Sorafenib-cholic acid coupling prodrug prepared through step-by-step coupling based on sorafenib modular assembly and method

Abstract

The invention provides a method for preparing a sorafenib-cholic acid coupling prodrug based on step-by-step coupling of sorafenib modular assembly, which comprises the following steps of: firstly synthesizing a complete sorafenib part by taking tert-butyl-(iodo-oxy) dimethylsilane as a linker, and after a sorafenib module is assembled, preparing the sorafenib-cholic acid coupling prodrug through step-by-step coupling, thereby obtaining the sorafenib-cholic acid coupling prodrug. And then coupling with cholic acid compounds step by step through deprotection. According to the method, the reaction steps are greatly reduced, the reaction can be carried out under the room temperature condition, the safety of the synthesis process is improved, especially depending on the unique connexon design and through the specific binding mechanism of the connexon and the sorafenib module, on one hand, the yield of each reaction step is remarkably improved, and on the other hand, the yield of the sorafenib module is greatly increased; the preparation efficiency of a target product is greatly improved; and on the other hand, side reaction is blocked from the reaction source, so that the purification difficulty of the product is reduced, and the controllability of the whole synthesis process is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological medicine, in particular to a sorafenib-cholic acid conjugate prodrug based on modular assembly of sorafenib and a preparation method thereof. BACKGROUND

[0002] The oil-water partition coefficient value of sorafenib (SOR) is 6.08, which is almost insoluble in water, and belongs to a typical BCS II drug; at the same time, SOR is difficult to dissolve in gastrointestinal pH medium, resulting in low bioavailability, large individual difference, and limited clinical application.

[0003] The main solubilization technologies at present include: (1) physical modification: micronization, nanocrystal technology; (2) chemical modification: salt formation, prodrug design; (3) dosage form optimization: solid dispersion, inclusion compound, prodrug, etc. Among them, the prodrug refers to a design strategy that converts an active drug into an inactive or low-activity form through chemical modification, and releases the original drug in the body after metabolism (such as enzymatic hydrolysis, reduction, etc.), thereby playing a therapeutic role.

[0004] The advantages of prodrugs mainly include the following aspects: (1) improving the absorption and bioavailability of drugs, such as increasing the liposolubility: by modifying the polarity group (such as carboxylic acid, phosphoric acid esterification), the ability of the drug to pass through the cell membrane is improved, and the oral absorption is promoted, at the same time, some prodrugs overcome the first-pass effect, reduce liver metabolism, and thus improve the bioavailability; (2) enhancing the targeting and reducing the systemic toxicity: prodrugs can be activated at specific sites (such as tumors, inflammation), reducing the toxicity to normal tissues; (3) prolonging the action time of the drug, having a slow-release effect: prodrugs are slowly metabolized into the original drug, maintaining a stable blood drug concentration. Therefore, the design of drugs into prodrugs can improve drug release, improve gastrointestinal absorption and oral bioavailability.

[0005] In the previous research of the inventors' team on the sorafenib-cholic acid conjugate prodrug compound (SOR-LCA), the synthesis mainly includes six stages: the first stage: lithocholic acid is connected with di-tert-butyl dicarbonate (BOC) to protect the hydroxyl group to obtain compound 1; the second stage: compound 1 is linked with 1,4-butanediol linker to obtain compound 2; the third stage: compound 2 is linked with p-toluenesulfonyl chloride (TCl) to obtain compound 3; the fourth stage: compound 3 is linked with the front end of sorafenib to obtain compound 4; the fifth stage: compound 4 is linked with the rear end of sorafenib to obtain compound 5; the sixth stage: compound 5 is removed from the BOC protecting group to obtain SOR-LCA. This method has many reaction steps, harsh reaction conditions, resulting in poor total yield of synthesized drugs, and low reaction efficiency and poor safety. SUMMARY

[0006] The present application aims at the deficiencies of the prior art, and provides a sorafenib-cholic acid conjugate prodrug prepared by step-by-step coupling based on modular assembly of sorafenib and a method.

[0007] According to a first aspect of the present application, a method for preparing a sorafenib-cholic acid conjugate prodrug by step-by-step coupling based on modular assembly of sorafenib is provided, comprising the following steps:

[0008] Tert-butyl-(iodoxy)dimethylsilane is linked to the front end of sorafenib to obtain a first compound; wherein the structural formula of the first compound is shown as Formula I;

[0009]

[0010] The first compound is linked to the rear end of sorafenib to obtain a second compound; wherein the structural formula of the second compound is shown as Formula II;

[0011]

[0012] The second compound is de-TBSO to alcohol to obtain a third compound; wherein the structural formula of the third compound is shown as Formula III;

[0013]

[0014] The third compound is linked to a cholic acid compound to obtain a sorafenib-cholic acid conjugate prodrug;

[0015] In Formulas I-III, n = 2-10; TBSO: tert-butyldimethylsilyl.

[0016] As an optional implementation, the cholic acid compound is ursodeoxycholic acid, and the structural formula of the sorafenib-cholic acid conjugate prodrug is shown as Formula IV;

[0017]

[0018] In the formula, n = 2-10.

[0019] As an optional implementation, tert-butyl-(iodoxy)dimethylsilane is linked to the front end of sorafenib to obtain a first compound, specifically comprising the following steps:

[0020] At room temperature, 4-(4-aminophenoxy)-N-methyl-2-pyridinecarboxamide is dissolved in anhydrous acetonitrile, and tert-butyl-(iodoxy)dimethylsilane, potassium carbonate and sodium iodide are sequentially added, and after the addition is completed, it is transferred to 90 DEG C for continuous stirring reaction;

[0021] After the reaction is completed, the reaction solution is cooled to room temperature, and the reaction is quenched, extracted, the organic phase is washed, dried, filtered, and the filtrate is distilled under reduced pressure and the crude product is purified to obtain the first compound.

[0022] As an optional embodiment, the equivalent ratio of 4-(4-aminophenoxy)-N-methyl-2-pyridinecarboxamide, tert-butyl-(iodoxy)dimethylsilane, potassium carbonate and sodium iodide is 1:3:3:0.3-1:5:5:1.

[0023] As an optional embodiment, the first compound is linked to the back end of sorafenib to obtain a second compound, specifically comprising the following steps:

[0024] The first compound is dissolved in anhydrous dichloromethane at room temperature, and 4-chloro-3-trifluoromethyl isocyanate and triethylamine are added in sequence, and after the addition is completed, the reaction is continued at room temperature.

[0025] After the reaction is completed, the reaction is quenched, extracted, the organic phase is washed, dried, filtered, and the filtrate is distilled under reduced pressure and the crude product is purified to obtain the second compound.

[0026] As an optional embodiment, the equivalent ratio of the first compound, 4-chloro-3-trifluoromethyl isocyanate and triethylamine is 1:4:5-1:5:8.

[0027] As an optional embodiment, the second compound is de-TBSO to obtain an alcohol to obtain a third compound, specifically comprising the following steps:

[0028] The second compound is dissolved in anhydrous dichloromethane at room temperature, and tetrabutylammonium fluoride is added, and after the addition is completed, the reaction is continued at room temperature.

[0029] After the reaction is completed, the reaction is quenched, extracted, the organic phase is washed, dried, filtered, and the filtrate is distilled under reduced pressure and the crude product is purified to obtain the third compound.

[0030] As an optional embodiment, the equivalent ratio of the second compound and tetrabutylammonium fluoride is 1:2-1:5.

[0031] As an optional embodiment, the third compound is linked to a cholic acid compound to obtain a fourth compound, specifically comprising the following steps:

[0032] The third compound, a cholic acid compound, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride and 4-dimethylaminopyridine are simultaneously dissolved in anhydrous DMF at room temperature, and the reaction is continued at room temperature.

[0033] After the reaction is completed, the reaction is quenched, extracted, the organic phase is washed, dried, filtered, and the filtrate is distilled under reduced pressure and the crude product is purified to obtain the sorafenib-cholic acid conjugate prodrug.

[0034] As an optional embodiment, the equivalent ratio of the third compound, the cholic acid compound, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 4-dimethylaminopyridine is 1:2:4:1 to 1:5:5:3.

[0035] According to a second aspect of the object of the present application, a sorafenib-cholic acid conjugate prodrug prepared by the above method is provided.

[0036] As can be seen from the technical solutions of the present application above, the method for preparing the sorafenib-cholic acid conjugate prodrug in steps based on modular assembly of sorafenib proposed by the present application uses tert-butyl-(iodoxy)dimethylsilane as a linker, synthesizes a complete sorafenib moiety first, and then couples with the cholic acid compound in steps after the sorafenib module is assembled.

[0037] The method greatly reduces the reaction steps and can be carried out at room temperature, improving the safety of the synthesis process. In particular, relying on the unique linker design and the specific binding mechanism of the linker and the sorafenib module, on the one hand, the yield of each reaction step is significantly improved, greatly improving the preparation efficiency of the target product; on the other hand, the occurrence of side reactions is blocked from the source, not only reducing the difficulty of product purification, but also enhancing the controllability of the entire synthesis process. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a synthesis route map of the sorafenib-2C-ursodeoxycholic acid conjugate prodrug compound of the present application.

[0039] Figure 2 is the structural information of compound 1-1 in the synthesis process of the sorafenib-2C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 2 The A part in the compound 1-1 is 1 H-NMR spectrum, Figure 2 The B part in the compound 1-1 is a mass spectrum.

[0040] Figure 3 is the structural information of compound 1-2 in the synthesis process of the sorafenib-2C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 3 The A part in the compound 1-2 is 1 H-NMR spectrum, Figure 3 The B part in the compound 1-2 is a mass spectrum.

[0041] Figure 4is the structural information of compound 1-3 in the synthesis process of sorafenib-2C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 4 the A part in is the H-NMR spectrum of compound 1-3, 1 H-NMR spectrum, Figure 4 the B part in is the mass spectrum of compound 1-3.

[0042] Figure 5 is the structural information of compound 1-4 (sorafenib-2C-ursodeoxycholic acid conjugate prodrug compound) in the synthesis process of sorafenib-2C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 5 the A part in is the H-NMR spectrum of compound 1-4, 1 H-NMR spectrum, Figure 5 the B part in is the mass spectrum of compound 1-4.

[0043] Figure 6 is the synthesis route map of the sorafenib-2C-ursodeoxycholic acid conjugate prodrug compound of the present application.

[0044] Figure 7 is the structural information of compound 2-1 in the synthesis process of sorafenib-4C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 7 the A part in is the H-NMR spectrum of compound 2-1, 1 H-NMR spectrum, Figure 7 the B part in is the mass spectrum of compound 2-1.

[0045] Figure 8 is the structural information of compound 2-2 in the synthesis process of sorafenib-4C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 8 the A part in is the H-NMR spectrum of compound 2-2, 1 H-NMR spectrum, Figure 8 the B part in is the mass spectrum of compound 2-2.

[0046] Figure 9 is the structural information of compound 2-3 in the synthesis process of sorafenib-4C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 9 the A part in is the H-NMR spectrum of compound 2-3, 1 H-NMR spectrum, Figure 9 the B part in is the mass spectrum of compound 2-3.

[0047] Figure 10 is the structural information of compound 2-4 (sorafenib-4C-ursodeoxycholic acid conjugate prodrug compound) in the synthesis process of sorafenib-4C-ursodeoxycholic acid conjugate prodrug; wherein, Figure 10 the A part in is the H-NMR spectrum of compound 2-4, 1 H-NMR spectrum, Figure 10 the B part in is the mass spectrum of compound 2-4.

[0048] Figure 11 This is a synthetic route diagram of the sorafenib-10C-ursodeoxycholic acid conjugate prodrug compound of the present invention.

[0049] Figure 12 This provides structural information for compound 3-1 during the synthesis of the sorafenib-10C-ursodeoxycholic acid conjugate prodrug; among which, Figure 12 Part A in the text refers to compound 3-1. 1 H-NMR spectrum, Figure 12 Part B in the image is the mass spectrum of compound 3-1.

[0050] Figure 13 This provides structural information for compound 3-2 during the synthesis of the sorafenib-10C-ursodeoxycholic acid conjugate prodrug; among which, Figure 13 Part A in the text refers to compound 3-2. 1 H-NMR spectrum, Figure 13 Part B in the image is the mass spectrum of compound 3-2.

[0051] Figure 14 This provides the structural information of compound 3-3 during the synthesis of the sorafenib-10C-ursodeoxycholic acid conjugate prodrug; among which, Figure 14 Part A in the text refers to compound 3-3. 1 H-NMR spectrum, Figure 14 Part B in the image is the mass spectrum of compound 3-3.

[0052] Figure 15 This provides structural information for compounds 3-4 (sorafenib-10C-ursodeoxycholic acid conjugate prodrug compounds) during the synthesis of the sorafenib-10C-ursodeoxycholic acid conjugate prodrug; among them, Figure 15 Part A in the text refers to compounds 3-4. 1 H-NMR spectrum, Figure 15 Part B in the image shows the mass spectrum of compounds 3-4.

[0053] Figure 16 This is a characterization of the sorafenib-ursodeoxycholic acid conjugate prodrug compound; among which, Figure 16 Part A in the image is the Fourier transform infrared spectrum. Figure 16 Part B in the diagram is the powder X-ray diffraction pattern. Figure 16 Part C in the graph is the differential scanning calorimetry analysis chart. Figure 16 Part D in the image is a transmission scanning electron microscope (SEM) image.

[0054] Figure 17 The stability of the sorafenib-ursodeoxycholic acid conjugate prodrug at different pH values; among which, Figure 17 Part A in the equation has a pH of 1.0. Figure 17Part B in the equation has a pH of 4.0. Figure 17 The C portion of the solution has a pH of 7.2.

[0055] Figure 18 This is the equilibrium solubility diagram of the sorafenib-ursodeoxycholic acid conjugate prodrug at pH 7.2.

[0056] Figure 19 This is a graph showing the oil-water partition coefficients of the sorafenib-ursodeoxycholic acid conjugate prodrug.

[0057] Figure 20 This is a powder dissolution diagram of the sorafenib-ursodeoxycholic acid conjugate prodrug.

[0058] Figure 21 This is an in vivo drug metabolism diagram of the sorafenib-ursodeoxycholic acid conjugate prodrug compound. Detailed Implementation

[0059] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0060] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. The embodiments of this disclosure are not necessarily intended to encompass all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described below in more detail, can be implemented in any of a number of ways.

[0061] This invention uses sorafenib as a model drug, bile acid compounds as targets, and tert-butyl-(iodooxy)dimethylsilane as a linker to design and synthesize a universal method for sorafenib-chole acid prodrug conjugate prodrug.

[0062] In one preferred embodiment of the present invention, a method for preparing a sorafenib-cholic acid conjugate prodrug based on modular assembly of sorafenib is provided, comprising the following steps:

[0063] tert-butyl-(iodooxy)dimethylsilane is linked to the front end of sorafenib to obtain the first compound; wherein the structural formula of the first compound is shown in Formula I;

[0064]

[0065] The first compound is linked to the posterior end of sorafenib to obtain the second compound; wherein the structural formula of the second compound is shown in Formula II;

[0066]

[0067] The second compound undergoes de-TBSO to form an alcohol, yielding the third compound; the structural formula of the third-generation compound is shown in Formula III.

[0068]

[0069] The third compound is linked with a cholic acid compound to obtain a sorafenib-cholic acid conjugate prodrug; wherein the cholic acid compound is ursodeoxycholic acid, and the structural formula of the sorafenib-cholic acid conjugate prodrug is shown in Formula IV.

[0070]

[0071] In formulas I to IV, n = 2 to 10; TBSO: tert-butyldimethylsilyl.

[0072] In an optional example, tert-butyl-(iodooxy)dimethylsilane is linked to the sorafenib front end to obtain the first compound, which specifically includes the following steps:

[0073] At room temperature, the sorafenib front end (4-(4-aminophenoxy)-N-methyl-2-pyridinecarboxamide) was dissolved in anhydrous acetonitrile, and tert-butyl-(iodooxy)dimethylsilane, potassium carbonate and sodium iodide were added in sequence. After the addition was completed, the mixture was transferred to 90°C and the reaction was stirred.

[0074] After the reaction was completed, the reaction solution was cooled to room temperature and then subjected to reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product to obtain the first compound.

[0075] In a further preferred example, the equivalent ratio of the sorafenib tip, tert-butyl-(iodooxy)dimethylsilane, potassium carbonate, and sodium iodide is 1:3:3:0.3 to 1:5:5:1, and is particularly preferred to be 1:3:3:0.3.

[0076] In another preferred example, tert-butyl-(iodooxy)dimethylsilane includes tert-butyl-(2-iodoethoxy)dimethylsilane, tert-butyl-(4-iodobutoxy)dimethylsilane, or tert-butyl-(10-iododecoxy)dimethylsilane; it is understood that other C-chain structures of different lengths may also be used.

[0077] In an optional example, the first compound is linked to the back end of sorafenib to obtain the second compound, specifically including the following steps:

[0078] At room temperature, the first compound was dissolved in anhydrous dichloromethane, and the sorafenib back-end (4-chloro-3-trifluoromethyl isocyanate phenyl ester) and triethylamine were added sequentially. After the addition was complete, the reaction was continued with stirring at room temperature.

[0079] After the reaction was completed, the second compound was obtained through reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product.

[0080] In a further preferred example, the equivalent ratio of the first compound, the sorafenib tail end, and triethylamine is 1:4:5 to 1:5:8, and is particularly preferred to be 1:4:5.

[0081] In an optional example, the second compound is de-TBSOd to ​​an alcohol to obtain the third compound, specifically including the following steps:

[0082] At room temperature, the second compound was dissolved in anhydrous dichloromethane, tetrabutylammonium fluoride was added, and the reaction was continued with stirring at room temperature after the addition was completed.

[0083] After the reaction was completed, the third compound was obtained through reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product.

[0084] In a further preferred example, the equivalent ratio of the second compound to tetrabutylammonium fluoride is 1:2 to 1:5, and particularly preferably 1:2.

[0085] In an optional example, the third compound is linked with a bile acid compound to obtain a fourth compound, specifically including the following steps:

[0086] At room temperature, the third compound, bile acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine were simultaneously dissolved in anhydrous DMF, and the reaction was continued with stirring at room temperature.

[0087] After the reaction was completed, the sorafenib-cholic acid conjugate prodrug was obtained through reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product.

[0088] In a further preferred example, the equivalent ratio of the third compound, the cholic acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine is 1:2:4:1 to 1:5:5:3, and is particularly preferred to be 1:2:4:1; it is understood that the cholic acid compound can also be other types of cholic acid in principle, such as deoxycholic acid, chenodeoxycholic acid, etc.

[0089] The present invention provides an exemplary method for preparing a sorafenib-cholic acid conjugate prodrug compound, comprising the following specific steps:

[0090] S1: Linking the sorafenib terminus with the linker intermediate: At room temperature, the sorafenib terminus was dissolved in anhydrous acetonitrile (20 mL), and tert-butyl-(iodooxy)dimethylsilane, potassium carbonate, and sodium iodide were added sequentially (the equivalent ratio of sorafenib terminus, tert-butyl-(iodooxy)dimethylsilane, potassium carbonate, and sodium iodide was 1:3:3:0.3). After the addition was complete, the mixture was transferred to 90 °C and stirred for 16 hours. The reaction solution was cooled to room temperature and the reaction was quenched with water.

[0091] The extract was extracted twice with ethyl acetate, the organic phase was washed with saturated sodium chloride aqueous solution, dried with anhydrous sodium sulfate, filtered, and the filtrate was purified by vacuum distillation at 30°C to obtain a yellow oily product, namely the first compound.

[0092] S2: First compound linked to the sorafenib end: At room temperature, the first compound was dissolved in anhydrous dichloromethane, and the sorafenib end and triethylamine were added sequentially (the equivalent ratio of the first compound, the sorafenib end and triethylamine was 1:4:5). After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water.

[0093] The product was extracted twice with dichloromethane, the organic phase was washed with saturated sodium chloride aqueous solution, dried with anhydrous sodium sulfate, filtered, and the filtrate was purified by vacuum distillation at 30°C to obtain a white solid product, namely the second compound.

[0094] S3: The second compound is de-TBSO-reduced to alcohol: At room temperature, the second compound is dissolved in anhydrous dichloromethane, and tetrabutylammonium fluoride (the equivalent ratio of the second compound to tetrabutylammonium fluoride is 1:2) is added. After the addition is complete, the mixture is stirred at room temperature for 2 hours, and the reaction is quenched with water.

[0095] The product was extracted twice with dichloromethane, the organic phase was washed with saturated sodium chloride aqueous solution, dried with anhydrous sodium sulfate, filtered, and the filtrate was purified by vacuum distillation at 30°C to obtain a white solid product, namely the third compound.

[0096] S4: Third compound linked to ursodeoxycholic acid: At room temperature, the third compound, cholic acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine were simultaneously dissolved in anhydrous DMF (the equivalent ratio of the third compound, cholic acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine was 1:2:4:1), and the mixture was stirred at room temperature for 16 hours. The reaction was then quenched with water.

[0097] The extract was extracted twice with ethyl acetate, the organic phase was washed with saturated sodium chloride aqueous solution, dried with anhydrous sodium sulfate, filtered, and the filtrate was purified by vacuum distillation at 30°C to obtain a white solid product, namely sorafenib-cholic acid conjugate prodrug.

[0098] In another embodiment of the present invention, a sorafenib-cholic acid conjugate prodrug prepared by the aforementioned method is also provided, with a high total yield. Its structural formula is shown in Formula IV. After entering the intestine, the synthesized sorafenib-cholic acid conjugate prodrug compound can be effectively transported into the blood by the ASBT protein, thereby improving the drug's permeability and increasing the blood drug concentration. This, in turn, improves the drug's bioavailability and anti-hepatocellular carcinoma effect, achieving the prevention and treatment of chronic liver cancer.

[0099] To facilitate better understanding, the present invention will be further illustrated below with several specific examples, but the preparation process is not limited to these examples, and the content of the present invention is not limited to these examples.

[0100] Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0101] Example 1

[0102] This example uses ursodeoxycholic acid (UDCA) and tert-butyl-(2-iodoethoxy)dimethylsilane to synthesize the sorafenib-2C-ursodeoxycholic acid conjugate prodrug compound (SOR-2C-UDCA); the synthetic route of the sorafenib-2C-ursodeoxycholic acid conjugate prodrug compound (SOR-2C-UDCA) is as follows: Figure 1 As shown, the specific implementation steps are as follows:

[0103] S1: Linker intermediate linking sorafenib terminus: At room temperature, the sorafenib terminus (1.00 g, 4.14 mmol, 1.0 equ.) was dissolved in anhydrous acetonitrile (20 mL), and tert-butyl-(2-iodoethoxy)dimethylsilane (3.55 g, 12.42 mmol, 3.0 equ.), potassium carbonate (1.72 g, 12.42 mmol, 3.0 equ.), and sodium iodide (0.19 g, 1.24 mmol, 0.3 equ.) were added sequentially. After the addition was complete, the mixture was transferred to 90 °C and stirred for 16 hours. The reaction solution was cooled to room temperature, and the reaction was quenched with water (50 mL).

[0104] Extracted twice with ethyl acetate (50 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a yellow oily product (yield: 39.4%), namely compound 1-1.

[0105] S2: Compound 1-1 linked to the sorafenib end: At room temperature, compound 1-1 (0.65 g, 1.62 mmol, 1.0 equ.) was dissolved in anhydrous dichloromethane (10 mL), and the sorafenib end (1.43 g, 6.48 mmol, 4.0 equ.) and triethylamine (0.82 g, 8.10 mmol, 5.0 equ.) were added sequentially. After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water (20 mL).

[0106] Extracted twice with dichloromethane (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 67.5%), namely compounds 1-2.

[0107] S3: Compound 1-2 de-TBSO to alcohol: At room temperature, compound 1-2 (0.68 g, 1.09 mmol, 1.0 equ.) was dissolved in anhydrous dichloromethane (10 mL), and tetrabutylammonium fluoride (2.18 mL, 2.18 mmol, 2.0 equ.) was added. After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water (20 mL).

[0108] Extracted twice with dichloromethane (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 75.5%), namely compounds 1-3.

[0109] S4: Compounds 1-3 linked to ursodeoxycholic acid: At room temperature, compounds 1-3 (0.42 g, 0.83 mmol, 1.0 equ.), ursodeoxycholic acid (0.65 g, 1.66 mmol, 2.0 equ.), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.52 g, 3.32 mmol, 4.0 equ.), and 4-dimethylaminopyridine (0.10 g, 0.83 mmol, 1.0 equ.) were dissolved in anhydrous DMF (5 mL), and the mixture was stirred at room temperature for 16 hours. The reaction was then quenched with water (20 mL).

[0110] The extract was extracted twice with ethyl acetate (20 mL × 2). The organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 40.2%), namely compounds 1-4, namely sorafenib-2C-ursodeoxycholic acid conjugate prodrug compound (overall yield: 8.07%).

[0111] The structures of the compounds synthesized in different steps in Example 1 were determined by mass spectrometry and proton nuclear magnetic resonance spectroscopy.

[0112] The structural information of compound 1-1 is as follows: Figure 2 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0113] 1H NMR(400MHz, DMSO-d6)δ8.78–8.69(m,1H),8.45(d,J=5.6Hz,1H),7.35(d,J=2.6Hz,1H),7.12–7.01(m,1H),6.98–6.87(m,2H), 6.73–6.63(m,2H),5.74–5.60(m,1H),3.79–3.68(m,2H),3.19–3.17(m,2H),2.86–2.72(m,3H),0.88(s,9H),0.09–0.01(m,6H).

[0114] The mass spectrometry results are MS (ESI) m / z of C. 21 H 31 N3O3Si, [M+H] + =402.50.

[0115] Structural information of compounds 1-2 is as follows Figure 3 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0116] 1 H NMR(400MHz, DMSO-d6)δ8.83–8.73(m,1H),8.61(s,1H),8.55(d,J=5.6Hz,1H),8.08–8.01(m,1H),7.83–7.76(m,1H),7.60–7.54(m, 2H),7.52–7.42(m,2H),7.33–7.24(m,2H),7.24–7.18(m,1H),3.90–3.71(m,4H),2.86–2.75(m,3H),0.84(s,9H),0.04–0.00(m,6H).

[0117] The mass spectrometry results are MS (ESI) m / z of C. 29 H 34 N4O4ClF3Si, [M+H] + =623.60.

[0118] Structural information of compounds 1-3 is as follows Figure 4 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0119] 1H NMR(400MHz, DMSO-d6)δ8.00–7.89(m,1H),7.77(s,1H),7.70(d,J=5.6Hz,1H),7.25–7.14(m,1H),6.98–6.85(m,1H) ,6.77–6.60(m,4H),6.45–6.31(m,3H),4.15–4.02(m,1H),2.94–2.87(m,2H),2.73–2.69(m,2H),2.01–1.90(m,3H).

[0120] The mass spectrometry results are MS (ESI) m / z of C. 23 H 20 N4O4ClF3, [M+H] + =509.50.

[0121] The structural information of compounds 1-4 (sorafenib-2C-ursodeoxycholic acid conjugate prodrug compounds) is as follows: Figure 5 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0122] 1 H NMR(400MHz, DMSO-d6)δ8.87–8.70(m,1H),8.61(s,1H),8.57(d,J=5.6Hz,1H),8.13–8.03(m,1H),7.86–7.76(m,1 H),7.60–7.53(m,2H),7.51–7.44(m,2H),7.35–7.26(m,2H),7.27–7.19(m,1H),4.49–4.41(m,1H),4.26–4.14(m,2 H),4.04–3.89(m,2H),3.86–3.78(m,1H),3.27–3.18(m,1H),2.89–2.74(m,3H),2.25–2.14(m,1H),2.13–2.02(m, 1H),1.86–1.72(m,2H),1.70–1.56(m,4H),1.52–1.06(m,15H),1.04–0.89(m,3H),0.88–0.77(m,7H),0.53(s,3H).

[0123] The mass spectrometry results are MS (ESI) m / z of C. 47 H 58 O7N4F3Cl, [M+H] + =883.80.

[0124] Example 2

[0125] This example uses ursodeoxycholic acid (UDCA) and tert-butyl(4-iodobutoxy)dimethylsilane to synthesize the sorafenib-4C-ursodeoxycholic acid conjugate prodrug compound (SOR-4C-UDCA); the synthetic steps of the sorafenib-4C-ursodeoxycholic acid conjugate prodrug compound (SOR-4C-UDCA) are as follows: Figure 6 As shown, the specific implementation steps are as follows:

[0126] S1: Linker intermediate linking sorafenib terminus: At room temperature, the sorafenib terminus (1.00 g, 4.14 mmol, 1.0 equ.) was dissolved in anhydrous acetonitrile (20 mL), and tert-butyl(4-iodobutoxy)dimethylsilane (3.90 g, 12.42 mmol, 3.0 equ.), potassium carbonate (1.72 g, 12.42 mmol, 3.0 equ.), and sodium iodide (0.19 g, 1.24 mmol, 0.3 equ.) were added sequentially. After the addition was complete, the mixture was transferred to 90 °C and stirred for 16 hours. The reaction solution was cooled to room temperature, and the reaction was quenched with water (50 mL).

[0127] Extracted twice with ethyl acetate (50 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a yellow oily product (yield: 41.9%), namely compound 2-1.

[0128] S2: Compound 2-1 linked to the sorafenib end: At room temperature, compound 2-1 (0.74 g, 1.73 mmol, 1.0 equ.) was dissolved in anhydrous dichloromethane (10 mL), and the sorafenib end (1.54 g, 6.92 mmol, 4.0 equ.) and triethylamine (0.88 g, 8.65 mmol, 5.0 equ.) were added sequentially. After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water (20 mL).

[0129] Extracted twice with dichloromethane (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 74.0%), namely compound 2-2.

[0130] S3: Compound 2-2 de-TBSO to alcohol: At room temperature, compound 2-2 (0.83 g, 1.28 mmol, 1.0 equ.) was dissolved in anhydrous dichloromethane (10 mL), and tetrabutylammonium fluoride (2.56 mL, 2.56 mmol, 2.0 equ.) was added. After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water (20 mL).

[0131] Extracted twice with dichloromethane (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 73.1%), namely compound 2-3.

[0132] S4: Compound 2-3 linked to ursodeoxycholic acid: At room temperature, compounds 2-3 (0.50 g, 0.93 mmol, 1.0 equ.), ursodeoxycholic acid (0.73 g, 1.86 mmol, 2.0 equ.), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.58 g, 3.72 mmol, 4.0 equ.), and 4-dimethylaminopyridine (0.12 g, 0.47 mmol, 1.0 equ.) were dissolved in anhydrous DMF (5 mL), and the mixture was stirred at room temperature for 16 hours. The reaction was then quenched with water (20 mL).

[0133] Extracted twice with ethyl acetate (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 35.5%), namely compound 2-4, namely sorafenib-4C-ursodeoxycholic acid conjugate prodrug compound (overall yield: 8.05%).

[0134] The structures of the compounds synthesized in different steps in Example 2 were determined by mass spectrometry and proton nuclear magnetic resonance spectroscopy.

[0135] The structural information of compound 2-1 is as follows: Figure 7 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0136] 1 H NMR (400MHz, DMSO-d6) δ8.76–8.62(m,1H),8.46–8.30(m,1H),7.37–7.26(m,1H),7.08–7.00(m,1H),6.92–6.83(m,2H),6.66–6.55(m,2H ),5.71–5.64(m,1H),3.65–3.55(m,2H),3.04–2.92(m,2H),2.79–2.71(m,3H),1.67–1.45(m,4H),0.89–0.77(m,9H),0.07–0.01(m,6H).

[0137] The mass spectrometry results are MS (ESI) m / z of C. 23 H 35 N3O3Si, [M+H] + =430.40.

[0138] Structural information of compound 2-2 is as follows Figure 8 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0139] 1 H NMR(400MHz, DMSO-d6)δ8.85–8.72(m,1H),8.61–8.47(m,2H),8.08–8.03(m,1H),7.83–7.76(m,1H),7.60–7.53(m,2H),7.48–7.41(m,2H),7.3 2–7.26(m,2H),7.24–7.17(m,1H),3.78–3.68(m,2H),3.62–3.54(m,2H) ,2.88–2.75(m,3H),1.60–1.44(m,4H),0.85–0.80(m,9H),0.00(s,6H).

[0140] The mass spectrometry results are MS (ESI) m / z of C. 31 H 38 N4O4ClF3Si, [M+H] + =651.60.

[0141] Structural information of compounds 2-3 is as follows Figure 9 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0142] 1 H NMR (400MHz, DMSO-d6) δ8.85–8.74(m,1H),8.60–8.48(m,2H),8.05(d,J=2.6Hz,1H),7.84–7.75(m,1H),7.59–7.52(m,2H),7.49–7.40(m,2H ),7.33–7.26(m,2H),7.24–7.19(m,1H),4.44–4.37(m,1H),3.76–3.62(m,2H),3.44–3.35(m,2H),2.80(d,J=4.8Hz,3H),1.58–1.40(m,4H).

[0143] The mass spectrometry results are MS (ESI) m / z of C. 25 H 24 N4O4ClF3, [M+H] + =537.00.

[0144] The structural information of compounds 2-4 (sorafenib-4C-ursodeoxycholic acid conjugate prodrug compound) is as follows: Figure 10 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0145] 1 H NMR(400MHz, DMSO-d6)δ8.87–8.74(m,1H),8.56(d,J=5.6Hz,1H),8.52(s,1H),8.09–8.00(m,1H),7.84–7.75(m,1H),7.58–7 .53(m,2H),7.47–7.42(m,2H),7.33–7.26(m,2H),7.25–7.20(m,1H),4.47–4.42(m,1H),4.07–3.96(m,2H),3.88–3.80(m,1H) ,3.78–3.65(m,2H),3.28–3.23(m,1H),2.85–2.77(m,3H),2.32–2.23(m,1H),2.21–2.11(m,1H),1.89–1.78(m,2H),1.74–1. 50(m,9H),1.49–1.42(m,3H),1.40–1.26(m,7H),1.19–1.04(m,6H),0.97–0.89(m,2H),0.86–0.81(m,6H),0.60–0.51(m,3H).

[0146] The mass spectrometry results are MS (ESI) m / z of C. 49 H 62 O7N4F3Cl, [M+H] + =911.90.

[0147] Example 3

[0148] This example uses ursodeoxycholic acid (UDCA) and tert-butyl(10-iododecoxy)dimethylsilane to synthesize the sorafenib-10C-ursodeoxycholic acid conjugate prodrug compound (SOR-10C-UDCA); the synthetic steps of the sorafenib-10C-ursodeoxycholic acid conjugate prodrug compound (SOR-10C-UDCA) are as follows: Figure 11 As shown, the specific implementation steps are as follows:

[0149] S1: Linking the sorafenib terminus with the linker intermediate: At room temperature, the sorafenib terminus (1.00 g, 4.14 mmol, 1.0 equ.) was dissolved in anhydrous acetonitrile (20 mL), followed by the addition of tert-butyl(10-iododecoxy)dimethylsilane (4.94 g, 12.42 mmol, 3.0 equ.), potassium carbonate (1.72 g, 12.42 mmol, 3.0 equ.), and sodium iodide (0.19 g, 1.24 mmol, 0.3 equ.). After the addition was complete, the mixture was transferred to 90 °C and stirred for 16 hours. The reaction solution was then cooled to room temperature, and the reaction was quenched with water (50 mL).

[0150] Extracted twice with ethyl acetate (50 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a yellow oily product (yield: 42.2%), namely compound 3-1.

[0151] S2: Compound 3-1 linked to the sorafenib end: At room temperature, compound 3-1 (0.89 g, 1.73 mmol, 1.0 equ.) was dissolved in anhydrous dichloromethane (10 mL), and the sorafenib end (1.54 g, 6.92 mmol, 4.0 equ.) and triethylamine (0.88 g, 8.65 mmol, 5.0 equ.) were added sequentially. After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water (20 mL).

[0152] Extracted twice with dichloromethane (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 73.1%), namely compound 3-2.

[0153] S3: Compound 3-2 de-TBSO to alcohol: At room temperature, compound 3-2 (0.93 g, 1.27 mmol, 1.0 equ.) was dissolved in anhydrous dichloromethane (10 mL), and tetrabutylammonium fluoride (2.56 mL, 2.56 mmol, 2.0 equ.) was added. After the addition was complete, the mixture was stirred at room temperature for 2 hours, and the reaction was quenched with water (20 mL).

[0154] Extracted twice with dichloromethane (20 mL × 2), the organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 73.5%), namely compound 3-3.

[0155] S4: Compound 3-3 linked to ursodeoxycholic acid: At room temperature, compound 3-3 (0.58 g, 0.93 mmol, 1.0 equ.), ursodeoxycholic acid (0.73 g, 1.86 mmol, 2.0 equ.), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.58 g, 3.72 mmol, 4.0 equ.), and 4-dimethylaminopyridine (0.12 g, 0.47 mmol, 1.0 equ.) were dissolved in anhydrous DMF (5 mL), and the mixture was stirred at room temperature for 16 hours. The reaction was then quenched with water (20 mL).

[0156] The extract was extracted twice with ethyl acetate (20 mL × 2). The organic phase was washed with saturated sodium chloride aqueous solution (50 mL), dried with anhydrous sodium sulfate, filtered, and the filtrate was vacuum distilled at 30 °C to purify the crude product, yielding a white solid product (yield: 35.5%), namely compound 3-4, namely sorafenib-10C-ursodeoxycholic acid conjugate prodrug compound (overall yield: 8.05%).

[0157] The structures of the compounds synthesized in different steps in Example 2 were determined by mass spectrometry and proton nuclear magnetic resonance spectroscopy.

[0158] Structural information of compound 3-1 is as follows Figure 12 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0159] 1 H NMR(400MHz, CDCl3)δ8.33(d,J=5.6Hz,1H),8.08–7.93(m,1H),7.76–7.58(m ,1H),7.26(s,1H),6.99–6.83(m,3H),6.65(d,J=8.8Hz,2H),3.60(t,J=6.6H z,2H),3.11(t,J=7.2Hz,2H),3.06–2.96(m,3H),1.69–1.61(m,2H),1.54–1. 47(m,2H),1.45–1.38(m,2H),1.30(s,10H),0.94–0.87(m,9H),0.05(s,6H).

[0160] The mass spectrometry results are MS (ESI) m / z of C. 29 H 47 N3O3Si, [M+H] + =514.50.

[0161] Structural information of compound 3-2 is as follows Figure 13 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0162] 1H NMR (400MHz, CDCl3) δ8.49(d,J=5.6Hz,1H),8.17(s,1H),7.82(d,J=2.4Hz,1H),7.6 9(d,J=2.6Hz,1H),7.55–7.46(m,1H),7.42–7.32(m,3H),7.26–7.21(m,2H),7.17–7 .11(m,1H),6.24(s,1H),3.80–3.67(m,2H),3.62–3.53(m,2H),3.08–2.97(m,3H),1 .60(s,2H),1.53–1.46(m,2H),1.34–1.26(m,12H),0.92–0.84(m,9H),0.04(s,6H).

[0163] The mass spectrometry results are MS (ESI) m / z of C. 37 H 50 N4O4ClF3Si, [M+H] + =735.60.

[0164] Structural information of compound 3-3 is as follows Figure 14 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0165] 1 H NMR (400MHz, CDCl3) δ8.52–8.42(m,1H),8.10(d,J=3.8Hz,1H),7.79(d,J=2.4Hz,1H),7.73–7.66(m,1H),7.55–7.45(m,1H),7.42–7.31(m,3H),7. 26–7.19(m,2H),7.16–7.05(m,1H),6.30(s,1H),3.79–3.68(m,2H),3.67 –3.57(m,2H),3.09–2.98(m,3H),1.64–1.52(m,4H),1.37–1.26(m,12H).

[0166] The mass spectrometry results are MS (ESI) m / z of C. 31 H 36 N4O4ClF3, [M+H] + =621.50.

[0167] The structural information of compounds 3-4 (sorafenib-10C-ursodeoxycholic acid conjugate prodrug compound) is as follows: Figure 15 As shown, the results of the hydrogen NMR spectrum analysis are as follows:

[0168] 1H NMR(400MHz, DMSO-d6)δ8.85–8.74(m,1H),8.55(d,J=5.6Hz,1H),8.50(s,1H),8.11–8.01(m,1H),7.85–7.73(m,1H), 7.63–7.52(m,2H),7.44(d,J=8.8Hz,2H),7.28(d,J=8.8Hz,2H),7.24–7.19(m,1H),4.50–4.38(m,1H),4.04–3.93(m, 2H),3.89–3.82(m,1H),3.75–3.61(m,2H),3.31–3.21(m,2H),2.86–2.73(m,3H),2.36–2.25(m,1H),2.23–2.14(m,1H ),1.92–1.63(m,6H),1.54–1.42(m,7H),1.39–1.20(m,20H),1.19–1.00(m,6H),0.96–0.84(m,7H),0.65–0.55(m,3H).

[0169] The mass spectrometry results are MS (ESI) m / z of C. 55 H 74 O7N4F3Cl, [M+H] + =995.30.

[0170] The prodrugs linked by C chains of different lengths will be collectively referred to as SOR-UDCA conjugate prodrugs.

[0171] Example 4

[0172] Characterization of the SOR-UDCA conjugate prodrug

[0173] (1) Fourier transform infrared spectroscopy (FT-IR)

[0174] Appropriate amounts of SOR, UDCA, and different SOR-UDCA powder samples were placed at room temperature and vacuum dried for 24 hours to remove moisture. The samples were then mixed thoroughly with potassium bromide, pressed into pellets, and analyzed by Fourier transform infrared spectroscopy (FT-IR); the spectral resolution was 4 cm⁻¹. -1 The detection wavelength is 4000–400 cm⁻¹ -1 The result is as follows Figure 16 As shown in Part A of the document.

[0175] As can be seen from the figure, compared with SOR, the SOR-UDCA conjugate prodrug has a lower concentration at 2823 cm⁻¹. -1There is a CH vibration peak at this location, which is the same as the CH vibration peak in UDCA; compared with UDCA, the SOR-UDCA conjugate prodrug has a peak at 1672 cm⁻¹. -1 The presence of a CO-NH vibrational peak at this location corresponds to the CO-NH vibrational peak in SOR. This indicates that the SOR-UDCA conjugate prodrug was successfully synthesized.

[0176] (2) Powder X-ray diffraction (PXRD)

[0177] Appropriate amounts of SOR, UDCA, and different SOR-UDCA sample powders were taken and measured using a powder X-ray diffractometer with a Cu-Kα target. The scanning range was 2θ = 5° - 35°, the scanning step size was 0.01° / 2θ, and the scanning speed was 1° / min. The results are as follows: Figure 16 As shown in part B of the document.

[0178] As can be seen from the figure, the SOR drug crystal has characteristic diffraction peaks at 11.4°, 18.62°, 22.5°, 22.94°, and 24.78°; while the SOR-UDCA sample has no obvious characteristic diffraction peaks; this indicates that the prepared sorafenib-ursodeoxycholic acid conjugate prodrug compound is in an amorphous state.

[0179] (3) Modulation differential scanning calorimetry

[0180] A 10.00 mg sample was placed in an aluminum pot. First, the sample was heated from 20°C to 250°C at a rate of 10°C / min, and allowed to equilibrate for 5 minutes. Then, the sample was cooled from 250°C to -80°C at a rate of 40°C / min, with a nitrogen flow rate of 50 mL / min. Finally, the sample was heated from -80°C to 250°C at a rate of 20°C / min. Results... Figure 16 As shown in section C.

[0181] As shown in the figure, crystalline SOR exhibits a distinct endothermic peak at 202.00℃, which is the melting point peak of SOR; UDCA also exhibits a distinct endothermic peak at 203.24℃, which is the melting point peak of UDCA; these results indicate that SOR and UDCA are crystalline. In contrast, the three SOR-UDCA types do not show obvious characteristic absorption peaks; they all exhibit a typical S-shaped step transition temperature, which is typical of glass transition temperatures, at 99.0℃ (SOR-2C-UDCA), 75.2℃ (SOR-4C-UDCA), and 84.2℃ (SOR-10C-UDCA), respectively; these results indicate that SOR-UDCA is amorphous.

[0182] (4) Scanning Electron Microscope (SEM) analysis

[0183] Appropriate amounts of SOR, UDCA, and different SOR-UDCA sample powders were taken and dried in a vacuum drying oven to remove moisture. Then, the SOR, UDCA, and different SOR-UDCA sample powders were adhered to a copper stage and sputter-coated with gold for 3 minutes at a working voltage of 5 kV. Finally, the morphological and structural characteristics of the samples were observed. The results are as follows: Figure 16 As shown in part D of the diagram.

[0184] As can be seen from the figure, SOR and UDCA have regular blocky structures. The structures of the three SOR-UDCA conjugate prodrugs have changed significantly. Among them, SOR-2C-UDCA and SOR-4C-UDCA have obvious network structures, while SOR-10C-UDCA is spherical.

[0185] Powder X-ray diffraction and differential scanning calorimetry showed that the prepared sorafenib-ursodeoxycholic acid conjugate prodrug was an amorphous, non-crystalline compound, indicating that SOR-UDCA has the ability to increase drug dissolution.

[0186] Example 5

[0187] [Stability Study of SOR-UDCA Conjugate Prodrug in Solutions with Different pH Values]

[0188] Accurately weigh 1.0 mg of SOR-UDCA prodrug and dissolve it in 1.0 mL of methanol to prepare a stock solution with a concentration of 1.00 mg / mL. Add 9.0 mL of solutions with different pH values ​​(1.0, 4.0, 7.2) containing 10% methanol. Take 0.5 mL samples every 15, 30, 60, 90, 120, and 240 min for each sample. Analyze the SOR-UDCA prodrug concentration using high-performance liquid chromatography (HPLC). The results are shown below. Figure 17 As shown.

[0189] As can be seen from the figure, when the drug is in a solution with pH = 1.0 ( Figure 17(Part A of the diagram) The concentrations of the three SOR-UDCA prodrugs decreased rapidly over time, indicating that the drugs are unstable in a strongly acidic environment (pH=1.0). Furthermore, the stability of the three SOR-UDCA prodrugs in a strongly acidic environment (pH=1.0) also differed: SOR-4C-UDCA prodrug decomposed completely in 0.5 h; SOR-10C-UDCA prodrug decomposed completely in 1.5 h; while SOR-2C-UDCA prodrug decomposed completely in 2.0 h. The results show that the stability of the three SOR-UDCA prodrugs in a strongly acidic environment (pH=1.0) is: SOR-2C-UDCA > SOR-10C-UDCA > SOR-4C-UDCA.

[0190] When the drug is in a solution with pH = 4.0 ( Figure 17 (Part B of the table) The concentrations of the three SOR-UDCA prodrugs gradually decreased over time, indicating that the drugs are unstable in an acidic environment (pH=4.0). Furthermore, the stability of the three SOR-UDCA prodrugs in an acidic environment (pH=4.0) also differed. For SOR-4C-UDCA prodrug, the drug was almost completely decomposed at 1.5 h (2.94±0.85) and completely decomposed at 4.0 h (0.00±0.00). For SOR-10C-UDCA prodrug, the drug was almost completely decomposed at 2.0 h (5.33±1.23) μg / mL and almost completely decomposed at 4.0 h (2.40±0.94) μg / mL. However, for SOR-2C-UDCA prodrug, the drug was not completely decomposed at 4.0 h (9.00±2.64) μg / mL. The results showed that the stability of the three SOR-UDCA prodrugs in an acidic environment (pH=4.0) was: SOR-2C-UDCA>SOR-10C-UDCA>SOR-4C-UDCA.

[0191] When the drug is in a solution with pH = 7.2 ( Figure 17 (Part C of the diagram) The concentrations of the three SOR-UDCA prodrugs decreased slowly over time. At 4.0 h, the concentrations of the three SOR-UDCA prodrugs in a weakly alkaline environment (pH = 7.2) were: SOR-2C-UDCA (92.41 ± 1.51) μg / mL > SOR-10C-UDCA (88.69 ± 0.68) μg / mL > SOR-4C-UDCA (82.53 ± 2.17) μg / mL. The results indicate that the three SOR-UDCA prodrugs are generally stable in a weakly alkaline environment (pH = 7.2), and their stability is in the order of SOR-2C-UDCA > SOR-10C-UDCA > SOR-4C-UDCA.

[0192] In summary, the three SOR-UDCA prodrugs are unstable in acidic environments but basically stable in weakly alkaline environments, with SOR-2C-UDCA being the most stable, possibly due to the greater steric hindrance of the 2C group.

[0193] The above results indicate that the SOR-UDCA prodrug can be degraded in the acidic environment of the tumor, thereby releasing the model drug sorafenib and achieving precise targeting of the model drug; while in a weakly alkaline environment, the SOR-UDCA prodrug remains basically stable, indicating that the SOR-UDCA prodrug can remain stable in the blood (pH=7.2), thereby effectively reaching the liver and achieving liver targeting.

[0194] Example 6

[0195] [Stability and Equilibrium Solubility Studies of SOR-UDCA Conjugate Prodrug in Solution at pH 7.2]

[0196] Take 5.0 mL of PBS solution and excess drug into sealed vials, sonicate for 30 min, and shake at a constant temperature of 37℃ for 24 h. Take the supernatant at 13000 rpm. -1 After centrifugation for 5.0 min, filtration through a 0.22 μm microporous membrane, and appropriate dilution with methanol, the drug content was determined by high-performance liquid chromatography (HPLC). The results are as follows: Figure 18 As shown.

[0197] As shown in the figure, the equilibrium solubility of SOR is (2.70±0.46 μg / mL). The equilibrium solubilities of the three SOR-UDCA prodrugs are SOR-2C-UDCA (8.00±1.70) μg / mL, SOR-10C-UDCA (13.52±2.57) μg / mL, and SOR-4C-UDCA (4.67±0.87) μg / mL, respectively. Compared with SOR, the equilibrium solubility of the three SOR-UDCA prodrugs increases.

[0198] The above results indicate that all three SOR-UDCA prodrugs can increase the equilibrium solubility of the drug, laying the foundation for improving the bioavailability of the drug.

[0199] Example 7

[0200] [Study on the oil-water partition coefficient of SOR-UDCA conjugate prodrug]

[0201] Select an appropriate amount of n-octanol and mix it with a phosphate buffer solution at pH 7.2. Place the mixture in a water bath shaker at 37°C for 24 hours. Transfer the mixture to a separatory funnel and let it stand for 24 hours. Separate the upper and lower layers to obtain an octanol phase saturated with pH 7.2 and an aqueous phase saturated with n-octanol, and store them for later use. Weigh an excess of the drug and place it in a 10 mL volumetric flask. Add the octanol phase saturated with pH 7.2 and the aqueous phase saturated with n-octanol, respectively. Place the test tube in a 37°C water bath shaker and shake for 24 hours until equilibrium is reached. Separate the lower aqueous phase, filter it through a 0.45 μm microporous membrane, and collect the filtrate for HPLC analysis. Determine the concentration of each component and calculate the oil-water partition coefficient (Log P) of the drug according to Formula 1. The results are as follows: Figure 19 As shown.

[0202] Log P = log(C 正辛醇 / C 水 )1

[0203] In the formula C 正辛醇 The concentration of the substance in molecular form in the n-octanol phase (μg·mL) -1 );C 水 The concentration of a substance in its molecular state in the aqueous phase (μg·mL) -1 ).

[0204] As shown in the figure, compared with SOR, the Log P values ​​of the three SOR-UDCA prodrugs all decreased, and increased sequentially with the increase of the linker (C chain length). This may be related to the Log P value of the target (ursodeoxycholic acid). After linking sorafenib (Log P = 6.08) with ursodeoxycholic acid (Log P = 3.08), the Log P value of the prodrug was balanced, falling between the Log P values ​​of the drug and the target.

[0205] The above results indicate that all three SOR-UDCA prodrugs reduce the drug's lipid solubility, which in turn increases its water solubility, making it easier to cross the intestinal mucus barrier, thereby improving drug permeability and bioavailability.

[0206] Example 8

[0207] [Powder dissolution study of SOR-UDCA conjugate prodrug]

[0208] Accurately weigh 10.00 mg of different samples (SOR, SOR-2C-UDCA, SOR-4C-UDCA, SOR-10C-UDCA) and place them in 900 mL of phosphate buffer (pH = 7.2, 0.5% SDS). Stir at 150 rpm for 2.0 mL at 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min. After each sampling, add an equal volume of isothermal dissolution medium. Centrifuge the samples at 13000 rpm for 3.0 min. Dilute the supernatant 5-fold with methanol, filter through a 0.22 μm filter, and determine the drug content using HPLC. The results are shown below. Figure 20 As shown.

[0209] As shown in the figure, compared with SOR, the cumulative dissolution percentages of the three SOR-UDCA prodrugs were all increased. This may be the result of the combined effect of the amorphous state and reduced particle size of the prodrugs themselves. Therefore, the reduction in drug crystal particle size and the change in crystal state are beneficial to improving drug dissolution. At 4 h, compared with pure SOR crystal raw material (27.03±2.70%), the cumulative dissolution percentages of the three SOR-UDCA prodrugs were SOR-10C-UDCA (87.84±2.67%) > SOR-4C-UDCA (78.85±3.56%) > SOR-2C-UDCA (65.64±6.02%), which were 3.25, 2.92, and 2.43 times higher, respectively.

[0210] The above results indicate that the SOR-UDCA prodrug synthesized by the method of the present invention can increase the drug dissolution rate.

[0211] Example 9

[0212] [In vivo pharmacokinetic study of the SOR-UDCA conjugate prodrug]

[0213] Twenty-four Wistar rats (half male and half female) were randomly divided into four groups of six each according to their weight and sex using a random number table. The rats were fasted for 12 hours.

[0214] For the administration of SOR via gavage, one group received SOR at a dose of 50.0 mg / kg. -1 The other three groups received equal doses of SOR-UDCA prodrug (enterically coated) according to molar ratios. Blood samples of 300 μL were collected from the orbital rim at 0.25, 0.5, 1.0, 2.0, 3.0, 4.0, 6.0, 8.0, 12, 24, and 48 hours after administration. The blood was then pumped at 13000 rpm. -1 Centrifuge for 10 minutes, collect the upper plasma layer and store it in a -80℃ freezer.

[0215] Accurately transfer 100 μL of plasma sample into a centrifuge tube, add 300 μL of methanol, which contains 10 μL of 10 μg / mL methanol. -1 Regorafenib (REG) internal standard solution, shake for 2 min, 13000 r·min -1 Centrifuge for 10 min, take 100 μL of the supernatant, filter through a 0.22 μm microporous membrane, and determine the SOR content by LC-MS.

[0216] SOR-UDCA's in vivo drug metabolism, such as Figure 21 As shown in Table 1, the relevant pharmacokinetic parameters are as follows.

[0217] Table 1. Pharmacokinetic parameters of serum SOR in different treatment groups

[0218]

[0219]

[0220] Note: Compared with SOR, *: P<0.05, **: P<0.01.

[0221] The results showed that in the SOR group, the C of SOR was... max It was (1.16±0.27) μg·mL -1 The C of SOR detected in the three SOR-UDCA prodrugs max The concentrations were SOR-10C-UDCA (5.17 ± 1.31) μg·mL, respectively. -1 >SOR-4C-UDCA(3.31±1.46)μg·mL -1 >SOR-2C-UDCA(2.33±0.79)μg·mL -1 The level was significantly higher in the group than in the SOR group, with a statistically significant difference (P < 0.05).

[0222] Meanwhile, in the SOR group, the AUC of SOR is... 0-∞ It was (26.72±13.11) μg·mL -1 •h, while the AUC of SOR detected in the three SOR-UDCA prodrugs 0-∞ The concentrations were SOR-10C-UDCA (269.90±77.84) μg·mL, respectively. -1 ·h>SOR-4C-UDCA(134.15±45.16)μg·mL -1 ·h>SOR-2C-UDCA(120.13±34.79)μg·mL -1The levels of SOR and H were significantly higher in the SOR group than in the SOR group, with statistically significant differences (P < 0.01). Among them, the SOR-10C-UDCA group had the highest detected SOR content, which increased by 10.10 times.

[0223] The results showed that the three SOR-UDCA prodrugs could increase the drug's blood concentration and bioavailability. When SOR-UDCA was administered orally, the drug was rapidly absorbed into the bloodstream via the small intestine and degraded into the original form of SOR in rats to continue its effect. The bioavailability AUC was also observed. 0-48h or AUC 0-∞ All were significantly higher than those in the SOR group, with statistically significant differences (P < 0.01).

[0224] The above tests show that the present invention successfully prepared a sorafenib-cholic acid conjugate prodrug with high yield and easier purification. The synthesized prodrug effectively increased the in vitro dissolution and in vivo bioavailability of the drug, providing a scientific method for the solubilization of sorafenib. At the same time, it also laid the data foundation and scientific method for the development of other poorly soluble substances into prodrugs.

[0225] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib via stepwise conjugation, characterized in that, Includes the following steps: tert-butyl-(iodooxy)dimethylsilane is linked to the front end of sorafenib to obtain the first compound; wherein the structural formula of the first compound is shown in Formula I; The first compound is linked to the back end of sorafenib to obtain the second compound; wherein the structural formula of the second compound is shown in Formula II; The second compound undergoes de-TBSO to form an alcohol, yielding the third compound; the structural formula of the third-generation compound is shown in Formula III. The third compound is linked with a bile acid compound to obtain a sorafenib-chole acid conjugate prodrug; In formulas I to III, n = 2 to 10; TBSO: tert-butyldimethylsilyl.

2. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 1, characterized in that, The cholic acid compound is ursodeoxycholic acid, and the structural formula of the sorafenib-cholic acid conjugate prodrug is shown in Formula IV. In the formula, n = 2 to 10.

3. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 1, characterized in that, The tert-butyl-(iodooxy)dimethylsilane is linked to the sorafenib front end to obtain the first compound, which specifically includes the following steps: At room temperature, 4-(4-aminophenoxy)-N-methyl-2-pyridinecarboxamide was dissolved in anhydrous acetonitrile, and tert-butyl-(iodooxy)dimethylsilane, potassium carbonate and sodium iodide were added in sequence. After the addition was completed, the mixture was transferred to 90°C and the reaction was stirred. After the reaction was completed, the reaction solution was cooled to room temperature and then subjected to reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product to obtain the first compound.

4. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 2, characterized in that, The equivalent ratio of 4-(4-aminophenoxy)-N-methyl-2-pyridinecarboxamide, tert-butyl-(iodooxy)dimethylsilane, potassium carbonate, and sodium iodide is 1:3:3:0.3 to 1:5:5:

1.

5. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 1, characterized in that, The first compound is linked to the back end of sorafenib to obtain the second compound, specifically including the following steps: At room temperature, the first compound was dissolved in anhydrous dichloromethane, and 4-chloro-3-trifluoromethyl isocyanate and triethylamine were added sequentially. After the addition was complete, the reaction was continued with stirring at room temperature. After the reaction was completed, the second compound was obtained through reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product.

6. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 4, characterized in that, The equivalent ratio of the first compound, phenyl 4-chloro-3-trifluoromethyl isocyanate, and triethylamine is 1:4:5 to 1:5:

8.

7. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 1, characterized in that, The second compound is de-oxidized from TBSO to an alcohol to obtain the third compound, specifically including the following steps: At room temperature, the second compound was dissolved in anhydrous dichloromethane, tetrabutylammonium fluoride was added, and the reaction was continued with stirring at room temperature after the addition was completed. After the reaction was completed, the third compound was obtained through reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product.

8. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 6, characterized in that, The equivalent ratio of the second compound to tetrabutylammonium fluoride is 1:2 to 1:

5.

9. The method for preparing sorafenib-cholic acid conjugate prodrugs based on modular assembly of sorafenib according to claim 1, characterized in that, The third compound is linked with a cholic acid compound to obtain a lafenib-cholic acid conjugate prodrug, which specifically includes the following steps: At room temperature, the third compound, the bile acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine were simultaneously dissolved in anhydrous DMF, and the reaction was continued with stirring at room temperature; wherein the equivalent ratio of the third compound, the bile acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine was 1:2:4:1 to 1:5:5:3; After the reaction was completed, the sorafenib-cholic acid conjugate prodrug was obtained through reaction quenching, extraction, organic phase washing, drying, filtration, and vacuum distillation of the filtrate and purification of the crude product.

10. A sorafenib-cholic acid conjugate prodrug prepared by the method according to any one of claims 1-9.

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