Preparation method of deoxycholic acid intermediate and deoxycholic acid or related salts thereof

Abstract

The invention provides a preparation method of a deoxycholic acid intermediate and deoxycholic acid or related salts thereof, which comprises the following steps: S1, carrying out hydrogenation reaction on 9-hydroxyandrostenedione to generate a compound 1; s2, carrying out Wittig reaction on the compound 1 to generate a compound 2; s3, reacting the compound 2 with methyl acrylate in the presence of Lewis acid, and hydrolyzing in the presence of hydrochloric acid to generate a compound 3; s4, eliminating hydroxyl of the compound 3 to generate a compound 4; s5, carrying out hydrogenation reduction on the compound 4 to generate a compound 5; s6, reacting the compound 5 with chromium trioxide to generate a compound 6; s7, carrying out hydrogenation reduction on the compound 6 to generate a compound 7; s8, performing chiral reduction on the compound 7 to generate a compound 8; and S9, hydrolyzing the compound 8 to generate deoxycholic acid. Compared with the currently reported route, the preparation method has the advantages that 3-6 steps of reaction are reduced, the total yield is 31.5% in terms of 9-hydroxyandrostenedione, and the key hydrogenation step is high in reaction speed, few in by-product, high in yield and convenient to operate. And the reaction operation is simple, and industrial production is easy.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical chemistry, and specifically relates to a method for preparing a deoxycholic acid intermediate and deoxycholic acid or a related salt thereof. Background Art

[0002] Bile acid is the most abundant and largest component in animal bile, accounting for more than 50% of the total amount of animal bile. People have been studying bile acid and bile acid chemistry for more than half a century. Bile acid is a complex organic compound with cyclopentane and polyhydrophenanthrene as the basic parent nucleus, a rigid steroid nucleus and aliphatic side chains, and an aliphatic angular methyl structure linked to the 10th and 13th positions of the fused ring, of which 3, 6, 7, and 12 can all be replaced by active oxygen-containing functional groups. Bile acids are divided into different levels of bile acids according to the number and position of the functional group substitutions.

[0003] According to the structure, bile acids can be divided into free bile acids and conjugated bile acids. Among them, cholic acid, chenodeoxycholic acid, and deoxycholic acid are called free bile acids. The products of free bile acids combined with glycine or taurine, such as glycocholic acid, taurochenodeoxycholic acid, etc., are called conjugated bile acids. Moreover, free and conjugated bile acids mainly exist in the form of stable salts, so they can also be called bile salts. Conjugated bile acids are easily soluble in dry water and have a low pH value in aqueous solution, which makes bile salts exist in a more stable form and are less likely to dissociate and precipitate solids under acidic conditions or in the presence of metal ions.

[0004] From the source, bile acids can be divided into primary bile acids, secondary bile acids and tertiary bile acids. Primary bile acids are produced from cholesterol in the liver, represented by cholic acid and chenodeoxycholic acid. After primary bile acids enter the intestine, they undergo deoxygenation reactions under the action of intestinal flora to generate secondary bile acids, mainly deoxycholic acid and ketolithocholic acid. After secondary bile acids participate in the body's circulation and are reused, the final product of metabolism in the intestine is called tertiary bile acid, which includes ursodeoxycholic acid and sulfolithocholic acid.

[0005] Deoxycholic acid (DCA) is also called deoxycholate and cholanic acid. Its chemical name is 3α, 12α-dihydroxy-5β-cholanic acid, and its structure is as follows:

[0006]

[0007] Deoxycholic acid is an injectable cytolytic drug that can destroy cell membranes and cause cell lysis when injected into body tissues. It was first developed by Kaisera Biopharmaceuticals and approved for marketing by the U.S. FDA on April 29, 2015 under the trade name Belkyra. It became the first FDA-approved lipolysis injection for the treatment of chin fat accumulation. It can be used to improve moderate to severe contour protrusion or excessive facial fullness of submandibular fat-related fat in adults, but it is not currently recommended for use in any area other than submandibular fat cells.

[0008] There are currently two main strategies for the synthesis of deoxycholic acid:

[0009] 1. A semi-synthetic strategy using cholic acid as the starting material, cholic acid undergoes sarret oxidation to selectively oxidize the 7-hydroxyl group to a carbonyl group, and then the 17-substituent is removed by Huang Minglong reduction to obtain the target product, deoxycholic acid. This synthetic method has fewer reaction steps and a simple process route.

[0010] However, this synthesis method obviously has the following problems: first, the currently commercialized bile acid is extracted from animal liver. Although the cost is low, it may contain animal-derived viruses or other harmful factors, and may cause high safety risks such as allergies. Secondly, the selectivity of the oxidation reaction in the synthesis process of this synthesis method is poor, and the intermediate needs to be purified by column chromatography. In addition, the Huang Minglong reduction method used has a high reaction temperature and will quickly release gas, which is not conducive to industrial production safety.

[0011] 2. Using the products obtained by fermentation of plant sterols, such as 9-hydroxyandrostenedione, cortisone or hydrocortisone, as starting materials, deoxycholic acid is prepared through a semi-synthetic strategy. This method fundamentally solves the biosafety issues of synthetic raw materials and deoxycholic acid APIs.

[0012] At present, the synthesis route of deoxycholic acid using hydrocortisone as the starting material requires 17 steps of reaction, and deoxycholic acid is synthesized with a total yield of 4.7%. Compared with the synthesis route of deoxycholic acid using 9-hydroxyandrostenedione as the starting material, the number of synthesis steps is longer, and multiple steps of hydrogenation, oxidation, and reduction reactions are required. In addition, one of the reduction steps requires the control of low temperature of -78°C, which is difficult to operate in industrial production, and the cost of synthesis is high. However, 9-hydroxyandrostenedione is a chemical raw material that has been commercialized on a large scale, has a wide range of uses in many fields, and has a stable supply from manufacturers. Therefore, most of the current deoxycholic acid synthesis routes use 9-hydroxyandrostenedione as the starting material.

[0013]

[0014] Kaisela Biopharmaceuticals reported in WO 2008157635 a method for synthesizing deoxycholic acid using 9-hydroxyandrostenedione as a starting material:

[0015]

[0016] Nanjing Norit Pharmaceutical Co., Ltd. reported a new method for synthesizing deoxycholic acid in CN106146593A. After 12 steps of reaction, deoxycholic acid was synthesized with a total yield of 22%. The method made the following improvements on the basis of WO 2008157635: (1) the carbonyl group at position 17 was protected by ketalization, and when the chiral hydroxyl group at position 3 was constructed, the competitive reaction of the carbonyl group at position 17 being reduced to hydroxyl group was avoided, and the low temperature reaction was also avoided; (2) the asymmetric hydrogenation at position 5 was adjusted to be carried out after the carbonyl group at position 17 was protected by ketalization, avoiding the formation of byproducts of the hydrogenation of the carbonyl group at position 17.

[0017]

[0018] However, the above two methods of synthesizing deoxycholic acid using 9-hydroxyandrostenedione as the starting material inevitably have the disadvantages of long route, low yield, long production cycle and complicated operation. Especially when the carbonyl conjugated double bond at position 12 is reduced, it is inevitable to use dry palladium carbon, which is very easy to ignite, and the reaction is slow to proceed. There are also a large number of by-products of excessive reduction of carbonyl groups, which need to be oxidized. In the experiment, hydrogenation and oxidation reactions need to be repeated 5-7 times, and the purity of the product is low, and the yield is not high. In production, only this step of reaction will consume a large amount of dry palladium carbon catalyst, which is complicated to operate, has a high risk factor, and the production cycle is several times that of the same type of reaction, which greatly increases the production cost.

[0019] Therefore, it is necessary to develop a method for preparing deoxycholic acid intermediates and deoxycholic acid or its related salts with a short route, high yield, simple operation and easy industrial production for the synthesis of deoxycholic acid. Summary of the invention

[0020] In view of the problems that the prior art methods for preparing deoxycholic acid intermediates and deoxycholic acid or its related salts have long routes, low yields, long production cycles, complicated operations, and are not conducive to industrial production, the present invention provides a method for preparing deoxycholic acid intermediates and deoxycholic acid or its related salts. The method reduces 3-6 reaction steps compared with the currently reported routes, has a fast reaction speed for the key hydrogenation step, has few by-products, a high yield, and is simple in reaction operation and is easy for industrial production.

[0021] To achieve the above object, the technical solution adopted by the present invention is:

[0022] A method for preparing a deoxycholic acid intermediate and deoxycholic acid or its related salts comprises the following steps:

[0023] S1. 9-hydroxyandrostenedione is subjected to hydrogenation reaction to generate compound 1. The specific reaction formula is as follows:

[0024]

[0025] S2. Compound 1 undergoes Wittig reaction to generate intermediate compound 2. The specific reaction formula is as follows:

[0026]

[0027] S3. In the presence of Lewis acid, compound 2 reacts with methyl acrylate, and then hydrolyzes in the presence of hydrochloric acid to generate compound 3. The specific reaction formula is as follows:

[0028]

[0029] S4. Compound 3 eliminates the hydroxyl group to generate compound 4. The specific reaction formula is as follows:

[0030]

[0031] S5. Compound 4 is hydrogenated and reduced to generate compound 5. The specific reaction formula is as follows:

[0032]

[0033] S6. Compound 5 reacts with chromium trioxide to generate compound 6. The specific reaction formula is as follows:

[0034]

[0035] S7. Compound 6 is hydrogenated and reduced to generate compound 7. The specific reaction formula is as follows:

[0036]

[0037] S8. Compound 7 is chiral reduced to generate compound 8. The specific reaction formula is as follows:

[0038]

[0039] S9. Compound 8 is hydrolyzed to generate deoxycholic acid. The specific reaction formula is as follows:

[0040]

[0041] Furthermore, the hydrogenation reaction in S1 is carried out in the presence of a catalyst, and the catalyst is Pd / C, Pd(OH) 2 / C、PtO 2 / C; S1 The reaction pressure of the hydrogenation reaction is 1.0-1.5 MPa.

[0042] Furthermore, the catalyst in S1 is Pd / C; and the reaction pressure is 1.0-1.2 MPa.

[0043] Further, the Lewis acid in S3 is AlCl 3 、EtAlCl 2 、TiCl 4 One or more of; S3 the reaction is carried out in an organic solvent, the organic solvent is one or more of dichloromethane, chloroform, tetrahydrofuran.

[0044] Furthermore, the Lewis acid in S3 is EtAlCl 2 ; The organic solvent is dichloromethane.

[0045] Further, the elimination reagent used to eliminate the hydroxyl group in S4 is concentrated sulfuric acid, concentrated hydrochloric acid, trifluoroacetic anhydride, TiCl 4 , acetic anhydride; S4 the reaction is carried out in an organic solvent, the organic solvent is one or more of dichloromethane, chloroform, tetrahydrofuran.

[0046] Furthermore, the elimination reagent in S4 is concentrated sulfuric acid, and the organic solvent is dichloromethane.

[0047] Furthermore, the hydrogenation reduction in S5 is carried out in the presence of a catalyst, wherein the catalyst is Pd / C, Pd(OH) 2 / C、PtO 2 / C; the hydrogenation reduction reaction pressure in S5 is 0.2-0.4 MPa; the reaction in S5 is carried out in an organic solvent, and the organic solvent is one or more of ethyl acetate, tetrahydrofuran, methanol and ethanol.

[0048] Furthermore, the catalyst in S5 is Pd / C, and the organic solvent is tetrahydrofuran.

[0049] Furthermore, the reaction in S6 is carried out in a solvent, and the solvent is one or more of acetic acid, NMP, dioxane, and tetrahydrofuran.

[0050] Furthermore, the solvent in S6 is acetic acid.

[0051] Further, the hydrogenation reduction in S7 is carried out in the presence of a catalyst, and the catalyst is Pd / C, Pd / C (dry), Pd(OH) 2 / C、PtO 2 / C, Raney nickel or more; S7 said hydrogenation reduction reaction pressure is 1.5-3.0MPa; said reaction temperature is 20-80°C.

[0052] Furthermore, the catalyst in S7 is Pd / C (dry), the reaction pressure is 2.0-2.5 MPa, and the reaction temperature is 55-65°C.

[0053] Further, the chiral reducing agent used for the chiral reduction in S8 is LiAl(Ot-Bu) 3 H, sodium triacetoxyborohydride, diisopinocampheyl chloroborane or more; the reaction temperature is -20 to 30°C.

[0054] Furthermore, the chiral reducing agent in S8 is LiAl(Ot-Bu) 3 H (lithium tri-tert-butoxyaluminum hydride tetrahydrofuran), the reaction temperature is -10 to 0°C.

[0055] Furthermore, the reaction in S9 is carried out under the conditions of a base and an organic reagent, wherein the base is one or more of sodium hydroxide, potassium hydroxide, and lithium hydroxide; and the organic reagent is one or more of dioxane, tetrahydrofuran, methanol, and ethanol.

[0056] Furthermore, the base in S9 is sodium hydroxide, and the organic reagent is tetrahydrofuran.

[0057] Another object of the present invention is to provide a deoxycholic acid intermediate.

[0058] A deoxycholic acid intermediate having a structure as shown in any one of compounds 1-8, prepared by any of the preparation methods described above.

[0059] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0060] The invention provides a simple and effective method for preparing a deoxycholic acid intermediate and deoxycholic acid or its related salts. The method uses 9-hydroxyandrostenedione as a starting material, and generates deoxycholic acid or its related salts through 9 steps of reactions such as hydrogenation reaction and Wittig reaction. Compared with the currently reported route, the method reduces 3-6 steps of reaction, and has fast reaction speed for the key hydrogenation step, few by-products, high yield, and is easy to operate. The total yield is 31.5% based on 9-hydroxyandrostenedione, which is significantly higher than the current reaction route. The reaction operation is simple and easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0062] Figure 1 The invention discloses a synthetic route for the preparation of a deoxycholic acid intermediate and deoxycholic acid or its related salts.

[0063] Figure 2 The figure is the HNMR spectrum of deoxycholic acid obtained by the method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts of the present invention.

[0064] Figure 3 The HPLC detection spectrum of deoxycholic acid obtained by the preparation method of the deoxycholic acid intermediate and deoxycholic acid or its related salts of the present invention. DETAILED DESCRIPTION

[0065] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention is further described by the following examples. Obviously, the following examples are only part of the embodiments of the present invention, rather than all the embodiments; it should be understood that the embodiments of the present invention are only used to illustrate the technical effects of the present invention, rather than to limit the scope of protection of the present invention.

[0066] The raw materials in the examples are all commercially available with purity meeting the requirements (>99.5%), reagents, solvents, etc. are all of chromatographic grade, and intermediate samples are homemade products and purchased from the market; unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0067] The present invention will be specifically described below by examples, which are not intended to limit the present invention. It will be appreciated by those skilled in the art that these examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually performed under conventional conditions or under conditions recommended by the manufacturer. The following examples are primarily intended to better understand the analytical method of the present invention and are not intended to be exhaustive of all operating methods.

[0068] A method for preparing a deoxycholic acid intermediate and deoxycholic acid or its related salts, comprising the following steps: Example 1: Preparation of deoxycholic acid intermediate 1

[0069] Add 10 L of methanol to the reactor, add 1 kg of 9-hydroxyandrostenedione under continuous stirring, and then add 100 g of Pd / C. Stir at room temperature, replace hydrogen, maintain the pressure at 1.0-1.2 MPa, and react at 25-35°C for 24 hours.

[0070] The reaction solution was filtered, the filter cake was rinsed with methanol, and the filtrate was concentrated to dryness to obtain a light yellow solid. The solid was then heated with 5 L of isopropanol to dissolve, 1 L of water was added dropwise, and the temperature was lowered to 0-10°C after keeping warm for 1 hour, and filtered. The filter cake was rinsed with an ice-cold isopropanol: water = 5:1 mixed solution to obtain a white solid, and dried at 45°C for 16 hours to obtain 975 g of a white to off-white solid, with a yield of 92.6%.

[0071] Example 2: Preparation of deoxycholic acid intermediate 2

[0072] Tetrahydrofuran was added to a three-necked flask, and 1670 g of triphenylethylphosphine bromide was added under stirring. The mixture was evacuated and replaced with nitrogen. The temperature was lowered to -10°C to -20°C under nitrogen protection. 504 g of potassium tert-butoxide was added. After the addition was completed, the temperature was maintained at -10°C to -20°C for 1 h. 954 g of compound 1 was added in batches. After the addition was completed, the temperature was raised to 20-30°C for 8 h. No raw material was detected by thin layer chromatography (TLC).

[0073] Slowly add 10 L of purified water to the reaction solution, add 5 L of ether after the addition of purified water is completed, stir for 30 minutes, let stand to separate the layers, extract the aqueous phase twice with 5 L of ether, combine the organic phases, wash the organic phase once with saturated sodium chloride, distill the organic phase under reduced pressure until no liquid flows out, add 2 L of isopropanol, and continue distillation under reduced pressure to obtain a brown solid-liquid mixture.

[0074] Add 5 L of isopropanol to the solid-liquid mixture and heat to 50-60 ° C to dissolve, cool to -10-0 ° C, crystallize for 1.0 h, filter, and wash the filter cake with 0.5 L of -10-0 ° C isopropanol solution to obtain a white solid. Dry at 45 ° C for 16 h to obtain 865 g of a white solid with a yield of 87.4%.

[0075] Example 3: Preparation of deoxycholic acid intermediate 3

[0076] Add 8.5 L of dichloromethane to a three-necked flask, add 850 g of compound 2 under stirring, stir and dissolve at room temperature, evacuate, replace nitrogen, cool to -10-0°C under nitrogen protection, add 317 g of methyl acrylate dropwise, after the addition is completed, keep -10-0°C to react for 1 h, add 2.6 L of dichloroethylaluminum n-hexane solution (25% wt), after the addition is completed, heat to 25-35°C and react for 24 h.

[0077] The reaction solution was slowly added dropwise to 8.5 L of ice water. After the addition was completed, the temperature was raised to 20-30°C, stirred for 30 minutes, and allowed to stand for stratification. The aqueous phase was extracted twice with dichloromethane, the organic phases were combined, washed with water and saturated sodium chloride, and the organic phase was distilled under reduced pressure until no liquid flowed out. 4.25 L of isopropanol was added, heated to dissolve, 0.85 L of purified water was added dropwise, solid precipitated, and the temperature was lowered to 0-10°C. Crystallization continued for 3 hours, and suction was filtered. The filter cake was rinsed with 0.85 L of a mixed solution of ice isopropanol: water = 5:1 to obtain a white solid. The filter cake was dried at 45°C for 16 hours to obtain 886 g of a white to off-white solid with a yield of 85.6%.

[0078] Example 4: Preparation of deoxycholic acid intermediate 4

[0079] Add 8.8 L of dichloromethane to a three-necked flask, add 880 g of compound 3 under stirring, stir at room temperature until completely dissolved, slowly add 4.4 g of concentrated sulfuric acid dropwise, raise the temperature to 38-40°C, maintain slight reflux, and react for 5 h.

[0080] The reaction system was cooled to 0-10°C, 4.4 L of purified water was added, stirring was maintained for 30 minutes, and the mixture was allowed to stand for separation. The aqueous phase was back-extracted twice with 1 L of dichloromethane, the combined organic phases were washed once with purified water and saturated sodium chloride, respectively, the organic phase was dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain a light yellow solid. 2.5 L of isopropanol was added and slurried for 3 hours, and the solid was filtered. The filter cake was washed with isopropanol to obtain an off-white solid, which was dried at 45°C for 10 hours to obtain 788 g of an off-white solid with a yield of 93.8%.

[0081] Example 5: Preparation of deoxycholic acid intermediate 5

[0082] Add 4 L of tetrahydrofuran to the hydrogenation reaction kettle, add 768 g of compound 4 under stirring, stir until the solid is dissolved, add 76.8 g of 10% Pd / C, replace the hydrogen, maintain the pressure at 0.2-0.4 MPa, and react at 20-30°C for 16 h.

[0083] The reaction solution was filtered and washed with tetrahydrofuran. The filtrate was distilled under reduced pressure until no liquid flowed out to obtain a colorless oil. 1.5 L of acetonitrile was added to the oil and distilled under reduced pressure until no liquid flowed out. 4 L of acetonitrile was added to the oil and heated until all dissolved. The temperature was lowered to -10°C to 0°C, and a large amount of solid precipitated. The temperature was maintained to continue crystallization for 4 hours. The filter cake was filtered and rinsed with acetonitrile (-10°C to 0°C). The wet product was placed at 45°C for 16 hours to obtain 715 g of a white solid product with a yield of 92.6%.

[0084] Example 6: Preparation of deoxycholic acid intermediate 6

[0085] 700 g of compound 5 was dissolved in 7 L of acetic acid solution, 3627 g of solid chromium trioxide was added, and the mixture was heated to 60° C. and reacted for 16 h.

[0086] The reaction solution was cooled to room temperature, 35 L of purified water was added dropwise, stirred for 2 h, and filtered to obtain a light green solid. The solid was heated and dissolved with 3.5 L of methanol, cooled to -10 to 0 ° C, stirred and crystallized for 2 to 4 h, and filtered to obtain a white solid, which was dried at 45 ° C for 16 h to obtain 593 g of a white solid with a yield of 81.7%.

[0087] Example 7: Preparation of deoxycholic acid intermediate 7

[0088] Add 5.6L of methanol to the reactor, add 560g of compound 6 under stirring, stir until completely dissolved, add 84g of 10% Pd / C (dry), replace with nitrogen and then replace with hydrogen 3 times, pressurize the hydrogen to 2.0-2.5MPa, heat to 55-65℃ and react for 16h. Cool to 20-30℃, filter, rinse, concentrate the filtrate to about 1.7L, slowly add 1.1L of pure water, cool to 0-10℃, stir for 2h, filter, rinse, rinse the filter cake with a 1:1 mixed solution of methanol: water, and dry at 45℃ for 16h to obtain 522g of white solid with a yield of 92.8%.

[0089] Example 8: Preparation of deoxycholic acid intermediate 8 (crude product)

[0090] Add 5 L of anhydrous tetrahydrofuran to a three-necked flask, add 500 g of compound 7 under stirring, cool to -10 to 0 °C, slowly add 3.7 L of lithium tri-tert-butoxyaluminum hydride tetrahydrofuran solution (1 mol / L) dropwise, control the internal temperature not higher than 0 °C, and after the addition is complete, keep the reaction at -10 to 0 °C for 16 h.

[0091] Add 10 L of 2 mol / L dilute hydrochloric acid to the reaction solution at low temperature, control the internal temperature not higher than 20°C, add 10 L of ethyl acetate, stir, separate the layers, extract the aqueous phase once with 1 L of ethyl acetate, combine the organic phases, wash once with purified water and saturated brine respectively, distill the organic phase under reduced pressure to obtain a colorless oil, add 400 mL of methanol, continue distillation under reduced pressure to obtain a colorless oil, and use the crude product for the next step reaction without purification.

[0092] Example 9: Preparation of target deoxycholic acid

[0093] Transfer the crude oil from the previous step into a flask, add 2.5 L of a 1:1 mixed solution of methanol and tetrahydrofuran, dissolve under stirring, slowly add 2.5 L of a 2 mol / L NaOH solution, raise the temperature to 40-50°C and react for 1-2 h.

[0094] Add 2.5L of purified water to the reaction solution, remove methanol and tetrahydrofuran by distillation under reduced pressure, add 2mol / L hydrochloric acid dropwise while stirring to adjust the pH to 1-2, a large amount of solid precipitates, keep stirring at 20-30°C for 4-6h, filter, wash the filter cake with 0.5mol / L dilute hydrochloric acid, and then wash with purified water until the filtrate is neutral to obtain a white solid, dry at 45°C for 16-24h, and obtain 450g of crude deoxycholic acid (comprehensive yield of crude product 92.4%)

[0095] Take a three-necked flask, add 1L of methanol, add crude deoxycholic acid under stirring, all solids are dissolved, slowly add 7.5L of dichloromethane, the reaction solution is clarified, heated to 40-45°C, distilled at atmospheric pressure, solids slowly precipitate, take the supernatant of the reaction solution, and detect it with gas chromatography (GC). Control the methanol content in the reaction solution at 3-4%, stop adding dichloromethane and distillation, maintain the internal temperature at 20-30°C, stir and crystallize for 4-6h, filter, wash with 150mL of dichloromethane to obtain a white solid, and dry it with air at 45°C for 8-16h to obtain 365g of a white solid product with a yield of 81.2%.

[0096] Take a three-necked flask, add the deoxycholic acid solid in batches to a 2 mol / L sodium hydroxide solution, until the solid is completely dissolved, add 73 g of activated carbon, heat to 40-50 ° C, stir for 1-2 h, filter, cool to 10-20 ° C, add 2 mol / L dilute hydrochloric acid dropwise, adjust the pH to 1-2, stir at 20-30 ° C for 2-4 h, filter, rinse with purified water until the filtrate is neutral, and obtain a white solid. Dry at 45 ° C with air blast for 16-24 h to obtain 336 g of a white solid with a yield of 92.1%.

[0097] 1 H NMR (400 MHz, DMSO-d 6 )δ11.92(s,1H),4.45(d,J=4.2Hz,1H),4.20(d,J=4.0Hz,1H),3.79(q,J=3 .2Hz,1H),3.32(s,1H),2.22(ddd,J=15.1,9.6,5.2Hz,1H),2.09(ddd,J=1 5.6,9.1,6.8Hz,1H),1.85-1.43(m,10H),1.40-1.13(m,11H),1.02(ddd,J =25.3,12.9,4.5Hz,2H),0.91(d,J=6.4Hz,3H),0.84(s,4H),0.59(s,3H).

[0098] LCMS: 415.3 [M+Na] +

[0099] mp=172.1℃-173.6℃

[0100] HPLC (CAD) = 99.85%

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a deoxycholic acid intermediate and deoxycholic acid or its related salts, characterized in that: The following steps are involved: S1. 9-hydroxyandrostenedione is subjected to hydrogenation reaction to generate compound 1. The specific reaction formula is as follows: S2. Compound 1 undergoes a Wittig reaction to generate compound 2. The specific reaction formula is as follows: S3. In the presence of Lewis acid, compound 2 reacts with methyl acrylate, and then hydrolyzes in the presence of hydrochloric acid to generate compound 3. The specific reaction formula is as follows: S4. Compound 3 eliminates the hydroxyl group to generate compound 4. The specific reaction formula is as follows: S5. Compound 4 is hydrogenated and reduced to generate compound 5. The specific reaction formula is as follows: S6. Compound 5 reacts with chromium trioxide to generate compound 6. The specific reaction formula is as follows: S7. Compound 6 is hydrogenated and reduced to generate compound 7. The specific reaction formula is as follows: S8. Compound 7 is chiral reduced to generate compound 8. The specific reaction formula is as follows: S9. Compound 8 is hydrolyzed to generate deoxycholic acid. The specific reaction formula is as follows:

2. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: The hydrogenation reaction in S1 is carried out in the presence of a catalyst, and the catalyst is one or more of Pd / C, Pd(OH)2 / C, and PtO2 / C; the reaction pressure of the hydrogenation reaction in S1 is 1.0 to 1.5 MPa.

3. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: The Lewis acid in S3 is one or more of AlCl3, EtAlCl2, and TiCl4; the reaction in S3 is carried out in an organic solvent, and the organic solvent is one or more of dichloromethane, chloroform, and tetrahydrofuran.

4. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: The elimination reagent used to eliminate the hydroxyl group in S4 is one or more of concentrated sulfuric acid, concentrated hydrochloric acid, trifluoroacetic anhydride, TiCl4, and acetic anhydride; the reaction in S4 is carried out in an organic solvent, and the organic solvent is one or more of dichloromethane, chloroform, and tetrahydrofuran.

5. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: The hydrogenation reduction in S5 is carried out in the presence of a catalyst, and the catalyst is one or more of Pd / C, Pd(OH)2 / C, and PtO2 / C; the hydrogenation reduction reaction pressure in S5 is 0.2 to 0.4 MPa; the reaction in S5 is carried out in an organic solvent, and the organic solvent is one or more of ethyl acetate, tetrahydrofuran, methanol, and ethanol.

6. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: S6: The reaction is carried out in a solvent, and the solvent is one or more of acetic acid, NMP, dioxane, and tetrahydrofuran.

7. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: The hydrogenation reduction in S7 is carried out in the presence of a catalyst, and the catalyst is one or more of Pd / C, Pd / C (dry), Pd(OH)2 / C, PtO2 / C, and Raney nickel; the hydrogenation reduction reaction pressure in S7 is 1.5 to 3.0 MPa; and the reaction temperature is 20 to 80°C.

8. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: S8: The chiral reducing agent used for the chiral reduction is one or more of LiAl(Ot-Bu)3H, sodium triacetoxyborohydride, and diisopinocampheyl chloroborane; the reaction temperature is -20 to 30°C.

9. A method for preparing the deoxycholic acid intermediate and deoxycholic acid or its related salts as claimed in claim 1, characterized in that: The reaction in S9 is carried out under the conditions of a base and an organic reagent, wherein the base is one or more of sodium hydroxide, potassium hydroxide, and lithium hydroxide; and the organic reagent is one or more of dioxane, tetrahydrofuran, methanol, and ethanol.

10. A deoxycholic acid intermediate, characterized in that: It has a structure as shown in any one of compounds 1-8 and is prepared by the preparation method described in any one of claims 1-9.

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