An imine IDO inhibitor and its preparation and use

Abstract

The present invention relates to an imine IDO inhibitor, their preparation and therapeutic use. The imine IDO inhibitor comprises an imine compound shown in formula I or a pharmaceutically acceptable salt thereof, which can be used as an anti-tumor immunotherapy agent. The substituents shown in formula I are as described in the specification. The IDO inhibitor of the present invention is characterized in that: as an IDO inhibitor, it has excellent activity at the cellular level, and its IC 50 Less than 1μM. #imgabs0#

Description

Technical Field

[0001] The present invention belongs to the field of medicinal chemistry, and specifically relates to a class of imine compounds and their preparation methods as therapeutic drugs, especially for use in tumor immunotherapy by inhibiting tryptophan metabolism. The biomarkers involved include but are not limited to IDO1 (indoleamine 2,3-dioxygenase 1). Background Art

[0002] According to the International Agency for Research on Cancer (IARC), the number of cancer patients worldwide will reach 24 million by 2030. In recent years, immunotherapy has become a hot topic in precision cancer medicine and has gradually developed into the fourth tumor treatment modality after surgery, chemotherapy, and radiotherapy. Indoleamine 2,3-dioxygenase (IDO) is an iron-containing heme monomer protein that catalyzes the oxidative cleavage of the indole ring of L-tryptophan using superoxide anions as a cofactor. It is distributed in tissues and cells other than the liver in humans and other mammals. IDO1 plays an important regulatory role in suppressing T cell immunity and inducing tumor immune tolerance. In healthy humans, IDO1 expression levels are low, but during infection and inflammation, IDO1 expression increases significantly, particularly in various tumor tissues. Tumor cells can recruit dendritic cells expressing IDO1 into the tumor microenvironment, so IDO1 is also highly expressed in many human tumor tissues and draining lymph nodes, such as ovarian cancer, lung cancer, chronic lymphocytic leukemia, etc.

[0003] IDO has become a popular target for tumor immunotherapy. In clinical trials, various small-molecule IDO inhibitors, combined with antibody-based immunotherapies, have demonstrated excellent efficacy against some difficult-to-treat cancers. Currently, there are over 50 IDO inhibitors under development worldwide, including one in Phase III clinical trials, two in Phase II clinical trials, seven in Phase I clinical trials, and 30 in the preclinical stage. The development of targeted small-molecule drugs that act on IDO and the resulting more active and selective IDO inhibitors are of crucial social and economic significance.

[0004] IDO inhibitors can be divided into three categories: competitive inhibitors represented by epacadostat, non-competitive inhibitors represented by navoximod, and other types of inhibitors. Among them, competitive inhibitors are the fastest-growing. Epacadostat and 1-methyltryptophan (1-MT) exert their inhibitory effects by competitively binding with tryptophan to the IDO catalytic region, thereby effectively intervening in the tryptophan metabolism process, enhancing the proliferation of effector T cells and natural killer cells, reducing apoptosis, and inhibiting CD86 + Increased dendritic cell activation.

[0005] 1-Methyltryptophan (1-MT) is a derivative obtained in the 1990s by structurally modifying the IDO substrate tryptophan as a template. It is currently a commonly used IDO inhibitor in in vitro and in vivo experiments, with an inhibition constant (Ki) of 34uM. The structural formula of 1-MT is shown below:

[0006]

[0007] Chinese patent CN109111438A discloses a series of amidine compounds used as IDO inhibitors. However, the inventors did not conduct further activity studies on these compounds, only determining the IDO enzyme inhibitory activity of the compounds in Examples 16, 17, and 19. Therefore, these examples can only demonstrate extracellular IDO inhibition. Because the patent does not report intracellular or in vivo antiproliferative activity data for any of the examples, and given the significant differences between the activity testing environments described in the patent and those in vivo, these compounds cannot be considered to possess antitumor activity.

[0008] In order to develop inhibitors with new structures, the present invention provides a compound with IDO inhibitory effect and its application. The new compound of the present invention is characterized in that: the compound has excellent activity at the cellular level as an IDO inhibitor, and its IC 50 Less than 1μM. Summary of the Invention

[0009] The present invention provides a class of compounds that can inhibit IDO1 activity and can be used as therapeutic or alleviating drugs for tumors.

[0010] Specifically, the present invention provides an imine compound as shown in Formula I or a pharmaceutically acceptable salt thereof:

[0011]

[0012] in:

[0013] R1 is hydroxy, substituted or unsubstituted 5-8 membered aryl or heteroaryl;

[0014] R2 is a cyano group, a substituted or unsubstituted 5-8 membered aromatic amino group;

[0015] W is selected from C and N;

[0016] X is selected from C and N;

[0017] Y is selected from C and N;

[0018] Z is selected from C and N;

[0019] Wherein, W and X are not N at the same time, and Y and Z are not C at the same time. Preferably,

[0020] R1 is a hydroxyl group or a substituted 5-8 membered aryl group,

[0021] R2 is a cyano group, or a substituted 5-8 membered arylamino group.

[0022] More preferably,

[0023] R1 is hydroxyl or substituted phenyl,

[0024] R2 is cyano or substituted phenylamino.

[0025] Further preferably,

[0026] R1 is hydroxyl, or phenyl substituted with halogen,

[0027] R2 is cyano or halogen-substituted phenylamino.

[0028] More preferably,

[0029] R1 is hydroxyl, or

[0030] R2 is cyano, or

[0031] Most preferably,

[0032] The imine compound of the present invention is selected from:

[0033]

[0034] The pharmaceutically acceptable salts of the imine compounds of the present invention are salts formed by the imine compounds of the present invention and the following acids: hydrochloric acid, p-toluenesulfonic acid, tartaric acid, maleic acid, lactic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, citric acid, acetic acid or trifluoroacetic acid.

[0035] Preferably, the salt is formed between the imine compound and the following acid: p-toluenesulfonic acid, hydrochloric acid, tartaric acid or trifluoroacetic acid.

[0036] The pharmaceutically acceptable salts of the imine compounds of the present invention further include their solvates, metabolites, prodrugs, etc.

[0037] The present invention also provides a pharmaceutical composition containing the imine compound of the present invention or a pharmaceutically acceptable salt thereof.

[0038] The pharmaceutical composition of the present invention is preferably in the form of a unit dose pharmaceutical preparation. When the pharmaceutical preparation is prepared, it can be made into any pharmaceutically acceptable dosage form, which is selected from the group consisting of tablets, sugar-coated tablets, film-coated tablets, enteric-coated tablets, capsules, hard capsules, soft capsules, oral liquids, buccal preparations, granules, suspensions, solutions, injections, suppositories, ointments, plasters, creams, sprays, and patches. Oral preparations are preferred, and tablets and capsules are most preferred.

[0039] Furthermore, the pharmaceutical composition of the present invention also contains a pharmaceutically acceptable carrier.

[0040] The pharmaceutical preparation can be prepared by conventional pharmaceutics techniques, such as mixing the imine compound of the present invention, or a solvate thereof, or a pharmaceutically acceptable salt of the imine compound, or a pharmaceutically acceptable salt of a solvate thereof with a pharmaceutically acceptable carrier. The pharmaceutically acceptable carrier includes, but is not limited to, mannitol, sorbitol, sorbic acid or potassium salt, sodium metabisulfite, sodium bisulfite, sodium thiosulfate, cysteine ​​hydrochloride, thioglycolic acid, methionine, vitamin A, vitamin C, vitamin E, vitamin D, azone, disodium EDTA, calcium sodium EDTA, carbonates, acetates, phosphates of monovalent alkali metals or their aqueous solutions, hydrochloric acid, acetic acid, sulfuric acid, phosphoric acid, amino acids, sodium chloride, potassium chloride, sodium lactate, xylitol, maltose, glucose, fructose, dextrorotatory Glycosides, glycine, starch, sucrose, lactose, mannitol, silicon derivatives, cellulose and its derivatives, alginate, gelatin, polyvinyl pyrrolidone, glycerin, propylene glycol, ethanol, Teflon 60-80, Span-80, beeswax, lanolin, liquid paraffin, cetyl alcohol, gallic acid esters, agar, triethanolamine, basic amino acids, urea, allantoin, calcium carbonate, calcium bicarbonate, surfactants, polyethylene glycol, cyclodextrin, β-cyclodextrin, phospholipid materials, kaolin, talc, calcium stearate, magnesium stearate, etc.

[0041] The pharmaceutical composition of the present invention, when prepared as a medicament, may contain 0.1-1000 mg of the pharmaceutical active substance of the present invention per unit dose, with the remainder being a pharmaceutically acceptable carrier, which may account for 0.1-99.9% of the total weight of the preparation.

[0042] The dosage and administration of the pharmaceutical composition of the present invention are determined according to the patient's condition.

[0043] The present invention also includes the use of the imine compound, or a pharmaceutically acceptable salt thereof, and a pharmaceutical composition containing the imine compound or a pharmaceutically acceptable salt thereof in preparing a drug for treating diseases associated with IDO1.

[0044] The diseases associated with IDO1 are not limited to tumors. The types of cancer that can be treated with the compounds of the present invention include, but are not limited to, brain cancer, skin cancer, bladder cancer, ovarian cancer, breast cancer, stomach cancer, pancreatic cancer, prostate cancer, colon cancer, blood cancer, lung cancer, and bone cancer. Examples of the above cancer types include neuroblastoma; intestinal cancers such as rectal cancer, colon cancer, familial adenomatous polyposis carcinoma, and hereditary non-polyposis colorectal cancer; esophageal cancer; lip cancer; laryngeal cancer; hypopharyngeal cancer; tongue cancer; salivary gland cancer; gastric cancer; adenocarcinoma; medullary thyroid cancer; papillary thyroid cancer; kidney cancer; renal parenchymal cancer; ovarian cancer; cervical cancer; uterine corpus cancer; endometrial cancer; choriocarcinoma; pancreatic cancer; prostate cancer; testicular cancer; breast cancer; urinary cancer; melanoma; brain tumors such as glioblastoma, astrocytoma, meningioma, medulloblastoma, and peripheral neuroectodermal tumor; Hodgkin lymphoma carcinoma; non-Hodgkin's lymphoma; Burkitt's lymphoma; acute lymphocytic leukemia (ALL); chronic lymphocytic leukemia (AML); chronic myeloid leukemia (CML); adult T-cell leukemia lymphoma; diffuse large B-cell lymphoma (DLBCL); hepatocellular carcinoma; gallbladder cancer; bronchogenic carcinoma; small cell lung cancer; non-small cell lung cancer; multiple myeloma; basal cell tumor; teratoma; retinoblastoma; choroidal melanoma; seminoma; rhabdomyosarcoma; craniopharyngioma; osteosarcoma; chondrosarcoma; myeloma; liposarcoma; fibrosarcoma; Ewing sarcoma and plasmacytoma.

[0045] The compounds of the present invention can be prepared by the following preparation methods:

[0046] Option 1:

[0047]

[0048] In scheme 1, 3-bromo-4-fluoroaniline is used as a raw material and condensed with indole-7-carboxylic acid under alkaline conditions to obtain compound 1-2. Compound 1-2 is thiolated with Lawesson's reagent to obtain compound 1-3. Compound 1-3 reacts with hydroxylamine hydrochloride to obtain compound 1.

[0049] Option 2:

[0050]

[0051] In scheme 2, 4-indolecarboxaldehyde is used as the raw material, and compound 2-2 is obtained by BOC protection. Compound 2-2 reacts with hydroxylamine hydrochloride to obtain compound 2-3. Compound 2-3 is chlorinated to obtain compound 2-4. Compound 2-4 reacts with 3-bromo-4-fluoroaniline to obtain compound 2-5. Compound 2-5 is deprotected to obtain compound 2.

[0052] Option 3:

[0053]

[0054] In scheme 3, 4-indolecarboxaldehyde is used as the raw material, and compound 3 is obtained by condensation with 3-bromo-4-fluoroaniline and cyanation.

[0055] Option 4:

[0056]

[0057] In Scheme 4, 7-indolecarboxaldehyde is used as the raw material, and compound 4 is obtained by condensation with 3-bromo-4-fluoroaniline and cyanation.

[0058] Option 5:

[0059]

[0060] In Scheme 5, methyl 2-amino-3-nitrobenzoate is used as the raw material, and compound 5-2 is obtained by reduction condensation. Compound 5-2 is reduced and oxidized to obtain compound 5-4. Compound 5-4 is condensed with 3-bromo-4-fluoroaniline and cyanated to obtain compound 5.

[0061] Option 6:

[0062]

[0063] In scheme six, 7-chloro-1H-pyrrolo[3,2-b]pyridine is used as the raw material, and compound 6-2 is obtained through carbon monoxide coupling and esterification. Compound 6-2 is reduced and oxidized to obtain compound 6-4. Compound 6-4 is condensed with 3-bromo-4-fluoroaniline and cyanated to obtain compound 6.

[0064] Option 7:

[0065]

[0066] In Scheme 7, 7-bromo-1H-pyrrolo[3,2-c]pyridine is used as the raw material, and carbon monoxide coupling and esterification are performed to obtain compound 7-2. Compound 7-2 is reduced and oxidized to obtain compound 7-4. Compound 7-4 is condensed with 3-bromo-4-fluoroaniline and cyanated to obtain compound 7. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 Compound 1 1 H-NMR spectrum

[0068] Figure 2. Compound 2 1 H-NMR spectrum

[0069] Figure 3 Compound 3 1 H-NMR spectrum

[0070] Figure 4. Compound 4 1 H-NMR spectrum

[0071] Figure 5. Compound 5 1 H-NMR spectrum

[0072] Figure 6. Compound 6 1 H-NMR spectrum

[0073] Figure 7 Compound 7 1 H-NMR spectrum DETAILED DESCRIPTION

[0074] Example 1: Synthesis of Compound 1

[0075] a. Synthesis of Compound 1-2

[0076]

[0077] Dissolve 3-bromo-4-fluoroaniline (1.89 g, 10 mmol) and indole-7-carboxylic acid (1.61 g, 10 mmol) in 20 mL of DCM. Add triethylamine (3.03 g, 30 mmol) and HATU (3.8 g, 10 mmol) with stirring. Stir the reaction mixture at room temperature for 2 hours. After completion of the reaction, concentrate the mixture under reduced pressure. The crude product is purified by column chromatography to yield 2.0 g of a white solid in a 61% yield.

[0078] b. Synthesis of Compounds 1-3

[0079]

[0080] Compound 1-2 (1 g, 3 mmol) was dissolved in toluene (10 mL), and Lawesson's reagent (0.97 g, 2.4 mmol) was added. The reaction mixture was heated to reflux and allowed to react for 14 h. After completion of the reaction, the reaction mixture was concentrated under reduced pressure. The crude product was purified by column chromatography to obtain 0.62 g of a white solid in a 52.7% yield.

[0081] c. Synthesis of Compound 1

[0082]

[0083] Under argon, compound 1-3 (620 g, 1.78 mmol), hydroxylamine hydrochloride (614 mg, 8.9 mmol), and sodium bicarbonate (1.498 g, 17.8 mmol) were added to 20 mL of ethanol. The reaction mixture was heated to 70°C and allowed to react for 10 hours. After completion, the mixture was cooled to room temperature. The reaction mixture was filtered, and the filter cake was washed with ethyl acetate. The filtrate was collected and concentrated under reduced pressure. The crude product was purified by column chromatography to yield 0.126 g of a light yellow solid (20% yield).

[0084] MS Found:348.2[M+H] + ,350.2[M+2+H] + .

[0085] Example 2: Synthesis of Compound 2

[0086] a. Synthesis of Compound 2-2

[0087]

[0088] Under nitrogen, potassium tert-butoxide (2.9 g, 25.8 mmol) and di-tert-butyl dicarbonate (4.5 g, 20.6 mmol) were added to 4-indolecarboxaldehyde (2.5 g, 17.2 mmol) in 50 mL of anhydrous THF. The reaction was allowed to react at room temperature for 12 h. After completion, the reaction solution was concentrated and extracted with ethyl acetate (50 mL x 3). The organic phases were combined and dried over sodium sulfate. The crude product was filtered and concentrated under reduced pressure. Column chromatography (0-10% EA in PE) afforded 1.7 g of a white solid, yielding 40.3%. MS Found: 246.2 [M+H] + .

[0089] b. Synthesis of Compound 2-3

[0090]

[0091] Under nitrogen, hydroxylamine hydrochloride (2.1 g, 30.2 mmol) was added to a solution of compound 2-2 (1.5 g, 6.1 mmol) in ethanol (50 mL). The reaction mixture was heated to 70°C for 4 h. After completion of the reaction, the reaction mixture was concentrated under reduced pressure and extracted with ethyl acetate (50 mL x 3). The organic phases were combined, concentrated, and washed with petroleum ether to obtain 1.2 g of an off-white solid (yield 75.6%). MS Found: 261.2 [M+H] +

[0092] c. Synthesis of Compounds 2-4

[0093]

[0094] Compound 2-3 (1.2 g, 4.6 mmol) and NCS (748.0 mg, 5.6 mmol) were added to DMF (30 mL). The reaction mixture was heated to 50°C and continued for 12 h. After completion, the reaction mixture was poured into water and extracted with ethyl acetate (30 mL x 3). The organic phases were combined and dried over sodium sulfate. The organic phases were filtered and concentrated under reduced pressure. The crude product was purified by column chromatography (10-30% EA in PE) to afford 0.708 g of an off-white solid in a 52.2% yield. MS Found: 295.0 [M+H] + ,297.0[M+2+H] + .

[0095] d. Synthesis of Compounds 2-5

[0096]

[0097] Compound 2-4 (707.4 mg, 2.4 mmol), EDCI (460.1 mg, 2.4 mmol), and pyridine (379.7 mg, 4.8 mmol) were added to 10 mL of THF. The reaction was allowed to react at room temperature for 12 h. After completion, the reaction was quenched with water and extracted with ethyl acetate (30 mL x 3). The combined organic phases were washed with saturated brine (30 mL) and dried over sodium sulfate. The organic phase was filtered and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (10-40% EA in PE) to obtain 0.5 g of an off-white solid, with a yield of 46.5%. MS Found: 448.0 [M+H] + ,450.0[M +2+H] + .

[0098] e. Synthesis of Compound 2

[0099]

[0100] To a solution of compound 2-5 (493.1 mg, 1.1 mmol) in DCM (10 mL) was added trifluoroacetic acid (1 mL). The reaction was allowed to react at 30°C for 12 h. The reaction solution was concentrated under reduced pressure and extracted with DCM (20 mL x 3). The organic phases were combined and concentrated to yield the crude product. The crude product was purified by prep-HPLC to yield 94.1 mg of a white solid in a 24.6% yield. MS Found: 348.1 [M+H] + ,350.1[M+2+H] + . 1H NMR (400MHz, DMSO-d6): δ6.38(s,1H),6.51-6.55(m,1H),6.91-6.99(m,2H),7.06-7.11(m,2H), 7.29-7.41(m,1H),7.42(dd,J=4.8,2.0Hz,1H),8.58(m,1H),10.54(m,1H),11.17(m,1H).

[0101] Example 3: Synthesis of Compound 3

[0102]

[0103] To a solution of 4-indolecarboxaldehyde (725.8 mg, 5.0 mmol) in TFE / ACN (40 mL, v / v = 1:1) was added 3-bromo-4-fluoroaniline (950.1 mg, 5.0 mmol). The reaction was allowed to react at room temperature for 1 h. The reaction solution was concentrated and dissolved in a DCM / TFE mixture (20 mL, v / v = 1:1), followed by the addition of TMSCN (595.3 mg, 6.0 mmol). The reaction was allowed to react at room temperature for 3 h. The reaction solution was concentrated again and reconstituted in CHCl3 / THF (40 mL, v / v = 1:1). Manganese dioxide (4.3 g, 49.4 mmol) was added, and the reaction solution was heated to reflux and allowed to react for 2 days. After completion of the reaction, the mixture was filtered, and the filter cake was washed with methanol. The filtrate was collected and concentrated under reduced pressure to obtain the crude product. The crude product was purified by prep-HPLC to yield 0.12 g of a yellow solid in a 7.0% yield. MS Found:342.1[M+H] + ; 344.1[M+2+H] + . 1 H NMR (400MHz, DMSO-d6): δ7.24 (t, J=2.0Hz, 1H), 7.35-7.39(m,2H),7.55(t,J=8.8Hz,1H),7.65(t,J=2.8Hz,1H),7.72(dd,J=6.0,2.4Hz,1H),7.78-7.81(m,2H),11.75(s,1H).

[0104] Example 4: Synthesis of Compound 4

[0105]

[0106] To a solution of 7-indolecarboxaldehyde (725.8 mg, 5.0 mmol) in TFE / ACN (40 mL, v / v = 1:1) was added 3-bromo-4-fluoroaniline (950.1 mg, 5.0 mmol). The reaction was stirred at room temperature for 1 h. The reaction solution was concentrated, and the residue was dissolved in DCM / TFE (20 mL, v / v = 1:1) and TMSCN (595.3 mg, 6.0 mmol) was added. The reaction was continued at room temperature for 3 h. The reaction solution was concentrated again, and the crude product was used CHCl3 The solution was redissolved in 40 mL of 4% paraformaldehyde (THF) (v / v = 1:1) and manganese dioxide (4.3 g, 49.4 mmol) was added. The reaction mixture was heated to reflux and the reaction was continued for 2 days. After completion of the reaction, the mixture was filtered and the filter cake was washed with methanol. The filtrate was collected and concentrated under reduced pressure to obtain the crude product. The crude product was purified by prep-HPLC to obtain 0.106 g of a yellow solid in a yield of 6.2%. MS Found: 342.1 [M+H] + ; 344.1[M+H] + . 1 H NMR (400MHz, DMSO-d6): δ6.68(dd,J=3.2,2.0Hz,1H), 7.32(t,J=7.6Hz,1H),7.48-7.52(m,2H),7.59(t,J=8.8Hz,1H),7.80(d,J=7.6 Hz, 1H), 7.85 (dd, J = 6.4, 2.4Hz, 1H), 7.98 (d, J = 7.6Hz, 1H), 11.50 (s, 1H).

[0107] Example 5: Synthesis of Compound 5

[0108] a. Synthesis of Compound 5-2

[0109]

[0110] To a solution of methyl 2-amino-3-nitrobenzoate (3.9 g, 19.9 mmol) in isopropanol (30 mL) were added iron powder (5.6 g, 100.3 mmol), ammonium chloride (5.6 g, 104.7 mmol), and formic acid (20 mL). The reaction solution was heated to 80°C and allowed to react for 12 hours. After completion of the reaction, the filtrate was collected and concentrated to obtain the crude product. The crude product was purified by column chromatography (10-50% EA in PE) to obtain 3.0 g of an off-white solid, with a yield of 85.6%. MS Found: 177.0 [M+H] + .

[0111] b. Synthesis of Compound 5-3

[0112]

[0113] To a solution of compound 5-2 (3.0 g, 17.0 mmol) in THF (100 mL) was slowly added LiAlH4 (1.3 g, 34.3 mmol) at room temperature and stirred overnight. After completion of the reaction, the mixture was quenched with water and extracted with ethyl acetate (50 mL x 3). The organic phase was collected and concentrated to yield the crude product. The crude product was purified by column chromatography (20-60% EA in PE) to afford 2.0 g of an off-white solid in a 79.4% yield. MS Found: 149.2 [M+H] + .

[0114] c. Synthesis of Compound 5-4

[0115]

[0116] To a solution of compound 5-3 (2.0 g, 13.5 mmol) in DCM (50 mL) at room temperature was added manganese dioxide (11.7 g, 134.6 mmol). The reaction mixture was heated to reflux and allowed to react overnight. After completion of the reaction, the reaction mixture was filtered, and the filtrate was collected and concentrated to obtain the crude product. The crude product was purified by column chromatography (20-60% EA in PE) to afford 0.6 g of an off-white solid in a 30.4% yield. MS Found: 147.0 [M+H] + .

[0117] d. Synthesis of Compound 5

[0118]

[0119] To a solution of compound 5-4 (600.0 mg, 4.1 mmol) in TFE / ACN (40 mL, v / v = 1:1) at room temperature was added 3-bromo-4-fluoroaniline (950.1 mg, 5.0 mmol) and stirring continued for 1 hour. The reaction mixture was concentrated, the residue was dissolved in DCM / TFE (20 mL, v / v = 1:1), and TMSCN (595.3 mg, 6.0 mmol) was added. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was concentrated again and reconstituted in CHCl3 / THF (40 mL, v / v = 1:1), followed by the addition of manganese dioxide (4.3 g, 49.5 mmol). The reaction mixture was heated to reflux and allowed to react for 2 days. After completion of the reaction, the reaction mixture was filtered, and the filter cake was washed with methanol. The filtrate was collected and concentrated under reduced pressure to obtain the crude product. The crude product was purified by prep-HPLC to obtain 0.132 g of a yellow solid in a 9.4% yield. MS Found:343.0[M+H] + ; 345.0[M+H+2] + . 1H NMR (400MHz, CDCl3): δ7.21-7.30 (m, 2H), 7.49-7.53 (m, 2H), 8.03 (d, J = 7.6Hz, 1H), 8.13 (d, J = 8.0Hz, 1H), 8.22 (s, 1H), 11.00 (brs, 1H).

[0120] Example 6: Synthesis of Compound 6

[0121] a. Synthesis of Compound 6-2

[0122]

[0123] 7-Chloro-1H-pyrrolo[3,2-b]pyridine (2.7 g, 17.7 mmol), Pd(dppf)Cl2 (658.5 mg, 0.9 mmol), and Et3N (2.8 g, 27.7 mmol) were added to 20 mL of ethanol at room temperature. The mixture was refluxed under a carbon monoxide balloon for 12 hours. After completion of the reaction, the mixture was filtered and the filtrate was concentrated to obtain the crude product. The crude product was purified by column chromatography (20-40% EA in PE) to obtain 1.6 g of an off-white solid in a 47.5% yield. MS Found: 191.2 [M+H] + .

[0124] b. Synthesis of Compound 6-3

[0125]

[0126] To a solution of compound 6-2 (1.6 g, 8.4 mmol) in THF (30 mL) was slowly added LiAlH4 (0.9 g, 23.7 mmol) at room temperature and stirred overnight. After completion of the reaction, the mixture was quenched with water and extracted with ethyl acetate (20 mL x 3). The combined organic phases were dried over sodium sulfate. Filtration and concentration of the organic phases afforded 0.98 g of a crude gray solid (78.7% yield), which was used directly in the next reaction without purification.

[0127] c. Synthesis of Compound 6-4

[0128]

[0129] To a solution of compound 6-4 (977.9 mg, 6.6 mmol) in DCM (30 mL) at room temperature was added manganese dioxide (4.6 g, 52.9 mmol), heated to reflux, and allowed to react overnight. After completion of the reaction, the reaction solution was filtered and the filtrate was concentrated to obtain the crude product. The crude product was purified by column chromatography (20-60% EA in PE) to afford 0.7 g of an off-white solid in a yield of 72.6%. MS Found: 147.3 [M+H]+ .

[0130] d. Synthesis of Compound 6-5

[0131]

[0132] To a solution of compound 6-4 (686.9 mg, 4.7 mmol) in TFE / ACN (40 mL, v / v = 1:1) was added 3-bromo-4-fluoroaniline and a catalytic amount of acetic acid at room temperature. The reaction mixture was stirred overnight. After completion of the reaction, the reaction solution was concentrated to obtain a crude product. The crude product was purified by column chromatography (20-60% EA in PE) to afford 1.2 g of an off-white solid in an 80.3% yield.

[0133] e. Synthesis of Compound 6

[0134]

[0135] To a solution of compound 6-5 (318.1 mg, 1.0 mmol) in ACN (20 mL) were added TMSCN (496.1 mg, 5.0 mmol), Zn(CN)2 (11.7 mg, 0.1 mmol), and AlCl3 (13.3 mg, 0.1 mmol), respectively. The reaction was stirred at 50°C for 4 h. Manganese dioxide (434.7 mg, 5.0 mmol) was then added to the reaction solution, and the reaction solution was heated to 80°C overnight. After the reaction was completed, the reaction solution was filtered, and the filter cake was washed with ethyl acetate. The filtrate was collected and concentrated to obtain the crude product. The crude product was purified layer by layer (50% of EA in PE) to obtain 0.25 g of a yellow solid, with a yield of 72.9%. MS Found: 343.0 [M+H] + ,345.0[M+2+H] + .. 1 H NMR (400MHz, DMSO-d6): δ6.78-6.79(m,1H),7.58-7.65(m,3H),7.78(d,J=3.2Hz, 1H), 7.93 (dd, J=4.0, 2.0Hz, 1H), 8.65 (d, J=5.2Hz, 1H), 11.60 (brs, 1H).

[0136] Example 7: Synthesis of Compound 7

[0137] a. Synthesis of Compound 7-2

[0138]

[0139] To a solution of 7-bromo-1H-pyrrolo[3,2-c]pyridine (1.8 g, 9.1 mmol) in ethanol (20 mL) was added Pd(dppf)Cl2 (658.5 mg, 0.9 mmol) and triethylamine (2.8 g, 27.7 mmol) at room temperature. The mixture was refluxed under a carbon monoxide balloon for 12 hours. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated to obtain the crude product. The crude product was purified by column chromatography (20-40% EA in PE) to afford 1.4 g of an off-white solid in an 80.9% yield.

[0140] b. Synthesis of Compound 7-3

[0141]

[0142] At room temperature, LiAlH4 (0.6 g, 15.8 mmol) was slowly added to a solution of compound 7-2 (1.4 g, 7.4 mmol) in THF (30 mL). The reaction was stirred overnight. After completion, the reaction was quenched with water and extracted with ethyl acetate (20 mL x 3). The organic phase was collected and dried over sodium sulfate. Filtered and concentrated to obtain the crude product. The crude product was purified by column chromatography (20-60% EA in PE) to obtain 0.8 g of an off-white solid, with a yield of 73.0%. MS Found: 149.2 [M+H] + .

[0143] c. Synthesis of Compound 7-4

[0144]

[0145] To a solution of compound 7-3 (800 mg, 5.4 mmol) in DCM (30 mL) was added manganese dioxide (4.6 g, 52.9 mmol) at room temperature and the mixture was refluxed overnight. After completion of the reaction, the reaction solution was filtered and the filtrate was concentrated to obtain the crude product. The crude product was purified by column chromatography (20-60% EA in PE) to afford 0.6 g of an off-white solid in a yield of 76.0%. MS Found: 147.3 [M+H] + .

[0146] d. Synthesis of Compound 7-5

[0147]

[0148] To a solution of compound 7-4 (599.2 mg, 4.1 mmol) in TFE / ACN (40 mL, v / v = 1:1) at room temperature were added 3-bromo-4-fluoroaniline (779.0 mg, 4.1 mmol) and a catalytic amount of acetic acid. The mixture was stirred and allowed to react overnight. After completion of the reaction, the crude product was concentrated. The crude product was purified by column chromatography (20-60% EA in PE) to afford 0.58 g of an off-white solid, in a yield of 44.5%. MS Found: 318.0 [M+H] + ,320.0[M+2+H] + .

[0149] e. Synthesis of Compound 7

[0150]

[0151] To a solution of compound 7-5 (572.7 mg, 1.8 mmol) in CHCl3 / THF (40 mL, v / v = 1:1) were added TMSCN (813.5 mg, 8.2 mmol) and manganese dioxide (1.8 g, 20.7 mmol). The mixture was heated to 80°C and reacted for 24 h. After completion of the reaction, the reaction mixture was filtered and the filter cake was washed with methanol. The filtrate was collected and concentrated to obtain the crude product. The crude product was purified by prep-HPLC to obtain 0.13 g of a yellow solid in a yield of 21.4%. MS Found: 343.0 [M + H] + ,345.0[M+2+H] + . 1 H NMR (400MHz, DMSO-d6): δ6.83-6.84(m,1H), 7.53-7.63(m,3H),7.87(dd,J=3.6,2.4Hz,1H),8.77(s,1H),9.11(s,1H),11.84(brs,1H).

[0152] Example 8: Inhibition of IDO1 activity in Hela cells by compounds

[0153] Method process:

[0154] (1) Reagents, materials, devices, and instruments

[0155] RPMI 1640 medium, phenol red-free (1X) (Invitrogen-11835-030); 0.05% trypsin-EDTA (1X) (Invitrogen-25300-062, batch number: 1391603); recombinant human interferon-γ, trichloroacetic acid (TCA), 4-dimethylaminobenzaldehyde, glacial acetic acid; RPMI 1640 medium (1X) 500 ml, final concentration 10%; penicillin / streptomycin (100x): final concentration 100 units / ml penicillin, 100 μg / ml streptomycin; Spectramax 340 PC (Molecular Devices).

[0156] (2) Methods and operations

[0157] Day 1:

[0158] (1) Discard the culture medium.

[0159] (2) Rinse the cell layer with 10 ml of PBS solution to remove trypsin inhibitors.

[0160] (3) Add 3 ml of 0.05% trypsin EDTA to the bottle and incubate at 37°C for 3-5 minutes.

[0161] (4) Add 10 ml of complete growth medium to each bottle and gently pipette the cells.

[0162] (5) Transfer the cell suspension to a 50 ml conical tube.

[0163] (6) Centrifuge the cells at room temperature, 1000 rpm, for 5 min.

[0164] (7) Count the cell concentration and determine the cell viability.

[0165] (8) Seed cells were seeded into 96-well plates at 200,000 cells per well.

[0166] (10) Add 100 μl of IFN-γ at a concentration of 100 ng / ml to the entire plate.

[0167] (11) Add compounds at different concentrations.

[0168] (12) The cells were cultured in a 37°C 5% CO2 incubator for 20 h.

[0169] the next day:

[0170] (1) Trichloroacetic acid was reduced from 30% to 0.2%. The cell plate was incubated at 50°C for 30 min.

[0171] (2) Centrifuge at 2400 rpm for 10 minutes.

[0172] (3) Add Ehrlich reagent.

[0173] (4) Measure the absorbance at 490 nm.

[0174] (5) Calculate IC 50 value.

[0175] Table 1 Inhibitory activity of selected compounds on IDO1 in Hela cells

[0176]

[0177] The "A" in the table represents the IC of the example compound. 50 The value is less than 1 μM, and “B” represents the IC value of the example compound. 50 The values ​​are between 1 μM and 10 μM, and “C” represents the IC of the example compounds. 50 The value is greater than 10 μM.

Claims

1. An imine compound or a pharmaceutically acceptable salt thereof, selected from:

2. The imine compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein the pharmaceutically acceptable salt is a salt formed by the imine compound and the following acids: hydrochloric acid, p-toluenesulfonic acid, tartaric acid, maleic acid, lactic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, citric acid, acetic acid or trifluoroacetic acid.

3. A pharmaceutical composition comprising the imine compound according to claim 1 or a pharmaceutically acceptable salt thereof.

4. Use of the imine compound or a pharmaceutically acceptable salt thereof according to claim 1, or the pharmaceutical composition containing the imine compound or a pharmaceutically acceptable salt thereof according to claim 3 in the preparation of a drug for treating tumors.

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