Imidazo[1,2-a]pyridine type IRAK degradation agent and use thereof

Abstract

Provided in the present application are an imidazo[1,2-a]pyridine type IRAK4 degradation agent and the use thereof. Said IRAK4 degradation agent has a structure shown as formula I. Said IRAK4 degradation agent has remarkable degradation activity on IRAK4 in cells, and thus can be used for preparing drugs for treating and / or preventing IRAK4-mediated related diseases or disorders.

Description

An imidazo[1,2-a]pyridine IRAK degradation agent and its application Technical Field

[0001] The present application belongs to the technical field of drug synthesis and relates to an imidazo[1,2-a]pyridine IRAK4 degrader and its application. Background Art

[0002] Interleukin-1 receptor kinase 4 (IRAK4) is an isoenzyme of the intracellular serine-threonine kinase IRAK protein family. It is a key node in the downstream signaling pathways of Toll-like receptors (TLRs) and interleukin-1 receptor (IL-1R), playing a vital role in the immune system. Its overactivation, or abnormal activation due to mutations, is involved in the occurrence and progression of inflammatory diseases and tumors.

[0003] TLRs and IL-1Rs share a conserved TLR / IL-1R (TIR) ​​domain to recruit the adaptor protein MyD88 within the cell. MyD88 then recruits IRAK4 to form the Myddosome. Within the Myddosome, IRAK4 is activated through trans-autophosphorylation, which in turn activates a series of downstream transcription factors, such as NF-κB, CREB, AP-1, and IRF, promoting the secretion of pro-inflammatory cytokines and the proliferation and differentiation of immune cells. Therefore, IRAK4 plays a crucial role in the onset and progression of inflammatory diseases.

[0004] Dysregulation of the TLR / IL-1R signaling pathway is also closely related to the occurrence and progression of cancer. Mutations in proteins in the TLR / IL-1R pathway can lead to overactive signals and increased NF-κB activity, promoting cancer.

[0005] IRAK4 mediates IL-1R / TLR downstream signaling pathways and participates in immune surveillance through two pathways: First, IRAK4 possesses kinase activity, phosphorylating downstream proteins IRF5 / 7; second, IRAK4 acts as a scaffold, responsible for forming the protein multimer complex, the myddosome. Although numerous IRAK4 small molecule kinase inhibitors are currently available, they only inhibit the activity of the kinase itself, exhibiting moderate efficacy and failing to disrupt complex formation to completely block the generation of inflammatory response signals.

[0006] Targeted protein degradation (TPD) is an emerging therapeutic approach that has attracted considerable attention due to its therapeutic potential to regulate proteins that are difficult to target with traditional small molecules. Protein degradation targeting chimeras (PROTACs) utilize the ubiquitin protease system (UPS), a natural protein degradation system within the cell, to achieve targeted degradation of the protein of interest (POI). PROTACs are heterobifunctional small molecules, one end of which targets the POI and the other end recruits an E3 ubiquitin ligase to form a ternary complex. The POI is then labeled with ubiquitin for recognition and degradation by the proteasome.

[0007] Compared with traditional small molecule drugs, PROTAC molecules have the following advantages: (1) They have catalytic degradation function. Unlike each small molecule inhibitor that can only act on one protein molecule, each PROTAC molecule can degrade many protein molecules, so a very low dose can have a good drug effect; (2) They work by degrading the target protein, so they can overcome the problem of small molecule drug resistance caused by increased target protein expression, and can also block the non-enzymatic function of the target. Therefore, in view of the characteristics of IRAK4 having both kinase activity and scaffold function, the use of PROTAC technology can degrade IRAK4 protein, block kinase activity and destroy the target protein scaffold function at the same time, and achieve complete inhibition of the pathway compared to conventional kinase inhibitors, resulting in better inhibition of inflammatory response or anti-tumor activity. Therefore, in this field, the further development of such molecules is of great significance.

[0008] Summary of the Invention

[0009] The present application provides an imidazo[1,2-a]pyridine IRAK4 degrader and its application.

[0010] In a first aspect, the present application provides an imidazo[1,2-a]pyridine-based IRAK4 degrader, wherein the imidazo[1,2-a]pyridine-based IRAK4 degrader has a structure as shown in the following formula I:

[0011] wherein Ring A is a 6-10 membered aryl group or a 5-10 membered heteroaryl group;

[0012] Ring B is a substituted or unsubstituted 4-10 membered cycloalkyl group or a substituted or unsubstituted 4-10 membered heterocycloalkyl group;

[0013] Ring C is a substituted or unsubstituted 4-10 membered cycloalkyl group or a substituted or unsubstituted 4-10 membered heterocycloalkyl group;

[0014] X is CH2 or C=O;

[0015] R aEach is independently selected from halogen, cyano, substituted or unsubstituted C1-C4 alkyl, substituted or unsubstituted C1-C4 alkoxy, di(C1-C4 alkyl)amino, 5-10 membered cycloalkyl, 5-10 membered heterocycloalkyl;

[0016] m is an integer from 0 to 5;

[0017] R b Selected from C1-C4 alkoxy, C3-C6 cycloalkyloxy or hydroxydi(C1-C4 alkyl)methyl;

[0018] Rc is hydrogen, C1-C4 alkyl, C1-C4 alkoxy or halogen; and

[0019] L is (CH2) n 、(CH2) n CO, 4-8 membered cycloalkyl or 4-8 membered heterocycloalkyl, wherein n is an integer of 0-5 (e.g., 0, 1, 2, 3, 4 or 5).

[0020] In the present application, the substituents in the substituted groups as described above are selected from halogen, oxo, cyano, amino, hydroxyl, C1-C6 alkyl or -O-(C1-C6 alkyl).

[0021] Preferably, the ring A is The wavy line represents the attachment site of the group.

[0022] Preferably, the ring B is The wavy line represents the attachment site of the group.

[0023] Preferably, the ring C is The wavy line represents the attachment site of the group.

[0024] Preferably, R a Each independently selected from fluorine, chlorine, cyano, trifluoromethyl, trifluoromethoxy, The wavy line represents the attachment site of the group.

[0025] Preferably, R b Selected from methoxy, ethoxy, isopropoxy, cyclopropyloxy or In any of the above, the wavy line represents the attachment site of the group.

[0026] Preferably, R c is selected from hydrogen, fluorine, chlorine or bromine.

[0027] Preferably, L is -CH2-, -CH2CH2-, -CH2CH2CH2-, -COCH2-, -COCH2CH2-, -COCH2CH2CH2- or

[0028] Preferably, the imidazo[1,2-a]pyridine IRAK4 degrader is selected from any one of the following compounds:

[0029] In a second aspect, the present application provides a pharmaceutically acceptable salt of the imidazo[1,2-a]pyridine IRAK4 degrader as described in the first aspect.

[0030] Preferably, the pharmaceutically acceptable salt includes any one of the following salts: sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, hydrochloride, hydrobromide, hydroiodide, acetate, propionate, decanoate, octanoate, acrylate, formate, isobutyrate, hexanoate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate , maleate, butyne-1,4-dioate, hexyne-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, sulfonate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, gamma-hydroxybutyrate, glycolate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, or mandelate.

[0031] In a third aspect, the present application provides stereoisomers, geometric isomers or tautomers of the imidazo[1,2-a]pyridine IRAK4 degrader as described in the first aspect.

[0032] In a fourth aspect, the present application provides a pharmaceutical composition comprising the above-described imidazo[1,2-a]pyridine IRAK4 degrader, its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts.

[0033] In a fifth aspect, the present application provides the use of the above-mentioned imidazo[1,2-a]pyridine IRAK4 degrader, its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts or the pharmaceutical composition in the preparation of drugs for treating diseases or conditions mediated by IRAK4.

[0034] Preferably, the disease comprises an inflammatory disease, an autoimmune disease or a tumor.

[0035] Preferably, the inflammatory disease is selected from Crohn's disease, ulcerative colitis, asthma, graft-versus-host disease, chronic obstructive pulmonary disease, atopic dermatitis, gout, gouty arthritis, conjunctivitis, hepatitis, chronic inflammatory lung disease, thyroiditis or interstitial cystitis.

[0036] Preferably, the autoimmune disease is selected from Graves' disease, rheumatoid arthritis, systemic lupus erythematosus, lupus nephritis, cutaneous lupus, psoriasis, psoriatic arthritis, cryptopyrin-associated periodic syndrome, TNF receptor-associated periodic syndrome, multiple sclerosis, allergic rhinitis, scleroderma, dermatomyositis, vasculitis or nephritis.

[0037] Preferably, the tumor is selected from lung cancer, breast cancer, prostate cancer, pancreatic cancer, kidney cancer, liver cancer, gastrointestinal cancer, cervical cancer, endometrial cancer, testicular cancer, genitourinary tract cancer, colorectal cancer, laryngeal cancer, skin cancer, bone cancer, head and neck tumor, sarcoma, brain tumor, glioblastoma, melanoma, multiple myeloma, lymphoma or leukemia.

[0038] Compared with the prior art, this application has the following beneficial effects:

[0039] The compounds of the present application have significant degradation ability for IRAK4 in THP1 cells, and the half degradation concentration (DC 50 ) can reach the nanomolar level; the results of Western blotting experiments also showed that the compound of the present application has a strong degradation activity on IRAK4 protein in OCI-LY10 cells at concentrations of 100nM and 1000nM.

[0040] In in vitro and in vivo metabolic stability studies, the compounds of the present application have high metabolic stability in liver microsomes of different species, and in in vivo pharmacokinetic studies in mice, they have good pharmacokinetic properties such as low clearance rate, high plasma exposure, and high oral bioavailability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figures 1 to 26 are respectively the results of protein immunoblotting of the degradation of IRAK4 protein in OCI-LY10 cells by the compounds of Examples 1 to 26 at concentrations of 100 nM and 1000 nM; in the figures, "rabbit anti-IRAK4" indicates that rabbit anti-IRAK4 antibody was used as the primary antibody to detect IRAK4 protein, and "mouse anti-GAPDH" indicates that mouse anti-GAPDH antibody was used as the primary antibody to detect GAPDH. DETAILED DESCRIPTION

[0042] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0043] In the following examples, unless otherwise noted by structural formula or chemical name, molecules with a single chiral center exist as racemic mixtures. Unless otherwise noted by structural formula or chemical name, molecules with two or more chiral centers exist as racemic mixtures of diastereomers. Single enantiomers / diastereomers can be obtained by methods known to those skilled in the art.

[0044] Preparation method

[0045] The compounds described herein can be synthesized according to the synthetic schemes herein and / or techniques well known in the art. For example, the compounds provided herein can be prepared according to the following general synthetic methods.

[0046] General Synthesis Method 1

[0047] Specifically, in general synthetic method 1, intermediate Int-a undergoes a substitution reaction with HOOC-L1-Y under alkaline conditions to obtain intermediate Int-b; alternatively, intermediate Int-a undergoes a substitution reaction with t-BuOOC-L1-Y under alkaline conditions, and the resulting product is then de-tert-butylated with trifluoroacetic acid or hydrochloric acid to obtain intermediate Int-b; intermediate Int-b is then condensed with intermediate Int-c in the presence of a condensing agent and a base to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate. Y is a halogen, preferably bromine and iodine. Ra, Rb, Rc, m, ring A, ring B, ring C, L, and X are as defined above.

[0048] General synthetic method 2:

[0049] Specifically, in general synthetic method 2, intermediate Int-a undergoes a substitution reaction with (RdO)2CH-L1-Y under alkaline conditions to obtain intermediate Int-d; intermediate Int-d reacts with trifluoroacetic acid or hydrochloric acid to obtain intermediate Int-e; intermediate Int-e then undergoes a reductive amination reaction with intermediate Int-c to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate. Y is a halogen, preferably bromine and iodine. The reducing agent for the reductive amination reaction includes but is not limited to Pd / C, sodium borohydride, sodium cyanoborohydride, borane, and sodium triacetoxyborohydride. Rd is methyl or ethyl. Ra, Rb, Rc, m, ring A, ring B, ring C, L, and X are as defined above.

[0050] General synthetic method 3:

[0051] Specifically, in general synthetic method 3, intermediate Int-c undergoes a substitution reaction with (RdO)2CH-L1-Y under alkaline conditions to obtain intermediate Int-f; intermediate Int-f reacts with trifluoroacetic acid or hydrochloric acid to obtain intermediate Int-g; intermediate Int-g then undergoes a reductive amination reaction with intermediate Int-a to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate. Y is a halogen, preferably bromine and iodine. The reducing agent for the reductive amination reaction includes but is not limited to Pd / C, sodium borohydride, sodium cyanoborohydride, borane, and sodium triacetoxyborohydride. Rd is methyl or ethyl. Ra, Rb, Rc, m, ring A, ring B, ring C, L, and X are as defined above.

[0052] General synthetic method 4:

[0053] Specifically, in general synthetic method 4, intermediates Int-h and Int-i undergo a substitution reaction under alkaline conditions to obtain intermediate Int-f; intermediate Int-f reacts with trifluoroacetic acid or hydrochloric acid to obtain intermediate Int-g; intermediate Int-g then undergoes a reductive amination reaction with intermediate Int-a to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, or sodium bicarbonate. The reducing agent for the reductive amination reaction includes but is not limited to Pd / C, sodium borohydride, sodium cyanoborohydride, borane, or sodium triacetoxyborohydride. Rd is methyl or ethyl. Ra, Rb, Rc, m, Ring A, Ring B, Ring C, L, and X are as defined above.

[0054] General synthetic method 5:

[0055] Specifically, in general synthetic method 5, intermediates Int-h and Int-j undergo a substitution reaction under alkaline conditions to obtain intermediate Int-k; intermediate Int-k reacts with an oxidizing agent to obtain intermediate Int-g; intermediate Int-g then undergoes a reductive amination reaction with intermediate Int-a to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate. The reducing agent for the reductive amination reaction includes but is not limited to Pd / C, sodium borohydride, sodium cyanoborohydride, borane, and sodium triacetoxyborohydride. Ra, Rb, Rc, m, Ring A, Ring B, Ring C, L, and X are as defined above.

[0056] General synthetic method 6:

[0057] Specifically, in general synthetic method 6, intermediate Int-k reacts with methanesulfonyl chloride under alkaline conditions to obtain intermediate Int-1; intermediate Int-1 then undergoes a substitution reaction with intermediate Int-a under alkaline conditions to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate. Ra, Rb, Rc, m, Ring A, Ring B, Ring C, L, and X are as defined above.

[0058] General synthetic method 7:

[0059] Specifically, in general synthetic method 7, intermediate Int-a undergoes a reductive amination reaction with intermediate Int-m, or intermediate Int-a undergoes a substitution reaction with intermediate Int-n under alkaline conditions to obtain intermediate Int-o; intermediate Int-o reacts with trifluoroacetic acid or hydrochloric acid to obtain intermediate Int-p; intermediate Int-p then undergoes a reductive amination reaction with intermediate Int-q to obtain a compound of formula I. The base is an inorganic base or an organic base, including but not limited to triethylamine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate. The reducing agent for the reductive amination reaction includes but is not limited to Pd / C, sodium borohydride, sodium cyanoborohydride, borane, and sodium triacetoxyborohydride. Ra, Rb, Rc, m, Ring A, Ring B, Ring C, L, and X are as defined above.

[0060] Preparation Example

[0061] The compounds described herein can be synthesized according to one or more synthesis schemes and / or technology well known in the art herein. It will be appreciated by those skilled in the art that the synthetic methods of certain embodiments described in detail herein can be easily adapted to synthesize other embodiments. In some embodiments, the compounds described herein can be prepared by an appropriate combination of synthetic methods well known in the art. Many starting materials and other reagents can be purchased from commercial suppliers, such as Alfa Aesar (China) Chemical Co., Ltd., or easily prepared using synthetic methods commonly used in this area.

[0062] 1 H NMR spectra were recorded on an instrument operating at 400 MHz. H NMR spectra were obtained as solutions (reported in ppm). When peak multiplicities are reported, the following abbreviations are used: s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet), br (broad), dd (doublet of doublets), dt (doublet of triplets). Coupling constants are given in Hertz (Hz).

[0063] If desired, the (R)- and (S)-isomers of the non-limiting exemplary compounds, if present, can be resolved by methods known to those skilled in the art, such as by forming diastereomeric salts or complexes, which can be separated by, for example, crystallization; by forming diastereomeric derivatives, which can be separated by, for example, crystallization or chromatography; by selectively reacting one enantiomer with an enantiomer-specific reagent, followed by separation of the modified and unmodified enantiomers; or by chromatographic separation in a chiral environment, such as a chiral chromatographic column. Alternatively, a specific enantiomer can be prepared by asymmetric synthesis using optically active reagents, substrates, catalysts, or solvents, or by converting one enantiomer into the other by asymmetric transformation.

[0064] Preparation of compounds:

[0065] Intermediate 1: N-(7-(2-hydroxypropan-2-yl)-2-(piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide hydrochloride (IM-1)

[0066] Step 1: Preparation of methyl 6-bromo-2-(1-(tert-butoxycarbonyl)piperidin-4-yl)imidazo[1,2-a]pyridine-7-carboxylate (IM-1a)

[0067] 4-(2-bromoacetyl)piperidine-1-carboxylic acid tert-butyl ester (25.0g, 81.6mmol) and 2-amino-5-bromoisonicotinate (18.8g, 81.6mmol) were dissolved in acetonitrile (150mL) and toluene (100mL). Sodium bicarbonate (13.6g, 163mmol) was added to the mixture at 25°C, and the reaction mixture was heated to 90°C and stirred at 90°C for 12 hours. Thin layer chromatography showed that the reaction was complete. The reaction mixture was poured into ice water (500mL) and stirred for 10 minutes. The aqueous phase was extracted with ethyl acetate (300mL×3). The combined organic phase was washed with brine (500mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio=100 / 1~0 / 1) to obtain compound IM-1a as a dark brown solid (20.0g).

[0068] Step 2: Preparation of methyl 2-(1-(tert-butoxycarbonyl)piperidin-4-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridine-7-carboxylate (IM-1b)

[0069] Compound IM-1a (20.0 g, 45.6 mmol) and 6-(trifluoromethyl)pyridine-2-carboxamide (26.0 g, 136 mmol) were dissolved in dioxane (200.0 mL). Cesium carbonate (29.7 g, 90.7 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (10.5 g, 18.2 mmol), and palladium acetate (2.04 g, 9.13 mmol) were added to the reaction mixture under nitrogen at 25°C. The reaction mixture was heated to 100°C and stirred at 100°C for 12 hours. The reaction mixture was cooled to 25°C and concentrated under reduced pressure. The residue was poured into ice water (300 mL) and stirred for 5 minutes. The aqueous phase was extracted with ethyl acetate (300 mL x 3), and the combined organic phases were washed with brine (500 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain compound IM-1b as a yellow solid (10.0 g).

[0070] Step 3: Preparation of tert-butyl 4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidine-1-carboxylate (IM-1c)

[0071] Compound IM-1b (10.0 g, 18.1 mmol) was dissolved in tetrahydrofuran (100 mL). The reaction mixture was cooled to 0°C and methylmagnesium bromide (3 M, 36.5 mL) was slowly added dropwise. After the addition was complete, the system was slowly warmed to 25°C and stirred at 25°C for 3 hours. The reaction was quenched with aqueous ammonium chloride (200 mL) and extracted with ethyl acetate (3 × 100 mL). The combined organic layers were dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain compound IM-1c as a white solid (4.00 g, crude product).

[0072] Step 4: Preparation of N-(7-(2-hydroxypropan-2-yl)-2-(piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide hydrochloride (IM-1)

[0073] Dissolve compound IM-1c (4.00 g, 7.32 mmol) in dioxane (40.0 mL). Cool the mixture to 0°C and slowly add hydrochloric acid-dioxane (4.00 M, 2.00 equiv). After the addition is complete, slowly warm the mixture to 25°C and stir at 25°C for 3 hours. Concentrate the reaction mixture in vacuo to obtain compound IM-1 as a white solid (3.00 g, crude, hydrochloride salt).

[0074] Intermediate 2: N-(7-methoxy-2-(piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0075] Step 1: Preparation of tert-butyl 4-(6-bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)piperidine-1-carboxylate (IM-2a)

[0076] Tert-butyl 4-(2-bromoacetyl)piperidine-1-carboxylate (6.00 g, 19.6 mmol) was dissolved in toluene (13.9 mL) and acetonitrile (27.9 mL). Sodium bicarbonate (3.29 g, 39.2 mmol) and 5-bromo-4-methoxy-2-aminopyridine (3.98 g, 19.6 mmol) were added at room temperature. The reaction mixture was then heated to 90°C and stirred for 12 hours. Water (50 mL) was added to the reaction mixture, which was then extracted with ethyl acetate (50 mL x 3). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to afford intermediate IM-2a as a yellow solid (4.00 g).

[0077] Step 2: Preparation of tert-butyl 4-(7-methoxy-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidine-1-carboxylate (IM-2b)

[0078] Compound IM-2a (4.40 g, 10.7 mmol) and 6-(trifluoromethyl)pyridine-2-carboxamide (4.08 g, 21.4 mmol) were dissolved in 1,4-dioxane (40.0 mL). 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene (2.48 g, 4.29 mmol), cesium carbonate (6.99 g, 21.4 mmol), and palladium acetate (481 mg, 2.14 mmol) were added sequentially at room temperature under nitrogen. The reaction mixture was then heated to 100°C and stirred for 12 hours. The reaction mixture was cooled to room temperature, diluted with water (40.0 mL), and extracted with ethyl acetate (50.0 mL x 3). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to give IM-2b as a yellow solid (3.00 g).

[0079] 1 HNMR: (400MHz, DMSO-d6) δ10.19(s, 1H), 9.34(s, 1H), 8.36-8.48(m, 2H), 8.12-8.27(m, 1H), 7.66(s, 1H), 7.08(s, 1H), 3.98(s, 5H), 2.71-2.97(m, 3H), 1.90-2.01(m, 2H), 1.56-1.46(m, 2H), 1.41(s, 9H).

[0080] Step 3: Preparation of N-(7-methoxy-2-(piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-2)

[0081] Compound IM-2b (500 mg, 1.06 mmol) was dissolved in 1,4-dioxane (5.00 mL), hydrochloric acid / 1,4-dioxane (4 M, 12.0 mL) was added, and the reaction mixture was stirred at 25° C. for 3 hours. The reaction mixture was concentrated to dryness under reduced pressure to obtain intermediate IM-2 as a yellow solid (400 mg, crude product).

[0082] Intermediate 3: 2-(4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)acetic acid (IM-3)

[0083] Compound IM-1 (500 mg, 1.03 mmol) and 2-bromoacetic acid (215 mg, 1.55 mmol) were dissolved in N,N-dimethylformamide (5.00 mL). Triethylamine (313 mg, 3.10 mmol) was added to the reaction mixture at 25°C. The reaction mixture was stirred at 25°C for 2 hours. The reaction mixture was concentrated under reduced pressure to give compound IM-3 as a yellow solid (550 mg, crude product), which was used directly without further purification.

[0084] Intermediate 4: 3-(4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)propanoic acid (IM-4)

[0085] Intermediate IM-1 (150 mg, 309 μmol) and 3-bromopropionic acid (71.1 mg, 464 μmol) were dissolved in dichloromethane (2.00 mL). Triethylamine (94.1 mg, 929 μmol) was added to the reaction mixture at 25°C. The reaction was stirred at 25°C for 12 hours. The reaction mixture was concentrated under reduced pressure to give compound IM-4 as a yellow solid (210 mg, crude product), which was used directly without further purification.

[0086] Intermediate 5: 4-(4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)butanoic acid (IM-5)

[0087] Step 1: Preparation of tert-butyl 4-(4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)butanoate (IM-5a)

[0088] Compound 1 (300 mg, 670 μmol) was dissolved in acetone (3.00 mL). 4-Bromobutyric acid tert-butyl ester (299 mg, 1.34 mmol) and potassium carbonate (277 mg, 2.01 mmol) were added at 25°C. The mixture was heated to 60°C and stirred for 12 hours. The reaction mixture was concentrated to dryness under reduced pressure. The residue was purified by preparative HPLC (column: Waters Xbridge BEH C18 100*30 mm*10 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 35%-65%, 8 min) to afford the crude intermediate IM-5a as an off-white solid (150 mg).

[0089] Step 2: Preparation of 4-(4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)butanoic acid (IM-5)

[0090] Intermediate IM-5a (120 mg, 203 μmol) was dissolved in dichloromethane (2.00 mL), and trifluoroacetic acid (1.30 g, 11.4 mmol) was added, followed by stirring at 25°C for 12 hours. The reaction mixture was concentrated to dryness under reduced pressure to obtain the crude intermediate IM-5 as a yellow oily compound (100 mg), which was used directly without further purification.

[0091] Intermediate 6: N-(7-(2-hydroxypropan-2-yl)-2-(1-(2-oxoethyl)piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-6)

[0092] Step 1: Preparation of N-(2-(1-(2,2-diethoxyethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-6a)

[0093] Compound IM-1 (1.00 g, 2.23 mmol) and 2-bromo-1,1-diethoxyethane (880 mg, 4.47 mmol) were dissolved in acetone (2.00 mL), followed by the addition of potassium carbonate (926 mg, 6.70 mmol) and potassium iodide (185 mg, 1.12 mmol). The resulting mixture was heated to 80° C. and stirred for 12 hours. The mixture was concentrated to dryness under reduced pressure to afford intermediate IM-6a as a yellow solid (300 mg).

[0094] Step 2: Preparation of N-(7-(2-hydroxypropan-2-yl)-2-(1-(2-oxoethyl)piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-6)

[0095] Compound IM-6a (300 mg, 532 μmol) was dissolved in water (3.00 mL), and hydrochloric acid / 1,4-dioxane (4 M, 3.00 mL) was slowly added dropwise to the system at 25° C. The mixture was stirred at 60° C. for 12 hours and then concentrated to dryness in vacuo to obtain intermediate IM-6 as a white solid (430 mg).

[0096] Intermediate 7: N-(7-methoxy-2-(1-(2-oxoethyl)piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-7)

[0097] Step 1: Preparation of N-(2-(1-(2,2-diethoxyethyl)piperidin-4-yl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-7a)

[0098] Intermediate IM-1 (500 mg, 1.19 mmol) was dissolved in N,N-dimethylformamide (5.00 mL) at room temperature, followed by the addition of 2-bromo-1,1-diethoxyethane (469 mg, 2.38 mmol) and N,N-diisopropylethylamine (462 mg, 3.58 mmol). The mixture was microwaved at 100°C for 2 hours. The reaction mixture was concentrated to dryness under reduced pressure and purified by preparative HPLC (column: Phenomenex C18 75*30 mm*3 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 35%-65%, 8 min) to afford Intermediate IM-7a as a white solid (150 mg).

[0099] Step 2: Preparation of N-(7-methoxy-2-(1-(2-oxoethyl)piperidin-4-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-7)

[0100] Compound 2 (150 mg, 280 μmol) was added to water (2.00 mL), and then hydrochloric acid / dioxane (4.00 M, 2.00 mL) was slowly added at room temperature. The reaction mixture was warmed to 50° C. and stirred for 12 hours. The reaction mixture was concentrated to dryness to obtain intermediate IM-7 (140 mg, crude product), which was used directly in the next step without further purification.

[0101] Intermediate 8: N-(2-(1-(azetidin-3-yl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-8)

[0102] Step 1: Preparation of tert-butyl 3-(4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)azetidine-1-carboxylate (IM-8a)

[0103] Intermediate IM-1 (300 mg, 670 μmol) and tert-butyl 3-oxoazetidine-1-carboxylate (114 mg, 670 μmol) were dissolved in 1,2-dichloroethane (3.00 mL) and N,N-dimethylformamide (3.00 mL). Triethylamine (203 mg, 2.01 mmol) was added to the reaction mixture under nitrogen protection at 25 ° C. The reaction mixture was stirred at 25 ° C for 30 minutes. Sodium triacetoxyborohydride (284 mg, 1.34 mmol) and acetic acid (40.2 mg, 670 μmol) were then added to the reaction mixture, and the reaction mixture was stirred at 25 ° C for 11.5 hours. Water (5.00 mL) was added to quench the reaction, which was then extracted with ethyl acetate (10.0 mL × 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by HPLC (formic acid system) to obtain intermediate IM-8a as a yellow solid (100 mg).

[0104] Step 2: Preparation of N-(2-(1-(azetidin-3-yl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (IM-8)

[0105] Compound IM-8a (100 mg, 165 μmol) was dissolved in dioxane (1.00 mL). Hydrochloric acid / dioxane (4.00 M, 166 μL) was added to the reaction mixture at 25°C. The reaction mixture was stirred at 25°C for 12 hours. The reaction mixture was concentrated to dryness under reduced pressure to obtain intermediate IM-8 as a white solid (100.0 mg, hydrochloride salt).

[0106] Intermediate 9: 1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidine-4-carboxaldehyde (IM-9)

[0107] Step 1: Preparation of 5-(4-(dimethoxymethyl)piperidin-1-yl)-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (IM-9a)

[0108] 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (4.00 g, 14.4 mmol) was dissolved in dimethyl sulfoxide (40.0 mL) at 25°C, and N,N-diisopropylethylamine (3.74 g, 28.9 mmol) and 4-(dimethoxymethyl)piperidine (2.53 g, 15.9 mmol) were added to the reaction mixture. The reaction mixture was warmed to 90°C and stirred at 90°C for 15 hours. The reaction mixture was quenched by the addition of water (50.0 mL) at 25°C. The resulting mixture was extracted with ethyl acetate (50.0 mL × 3), and the combined organic phases were washed with brine (50.0 mL × 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-9a as a yellow solid (3.10 g, crude product).

[0109] Step 2: Preparation of 1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidine-4-carbaldehyde (IM-9)

[0110] Intermediate IM-9a (500 mg, 1.20 mmol) was added to formic acid (5.00 mL), and the reaction mixture was stirred at 25° C. for 12 hours. The reaction mixture was concentrated to give intermediate IM-9 as a yellow solid (400 mg, crude product), which was used directly without further purification.

[0111] Intermediate 10: 2-(2,6-dioxopiperidin-3-yl)-5-(piperazin-1-yl)isoindoline-1,3-dione (IM-10)

[0112] Step 1: Preparation of tert-butyl 4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazine-1-carboxylate (IM-10a)

[0113] 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (7.00 g, 25.3 mmol) was dissolved in dimethyl sulfoxide (60.0 mL) at 25°C. Tert-butyl piperazine-1-carboxylate (5.62 g, 30.1 mmol) and N,N-diisopropylethylamine (6.55 g, 50.6 mmol) were added to the reaction mixture. The resulting reaction mixture was heated to 95°C and stirred for 12 hours. Water (60.0 mL) was added to the reaction mixture. The resulting mixture was extracted with ethyl acetate (20.0 mL x 3). The combined organic phases were washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-10a as a yellow solid (8.00 g).

[0114] Step 2: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(piperazin-1-yl)isoindoline-1,3-dione (IM-10)

[0115] Intermediate IM-10a (2.00 g, 4.52 mmol) was dissolved in dichloromethane (28.0 mL) and trifluoroacetic acid (21.5 g, 189 mmol) was added. The reaction mixture was stirred at 25 ° C for 12 hours and then concentrated to dryness in vacuo to give intermediate IM-10 as a yellow solid (2.00 g, trifluoroacetate, crude product), which was used directly without further purification.

[0116] 1 HNMR (400MHz, DMSO-d6) δ11.10 (s, 1H), 7.76 (d, J = 8.5Hz, 1H), 7.46 (d, J = 2.1Hz, 1H), 7.31-7.35 (m, 1H), 5.03-5.16 (m, 1H), 3.65 (br s, 1H), 2.89 (s, 8H), 2.72-2.73 (m, 1H), 2.52-2.64 (m, 2H), 1.99-2.06 (m, 1H).

[0117] Intermediate 11: 2-(2,6-dioxopiperidin-3-yl)-5-(2,7-diazaspiro[3.5]nonane-2-yl)isoindoline-1,3-dione

[0118] Step 1: Preparation of tert-butyl 2-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,7-diazaspiro[3.5]nonane-7-carboxylate (IM-11a)

[0119] 2-(2,6-Dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (200 mg, 0.724 mmol) was dissolved in dimethyl sulfoxide (2.00 mL) at 25°C, followed by the addition of tert-butyl 2,7-diazaspiro[3.5]nonane-7-carboxylate (195 mg, 0.861 mmol) and N,N-diisopropylethylamine (187 mg, 1.45 mmol). The reaction mixture was heated to 95°C and stirred for 12 hours. Water (10 mL) was added to dilute the reaction mixture and the mixture was extracted with ethyl acetate (10 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-11a as a yellow solid (300 mg, crude product).

[0120] Step 2: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(2,7-diazaspiro[3.5]nonan-2-yl)isoindoline-1,3-dione (IM-11)

[0121] Compound IM-11a (300 mg, 0.621 mmol) was dissolved in dichloromethane (5.00 mL), and trifluoroacetic acid (2.91 g, 25.4 mmol) was added. The reaction mixture was stirred at 25°C for 12 hours and then concentrated under reduced pressure to obtain intermediate IM-11 as a yellow solid (300 mg, crude product), which was used directly without further purification.

[0122] Intermediate 12: 2-(2,6-dioxopiperidin-3-yl)-5-(2,7-diazaspiro[3.5]nonan-7-yl)isoindoline-1,3-dione (IM-12, hydrochloride)

[0123] Step 1: Preparation of tert-butyl 7-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,7-diazaspiro[3.5]nonane-2-carboxylate (IM-12a)

[0124] 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (500 mg, 1.81 mmol) was dissolved in dimethyl sulfoxide (5.00 mL), and tert-butyl 2,7-diazaspiro[3.5]nonane-2-carboxylate (450 mg, 1.99 mmol) and N,N-diisopropylethylamine (467 mg, 3.62 mmol) were added sequentially. The resulting mixture was stirred at 95°C for 12 hours. The reaction mixture was concentrated under reduced pressure to obtain intermediate IM-12a as a yellow solid (800 mg), which was used directly without further purification.

[0125] Step 2: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(2,7-diazaspiro[3.5]nonane-7-yl)isoindoline-1,3-dione (IM-12)

[0126] Compound 2 (400 mg, 0.828 mmol) was dissolved in 1,4-dioxane (5.00 mL) and then hydrochloric acid / 1,4-dioxane (5.00 g, 4.00 M) was added. The reaction mixture was stirred at 25° C. for 2 hours and then concentrated to dryness under reduced pressure to obtain intermediate IM-12 as a white solid (250 mg, hydrochloride).

[0127] 1 HNMR (400MHz, DMSO-d6) δ11.07 (s, 1H), 9.28 (br s, 2H), 7.66 (d, J=8.6Hz, 1H), 7.18-7.43 (m, 2H), 5.06 (dd, J=5.4, 12.9Hz, 1H), 3.73 (br t, J=6.1Hz, 4H), 3.41-3.52 (m, 4H), 2.80-2.94 (m, 1H), 2.58 (br d, J=16.1Hz, 1H), 2.96-1.06 (m, 1H), 1.79-1.89 (m, 4H).

[0128] Intermediate 13: 1-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)piperidine-4-carboxaldehyde (IM-13)

[0129] Step 1: Preparation of methyl 2-cyano-4-(4-(hydroxymethyl)piperidin-1-yl)benzoate (IM-13a)

[0130] Methyl 2-cyano-4-fluorobenzoate (10.0 g, 55.8 mmol) and 4-piperidinemethanol (9.64 g, 83.7 mmol) were dissolved in dimethyl sulfoxide (100 mL). N,N-diisopropylethylamine (20.4 g, 158 mmol) was added under a nitrogen atmosphere at 25°C. The reaction was heated to 110°C and stirred at 110°C for 16 hours. The residue was poured into ice water (200 mL) and stirred for 10 minutes. The aqueous phase was extracted with ethyl acetate (200 mL x 3). The combined organic phases were washed with brine (500 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain intermediate IM-13a as a yellow oil (18.0 g, crude product).

[0131] Step 2: Preparation of methyl 2-formyl-4-(4-(hydroxymethyl)piperidin-1-yl)benzoate (IM-13b)

[0132] Intermediate IM-13a (10.0 g, 36.4 mmol) was dissolved in a mixed solvent of glacial acetic acid (10.0 mL), pyridine (20.0 mL) and water (10.0 mL), and sodium hypophosphite monohydrate (50.3 g, 364 mmol) and Raney nickel (4.37 g, 51.0 mmol) were added under a nitrogen atmosphere at 25°C. The reaction system was replaced with hydrogen three times and then heated to 65°C. The reaction mixture was stirred under a hydrogen atmosphere at 65°C for 16 hours. The mixture was vacuum filtered and concentrated to give intermediate IM-13b as a yellow oil (4.50 g, crude product).

[0133] Step 3: Preparation of 3-(5-(4-(hydroxymethyl)piperidin-1-yl)-1-oxoisoindolin-2-yl)piperidine-2,6-dione (IM-13c)

[0134] Compound IM-13b (4.20 g, 15.1 mmol) and 3-aminopiperidine-2,6-dione (2.99 g, 18.1 mmol) were dissolved in dichloromethane (30.0 mL). N,N-diisopropylethylamine (5.87 g, 45.4 mmol), glacial acetic acid (8.82 g, 146 mmol) and sodium cyanoborohydride (2.86 g, 45.4 mmol) were added under nitrogen at 25 ° C. The reaction mixture was stirred at 25 ° C for 12 hours. Water (100 mL) was then added to quench the reaction and the pH was adjusted to 8 with saturated sodium bicarbonate aqueous solution. The resulting mixture was extracted with dichloromethane / methanol (10 / 1, 100 mL × 6). The combined organic phases were dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain compound IM-13c as a white solid (2.00 g).

[0135] Step 4: Preparation of 1-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)piperidine-4-carbaldehyde (IM-13)

[0136] Compound IM-13c (0.50 g, 1.40 mmol) was dissolved in dichloromethane (20.0 mL) and Dess-Martin periodinane (593 mg, 1.40 mmol) was added under nitrogen at 25°C. The reaction mixture was stirred at 35°C for 1 hour. The reaction mixture was filtered, and the filtrate was concentrated under vacuum. The residue was purified by HPLC (formic acid conditions) to obtain compound IM-13 as a yellow solid (1.00 g, crude product).

[0137] Intermediate 14: 2-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)acetaldehyde (IM-14)

[0138] Step 1: Preparation of 5-(4-(2,2-diethoxyethyl)piperazin-1-yl)-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (IM-14a)

[0139] Intermediate IM-10 (1.00 g, 2.92 mmol) was dissolved in N,N-dimethylformamide (8.00 mL) at room temperature, followed by the addition of 2-bromo-1,1-diethoxyethane (1.15 g, 5.84 mmol) and N,N-diisopropylethylamine (1.13 g, 8.76 mmol). The reaction mixture was heated to 100°C and stirred for 12 hours. The reaction mixture was diluted with water (30.0 mL) and extracted with ethyl acetate (30.0 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by preparative HPLC (column: Phenomenex luna C18 80*40 mm*3 μm; mobile phase: [H2O(FA)-ACN]; B%: 1%-35%, 8 min) to afford Intermediate IM-14a as a yellow solid (200 mg).

[0140] Step 2: Preparation of 2-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)acetaldehyde (IM-14)

[0141] Intermediate IM-14a (100 mg, 218.10 μmol) was dissolved in formic acid (2.00 mL), and the reaction mixture was stirred at 65° C. for 12 hours. The reaction mixture was concentrated to dryness to give intermediate IM-14 as a yellow solid (40.0 mg, crude).

[0142] Intermediate 15: 1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidine-4-carboxaldehyde (IM-15)

[0143] Step 1: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5,6-difluoroisoindoline-1,3-dione (IM-15a)

[0144] 3-Aminopiperidine-2,6-dione hydrochloride (9.83 g, 59.7 mmol) was dissolved in toluene (100 mL). Triethylamine (16.4 g, 162 mmol) and 5,6-difluoroisobenzofuran-1,3-dione (10.0 g, 54.3 mmol) were added at room temperature. The reaction mixture was stirred at 60°C for 12 hours. The reaction mixture was diluted with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-15a as a yellow solid (4.50 g, crude product).

[0145] Step 2: Preparation of 5-(4-(dimethoxymethyl)piperidin-1-yl)-2-(2,6-oxopiperidin-3-yl)-6-fluoroisoindoline-1,3-dione (IM-15b)

[0146] IM-15a (4.50 g, 13.6 mmol) was dissolved in dimethyl sulfoxide (40.0 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (3.51 g, 27.1 mmol) and 4-(dimethoxymethyl)piperidine (2.16 g, 13.6 mmol). The reaction mixture was stirred at 90°C for 12 hours. The reaction mixture was diluted with water (40.0 mL) and extracted with ethyl acetate (40.0 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to afford intermediate IM-15b as a yellow solid (2.50 g, crude product).

[0147] Step 3: Preparation of 1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidine-4-carbaldehyde (IM-15)

[0148] Intermediate IM-15b (1.00 g, 2.31 mmol) was dissolved in tetrahydrofuran (10.0 mL) and water (2.00 mL) at room temperature, and then pyridine p-toluenesulfonate (1.16 g, 4.61 mmol) was added. The reaction mixture was stirred at 70° C. for 12 hours and then concentrated to give intermediate IM-15 as a yellow solid (500 mg), which was used directly without further purification.

[0149] Intermediate 16: 2-(1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)acetaldehyde (IM-16)

[0150] Step 1: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(4-(2-hydroxyethyl)piperidin-1-yl)isoindoline-1,3-dione (IM-16a)

[0151] 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (2.00 g, 7.24 mmol) was dissolved in dimethyl sulfoxide (10.0 mL), followed by the addition of N,N-diisopropylethylamine (1.87 g, 14.4 mmol) and 2-(piperidin-4-yl)ethan-1-ol (1.03 g, 7.96 mmol). The reaction mixture was stirred at 90°C for 12 hours. Water (10.0 mL) was slowly added to quench the reaction, and the mixture was extracted with ethyl acetate (10.0 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography to afford Intermediate IM-16a as a yellow solid (1.10 g).

[0152] Step 2: 2-(1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)acetaldehyde

[0153] Intermediate IM-16a (1.10 g, 2.85 mmol) was dissolved in dichloromethane (10.0 mL) at 25 ° C, and then Dess-Martin periodinane (1.21 g, 2.85 mmol) was added. The reaction mixture was stirred at 25 ° C for 2 hours. Water (10.0 mL) was slowly added to quench the reaction and extracted with ethyl acetate (30 mL × 3). The combined organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain intermediate IM-16 as a yellow solid (600 mg), which was used directly without further purification.

[0154] Intermediate 17: 3-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)propyl methanesulfonate (IM-17)

[0155] Step 1: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(4-(3-hydroxypropyl)piperazin-1-yl)isoindoline-1,3-dione (IM-17a)

[0156] Dissolve 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (1.72 g, 6.24 mmol) in dimethyl sulfoxide (10.0 mL), then add N,N-diisopropylethylamine (1.61 g, 12.4 mmol) and 3-(piperazin-1-yl)propan-1-ol (900 mg, 6.24 mmol). Stir the reaction mixture at 90°C for 12 hours. Add water (10.0 mL) to dilute the reaction, and extract the aqueous layer with ethyl acetate (10 mL x 3). Wash the combined organic phases with saturated brine, dry over anhydrous sodium sulfate, filter, and concentrate under reduced pressure. The residue is purified by column chromatography (formic acid system) to yield Intermediate IM-17a as a yellow solid (1.50 g).

[0157] Step 2: Preparation of 3-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)propyl methanesulfonate (IM-17)

[0158] Compound IM-17a (1.00 g, 2.50 mmol) was dissolved in tetrahydrofuran (10.0 mL), followed by the addition of triethylamine (631 mg, 6.24 mmol) and methanesulfonic anhydride (870 mg, 4.99 mmol). The reaction mixture was stirred at 25°C for 12 hours. The reaction mixture was diluted with water (10 mL) and extracted with ethyl acetate (10 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to afford intermediate IM-17 as a yellow solid (600 mg, crude product).

[0159] Intermediate 18: 2-(2,6-dioxopiperidin-3-yl)-5-(4-oxopiperidin-1-yl)isoindoline-1,3-dione (IM-18)

[0160] Piperidin-4-one (490 mg, 3.62 mmol) was dissolved in dimethyl sulfoxide (10.0 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (935 mg, 7.24 mmol) and 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (1.00 g, 3.62 mmol). The reaction mixture was heated to 90°C and stirred for 12 hours. The reaction mixture was cooled to 25°C, water (10.0 mL) was added, and then extracted with ethyl acetate (10.0 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography to afford Intermediate IM-18 as a yellow oil (310 mg).

[0161] Intermediate 19: 2-(2,6-dioxopiperidin-3-yl)-5-(2,6-diazaspiro[3.3]hept-2-yl)isoindoline-1,3-dione trifluoroacetate (IM-19)

[0162] Step 1: Preparation of tert-butyl 6-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,6-diazaspiro[3.3]heptane-2-carboxylate (IM-19a)

[0163] 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (3.00 g, 10.8 mmol) and tert-butyl 2,6-diazaspiro[3.3]heptane-2-carboxylate (2.15 g, 10.8 mmol) were dissolved in dimethyl sulfoxide (30.0 mL), followed by the addition of N,N-diisopropylethylamine (4.21 g, 32.5 mmol). The reaction mixture was heated to 95°C and stirred for 12 hours. 20.0 mL of water was added at 5°C to quench the reaction, and the resulting mixture was extracted with 45.0 mL (15.0 mL x 3) of dichloromethane. The organic layer was washed with an aqueous sodium chloride solution (5.00 mL x 3), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-19a as a yellow oil (1.20 g).

[0164] Step 2: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(2,6-diazaspiro[3.3]hept-2-yl)isoindoline-1,3-dione trifluoroacetate (IM-19)

[0165] Intermediate IM-19a (200 mg, 440 μmol) was dissolved in dichloromethane (2.00 mL), and trifluoroacetic acid (3.07 g, 26.9 mmol) was added. The reaction mixture was stirred at 25° C. for 12 hours and then concentrated under reduced pressure to give intermediate IM-19a as a white solid (150 mg).

[0166] Intermediate 20: 2-(4-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)ethyl methanesulfonate (IM-20)

[0167] Step 1: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-fluoro-6-(4-(2-hydroxyethyl)piperazin-1-yl)isoindoline-1,3-dione (IM-20a)

[0168] At 25 ° C, intermediate IM-15a (1.00 g, 3.40 mmol) and 2-(piperazine-1-yl) ethane-1-ol (486 mg, 3.74 mmol) were dissolved in dimethyl sulfoxide (10.0 mL), and N, N-diisopropylethylamine (439 mg, 3.40 mmol) was added to the reaction mixture. The reaction mixture was heated to 90 ° C and stirred for 12 hours. At 25 ° C, the reaction was quenched with 20.0 mL of water and then extracted with ethyl acetate (30.0 mL × 3). The combined organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain intermediate IM-20a as a yellow solid (1.00 g, 2.97 mmol).

[0169] Step 2: Preparation of 2-(4-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)ethyl methanesulfonate (IM-20)

[0170] Intermediate IM-20a (200 mg, 494 μmol) was dissolved in dichloromethane (2.00 mL) and triethylamine (125 mg, 1.24 mmol) was added to the reaction mixture at 25°C. The reaction mixture was stirred at 25°C for 30 minutes, and then methanesulfonic anhydride (129 mg, 741 μmol) was added to the reaction mixture. The reaction mixture was stirred at 25°C for 11.5 hours. The reaction mixture was slowly poured into water (10 mL) and then extracted with dichloromethane (5 mL x 3). The combined organic phases were washed with brine (5.00 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to afford intermediate IM-20 as a yellow solid (200 mg, crude product), which was used directly without further purification.

[0171] Intermediate 21: 3-(1-oxo-5-(piperazin-1-yl)isoindolin-2-yl)piperidine-2,6-dione hydrochloride (IM-21)

[0172] Step 1: Preparation of methyl 4-fluoro-2-formylbenzoate (IM-21a)

[0173] Pyridine (15.0 g, 190 mmol) was added to water (50.0 mL) and acetic acid (50 mL). Raney nickel (7.72 g, 90.1 mmol) was added under nitrogen, followed by a solution of methyl 2-cyano-4-fluorobenzoate (5.00 g, 27.9 mmol) in tetrahydrofuran (50.0 mL). The reaction mixture was warmed to 65° C. and stirred for 16 hours. Water (50.0 mL) was slowly added to quench the reaction, and the aqueous layer was extracted with ethyl acetate (50 mL × 3). The combined organic layers were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-21a as a white solid (3.00 g, crude product).

[0174] Step 2: Preparation of tert-butyl 4-(3-formyl-4-(methoxyformyl)phenyl)piperazine-1-carboxylate (IM-21b)

[0175] Boc-piperazine (2.61 g, 14.0 mmol) was dissolved in dimethyl sulfoxide (30.0 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (6.39 g, 49.4 mmol) and intermediate IM-21a (3.00 g, 16.4 mmol). The reaction mixture was heated to 100°C and stirred for 16 hours. Water (30.0 mL) was slowly added to quench the reaction. The aqueous layer was extracted with ethyl acetate (30 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to afford intermediate IM-21b as a yellow solid (1.40 g).

[0176] 1 HNMR: (400MHz, DMSO-d6) δ10.49 (s, 1H), 7.84 (d, J=8.6Hz, 1H), 7.12-7.26 (m, 2H), 3.8 4(s, 2H), 3.64-3.70(m, 1H), 3.42-3.50(m, 4H), 3.34-3.42(m, 4H), 1.44-1.41(m, 9H).

[0177] Step 3: Preparation of tert-butyl 4-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)piperazine-1-carboxylate (IM-21c)

[0178] 3-Aminopiperidine-2,6-dione hydrochloride (992 mg, 6.03 mmol) was dissolved in dimethyl sulfoxide (10.0 mL). N,N-diisopropylethylamine (1.56 g, 12.0 mmol) was added, followed by acetic acid (1.54 g, 25.6 mmol), sodium acetate borohydride (1.70 g, 8.04 mmol), and Intermediate IM-21b (1.40 g, 4.02 mmol). The reaction mixture was stirred at 25°C for 12 hours. Water (30 mL) was slowly added to quench the reaction. The aqueous layer was extracted with ethyl acetate (20 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain Intermediate IM-21c as a yellow solid (900 mg).

[0179] Step 4: Preparation of 3-(1-oxo-5-(piperazin-1-yl)isoindolin-2-yl)piperidine-2,6-dione hydrochloride (IM-21)

[0180] Intermediate IM-21c (182 mg, 424 μmol) was dissolved in dioxane (2.00 mL) and hydrochloric acid / dioxane (4 M, 1.82 mL) was added. The reaction mixture was stirred at 25° C. for 12 hours. The reaction mixture was concentrated to give intermediate IM-21 as an off-white solid (160 mg).

[0181] Intermediate 22: 3-(1-oxo-6-(piperazin-1-yl)isoindolin-2-yl)piperidine-2,6-dione hydrochloride (IM-22)

[0182] Step 1: Preparation of tert-butyl 4-(4-formyl-3-(methoxyformyl)phenyl)piperazine-1-carboxylate (IM-22a)

[0183] Boc-piperazine (869 mg, 4.67 mmol) was dissolved in dimethyl sulfoxide (8.00 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (2.13 g, 16.4 mmol) and methyl 5-fluoro-2-formylbenzoate (1.00 g, 5.49 mmol). The reaction mixture was heated to 80°C and stirred for 16 hours. Water (30 mL) was slowly added to quench the reaction, and the aqueous layer was extracted with ethyl acetate (10 mL x 3). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to afford intermediate IM-22a as a yellow oil (1.80 g, crude product).

[0184] Step 2: Preparation of tert-butyl 4-(2-(2,6-dioxopiperidin-3-yl)-3-oxoisoindolin-5-yl)piperazine-1-carboxylate (IM-22b)

[0185] 3-Aminopiperidine-2,6-dione hydrochloride (935 mg, 5.68 mmol) was dissolved in N,N-dimethylformamide (5 mL). N,N-diisopropylethylamine (1.34 g, 10.3 mmol) was added at room temperature, followed by acetic acid (3.10 g, 51.6 mmol), sodium acetate borohydride (3.29 g, 15.5 mmol), and Intermediate IM-22a (1.80 g, 5.17 mmol). The reaction mixture was stirred at 25°C for 12 hours. Water (20 mL) was slowly added to quench the reaction, and the aqueous layer was extracted with ethyl acetate (10 mL x 3). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to afford Intermediate IM-22b as a yellow oil (650 mg, crude product).

[0186] Step 3: Preparation of 3-(1-oxo-6-(piperazin-1-yl)isoindolin-2-yl)piperidine-2,6-dione hydrochloride (IM-22)

[0187] Intermediate IM-22b (650 mg, 1.52 mmol) was dissolved in ethyl acetate (2.00 mL). Hydrochloric acid / ethyl acetate (4 M, 2.00 mL) was added at room temperature and stirred for 2 hours. The reaction mixture was concentrated to give intermediate IM-22 as a yellow solid (220 mg).

[0188] Intermediate 23: 1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1-oxoisoindolin-5-yl)piperidine-4-carbaldehyde (IM-23)

[0189] Step 1: Preparation of methyl 4-bromo-2-(bromomethyl)-5-fluorobenzoate (IM-23a)

[0190] Methyl 4-bromo-5-fluoro-2-methylbenzoate (4.50 g, 18.2 mmol) was dissolved in dichloroethane (25.0 mL). N-bromosuccinimide (3.53 g, 19.8 mmol) and azobisisobutyronitrile (149 mg, 910 μmol) were added sequentially at room temperature, and the reaction mixture was stirred at 80°C for 12 hours. The reaction mixture was diluted with water (30.0 mL) and extracted with ethyl acetate (30.0 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel) to afford Intermediate IM-23a as a yellow solid (2.50 g, crude product).

[0191] Step 2: Preparation of 3-(5-bromo-6-fluoro-1-oxoisoindolin-2-yl)piperidine-2,6-dione (IM-23b)

[0192] Compound IM-23a (2.30 g, 7.06 mmol) was dissolved in acetonitrile (15.0 mL). 3-Aminopiperidine-2,6-dione hydrochloride (1.39 g, 8.47 mmol) and N,N-diisopropylethylamine (2.74 g, 21.1 mmol) were added sequentially at 25°C. The reaction mixture was stirred at 80°C for 12 hours. The reaction mixture was diluted with water (30.0 mL) and extracted with ethyl acetate (30.0 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel) to afford intermediate IM-23b as a brownish-black solid (1.00 g).

[0193] MS (ESI+) m / z 342.0 [M+H] + .

[0194] Step 3: Preparation of 3-(5-(4-(dimethoxymethyl)piperidin-1-yl)-6-fluoro-1-oxoisoindolin-2-yl)piperidine-2,6-dione (IM-23c)

[0195] Compound IM-23b (1.00 g, 2.93 mmol) was dissolved in dimethyl sulfoxide (10.0 mL). 4-(Dimethoxymethyl)piperidine, cesium carbonate (2.87 g, 8.79 mmol), and Pd-PEPPSI-IPentCl (285 mg, 293 μmol) were added sequentially at room temperature. The reaction mixture was stirred at 80°C for 12 hours. The reaction mixture was diluted with water (20.0 mL) and extracted with ethyl acetate (20.0 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel) to afford intermediate IM-23c as a yellow solid (200 mg, crude product).

[0196] MS (ESI+) m / z 420.1 [M+H] + .

[0197] Step 4: Preparation of 1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1-oxoisoindolin-5-yl)piperidine-4-carbaldehyde (IM-23)

[0198] Intermediate 23c (200 mg, 47.6 μmol) was dissolved in formic acid (2.00 mL) at room temperature. The reaction mixture was stirred at 55° C. for 12 hours and then concentrated under reduced pressure to give Intermediate IM-23 as a yellow oil (150 mg), which was used in the next step without purification.

[0199] MS (ESI+) m / z 374.1 [M+H] + .

[0200] Intermediate 24: 3-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-3-azabicyclo[3.1.0]hexane-6-carbaldehyde (IM-24)

[0201] Step 1: Preparation of 3-tert-butyl 6-ethyl 3-azabicyclo[3.1.0]hexane-3,6-dicarboxylate (IM-24a)

[0202] Ethyl diazoacetate (10.0 g, 59.0 mmol) and rhodium acetate dimer (261 mg, 590 μmol) were dissolved in dichloromethane (100 mL), and tert-butyl 2,5-dihydro-1H-pyrrole-1-carboxylate (10.1 g, 88.6 mmol) was slowly added dropwise. After the addition, the resulting reaction mixture was stirred at 25°C for 12 hours and then concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) and then purified by preparative HPLC (column: Welch Xtimate C18 250*70 mm*10 μm; mobile phase: [H2O(10 mM NH4HCO3)-ACN]; gradient: 40%-70% B over 18.0 min) to obtain intermediate IM-24a as a yellow oil (500 mg).

[0203] Step 2: Preparation of tert-butyl 6-(hydroxymethyl)-3-azabicyclo[3.1.0]hexane-3-carboxylate (IM-24b)

[0204] At 0°C, intermediate IM-24a (500 mg, 1.96 mmol) was dissolved in tetrahydrofuran (10.0 mL) and lithium aluminum tetrahydride (2.50 M, 1.96 mL) was slowly added dropwise. The reaction mixture was stirred at 25°C for 2 hours, then quenched with water (20 mL) at 0°C and extracted with dichloromethane (90 mL). The organic layer was washed with aqueous sodium chloride (30 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-24b as a yellow solid compound (250 mg).

[0205] Step 3: Preparation of (3-azabicyclo[3.1.0]hexan-6-yl)methanol (IM-24c)

[0206] Intermediate IM-24b (240 mg, 1.13 mmol) was dissolved in 1,4-dioxane (10.0 mL) at 25° C., and then hydrochloric acid / dioxane (4 M, 8.44 mL) was added. The reaction mixture was stirred for 2 hours and then concentrated under reduced pressure to give intermediate IM-24c as a white solid (200 mg), which was used directly in the next step without further purification.

[0207] 1HNMR: (400MHz, CDCl3) δ 3.49 (brd, J=6.9Hz, 2H), 2.99 (brd, J=11.3Hz, 2H), 2.87 (brd, J=11.0Hz, 2H), 2.33 (brs, 2H), 1.34 (brs, 2H), 0.80-1.00 (m, 1H).

[0208] Step 4: Preparation of 2-(2,6-dioxopiperidin-3-yl)-5-(6-(hydroxymethyl)-3-azabicyclo[3.1.0]hexane-3-yl)isoindoline-1,3-dione (IM-24d)

[0209] Intermediate IM-24c (200 mg, 883 μmol) and 2-(2,6-dioxopiperidin-3-yl)-5-fluoroisoindoline-1,3-dione (244.10 mg, 883 μmol) were dissolved in N-methylpyrrolidone (5.00 mL) at room temperature, followed by the addition of diisopropylethylamine (342 mg, 2.65 mmol). The resulting reaction mixture was heated to 80°C and stirred for 12 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by preparative HPLC (column: Waters Xbridge Prep OBD C18 150*40 mm*10 μm; mobile phase: [H2O(10 mM NH4HCO3)-ACN]; gradient: 2%-40% B over 8.0 min) to afford Intermediate IM-24d as a yellow solid (150 mg).

[0210] Step 5: Preparation of 3-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-3-azabicyclo[3.1.0]hexane-6-carbaldehyde (IM-24)

[0211] Intermediate IM-24d (150 mg, 391 μmol) was dissolved in dichloromethane (5.00 mL) at room temperature, and Dess-Martin periodinane (342 mg, 810 μmol) was added. The reaction mixture was stirred at 25°C for 12 hours, then quenched with water (20 mL) at 0°C and extracted with dichloromethane (90.0 mL). The organic layer was washed with aqueous sodium chloride (30 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure to obtain intermediate IM-24 as a yellow solid (100 mg).

[0212] Example 1:

[0213] N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0214] IM-1 (100 mg, 206 μmol) and compound IM-9 (76.3 mg, 206 μmol) were dissolved in N,N-dimethylformamide (1.00 mL) and tetrahydrofuran (1.00 mL) at 25°C, followed by the addition of sodium acetate (25.4 mg, 309 μmol). After stirring for 30 minutes, sodium triacetoxyborohydride (131 mg, 619 μmol) and glacial acetic acid (37.2 mg, 619 μmol) were added. The reaction mixture was stirred at 25°C for 2 hours. The reaction mixture was filtered and concentrated. The resulting residue was purified by preparative HPLC (column: Waters Xbridge BEH C18 100*30 mm*10 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 30%-60%, 8 min) to yield compound 1 as a yellow solid (30.0 mg).

[0215] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.08 (s, 1H), 9.54 (s, 1H), 8.34-8.50 (m, 2H), 8.19 (d, J =7.6Hz, 1H), 7.79 (s, 1H), 7.65 (d, J = 8.6Hz, 1H), 7.41 (s, 1H), 7.31 (s, 1H), 7.23 (br d, J=7.7Hz, 1H), 6.16 (s, 1H), 5.06 (dd, J=5.4, 12.8Hz, 1H), 4.05 (br d, J=12.0Hz, 2H), 2.78-3.08(m, 5H), 2.51-2.73(m, 4H), 2.20(br s, 1H), 1.92-2.02(m, 4H), 1.81(br d, J=13.6Hz, 2H), 1.69(br d, J=10.5Hz, 2H), 1.60 (s, 6H), 1.41-1.55 (m, 1H), 1.06-1.28 (m, 3H).

[0216] MS (ESI+) m / Z 801.3 [M+H] + .

[0217] Example 2:

[0218] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)-2-oxoethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0219] Intermediate IM-3 (100 mg, 197 μmol) and intermediate IM-10 (54.1 mg, 158 μmol) were dissolved in N,N-dimethylformamide (2.00 mL) at 25°C, followed by the addition of N,N-diisopropylethylamine (102 mg, 791 μmol). The reaction mixture was stirred at 25°C for 30 minutes. O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronium hexafluorophosphonate (112 mg, 296 μmol) was then added to the reaction mixture, and the reaction mixture was stirred at 25°C for 2.5 hours. The reaction mixture was concentrated under reduced pressure. The obtained residue was purified by high performance liquid chromatography (chromatographic column: Waters Xbridge BEH C18 100*30mm*10μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 40%-60%, 8 min) to obtain compound 2 as a yellow solid (28.0 mg).

[0220] 1 HNMR (400MHz, DMSO-d6) δ12.01-12.40 (m, 1H), 9.54 (s, 1H), 8.36-8.47 (m, 2H), 8.19 (d, J=7.6Hz, 1H), 7.79 (s, 1H), 7.71 (d, J=8.5Hz, 1H), 7.40 (br d, J=9.9Hz, 2H), 7.29 (br d, J=8.7Hz, 1H), 5.08 (br dd, J=5.2, 12.9Hz, 1H), 3.78 (br s, 2H), 3.47-3.65 (m, 6H), 3.23 (br s, 4H), 2.84-2.96 (m, 3H), 2.58-2.70 (m, 2H), 2.12-2.21 (m, 2H), 1.93-2.05 (m, 3H), 1.65-1.74 (m, 2H), 1.60 (s, 6H), 1.22 (br d, J=7.2Hz, 1H).

[0221] MS (ESI+) m / Z 830.3 [M+H] + .

[0222] Example 3:

[0223] N-(2-(1-(3-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)-3-oxopropyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0224] Compound IM-4 (210 mg, 577 μmol) and compound IM-10 (158 mg, 461 μmol) were dissolved in N,N-dimethylformamide (4.00 mL) at 25°C, followed by the addition of N,N-diisopropylethylamine (298 mg, 2.31 mmol). The reaction mixture was stirred at 25°C for 30 minutes, followed by the addition of O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronium hexafluorophosphonate (329 mg, 866 μmol). The reaction mixture was stirred at 25°C for 2.5 hours and then concentrated under reduced pressure. The resulting residue was purified by high performance liquid chromatography (formic acid system) to yield compound 3 as a yellow solid (30.0 mg).

[0225] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.08 (s, 1H), 9.54 (s, 1H), 8.34-8.50 (m, 2H), 8.14-8.22 (m, 1H), 7.64- 7.87 (m, 2H), 7.33-7.45 (m, 2H), 7.26 (dd, J=2.0, 8.4Hz, 1H), 6.16 (s, 1H), 5.08 (dd, J=5.3, 12.8Hz, 1H), 3.64 (br d, J=4.4Hz, 5H), 3.04-3.13(m, 3H), 2.81-2.94(m, 2H), 2.54-2.80(m, 8H), 2.34(br d, J=9.4Hz, 2H), 1.96-2.07 (m, 3H), 1.68-1.79 (m, 2H), 1.60 (s, 6H).

[0226] MS (ESI+) m / Z 844.4 [M+H] + .

[0227] Example 4:

[0228] N-(2-(1-(4-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)-4-oxobutyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0229] Intermediate IM-5 (100 mg, 187 μmol) was dissolved in dimethylformamide (2.00 mL) at 25°C, followed by the addition of O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronium hexafluorophosphonate (142 mg, 374 μmol) and N,N-diisopropylethylamine (121 mg, 937 μmol). After stirring for 30 minutes, Intermediate IM-10 (77.00 mg, 224 μmol) was added, and the reaction mixture was stirred at 25°C for 11.5 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by preparative HPLC (column: Waters Xbridge BEH C18 100*30 mm*10 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 25%-55%, 8 min) to afford compound 4 as a yellow solid (8.00 mg).

[0230] 1 HNMR (400MHz, DMSO-d6) δ12.23 (s, 1H), 11.09 (s, 1H), 9.56 (s, 1H), 8.33-8.50 ( m, 2H), 8.14-8.21 (m, 1H), 7.85 (s, 1H), 7.71 (d, J=8.4Hz, 1H), 7.24-7.42 (m, 2H ), 6.19(s, 1H), 4.94-5.19(m, 1H), 3.58-3.68(m, 8H), 2.70-2.97(m, 8H), 2.54- 2.64(m, 2H), 2.29-2.46(m, 2H), 2.08-2.16(m, 2H), 1.98-2.05(m, 1H), 1.85(br s, 5H), 1.60 (s, 6H).

[0231] MS (ESI+) m / z 858.3 [M+H] + .

[0232] Example 5:

[0233] N-(2-(1-(2-(2-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,7-diazaspiro[3.5]nonan-7-yl)-2-oxoethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0234] Intermediate IM-3 (100 mg, 197 μmol) was dissolved in dimethylformamide (5.00 mL) at room temperature, followed by the addition of O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronium hexafluorophosphonate (107 mg, 282 μmol) and N,N-diisopropylethylamine (109 mg, 847 μmol). The reaction mixture was stirred for 15 minutes, followed by the addition of Intermediate IM-11 (54.0 mg, 141 μmol). The reaction mixture was stirred at room temperature for 12 hours and then concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (column: Waters Xbridge BEH C18 250*50 mm*10 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 25%-55% over 10 min) to afford compound 5 as a yellow solid (14.7 mg).

[0235] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.06 (s, 1H), 9.54 (s, 1H), 8.50-8.33 (m, 2H), 8.1 9 (d, J=7.8Hz, 1H), 7.79 (s, 1H), 7.65 (d, J=8.3Hz, 1H), 7.41 (s, 1H), 6.77 (s, 1H), 6.65 (br d, J=8.4Hz, 1H), 6.14 (s, 1H), 5.05 (dd, J=5.3, 12.9Hz, 1H), 3.82 (s, 4H), 3.42- 3.59(m, 2H), 2.81-2.96(m, 4H), 2.52-2.71(m, 6H), 2.09-2.19(m, 2H), 1.97(br d, J=10.8Hz, 3H), 1.81 (br s, 2H), 1.65-1.75 (m, 4H), 1.60 (s, 6H).

[0236] MS (ESI+) m / z 870.3 [M+H] + .

[0237] Example 6:

[0238] N-(2-(1-(2-(7-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,7-diazaspiro[3.5]nonan-2-yl)-2-oxoethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0239] Intermediate IM-3 (200 mg, 395 μmol) and O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronium hexafluorophosphonate (90.7 mg, 238 μmol) were dissolved in dichloromethane (3.00 mL), and the reaction mixture was stirred at 25°C for 1 hour. Intermediate IM-12 (100 mg, 238 μmol) and N,N-diisopropylethylamine (30.8 mg, 238 μmol) were added sequentially, and the resulting reaction mixture was stirred at 25°C for 2 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by preparative HPLC (column: Waters Xbridge BEH C18 250*50 mm*10 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 25%-55%, 10 min) to yield compound 6 as a yellow solid (17.8 mg).

[0240] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.08 (br s, 1H), 9.53 (s, 1H), 8.31-8.51 (m, 2H), 8.18 (d, J=7.7Hz, 1H), 7.79 (s, 1H), 7.65 (d, J=8. 4Hz, 1H), 7.21-7.46 (m, 3H), 6.16 (s, 1H), 5.05 (s, 1H), 3.98 (s, 2H), 3.63 (s, 2H), 3.47 (br s, 4H), 2.94-3.07 (m, 2H), 2.79-2.93 (m, 3H), 2.60 (br d, J=2.7Hz, 3H), 2.16 (br s, 2H), 1.96 (br d, J=13.7Hz, 3H), 1.53-1.82 (m, 12H).

[0241] MS (ESI+) m / z 870.3 [M+H] + .

[0242] Example 7:

[0243] N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0244] Intermediate IM-1 (100 mg, 223 μmol) and intermediate IM-13 (79.4 mg, 223 μmol) were dissolved in N,N-dimethylformamide (2.00 mL) and tetrahydrofuran (2.00 mL) at 25° C., and sodium acetate (27.5 mg, 335 μmol) was added, and the reaction mixture was stirred at 25° C. for 30 minutes. Sodium triacetoxyborohydride (27.5 mg, 335 μmol) and glacial acetic acid (40.2 mg, 670 μmol) were added, and the reaction mixture was stirred at 25° C. for a further 11.5 hours. The reaction mixture was concentrated under reduced pressure, and the residue was purified by preparative high performance liquid chromatography (chromatographic column: Waters Xbridge BEH C18 100*30mm*10μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 35%-65%, 8 min) to obtain compound 7 as a white solid (42.0 mg).

[0245] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 10.93 (br s, 1H), 9.54 (s, 1H), 8.48-8.35 (m, 2H), 8.19 (br d, J=7.8Hz, 1H), 7.78 (s, 1H), 7.50 (br d, J=8.6Hz, 1H), 7.41 (s, 1H), 7.10-6.98 (m, 2H), 6.15 (s, 1H), 5.04 (br dd, J=4.9, 13.1Hz, 1H), 4.32 (br d, J=17.0Hz, 1H), 4.19 (br d, J=16.6Hz, 1H), 3.87(br d, J=11.9Hz, 2H), 2.97-2.77(m, 5H), 2.70-2.54(m, 2H), 2.42-2.31(m, 1H), 2.22-2.14(m, 2H), 2.06-1.91(m, 5H), 1.80(br d, J=10.9Hz, 3H), 1.72-1.65 (m, 2H), 1.63-1.54 (m, 6H), 1.23 (br s, 1H), 1.19-1.10 (m, 1H).

[0246] MS (ESI+) m / z 787.4 [M+H] + .

[0247] Example 8:

[0248] N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0249] Intermediate IM-2 (400 mg, 953 μmol) and intermediate IM-9 (422 mg, 1.14 mmol) were dissolved in N,N-dimethylformamide (4.00 mL), followed by the addition of sodium acetate (117 mg, 1.43 mmol). The reaction mixture was stirred for 30 minutes, followed by the addition of sodium triacetoxyborohydride (606 mg, 2.86 mmol) and acetic acid (171 mg, 2.86 mmol). The reaction mixture was stirred at 25°C for 12 hours, then diluted with water (10.0 mL). The resulting mixture was extracted with ethyl acetate (10 mL x 3), and the combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (chromatographic column: Phenomenex luna C18 80*40mm*3μm; mobile phase: [H2O(FA)-ACN]; B%: 1%-35%, 8 min) to obtain compound 8 as a yellow solid (12.0 mg).

[0250] 1 HNMR (400MHz, DMSO-d6) δ11.07 (s, 1H), 10.19 (s, 1H), 9.35 (s, 1H), 8.49-8.37 (m, 2H), 8.21-8.26 (m, 1H), 7.65 (t, J=4.2Hz, 2H), 7.31 ( d, J=1.6Hz, 1H), 7.21-7.27(m, 1H), 7.07(s, 1H), 5.02-5.11(m, 1H), 3.97-4.07(m, 5H), 2.89-3.03(m, 5H), 2.54-2.66(m, 3H), 2.19(br d, J=6.6Hz, 2H), 1.93-2.07 (m, 5H), 1.77-1.86 (m, 3H), 1.61-1.72 (m, 2H), 1.12-1.26 (m, 2H).

[0251] MS (ESI+) m / z 773.2 [M+H] + .

[0252] Example 9:

[0253] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0254] Intermediate IM-1 (23.2 mg, 52.0 μmol) and intermediate IM-14 (20.0 mg, 52.0 μmol) were dissolved in N,N-dimethylformamide (1.00 mL) and 1,2-dichloroethane (1.00 mL) at 25°C. N,N-diisopropylethylamine (20.1 mg, 156 μmol) was added, and the reaction mixture was stirred at 25°C for 30 minutes. Glacial acetic acid (9.37 mg, 156 μmol) and sodium triacetoxyborohydride (16.5 mg, 78.0 μmol) were added, and the reaction mixture was stirred at 25°C for 11.5 hours. Water (3.00 mL) was added, and the resulting mixture was extracted with ethyl acetate (5.00 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (formic acid system) to yield compound 9 as a yellow solid (2.00 mg).

[0255] 1 HNMR (400MHz, DMSO-d6) δ12.23 (s, 1H), 11.08 (br s, 1H), 9.54 (s, 1H), 8.32-8.52 (m, 2H), 8.10-8.29 (m, 2H), 7.79 (s, 1H), 7.68 (br d, J=8.4Hz, 1H), 7.20-7.47(m, 3H), 6.15(br s, 1H), 5.08(br dd, J=5.0, 12.6Hz, 1H), 2.75-3.07 (m, 5H), 2.67-2.67 (m, 1H), 2.53-2.69 (m, 10H), 1.86-2.24 (m, 6H), 1.65-1.76 (m, 2H), 1.61 (s, 6H).

[0256] MS (ESI+) m / z 816.3 [M+H] + .

[0257] Example 10:

[0258] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0259] Intermediate IM-6 (40.2 mg, 122 μmol) was dissolved in 1,2-dichloroethane (1.00 mL) and N,N-dimethylformamide (1.00 mL) at 25°C. Triethylamine (31.0 mg, 306 μmol) was then added, and the reaction mixture was stirred at 25°C for 0.5 hours. Acetic acid (6.13 mg, 102 μmol), sodium triacetoxyborohydride (32.4 mg, 153 μmol), and Intermediate IM-21 (50.0 mg, 102 μmol) were added, and the reaction mixture was stirred at 25°C for 11.5 hours before being concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (column: Phenomenex Luna C18 75*30 mm*3 μm; mobile phase: [H2O(FA)-ACN]; B%: 5%-35%, 8 min) to afford Compound 10 as a white solid (12.0 mg).

[0260] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 10.49-11.50 (m, 1H), 9.54 (s, 1H), 8.36-8.47 (m, 2H), 8.19 (d, J= 8.1Hz, 1H), 7.78 (s, 1H), 7.44-7.58 (m, 1H), 7.41 (s, 1H), 7.01-7.12 (m, 2H), 6.15 (s, 1H), 5.05 (dd, J=5.0 , 13.3Hz, 1H), 4.33 (d, J=17.0Hz, 1H), 4.20 (d, J=16.8Hz, 1H), 3.22-3.32 (m, 8H), 2.84-3.02 (m, 3H), 2.5 3-2.68(m, 6H), 2.28-2.46(m, 2H), 2.04-2.13(m, 2H), 1.93-1.98(m, 2H), 1.63-1.72(m, 2H), 1.60(s, 6H).

[0261] MS (ESI+) m / z 802.3 [M+H] + .

[0262] Example 11:

[0263] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0264] Intermediate IM-2 (50.0 mg, 119 μmol) was dissolved in N,N-dimethylformamide (1.00 mL) and 1,2-dichloroethane (1.00 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (61.0 mg, 476 μmol). The reaction mixture was stirred for 15 minutes, followed by the addition of sodium triacetoxyborohydride (75.8 mg, 357 μmol), glacial acetic acid (7.16 mg, 119 μmol), and Intermediate IM-14 (45.8 mg, 119 μmol). The reaction mixture was stirred at room temperature for 12 hours and then concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (column: Phenomenex luna C18 80*40 mm*3 μm; mobile phase: [H2O(FA)-ACN]; B%: 1%-35%, 8 min) to afford compound 11 as a yellow solid (7.50 mg).

[0265] 1 HNMR (400MHz, DMSO-d6) δ11.08 (br s, 1H), 10.19 (s, 1H), 9.35 (s, 1H), 8.37-8.49 (m, 2H), 8.23 ​​(br d, J=7.5Hz, 1H), 7.57-7.75(m, 2H), 7.19-7.43(m, 2H), 7.07(s, 1H), 5.01-5.15(m, 1H), 3.98(s, 3H ), 3.46-3.49(m, 4H), 2.82-3.03(m, 4H), 2.52-2.71(m, 9H), 1.89-2.32(m, 6H), 1.59-1.73(m, 2H).

[0266] MS (ESI+) m / z 788.3 [M+H] + .

[0267] Example 12:

[0268] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0269] Intermediate IM-21 (39.1 mg, 119 μmol) was dissolved in N,N-dimethylformamide (1.00 mL) and dichloroethane (1.00 mL), followed by the addition of N,N-diisopropylethylamine (70.0 mg, 541 μmol). The reaction mixture was stirred at 25°C for 30 minutes, followed by the addition of sodium acetate borohydride (68.9 mg, 325 μmol), acetic acid (6.51 mg, 108 μmol), and intermediate IM-7 (50.0 mg, 108 μmol). The reaction mixture was stirred at 25°C for 11.5 hours and then concentrated under reduced pressure. The obtained residue was purified by preparative HPLC (chromatographic column: Waters Xbridge BEH C18 100*30mm*10μm; mobile phase: [H2O(10mM NH4HCO3)-ACN]; gradient: 20%-50% B, 8.0min) to give compound 12 as a white solid (8.00mg).

[0270] 1 HNMR (400MHz, DMSO-d6) δ10.93 (br s, 1H), 10.19 (s, 1H), 9.35 (s, 1H), 8.37-8.49 (m, 2H), 8.23 ​​(br d, J=7.8Hz, 1H), 7.64 (s, 1H), 7.52 (d, J=8.6Hz, 1H), 7.07 (s, 2H), 4.98-5.11 (m, 1H), 4.17-4.36 (m, 2H), 3.98 (s, 3H), 3.29 (br d, J=3.6Hz, 6H), 2.84-3.02(m, 4H), 2.56-2.68(m, 8H), 2.33-2.43(m, 1H), 2.08-2.20(m, 2H), 1.89-2.02(m, 3H), 1.58-1.74(m, 2H).

[0271] MS (ESI+) m / z 774.3 [M+H] + .

[0272] Example 13:

[0273] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-3-oxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0274] Intermediate IM-6 (161 mg, 328 μmol) was dissolved in 1,2-dichloroethane (5.00 mL) and N,N-dimethylformamide (5.00 mL) at 25°C, followed by the addition of triethylamine (106 mg, 822 μmol). The reaction mixture was stirred for 0.5 hours, followed by the addition of acetic acid (16.4 mg, 274 μmol), sodium triacetoxyborohydride (87.0 mg, 410 μmol), and intermediate IM-22 (100 mg, 274 μmol). The reaction mixture was stirred at 25°C for 12 hours, then concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (chromatographic column: Phenomenex Gemini NX-C18 (75*30 mm*3 μm); mobile phase: [H2O (0.05% NH3H2O ​​+ 10 mM NH4HCO3)-ACN]; gradient: 20%-50% B, 8.0 min) to give compound 13 as an off-white solid (10.2 mg).

[0275] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 10.97 (br s, 1H), 9.54 (s, 1H), 8.36-8.48 (m, 2H), 8.19 (d, J=7.7Hz, 1H), 7.78 (s, 1H), 7.38-7.46 (m, 2H), 7.21-7.31 (m, 1H), 7.11-7.20 (m, 1H), 6. 15 (s, 1H), 5.10 (dd, J=5.1, 13.3Hz, 1H), 4.33 (d, J=16.8Hz, 1H), 4.20 (d, J=16.8Hz, 1H), 3.11-3.26 (m, 4H), 2.84-3.04 (m, 3H), 2.67 (br d, J=1.5Hz, 1H), 2.58(br s, 4H), 2.50 (br s, 4H), 2.29-2.46 (m, 2H), 2.07-2.20 (m, 2H), 1.88-2.02 (m, 3H), 1.63-1.77 (m, 2H), 1.60 (s, 6H).

[0276] MS (ESI+) m / z 802.3 [M+H] + .

[0277] Example 14:

[0278] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-3-oxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0279] Intermediate IM-22 (39.1 mg, 119 μmol) was dissolved in N,N-dimethylformamide (0.50 mL) and 1,2-dichloroethane (0.5 mL), followed by the addition of N,N-diisopropylethylamine (56.0 mg, 433 μmol), Intermediate IM-7 (50.0 mg, 108 μmol), sodium triacetoxyborohydride (68.9 mg, 325 μmol), and glacial acetic acid (6.51 mg, 108 μmol). The reaction mixture was stirred at 25°C for 12 hours and then concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (column: Phenomenex luna C18 80*40 mm*3 μm; mobile phase: [H2O(FA)-ACN]; gradient: 1%-35% B over 8 min) to afford compound 14 as a yellow solid (8.00 mg).

[0280] 1 HNMR (400MHz, DMSO-d6) δ10.97 (s, 1H), 10.19 (s, 1H), 9.35 (s, 1H), 8.38-8.47 (m, 2H), 8.21-8.26 (m, 1H), 7.65 (s, 1H), 7.43 (d, J=8.5Hz, 1 H), 7.24-7.29 (m, 1H), 7.16 (d, J=2.0Hz, 1H), 7.07 (s, 1H), 5.05-5.13 (m, 1H), 4.30-4.38 (m, 1H), 4.17-4.24 (m, 1H), 3.98 (s, 3H), 3.19 (br s, 4H), 2.85-3.02 (m, 4H), 2.58-2.61 (m, 4H), 2.53 (br s, 4H), 2.32-2.43 (m, 2H), 2.16 (br t, J=10.8Hz, 2H), 1.93-2.01 (m, 3H), 1.62-1.73 (m, 2H).

[0281] MS (ESI+) m / z 774.3 [M+H] + .

[0282] Example 15:

[0283] N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0284] Intermediate IM-1 (173 mg, 387 μmol) was dissolved in N,N-dimethylformamide (1.00 mL) and tetrahydrofuran (1.00 mL) at room temperature, followed by the addition of sodium acetate (47.6 mg, 580 μmol), intermediate IM-15 (150 mg, 387 μmol), sodium acetate borohydride (246 mg, 1.16 mmol), and sodium acetate (69.7 mg, 1.16 mmol). The reaction mixture was stirred at 25°C for 12 hours and then concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (column: Waters Xbridge BEH C18 250*50 mm*10 m; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 25%-55%, 10 min) to afford compound 15 as a yellow solid (11.0 mg).

[0285] 1 HNMR (400MHz, DMSO-d6) δ12.23 (s, 1H), 11.12 (br s, 1H), 9.54 (s, 1H), 8.29-8.53 (m, 2H), 8.18 (br d, J=7.5Hz, 1H), 7.63-7.83(m, 2H), 7.38-7.50(m, 2H), 6.17(s, 1H), 5.00-5.18(m, 1H), 3.60(br d, J=11.2Hz, 2H), 2.81-2.97(m, 5H), 2.52-2.67(m, 3H), 2.19(br d, J=5.4Hz, 2H), 1.92-2.06 (m, 5H), 1.65-1.87 (m, 5H), 1.60 (br s, 6H), 1.25 (br d, J=10.4Hz, 2H).

[0286] MS (ESI+) m / z 819.3 [M+H] + .

[0287] Example 16:

[0288] N-(2-(1-(2-(2-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,7-diazaspiro[3.5]nonan-7-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0289] Compound IM-11 (200 mg, 402 μmol) was dissolved in N,N-dimethylformamide (2.00 mL) and 1,2-dichloroethane (2.00 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (208 mg, 1.61 mmol). After stirring for 15 minutes, intermediate IM-6 (197 mg, 402 μmol), sodium acetate borohydride (256 mg, 1.21 mmol), and acetic acid (24.19 mg, 402 μmol) were added. The reaction mixture was stirred at room temperature for 12 hours and then diluted with water (10 mL). The aqueous phase was extracted with ethyl acetate (10 mL x 3), and the combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (chromatographic column: Waters Xbridge Prep OBD C18 150*40mm*10μm; mobile phase: [H2O(10mMNH4HCO3)-ACN]; gradient: 30%-65% B, 8.0min) to give compound 16 as a yellow solid (18.0mg).

[0290] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.06 (br s, 1H), 9.53 (s, 1H), 8.35-8.48 (m, 2H), 8.19 (d, J=7.8Hz, 1H), 7.78 (s, 1H), 7 .63(d, J=8.3Hz, 1H), 7.41(s, 1H), 6.77(d, J=1.6Hz, 1H), 6.61-6.69(m, 1H), 6.15(s, 1H), 4.99-5.11(m, 1H), 3.74(s, 3H), 2.82-2.59(m, 3H), 2.54-2.68( m, 3H), 2.33-2.46 (m, 8H), 1.90-2.14 (m, 6H), 1.63-1.77 (m, 6H), 1.60 (s, 6H).

[0291] Example 17:

[0292] N-(2-(1-(2-(7-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,7-diazaspiro[3.5]nonan-2-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0293] Compound IM-12 (150 mg, 302 μmol) and DIEA (156 mg, 1.21 mmol) were dissolved in 1,2-dichloroethane (2.00 mL) and N,N-dimethylformamide (2.00 mL) at 25°C. The resulting mixture was stirred for 0.5 hours, and then sodium triacetoxyborohydride (192 mg, 906 μmol), compound IM-6 (158 mg, 302 μmol), and acetic acid (18.1 mg, 302 μmol) were added in sequence. The reaction mixture was stirred at 25°C for 12 hours and then concentrated under reduced pressure. The obtained residue was purified by preparative HPLC (chromatographic column: Phenomenex Gemini NX-C18 (75*30mm*3μm); mobile phase: [H2O0.05% NH3H2O+10mM NH4HCO3)-ACN]; gradient: 20%-40% B, 8.0min) to obtain compound 17 as an off-white solid (6.00mg).

[0294] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 9.54 (s, 1H), 8.33-8.52 (m, 2H), 8.25 (s, 1H), 8.1 9 (d, J=7.6Hz, 1H), 7.78 (s, 1H), 7.65 (d, J=8.6Hz, 1H), 7.40 (s, 1H), 7.32 (s, 1H), 7.24 (br d, J=8.8H z, 1H), 5.93-6.34 (m, 1H), 5.06 (dd, J=5.4, 12.9Hz, 1H), 3.44 (br s, 5H), 3.13 (s, 4H), 2.84-2.98 (m, 3H), 2.53-2.72 (m, 5H), 2.34 (br t, J=6.2Hz, 2H), 2.10 (br t, J=10.9Hz, 2H), 1.91-2.03 (m, 3H), 1.76 (br s, 4H), 1.67 (br d, J=10.4Hz, 1H), 1.60 (s, 6H).

[0295] Example 18:

[0296] N-(2-(1-(2-(1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0297] Compound IM-1 (200 mg, 413 μmol) was dissolved in dichloroethane (2.00 mL) and N,N-dimethylformamide (2.00 mL), followed by the addition of N,N-diisopropylethylamine (213 mg, 1.65 mmol). After stirring for 5 minutes, intermediate IM-16 (290 mg, 454 μmol), sodium acetate borohydride (262 mg, 1.24 mmol), and acetic acid (24.8 mg, 413 μmol) were added. The reaction mixture was stirred at 25°C for 12 hours and then concentrated to dryness under reduced pressure. The resulting residue was purified by high performance liquid chromatography (formic acid system) to obtain compound 18 as a yellow solid (21.0 mg).

[0298] 1 HNMR (400MHz, DMSO-d6) δ12.22(s, 1H), 11.07(s, 1H), 9.54(s, 1H), 8.32-8.50(m, 2H), 8.17-8.19(m, 1H), 7.78(s, 1H), 7.65(d, J=8.5Hz, 1H), 7.41(s, 1H), 7.30(s, 1H), 7.21-7.25(m, 1H), 6.14(s, 1H), 4.98-5.13(m, 1H), 4.04(br d, J=12.8Hz, 2H), 2.82-3.00 (m, 5H), 2.55-2.68 (m, 3H), 2.32-2.44 (m, 2H), 1.93-2 .12(m, 5H), 1.62-1.82(m, 5H), 1.60(s, 6H), 1.38-1.48(m, 2H), 1.13-1.26(m, 2H).

[0299] MS (ESI+) m / z 815.3 [M+H] + .

[0300] Example 19:

[0301] N-(2-(1-(3-(4-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)propyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0302] Intermediate IM-1 (85.0 mg, 189 μmol) was dissolved in N,N-dimethylformamide (3.00 mL) at room temperature, followed by the addition of N,N-diisopropylethylamine (73.6 mg, 569 μmol), sodium iodide (85.43 mg, 569 μmol), and intermediate IM-17 (200 mg, 208 μmol). The reaction mixture was heated to 80°C and stirred for 12 hours, then concentrated under reduced pressure. The resulting residue was purified by high performance liquid chromatography (ammonium bicarbonate system) to yield compound 19 (15.0 mg).

[0303] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.07 (br s, 1H), 9.54 (s, 1H), 8.35-8.48 (m, 2H), 8.19 (d, J=7.7Hz, 1H), 7.62-7.85 (m, 2H), 7.24-7.43 (m, 3H), 6.13 (s, 1H), 4.99-5.15 (m, 1H), 3.44 (br s, 4H), 2.83-2.95 (m, 3H), 2.52-2.69 (m, 6H), 2.31-2.38 (m, 4H), 1.94-2.05 (m, 5H), 1.62-1.74 (m, 5H), 1.60 (s, 6H).

[0304] MS (ESI+) m / z 830.4 [M+H] + .

[0305] Example 20:

[0306] N-(2-(1-(1-(1-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)azetidin-3-yl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0307] Intermediate IM-8 (100 mg, 185 μmol) was dissolved in N,N-dimethylformamide (2.00 mL) and tetrahydrofuran (2.00 mL), and sodium acetate (30.4 mg, 371 μmol) was added. After stirring for 15 minutes, sodium triacetoxyborohydride (117 mg, 556 μmol), intermediate IM-18 (82.4 mg, 185 μmol) and acetic acid (33.4 mg, 556 μmol) were added. The reaction mixture was stirred at 25 ° C for 12 hours, then filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by high performance liquid chromatography (ammonium bicarbonate system) to obtain compound 20 as a yellow solid (25 mg).

[0308] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.07 (s, 1H), 9.54 (s, 1H), 8.34-8.52 (m, 2H), 8.19 (d, J=7. 7Hz, 1H), 7.78 (s, 1H), 7.65 (d, J=8.6Hz, 1H), 7.40 (s, 1H), 7.31 (s, 1H), 7.19-7.26 (m, 1H), 6.14 (s, 1H), 5.00-5.12(m, 1H), 3.79-3.88(m, 2H), 3.40(brt, J=4.8Hz, 2H), 3.07-3.18(m, 2H), 2.75-2.94(m, 6H), 2 .54-2.68(m, 3H), 2.25-2.33(m, 1H), 1.82-2.07(m, 6H), 1.64-1.73(m, 3H), 1.60(s, 6H), 1.18-1.27(m, 2H).

[0309] MS (ESI+) m / z 842.4 [M+H] + .

[0310] Example 21:

[0311] N-(2-(1-(2-(6-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-2,6-diazaspiro[3.3]heptan-2-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0312] Intermediate IM-19 (100 mg, 282 μmol) and N,N-diisopropylethylamine (100 mg, 282 μmol) were dissolved in 1,2-dichloroethane (2.00 mL) and N,N-dimethylformamide (2.00 mL) at 25°C. After stirring for 0.5 hours, sodium triacetoxyborohydride (179 mg, 846 μmol), compound IM-6 (100 mg, 282 μmol), and acetic acid (16.9 mg, 282 μmol) were added in sequence. The reaction mixture was stirred at 25°C for 12 hours and then concentrated under reduced pressure. The obtained residue was purified by preparative HPLC (chromatographic column: Waters Xbridge BEH C18 100*30mm*10μm; mobile phase: [H2O(10mM NH4HCO3)-ACN]; gradient: 20%-65% B, 8.0min), and the obtained crude product was purified again by preparative HPLC (chromatographic column: Phenomenex luna C18 100*40mm*5μm; mobile phase: [H2O(0.2%FA)-ACN]; gradient: 5%-45% B, 8.0min) to obtain compound 21 as a white solid (10.4mg).

[0313] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.06 (s, 1H), 9.53 (s, 1H), 8.36-8.47 (m, 2H), 8 .16-8.24(m, 1H), 7.77(s, 1H), 7.64(d, J=8.2Hz, 1H), 7.40(s, 1H), 6.79(s, 1H), 6.65(br d, J=8.2Hz, 1H), 6.13 (s, 1H), 5.05 (dd, J=5.4, 12.7Hz, 1H), 4.10 (s, 4H), 3.33-3.34 (m, 4H), 2.82-2. 97(m, 3H), 2.52-2.69(m, 5H), 2.27-2.35(m, 2H), 1.89-2.11(m, 5H), 1.62-1.74(m, 2H), 1.60(s, 6H).

[0314] MS (ESI+) m / z 828.4 [M+H] + .

[0315] Example 22:

[0316] N-(2-(1-(2-(4-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperazin-1-yl)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0317] Intermediate IM-20 (100 mg, 207 μmol) and intermediate IM-1 (92.7 mg, 207 μmol) were dissolved in dimethylformamide (2.00 mL) at 25°C, followed by the addition of N,N-diisopropylethylamine (80.3 mg, 621 μmol) and sodium iodide (93.2 mg, 621 μmol). The reaction mixture was stirred at 80°C for 12 hours and then concentrated under reduced pressure. The resulting residue was purified by high performance liquid chromatography (ammonium bicarbonate system) to yield compound 22 as a yellow solid (5.30 mg).

[0318] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.11 (br s, 1H), 9.53 (s, 1H), 8.32-8.50 (m, 2H), 8.13-8.28 (m, 1H), 7.69-7.82 (m, 2H), 7.38-7.48 (m, 2H), 6.15 (br s, 1H), 5.03-5.17 (m, 1H), 3.25 (br s, 6H), 2.81-3.04 (m, 4H), 2.55-2.70 (m, 7H), 1.90 (br s, 6H), 1.64-1.74 (m, 2H), 1.60 (s, 6H).

[0319] MS (ESI+) m / z 834.3 [M+H] + .

[0320] Example 23:

[0321] N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1-oxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0322] Intermediate IM-1 (155 mg, 321 μmol) was dissolved in N,N-dimethylformamide (2.00 mL) and tetrahydrofuran (2.00 mL) at room temperature, followed by the addition of sodium acetate (79 mg, 964 μmol). The mixture was stirred for 15 minutes, followed by the addition of Intermediate IM-23 (150 mg, 321 μmol), sodium acetate (102 mg, 482 μmol), and acetic acid (57.9 mg, 964 μmol). The reaction mixture was stirred at 25°C for 12 hours and then concentrated to dryness under reduced pressure. The resulting residue was purified by HPLC (column: Waters Xbridge BEH C18 250*50 mm*10 μm; mobile phase: [H2O(NH4HCO3)-ACN]; B%: 25%-55%, 10 min) to afford compound 23 as a white solid (20.0 mg).

[0323] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 10.96 (br s, 1H), 9.54 (s, 1H), 8.43-8.49 (m, 1H), 8.36-8.41 (m, 1H), 8.16-8.23 (m, 1H), 7.78 (s, 1H), 7.37-7.43 (m, 2H), 7.23 (br d, J=7.6Hz, 1H), 6.14 (s, 1H), 5.02-5.11 (m, 1H), 4.32-4.40 (m, 1H), 4.20-4.28 (m, 1H), 3.48 (br d, J=2.1Hz, 2H), 2.86-2.96(m, 3H), 2.73-2.79(m, 2H), 2.61-2.68(m, 2H), 2.32-2.40(m, 1H), 2.22(br d, J=7.0Hz, 2H), 1.94-2.07 (m, 5H), 1.83 (br d, J=11.6Hz, 2H), 1.75-1.66 (m, 3H), 1.60 (s, 6H), 1.35-1.24 (m, 2H).

[0324] MS (ESI+) m / z 805.4 [M+H] + .

[0325] Example 24:

[0326] N-(2-(1-((3-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-5-yl)-3-azabicyclo[3.1.0]hexan-6-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0327] Intermediate IM-1 (131 mg, 272 μmol) was dissolved in N,N-dimethylformamide (0.50 mL) and tetrahydrofuran (0.50 mL). Sodium acetate (33.5 mg, 0.406 mmol) was added, and the mixture was stirred at 25°C for 0.5 hours. Sodium triacetoxyborohydride (173 mg, 0.816 mmol), Intermediate IM-24 (100 mg, 272 μmol), and acetic acid (49.0 mg, 0.816 mmol) were added sequentially, and the resulting reaction mixture was stirred at 25°C for 12 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by preparative HPLC (column: Waters Xbridge Prep OBD C18 150*40 mm*10 μm; mobile phase: [H2O(10 mMNH4HCO3)-ACN]; gradient: 30%-70% B over 8.0 min) to afford compound 24 as a yellow solid (11.0 mg).

[0328] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.06 (br s, 1H), 9.54 (s, 1H), 8.36-8.48 (m, 2H), 8.19 (d, J=7.7Hz, 1H), 7.79 (s, 1H), 7.63 (d, J=8.4Hz, 1H), 7.41 (s, 1H), 6.92 (s, 1H), 6.83 (br d, J=8.7Hz, 1H), 6.14 (s, 1H), 5.05 (dd, J=5.4, 13.0Hz, 1H), 3.68 (br d, J=10.3Hz, 2H), 3.42-3.50 (m, 2H), 3.02 (br d, J=10.9Hz, 2H), 2.81-2.94(m, 1H), 2.58-2.68(m, 2H), 2.54-2.58(m, 1H), 2.32(br d, J=6.0Hz, 2H), 2.10(br t, J=10.5Hz, 2H), 1.93-2.04 (m, 3H), 1.62-1.72 (m, 4H), 1.60 (s, 6H), 0.49-1.05 (m, 1H).

[0329] MS (ESI+) m / z 799.4 [M+H] + .

[0330] Example 25:

[0331] (R)-N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0332] Step 1: Preparation of (R)-tert-butyl 5-amino-4-(5,6-difluoro-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-25a)

[0333] 5,6-Difluoroisobenzofuran-1,3-dione (5.00 g, 27.1 mmol) and (R)-tert-butyl 4,5-diamino-5-oxopentanoate (6.59 g, 32.5 mmol) were dissolved in toluene (50.0 mL). Triethylamine (8.24 g, 81.4 mmol) was added to the reaction system at 25°C. After the addition, the resulting reaction mixture was heated to 80°C and stirred for 12 hours. The reaction mixture was quenched by the addition of 50 mL of water at 25°C and then extracted with ethyl acetate (50 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain intermediate IM-25a as a white solid (5.00 g).

[0334] MS (ESI+) m / z 313.2 [M-55] + .

[0335] Step 2: Preparation of (R)-tert-butyl 5-amino-4-(5-(4-(dimethoxymethyl)piperidin-1-yl)-6-fluoro-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-25b)

[0336] Intermediate IM-25a (2.00 g, 5.43 mmol) and 4-(dimethoxymethyl)piperidine (1.04 g, 6.52 mmol) were dissolved in dimethyl sulfoxide (20.0 mL), and N,N-diisopropylethylamine (1.40 g, 10.8 mmol) was added at 25°C. The resulting reaction mixture was stirred at 90°C for 15 hours. 20 mL of water was added at 25°C to quench the reaction, followed by extraction with ethyl acetate (30 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain intermediate IM-25b as a yellow solid (2.30 g).

[0337] MS (ESI+) m / z 508.2 [M+H] + .

[0338] Step 3: Preparation of (R)-tert-butyl 5-amino-4-(5-fluoro-6-(4-formylpiperidin-1-yl)-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-25c)

[0339] Intermediate IM-25b (1.00 g, 1.97 mmol) was dissolved in tetrahydrofuran (10.0 mL) and water (2.00 mL). Pyridinium p-toluenesulfonate (1.49 g, 5.91 mmol) was added to the reaction system under nitrogen at 25°C. The reaction was heated to 70°C and stirred at 70°C for 12 hours. The reaction mixture was concentrated under reduced pressure to afford intermediate IM-25c as a yellow solid (700 mg, crude), which was used directly without further purification.

[0340] MS (ESI+) m / z 406.3 [M-55].

[0341] Step 4: Preparation of (R)-tert-butyl 5-amino-4-(5-fluoro-6-(4-((4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)methyl)piperidin-1-yl)-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-25d)

[0342] Intermediate IM-1 (678 mg, 1.52 mmol) was dissolved in N,N-dimethylformamide (7.00 mL) and tetrahydrofuran (7.00 mL). Anhydrous sodium acetate (248 mg, 3.03 mmol) was added to the reaction system at 25°C and the reaction was stirred at 25°C for 30 minutes. Intermediate IM-25c (700 mg, 1.52 mmol), sodium triacetoxyborohydride (964 mg, 4.55 mmol) and glacial acetic acid (273 mg, 4.55 mmol) were then added to the reaction system. The reaction mixture was stirred at 25°C for 3.5 hours, then filtered and concentrated under reduced pressure to give intermediate IM-25d as a yellow solid (1.20 g, crude product).

[0343] MS (ESI+) m / z 893.6 [M+H] + .

[0344] Step 5: Preparation of (R)-N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (25)

[0345] Intermediate IM-25d (100 mg, 111.99 μmol) was dissolved in acetonitrile (1.00 mL). Anhydrous benzenesulfonic acid (35.4 mg, 223 μmol) was added to the reaction system at 25°C. The reaction was heated to 80°C and stirred at 80°C for 12 hours. The mixture was filtered and concentrated under reduced pressure to obtain a residue. The residue was purified by pre-HPLC (column: Phenomenex luna C18 100*40 mm*5 μm; mobile phase: [H2O (0.2% FA)-ACN]; gradient: 1%-40% B over 8.0 min) to obtain compound 25 as a yellow solid (12.0 mg).

[0346] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.10 (br s, 1H), 9.54 (s, 1H), 8.34-8.49 (m, 2H), 8.18 (s, 1H), 7.79 (s, 1H), 7.70 (d, J=11.4Hz, 1H), 7.37-7.47 (m, 2H), 6.15 (br s, 1H), 5.10 (dd, J=5.4, 12.8Hz, 1H), 3.62 (br d, J=12.0Hz, 2H), 2.83-2.96 (m, 5H), 2.54-2.72 (m, 3H), 2.23 (br d, J=6.6Hz, 2H), 1.93-2.11(m, 5H), 1.65-1.90(m, 5H), 1.60(s, 6H), 1.20-1.35(m, 2H).

[0347] MS (ESI+) m / z 819.4 [M+H] + .

[0348] Example 26:

[0349] (S)-N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0350] Step 1: Preparation of (S)-tert-butyl 5-amino-4-(5,6-difluoro-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-26a)

[0351] 5,6-Difluoroisobenzofuran-1,3-dione (10.0 g, 54.3 mmol) and (S)-tert-butyl 4,5-diamino-5-oxopentanoate (15.5 g, 65.1 mmol) were dissolved in toluene (50.0 mL). Triethylamine (16.4 g, 162 mmol) was added to the reaction system at 25°C. After complete addition, the resulting mixture was heated to 80°C and stirred for 12 hours. The reaction mixture was quenched by addition of water (30 mL) at 25°C and then extracted with ethyl acetate (40 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to obtain intermediate IM-26a as a white solid (1.50 g).

[0352] MS (ESI+) m / z 313.2 [M-55].

[0353] Step 2: Preparation of (S)-tert-butyl 5-amino-4-(5-(4-(dimethoxymethyl)piperidin-1-yl)-6-fluoro-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-26b)

[0354] Intermediate IM-26a (1.50 g, 4.07 mmol) and 4-(dimethoxymethyl)piperidine (778 mg, 4.89 mmol) were dissolved in dimethyl sulfoxide (15.0 mL), and N,N-diisopropylethylamine (1.05 g, 8.14 mmol) was added at 25°C. The reaction mixture was stirred at 90°C for 15 hours. 20 mL of water was added at 25°C to quench the reaction, followed by extraction with ethyl acetate (30 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 0 / 1) to afford Intermediate IM-26b as a yellow solid (1.50 g, 2.96 mmol).

[0355] MS (ESI+) m / z 508.2 [M+H] + .

[0356] Step 3: Preparation of (S)-tert-butyl 5-amino-4-(5-fluoro-6-(4-formylpiperidin-1-yl)-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-26c)

[0357] Intermediate IM-26b (700 mg, 1.38 mmol) was dissolved in tetrahydrofuran (5.00 mL) and water (1.00 mL). Pyridinium p-toluenesulfonate (1.04 g, 4.14 mmol) was added at 25°C under nitrogen. The reaction was warmed to 70°C and stirred at 70°C for 12 hours. The mixture was concentrated under reduced pressure to give intermediate IM-26c as a yellow solid (600 mg, crude product), which was used directly without further purification.

[0358] MS (ESI+) m / z 462.2 [M+H] + .

[0359] Step 4: Preparation of (s)-tert-butyl 5-amino-4-(5-fluoro-6-(4-((4-(7-(2-hydroxypropan-2-yl)-6-(6-(trifluoromethyl)pyridine-2-carboxamido)imidazo[1,2-a]pyridin-2-yl)piperidin-1-yl)methyl)piperidin-1-yl)-1,3-dioxoisoindolin-2-yl)-5-oxopentanoate (IM-26d)

[0360] Intermediate IM-1 (484 mg, 1.08 mmol) was dissolved in N,N-dimethylformamide (5.00 mL) and tetrahydrofuran (5.00 mL). Anhydrous sodium acetate (266 mg, 3.25 mmol) was added at 25°C and the reaction was stirred at 25°C for 30 minutes. Intermediate IM-26c (500 mg, 1.08 mmol), sodium triacetoxyborohydride (688 mg, 3.25 mmol) and glacial acetic acid (65.0 mg, 1.08 mmol) were then added to the reaction mixture. The reaction mixture was stirred at 25°C for 3.5 hours, then filtered and concentrated under reduced pressure to give intermediate IM-26d as a yellow solid (500 mg, crude product).

[0361] MS (ESI+) 893.3 [M+H] + .

[0362] Step 5: Preparation of (S)-N-(2-(1-((1-(2-(2,6-dioxopiperidin-3-yl)-6-fluoro-1,3-dioxoisoindolin-5-yl)piperidin-4-yl)methyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (26)

[0363] Compound IM-26d (50.0 mg, 56.0 μmol) was dissolved in acetonitrile (1.00 mL). Anhydrous benzenesulfonic acid (17.7 mg, 111 μmol) was added to the reaction system at 25°C. The reaction was heated to 80°C and stirred at 80°C for 12 hours. The mixture was filtered and then concentrated under reduced pressure. The resulting residue was purified by HPLC (column: Phenomenex luna C18 100*40 mm*5 μm; mobile phase: [H2O (0.2% FA)-ACN]; gradient: 10%-50% B over 8.0 min) to yield compound 26 as a yellow solid (11.0 mg).

[0364] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.10 (br s, 1H), 9.54 (s, 1H), 8.31-8.51 (m, 2H), 8.09-8.25 (m, 1H), 7.63-7.86 (m, 2H), 7.35-7.51 (m, 2H), 6.15 (s, 1H), 5.10 (br dd, J=4.7, 12.3Hz, 1H), 2.81-3.06 (m, 6H), 2.67 (br s, 2H), 2.31 (br d, J=17.3Hz, 3H), 2.00 (br d, J=9.4Hz, 4H), 1.69-1.89 (m, 5H), 1.60 (br s, 6H), 1.19-1.35 (m, 4H)

[0365] MS (ESI+) m / z 819.3 [M+H] + .

[0366] Comparative Example 1:

[0367] N-(2-(1-(2-(2-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)ethoxy)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0368] Step 1: Preparation of 2-(2,6-dioxopiperidin-3-yl)-4-((2-(2-hydroxyethoxy)ethyl)amino)isoindoline-1,3-dione (IM-25a)

[0369] 2-(2,6-dioxopiperidin-3-yl)-4-fluoroisoindoline-1,3-dione (5.00 g, 26.8 mmol) and 2-(2-aminoethoxy)ethanol (2.82 g, 26.8 mmol) were dissolved in dimethyl sulfoxide (10.0 mL), followed by the addition of N,N-diisopropylethylamine (3.47 g, 26.8 mmol). The resulting reaction mixture was heated to 70°C and stirred for 12 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to afford Intermediate IM-27a as a yellow oil (7.70 g).

[0370] 1 HNMR(400MHz, DMSO-d6)δ 11.05 (s, 1H), 7.55 (dd, J=7.3, 8.3Hz, 1H), 7.11 (d, J=8.6Hz, 1H), 7.00 (d, J=7.0Hz, 1H), 6.57 (t, J=5.7Hz, 1H), 5.02 (dd, J=5.4 , 12.9Hz, 1H), 4.56 (t, J=5.2Hz, 1H), 3.53-3.65 (m, 2H), 3.39-3.51 (m, 6H), 2.77-3.02 (m, 1H), 2.67 (s, 1H), 2.60-2.55 (m, 2H).

[0371] Step 2: Preparation of 2-(2-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)ethoxy)ethyl methanesulfonate (IM-27b)

[0372] Intermediate IM-27a (1.00 g, 2.77 mmol) was dissolved in dichloromethane (10 mL), and triethylamine (1.12 g, 11.0 mmol) and methanesulfonic anhydride (2.23 g, 19.4 mmol) were added at 0°C. The resulting reaction mixture was stirred at 25°C for 3 hours. Water (20 mL) was added at 0°C to quench the reaction mixture, followed by extraction with dichloromethane (30.0 mL x 3). The combined organic layers were washed with sodium chloride (10.0 mL x 3), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to afford intermediate IM-27b as a yellow solid (500 mg).

[0373] 1HNMR: (400MHz, DMSO-d6) δ11.10 (s, 1H), 7.59 (dd, J=7.2, 8.4Hz, 1H), 7.16 (d, J=8.6Hz, 1H), 7.05 (d, J=7.0Hz, 1H), 6.63 (brt, J=5.9Hz, 1H), 5.0 5 (dd, J=5.4, 12.8Hz, 1H), 4.31 (dd, J=3.5, 5.3Hz, 2H), 3.61-3.77 (m, 4H ), 3.45-3.55(m, 3H), 3.16(s, 3H), 2.82-2.94(m, 1H), 2.52-2.63(m, 2H).

[0374] Step 3: Preparation of N-(2-(1-(2-(2-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)ethoxy)ethyl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (Comparative Example 1)

[0375] Intermediate IM-27b (162 mg, 368 μmol) and IM-1 (150 mg, 335 μmol) were dissolved in N,N-dimethylformamide (2.00 mL), and N,N-diisopropylethylamine (129 mg, 1.01 mmol) and sodium iodide (100 mg, 670 μmol) were added sequentially. The resulting mixture was heated to 80°C and stirred for 4 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by preparative HPLC (column: Phenomenex luna C18 80*40 mm*3 μm; mobile phase: [H2O(FA)-ACN]; B%: 5%-45%, 8 min) to obtain Comparative Example 1 as a yellow solid (27.0 mg).

[0376] 1HNMR (400MHz, DMSO-d6) δ12.23 (s, 1H), 11.21 (br s, 1H), 9.54 (s, 1H), 8.36-8.47 (m, 2H), 8.18-8.20 (m, 1H), 7.74 (s, 1H), 7.56-7.62 (m, 1H), 7.42 (s, 1H), 7.17 (d, J = 8.7Hz, 1H), 7.05 (d, J = 7.1Hz, 1H), 6.62(br t, J=5.6Hz, 1H), 6.15 (s, 1H), 5.05 (dd, J=5.4, 12.4Hz, 1H), 3.56-3.64 (m, 4H), 3.44-3.52 (m, 3H), 2.74-3.00 (m, 4H), 2.52-2.68 (m, 5H), 2.12 (br t, J=11.3Hz, 2H), 1.85-2.03 (m, 3H), 1.60 (s, 6H).

[0377] MS (ESI+) m / z 791.4 [M+H] + .

[0378] Comparative Example 2:

[0379] N-(2-(1-(6-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-4-yl)hex-5-yn-1-yl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide

[0380] Step 1: Preparation of 3-(4-(6-hydroxyhex-1-yn-1-yl)-1-oxoisoindolin-2-yl)piperidine-2,6-dione (IM-28a)

[0381] 3-(4-Bromo-1-oxoisoindolin-2-yl)piperidine-2,6-dione (1.00 g, 3.09 mmol) and 5-hexyn-1-ol (607 mg, 6.19 mmol) were dissolved in dimethylformamide (20.0 mL). Cuprous iodide (353 mg, 1.86 mmol), dichlorobis(triphenylphosphine)palladium(II) (217 mg, 309 μmol), and triethylamine (7.27 g, 71.8 mmol) were added sequentially at 25°C. The reaction mixture was heated to 60°C and stirred for 12 hours. The reaction mixture was diluted with water (20 mL) and extracted with ethyl acetate (20 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to afford Intermediate IM-28a as a yellow solid (200 mg).

[0382] 1 HNMR (400MHz, DMSO-d6) δ11.00 (s, 1H), 7.70 (d, J=7.3Hz, 1H), 7.63 (br d, J=7.5Hz, 1H), 7.53 (br d, J=7.6Hz, 1H), 5.09-5.19(m, 1H), 4.41-4.48(m, 2H), 4.27-4.34(m, 1H), 3.41-3.48(m, 4H), 2.88-2.98(m, 1H), 2.59(br d, J=17.7Hz, 2H), 1.97-2.07(m, 1H), 1.53-1.63(m, 4H).

[0383] Step 2: Preparation of 6-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-4-yl)hex-5-yn-1-yl methanesulfonate (IM-28b)

[0384] Intermediate IM-28a (200 mg, 587 μmol) was dissolved in tetrahydrofuran (1.00 mL) at room temperature, and triethylamine (148 mg, 1.47 mmol) and methanesulfonic anhydride (178 mg, 881 μmol) were added. The resulting reaction mixture was then stirred at room temperature for 12 hours. The reaction mixture was diluted with water (10 mL) and extracted with ethyl acetate (10 mL x 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, petroleum ether / ethyl acetate volume ratio = 100 / 1 to 10 / 1) to obtain intermediate IM-28b as a white solid (200 mg).

[0385] Step 3: Preparation of N-(2-(1-(6-(2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-4-yl)hex-5-yn-1-yl)piperidin-4-yl)-7-(2-hydroxypropan-2-yl)imidazo[1,2-a]pyridin-6-yl)-6-(trifluoromethyl)pyridine-2-carboxamide (Comparative Example 2)

[0386] Intermediate IM-28b (110 mg, 210 μmol) was dissolved in acetonitrile (2.00 mL), and sodium bicarbonate (35.3 mg, 420 μmol) and intermediate IM-1 (94.1 mg, 210 μmol) were added at room temperature. The reaction mixture was then heated to 80°C and stirred for 12 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by preparative HPLC (column: Phenomenex luna C18 80*40 mm*3 μm; mobile phase: [H2O(FA)-ACN]; B%: 10%-50%, 8 min) to afford the compound of Comparative Example 2 as a white solid (16.1 mg).

[0387] 1 HNMR (400MHz, DMSO-d6) δ12.22 (s, 1H), 11.04 (br s, 1H), 9.54 (s, 1H), 8.43-8.47 (m, 1H), 8.35-8.41 (m, 1H), 8.17-8.23 (m, 2H), 7.78 (s, 1H), 7. 71 (d, J=7.5Hz, 1H), 7.64 (d, J=7.5Hz, 1H), 7.50-7.55 (m, 1H), 7.41 (s, 1H), 5.11-5.18 (m, 1H) , 4.44-4.50(m, 1H), 4.29-4.35(m, 1H), 2.84-3.12(m, 4H), 2.60-2.79(m, 2H), 2.53-2.60(m, 2 H), 2.38-2.48(m, 3H), 2.11-2.33(m, 3H), 1.96-2.05(m, 3H), 1.65-1.78(m, 4H), 1.60(s, 6H).

[0388] MS (ESI+) m / z 770.3 [M+H] + .

[0389] The compounds prepared in the Examples and Comparative Examples were subjected to an IRAK4 protein degradation experiment, and the experimental process was as follows:

[0390] HiBiT-based THP1-HIBiT-IRAK4 intracellular degradation experiment

[0391] THP1-HIBiT-IRAK4 cells were cultured in RPMI1640 medium supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin (PS) at 37°C, 5% CO2. THP1-HIBiT-IRAK4 cells were seeded at 5,000 cells / 40 μL / well in a 384-well plate. Compound solutions of varying concentrations were added to the wells at 40 nL / well and incubated at 37°C, 5% CO2 for 24 hours. HiBit lysis detection reagent was added to the wells, the plates were incubated at room temperature for 30 minutes, and the luminescence values ​​were read on an Envision.

[0392] Degradation rate (%) = (luminescence value of compound wells / average luminescence value of DMSO wells) × 100

[0393] XLFIT software was used to obtain the DC of the compound using the following nonlinear fitting formula: 50 (half-maximal degradation concentration):

[0394] Y=Bottom+(Top-Bottom) / (1+10^((LogDC 50 -X)×Hill slope)

[0395] X: log value of compound concentration;

[0396] Y: degradation rate

[0397] IRAK4 protein degradation in DCs 50 The results are shown in Table 1. The experimental results showed that the compounds of the examples had significant degradation activity on IRAK4 protein, while the compounds of the comparative examples had no IRAK4 protein degradation activity (DC50>10000 nM).

[0398] Table 1

[0399] Assay of IRAK4 degradation by Western blotting

[0400] (1) Compound treatment and lysate preparation

[0401] a) On day 1, OCI-LY10 cells were plated at 1.5×10 6 10 cells / mL / well were seeded into a 12-well plate, and then the test compound was diluted with DMSO, and 1 μL of the diluted compound solution was added to the cell supernatant, and the plate was incubated in a 37°C, 5% CO2 incubator overnight.

[0402] b) On day 2, cells were harvested and transferred to a 1.5 mL centrifuge tube and centrifuged at 3000 rpm for 5 minutes.

[0403] c) Wash cells once with ice-cold PBS and centrifuge at 3000 rpm for 5 minutes at 4°C.

[0404] d) Add one protease inhibitor tablet and one phosphatase inhibitor tablet to 20 mL of cell lysis buffer and mix gently until completely dissolved. Add 50 μL of the prepared cell lysis buffer to a centrifuge tube and lyse the cells on ice for 30 minutes.

[0405] e) Centrifuge at 13,000 rpm at 4°C for 15 minutes.

[0406] f) Transfer the supernatant to a new tube and determine the protein concentration using a BCA kit

[0407] (2) Western blotting

[0408] a) Add 20 μg / well of sample to 4-12% BTMidi protein gel (1 mm, 26 wells) and run at a constant voltage of 120 V for 5 minutes and at a constant voltage of 150 V for 55 minutes.

[0409] b) The samples were transferred to PVDF membrane using a Bio-Rad wet transfer apparatus at 300 mA for 90 minutes.

[0410] c) Block the membrane with 1xTBS-T containing 5% BSA for 1 hour at room temperature.

[0411] d) The membrane was incubated with the corresponding primary antibody solution (rabbit anti-IRAK4 and mouse anti-GAPDH) at 4°C overnight.

[0412] e) The membrane was washed 3×5 minutes with 1×TBST, and incubated with a secondary antibody solution (HRP-labeled anti-mouse antibody and HRP-labeled anti-rabbit antibody) at room temperature for 90 minutes.

[0413] f) Wash the membrane 3 x 5 min with 1 x TBST.

[0414] g) Enhanced chemiluminescence (ECL) substrate was added and scanned using the IBright CL1500 imaging system.

[0415] The experimental results are shown in Figures 1-26, and the corresponding relationships between Figures 1-26 and the compounds are listed in Table 2. In the figures, "rabbit anti-IRAK4" indicates that IRAK4 protein was detected using a rabbit anti-IRAK4 antibody as the primary antibody, and "mouse anti-GAPDH" indicates that GAPDH was detected using a mouse anti-GAPDH antibody as the primary antibody. The results demonstrate that all of the compounds in the examples exhibited significant IRAK4 protein degradation activity at concentrations of 100 nM and 1000 nM.

[0416] Table 2

[0417] Liver microsome stability assay

[0418] (1) Materials

[0419] Microsomes were stored at −80°C and thawed in a 37°C water bath before use. All other reagents were purchased from local suppliers.

[0420] (2) Experimental design

[0421] Step 1: Configure the reaction system as follows

[0422] Step 2: Add 40 μL of 10 mM NADPH solution and 40 μL of 20 mM UDPGA solution to the above reaction system, for final concentrations of 1 mM NADPH and 2 mM UDPGA, respectively. Replace the NADPH and UDPGA solutions with 80 μL of ultrapure water as a negative control. Preincubate the reaction system in a 37°C water bath for 10 minutes.

[0423] Step 3: Initiate the reaction by adding 4 μL of 100 μM test compound and control drugs (verapamil and 7-OH coumarin) to the reaction mixture. The final concentration of the drug is 1 μM.

[0424] Step 4: Remove 50 μL of the reaction sample at 0, 15, 30, 45, and 60 minutes and quench with 4x the volume of cold acetonitrile containing internal standards (100 nM alprazolam, 200 nM labetalol, 2 μM ketoprofen, and 200 nM caffeine). Centrifuge the sample at 3220 g for 40 minutes. After centrifugation, remove 100 μL of the supernatant and mix with 100 μL of ultrapure water for LC-MS / MS analysis.

[0425] (3) Data Analysis

[0426] All data calculations were performed using Microsoft Excel software. Peak areas were determined from extracted ion chromatograms and used to calculate the residual percentage at each time point.

[0427] The remaining percentage is calculated using the following formula: Remaining percentage (%) = (peak area ratio 时间点 / peak area ratio 0分钟 )×100

[0428] The elimination rate constant (k) was determined by linear fitting the natural logarithm of the percentage of parent drug remaining versus time.

[0429] The half-life (t1 / 2) is calculated by the elimination rate constant: t1 / 2 = 0.693 / k

[0430] In vitro intrinsic clearance (unit: μL / min / mg) was calculated using the following formula: invitroCLint = kV / N

[0431] Where: V = incubation volume per well (0.4 mL); N = microsomal content per well (0.2 mg)

[0432] The experimental results are shown in Table 3. Example 15 has good metabolic stability in liver microsome metabolism of different species.

[0433] Table 3

[0434] In vivo pharmacokinetic studies

[0435] The following experimental protocol was used to study the pharmacokinetic behavior of Example 1 and Example 15 in mice and evaluate their pharmacokinetic characteristics.

[0436] Experimental plan:

[0437] Three healthy male CD1 mice weighing 20-25 g were intravenously injected with 2 mg / kg of the compound in a volume of 10 mL / kg prepared with 5% DMSO / 15% Solutol% / 80% PBS (w / v). They had free access to water and food before the experiment.

[0438] Three healthy male CD1 mice weighing 20-25 g were orally administered with 20 mg / kg of the compound in a volume of 10 mL / kg prepared in 5% DMSO / 15% solutol% / 80% PBS (w / v). They had free access to water and food before the experiment.

[0439] Approximately 0.03 mL of venous blood was collected from the dorsal plantar vein of mice at 0.033 h, 0.083 h, 0.25 h, 0.5 h, 1 h, 2 h, 4 h, 8 h, and 24 h after intravenous administration. The blood was placed in an EDTA-K2 tube and centrifuged at 4000 g for 5 min at 4°C to separate the plasma. The concentration of the compound in the plasma was determined by liquid chromatography-tandem mass spectrometry.

[0440] Approximately 0.03 mL of venous blood was collected from the dorsal plantar vein of mice at 0.083 h, 0.25 h, 0.5 h, 1 h, 2 h, 4 h, 8 h, and 24 h after oral administration. The blood was placed in an EDTA-K2 tube and centrifuged at 4000 g for 5 min at 4°C to separate the plasma. The concentration of the compound in the plasma was determined by liquid chromatography-tandem mass spectrometry.

[0441] As shown in Table 4, the experimental results show that the compounds of the present application have low clearance rates, high plasma exposure amounts, and good oral absorption, especially Example 15, which has an oral bioavailability of up to 61.7% (in Table 4, Cl is clearance rate, F is bioavailability, and AUC is area under the curve).

[0442] Table 4

[0443] The applicant declares that this application uses the above-mentioned examples to illustrate the compounds of this application, their preparation, and use, but this application is not limited to these examples, that is, it does not mean that this application must rely on these examples for implementation. Those skilled in the art should understand that any improvements to this application, equivalent replacements of raw materials used in this application, addition of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of this application.

Claims

1. An imidazo[1,2-a]pyridine IRAK4 degrading agent, its stereoisomers, geometric isomers, tautomers, or pharmaceutically acceptable salts, wherein: The imidazo[1,2-a]pyridine IRAK4 degradation agent has a structure as shown in the following formula I: in, Ring A is a 6- to 10-membered aryl group or a 5- to 10-membered heteroaryl group; Ring B is a substituted or unsubstituted 4-10 membered cycloalkyl group or a substituted or unsubstituted 4-10 membered heterocycloalkyl group; Ring C is a substituted or unsubstituted 4-10 membered cycloalkyl group or a substituted or unsubstituted 4-10 membered heterocycloalkyl group; X is CH2 or C=O; R a Each is independently selected from halogen, cyano, substituted or unsubstituted C1-C4 alkyl, substituted or unsubstituted C1-C4 alkoxy, di(C1-C4 alkyl)amino, 5-10 membered cycloalkyl, 5-10 membered heterocycloalkyl; m is an integer from 0 to 5; R b Selected from C1-C4 alkoxy, C3-C6 cycloalkyloxy or hydroxydi(C1-C4 alkyl)methyl; R c is hydrogen, C1-C4 alkyl, C1-C4 alkoxy or halogen; and L is (CH2)n, (CH2) n CO, 4-8 membered cycloalkyl or 4-8 membered heterocycloalkyl, and n is an integer of 0-5.

2. The imidazo[1,2-a]pyridine IRAK4 degrading agent according to claim 1, its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, characterized in that: The substituent in the substituted group is selected from halogen, oxo, cyano, amino, hydroxyl, C1-C6 alkyl or -O-(C1-C6 alkyl).

3. The imidazo[1,2-a]pyridine IRAK4 degrading agent according to claim 1 or 2, its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, wherein: The ring A is The wavy line represents the attachment site of the group.

4. The imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 3, or its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, wherein: The ring B is The wavy line represents the attachment site of the group.

5. The imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 4, or its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, wherein: The ring C is The wavy line represents the attachment site of the group.

6. The imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 5, its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, wherein: R a are each independently selected from fluorine, chlorine, cyano, trifluoromethyl, trifluoromethoxy, The wavy lines represent the attachment sites of the groups; Preferably, R b is selected from methoxy, ethoxy, isopropoxy, cyclopropyloxy or Any of the following, the wavy line represents The attachment site of the group; Preferably, R c is selected from hydrogen, fluorine, chlorine or bromine; Preferably, L is -CH2-, -CH2CH2-, -CH2CH2CH2-, -COCH2-, -COCH2CH2-, -COCH2CH2CH2- or The wavy line represents the attachment site of the group.

7. The imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 6, or its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, wherein: The imidazo[1,2-a]pyridine IRAK degradation agent is selected from any one of the following compounds:

8. The imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 7, its stereoisomer, geometric isomer, tautomer or pharmaceutically acceptable salt, wherein: The pharmaceutically acceptable salts include any one of the following salts: sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogen phosphate, dihydrogen phosphate, metaphosphate, pyrophosphate, hydrochloride, hydrobromide, hydroiodide, acetate, propionate, decanoate, octanoate, acrylate, formate, isobutyrate, hexanoate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, malonate, The salts may be benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, sulfonates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, gamma-hydroxybutyrates, glycolates, tartrates, methanesulfonates, propanesulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates, or mandelates.

9. A pharmaceutical composition comprising the imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 8, or its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts.

10. Use of the imidazo[1,2-a]pyridine IRAK4 degrader according to any one of claims 1 to 9, its stereoisomers, geometric isomers, tautomers or pharmaceutically acceptable salts, or the pharmaceutical composition according to claim 8 in the preparation of a medicament for treating a disease or condition mediated by IRAK4.

11. The use according to claim 9, wherein: The disease includes an inflammatory disease, an autoimmune disease or a tumor; Preferably, the inflammatory disease is selected from Crohn's disease, ulcerative colitis, asthma, graft-versus-host disease, chronic obstructive pulmonary disease, atopic dermatitis, gout, gouty arthritis, conjunctivitis, hepatitis, chronic inflammatory lung disease, thyroiditis or interstitial cystitis; Preferably, the autoimmune disease is selected from Graves' disease, rheumatoid arthritis, systemic lupus erythematosus, lupus nephritis, cutaneous lupus, psoriasis, psoriatic arthritis, cryptopyrin-associated periodic syndrome, TNF receptor-associated periodic syndrome, multiple sclerosis, allergic rhinitis, scleroderma, dermatomyositis, vasculitis or nephritis; Preferably, the tumor is selected from lung cancer, breast cancer, prostate cancer, pancreatic cancer, kidney cancer, liver cancer, gastrointestinal cancer, cervical cancer, endometrial cancer, testicular cancer, genitourinary tract cancer, colorectal cancer, laryngeal cancer, skin cancer, bone cancer, head and neck tumors, sarcoma, brain tumor, glioblastoma, melanoma, multiple myeloma, lymphoma or leukemia.

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