C) 12 H 21 NO4) [M+1] + The calculated LCMS (ESI) value is 244.1; the measured value is 244.1.

[0606] Step 3: The mixture of 3-[1-(tert-butoxycarbonyl)pyrrolidine-3-yl]propionic acid (9 g, crude) in HCl / dioxane (4 mol / L, 100 mL) was stirred at room temperature for 1 hour. The resulting mixture was concentrated under vacuum. This yielded 5.88 g, crude 3-(pyrrolidine-3-yl)propionic acid as a pink solid. (C7H) 13 N1O2) [M+1 + The calculated LCMS (ESI) value is 144.0; the measured value is 144.2.

[0607] Step 4: At room temperature, K₂CO₃ (8.5 g, 61.07 mmol, 1 equivalent) was added to a mixture of 3-(pyrrolidin-3-yl)propionic acid (5.88 g, 41.07 mmol, 1 equivalent) and 5-bromo-2-fluoropyridine (7.23 g, 41.08 mmol, 1 equivalent) in DMF (30 mL). The resulting mixture was stirred overnight at 80 °C. The mixture was extracted with EtOAc (3 × 100 mL). The combined organic layers were washed with water (3 × 50 mL) and dried over anhydrous Na₂SO₄. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by passing it through a C18 reversed-phase column with CH₃CN / H₂O (1 / 2). This gave 3-[1-(5-bromopyridin-2-yl)pyrrolidin-3-yl]propionic acid (5) (12 g, 89.67% yield) as a crude brown oil. (C 12 H 15 BrN2O2) [M+1 + The calculated LCMS (ESI) value is 299.0; the measured value is 299.0.

[0608] Step 5: At 0°C, (Z)-N,N-diisopropyltert-butoxyformamidinium (24.11 g, 120.4 mmol, 3 equivalents) was added to a mixture of 3-[1-(5-bromopyridin-2-yl)pyrrolidine-3-yl]propionic acid (12 g, 40.11 mmol, 1 equivalent) in DCM (100 mL). The resulting mixture was stirred at room temperature for 3 hours. The mixture was concentrated under vacuum. The residue was purified by silica gel column chromatography with PE / EtOAc (1 / 1) elution to give tert-butyl 3-[1-(5-bromopyridin-2-yl)pyrrolidine-3-yl]propionic acid (4.2 g, 28.0% yield) as a brown oil. (C 16 H 23 BrN2O2) [M+H] + The calculated LCMS (ESI) value is 355.1; the measured value is 355.0.

[0609] Step 6: At room temperature and under a nitrogen atmosphere, add Pd(PPh3)4 (0.98 g, 0.84 mmol, 0.1 equivalent) to a mixture of tert-butyl 3-[1-(5-bromopyridin-2-yl)pyrrolidine-3-yl]propionate (3 g, 8.44 mmol, 1 equivalent), 2,6-bis(benzyloxy)pyridin-3-ylboronic acid (4.25 g, 12.7 mmol, 1.5 equivalent), and K2CO3 (2.33 g, 16.89 mmol, 2 equivalent) in THF (30 mL) and H2O (10 mL). Stir the resulting mixture in a microwave at 110 °C for 40 minutes under a nitrogen atmosphere. Concentrate the resulting mixture under vacuum. The residue was purified by silica gel column chromatography with PE / EtOAc (1 / 1) elution to give tert-butyl 3-[1-[2,6-bis(benzyloxy)-[3,3-bipyridine]-6-yl]pyrrolidine-3-yl]propionate (7) (2.6 g, 53.34% yield) as a colorless oil. (C) 35 H 39 N3O4) [M+H + The calculated LCMS (ESI) value is 566.3; the measured value is 566.2.

[0610] Step 7: Add Pd / C (1.70 g) to a mixture of 3-[1-[2',6'-bis(benzyloxy)-[3,3'-bipyridine]-6-yl]pyrrolidine-3-yl]tert-butyl propionate (2.10 g, 3.71 mmol, 1 equivalent) in THF (6 mL) and EtOH (6 mL). Stir the resulting mixture at room temperature for 3 hours under a hydrogen atmosphere. Filter the resulting mixture. Concentrate the filtrate under vacuum. Purify the residue by silica gel column chromatography with CH2Cl2 / EtOAc (1 / 2) elution to give 3-[1-[5-(2,6-dioxopiridine-3-yl)pyridin-2-yl]pyrrolidine-3-yl]tert-butyl propionate (400 mg, 26.42% yield) as a colorless solid. (C 21 H 29 N3O4) [M+1 + MS (ESI) calculated value: 388.2; measured value: 388.3.

[0611] Step 8: 3-[1-[5-(2,6-dioxopiridine-3-yl)pyridin-2-yl]pyrrolidine-3-yl]propionate tert-butyl ester (490 mg, 1.27 mmol, 1 equivalent) was stirred in a mixture of HCl / dioxane (5 mL, 4 M) at room temperature for 2 hours. The resulting mixture was concentrated under vacuum. This yielded 3-[(3RS)-1-[5-[(3RS)-2,6-dioxopiridine-3-yl]pyridin-2-yl]pyrrolidine-3-yl]propionate (HA-11) as a white solid (HA-11) (379.1 mg, 81.56%). (C 17 H 21 N3O4) [M+H + The calculated LCMS (ESI) value is 332.2; the measured value is 332.1. 1 H NMR (300MHz, DMSO- d 6 ) δ 13.61 (s, 1H), 10.93 (s, 1H), 7.95 - 7.85 (m, 1H), 7.82 (d, J= 2.1Hz, 1H), 7.11 - 7.01 (m, 1H), 4.02 - 3.90 (m, 1H), 3.80 - 3.69 (m, 2H), 3.69 - 3.61 (m, 1H), 3.21 - 3.09(m, 1H), 2.77 - 2.48 (m, 1H), 2.47 - 2.37 (m, 1H), 2.36 - 2.19 (m, 3H), 2.17(s, 1H), 2 - 1.89 (m, 1H), 1.87 - 1.59 (m, 4H).

[0612] HA-12: Racemic-(R)-1-(5-((R)-2,6-dioxopiperidin-3-yl)pyridin-2-yl)pyrrolidine-3-carboxaldehyde

[0613]

[0614] Step 1: Add racemic-(3R)-3-(6-fluoropyridin-3-yl)piperidin-2,6-dione (1000.00 mg, 4.80 mmol), racemic-(3R)-pyrrolidine-3-ylmethanol (485.84 mg, 4.80 mmol), N,N-diisopropylethylamine (3.36 mL, 2.48 g, 19.21 mmol), and DMSO (7.00 mL) to a 40 mL vial. Stir the reaction mixture at 115 °C for 16 hours. The reaction mixture was then concentrated under reduced pressure and purified by reversed-phase column chromatography (415 g C18 silica, 0-10% MeCN / water + 0.1% TFA) to give (3RS&)-3-{6-[(3RS)-3-(hydroxymethyl)pyrrolidone-1-yl]pyridin-3-yl}piperidin-2,6-dione; trifluoroacetic acid (954 mg, 69%) as an amorphous solid. LCMS C 15 H 19 Theoretical value of N3O3: 289.1, measured value: m / z = 290.1 ​​[M+H] + .

[0615] Step 2: Add (3RS&)-3-{6-[(3RS)-3-(hydroxymethyl)pyrrolidone-1-yl]pyridin-3-yl}piperidin-2,6-dione; trifluoroacetic acid (954.00 mg, 2.37 mmol), sodium bicarbonate (0.99 g, 11.83 mmol), and DCM (50.00 mL) to 200 mL of RBF. Cool the reaction mixture to 0 °C, then add 1,1-bis(acetoxy)-3-oxo-1λ5,2-benzoiodopyrazine-1-yl acetate (1.10 g, 2.60 mmol) in a single batch. Stir and warm the reaction mixture to room temperature for 3 hours. Adsorb the crude reaction mixture onto silica and purify by FC (40 g silica, 50%-100% EtOAc / DCM + 1% TEA) to give the title compound (177 mg, 26%) as a white solid. LCMS C 15 H 17 Theoretical value of N3O3: 287.1, measured value: m / z = 288.0 [M+H] + .

[0616] HA-13: 1-(5-(2,6-dioxopiperidin-3-yl)pyridin-3-yl)piperidin-4-carboxaldehyde

[0617]

[0618] Step 1: At 20°C under N2, K3PO4 (89.6 g, 422 mmol, 1.00 equivalent), CuI (8.04 g, 42.2 mmol, 0.200 equivalent), and L-proline (5.54 g, 42.2 mmol, 0.200 equivalent) were added to a solution of piperidin-4-ylmethanol (24.3 g, 211 mmol, 1.00 equivalent) and 3,5-dibromopyridine (50.0 g, 211 mmol, 1.00 equivalent) in DMSO (400 mL). The mixture was stirred at 80°C under N2 for 12 hours. The mixture was cooled to 20°C and poured into water (1.00 L). The mixture was stirred at 20°C for 0.5 hours. The mixture was extracted with ethyl acetate (500 mL × 3). The organic layer was washed with brine (1.00 L), dried over Na2SO4, filtered, and concentrated. The residue was subjected to column chromatography (SiO2, petroleum ether / ethyl acetate = 5 / 1 to 0 / 1, R...) f Purification was performed using a concentration of 0.35 g / mL. The desired product was obtained as an orange solid (33.0 g, 119 mmol, 56.5% yield). LCMS: m / z = 270.8 (M+H). + .

[0619] Step 2: At 20°C under N2, Pd(dppf)Cl2 was added to a solution of (1-(5-bromopyridin-3-yl)piperidin-4-yl)methanol (20.0 g, 72.3 mmol, 1.00 equivalent) and 2,6-bis(benzyloxy)-3-(4,4,5,5-tetramethyl-1,3,2-dioxane-2-yl)pyridine (30.2 g, 72.3 mmol, 1.00 equivalent) in dioxane (250 mL) and H2O (50.0 mL). CH2Cl2 (5.91 g, 7.24 mmol, 0.100 equivalent) and K2CO3 (30.0 g, 217 mmol, 3.00 equivalent). The mixture was degassed and then stirred at 100 °C for 12 hours under N2. The reaction mixture was cooled to 20 °C and concentrated. The residue was poured into water (500 mL) and extracted with ethyl acetate (500 mL × 4). The combined organic layers were washed with brine (1000 mL), dried over Na2SO4, filtered, and concentrated. The residue was subjected to column chromatography (SiO2, petroleum ether / ethyl acetate = 5 / 1 to 1 / 3, R... f Purification was performed using a concentration of 0.30 g / mL. The desired product was obtained as a yellow solid (25.0 g, 51.3 mmol, 70.9% yield). LCMS: m / z = 482.1 (M+H). + .

[0620] Step 3: Under N2, add 10 wt% Pd / C (6.00 g, 49.2 mmol, 1.00 equivalent) and 20 wt% Pd(OH)2 (5.93 g, 8.45 mmol, 0.17 equivalent) to a solution of compound (1-(2',6'-bis(benzyloxy)-[3,3'-bipyridine]-5-yl)piperidin-4-yl) in THF (120 mL) and EtOH (120 mL). Degas the suspension under vacuum and purge several times with H2. Stir the mixture at 80 °C for 12 hours under H2 (50 psi). Cool the mixture to 20 °C and filter. Concentrate the filtrate. The residue was adjusted to pH 10 with saturated aqueous Na₂CO₃ solution, and the aqueous layer was extracted with ethyl acetate:THF (1:1, 1000 mL × 5). The combined organic layers were washed with brine (1000 mL), dried over Na₂SO₄, and concentrated under vacuum. The desired product (9.91 g, 24.1 mmol, 48.9% yield) was given as a pink solid without further purification. LCMS: m / z = 304.2 (M+H) + .

[0621] Step 4: At 20°C, DMP (20.4 g, 48.2 mmol, 14.93 mL, 2.00 equivalent) was added in portions to a solution of 3-(5-(4-(hydroxymethyl)piperidin-1-yl)pyridin-3-yl)piperidin-2,6-dione (9.91 g, 24.1 mmol, 1.00 equivalent) in DMSO (100 mL). The reaction mixture was stirred at 20°C for 1 hour. The mixture was poured into water (100 mL) and ethyl acetate (100 mL). The mixture was adjusted to pH 10 with a saturated aqueous solution of Na₂CO₃, and the aqueous layer was extracted with ethyl acetate (1000 mL × 5) and THF:MeOH (1:1, 1000 mL × 5). The combined organic layers were washed with Na₂S₂O₃ solution (1000 mL) and brine (1000 mL), dried over Na₂SO₄, and concentrated under vacuum. The crude product was ground with ethyl acetate (100 mL) at 20 °C for 30 minutes. HA-13 (4.92 g, 16.0 mmol, 66.5% yield) was given as a grayish-white solid. LCMS: m / z = 300.1 (MH) + . 1 H NMR: (400MHz, CDCl3) δ 9.72 (s, 1H), 8.34 - 8.21 (m, 2H), 7.99 (d, J =1.8Hz, 1H), 7.02 (t, J = 2.2Hz, 1H), 3.77 - 3.72 (m, 1H), 3.68 - 3.61 (m,2H), 3.00 - 2.92 (m, 2H), 2.84 - 2.76 (m, 1H), 2.75 - 2.65 (m, 1H), 2.50 -2.41 (m, 1H), 2.34 - 2.24 (m, 2H), 2.11 - 2.04 (m, 2H), 1.82 - 1.74 (m, 2H).

[0622] HA-14: Racemic-(R)-2-(1-(5-(2,6-dioxopiperidin-3-yl)pyridin-2-yl)piperidin-4-yl)acetaldehyde

[0623]

[0624] Step 1: Add racemic-(3R)-3-(6-fluoropyridin-3-yl)piperidine-2,6-dione (1500.00 mg, 7.20 mmol), 4-piperidineethanol (977.44 mg, 7.57 mmol), N,N-diisopropylethylamine (5.03 mL, 3.72 g, 28.82 mmol), and DMSO (10.00 mL) to a 40 mL vial. Stir at 130 °C for 16 hours. The reaction mixture was concentrated, and the resulting residue was purified by reversed-phase column chromatography (415 g C18 silica, 5%-50% MeCN / H2O + 0.1% TFA) to give racemic-(3R)-3-{6-[4-(2-hydroxyethyl)piperidin-1-yl]pyridin-3-yl}piperidin-2,6-dione as an amorphous solid; trifluoroacetic acid (2.10 g, 92% yield). LCMS C 17 H 23 Theoretical N3O3 value: 317.2, measured value: 318.2 [M+H] + .

[0625] Step 2: Add racemic-(3R)-3-{6-[4-(2-hydroxyethyl)piperidin-1-yl]pyridin-3-yl}piperidin-2,6-dione; trifluoroacetic acid (1600.00 mg, 3.71 mmol) and DCM (30.00 mL) to a 40 mL vial. Cool the reaction mixture to 0 °C, then add 1,1-bis(acetoxy)-3-oxo-1λ5,2-benzoiodopyrazine-1-ylacetate (1.73 g, 4.08 mmol) in a single addition. After 10 minutes, remove the ice bath and heat the reaction mixture to room temperature for 1 hour with stirring. Add 3 mL of TEA to the reaction mixture and adsorb the crude reaction mixture onto silica. Purify by column chromatography (80 g silica, 20%-100% EtOAc + 1% TEA / DCM) to give the title compound as a white solid (278 mg, 47% yield). LCMS C 17 H 21 Theoretical value of N3O3: 315.2, measured value: m / z = 316.2 [M+H] + .

[0626] HA-15: racemic-(R)-2-(4-(4-(2,6-dioxopiperidin-3-yl)pyridin-2-yl)piperazin-1-yl)acetic acid

[0627]

[0628] Step 1: Add racemic (3R)-3-(2-fluoropyridin-4-yl)piperidin-2,6-dione (1000.00 mg, 4.80 mmol), tert-butyl 2-(piperazin-1-yl)acetate (1443.01 mg, 7.20 mmol), DMSO (7.00 mL), and N,N-diisopropylethylamine (3.36 mL, 2.48 g, 19.21 mmol) to a 40 mL vial. Stir the reaction mixture at 120 °C for 3 days. Dilute the reaction mixture with brine and EtOAc. Extract the product with EtOAc (2×), and wash the combined organic layers with brine (4×), dry over MgSO4, and then concentrate. The residue was purified by column chromatography (80 g silica, 30%-100% EtOAc / DCM + 1% TEA) to give racemic 2-(4-{4-[(3R)-2,6-dioxopiridin-3-yl]pyridin-2-yl}piperazin-1-yl)tert-butyl acetate (1.454 g, 78% yield), as a grayish-white solid. LCMS C 20 H 28 Theoretical value of N4O4: 388.2, measured value: m / z = 389.2 [M+H] + .

[0629] Step 2: Racemic 2-(4-{4-[(3R)-2,6-dioxopiperidin-3-yl]pyridin-2-yl}piperazin-1-yl)tert-butyl acetate (1454.30 mg, 3.74 mmol), HFIP (5.00 mL), and trifluoroacetic acid (2.85 mL, 4.27 g, 37.44 mmol) were added to a 40 mL vial. The reaction mixture was stirred at room temperature for 16 hours. The reaction mixture was then concentrated. The resulting residue was purified by RP-FC (100 g C18 silica, 0–10% MeCN / H2O) to give the title compound as a white solid (813 mg, 65% yield). LCMS C 16 H 20 Theoretical value of N4O4: 332.1, measured value: m / z = 333.1 [M+H] + .

[0630] HA-16: Racemic-(R)-1-(4-(2,6-dioxopiperidin-3-yl)pyridin-2-yl)piperidin-4-carboxylic acid

[0631]

[0632] Step 1: Add racemic (3R)-3-(2-fluoropyridin-4-yl)piperidine-2,6-dione (1000 mg, 4.80 mmol), tert-butyl piperidine-4-carboxylate (978.87 mg, 5.28 mmol), N,N-diisopropylethylamine (3.36 mL, 2.48 g, 19.21 mmol), and DMSO (7.00 mL) to a 40 mL vial. Stir the reaction mixture at 120 °C for 16 hours. Dilute the reaction mixture with EtOAc and brine. Extract the product with EtOAc (2×). Wash the combined organic layers with brine (4×), dry over MgSO4, and then concentrate. The residue was purified by column chromatography (80 g silica, 0-70% EtOAc / DCM) to give racemic tert-butyl-1-{4-[(3R)-2,6-dioxopiperidin-3-yl]pyridin-2-yl}piperidine-4-carboxylate (1.235 g, 69% yield), a grayish-white solid. LCMS C 20 H 27 Theoretical value of N3O4: 373.2, measured value: m / z = 374.2 [M+H] + .

[0633] Step 2: Racemic tert-butyl piperidine-4-carboxylate (630.00 mg, 1.69 mmol) and HFIP (4.00 mL) were added to a 40 mL vial. Trifluoroacetic acid (1.28 mL, 1.92 g, 16.87 mmol) was added dropwise to the reaction mixture. After 2 hours, the reaction mixture was concentrated. The resulting residue was purified by reversed-phase column chromatography (100 g C18 silica, 0-15% MeCN / H2O) to give the title compound as a white solid (408 mg, 76% yield). LCMS C 16 H 19 Theoretical value of N3O4: 317.1, measured value: m / z = 318.1 [M+H] + .

[0634] HA-17: Racemic-(R)-1-(5-((R)-2,6-dioxopiperidin-3-yl)pyridin-2-yl)pyrrolidine-3-carboxylic acid

[0635]

[0636] Step 1: Add racemic (3R)-3-(6-fluoropyridin-3-yl)piperidin-2,6-dione (1000.00 mg, 4.80 mmol), racemic (3R)-pyrrolidine-3-carboxylic acid tert-butyl ester (822.51 mg, 4.80 mmol), N,N-diisopropylethylamine (3.36 mL, 2.48 g, 19.21 mmol), and DMSO (7.00 mL) to a 40 mL vial. Stir at 115 °C for 16 hours. Then dilute the reaction mixture with EtOAc and brine. The product was extracted with EtOAc (2×), the combined organic layers were washed with brine (4×), dried over MgSO4, and then purified by column chromatography (80 g silica, 10%-100% EtOAc / DCM) to give (3RS)-1-{5-[(3RS&)-2,6-dioxopiperidin-3-yl]pyridin-2-yl}pyrrolidine-3-carboxylic acid tert-butyl ester (779.1 mg, 45% yield) as a white solid. LCMS C 19 H 25 Theoretical value of N3O4: 359.2, measured value: m / z = 360.2 [M+H] + .

[0637] Step 2: Add (3RS)-1-{5-[(3RS&)-2,6-dioxopiperidin-3-yl]pyridin-2-yl}pyrrolidine-3-carboxylic acid tert-butyl ester (779.10 mg, 2.17 mmol), HFIP (4.00 mL), and trifluoroacetic acid (1.65 mL, 2.47 g, 21.68 mmol) to a 40 mL vial. Stir the reaction mixture for 4 hours, then concentrate. Purify the resulting residue by reversed-phase chromatography (100 g C18 silica, 0-10% MeCN / water) to give the title compound as a white solid (589 mg, 90% yield). LCMS C 15 H 17 Theoretical value of N3O4: 303.1, measured value: m / z = 304.0 [M+H] + .

[0638] HA-18: Racemic-(R)-3-(6-(piperidin-4-yloxy)pyridin-3-yl)piperidin-2,6-dione

[0639]

[0640] Step 1: Dissolve tert-butyl 4-hydroxypiperidin-1-carboxylate (1.14 g, 5.68 mmol) in NMP (10 mL) and cool the reaction mixture to 0 °C. Add sodium hydride (0.27 g, 11.36 mmol) and stir the reaction mixture for 5 min, then add 5-bromo-2-fluoropyridine (0.58 mL, 1.00 g, 5.68 mmol). Heat the reaction mixture to 60 °C for 4 h. Purify the product by direct injection using reversed-phase rapid column chromatography (0-100% acetonitrile / water) to give tert-butyl 4-[(5-bromopyridin-2-yl)oxy]piperidin-1-carboxylate (0.751 g, 37% yield). LCMS: C 15 H 21 The theoretical value for BrN₂O₃ is 357.25, and the measured value is: m / z = 358.10 [M+H] + .

[0641] Step 2: Add 0.750 g (2.10 mmol) of tert-butyl 4-[(5-bromopyridin-2-yl)oxy]piperidine-1-carboxylate and Pd(dppf)Cl2. DCM (0.342 g, 0.42 mmol), 1N cesium carbonate solution (5.25 mL, 1.71 g, 5.25 mmol), 2,6-bis(benzyloxy)pyridin-3-ylboronic acid (0.703 g, 2.10 mmol), and dioxane (5.00 mL) were combined in a sealed vial. The vial was purged with nitrogen and stirred at 100 °C for 60 min. The reaction mixture was poured onto brine and extracted with ethyl acetate, filtered, and concentrated on silica gel. The reaction mixture was purified by rapid column chromatography (0-100% ethyl acetate / hexane) to give tert-butyl 4-{[2',6'-bis(benzyloxy)-[3,3'-bipyridin]-6-yl]oxy}piperidine-1-carboxylate (1.05 g, 88% yield). LCMS: C 34 H 37 Theoretical value of N3O5: 567.69, measured value: m / z = 568.70 [M+H] + .

[0642] Step 3: 4-{[2',6'-bis(benzyloxy)-[3,3'-bipyridine]-6-yl]oxy}piperidine-1-carboxylic acid tert-butyl ester (1.05 g, 1.8 mmol) was dissolved in EtOH (20.00 mL). 10% carbon-supported palladium (0.20 g, 0.18 mmol) was added, and the reaction mixture was stirred under a hydrogen balloon for 12 hours. The reaction mixture was filtered through diatomaceous earth and concentrated to give 4-({5-[(3R)-2,6-dioxopiridine-3-yl]pyridine-2-yl}oxy)piperidine-1-carboxylic acid tert-butyl ester (0.647 g, 95%). LCMS: C 20 H27 Theoretical value of N3O5: 389.45, measured value: m / z = 390.20 [M+H] + .

[0643] Step 4: 4-({5-[(3R)-2,6-dioxadiazin-3-yl]pyridin-2-yl}oxy)piperidine-1-carboxylic acid tert-butyl ester (0.647 g, 1.66 mmol) was dissolved in DCM (10 mL). A dioxane solution of 4 M HCl (3 mL) was added, and the reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was concentrated on silica gel and purified by reversed-phase rapid column chromatography (0-100% acetonitrile / water) to give (3R)-3-[6-(piperidine-4-yloxy)pyridin-3-yl]piperidine-2,6-dione (0.427 g, 92% yield). LCMS: C 15 H 19 Theoretical value of N3O3: 289.34; Measured value: m / z = 290.20 [M+H] + .

[0644] HA-19: 1-[5-(2,4-dioxo-1,3-diazin-1-yl)pyridin-2-yl]piperidine-4-carboxaldehyde

[0645]

[0646] Step 1: A mixture of 2-fluoro-4-nitropyridine (20 g, 0.140 mol, 1 equivalent), piperidin-4-ylmethanol (24.318 g, 0.211 mol, 1.5 equivalent), and DIPEA (27.29 mL, 0.211 mol, 1.5 equivalent) in anhydrous DMSO (50 mL, 2.82 M) was stirred overnight at 90 °C. The reaction mixture was then poured into ice water. The resulting precipitate was filtered and purified by FC (DCM / MeOH-9 / 1) to give 33.37 g of [1-(5-nitropyridine-2-yl)piperidin-4-yl]methanol as a yellow solid (47% yield). LCMS: (M+H) + = 237.7 1 H NMR (300MHz, CDCl3) δ 9.05 (d, J = 2.8Hz, 1H), 8.20 (dd, J = 9.6, 2.8Hz, 1H), 6.60 (d, J = 9.6Hz, 1H), 4.59 (d, J =13.4Hz, 2H), 3.57 (d, J = 5.9Hz, 2H), 3.11 - 2.95 (m, 2H), 1.98 - 1.84 (m,3H), 1.31 (tdd, J = 14.3, 11.8, 4.2Hz, 2H).

[0647] Step 2: [1-(5-nitr...

Claims

1. A compound of formula (I): Formula (I) Or its pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers, wherein: R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; or optionally marked with 1-3 R a Substituted 4-12 membered heterocyclic groups; or optionally replaced by 1-3 R groups. a Substituted 5-12 heteroaryl groups; L is -L1-L2-L3-L4-, and each L1, L2, L3, and L4 is independently: a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl; b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl; c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups; d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups; e) Direct key; f) Randomly selected by 1-3 R d Replacement C 1-12 Alkylene chain; g) Randomly selected by 1-3 R d Replacement C 2-12 Alkenyl chain; h) can be arbitrarily assigned to 1 to 3 R d Replacement C 2-12 Alkyne chain; i) 1-6 ethylene glycol units; j) 1-6 propylene glycol units; or k)-C(O)-, -C(O)O-, -O-, -N(R c )-, -S-, -C(S)-, -C(S)-O-, -S(O)2-, -S(O)=N-, -S(O)2NH-, -C(O)-N(R c )-, -C=N-, -O-C(O)-N(R c )- or -O-C(O)-O-; Each R a Independently a halogenated group, -CN, optionally enclosed by 1 to 3 R groups d Replacement C 1-3 Alkyl groups, optionally with 1 to 3 R groups d Replacement C 3-6 cycloalkyl, or -OR c ; Each R b Independently, it can be an oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR c -C(O)-R c -C(O)OR c -C(O)-N(R) c (R) c ), -N(R c (R) c ), -N(R c )C(O)-R c -N(R) c )C(O)OR c -N(R) c )C(O)N(R c (R) c ), -N(R c )S(O)2(R c -NR c S(O)2N(R c (R) c ), -N(R c )S(O)2O(R c -OC(O)R c -OC(O)-N(R) c (R) c ), -Si(R c )3、-SR c -S(O)R c -S(O)(NH)R c -S(O)2R c or -S(O)2N(R c (R) c ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. d replace; Each R c Independently hydrogen or C 1-6 alkyl; Each R d Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl; W is -C(R) g - or -N-; Ring B is C 6-12 aryl, 5-12-membered heteroaryl, or 4-12-membered heterocyclic, each optionally bound by 1 to 3 R groups. j replace; Each R j Independently, it can be hydrogen, oxo group, imino group, sulfonoxime group, halo group, nitro group, -CN, or C. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 aryl, 5-12 heteroaryl, 4-12 heterocyclic, -OR g -C(O)-R g -C(O)OR g -C(O)-N(R) g (R) g ), -N(R g (R) g ), -N(R g )C(O)-R g -N(R) g )C(O)OR g -N(R) g )C(O)N(R g (R) g ), -N(R g )S(O)2(R g -NR g S(O)2N(R g (R) g ), -N(R g )S(O)2O(R g -OC(O)R g -OC(O)-N(R) g (R) g ), -Si(R g )3、-SR g -S(O)R g -S(O)(NH)R g -S(O)2R g or -S(O)2N(R g (R) g ), where C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-15 cycloalkyl, C 1-8 Haloalkyl, C 6-12 Each of the aryl, 5-12-membered heteroaryl, and 4-12-membered heterocyclic groups can be optionally divided by 1 to 3 R groups. k replace; R g Is it hydrogen or C? 1-6 Alkyl; and Each R k Independently, a halogenated group, an oxo-group, -CN, -OH, or a C group optionally substituted with 1 to 3 fluorine groups. 1-6 Alkyl, or C 3-8 Cycloalkyl, or -OC substituted with 1 to 3 fluorine atoms. 1-6 alkyl.

2. The compound of claim 1, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein: R 1 It is optional to be 1-3 R a Replacement C 1-10 Alkyl; optionally marked with 1-3 R a Replacement C 3-10 cycloalkyl; or optionally marked with 1-3 R a Substituted 4-12 membered heterocyclic groups.

3. The compound of claim 1 or claim 2, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein, The B ring has one of the following structures: , , , , or ; Each L1, L2, L3, and L4 is independently: a) Randomly selected by 1-3 R b Replacement C 3-12 cycloalkyl; b) Randomly selected by 1-3 R b Replacement C 6-12 Aryl; c) Randomly selected by 1-3 R b Substituted 4-12 membered heterocyclic groups; d) Optionally placed by 1-3 R b Substituted 5-12 heteroaryl groups; e) Direct key; f) Optionally divided by 1-3 R d Replacement C 1-12 alkylene chains; or g)-C(O)-、-O-、-N(R c - or -C(O)-N(R) c )-.

4. The compound of any one of claims 1-3, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein W is -CH-.

5. The compound of any one of claims 1-3, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein W is -N-.

6. The compound of any one of claims 2 to 5, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein L1 is , , , , , , or ,and -L2-L3-L4- is one of the following structures: -C(O)-, -(CH2) m -、 , , , , , , , , , , , , , , , , , , or Where m is 1, 2, or 3, and R c Is it H or C? 1-3 alkyl.

7. The compound of any one of claims 1 to 5, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof. Where L1 is , , , , , , or ,and -L2-L3-L4- is one of the following structures: , , , , , , , , , or .

8. The compound of any one of claims 1 to 5, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof. Where L1 is or And -L2-L3-L4- is one of the following structures: -C(O)-, -(CH2) m -、 , , , , , , , , , , , , , , , , , , or Where m is 1, 2, or 3, and R c Is it H or C? 1-3 alkyl.

9. The compound of any one of claims 2 to 5, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein L has one of the following structures: , , , , , , , , , , , , , , , , , , , , , , , , , or .

10. The compound of any one of claims 1 to 5, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein L has one of the following structures: , , , , , , , , , , , , , , , , , , , , , , or .

11. The compound of any one of the preceding claims, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein R 1 yes: a) Optionally selected by one to three independent free radicals, -OH, -OC 1-4 The C-substituents of the group consisting of alkyl and -CN 1-5 alkyl; b) Optionally selected by one to three independent free halogen groups, C 1-5 Alkyl, -OH, -OC 1-4 Substituents of alkyl groups and -CN groups are 4-8 membered heterocyclic groups that are substituted. c) Optionally selected by one to three independent free halogen groups, C 1-5 Alkyl, -OH, -OC 1-4 The C-substituents of the group consisting of alkyl and -CN 3-10 cycloalkyl; d) Optionally selected by one to three independent free halogenated groups, C 1-5 Alkyl, -OH, -OC 1-4 5-6 membered heteroaryl groups consisting of alkyl groups and -CN groups.

12. The compound of any one of the preceding claims, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein R 1 It is a C that is optionally substituted with a halogenated group, -OH or -CN. 1-5 alkyl.

13. The compound of claim 12, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein R 1 It is an oxocyclic butyl group, tetrahydrofuranyl group, tetrahydro-2- H -pyranyl, cyclobutyl, cyclohexyl, cyclopropyl, isoxazolyl or C 1-4 Alkyl groups, each optionally selected independently from one to three F and C atoms. 1-3 Substituents in the group consisting of alkyl, -OH, -OCH3 or -CN.

14. The compound of claim 11, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein R 1 It is tetrahydrofuranyl, cyclohexyl or C 1-3 Alkyl groups, each optionally composed of one to three free radicals selected from F, C 1-3 Substituents in the group consisting of alkyl, -OH, -OCH3 or -CN.

15. The compound of any one of claims 11 to 14, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein... Some have one of the following structures: , , , , , , , , , , , , , , or .

16. The compound of any one of claims 1 to 15, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein... Some have structure 。 17. The compound of any one of claims 1-6 and 11-16, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein L is .

18. The compound of any one of claims 1-17, or a pharmaceutically acceptable salt, isotopic form, isolated stereoisomer, or mixture of stereoisomers thereof, wherein the B ring is .

19. A compound, or a pharmaceutically acceptable salt thereof, said compound having the following structure: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 or 。 20. A pharmaceutical composition comprising the compound of any one of claims 1 to 19, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

21. Use of the compound of any one of claims 1 to 19, or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 20, in the preparation of a medicament for treating cancer.

22. The use of claim 21, wherein the cancer is lymphoma, leukemia, or myelodysplastic syndrome (MDS).

23. The use according to claim 22, wherein the leukemia is acute myeloid leukemia (AML).

24. Use of the compound of any one of claims 1 to 19, or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 20, in the preparation of a medicament for treating metabolic disorders.

25. The use according to claim 24, wherein the metabolic disorder is selected from diabetes, dyslipidemia, obesity, glucose intolerance, and hypertension.

26. The use of claim 25, wherein the diabetes is type I diabetes or type II diabetes.

27. The use of claim 25, wherein the dyslipidemia includes elevated serum cholesterol.

28. The use of claim 25, wherein the dyslipidemia includes elevated triglycerides.

29. Use of the compound of any one of claims 1 to 19, or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 20, in the preparation of a medicament for treating inflammatory conditions.

30. The use of claim 25, wherein the inflammatory condition is selected from inflammatory bowel disease (IBD), necrotizing enterocolitis, Lyme disease, arthritis, psoriasis, pelvic inflammatory disease, systemic lupus erythematosus (SLE), Sjögren's syndrome, inflammation associated with gastrointestinal infection, viral myocarditis, acute tissue injury, chronic tissue injury, non-alcoholic steatohepatitis (NASH), alcoholic hepatitis, and nephropathy.

31. The use of claim 30, wherein the arthritis is rheumatoid arthritis (RA) or gout.

32. The use of claim 30, wherein the inflammatory bowel disease is Crohn's disease or ulcerative colitis.

33. The use of claim 30, wherein the gastrointestinal infection-related inflammation is an inflammation related to Clostridium difficile infection.

34. The use according to claim 30, wherein the kidney disease is chronic kidney disease or diabetic nephropathy.

35. Use of the compound of any one of claims 1 to 19, or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 20, in the preparation of a medicament for the treatment of metabolic syndrome.

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