An iron chelator, its preparation method and use in the preparation of a drug for ameliorating iron overload

Abstract

The application discloses an iron chelator, a preparation method thereof and application thereof in preparing a medicine for improving iron overload, and belongs to the technical field of organic synthesis. The iron chelator is a compound shown in formula (I), stereoisomers, tautomers, crystalline hydrates, solvates, prodrugs or pharmaceutically acceptable salts of the iron chelator, wherein R is a substituted or unsubstituted phenyl or a substituted or unsubstituted furanyl, the substituent of the phenyl is an alkyl or an alkoxy, and the substituent of the furanyl is an alkyl; R1 is H or halogen; R2 is H, a carboxyl or a trihalomethyl; and R3 is H, a carboxyl or a carboxylate. The iron chelator has an iron ion removing effect in two kinds of cells, is oral and small-dose, and provides technical support for clinical application of improving iron overload of patients with red blood cell diseases caused by repeated blood transfusion.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to an iron chelating agent, its preparation method, and its application in the preparation of drugs that improve iron overload. Background Technology

[0002] Regular red blood cell transfusions are a primary treatment for anemia diseases such as severe thalassemia, myelodysplastic syndrome (MDS), and aplastic anemia, and are crucial for maintaining patients' quality of life. However, with increased red blood cell transfusion volumes and increased intestinal iron absorption due to ineffective bone marrow hematopoiesis, secondary iron overload significantly impacts the survival of these transfusion-dependent patients. Therefore, monitoring iron overload and providing timely iron chelation therapy in these patients is essential for controlling iron overload, protecting organ function, and prolonging patient survival. Clinically, there are other diseases that cause chronic anemia, such as hereditary hemochromatosis, aplastic anemia, congenital bone marrow failure diseases (such as Diamond-Blackfan syndrome and congenital erythroid dysplasia anemia), pure red cell aplasia, paroxysmal nocturnal hemoglobinuria, primary myelofibrosis, and patients who are dependent on red blood cell transfusion and need to receive hematopoietic stem cell transplantation (HSCT). These conditions can lead to secondary iron overload due to red blood cell transfusion. Considering that the mechanisms of red blood cell transfusion-dependent chronic iron overload are similar, their diagnosis and treatment can refer to the iron overload treatment principles of MDS.

[0003] Iron chelators are one of the main methods for treating iron overload. They selectively bind excess iron and promote iron excretion, thereby reducing the patient's iron load. Currently, the three main iron chelators used clinically are: desferrioxamine (DFO), deferiprone (DFP), and deferasirox (DFX). Effective iron chelation therapy can reduce the body's iron load, alleviate the harm of iron overload, and significantly improve disease prognosis.

[0004] Deferroamine is a chelating agent for ferric ions, capable of binding with ferric ions to form ferroamine complexes, with the following structural formula: .

[0005] Administered via intravenous or infusion pump via continuous subcutaneous injection, this medication has a short half-life of only 20 minutes, requiring each injection to last at least 8-12 hours and 5-7 times per week. This inconvenience for patients negatively impacts medication adherence. Long-term use may occasionally cause cataracts and developmental disorders of long bones in children; excessive doses can lead to visual and hearing impairment.

[0006] Deferiphenone is an oral iron chelator with a didentate projection. Its chemical name is 1,2-dimethyl-3-hydroxy-4-pyridone, and its structural formula is as follows: .

[0007] After oral administration, it is rapidly absorbed through the upper gastrointestinal tract, with a metabolic half-life of 3-4 hours. Common adverse reactions of deferiphenone include arthralgia (mainly large joints), transient elevation of alanine aminotransferase, gastrointestinal reactions, and zinc deficiency. If arthralgia symptoms do not improve after dose reduction of deferiphenone and the use of nonsteroidal anti-inflammatory drugs (NSAIDs), the drug should be discontinued. A serious adverse reaction is granulocytopenia (<1.5 × 10⁻⁶ granulocytes). 9 / L) and agranulocytosis (<0.5×10 9 (L), it is recommended to have a complete blood count once a week. If granulocytopenia occurs, discontinue use; if agranulocytosis occurs, discontinue use altogether.

[0008] Deferrasirox dispersible tablets are a novel trivalent iron chelating agent. The main component is deferasirox, chemically named 4-[3,5-di(2-hydroxyphenyl)-1,2,4-triazol-1-yl]benzoic acid, with the following structural formula: .

[0009] Deferrasirox has a high absorption rate after oral administration, with a metabolic half-life of 8-16 hours. It can cause gastrointestinal reactions, skin rash, elevated alanine aminotransferase levels, and occasionally hearing loss. Deferrasirox can also cause elevated creatinine levels; serum creatinine should be monitored monthly after starting treatment with deferasirox. It is contraindicated in patients with a creatinine clearance rate <40 mL / min.

[0010] To address the safety, efficacy, and convenience of medication for patients, the development of a novel, oral, low-dose iron chelating agent to alleviate iron overload caused by repeated blood transfusions in patients with erythrocyte disorders has become an urgent clinical need.

[0011] CN120441581A discloses a method for preparing and using a benzofuran[2,3-b]pyridine derivative targeting nuclear receptor coactivator 4 (NCOA4), the derivative having the following general structural formula.

[0012] Where R 1 ,R 2 ,R 3 The substituents can be combined arbitrarily. These compounds interfere with ferrophagy by binding to NCOA4 and effectively inhibit ferroptosis induced by RSL3 or Erastin in various cells.

[0013] CN120423991A discloses a β-selenopropionamide compound or a pharmaceutically acceptable salt thereof or an isomer thereof, a synthetic method thereof, and its application in the preparation of drugs for treating or preventing ferroptosis-related diseases. Selenopropionamide compounds have the structure shown in the following formula:

[0014] In the formula, R1 and R5 are independently any one of substituted or unsubstituted alkyl, cycloalkyl, aryl, or heteroaryl groups; R2, R3, and R4 are independently hydrogen atoms or alkyl groups. This invention discloses for the first time a novel structural type of β-selenopropionamide compounds. By simultaneously introducing diverse substituents (including alkyl, aryl, benzyl, etc.) onto the N atom and selenium atom of the amide, a dual-substituent N-aryl / alkyl-3-(selenoaryl / alkyl)propionamide skeleton with double substitution characteristics is successfully constructed, providing a novel class of iron chelating agents.

[0015] CN119552173A discloses an iron ion support, its preparation method, and its uses. The iron ion support and / or its pharmaceutically acceptable salts, solvates, or precursors have the structure shown in the following formula: , In the formula, Q represents absence or O; R1 and R2 are each independently hydrogen, substituted or unsubstituted C1-6 alkyl, or substituted or unsubstituted C3-6 cycloalkyl; R3 and R4 are each independently N, O, S, -NH2, -NH-, -OH, or -SH; R5 is C or carbonyl; the "..." between R4 and R5 indicates that R4 and R5 are selected as connected or not connected, wherein the connection is selected as a single bond or a double bond; the "..." between R3 and R5 indicates that R3 and R5 are selected as connected or not connected, wherein the connection is selected as a single bond or a double bond. This iron ion carrier exhibits good binding activity with both ferric and ferrous ions, and has low cytotoxicity, thus reducing toxic side effects.

[0016] Although there is considerable research and development on iron chelating agents, their efficacy is generally limited. Therefore, providing a novel, oral, low-dose iron chelating agent to improve iron overload caused by repeated blood transfusions in patients with erythrocyte disorders remains extremely challenging. Summary of the Invention

[0017] The purpose of this invention is to provide an iron chelating agent, its preparation method, and its application in the preparation of drugs that improve iron overload.

[0018] In a first aspect, the present invention provides an iron chelating agent that is a compound of formula (I), its stereoisomer, its tautomer, its crystalline hydrate, its solvate, its prodrug, or a pharmaceutically acceptable salt thereof. Formula (I) In the formula, R is a substituted or unsubstituted phenyl group or a substituted or unsubstituted furanyl group, wherein the substituent of the phenyl group is an alkyl or alkoxy group, and the substituent of the furanyl group is an alkyl group; R1 is H or a halogen; R2 is H, a carboxyl group, or a trihalomethyl group; R3 is H, a carboxyl group, or a carboxylic acid ester.

[0019] In some specific embodiments, R is a substituted or unsubstituted phenyl group, the substituent of the phenyl group is an alkyl or alkoxy group, R1 is H or a halogen, R2 is H or a trihalomethyl group, and R3 is a carboxyl group.

[0020] In some specific embodiments, R is a substituted or unsubstituted phenyl group, the substituent of the phenyl group is an alkyl or alkoxy group, R1 is H, fluorine, chlorine, bromine or iodine, R2 is H, trifluoromethyl, trichloromethyl, tribromomethyl or triiodomethyl, and R3 is a carboxyl group.

[0021] In some specific embodiments, R is a substituted or unsubstituted phenyl group, the substituent of the phenyl group is an alkyl or alkoxy group, R1 is H, R2 is a carboxyl or trihalomethyl group, and R3 is H or a carboxyl group.

[0022] In some specific embodiments, R is a substituted or unsubstituted phenyl group, the substituent of the phenyl group is an alkyl or alkoxy group, R1 is H, R2 is a carboxyl group, trifluoromethyl group, trichloromethyl group, tribromomethyl group, or triiodomethyl group, and R3 is H or a carboxyl group.

[0023] In some specific embodiments, the phenyl substituent is C1-C12 alkyl; preferably C1-C8 alkyl; more preferably C1-C6 alkyl; and even more preferably C1-C4 alkyl.

[0024] In some specific embodiments, the substituent of the phenyl group is C1-C12 alkoxy; preferably C1-C8 alkoxy; more preferably C1-C6 alkoxy; and even more preferably C1-C4 alkoxy.

[0025] In some specific embodiments, the substituent of the furanyl group is C1-C12 alkyl; preferably C1-C8 alkyl; more preferably C1-C6 alkyl; even more preferably C1-C4 alkyl; and even more preferably C1-C2 alkyl.

[0026] In some specific embodiments, the compound is selected from the following structures: , , , , , , , , , , , , , , .

[0027] In some specific embodiments, the compound is selected from the following structures: , , .

[0028] In some specific embodiments, the compound is selected from the following structures: , , .

[0029] In some specific embodiments, the compound is selected from the following structures: .

[0030] In a second aspect, the present invention provides a method for preparing the above-mentioned compound, comprising the following steps: subjecting aromatic compound CORE-X and heterocyclic compound CORE-n to a diazotization-coupling reaction and post-treatment to obtain the compound;

[0031] In the formula, R, R1, R2 and R3 have the same definition as above, X is a letter of A, B, C, D, E, F, G, H or I, and n is an integer from 1 to 15.

[0032] In some embodiments, the diazotization-coupling reaction is as follows: the aromatic compound CORE-X undergoes a diazotization reaction with sodium nitrite in a solvent, and then undergoes a coupling reaction with the heterocyclic compound CORE-n and an alcohol under an alkaline environment.

[0033] Preferably, the alcohol is a C1-C6 alcohol, and more preferably at least one of methanol, ethanol, propanol and butanol.

[0034] Preferably, the diazotization reaction is carried out at a temperature of 0-5℃ for 0.5-10 hours.

[0035] More preferably, the diazotization reaction is as follows: CORE-X is dissolved in a solvent, cooled to 0-5°C, and sodium nitrite aqueous solution is added dropwise, and the reaction is carried out at 0-5°C for 0.5-10 hours.

[0036] More preferably, the solvent is 0.5-10N hydrochloric acid.

[0037] More preferably, the solvent further includes a co-solvent to increase the solubility of the aromatic compound CORE-X, wherein the co-solvent is selected from at least one of acetonitrile, dichloromethane, ethanol, methanol, isopropanol, and n-propanol.

[0038] Preferably, the coupling reaction is carried out at room temperature for 6-24 hours; more preferably, it is carried out for 12-24 hours.

[0039] Preferably, the alkaline environment has a pH of 8-12; more preferably, it has a pH of 8-10.

[0040] In some implementations, the post-processing includes extraction, washing, drying with anhydrous sodium sulfate, filtration, and drying.

[0041] Preferably, the extraction is performed by adjusting the pH to 1-5 and extracting with an organic solvent; more preferably, the pH is 2-3 and the organic solvent is ethyl acetate and / or dichloromethane.

[0042] Preferably, the washing is performed using saturated saline solution.

[0043] In some embodiments, the preparation method further includes a hydrolysis step after post-treatment, specifically: the post-treated product is hydrolyzed with alkali in methanol solvent, extracted, and the organic phase is washed, dried with anhydrous sodium sulfate, filtered, and dried.

[0044] Preferably, the alkali is selected from at least one of lithium hydroxide, potassium hydroxide, and sodium hydroxide.

[0045] Preferably, the hydrolysis is carried out at 40-100℃ for 6-24 hours; more preferably, it is carried out at 40-60℃ for 12-24 hours.

[0046] Preferably, the extraction is performed by adjusting the pH to 1-5 and extracting with ethyl acetate; more preferably, the pH value is 2-3.

[0047] In some embodiments, the method for preparing the aromatic compound CORE-X includes the following steps: (i) 2-Bromo-4-fluoro-6-nitrophenol, a base and BnBr undergo an etherification reaction to give compound II; (ii) The organoboron compound and compound II react in the presence of a palladium catalyst and sodium carbonate to give an intermediate compound; (iii) The intermediate compound and hydrogen react in the presence of a hydrogenation catalyst to obtain the aromatic compound CORE-X.

[0048] Preferably, the structure of compound II in step (i) is as follows: .

[0049] Preferably, the molar ratio of 2-bromo-4-fluoro-6-nitrophenol, base and BnBr in step (i) is 1:1.2-1.8:1.2-1.8; more preferably 1:1.4-1.6:1.4-1.6.

[0050] Preferably, the base in step (i) is selected from at least one of potassium carbonate, potassium hydroxide and sodium hydroxide.

[0051] Preferably, the solvent for the etherification reaction in step (i) is at least one of acetonitrile, isopropanol, tetrahydrofuran, and dioxane.

[0052] Preferably, the etherification reaction in step (i) is carried out at room temperature for 2-12 hours; more preferably, for 2-6 hours.

[0053] Preferably, the structure of the organoboron compound in step (ii) is as follows: In the formula, R has the same definition as described above.

[0054] Preferably, the structure of the intermediate compound in step (ii) is as follows: In the formula, R has the same definition as described above.

[0055] Preferably, the solvent for the reaction in step (ii) is at least one of dioxane, tetrahydrofuran, and acetonitrile, or a mixture of at least one of the above and water.

[0056] Preferably, the molar ratio of the organoboron compound and compound II in step (ii) is 1.2-2.0:1; more preferably 1.4-1.6:1.

[0057] Preferably, the molar ratio of the organoboron compound, palladium catalyst, and sodium carbonate in step (ii) is 1:0.01-0.1:1.2-5; more preferably, it is 1:0.01-0.02:1.2-2. Preferably, the reaction in step (ii) is carried out at 70-90°C under nitrogen protection for 6-24 hours; more preferably, it is carried out at 80°C under nitrogen protection for 12-24 hours.

[0058] Preferably, the hydrogenation catalyst in step (iii) is at least one of palladium-on-carbon catalyst, platinum-based catalyst, nickel-based catalyst, ruthenium-based catalyst, and rhodium-based catalyst.

[0059] Preferably, the reaction in step (iii) is carried out at room temperature for 6-12 hours; more preferably, it is carried out for 6-10 hours.

[0060] In some embodiments, the method for preparing the heterocyclic compound CORE-n includes the following steps: (I) Aromatic primary amine compounds react with sodium nitrite, and after the reaction, hydrochloric acid solution containing tin chloride is added and filtered to obtain aromatic hydrazine compounds; (II) Aromatic hydrazine compounds and β-keto esters undergo a cyclization reaction in the presence of acetic acid, sodium acetate, and ethyl acetoacetate to obtain the heterocyclic compound CORE-n.

[0061] Preferably, the structure of the aromatic primary amine compound in step (I) is as follows: In the formula, R1, R2 and R3 have the same definitions as above.

[0062] Preferably, the molar ratio of the aromatic primary amine compound and sodium nitrite in step (I) is 1:1-1.5; more preferably, it is 1:1.1-1.2.

[0063] Preferably, the reaction in step (I) is carried out at 0-5°C for 0.5-6 hours; more preferably, it is carried out at 0-5°C for 0.5-2 hours.

[0064] Preferably, the molar ratio of the aromatic primary amine compound and tin chloride in step (I) is 1:2-5; more preferably 1:2-3.

[0065] Preferably, the structure of the aromatic hydrazine compound in step (II) is as follows: In the formula, R1, R2 and R3 have the same definitions as above.

[0066] Preferably, the molar ratio of the aromatic hydrazine compound, ethyl acetate and ethyl acetoacetate in step (II) is 1.1:0.9-1.1:0.9-1.1; more preferably, it is 1.1:1:1.

[0067] Preferably, the reaction in step (II) is carried out at room temperature for 0.5-6 hours; more preferably, it is carried out at room temperature for 0.5-2 hours.

[0068] Thirdly, the present invention provides a pharmaceutical composition comprising the above-mentioned compound, its stereoisomer, its tautomer, its crystalline hydrate, its solvate, its prodrug, or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable excipient.

[0069] The pharmaceutical compositions of this invention can be administered via any suitable route or method, such as oral or parenteral (e.g., intravenous). For oral administration, the pharmaceutical compositions of this invention are generally provided in the form of tablets, capsules, or solutions. Tablets may comprise the compounds of this invention, their stereoisomers, their tautomers, their crystalline hydrates, their solvates, their prodrugs, or pharmaceutically acceptable salts thereof, and pharmaceutically acceptable excipients. These excipients include, but are not limited to, diluents, disintegrants, binders, lubricants, colorants, or preservatives. Capsules include hard capsules and soft capsules.

[0070] For parenteral administration, the pharmaceutical compositions of the present invention can be administered via intravenous, intramuscular, or subcutaneous injection. They are typically provided as sterile aqueous solutions, suspensions, or lyophilized powders, adjusted to a suitable pH and isotonicity.

[0071] Fourthly, the present invention provides the use of the above-mentioned compounds, their stereoisomers, their tautomers, their crystalline hydrates, their solvates, their prodrugs, their pharmaceutically acceptable salts, or the above-mentioned pharmaceutical compositions in the preparation of a medicament for improving iron overload.

[0072] In some embodiments, the present invention also provides a method for improving iron overload, comprising administering to an individual in need the aforementioned compound, its stereoisomer, its tautomer, its crystalline hydrate, its solvate, its prodrug, or a pharmaceutically acceptable salt thereof, or the aforementioned pharmaceutical composition.

[0073] Fourthly, the present invention provides the use of the above-mentioned compounds, their stereoisomers, their tautomers, their crystalline hydrates, their solvates, their prodrugs, their pharmaceutically acceptable salts, or the above-mentioned pharmaceutical compositions in the preparation of medicaments for the prevention or adjunctive treatment of iron overload-related diseases.

[0074] In some embodiments, the present invention also provides a method for preventing or adjunctive treatment of iron overload-related diseases, comprising administering to an individual in need the aforementioned compound, its stereoisomer, its tautomer, its crystalline hydrate, its solvate, its prodrug, or a pharmaceutically acceptable salt thereof, or the aforementioned pharmaceutical composition.

[0075] In some implementations, the iron overload-related diseases are selected from hereditary hemochromatosis, thalassemia, aplastic anemia, pure red cell aplasia, paroxysmal nocturnal hemoglobinuria, primary myelofibrosis, congenital bone marrow failure diseases, neurodegenerative diseases, liver diseases, heart diseases, vascular diseases, or endocrine diseases.

[0076] In some embodiments, the congenital bone marrow failure disorder is selected from Fanconianemia, Dyskeratosis congenita, Diamond-Blackfan anemia, Shwachman-Diamondsyndrome, and Amegakaryocytic thrombocytopenia.

[0077] In some embodiments, the neurodegenerative disease is selected from Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), multiple sclerosis (MS), and Friedreich's ataxia (FA).

[0078] In some implementations, the liver disease is selected from alcoholic liver disease, non-alcoholic fatty liver disease, cirrhosis, or liver cancer.

[0079] In some implementations, the heart disease is selected from cardiomyopathy or heart failure.

[0080] In some implementations, the vascular disease is selected from atherosclerosis, coronary heart disease, hypertension, peripheral artery disease, or venous thromboembolism.

[0081] In some implementations, the endocrine disorder is selected from diabetes mellitus, hypothyroidism, hypogonadism, growth retardation in children, or adrenal insufficiency.

[0082] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The iron chelating agent of the present invention has the effect of scavenging iron ions in both types of cells, providing technical support for the development of novel iron chelating agent drugs.

[0083] (2) The iron chelating agent of the present invention is an oral preparation with a low effective dose, which provides technical support for improving the clinical application of iron overload caused by repeated blood transfusions in patients with erythrocyte diseases.

[0084] (3) Experiments showed that compounds 6, 14, and 12 exhibited excellent iron removal effects in HuH-7 cells, significantly higher than the two positive control drugs. In H9c2 cells, compounds 4, 10, and 14 exhibited excellent iron removal effects, significantly higher than the two positive control drugs. Detailed Implementation

[0085] The features mentioned above, or the features mentioned in the embodiments, of this invention can be combined arbitrarily. All features explained in this specification can be used with any methodological form, and each feature disclosed in the specification can be replaced by any alternative feature that provides the same, equivalent, or similar purpose. Therefore, unless otherwise specified, the disclosed features are merely general examples of equivalent or similar features.

[0086] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. The following embodiments are implementation methods to indicate specific conditions, generally according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all percentages and fractions are by weight.

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those well known to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0088] All ranges relating to the same component or property include endpoints that can be combined independently. Because these ranges are continuous, they encompass every numerical value between the minimum and maximum value. It should also be understood that any numerical range referenced in this invention is intended to include all subranges within that range.

[0089] Terminology Definition Unless otherwise stated, the following terms and phrases as used herein have the following meanings.

[0090] All numerical values ​​or expressions relating to component amounts, process conditions, etc., used in this invention shall be understood to be modified by the word "about" in all cases. When referring to a quantity or range of values, the quantity or range is an approximation within experimental variability (or within statistical experimental error). In this invention, the term "about" shall have the meaning of being within 10%, preferably within 5%, of the specified value or range.

[0091] In this invention, "room temperature" refers to ambient temperature, ranging from about 10°C to about 40°C. In some embodiments, "room temperature" refers to a temperature ranging from about 20°C to about 30°C; in other embodiments, "room temperature" refers to a temperature ranging from about 25°C to about 30°C; and in still other embodiments, "room temperature" refers to 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc.

[0092] "Alkyl" is a hydrocarbon containing a positive carbon atom, a secondary carbon atom, a tertiary carbon atom, or a cyclic carbon atom. For example, an alkyl group can have 1 to 12 carbon atoms (i.e., C1-C12 alkyl), 1 to 10 carbon atoms (i.e., C1-C10 alkyl), 1 to 8 carbon atoms (i.e., C1-C8 alkyl), 1 to 6 carbon atoms (i.e., C1-C6 alkyl), or 1 to 4 carbon atoms (i.e., C1-C4 alkyl). Examples of suitable alkyl groups include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (i-Pr, i-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), and 2-butyl (s-Bu, s-butyl, -CH (CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl ( -CH2CH2CH(CH3)2), 2-methyl-1-butyl(-CH2CH(CH3)CH2CH3), 1-hexyl(-CH2CH2CH2CH2CH2CH3), 2-hexyl(-CH(CH3)CH2CH2CH2CH3), 3-hexyl(-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl(-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl(-CH(CH3)CH (CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3 and octyl (-(CH2)7CH3).

[0093] An "alkoxy group" is a substituent formed by removing a hydrogen atom from a carbon atom in an alkane molecule and then connecting it with an oxygen atom (-O-). For example, an alkoxy group can have 1 to 12 carbon atoms (i.e., C1-C12 alkoxy), 1 to 10 carbon atoms (i.e., C1-C10 alkoxy), 1 to 8 carbon atoms (i.e., C1-C8 alkoxy), 1 to 6 carbon atoms (i.e., C1-C6 alkoxy), or 1 to 4 carbon atoms (i.e., C1-C4 alkoxy). Examples of suitable alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, 1-methylethoxy, butoxy, 1-methylpropoxy, 2-methylpropoxy, 1,1-dimethylethoxy, pentooxy, 1-methylbutoxy, 2-methylbutoxy, 3-methoxybutoxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy, 2,2-dimethylpropoxy, 1-ethylpropoxy, hexoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-ethyl-1-methylpropoxy, and 1-ethyl-2-methylpropoxy.

[0094] Halogens are represented by fluorine (F), chlorine (Cl), bromine (Br), or iodine (I) atoms.

[0095] The term "substituent," such as "the phenyl group is substituented as a C1-C12 alkyl" or "the phenyl group is substituented as a C1-C12 alkoxy," respectively refers to a C1-C12 alkyl or C1-C12 alkoxy group in which one or more hydrogen atoms of the phenyl group are independently replaced by non-hydrogen substituents. Unless otherwise stated, when the term "substituent" is used in conjunction with a group having two or more substituted moieties, such as a phenylalkyl group, the substituent may be attached to the phenyl moiety, the alkyl moiety, or both.

[0096] The term "pharmaceutically acceptable" means that a carrier, delivery substance, excipient, diluent, and / or the salt formed therefrom is generally chemically or irrationally compatible with other components constituting a drug dosage form and physiologically compatible with receptors.

[0097] The term "pharmaceuticalally acceptable excipient" refers to carriers that do not cause significant irritation to the body and do not impair the biological activity and properties of the active compound. This includes, but is not limited to, any diluents, disintegrants, binders, glidants, and wetting agents commonly used in the art for human or animal use.

[0098] The term "pharmaceutically acceptable salt" refers to a salt that retains the biological potency of the free acid or base of a particular compound without any adverse biological effects. Examples include acid (including organic and inorganic acids) addition salts or base addition salts (including organic and inorganic bases), as well as zwitterionic salts and quaternary ammonium salts, such as alkylammonium salts. The pharmaceutically acceptable salts of the present invention can be synthesized from parent compounds containing an acid radical or base using conventional chemical methods. Generally, such salts are prepared by reacting these compounds in their free acid or base form with a stoichiometric amount of a suitable base or acid in water or an organic solvent or a mixture of both.

[0099] The term "prodrug fraction" refers to the unstable functional group that is isolated from an active inhibitory compound during metabolism, systemically or intracellularly, through hydrolysis, enzymatic cleavage, or other processes (Bundgaard, Hans, "Design and Application of Prodrugs" in Textbook of Drug Design and Development (1991), P. Krogsgaard-Larsen and H. Bundgaard, Eds. Harwood Academic Publishers, pp. 113-191). Prodrug fractions can be used to enhance solubility, absorption, and lipophilicity to optimize drug delivery, bioavailability, and efficacy. Prodrug fractions may include active metabolites or the drug itself.

[0100] Compounds of Formula I or their pharmaceutically acceptable salts may exist as different polymorphs or pseudopolymorphs. Crystal polymorphism, as used herein, refers to the ability of a crystalline compound to exist in different crystal structures. Crystal polymorphism can originate from differences in crystal packing (packing polymorphism) or differences in packing between different conformational isomers of the same molecule (conformational polymorphism). Pseudopolymorphism, as used herein, refers to the ability of a compound's hydrates or solvates to exist in different crystal structures. The pseudopolymorphs of this invention may exist due to differences in crystal packing (packing pseudopolymorphism) or due to differences in packing between different conformational isomers of the same molecule (conformational pseudopolymorphism). This invention comprises all polymorphs and pseudopolymorphs of compounds of Formula I and their pharmaceutically acceptable salts.

[0101] Compounds of Formula I or their pharmaceutically acceptable salts can also exist as amorphous solids. The amorphous solids used herein are solids in which the positions of atoms do not exhibit long-range order. This definition also applies when the crystal size is 2 nanometers or less. The amorphous forms of the present invention can be established using additives, including solvents. The present invention encompasses all amorphous forms of compounds of Formula I and their pharmaceutically acceptable salts.

[0102] The term "pharmaceutical composition" means a composition comprising the compound described in this disclosure or its stereoisomers, tautomers, hydrates, solvates, prodrugs, pharmaceutically acceptable salts, and at least one pharmaceutically acceptable component selected from the following, depending on the manner of administration and dosage form: including, but not limited to, carriers, diluents, adjuvants, excipients, preservatives, fillers, disintegrants, wetting agents, emulsifiers, suspending agents, sweeteners, flavoring agents, fragrances, antibacterial agents, antifungal agents, lubricants, dispersants, thermosensitive materials, temperature regulators, adhesives, stabilizers, suspending agents, etc.

[0103] The “medicine” or “pharmaceutical composition” described in this invention can be prepared by any method known in pharmaceutical science. Generally, these preparation methods involve associating the compound, its stereoisomers, its tautomers, its hydrates, its solvates, its prodrugs, or its pharmaceutically acceptable salts (hereinafter referred to as the active ingredient) with a carrier and / or one or more other auxiliary components, and then, if desired and / or expected, shaping and / or packaging the product into desired single-dose or multi-dose units.

[0104] The "medicine" and "pharmaceutical composition" of this invention can be prepared according to known methods, such as those described in the general rules for preparation in the Chinese Pharmacopoeia 2020, the Japanese Pharmacopoeia 16th Edition, the United States Pharmacopoeia, and the European Pharmacopoeia 9th Edition. The specific preparation method depends on the dosage form.

[0105] The active ingredients and pharmaceutically acceptable excipients in the "medicine" or "pharmaceutical composition" described in this invention will vary depending on the identity, body type, and / or condition of the treated subject and further on the route of administration of the active ingredient. The medicine or pharmaceutical composition may contain between 0.1% and 100% (w / w) of the active ingredient.

[0106] As used herein, “treatment” means, unless otherwise stated, reversing or alleviating the condition or disease to which the term applies, or one or more symptoms of such condition or disease, inhibiting the progression of said condition or disease or one or more symptoms thereof, or preventing said condition or disease or one or more symptoms thereof. As used in this invention, the term “treatment” refers to a therapeutic act, as defined above.

[0107] The term "effective dose" or "therapeutic effective dose" refers to a sufficient amount of a drug or pharmaceutical composition that is non-toxic but achieves the desired effect. The precise dosage will vary depending on a variety of factors, such as subject-dependent variables (e.g., age, immune system health, etc.), the disease or illness, and the treatment administered.

[0108] The pharmaceuticals or pharmaceutical compositions of the present invention can be administered orally, topically, parenterally, or mucosally (e.g., sublingually, by inhalation, or rectally) in dosage units comprising conventional, non-toxic, pharmaceutically acceptable carriers. Oral administration is generally preferred. The active agent can be administered orally in capsule, tablet, or other similar forms.

[0109] The pharmaceutical or pharmaceutical composition of the present invention can be delivered parenterally, i.e., administered intravenously (IV), intraventricularly (ICV), subcutaneously (SC), intraperitoneally (IP), intramuscularly (IM), subcutaneously (SD), or intradermally (ID), by direct injection, for example, by rapid concentration or continuous infusion. Formulations for injection can be presented in unit dosage forms, such as in ampoules or multi-dose containers with added preservatives. The composition can be in the form of an excipient, a suspension, solution, or emulsion in an oil or aqueous carrier, and may contain formulation agents such as anti-settling agents, stabilizers, and / or dispersants. Alternatively, the active ingredient can be reconstituted in powder form with suitable excipients (e.g., sterile, pyrogen-free water) prior to use.

[0110] The medicaments or pharmaceutical compositions of the present invention can also be formulated for rectal administration, for example as suppositories or retention enemas (e.g., containing conventional suppository bases such as cocoa butter or other glycerides).

[0111] MeCN: Acetonitrile, BnBr: Benzyl bromide, Pd(PPH3)2Cl2: Palladium complex, dioxane: Dioxane, MeOH: Methanol, AcONa: Sodium acetate, AcOH: Acetic acid, EtOH: Ethanol, PE: Petroleum ether, EA: Ethyl acetate, DCM: Dichloromethane, LiOH: Lithium hydroxide, SnCl2: Stannous chloride, 1H NMR: Proton NMR, DMSO: Dimethyl sulfoxide, DMSO-d6: Deuterated dimethyl sulfoxide.

[0112] Preparation of 1-benzyloxy-2-bromo-4-fluoro-6-nitrobenzene

[0113] MeCN (1 L) was added to a 3 L three-necked flask, followed by 2-bromo-4-fluoro-6-nitrophenol (compound I, 100 g, 0.424 mol). K2CO3 (87.8 g, 0.636 mol) and BnBr (80.5 g, 0.636 mol) were added at 5-8 °C, and the mixture was then reacted under reflux for 4 h.

[0114] After filtering to remove inorganic salts, the reaction system was concentrated under reduced pressure until no acetonitrile residue remained. It was then added to EA (2 L), washed once with water (2 L), and once with saturated brine (500 mL). The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was pulped overnight in PE (300 mL), and after filtration, compound II (1-benzyloxy-2-bromo-4-fluoro-6-nitrobenzene, brown solid, 104 g, yield: 75%) was obtained.

[0115] ¹H NMR (DMSO-d6, 400MHz) δ5.02(s,2H),7.38-7.25(m,3H),7.47-7.38(m,2H),7.61-7.57 (dd,1H), 7.66-7.2 (dd,1H).

Synthesis of CORE-A

[0116] Synthesis of A2: Compound II (20 g, 61.3 mmol) and 5-methylfuran-2-boronic acid pinacol ester (denoted as A1, 19 g, 92 mol) were added to dioxane (200 mL), followed by the addition of Na2CO3 (13 g, 122.6 mmol) and H2O (40 mL), purging with nitrogen three times. Then, Pd(PPh3)2Cl2 (4.3 g, 6.1 mmol) was added, and nitrogen was purged three more times. The mixture was heated to 75-80 °C and reacted overnight. The reaction was completed by TLC (PE / EA / DCM = 40 / 1 / 1, 254 nm).

[0117] The reaction mixture was poured into H2O (800 mL), and EA (200 mL x 3) was added for extraction. After the organic phases were combined, the mixture was washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (PE - PE / EA = 20 / 1 product yield) to obtain compound A2 (20 g).

[0118] ¹H NMR(CD3OD,400MHz) δ2.4(s,3H,C13-H),5.0(s,2H,C24H),6.2(s,1H,C10-H),6.9(s,1H,C9-H),7. 3-7.5(m,6H,C4-H,C19-H,C20-H,C21-H,C22-H,C23-H),7.7-7.8(d,1H,C6-H). Synthesis of CORE-A: Compound A220g (60mmol) was added to 400mL of MeOH, and nitrogen was purged three times. Then, 2g of Pd / C (5%w / w) was added to purge hydrogen three times, and the reaction was carried out at room temperature under hydrogen conditions for 8 h. The reaction was stopped by TLC (PE / EA = 1 / 1, 254nm).

[0119] The reaction system was filtered through diatomaceous earth, and palladium on carbon was washed with methanol (50 mL X 2). The filtrates were concentrated in batches to obtain compound CORE-A (12 g, yield 94.8%).

[0120] ¹H NMR(DMSO-d6,400MHz),δ2.31(s,3H,C15-H),5.18(s,2H,,N1-H),6.16-6.17(d, 1H,C12-H),6.33-636(dd,1H,C5-H),6.54-657(dd,1H,C7-H),6.86-6.87(d,1H,C11-H),8.90(s,1H,O9-H).

Synthesis of CORE-B

[0121] Synthesis of B2: Compound II (20 g, 61.3 mmol) and pinacol 4-tert-butylphenylborate (denoted as B1, 23.9 g, 92 mmol) were added to dioxane (250 mL), followed by the addition of Na₂CO₃ (15.9 g, 150 mmol) and H₂O (40 mL), purging with nitrogen three times. Then, Pd(PPh₃)₂Cl₂ (4.3 g, 6.1 mmol) was added, and nitrogen was purged three more times. The mixture was heated to 75-80 °C and reacted overnight. The reaction was completed by TLC (PE / EA / DCM = 40 / 1 / 1, 254 nm).

[0122] The reaction mixture was poured into H2O (800 mL), extracted three times with EA (200 mL x 3), and the organic phases were combined. The mixture was washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (PE - PE / EA = 20 / 1 product yield) to give compound B2 (18.85 g).

[0123] ¹H NMR(CD3OD,400MHz)δ1.40(s,9H,C15-H,C16-H,C17-H), 4.57(s,2H,C28-H),6.99-7.02(dd,2H,C23-H,C27-H),7.22-7.49(m,9H,C4-H,C6-H,C9-H,C10-H,C12-H,C13-H,C24-H,C25-H,C26-H). CORE-B Synthesis: 18.85 g (50 mmol) of compound B2 was added to MeOH (360 mL), and nitrogen was purged three times. Then, Pd / C2 g (5% w / w) was added to purge hydrogen three times, and the reaction was carried out at room temperature under hydrogen conditions for 8 h. The reaction was stopped by TLC (PE / EA = 1 / 1, 254 nm).

[0124] The reaction system was filtered through diatomaceous earth, and palladium on carbon was washed with methanol (50 mL x 2). The filtrates were concentrated in batches to obtain compound CORE-B (12 g, yield 93.2%).

[0125] ¹H NMR (DMSO-d6,400MHz)δ1.38(s,9H,C17-H,C18-H,C19-H),5.10(s,2H,N1-H),6.17-6.19(dd,1H, C5),6.36-6.38(dd,1H,C7),7.22-7.49(m,4H,C11-H,C12-H,C14-H,C15-H),7.9(s,1H,O9-H).

CORE-C Synthesis

[0126] Synthesis of C2: Compound II (20 g, 61.3 mmol) and pinacol 4-methylphenylborate (C1, 20 g, 92 mol) were added to dioxane (200 mL), followed by the addition of Na2CO3 (13 g, 122.6 mmol) and H2O (40 mL), purging with nitrogen three times. Then, Pd(PPh3)2Cl2 (4.3 g, 6.1 mmol) was added, purging with nitrogen three more times, and the mixture was heated to 75-80 °C and reacted overnight. The reaction was completed by TLC (PE / EA / DCM = 40 / 1 / 1, 254 nm).

[0127] The reaction mixture was poured into H2O (800 mL), extracted three times with EA (200 mL x 3), and the organic phases were combined. The mixture was washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (PE - PE / EA = 20 / 1 product yield) to give compound C2 (16 g).

[0128] ¹H NMR(CD3OD,400MHz)δ2.45(s,3H,C14-H),4.58(s,2H,C25-H),7.08-7.10(dd,2H ,C20-H,C24-H),7.26-7.49(m,9H,C4-H,C6-H,C9-H,C10-H,C12-H,C13-H,C21-H, C22-H,C23-H). CORE-C synthesis: 16 g (40 mmol) of compound C2 was added to MeOH (320 mL), and nitrogen gas was purged three times. Then, 1.5 g (5% w / w) of Pd / C was added to purge hydrogen gas three times. The reaction was then carried out at room temperature under hydrogen gas for 8 h. The reaction was stopped by TLC (PE / EA = 1 / 1, 254 nm).

[0129] The reaction system was filtered through diatomaceous earth, and palladium on carbon was washed with methanol (50 mL X 2). The filtrates were concentrated in batches to obtain compound CORE-C (10.3 g, 100% yield).

[0130] ¹H NMR(DMSO-d6,400MHz)δ2.45(s,3H,C16-H),5.20(s,2H,N1-H),6.19-6.21(dd,1H,C5-H),6 .38-6.42(dd,1H,C7-H),7.28-7.49(m,4H,C11-H,C12-H,C14-H,C15-H),7.8(s,1H,O9-H).

CORE-D Synthesis

[0131] The reaction mixture was poured into H2O (800 mL), extracted three times with EA (200 mL x 3), and the organic phases were combined. The mixture was washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (PE - PE / EA = 20 / 1 product yield) to obtain compound D2 (17.3 g).

[0132] ¹H NMR(CD3OD,400MHz)δ2.18(s,3H,C25-H),4.49-4.63(d,2H,C14-H),6.88-6.94(dd,2H,C20- H,C24-H),7.20-7.56(m,9H,C4-H,C6-H,C10-H,C11-H,C12-H,C13-H,C21-H,C22-H,C23-H). CORE-D synthesis: 17.3 g (51 mmol) of compound D2 was added to MeOH (340 mL), and nitrogen was purged three times. Then, 2.5 g (5% w / w) of Pd / C was added to purge hydrogen three times, and the reaction was carried out at room temperature under hydrogen conditions for 8 h. The reaction was stopped by TLC (PE / EA = 1 / 1, 254 nm).

[0133] The reaction system was filtered through diatomaceous earth, and palladium on carbon was washed with methanol (50 mL X 2). The filtrates were concentrated in batches to obtain compound CORE-D (11 g, yield 98.7%).

[0134] ¹H NMR (DMSO-d6,400MHz)δ2.18(s,3H,C16-H),5.18(s,2H,N1-H),6.26-6.28(dd,1H,C5-H),6. 33-6.35(dd,1H,C7-H),7.18-7.46(m,4H,C12-H,C13-H,C14-H,C15-H),7.9(s,1H,O9-H).

Synthesis of CORE-E

[0135] E2 synthesis: Compound II (20 g, 61.3 mmol) and 4-methoxyphenylboronic acid pinacol ester (E1, 21.5 g, 92 mmol) were added to dioxane (200 mL), followed by the addition of Na₂CO₃ (13 g, 122.6 mmol) and H₂O (40 mL), purging with nitrogen three times. Then, Pd(PPh₃)₂Cl₂ (4.3 g, 6.1 mmol) was added, and nitrogen was purged three more times. The mixture was heated to 80 °C and reacted overnight. The reaction was completed by TLC (PE / EA / DCM = 40 / 1 / 1, 254 nm).

[0136] The reaction mixture was poured into H2O (800 mL), extracted three times with EA (200 mL x 3), and the organic phases were combined. The mixture was washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (PE - PE / EA = 20 / 1 product yield) to obtain compound E2 (18 g).

[0137] ¹H NMR(CD3OD,400MHz)δ3.9(s,3H,C15-H),4.6(s,2H,C26-H),7.0(d,2H,C10-H,C12-H),7.1(dd, 2H,C21-H,C25-H),7.2-7.4(m,5H,C4-H,C6-H,C22-H,C23-H,C24-H),7.5(d,2H,C9-H,C13-H). Synthesis of CORE-E: 18 g (50 mmol) of compound E2 was added to MeOH (360 mL), and nitrogen was purged three times. Then, 2.8 g (5% w / w) of Pd / C was added to purge hydrogen three times, and the reaction was carried out at room temperature under hydrogen conditions for 8 h. The reaction was stopped by TLC (PE / EA = 1 / 1, 254 nm).

[0138] The reaction system was filtered through diatomaceous earth, and palladium on carbon was washed with methanol (50 mL X 2). The filtrates were concentrated in batches to obtain compound CORE-E (11.2 g, yield 95.3%).

[0139] ¹H NMR(DMSO-d6,400MHz)δ3.78(s,3H,C17-H),5.04(s,2H,N1-H),6.17-6.20(dd,1H,C5-H),6.37-6.41 (dd,1H,C7-H),6.94-6.97(d,2H,C12-H,C14-H),7.43-7.45(d,2H,C11-H,C15-H),7.71(s,1H,O9-H). Using the above method, CORE-F, CORE-G, CORE-H, CORE-I, etc. can be easily prepared.

[0140]

Synthesis of CORE-1

[0141] Methyl 3-fluoro-4-aminobenzoate (compound 1-1, 20 g, 118 mmol) was added to conc.HCl (120 mL), and the temperature was lowered to 0-5 °C. At 0 °C, NaNO2 aqueous solution (9 g, 90 mL H2O) was added dropwise over 15 min. After the addition was complete, the system gradually dissolved. The reaction system was maintained at 0-5 °C for 0.5 h. After TLC analysis (PE / EA = 5 / 1) showed no remaining raw material, the temperature was controlled at 0 °C, and SnCl2 (56 g) in conc.HCl (150 mL) solution was added dropwise to the reaction system. A large amount of solid precipitated with the addition. After the addition was complete, the mixture was filtered, and the filter cake was collected.

[0142] After dissolving the filter cake in a large amount of MeOH (1L), the inorganic salts were removed by filtration. The solution was concentrated under reduced pressure to a volume of approximately 100 mL of methanol. After adding approximately 300 mL of EA, the solution was filtered, the filter cake was collected, and dried to obtain the target product compound 1-2 (20.4 g, yield 78%).

[0143] 1 H NMR(DMSO-d6,400MHz)δ3.70-3.80(s,3H,C12-H),4.20-4.30(s,2H,N1-H),7.10-7.20( m,1H,C4-H),7.42-7.52(d,1H,C7-H),7.55-7.60(s,1H,N2-H),7.55-7.60(m,1H,C5-H). Compounds 1-2 (17.17 g, 93.2 mmol) were added to acetic acid (172 mL), followed by AcONa (6.95 g, 84.8 mmol), and then ethyl acetoacetate (11 g, 84.8 mmol). The reaction was carried out at 5 °C for 1 h. TLC analysis (PE / EA = 5 / 1, 254 nm) showed the reaction was complete. After adjusting the pH to 9 with 10% NaOH aqueous solution, the mixture was extracted with EA (500 mL x 2). The organic phases were combined, washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the intermediate compound (20 g).

[0144] The crude compound (20 g, 67.3 mmol) was dissolved in EtOH (200 mL), and NaOH (5.4 g) solid was added. After reacting at room temperature for 30 min, a sample was taken for analysis (PE / EA = 1 / 1, 254 nm), indicating that the reaction was complete. The reaction system was concentrated under reduced pressure to remove ethanol, yielding the crude product. The crude product was dissolved in DCM / MeOH = 3 / 1 (500 mL), and filtered through diatomaceous earth to remove the salts generated in the reaction. The filtrate was collected and concentrated under reduced pressure to obtain a yellow solid (14.5 g). This solid was then dissolved in DCM / MeOH = 10 / 1 (500 mL), sonicated for 20 min, filtered, and the mother liquor was collected. The mother liquor was concentrated under reduced pressure and filtered to obtain compound CORE-1 (12 g, yellow solid, yield 51.5%).

[0145] ¹HNMR(DMSO-d6,400MHz)δ2.20(s,3H,C11-H),3.42(s,2H,C16-H),3.92(s,3H,C18-H),7.54-7.89(m,3H,C6-H,C8-H,C9-H).

Synthesis of CORE-2

[0146] Methyl 4-amino-2-trifluoromethylbenzoate (denoted as 2-1, 25 g, 114 mmol) was added to conc.HCl (150 mL), and the temperature was lowered to 0-5 °C. At 0 °C, NaNO2 aqueous solution (8.7 g, 50 mL H2O) was added dropwise over 15 min. After the addition was complete, the system gradually dissolved. The reaction system was maintained at 0-5 °C for 2 h. After TLC analysis (PE / EA = 5 / 2) showed no remaining raw material, the temperature was controlled at 0 °C, and SnCl2 (54 g) in conc.HCl (150 mL) solution was added dropwise to the reaction system. A large amount of solid precipitated with the addition. After the addition was complete, the mixture was filtered, and the filter cake was collected.

[0147] After dissolving the filter cake in a large amount of MeOH (1L), the inorganic salts were removed by filtration. The solution was concentrated under reduced pressure to 100 mL of methanol, and then 300 mL of EA was added. The solution was then filtered, the filter cake was collected, and dried to obtain the target product compound 2-2 (26.5 g, yield 99%).

[0148] ¹H NMR(DMSO-d6,400MHz),δ3.82(s,3H,C1-H),7.21-7.22(d,1H,C7-H),7.40 (s,1H,C5-H),7.87(d,1H,C8-H),9.17(s,1H,N9-H),10.45(s,2H,N10-H). Compound 2-2 (26.5 g, 113 mmol) was added to acetic acid (265 mL), followed by AcONa (8.4 g, 102 mmol), and then ethyl acetoacetate (11 g, 102 mmol). The reaction was carried out at 5 °C for 2 h. TLC analysis (PE / EA = 5 / 1, 254 nm) showed the reaction was complete. After adjusting the pH to 9 with 10% NaOH aqueous solution, the mixture was extracted with EA (500 mL x 2). The organic phases were combined, washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the intermediate compound (31.2 g).

[0149] The intermediate compound (31.2 g) was dissolved in EtOH (300 mL), and NaOH (8.2 g) solid was added. After reacting at room temperature for 60 min, a sample was taken for analysis (PE / EA = 1 / 1, 254 nm), indicating that the reaction was complete. The reaction system was concentrated under reduced pressure to remove ethanol, yielding a crude product. The crude product was dissolved in DCM / MeOH = 3 / 1 (800 mL), and filtered through diatomaceous earth to remove the salts generated in the reaction. The filtrate was collected, concentrated under reduced pressure to obtain a yellow solid (28 g), which was then dissolved in DCM / MeOH = 10 / 1 (500 mL). After sonication for 20 min, the solution was filtered, and the mother liquor was collected, concentrated under reduced pressure, and filtered to obtain compound CORE-2 (23.5 g, yellow solid, yield 69.3%).

[0150] ¹HNMR(CD3OD,400MHz)δ2.22(s,3H,C12-H),3.49(s,2H,C10-H),3.92(s,3H,C1-H),7.85(d,1H,C7-H),8.20(d,1H,C6-H),8.33(s,1H,C4-H).

Synthesis of CORE-3

[0151] Methyl 3-aminobenzoate (denoted as 3-1, 50 g, 330 mmol) was added to conc.HCl (300 mL), and the temperature was lowered to 0-5 °C. At 0 °C, NaNO2 aqueous solution (25 g, 100 mL H2O) was added dropwise over 15 min. After the addition was complete, the system gradually dissolved. The reaction system was maintained at 0-5 °C for 2 h. After TLC analysis (PE / EA = 5 / 1) showed no remaining raw material, the temperature was controlled at 0 °C, and SnCl2 (156 g) in conc.HCl (450 mL) solution was added dropwise to the reaction system. A large amount of solid precipitated with the addition. After the addition was complete, the mixture was filtered, and the filter cake was collected.

[0152] After dissolving the filter cake in a large amount of MeOH (1L), the inorganic salts were removed by filtration. The solution was concentrated under reduced pressure to 100 mL of methanol. Then, 300 mL of EA was added, and the solution was filtered. The filter cake was collected, dried, and the target product compound 3-2 (55 g, 100% yield) was obtained.

[0153] 1 H NMR(DMSO-d6,400MHz)δ3.85(s,3H,C12-H),7.23-7.26(dd,1H,C6-H),7.41-7.45(t,1H,C5-H ),7.52-7.54(dd,1H,C4-H),7.56-7.57(d,1H,C8-H),8.60(s,1H,N2-H),10.30(s,2H,N1-H). Compound 3-2 (33.2 g, 200 mmol) was added to acetic acid (330 mL), followed by AcONa (14.7 g, 180 mmol), and then ethyl acetoacetate (23.4 g, 180 mmol). The reaction was carried out at 5 °C for 1 h. TLC analysis (PE / EA = 5 / 1, 254 nm) showed the reaction was complete. After adjusting the pH to 9 with 10% NaOH aqueous solution, the mixture was extracted with EA (500 mL x 2). The organic phases were combined, washed once with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the intermediate compound (35 g).

[0154] The intermediate compound (35 g) was dissolved in EtOH (350 mL), and NaOH (15 g) solid was added. After reacting at room temperature for 2 hours, a sample was taken for analysis (PE / EA = 1 / 1, 254 nm), indicating that the reaction was complete. The reaction system was concentrated under reduced pressure to remove ethanol, yielding a crude product. The crude product was dissolved in DCM / MeOH = 3 / 1 (1000 mL), and filtered through diatomaceous earth to remove the salts generated in the reaction. The filtrate was collected and concentrated under reduced pressure to obtain a yellow solid (15.2 g). This solid was then dissolved in DCM / MeOH = 10 / 1 (500 mL), sonicated for 20 min, filtered, and the mother liquor was collected. The mother liquor was concentrated under reduced pressure and filtered to obtain compound CORE-3 (13.5 g, yield 29%).

[0155] ¹HNMR(CD3OD,400MHz)δ2.20(s,3HC14-H)3.47(s,2H,C12-H),3.91(s,3H,C1-H ),7.46(t,1H,C5-H),7.84(d,1H,C6-H),8.12(d,1H,C4-H),8.48(s,1H,C8-H). Using the above method, CORE-4, CORE-5, CORE-6, etc. can be easily produced.

[0156] Example 1: Compound 1 Synthesis of Compound 1:

[0157] Compound CORE-A (2.07 g, 10 mmol) was added to 1 N HCl (20 mL), and the solution was cooled to 0 °C. NaNO2 (7.8 g, 10 mL water) solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-1 (2.25 g, 9 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (20 mL) was added, and the reaction was slowly allowed to proceed to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) indicated the reaction was complete.

[0158] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (20 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound A1-1 (2.4 g).

[0159] 1H NMR(DMSO-d6,400MHz)δ2.33(s,3H,C23-H),2.36(s,3H,C21-H),3.87(s, 3H,C34-H),6.27-6.28(d,1H,C18-H),6.99-7.00(d,1H,C17-H),7.19-7.2 2(dd,1H,C11-H),7.35-7.38(dd,1H,C13-H),7.69-7.72(t,1H,C26-H),7. 80-7.86(m,2H,C25-H,C28-H),9.59(s,1H,NH7-H),13.45(s,1H,OH15-H). Compound A1-1 (2.4 g, 5.1 mmol) was added to MeOH (50 mL), followed by an aqueous solution of lithium hydroxide (0.72 g, 10 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis was performed on a sample (PE / EA = 3 / 1, 254 nm), indicating the reaction was complete.

[0160] After removing methanol by concentrating the reaction system under reduced pressure, 40 mL of water was added, and impurities were removed by extraction with EA. Then, the aqueous phase was adjusted to pH 2-3 with 1 NHCl, and extracted with EA (20 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product.

[0161] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 1 (1.82 g, yield 45%).

[0162]

[0163] 1 H NMR (DMSO-d6,400MHz)δ2.33(s,3H,C23-H),2.36(s,3H,C21-H),6.27-6.28(d,1H,C18-H),6.99-7.00(d,1H,C17-H),7.19-7.22(dd,1H,C11-H), 7.35-7.38(dd,Hz,1H,C13-H),7.70-7.74(t,1H,C26-H),7.84-7.90(m,2H,C25-H,C28-H),9.59(s,1H,NH7-H),13.44(s,2H,OH15-H,OH33-H). Example 2: Compound 2

[0164] Compound CORE-A (2.07 g, 10 mmol) was added to 1 N HCl (20 mL), followed by 10 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (0.78 g, 10 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-2 (2.7 g, 9 mmol) was then added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. EtOH (20 mL) was then added, and the mixture was slowly allowed to rise to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) indicated the reaction was complete.

[0165] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (20 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound A2-1 (2.45 g).

[0166] 1 H NMR(DMSO-d6,400MHz)δ2.36(s,3H,C21-H),2.37(s,3H,C23-H),3.86(s,3H,C3 3-H),6.28-6.29(d,1H,C18-H),7.00-7.01(d,1H,C17-H),7.18-7.21(dd,1H,C 11-H),7.33-7.36(dd,1H,C13-H),7.98-8.01(d,1H,C26-H),8.22-8.25(dd,1H ,C25-H),8.43-8.44(d,1H,C29-H),9.65(s,1H,NH7-H),13.53(s,1H,OH15-H). Compound A2-1 (2.45 g, 4.7 mmol) was added to MeOH (49 mL), followed by an aqueous solution of lithium hydroxide (0.67 g, 10 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed on a sample, indicating the reaction was complete.

[0167] After removing methanol by concentrating the reaction system under reduced pressure, 50 mL of water was added, and impurities were removed by extraction with EA. Then, the aqueous phase was adjusted to pH 2-3 with 1 NHCl, and allowed to stand at 0-5℃ for 5 h. The filter cake was collected by filtration to obtain the crude product.

[0168] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 2 (1.47 g, yield 61.2%).

[0169]

[0170] 1 H NMR(DMSO-d6,400MHz)δ2.36(s,3H,C21-H),2.37(s,3H,C23-H),6.28-6.29 (d,1H,C18-H),7.00-7.01(d,1H,C17-H),7.18-7.21(dd,1H,C11-H),7.33-7.36(dd,1H,C13-H),7.99-8.02(d,1H ,C26-H),8.23-8.26(dd,1H,C25-H),8.44-8.45(d,1H,C29-H),9.63(s,1H,NH7-H),13.53(s,2H,OH15-H,OH32-H). Example 3: Compound 3

[0171] Compound CORE-A (2.07 g, 10 mmol) was added to 1 N HCl (20 mL), and the solution was cooled to 0 °C. 10 mL of EtOH was added, and an aqueous solution of NaNO2 (0.78 g, 10 mL of water H2O) was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-3 (2.1 g, 9 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with a saturated Na2CO3 aqueous solution. Then, 20 mL of EtOH was added, and the solution was slowly heated to room temperature and reacted overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed, indicating the reaction was complete.

[0172] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (20 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound A3-1 (3.2 g).

[0173] ¹H NMR(DMSO-d6,400MHz)δ2.36(s,3H,C23-H),2.52(s,3H,C21-H),3.88(s,3 H,C33),6.28-6.29(d,1H,C18-H),6.92(d,1H,C17-H),7.02(dd,1H,C11-H) ,7.42(dd,1H,C13-H),7.61(t,1H,C26-H),7.78(d,1H,C27-H),8.19(dd,1 H,C25-H),8.54(d,1H,C29-H),10.79(s,1H,NH7-H),13.42(s,1H,OH15-H). Compound A3-1 (2.7 g, 6 mmol) was added to MeOH (54 mL), followed by an aqueous solution of lithium hydroxide (0.86 g, 10 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) showed the reaction was complete.

[0174] After removing methanol by concentrating the reaction system under reduced pressure, 60 mL of water was added, and impurities were removed by extraction with EA. Then, the aqueous phase was adjusted to pH 2-3 with 1 NHCl, and extracted with EA (30 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product.

[0175] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 3 (1.35 g, yield 51.7%).

[0176]

[0177] ¹H NMR (DMSO-d6,400 MHz)δ2.35(s,3H,C23-H),2.51(s,3H,C21-H),6.28-6.29(d,1H,C18-H),6.92(d,1H,C17-H),7.02(dd,1H,C11-H),7.42(dd,1H,C13-H),7.61( t,1H,C26-H),7.78(d,1H,C27-H),8.19(d,1H,C25-H),8.54(d,1H,C29 -H),10.77(s,1H,NH7-H),13.19(s,1H,OH32-H),13.42(s,1H,OH15-H). Example 4: Compound 4

[0178] Compound CORE-B (2.6 g, 10 mmol) was added to 1 N HCl (26 mL), followed by 10 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (0.76 g, 8 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-1 (2.25 g, 9 mmol) was then added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. EtOH (26 mL) was then added, and the mixture was slowly allowed to rise to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) indicated the reaction was complete.

[0179] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (30 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound B1-1 (4 g).

[0180] ¹H NMR (DMSO-d6,400MHz)δ1.32(s,9H,C32-H,C33-H,C34-H),2.33(s,3H,C18-H) ,3.87(s,3H,C38),6.97-7.01(dd,1H,C11-H),7.43-.46(d,1H,C13-H),7. 49-7.55(m,4H,C26-H,C27-H,C29-H,C30-H),7.69-7.72(dd,1H,C21-H),7 .83-7.89(m,2H,C20-H,C23-H),9.48(s,1H,NH7-H),13.43(s,1H,OH15-H). Compound B1-1 (3.12 g, 6 mmol) was added to MeOH (62 mL), followed by an aqueous solution of lithium hydroxide (0.86 g, 10 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) showed the reaction was complete.

[0181] After removing methanol by concentration under reduced pressure, 60 mL of water was added, and impurities were removed by extraction with 25 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl and extracted with EA (30 mL x 3). After combining the organic phases, the mixture was washed once with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 4 (1.67 g, yield: 55.1%).

[0182]

[0183] ¹H NMR(DMSO-d6,400MHz)δ1.33(s,9H,C32-H,C33-H,C34-H),2.34(s,3H,C18-H),6.98-7.01(dd,1H,C11-H),7.45-7.47(d,1H,C13-H),7.50-7.56(m ,4H,C26-H,C27-H,C29-H,C30-H),7.70-7.73(dd,1H,C21-H),7.84-7.90 (m,2H,C20-H,C23-H),9.48(s,1H,NH7-H),13.43(s,2H,OH15-H,OH37-H). Example 5: Compound 5

[0184] Compound CORE-B (2.6 g, 10 mmol) was added to 1 N HCl (26 mL), followed by 10 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (0.76 g, 10 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-2 (2.7 g, 9 mmol) was then added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. EtOH (25 mL) was then added, and the mixture was slowly allowed to rise to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed, indicating the reaction was complete.

[0185] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (30 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound B2-1 (3.45 g).

[0186] ¹H NMR (DMSO-d6,400) MHz)δ1.33(s,9H,C35-H,C36-H,C37-H),2.37(s,3H,C18-H),3.87(s,3H,C28 -H),6.99-7.02(dd,1H,C11-H),7.43-7.46(dd,1H,C13-H),7.50-7.57(m,4H ,C29-H,C30-H,C32-H,C33-H),8.01-8.03(d,1H,C21-H),8.28-8.30(d,1H,C 20-H),8.45-8.46(d,1H,C24-H),9.58(s,1H,NH7-H),13.48(s,1H,OH15-H). Compound B2-1 (2.85 g, 5 mmol) was added to MeOH (60 mL), followed by the addition of lithium hydroxide. (0.72 g, 8 mL H2O) aqueous solution, reacted overnight at 50-60 °C. TLC analysis was performed on a sample (PE / EA = 3 / 1.5, 254 nm), indicating the reaction was complete.

[0187] After concentrating the reaction system under reduced pressure to remove methanol, 60 mL of water was added, and impurities were removed by extraction with 30 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl, allowed to stand at 5-0℃ for 5 h, and the filter cake was collected by filtration to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 2) to obtain the target compound 5 (1.84 g, yield 66.7%).

[0188]

[0189] ¹H NMR(DMSO-d6,400MHz)δ1.33(s,9H,C31-H,C32-H,C33-H),2.37(s,3H,C18-H),6.99-7.0 2(dd,J=8.4Hz,1H,C11-H),7.44-7.47(dd,J=8.4Hz,1H,C13-H),7.51-7.57(m,4H,C25-H ,C26-H,C28-H,C29-H),7.99-8.01(d,J=8Hz,1H,C21-H),8.25-8.27(d,J=8.4Hz,1H,C20 -H),8.42-8.43(d,J=4Hz,1H,C24-H),9.57(s,1H,NH7-H),13.52(s,2H,OH15-H,OH36-H). Example 6: Compound 6

[0190] Compound CORE-B (2.6 g, 10 mmol) was added to 1 N HCl (26 mL), followed by 10 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (0.76 g, 10 mL H2O) was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-3 (2.09 g, 9 mmol) was then added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. EtOH (30 mL) was then added, and the mixture was slowly allowed to rise to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) indicated the reaction was complete.

[0191] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (30 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound B3-1 (3.61 g).

[0192] ¹H NMR(DMSO-d6,400MHz)δ1.33(s,9H,C31-H,C32-H,C33-H),2.35(s,3H,C18-H),3.8 9(s,3H,C37-H),6.96-6.99(dd,1H,C11-H),7.40-7.43(dd,1H,C13-H),7.50-7.63( m,5H,C21-H,C25-H,C26-H,C28-H,C29-H),7.78-7.80(dd,1H,C22-H),8.17-8.20( m,1H,C20-H),8.53-8.54(d,1H,C24-H),9.51(s,1H,NH7-H),13.55(s,1H,OH15-H). Compound B3-1 (3 g, 6 mmol) was added to MeOH (60 mL), followed by an aqueous solution of lithium hydroxide (0.86 g, 8.6 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed, and the reaction was considered complete.

[0193] After concentrating the reaction system under reduced pressure to remove methanol, 60 mL of water was added, and impurities were removed by extraction with 30 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl, allowed to stand at 0-5℃ for 5 h, and filtered to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 6 (2.07 g, yield 70.6%).

[0194]

[0195] ¹H NMR(DMSO-d6,400MHz)δ:1.33(s,9H,C31-H,C32-H,C33-H),2.37(s,3H,C18-H),6.9 7-7.01(dd,1H,C11-H),7.44-7.47(dd,1H,C13-H),7.51-7.61(m,5H,C21-H,C25-H, C26-H,C28-H,C29-H),7.78-7.80(d,1H,C22-H),8.16-8.19(dd,1H,C20-H),8.53-8 .54(d,1H,C24-H),9.49(s,1H,NH7-H),13.14(s,1H,OH36-H),13.58(s,1H,OH15-H). Example 7: Compound 7

[0196] Compound CORE-C (3.26 g, 15 mmol) was added to 1 N HCl (35 mL), and the mixture was cooled to 0 °C. NaNO2 (1.15 g, 12 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-1 (3.38 g, 13.5 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (35 mL) was added, and the mixture was slowly heated to room temperature and reacted overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed, indicating the reaction was complete.

[0197] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and extracted with EA (35 mL x 3). After the organic phases were combined, the mixture was dried with 35 mL of saturated brine, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound C1-1 (4.8 g).

[0198] ¹H NMR(DMSO-d6,400MHz)δ2.33(s,3H,C18-H),2.36(s,3H,C31-H),3.89(s,3H,C35-H),6.95-6.98(dd,1H ,C11-H),7.28-7.30(d,2H,C27-H,C29-H),7.41-7.44(dd,1H,C13-H),7.46-7.49(d,2H,C26-H,C30-H), 7.69-7.73(dd,1H,C21-H),7.83-7.90(m,2H,C20-H,C23-H),9.48(s,1H,NH7-H),13.45(s,1H,OH15-H). Compound C1-1 (3.84 g, 8 mmol) was added to MeOH (80 mL), followed by an aqueous solution of lithium hydroxide (1.15 g, 12 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis was performed on a sample (PE / EA = 3 / 1.5, 254 nm), indicating the reaction was complete.

[0199] After concentrating the reaction system under reduced pressure to remove methanol, 80 mL of water was added, and impurities were removed by extraction with 30 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl, stirred at 0-5℃ for 3 h, and filtered to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 7 (2.56 g, yield 69%).

[0200]

[0201] ¹H NMR(DMSO-d6,400MHz)δ2.33(s,3H,C18-H),2.36(s,3H,C31-H),6.95-6.98(dd,1H,C11-H),7.28-7.30(d,2H,C27-H,C29-H),7.46-7.49(m,3H,C1 3-H,C26-H,C30-H),7.69-7.73(dd,1H,C21-H),7.83-7.90(m,2H,C20-H, C23-H),9.46(s,1H,NH7-H),13.39(s,1H,OH34-H),13.44(s,1H,OH15-H). Example 8: Compound 8

[0202] Compound CORE-C (3.26 g, 15 mmol) was added to 1 N HCl (35 mL), and the solution was cooled to 0 °C. NaNO2 (1.2 g, 12 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-2 (4.1 g, 13.5 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (35 mL) was added, and the solution was slowly heated to room temperature and reacted overnight. TLC analysis (PE / EA = 3 / 2, 254 nm) was performed, indicating the reaction was complete.

[0203] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (35 mL x 3). After the organic phases were combined, the mixture was washed once with 35 mL of saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound C2-1 (5.94 g).

[0204] ¹H NMR(DMSO-d6,400MHz)δ2.36(s,6H,C18-H,C30-H),3.87(s,3H,C34),6.94-6 .98(dd,1H,C11-H),7.26-7.28(d,2H,C26-H,C28-H),7.40-7.43(dd,1H,C13- H),7.48-7.50(d,2H,C25-H,C29-H),7.96-7.98(d,1H,C21-H),8.22-8.25(d d,1H,C20-H),8.40(d,1H,C24-H),9.55(s,1H,NH7-H),13.50(s,1H,OH15-H). Compound C2-1 (5.3 g, 10 mmol) was added to MeOH (110 mL), followed by an aqueous solution of lithium hydroxide (1.4 g, 14 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 2, 254 nm) showed the reaction was complete.

[0205] After concentrating the reaction system under reduced pressure to remove methanol, 110 mL of water was added, and impurities were removed by extraction with 50 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1 N HCl, stirred at 0-5℃ for 3 h, and the filter cake was collected by filtration to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 2) to obtain the target compound 8 (3.5 g, yield 68.1%).

[0206]

[0207] ¹H NMR(DMSO-d6,400MHz)δ2.36(s,6H,C18-H,C30-H),6.94-6.98(dd,1H,C11 -H),7.28-7.30(d,2H,C26-H,C28-H),7.41-7.44(dd,1H,C13-H),7.48-7.5 0(d,2H,C25-H,C29-H),7.98-8.00(d,1H,C21-H),8.23-8.26(dd,1H,C20- H),8.41(d,1H,C24-H),9.53(s,1H,NH7-H),13.50(s,2H,OH15-H,OH33-H). Example 9: Compound 9

[0208] Compound CORE-C (3.26 g, 15 mmol) was added to 1 N HCl (35 mL), and the solution was cooled to 0 °C. NaNO2 (1.2 g, 12 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-3 (3.13 g, 13.5 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (35 mL) was added, and the solution was slowly heated to room temperature and reacted overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) showed that the reaction was complete.

[0209] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (35 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (35 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound C3-1 (3.81 g).

[0210] ¹H NMR(DMSO-d6,400MHz)δ2.36,2.38(s,6H,C18-H,C30-H),3.89(s,3H,C34-H),6.94-6 .98(dd,1H,C11-H),7.29-7.30(d,2H,C26-H,C28-H),7.42-7.44(dd,1H,C13-H),7.49 -7.51(d,2H,C25-H,C29-H),7.60-7.64(t,1H,C21-H),7.79-7.81(d,1H,C22-H),8.1 8-8.21(d,1H,C20-H),8.55(s,1H,C24-H),9.53(s,1H,NH7-H),13.57(s,1H,OH15-H). Compound C3-1 (3.75 g, 8 mmol) was added to MeOH (75 mL), followed by an aqueous solution of lithium hydroxide (1.15 g, 12 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed on a sample, indicating the reaction was complete.

[0211] After removing methanol by concentrating the reaction system under reduced pressure, 75 mL of water was added, and impurities were removed by extraction with 30 mL of EA. Then, the aqueous phase was adjusted to pH 2-3 with 1N HCl, and extracted with EA (40 mL x 3) (or the filter cake was collected by direct filtration). After the organic phases were combined, the mixture was washed once with saturated brine (35 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product.

[0212] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 9 (2.61 g, yield 73.3%).

[0213]

[0214] ¹H NMR(DMSO-d6,400MHz)δ2.36(s,3H,C18-H),2.37(s,3H,C30-H),6.95-6.98(dd,1H,C11-H),7.29-7.31(d,2H,C26-H,C28-H),7.43-7.4 (dd,1H,C13-H),7.49-7.51(d,2H,C25-H,C29-H),7.57-7.61(t,1H,C21-H),7.78-7.79(d,1H,C22-H),8.16-8 .18(d,1H,C20-H),8.53-8.54(d,1H,C24-H),9.47(s,1H,NH7-H),13.14(s,1H,OH33-H),13.59(s,1H,OH15-H). Example 10: Compound 10

[0215] Compound CORE-D (4.34 g, 20 mmol) was added to 1 N HCl (45 mL), and the solution was cooled to 0 °C. NaNO2 (1.52 g, 15 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-1 (4.5 g, 18 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (45 mL) was added, and the reaction was slowly allowed to proceed to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed, indicating the reaction was complete.

[0216] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (50 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (50 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound D1-1 (7.86 g).

[0217] ¹H NMR(DMSO-d6,400MHz)δ:2.16(s,3H,C31-H),2.38(s,3H,C18-H),3.89(s,3H,C35 ),6.79-6.82(dd,1H,C11-H),7.22-7.24(d,1H,C27-H),7.27-7.29(dd,1H,C13-H) ,7.30-7.34(m,2H,C28-H,C29-H),7.49-7.52(dd,1H,C30-H),7.71-7.75(t,1H,C2 1-H),7.85-7.91(m,2H,C20-H,C23-H),9.39(s,1H,NH7-H),13.41(s,1H,OH15-H). Compound D1-1 (7.2 g, 15 mmol) was added to MeOH (145 mL), followed by an aqueous solution of lithium hydroxide (2.16 g, 22 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) showed the reaction was complete.

[0218] After removing methanol by concentrating the reaction system under reduced pressure, 150 mL of water was added, and impurities were removed by extraction with 50 mL of EA. Then, the aqueous phase was adjusted to pH 2-3 with 1N HCl, stirred at 0-5℃ for 5 hours, and the filter cake was collected by filtration to obtain the crude product.

[0219] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 10 (4.94 g, yield 70.9%).

[0220]

[0221] ¹H NMR(DMSO-d6,400MHz)δ2.14(s,3H,C31-H),2.36(s,3H,C18-H),6.78-6.81(dd ,1H,C11-H),7.20-7.22(d,1H,C27-H),7.25-7.28(dd,1H,C13-H),7.29-7.33(m ,2H,C28-H,C29-H),7.47-7.50(dd,1H,C30-H),7.69-7.73(t,1H,C21-H),7.83 -7.89(m,2H,C20-H,C23-H),9.38(s,1H,NH7-H),13.40(s,2H,OH15-H,OH34-H). Example 11: Compound 11

[0222] Compound CORE-D (2.18 g, 10 mmol) was added to 1 N HCl (12.5 mL), and the solution was cooled to 0 °C. NaNO2 (7.6 g, 8 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-2 (2.7 g, 9 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (25 mL) was added, and the solution was slowly heated to room temperature and reacted overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) was performed, indicating the reaction was complete.

[0223] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (25 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (25 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound D2-1 (3.96 g).

[0224] ¹H NMR(DMSO-d6,400MHz)δ2.16(s,3H,C30-H),2.37(s,3H,C18-H),3.89(s,3H,C3 4),6.79-6.82-(dd,1H,C11-H),7.21-7.24(m,2H,C13-H,C26-H),7.34-7.35(d ,2H,C27-H,C28-H),7.46(d,1H,C29-H),7.97-8.00(dd,1H,C20-H),8.25(d,1H ,C21-H),8.39-8.41(d,2H,C24-H),9.45(s,1H,NH7-H),13.52(s,1H,OH15-H). Compound D2-1 (3.7 g, 7 mmol) was added to MeOH (65 mL), followed by an aqueous solution of lithium hydroxide (1 g, 10 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis was performed on a sample (PE / EA = 3 / 1.5, 254 nm), indicating the reaction was complete.

[0225] After removing methanol by concentrating the reaction system under reduced pressure, 65 mL of water was added, and impurities were removed by extraction with 30 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl and stirred at 0-5℃ for 5 h to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 2) to obtain the target compound 11 (2.59 g, yield 71.9%).

[0226]

[0227] ¹H NMR(DMSO-d6,400MHz)δ2.16(s,3H,C30-H),2.37(s,3H,C18-H),6.79-6.82(dd ,1H,C11-H),7.21-7.24(m,2H,C13-H,C26-H),7.33-7.34(d,2H,C27-H,C28-H), 7.46(d,1H,C29-H),7.97-8.00(dd,H,C20-H),8.24(d,1H,C21-H),8.40-8.41( d,2H,C24-H),9.46(s,1H,NH7-H),13.46(s,1H,OH33-H),13.51(s,1H,OH15-H). Example 12: Compound 12

[0228] Compound CORE-D (2.18 g, 10 mmol) was added to 1 N HCl (12.5 mL), and the solution was cooled to 0 °C. NaNO2 (7.8 g, 8 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-3 (2.1 g, 9 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (25 mL) was added, and the reaction was slowly allowed to proceed to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) showed that the reaction was complete.

[0229] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (25 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (25 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound D3-1 (3.1 g).

[0230] ¹H NMR(DMSO-d6,400MHz)δ2.16(s,3H,C34-H),2.36(s,3H,C18-H),3.88(s,3H,C33-H) ,6.77-6.80(dd,1H,C11-H),7.22-7.34(m,4H,C13-H,C26-H,C27-H,C28-H),7.45-7 .48(dd,1H,C29-H),7.58-7.62(t,1H,C21-H),7.78-7.80(d,1H,C22-H),8.17-8.20 (m,1H,C20-H),8.53-8.54(d,1H,C24-H),9.40(s,1H,NH7-H),13.52(s,1H,OH15-H). Compound D3-1 (2.76 g, 6 mmol) was added to MeOH (45 mL), followed by an aqueous solution of lithium hydroxide (0.86 g, 10 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) showed the reaction was complete.

[0231] After removing methanol by concentrating the reaction system under reduced pressure, 50 mL of water was added, and impurities were removed by extraction with EA. Then, the aqueous phase was adjusted to pH 2-3 with 1 NHCl, and extracted with EA (30 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product.

[0232] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain target compound 12 (1.39 g, yield 52%).

[0233]

[0234] ¹H NMR(DMSO-d6,400MHz)δ2.16(s,3H,C30-H),2.36(s,3H,C18-H),6.77-6.80(dd,1H,C11-H),7. 22-7.26(dd,1H,C13-H),7.26-7.29(dd,1H,C26-H),7.30-7.34(m,2H,C27-H,C28-H),7.46-7.4 9(dd,1H,C29-H),7.56-7.60(t,1H,C21-H),7.77-7.79(dd,1H,C22-H),8.15-8.18(dd,1H,C20- H),8.51-8.52(d,1H,C24-H),9.37(s,1H,NH7-H),13.13(s,1H,OH33-H),13.54(s,1H,OH15-H). Example 13: Compound 13

[0235] Compound CORE-E (3.5 g, 15 mmol) was added to 1 N HCl (35 mL), followed by 15 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (1.15 g, 12 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-1 (3.38 g, 13.5 mmol) was then added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. EtOH (35 mL) was then added, and the mixture was slowly allowed to rise to room temperature overnight. TLC analysis (PE / EA = 3 / 1.5, 254 nm) indicated the reaction was complete.

[0236] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (35 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (35 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound E1-1 (5.2 g).

[0237] ¹H NMR(DMSO-d6,400MHz)δ2.3(s,3H,C18-H),3.80(s,3H,C36-H),3.9(s,3H,C28-H),6.8(dd,1H,C11-H),7.1(d,2H-H,C31-H,C33-H),7.4( dd,1H,C13-H),7.5(d,2H,C30-H,C34-H),7.6-7.7(t,1H,C21-H),7.8-7.9(m,2H,C20-H,C23-H),9.5(s,1H,NH7-H),13.5(s,1H,OH15-H). Compound E1-1 (4.95 g, 10 mmol) was added to MeOH (100 mL), followed by an aqueous solution of lithium hydroxide (1.5 g, 15 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) showed the reaction was complete.

[0238] After concentrating the reaction system under reduced pressure to remove methanol, 100 mL of water was added, and impurities were removed by extraction with 30 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl, and stirred at 0-5℃ for 5 h. The crude product was then filtered to obtain the crude product. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1.5) to obtain the target compound 13 (3.85 g, 7.8%).

[0239]

[0240] ¹HNMR(DMSO-d6,400MHz)δ2.33(s,3H,C32-H),3.80(s,3H,C31-H),6.95-6 .98(dd,1H,C11-H),7.03-7.05(d,2H,C26-H,C28-H),7.42-7.45(dd,1H,C1 3-H),7.53-7.55(d,2H,C25-H,C29-H),7.69-7.73(t,1H,C20-H),7.83-7.9 5(m,2H,C19-H,C22-H),9.43(s,1H,NH7-H),13.45(s,2H,OH15-H,OH33-H). Example 14: Compound 14

[0241] Compound CORE-E (3.5 g, 15 mmol) was added to 1 N HCl (35 mL), followed by 15 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (1.2 g, 12 mL H2O) aqueous solution was added dropwise at 0–5 °C. After the addition was complete, the reaction mixture was kept at 0–5 °C for 0.5 h. Compound CORE-2 (4.05 g, 13.5 mmol) was then added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. EtOH (35 mL) was then added, and the mixture was slowly allowed to rise to room temperature overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) indicated the reaction was complete.

[0242] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (35 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (35 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound E2-1 (6.1 g).

[0243] ¹H NMR(CDCl3,400MHz)δ2.41(s,3H,C18-H),3.89(s,3H,C35-H),3.94(s,3H,C2 8-H),5.81(s,1H,NH7-H),6.81-6.84(dd,1H,C11-H),7.05-7.07(d,2H,C30- H,C32-H),7.26-7.42(m,3H,C13-H,C29-H,C33-H),7.89-7.91(d,1H,C21-H) ,8.31-8.33(dd,1H,C20-H),8.48-8.49(d,1H,C24-H),13.57(s,1H,OH15-H). Compound E2-1 (5.45 g, 10 mmol) was added to MeOH (110 mL), followed by an aqueous solution of lithium hydroxide (1.5 g, 15 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis was performed on a sample (PE / EA = 3 / 1.5, 254 nm), indicating the reaction was complete.

[0244] After removing methanol by concentrating the reaction system under reduced pressure, 110 mL of water was added, and impurities were removed by extraction with 50 mL of EA. Then, the aqueous phase was adjusted to pH 2-3 with 1N HCl, and stirred at 0-5℃ for 5 hours. The crude product was obtained by filtration.

[0245] The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1.5) to obtain target compound 14 (3.65 g, yield 68.9%).

[0246]

[0247] ¹H NMR(DMSO-d6,400MHz)δ2.37(s,3H,C18-H),3.81(s,3H,C34-H),6.96-6.99(dd,1H,C11-H),7.04-7.06(d,2H,C29-H,C31-H),7.40-7 .43(dd,1H,C13-H),7.54-7.56(d,2H,C28-H,C32-H),7.99-8.01(d,1H,C21-H),8.25-8.27(dd,1H,C20-H),8.43(d,1H,C24-H),9.51 (s, 1H, NH7-H), 13.52 (s, 2H, OH15-H, OH27-H). Example 15: Compound 15

[0248] Compound CORE-E (3.5 g, 15 mmol) was added to 1 N HCl (35 mL), followed by 15 mL of EtOH. The mixture was cooled to 0 °C. NaNO2 (1.2 g, 12 mL H2O) aqueous solution was added dropwise under controlled temperature at 0–5 °C. After the addition was complete, the reaction was maintained at 0–5 °C for 0.5 h. Compound CORE-3 (3.12 g, 13.5 mmol) was added, and the pH of the reaction system was adjusted to 9–10 with saturated Na2CO3 aqueous solution. Then, EtOH (35 mL) was added, and the mixture was slowly heated to room temperature and reacted overnight. TLC analysis (PE / EA = 3 / 1, 254 nm) showed that the reaction was complete.

[0249] The pH of the reaction system was adjusted to 2-3 with 1 N HCl, and the mixture was extracted with EA (50 mL x 3). After the organic phases were combined, the mixture was washed once with saturated brine (50 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to column chromatography to obtain the target compound E3-1 (5.68 g).

[0250] ¹H NMR(DMSO-d6,400MHz)δ2.3(s,3H,C18),3.81(s,3H,C35),3.89(s,3H,C34),6 .94-6.97(dd,1H,C11),7.04-7.06(d,2H,C26,C28),7.39-7.42(dd,1H,C13), 7.54-7.56(d,2H,C25,C29),7.59-7.63(t,1H,C21),7.79-7.81(dd,1H,C22), 8.18-8.21(m,1H,C20),8.55(s1H,C24).9.46(s,1H,NH7),13.58(s,1H,OH15). Compound E3-1 (4.76 g, 10 mmol) was added to MeOH (100 mL), followed by an aqueous solution of lithium hydroxide (1.5 g, 15 mL H2O). The reaction was carried out overnight at 50-60 °C. TLC analysis (PE / EA = 3 / 1, 254 nm) showed the reaction was complete.

[0251] After concentrating the reaction system under reduced pressure to remove methanol, 100 mL of water was added, and impurities were removed by extraction with 30 mL of EA. The aqueous phase was then adjusted to pH 2-3 with 1N HCl, and stirred at 0-5℃ for 6 h. The crude product was collected by filtration. The crude product was purified by silica gel column chromatography (PE / EA = 5 / 1) to obtain the target compound 15 (2.62 g, 56.7%).

[0252]

[0253] ¹H NMR(DMSO-d6,400MHz)δ2.36(s,3H,C18-H),3.81(s,3H,C34-H),6.94-6.97(dd,1H,C11-H ),7.04-7.06(d,2H,C26-H,C28-H),7.40-7.43(dd,1H,C13-H),7.54-7.56(d,2H,C25-H,C 29-H),7.57-7.61(t,1H,C21-H),7.77-7.79(dd,1H,C22-H),8.15-8.18(dd,1H,C20-H),8 .52-8.53(d,1H,C24-H),9.44(s,1H,NH7-H),13.13(s,1H,OH32-H),13.59(s,1H,OH15-H). Efficacy verification 1. Cell Culture Human hepatocellular carcinoma cells (HuH-7) and rat cardiomyocytes (H9c2) were resuscitated and transferred to conventional culture dishes. They were cultured in DMEM medium (containing 10% FBS) at 37°C in a 5% CO2 incubator. When the cells covered 80%–95% of the dish bottom, they were digested with trypsin containing 0.25% EDTA to disperse them into a single-cell suspension. The cell density was then adjusted to 2 × 10⁶ cells / cells using fresh culture medium. 5 Cells / mL were then seeded into 6-well cell culture plates at a rate of 2 mL / well, and cultured in a cell culture incubator for 24 h to allow the cells to confluent in each well. Three samples were obtained in parallel.

[0254] 2. Establishment of cell models The fully grown 6-well plates were divided into a blank group and an experimental group. The blank group was added with 2 mL of DMEM complete medium (containing 10% FBS + 1% antibiotics), and the experimental group was added with 2 mL of complete medium containing ferric citrate (1.3 mL of ferric citrate stock solution was added to 128.7 mL of DMEM complete medium and mixed well). The plates were incubated for 24 h.

[0255] 3. Cell drug delivery and sample assay After 24 hours of incubation, the cells were washed twice with PBS. 2 mL of drug-containing DMEM complete medium was added to each well of the experimental group and incubated for 4 hours; 2 mL of DMEM complete medium was added to each well of the control group and incubated for 4 hours. After 4 hours, the medium was removed, the cells were washed once with PBS, and then digested with trypsin. Cells were counted, centrifuged at 800 rpm for 5 minutes, the medium was discarded, and the cells were lysed by adding acetate-sodium acetate buffer (pH 4.2) and placing the cells on ice for 10 minutes. After centrifugation at 15000×g at 4℃ for 10 minutes, 80 μL of the supernatant was added to 80 μL of hydroxylamine hydrochloride solution (10% w / v), mixed well, and incubated at 37℃ for 40 minutes. The OD value was measured at 593 nm using a microplate reader.

[0256] Cell lines and experimental systems are shown in Table 1 below.

[0257] Table 1 Cell lines and experimental systems

[0258] The effects of the compound and positive control drug on iron removal in human liver cancer cells (HuH-7) are shown in Table 2.

[0259] Table 2. Effects of compounds and positive control agents on iron removal in human hepatocellular carcinoma cells (HuH-7).

[0260] Experimental results showed that compounds 1-15 provided by this invention all exhibited iron ion scavenging effects. Among them, compounds 6, 14, and 12 showed excellent iron ion scavenging effects in HuH-7 cells, significantly higher than the two positive control drugs.

[0261] The effects of the compounds and positive control drugs on iron removal from rat cardiomyocytes (H9c2) are shown in Table 3.

[0262] Table 3. Effects of compounds and positive control agents on iron removal in rat cardiomyocytes (H9c2).

[0263] Experimental results showed that compounds 1-15 provided by this invention all exhibited iron ion scavenging effects in H9c2 cells. Among them, compounds 4, 10, and 14 showed excellent iron ion scavenging effects, significantly higher than the two positive control drugs.

[0264] The above description, in conjunction with specific embodiments, further illustrates the present invention. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions to the details and form of the technical solutions of the present invention can be made without departing from the spirit and scope of the invention, and all such modifications and substitutions fall within the protection scope of the present invention.

Claims

1. An iron chelating agent, characterized in that, The compound represented by formula (I), its stereoisomers, its tautomers, its crystalline hydrates, its solvates, its prodrugs, or its pharmaceutically acceptable salts. （I） In the formula, R is a substituted or unsubstituted phenyl group or a substituted or unsubstituted furanyl group, wherein the substituent of the phenyl group is an alkyl or alkoxy group, and the substituent of the furanyl group is an alkyl group; R1 is H or a halogen; R2 is H, carboxyl, or trihalomethyl; R3 is H, a carboxyl group, or a carboxylic acid ester.

2. The iron chelating agent according to claim 1, characterized in that, It has at least one of the following characteristics: R is a substituted or unsubstituted phenyl group, wherein the substituent of the phenyl group is an alkyl or alkoxy group; R1 is H or a halogen; R2 is H or a trihalomethyl; R3 is a carboxyl group.

3. The iron chelating agent according to claim 2, characterized in that, It has at least one of the following characteristics: R1 is fluorine, chlorine, bromine or iodine; R2 is trifluoromethyl, trichloromethyl, tribromomethyl, or triiodomethyl.

4. The iron chelating agent according to claim 1, characterized in that, R is a substituted or unsubstituted phenyl group, wherein the substituent of the phenyl group is an alkyl or alkoxy group, R1 is H, R2 is a carboxyl or trihalomethyl group, and R3 is H or a carboxyl group.

5. The iron chelating agent according to claim 1, characterized in that, The phenyl group is substituented with C1-C12 alkyl or C1-C12 alkoxy; the furanyl group is substituented with C1-C12 alkyl.

6. The iron chelating agent according to claim 5, characterized in that, The phenyl group is substituented with C1-C8 alkyl or C1-C8 alkoxy; the furanyl group is substituented with C1-C8 alkyl.

7. The iron chelating agent according to any one of claims 1-6, characterized in that, The compound is selected from the following structures: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 8. The iron chelating agent according to claim 7, characterized in that, The compound is selected from the following structures: 、 、 。 9. The iron chelating agent according to claim 7, characterized in that, The compound is selected from the following structures: 、 、 。 10. The iron chelating agent according to claim 7, characterized in that, The compound is selected from the following structures: 。 11. The method for preparing the iron chelating agent according to any one of claims 1-10, characterized in that, The preparation method of the compound includes the following steps: the aromatic compound CORE-X and the heterocyclic compound CORE-n undergo diazotization-coupling reaction and post-treatment to obtain the compound; In the formula, R, R1, R2 and R3 have the same definition as above, X is a letter of A, B, C, D, E, F, G, H or I, and n is an integer from 1 to 15.

12. The preparation method according to claim 11, characterized in that, The diazotization-coupling reaction is as follows: the aromatic compound CORE-X undergoes a diazotization reaction with sodium nitrite in a solvent, and then undergoes a coupling reaction with the heterocyclic compound CORE-n and an alcohol under an alkaline environment.

13. The preparation method according to claim 11, characterized in that, The diazotization reaction is carried out at a temperature of 0-5℃ for 0.5-10 hours.

14. The preparation method according to claim 11, characterized in that, The solvent is 0.5-10N hydrochloric acid; preferably, the solvent further includes a co-solvent, and more preferably, the co-solvent is selected from at least one of acetonitrile, dichloromethane, ethanol, methanol, isopropanol and n-propanol.

15. The preparation method according to claim 11, characterized in that, The coupling reaction is carried out at room temperature for 6-24 hours.

16. The preparation method according to claim 11, characterized in that, The alcohol is a C1-C6 alcohol, preferably at least one of methanol, ethanol, propanol and butanol.

17. The preparation method according to claim 11, characterized in that, The alkaline environment is defined as a pH of 8-12.

18. The preparation method according to claim 11, characterized in that, The post-processing includes extraction, washing, drying with anhydrous sodium sulfate, filtration, and drying.

19. The preparation method according to claim 11, characterized in that, The post-treatment process also includes a hydrolysis step, specifically: the post-treatment product is hydrolyzed with alkali in methanol solvent, extracted, and the organic phase is washed, dried with anhydrous sodium sulfate, filtered, and dried.

20. The preparation method according to claim 11, characterized in that, The preparation method of the aromatic compound CORE-X includes the following steps: (i) 2-Bromo-4-fluoro-6-nitrophenol, a base and BnBr undergo an etherification reaction to give compound II; (ii) The organoboron compound and compound II react in the presence of a palladium catalyst and sodium carbonate to give an intermediate compound; (iii) The intermediate compound and hydrogen react in the presence of a hydrogenation catalyst to obtain the aromatic compound CORE-X.

21. The preparation method according to claim 20, characterized in that, The structure of compound II in step (i) is as follows: ; The structure of the organoboron compound described in step (ii) is as follows: The structure of the intermediate compound in step (ii) is as follows: In the formula, R has the same definition as any one of claims 1-10 above.

22. The preparation method according to claim 11, characterized in that, The method for preparing the heterocyclic compound CORE-n includes the following steps: (I) Aromatic primary amine compounds react with sodium nitrite, and after the reaction, hydrochloric acid solution containing tin chloride is added and filtered to obtain aromatic hydrazine compounds; (II) Aromatic hydrazine compounds and β-keto esters undergo a cyclization reaction in the presence of acetic acid, sodium acetate, and ethyl acetoacetate to obtain the heterocyclic compound CORE-n.

23. The preparation method according to claim 22, characterized in that, The structure of the aromatic primary amine compound described in step (I) is as follows: In the formula, R1, R2 and R3 have the same definition as any one of the preceding claims 1-10.

24. The preparation method according to claim 22, characterized in that, The structure of the aromatic hydrazine compound described in step (II) is as follows: In the formula, R1, R2 and R3 have the same definition as any one of the preceding claims 1-10.

25. A pharmaceutical composition, characterized in that, Includes the iron chelating agent as described in any one of claims 1-10 and pharmaceutically acceptable excipients.

26. Use of the iron chelating agent according to any one of claims 1-10 or the pharmaceutical composition according to claim 25 in the preparation of a medicament for improving iron overload.

27. The use of the iron chelating agent according to any one of claims 1-10 or the pharmaceutical composition according to claim 25 in the preparation of a medicament for the prevention or adjunctive treatment of iron overload-related diseases.

28. The application according to claim 27, characterized in that... The iron overload-related diseases are selected from hereditary hemochromatosis, thalassemia, aplastic anemia, pure red cell aplasia, paroxysmal nocturnal hemoglobinuria, primary myelofibrosis, congenital bone marrow failure diseases, neurodegenerative diseases, liver diseases, heart diseases, vascular diseases, or endocrine diseases.

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