WO2023280313A1

WO2023280313A1 - Method for purifying ursodeoxycholic acid

Info

Publication number: WO2023280313A1
Application number: PCT/CN2022/104683
Authority: WO
Inventors: 仇文卫; 李晨晨; 顾向忠; 蒋澄宇; 吴殊岚; 林林
Original assignee: 华东师范大学; 江苏佳尔科药业集团股份有限公司
Priority date: 2021-07-09
Filing date: 2022-07-08
Publication date: 2023-01-12
Also published as: CN113480589B; CN113480589A

Abstract

Disclosed is a method for purifying ursodeoxycholic acid (UDCA), comprising the following steps: step A sets forth the preparation of 4-dimethylpyridine ammonium salt of UDCA; and step B sets forth the hydrolysis of the 4-dimethylpyridine ammonium salt of UDCA. In the present invention, operation is simple, solvents and reagents used are low in cost and readily available, the present invention is suitable for industrial production, and the purity of the obtained UDCA is high.

Description

A kind of purification method of ursodeoxycholic acid

technical field

The invention relates to the field of separation of pharmaceutical intermediates, in particular to a method for purifying ursodeoxycholic acid.

Background technique

Ursodeoxycholic acid (Ursodeoxycholic acid, UDCA) (as shown in formula 1), chemical name 3α, 7β-dihydroxy-5β-cholestane-24-acid (3α, 7β-dihydroxy-5β-cholan-24- oic acid), CAS No. 128-13-2, molecular formula C ₂₄ H ₄₀ O ₄ , molecular weight 392.56, white powder, odorless, bitter taste, melting point 203-204°C. Ursodeoxycholic acid is the main ingredient contained in the precious traditional Chinese medicine bear bile. It is the first-line treatment drug for primary biliary cirrhosis (PBC) approved by the US FDA. It can also effectively treat gallstone diseases and chronic liver diseases in clinical practice. , has broad market prospects. At present, there are mainly two methods for the preparation of ursodeoxycholic acid: animal bile extraction and artificial synthesis. However, the source of animal bile extraction is limited and it is difficult to meet clinical needs, so it mainly relies on artificial synthesis.

At present, because chenodeoxycholic acid is cheap and easy to obtain, chenodeoxycholic acid is mainly used as raw material in industry, through chemical oxidation and reduction reactions (Bioorganic & Medicinal Chemistry, 2016, 24:3986-3993. etc.) or enzymatic oxidation and reduction Reaction (Bioprocess and Biosystems Engineering, 2019, 42(9):1537-1545. etc.) to prepare ursodeoxycholic acid. In this reaction product, in addition to the product ursodeoxycholic acid, there are intermediates 7-ketolithocholic acid (7K-LCA, 3α-hydroxy-7-carbonyl-5β-cholic acid) and chenodeoxycholic acid ( Chenodeoxycholic acid, CDCA, 3α, 7α-dihydroxy-5β-cholan-24-acid) and other by-products, purification is more difficult.

At present, the industry mainly uses solvents such as ethyl acetate to wash and purify for many times, and selectively dissolve and remove chenodeoxycholic acid and other related impurities from the mixture containing ursodeoxycholic acid. In actual production, more than 30 times of ethyl acetate is required. Only esters can dissolve and remove impurities such as chenodeoxycholic acid, the solvent consumption is large, the cost is high, and the purification effect is not ideal. Chinese patent literature (CN106928306A) discloses that crude ursodeoxycholic acid is treated with triethylamine, and after three steps of refining, refined ursodeoxycholic acid is obtained, the product recovery rate is 82.8%-85.3%, the operation is relatively complicated, and the yield Not ideal either.

Contents of the invention

The purpose of the present invention is to address the above existing problems and deficiencies, and provide a purification method that is easy to operate, uses solvents and reagents that are cheap and easy to obtain, obtains ursodeoxycholic acid with high purity, and is suitable for industrial production.

In order to achieve the above object, the present invention provides a method for purifying ursodeoxycholic acid, which is characterized in that it comprises the following steps:

A. Preparation of 4-lutidine ammonium salt of ursodeoxycholic acid

Dissolve the crude ursodeoxycholic acid in the mixed solution of the first solvent and the second solvent, stir and heat up to 55-70°C, add 4-dimethylaminopyridine (DMAP), heat up and reflux for 1-4h, and slowly cool down, Stir at 0-5°C for 0.5-4h, filter with suction, wash the filter cake with the first solvent, and dry to obtain 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid.

B. Hydrolysis of 4-lutidinium salt of ursodeoxycholic acid

Suspend the 4-lutidine ammonium salt of ursodeoxycholic acid obtained in step A in water, add alkali, adjust the pH to 12.0-12.5, stir at 20-25°C for 1-4h; add acid dropwise Adjust the pH to 2.0-2.5, stir at 20-25°C for 1-4h; filter, collect the filter cake, wash with water, and dry to obtain pure ursodeoxycholic acid.

Described reaction process is as shown in route (I):

Route (I)

In step A,

The purity of the crude ursodeoxycholic acid is 70%-90%; preferably, 90%.

The first solvent is acetone.

The second solvent is selected from one or more of tetrahydrofuran, methanol, ethanol, etc.; preferably, the second solvent is methanol.

The volume (ml) of the first solvent added is 4-8 times the weight (grams) of the crude ursodeoxycholic acid; preferably, it is 6 times.

The volume (ml) of the second solvent added is 0.3-1 times the weight (grams) of the crude ursodeoxycholic acid; preferably, it is 0.5 times.

The added amount of the 4-dimethylaminopyridine is 0.31-0.47 times of the weight of the crude product of ursodeoxycholic acid; preferably, the weight of the 4-dimethylaminopyridine is 0.32 times of the crude product of ursodeoxycholic acid. times.

The volume (mL) of the first solvent for washing the filter cake is 1-3 times the weight (g) of the crude ursodeoxycholic acid; preferably, 1 time.

The temperature of the temperature-rising reflux reaction is 55-70°C; preferably, 65°C.

The time for the temperature-raising reflux reaction is preferably 2 hours.

Stir preferably for 1 h at 0-5 °C.

In step B,

The volume (ml) of water used for suspending the 4-dimethylaminopyridinium salt of ursodeoxycholic acid is 5-20 times the weight (grams) of the crude ursodeoxycholic acid; preferably, it is 15 times.

The alkali is one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, etc.; preferably, it is sodium hydroxide.

The acid is one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, etc.; preferably, it is hydrochloric acid.

The concentration of the base is 1-8 mol/L; preferably, 2 mol/L.

The volume fraction of the acid is 10%-90%; preferably, 10%.

The volume (ml) of water used for washing the filter cake is 1-5 times the weight (grams) of ursodeoxycholic acid; preferably, it is 2 times.

Preferably, base is added to adjust the pH to 12.0.

Preferably, acid is added to adjust the pH to 2.0.

In the present invention, after adding alkali or adding acid to adjust the pH, it is preferably stirred at 20-25° C. for 1 h.

The beneficial effects of the present invention include: the purification method of ursodeoxycholic acid of the present invention, the solvent used is easy to obtain, the operation is simple, only two purification steps are used, the purity of the refined ursodeoxycholic acid is greater than 99%, and the energy consumption is less. It is convenient for industrialized production.

detailed description

In conjunction with the following specific examples, the present invention will be further described in detail, and the process, conditions, reagents, experimental methods, etc. of implementing the present invention, except for the content specifically mentioned below, are general knowledge and common knowledge in the art, the present invention Contents are not particularly limited.

Embodiment one

Dissolve 10 g of crude ursodeoxycholic acid with 90% purity in a mixed solution of acetone (60 mL) and methanol (5 mL), stir and heat up to 60 ° C, add 4-dimethylaminopyridine (3.2 g), and The reaction solution was reacted for 2 hours, then the reaction liquid was cooled, stirred at 0-5° C. for 1 hour, suction filtered, the filter cake was washed with acetone (10 mL), and dried in vacuo to obtain 4-lutidine ammonium salt of ursodeoxycholic acid ( 11.6g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (150 mL), add 2 mol/L sodium hydroxide aqueous solution, adjust the pH to 12.0, stir at 20-25 °C for 1 h; add dropwise 10 % dilute hydrochloric acid to adjust the pH to 2.0, and stirred at 20-25°C for 1h; filtered, collected the filter cake and washed with water (200mL), and dried in vacuo to obtain 8.74g of ursodeoxycholic acid (liquid phase purity>99%), bear The purification yield of deoxycholic acid was 97.1%.

Embodiment two

Dissolve 10 g of crude ursodeoxycholic acid with 80% purity in a mixed solution of acetone (60 mL) and methanol (5 mL), stir and heat up to 60° C., add 4-dimethylaminopyridine (3.2 g), and The reaction mixture was reacted at low temperature for 1.5h, then the reaction solution was cooled, stirred at 0-5°C for 1h, filtered with suction, the filter cake was washed with acetone (10mL), and dried in vacuo to obtain 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid (10g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (150 mL), add 4 mol/L sodium hydroxide aqueous solution, adjust the pH to 12.0, stir at 20-25 °C for 1 h; add dropwise 10 % dilute hydrochloric acid to adjust the pH to 2.0, and stirred at 20-25°C for 1h; filtered, collected the filter cake and washed with water (200mL), and dried in vacuo to obtain 7.65g of ursodeoxycholic acid (liquid phase purity>99%), bear The purification yield of deoxycholic acid was 95.6%.

Embodiment Three

Dissolve 10 g of 85% pure ursodeoxycholic acid in a mixed solution of acetone (60 mL) and ethanol (5 mL), stir and heat up to 60 ° C, add 4-dimethylaminopyridine (3.2 g), and The reaction solution was reacted for 2 hours, then the reaction solution was cooled, stirred at 0-5°C for 2 hours, suction filtered, the filter cake was washed with acetone (10 mL), and dried in vacuo to obtain 4-lutidine ammonium salt of ursodeoxycholic acid ( 10.7g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (150 mL), add 2 mol/L sodium hydroxide aqueous solution, adjust the pH to 12.5, stir at 20-25 °C for 1 h; add dropwise 10 % dilute hydrochloric acid to adjust the pH to 2.5, and stirred at 20-25°C for 1h; filtered, collected the filter cake and washed with water (300mL), and dried in vacuo to obtain 8.07g of pure ursodeoxycholic acid (liquid phase purity>99%) , The purification yield of ursodeoxycholic acid was 95%.

Embodiment Four

Dissolve 10 g of crude ursodeoxycholic acid with 90% purity in a mixed solution of acetone (60 mL) and tetrahydrofuran (5 mL), stir and heat up to 60 ° C, add 4-dimethylaminopyridine (3.2 g), and The reaction solution was reacted for 2 hours, then the reaction solution was cooled, stirred at 0-5°C for 2 hours, filtered with suction, the filter cake was rinsed with acetone (10 mL), and dried in vacuo to obtain 4-dimethylpyridinium ammonium ursodeoxycholic acid Salt (11.4g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (100 mL), add 4 mol/L sodium hydroxide aqueous solution, adjust the pH to 12.5, stir at 20-25 °C for 2 h; add dropwise 30 % dilute hydrochloric acid to adjust the pH to 2.0, stir at 20-25°C for 2h; filter, collect the filter cake and wash with water (150mL), and vacuum-dry to obtain 8.5g of pure ursodeoxycholic acid (purity in liquid phase>99%) , the purification yield of ursodeoxycholic acid was 94.4%.

Embodiment five

Dissolve 10 g of crude ursodeoxycholic acid with 90% purity in a mixed solution of acetone (60 mL) and methanol (8 mL), stir and heat up to 70 ° C, add 4-dimethylaminopyridine (3.6 g), and The reaction solution was reacted for 3 h at lower temperature, then the reaction solution was cooled, stirred at 0-5° C. for 1 h, filtered with suction, the filter cake was washed with acetone (20 mL), and dried in vacuo to obtain 4-lutidine ammonium salt of ursodeoxycholic acid ( 11.3g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (200mL), add 2mol/L sodium hydroxide aqueous solution, adjust the pH to 12.0, stir at 20-25°C for 2h; add dropwise 10 % dilute hydrochloric acid to adjust the pH to 2.3, and stirred at 20-25°C for 2h; filtered, collected the filter cake and washed with water (400mL), and dried in vacuo to obtain 8.58g of ursodeoxycholic acid (liquid phase purity>99%), bear The purification yield of deoxycholic acid was 95.3%.

Embodiment six

10g of crude ursodeoxycholic acid with 90% purity was dissolved in a mixed solution of acetone (70mL) and ethanol (6mL), stirred and heated to 70°C, added 4-dimethylaminopyridine (3.2g), and heated at 60°C The reaction solution was reacted for 3 h at low temperature, then the reaction solution was cooled, stirred at 0-5° C. for 1 h, filtered with suction, the filter cake was washed with acetone (15 mL), and dried in vacuo to obtain 4-lutidine ammonium salt of ursodeoxycholic acid ( 11.2g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (200 mL), add 4 mol/L lithium hydroxide aqueous solution, adjust the pH to 12.0, stir at 20-25 °C for 2 h; add dropwise 10 % dilute sulfuric acid to adjust the pH to 2.5, and stirred at 20-25°C for 2h; filtered, collected the filter cake and washed with water (200mL), and dried in vacuo to obtain 8.53g of ursodeoxycholic acid (liquid phase purity>99%), bear The purification yield of deoxycholic acid was 94.8%.

Embodiment seven

10g of crude ursodeoxycholic acid with 88% purity was dissolved in a mixed solution of acetone (60mL) and ethanol (5mL), stirred and heated to 55°C, added 4-dimethylaminopyridine (4.0g), and heated at 65°C The reaction solution was reacted for 2 hours at low temperature, then the reaction solution was cooled, stirred at 0-5°C for 2 hours, filtered with suction, the filter cake was washed with acetone (20 mL), and dried in vacuo to obtain 4-lutidine ammonium salt of ursodeoxycholic acid ( 11.0 g).

Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (150 mL), add 4 mol/L sodium hydroxide aqueous solution, adjust the pH to 12.0, stir at 20-25 ° C for 2 h; dropwise add 50 % dilute hydrochloric acid to adjust the pH to 2.0, and stir at 20-25°C for 2h; filter, collect the filter cake and wash with water (100mL), and vacuum-dry to obtain 8.38g of pure ursodeoxycholic acid (liquid phase purity>99%) , the purification yield of ursodeoxycholic acid was 95.2%.

Comparative example one

The operation steps of the patent document CN 110669091A are as follows:

(1) dissolving the mixture containing ursodeoxycholic acid in tetrahydrofuran, adding diisopropylethylamine to react to obtain a solution containing ursodeoxycholic acid diisopropylethylammonium salt; (2) Cool the solution of ursodeoxycholic acid diisopropylethylammonium salt obtained in step (1) at 0-5° C. to crystallize and separate to obtain ursodeoxycholic acid diisopropylethylammonium salt; (3 ) Suspend ursodeoxycholic acid diisopropylethylammonium salt in ultrapure water, add sodium hydroxide aqueous solution, adjust the pH to 12.0-12.5; after dichloromethane extraction, put the water phase into the reaction flask , stirring and heating up, adding dilute hydrochloric acid dropwise to adjust the pH to 2.0-2.5; cooling the slurry, filtering, collecting the filter cake, washing with ultrapure water, and drying to obtain pure ursodeoxycholic acid.

In the process of purifying ursodeoxycholic acid by the method disclosed in the patent document CN 110669091A, the precipitation of ursodeoxycholic acid diisopropylethylammonium salt crystals was not observed, and the ursodeoxycholic acid product could not be purified. The specific operation steps are as follows:

Dissolve 10 g of crude ursodeoxycholic acid with a purity of 90% in tetrahydrofuran (100 mL), stir and heat up to 55° C., add diisopropylethylamine (3.3 g), and react at 65° C. for 1 h, and then dissolve the obtained The reaction liquid was cooled to 0-5° C., no crystals of ursodeoxycholic acid diisopropylethylammonium salt were observed, and no pure ursodeoxycholic acid was obtained. Therefore, the method disclosed in this patent document CN 110669091A is not feasible to purify ursodeoxycholic acid.

Comparative example two

The base 4-dimethylaminopyridine used in the method of the present invention is replaced by diisopropylethylamine used in the patent document CN 110669091A, other steps are the same as the examples of the present invention, and it is found that the purification of ursodeoxycholic acid product The yield is much lower than the examples of the present invention. The specific operation steps are as follows:

The crude product of ursodeoxycholic acid of 10g 90% purity is dissolved in the mixed solution of acetone (60mL) and methanol (5mL), is stirred and is warming up to 60 ℃, adds diisopropylethylamine (3.64g), and at 65 React at ℃ for 2 hours, then cool the reaction solution, and stir at 0-5℃ for 1 hour, no ursodeoxycholic acid diisopropylethylammonium salt crystals were observed, and finally the ursodeoxycholic acid product could not be purified . Therefore, although the diisopropylethylamine used in the patent document CN 110669091A is also a kind of organic base, it is not suitable for the purification method of the present invention, and the organic base 4-dimethylaminopyridine used in the present invention is obtained by this method. The inventor obtained it through multiple tests and screenings, and it is used for the purification of crude ursodeoxycholic acid, and the effect is excellent. Comparative example three

The diisopropylethylamine in the patent document CN 110669091A was replaced by the 4-dimethylaminopyridine mentioned in the present invention, and the other steps were the same as the patent document CN 110669091A, but the ursodeoxycholic acid product could not be purified. The specific operation steps are as follows:

Dissolve 10 g of crude ursodeoxycholic acid with 90% purity in tetrahydrofuran (100 mL), stir and heat up to 55 ° C, add DMAP (3.2 g), and react at 65 ° C for 1 h, then cool the reaction solution to 0-5 ℃, no 4-dimethylpyridinium ammonium salt crystals of ursodeoxycholic acid were observed, and finally the ursodeoxycholic acid product could not be purified.

Comparative example four

The operation steps of the patent document CN 106928306A are as follows:

(1) Dissolve the mixture containing ursodeoxycholic acid in a mixed solution of acetone and ethanol, stir and heat up, add triethylamine to react, and prepare a solution containing ursodeoxycholic acid triethylammonium salt, cool, filter Obtain ursodeoxycholic acid triethylammonium salt; (2) add ursodeoxycholic acid triethylammonium salt into acetone and water, heat up and dissolve, add glacial acetic acid to adjust pH to 4-5, add activated carbon for decolorization, filter out activated carbon, Atmospheric distillation recovers acetone, cools the reaction liquid, filters, and dries to obtain ursodeoxycholic acid; (3) recrystallizes and refines ursodeoxycholic acid obtained in step (2) with ethyl acetate, filters, and dries to obtain ursodeoxycholic acid The cholic acid, ursodeoxycholic acid, has a purification yield of 82.8%-85.3%.

The present invention repeats the method disclosed in the patent document CN 106928306A to purify ursodeoxycholic acid. As a result, it is found that the purification yield of ursodeoxycholic acid product is far lower than that of the examples of the present invention. The specific operation steps are as follows:

(1) Dissolve 10g of crude ursodeoxycholic acid with 80% purity in a mixed solution of acetone (60mL) and ethanol (5mL), stir and heat up to 46°C, maintain the temperature for 1.5h, add one volume of triethylamine (10 mL), heated to reflux for 1.5 h, cooled to 14 ° C, stirred for 4 h, filtered, washed the filter cake with acetone (10 mL), and dried to obtain triethylammonium salt of ursodeoxycholic acid (8.5 g). (2) The above-mentioned triethylammonium salt of ursodeoxycholic acid is suspended in water (150mL), add acetone (100mL) and water (30mL), stir and heat up to 46°C, maintain the temperature for 0.5h, and after it is completely dissolved, add dropwise Glacial acetic acid adjusted the pH value at 4.7, added 5% mass of activated carbon (0.5g) for decolorization for 2h, filtered the activated carbon, washed the activated carbon with a mixed solution of acetone (7mL) and water (3mL), and recovered the acetone by atmospheric distillation below 65°C to The residual liquid is about 70mL, stop the recovery, slowly cool down to 10-15°C, stir for 1h, filter, wash the filter cake with water (10mL), and dry to obtain the crude ursodeoxycholic acid; (3) the ursodeoxycholic acid obtained in step (2) Add 3 times the volume of ethyl acetate to cholic acid, heat up and reflux for 2 hours, slowly cool down to 0-5°C, stir for 4 hours, filter, and dry to obtain 6.6 g of ursodeoxycholic acid, with a purification yield of 82.5%. The deoxycholic acid purification yield is lower than the embodiment of the method of the present invention.

Comparative example five

The 4-dimethylaminopyridine used in the present invention is replaced by the triethylamine used in the patent document CN 106928306A, other steps are the same as the examples of the present invention, and it is found that the purification yield of the ursodeoxycholic acid product is far lower than that of the present invention the embodiment. The specific operation steps are as follows:

Dissolve 10 g of crude ursodeoxycholic acid with a purity of 90% in a mixed solution of acetone (60 mL) and ethanol (5 mL), stir and heat up to 60°C, add triethylamine (2.84g), and react at 65°C for 2h , and then the reaction solution was cooled, stirred at 0-5° C. for 1 h, filtered with suction, and the filter cake was washed with acetone (10 mL), dried in vacuo to obtain triethylammonium salt of ursodeoxycholic acid (9.5 g). Suspend the above triethylammonium salt of ursodeoxycholic acid in water (150mL), add 2mol/L aqueous sodium hydroxide solution, adjust the pH to 12.0, stir at 20-25°C for 1h; add 10% dilute Adjust the pH to 2.0 with hydrochloric acid, stir at 20-25°C for 1 h; filter, collect the filter cake, wash with water, and dry in vacuo to obtain 7.56 g of pure ursodeoxycholic acid, and the purification yield of ursodeoxycholic acid is 84%. The ursodeoxycholic acid purification yield of the method is lower than the embodiment of the method of the present invention.

Comparative example six

Replace the triethylamine in the patent document CN 106928306A with the 4-dimethylaminopyridine mentioned in the present invention, other steps are the same as the patent document CN106928306A, the purification efficiency of the ursodeoxycholic acid product is lower than the embodiment of the present invention. The specific operation steps are as follows:

(1) Dissolve 10g of crude ursodeoxycholic acid with 80% purity in a mixed solution of acetone (60mL) and ethanol (5mL), stir and heat up to 46°C, maintain the temperature for 1.5h, add DMAP (8.8mL), and heat up Reflux for 1.5 h, cool down to 14°C, stir for 4 h, filter, wash the filter cake with acetone (10 mL), and dry to obtain 4-lutidine ammonium salt of ursodeoxycholic acid (9.21 g). (2) Suspend the 4-lutidine ammonium salt of ursodeoxycholic acid in water (150mL), add acetone (100mL) and water (30mL), stir and raise the temperature to 46°C, maintain the temperature for 0.5h, and wait for complete dissolution Finally, add glacial acetic acid dropwise to adjust the pH value to 4.7, add 5% mass of activated carbon (0.5g) for decolorization for 2 hours, filter the activated carbon, wash the activated carbon with a mixed solution of acetone (7mL) and water (3mL), and store it under normal pressure below 65°C Distill and recover acetone until the residual liquid is about 70mL, stop the recovery, slowly cool down to 10-15°C, stir for 1h, filter, wash the filter cake with water (10mL), and dry to obtain the crude ursodeoxycholic acid; (3) Step (2) Add 3 times the volume of ethyl acetate to the obtained ursodeoxycholic acid, raise the temperature and reflux for 2 hours, slowly cool down to 0-5°C, stir for 4 hours, filter, and dry to obtain 6.87 g of ursodeoxycholic acid with a purification yield of 85.9%. The ursodeoxycholic acid purification yield of this method is lower than the embodiment of the method of the present invention.

Comparative example seven

The acetone in the patent of the present invention is replaced with isopropyl ether, and other steps are the same as the examples of the present invention. It is found that the purity of the obtained ursodeoxycholic acid product is far lower than that of the examples of the present invention, and the high yield of the present invention cannot be achieved to obtain the purity. Greater than 99% ursodeoxycholic acid. The specific operation steps are as follows:

10g of 90% pure ursodeoxycholic acid crude product was dissolved in a mixed solution of isopropyl ether (60mL) and methanol (5mL), stirred and warmed up to 60°C, added 4-dimethylaminopyridine (3.2g), and React at 65°C for 1.5h, then cool the reaction solution, stir at 0-5°C for 1h, filter with suction, wash the filter cake with isopropyl ether (10mL), and dry in vacuo to obtain 4-dimethyl ursodeoxycholic acid Pyridinium ammonium salt (11.3 g). Suspend the 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in water (150 mL), add 2 mol/L sodium hydroxide aqueous solution, adjust the pH to 12.0, stir at 20-25 °C for 1 h; add dropwise 10 % dilute hydrochloric acid to adjust the pH to 2.0, and stirred at 20-25°C for 1h; filtered, collected the filter cake and washed with water, and dried in vacuum to obtain 8.6g of ursodeoxycholic acid, with a liquid phase purity of 95%. The ursodeoxycholic acid obtained by this method The purity of oxycholic acid product is far lower than the embodiment of the present invention.

The present invention treats crude ursodeoxycholic acid by 4-dimethylaminopyridine, not only the operation method is simple, but also the purification yield of ursodeoxycholic acid can reach up to 97.1%, and the product has high purity (liquid phase purity>99%). Therefore, the purification method of ursodeoxycholic acid described in the present invention is more efficient, simpler and more industrially valuable.

The key technology of the present invention that can realize high-efficiency purification of ursodeoxycholic acid is to select 4-dimethylaminopyridine as the base in a specific solvent, and obtain 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid in high yield , and then undergo acid hydrolysis to obtain pure ursodeoxycholic acid in high yield.

The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be imagined by those skilled in the art are all included in the invention, and the appended claims are the protection scope.

Claims

A method for purifying ursodeoxycholic acid, characterized in that the method comprises the following steps:

A. Preparation of 4-lutidine ammonium salt of ursodeoxycholic acid

Dissolve the crude product containing ursodeoxycholic acid in the mixed solution of the first solvent and the second solvent, stir and heat up to 55-70°C, add 4-dimethylaminopyridine DMAP, heat up and reflux for 1-4h, and slowly cool down, Stir at 0-5°C for 0.5-4h, filter with suction, wash the filter cake with the first solvent, and dry to obtain 4-dimethylpyridinium ammonium salt of ursodeoxycholic acid;

B. Hydrolysis of 4-lutidinium salt of ursodeoxycholic acid

Suspend the 4-lutidine ammonium salt of ursodeoxycholic acid obtained in step A in water, add alkali to adjust the pH to 12.0-12.5, stir at 20-25°C for 1-4h; add acid dropwise Adjust the pH to 2.0-2.5, stir at 20-25°C for 1-4h; filter, collect the filter cake, wash with water, and dry to obtain pure ursodeoxycholic acid; the reaction process of the purification method is as shown in route (I) Show:
The method for purifying ursodeoxycholic acid according to claim 1, wherein in step A, the first solvent is acetone; the second solvent is selected from one or more of tetrahydrofuran, methanol, and ethanol kind.
The method for purifying ursodeoxycholic acid according to claim 1, wherein in step A, the amount of 4-dimethylaminopyridine added is 0.31-0.47 times the weight of the crude ursodeoxycholic acid .
The purification method of ursodeoxycholic acid according to claim 1, is characterized in that, the first solvent volume (milliliter) number that adds is 4-8 times of ursodeoxycholic acid crude product weight (gram) number; The second solvent volume (milliliter) number that adds is 0.3-1 times of ursodeoxycholic acid crude product weight (gram); The volume (milliliter) number of the first solvent of described washing filter cake is ursodeoxycholic acid 1-3 times the weight (grams) of crude acid.
The purification method of ursodeoxycholic acid according to claim 1, is characterized in that, in step B, the volume (milliliter) of the water that the 4-lutidine ammonium salt of ursodeoxycholic acid is suspended uses It is 5-20 times the weight (grams) of crude ursodeoxycholic acid.
The method for purifying ursodeoxycholic acid according to claim 1, wherein in step B, the alkali is one or more of sodium hydroxide, potassium hydroxide, and lithium hydroxide.
The method for purifying ursodeoxycholic acid according to claim 1, wherein in step B, the acid is one or more of hydrochloric acid, sulfuric acid, phosphoric acid, and acetic acid.
The purification method of ursodeoxycholic acid according to claim 1, characterized in that, in step B, the concentration of the alkali is 1-8mol/L; the volume fraction of the acid is 10-90%; the The volume (ml) of the water for washing the filter cake is 1-5 times the weight (gram) of the crude ursodeoxy product.