Purification and salification process of probenecid crude product

Abstract

The invention relates to a process for purifying and salifying a probenecid crude product, which is characterized in that the purpose of removing organic impurities, inorganic impurities and harmful solvent residues in the probenecid crude product is achieved by utilizing the dissolvability difference of probenecid acid and salt thereof and transferring the probenecid acid and the salt thereof in a water phase and an organic phase for many times, and a high-purity probenecid solution is obtained. And reacting the probenecid solution with a salt-forming agent to obtain the probenecid sodium. The purity of the probenecid purified by the process can reach more than 99.9% (HPLC), solid-liquid separation and intermediate drying are not needed in the purification and salification processes, continuous production can be realized, the production period is shortened, and the process is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to a purification and salt-forming process of a crude probenecid product, and belongs to the technical field of raw material drug preparation. Background Art

[0002] Probenecid is a white crystalline powder with a melting point of 198-201°C. It is soluble in acetone, slightly soluble in ethanol and chloroform, and practically insoluble in water. It is soluble in dilute sodium hydroxide solution and practically insoluble in dilute acid. It is odorless and slightly bitter. It is used as an anti-gout medication and adjunct to antibiotic therapy.

[0003] In addition to its role in treating chronic gout, probenecid can also significantly optimize the pharmacokinetic properties of various β-lactam antibiotics. [1] This approach not only significantly reduces the dosage of corresponding antibiotics, thereby lowering the incidence of adverse antibiotic reactions, but also significantly improves the effectiveness and compliance of antimicrobial therapy, reducing the selection of drug-resistant bacteria. The development of combined use of probenecid with various β-lactam antibiotics has extremely important clinical value and also has a very positive social impact in reducing antibiotic use and alleviating bacterial resistance. In 2024, the US FDA approved a new sulopenem prodrug / probenecid combination preparation, and the China Center for Drug Evaluation (CDE) has also approved clinical trials for a cefazolin sodium and probenecid sodium combination injection. Currently, the combination of probenecid (sodium) with various β-lactam antibiotics has become a hot topic and a cutting-edge direction in improving existing antimicrobial drugs.

[0004] Improving the refining or purification process, increasing the purity of active ingredients, and controlling impurity levels are crucial for enhancing drug quality and safety. Extensive experimental and analytical testing data demonstrate that crude probenecid contains significant amounts of organic and inorganic impurities. Organic impurities include p-carboxybenzenesulfonic acid, ethyl probenecid, and propyl probenecid, while inorganic impurities include sodium chloride and sodium acetate. Summary of the Invention

[0005] The present invention provides a process for purifying and salifying crude probenecid. This process utilizes the solubility differences between probenecid acid and its salts to transfer the solution multiple times between aqueous and organic phases, thereby removing organic and inorganic impurities and harmful solvent residues from the crude probenecid product. This process then reacts the solution with a salifying agent to produce probenecid sodium. The purified probenecid achieved a purity exceeding 99.9% (HPLC). The purification and salification processes do not require solid-liquid separation or intermediate drying, enabling continuous production and shortening the production cycle, making it suitable for industrial production.

[0006] The technical solution of the present invention is achieved as follows: a purification and salt-forming process for crude probenecid, characterized in that the specific steps are as follows: 1) Add organic solvent A, purified water, and crude probenecid to a reaction flask in appropriate proportions, stir and heat, then add alkaline solution dropwise to a pH of 8-11 under controlled temperature. Stir thoroughly and allow to stand for stratification. 2) Separate the organic phase, add solvent A to the aqueous phase again, stir thoroughly, let stand, and then separate the organic phase; 3) Add organic solvent B to the aqueous phase in proportion, stir and heat, control the temperature and add acidic solution dropwise until the pH is 5.0-5.4, stir thoroughly and let stand to separate the layers; 4) Separate the aqueous phase, add purified water to the organic phase again, stir thoroughly, let stand, and then separate the aqueous phase to obtain a high-purity probenecid solution; 5) Add 1-3% activated carbon by weight of the crude probenecid to the probenecid solution, decolorize under controlled temperature, and remove the activated carbon by hot filtration; 6) Adding a salt-forming agent in proportion to the decolorized probenecid solution, controlling the temperature for reaction, cooling the solution for crystallization, and centrifuging and drying to obtain probenecid sodium; The organic solvent A in step (1) is one or more of aliphatic hydrocarbons, aromatic hydrocarbons, ethers, and C4-C6 polyols that are immiscible with water, preferably toluene, methyl tert-butyl ether, n-hexane, 1-pentanol, or dichloromethane.

[0007] The alkaline solution in step (1) is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, and sodium isooctanoate. Sodium hydroxide and sodium carbonate are preferred; the pH is 8-11, preferably 9-10.

[0008] In the step (1), the weight ratio of crude probenecid, solvent A, and purified water is 1:1-5:1-5, preferably 1:3:3; The amount of the organic solvent A in the step (2) is 0.5-2 times, preferably 1 time, of the crude probenecid.

[0009] In the step (3), the organic solvent B is a weak polar solvent that is immiscible with water, and is one of methyl tert-butyl ether, n-butanol, 1-pentanol, and octanol, preferably n-butanol, 1-pentanol, and methyl tert-butyl ether; the amount of solvent B used is 3-10 times that of the crude probenecid, preferably 5 times.

[0010] The acidic solution in step (3) is one of hydrochloric acid, acetic acid, and formic acid, preferably acetic acid; the dropping temperature is 40-70°C, preferably 50-60°C.

[0011] The amount of purified water used in step (4) is 1-3 times, preferably 1 time, of the crude probenecid.

[0012] In the step (5), the decolorization temperature is 50-80° C., and the decolorization time is 20-40 min, preferably 30 min.

[0013] In the step (6), the salt-forming agent is one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, and sodium isooctanoate, preferably sodium hydroxide, sodium ethoxide, and sodium isooctanoate; the molar ratio of the salt-forming agent to the crude probenecid is 1.0-1.2, preferably 1.02-1.05; the crystallization temperature is 10-20° C., and the crystallization time is ≥1 h.

[0014] The positive effects of the present invention are as follows: (1) The present invention utilizes the difference in solubility of probenecid and its salts to transfer them multiple times between the aqueous phase and the organic phase to achieve the purpose of purification; the screening of solvent A and solvent B is key in the present invention. Solvent A must have a strong solubility for organic impurities in the crude probenecid product and be immiscible with water; solvent B should have a certain solubility for probenecid. Since probenecid is a weakly polar organic acid, solvent B cannot be a non-polar solvent and cannot be completely miscible with polar solvent water in order to remove inorganic impurities dissolved in water; furthermore, solvent B should also facilitate the salt-forming reaction of probenecid and facilitate the precipitation of probenecid sodium.

[0015] (2) The process conditions of the present invention are simple, and the preparation process does not require solid-liquid separation and the intermediates do not need to be dried, which greatly shortens the preparation cycle and improves production efficiency.

[0016] (3) The present invention does not require centrifugation or drying in the intermediate process, which greatly reduces the investment in production equipment.

[0017] (4) The present invention has been experimentally proven to have a HPLC purity of 99.9% after purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the HPLC chromatogram of the crude probenecid product of Example 1.

[0019] Figure 2 It is the HPLC chromatogram of the purified crude probenecid product in Example 1. DETAILED DESCRIPTION

[0020] The present invention is further described below with reference to the examples.

[0021] Example 1 (Batch No. B42505002) 30 g of toluene, 30 g of purified water, and crude probenecid (purity of crude product is 97.23%) were added. Figure 1Place 10g of the compound (shown as shown) into a 250ml reaction flask, stir and heat. Maintain the temperature at 70-80°C, add 25% sodium hydroxide solution dropwise until the reaction solution has a pH of 9, and continue stirring at 70-80°C for 30 minutes.

[0022] Transfer the reaction mixture to a separatory funnel, let it stand for 30 minutes to separate the layers, and then remove the organic phase. Add 10g of toluene to the aqueous phase again, mix thoroughly, let it stand for 30 minutes, and then remove the organic phase. The aqueous phase was transferred to a 250 ml reaction flask, 50 g of n-butanol was added, the temperature was raised with stirring, and the temperature was controlled at 50-60 °C. 50% acetic acid solution was slowly added dropwise until the pH of the reaction solution reached 5.3, and stirring was continued for 30 min.

[0023] The reaction solution was transferred to a separatory funnel, allowed to stand for 30 minutes, and then the aqueous phase was separated. 10 g of purified water was added to the organic phase again, and the mixture was thoroughly mixed and allowed to stand for 30 minutes. The aqueous phase was separated again to obtain a high-purity probenecid n-butanol solution.

[0024] The probenecid solution was transferred to a 250 ml reaction bottle, 0.3 g of activated carbon was added, and the solution was decolorized at 70-80°C for 30 minutes. The activated carbon was removed by hot filtration.

[0025] After decolorization, 1.04 equivalents of sodium carbonate were added to the probenecid solution and the mixture was refluxed with water for 1 hour. After the reaction, the temperature was lowered to 10-20°C for crystallization for 1 hour. After filtration and drying, 7.9 g of probenecid sodium was obtained with a purity of 99.90% (such as Figure 2 The total yield was 73.3%.

[0026] Example 2 (Batch No. B42505003) Place 30g of n-hexane, 30g of purified water, and 10g of crude probenecid in a 250ml reaction flask, stir and heat. Add 25% sodium hydroxide solution dropwise at 55-65°C until the pH of the reaction solution reaches 10, and continue stirring at 55-65°C for 30 minutes.

[0027] Transfer the reaction mixture to a separatory funnel, let it stand for 30 minutes, and then remove the organic phase. Add 10g of n-hexane to the aqueous phase again, mix thoroughly, let it stand for 30 minutes, and then remove the organic phase. The aqueous phase was transferred to a 250 ml reaction flask, 50 g of methyl tert-butyl ether was added, the temperature was raised with stirring, and the temperature was controlled at 50-55 °C. 50% acetic acid solution was slowly added dropwise until the pH of the reaction solution reached 5.4, and stirring was continued for 30 min.

[0028] The reaction solution was transferred to a separatory funnel, allowed to stand for 30 minutes, and then the aqueous phase was separated. 10 g of purified water was added to the organic phase again, and the mixture was thoroughly mixed and allowed to stand for 30 minutes. The aqueous phase was separated again to obtain a high-purity probenecid methyl tert-butyl ether solution.

[0029] Transfer the probenecid solution to a 250 ml reaction bottle, add 0.2 g of activated carbon, decolorize at 50-55°C for 30 minutes, and remove the activated carbon by hot filtration.

[0030] 1.05 equivalents of sodium isooctanoate were added to the decolorized probenecid solution and refluxed for 1 hour. After the reaction, the temperature was lowered to 10-20°C for crystallization for 1 hour. After filtration and drying, 8.3 g of probenecid sodium was obtained with a total yield of 77.1%.

[0031] Example 3 (Batch No. B42505004) Place 30g of methyl tert-butyl ether, 30g of purified water, and 10g of crude probenecid in a 250ml reaction flask, stir and heat. Add 25% sodium hydroxide solution dropwise at 45-55°C until the pH of the reaction solution reaches 9. Continue stirring at 45-55°C for 30 minutes.

[0032] Transfer the reaction mixture to a separatory funnel, let it stand for 30 minutes to separate the layers, and then remove the organic phase. Add 10g of methyl tert-butyl ether to the aqueous phase again, mix thoroughly, let it stand for 30 minutes, and then remove the organic phase. The aqueous phase was transferred to a 250 ml reaction flask, 50 g of 1-pentanol was added, the temperature was raised with stirring, and the temperature was controlled at 50-60 ° C. 50% acetic acid solution was slowly added dropwise until the pH of the reaction solution reached 5.2, and stirring was continued for 30 min.

[0033] The reaction solution was transferred to a separatory funnel, allowed to stand for 30 minutes, and then the aqueous phase was separated. 10 g of purified water was added to the organic phase again, and the mixture was thoroughly mixed and allowed to stand for 30 minutes. The aqueous phase was separated again to obtain a high-purity probenecid 1-pentanol solution.

[0034] The probenecid solution was transferred to a 250 ml reaction bottle, 0.3 g of activated carbon was added, and the solution was decolorized at 70-80°C for 30 minutes. The activated carbon was removed by hot filtration.

[0035] After decolorization, 1.0 equivalent of sodium hydroxide was added to the probenecid solution and the reaction was carried out at 60-70°C for 1 hour. After the reaction, the temperature was lowered to 10-20°C for crystallization for 1 hour. After filtration and drying, 8.5 g of probenecid sodium was obtained with a total yield of 78.9%.

[0036] Example 4 (Batch No. B42505005) Place 50g of methyl tert-butyl ether, 10g of purified water, and 10g of crude probenecid in a 250ml reaction flask, stir, and heat. Add 25% sodium hydroxide solution dropwise at 40-50°C until the pH of the reaction solution reaches 11. Continue stirring at 40-50°C for 30 minutes.

[0037] Transfer the reaction mixture to a separatory funnel, let it stand for 30 minutes to separate the layers, and then remove the organic phase. Add 5 g of methyl tert-butyl ether to the aqueous phase again, mix thoroughly, let it stand for 30 minutes, and then remove the organic phase. The aqueous phase was transferred to a 250 ml reaction flask, 30 g of 1-pentanol was added, the temperature was raised with stirring, and the temperature was controlled at 50-60 ° C. 50% acetic acid solution was slowly added dropwise until the pH of the reaction solution reached 5.0, and stirring was continued for 30 min.

[0038] The reaction solution was transferred to a separatory funnel, allowed to stand for 30 minutes, and then the aqueous phase was separated. 30 g of purified water was added to the organic phase again, and the mixture was thoroughly mixed and allowed to stand for 30 minutes. The aqueous phase was separated again to obtain a high-purity probenecid 1-pentanol solution.

[0039] The probenecid solution was transferred to a 250 ml reaction bottle, 0.3 g of activated carbon was added, and the solution was decolorized at 70-80°C for 20 minutes. The activated carbon was removed by hot filtration.

[0040] After decolorization, 1.2 equivalents of sodium hydroxide were added to the probenecid solution and reacted at 60-70°C for 1 hour. After the reaction, the temperature was lowered to 10-20°C for crystallization for 1 hour. After filtration and drying, 8.2 g of probenecid sodium was obtained with a total yield of 76.1%.

[0041] Example 5 (Batch No. B42505006) Place 20g of n-hexane, 50g of purified water, and 10g of crude probenecid in a 250ml reaction flask, stir and heat. Add 25% sodium hydroxide solution dropwise at 50-60°C until the reaction solution has a pH of 8. Continue stirring at 50-60°C for 30 minutes.

[0042] Transfer the reaction mixture to a separatory funnel, let it stand for 30 minutes to separate the layers, and then remove the organic phase. Add 20g of n-hexane to the aqueous phase again, mix thoroughly, let it stand for 30 minutes, and then remove the organic phase. The aqueous phase was transferred to a 250 ml reaction flask, 85 g of methyl tert-butyl ether was added, the temperature was raised with stirring, the temperature was controlled at 40-50°C, 50% acetic acid solution was slowly added dropwise until the pH of the reaction solution reached 5.4, and stirring was continued for 30 min.

[0043] The reaction solution was transferred to a separatory funnel, allowed to stand for 30 minutes, and then the aqueous phase was separated. 30 g of purified water was added to the organic phase again, and the mixture was thoroughly mixed and allowed to stand for 30 minutes. The aqueous phase was separated again to obtain a high-purity probenecid methyl tert-butyl ether solution.

[0044] Transfer the probenecid solution to a 250 ml reaction bottle, add 0.3 g of activated carbon, decolorize at 50-55°C for 30 minutes, and remove the activated carbon by hot filtration.

[0045] After decolorization, 1.05 equivalents of sodium isooctanoate were added to the decolorized probenecid solution and refluxed for 1 hour. After completion of the reaction, the temperature was lowered to 10-20°C for crystallization for 1 hour. After filtration and drying, 8.0 g of probenecid sodium was obtained with a total yield of 74.3%.

[0046] Example 6 (Batch No. B42505007) (1) Place 10 g of toluene, 30 g of purified water, and 10 g of crude probenecid in a 250 ml reaction flask, stir, and heat. Control the temperature at 60-70°C. Add 25% sodium hydroxide solution dropwise until the pH of the reaction solution reaches 9. Continue stirring at 60-70°C for 30 min.

[0047] (2) Transfer the reaction mixture to a separatory funnel, let it stand for 30 minutes, and then remove the organic phase. Add 15 g of toluene to the aqueous phase, mix thoroughly, let it stand for 30 minutes, and then remove the organic phase. (3) The aqueous phase was transferred to a 250 ml reaction flask, 100 g of n-butanol was added, and the temperature was raised by stirring. The temperature was controlled at 60-70 °C, and 50% acetic acid solution was slowly added dropwise until the pH of the reaction solution reached 5.3. Stirring was continued for 30 min.

[0048] (4) The reaction solution was transferred to a separatory funnel, allowed to stand for 30 minutes, and then the aqueous phase was separated. 10 g of purified water was added to the organic phase again, and the mixture was thoroughly mixed and allowed to stand for 30 minutes. The aqueous phase was separated again to obtain a high-purity probenecid n-butanol solution.

[0049] (5) Transfer the probenecid solution to a 250 ml reaction bottle, add 0.1 g of activated carbon, decolorize at 70-80°C for 30 minutes, and remove the activated carbon by hot filtration.

[0050] (6) After decolorization, 1.02 equivalents of sodium hydroxide were added to the probenecid solution, and the mixture was refluxed with water for 1 hour. After the reaction, the temperature was lowered to 10-20°C for crystallization for 1 hour. After filtration and drying, 7.96 g of probenecid sodium was obtained, with a total yield of 73.9%.

Claims

1. A purification and salt-forming process for crude probenecid, characterized in that The specific steps are as follows: Add organic solvent A, purified water, and crude probenecid into a reaction flask in proportion, stir and heat, add alkaline solution dropwise to pH 8-11 under temperature control, stir thoroughly, and then stand for stratification; The organic phase was removed, and solvent A was added to the aqueous phase again, and the organic phase was removed after sufficient stirring and standing; Add organic solvent B to the aqueous phase in proportion, stir and heat, control the temperature and add acidic solution dropwise until the pH is 5.0-5.4, stir thoroughly and let stand to separate the layers; The aqueous phase was separated and purified water was added to the organic phase again, and the mixture was stirred thoroughly and allowed to stand, and then the aqueous phase was separated to obtain a high-purity probenecid solution; Add 1-3% of the weight of crude probenecid to the probenecid solution with activated carbon, decolorize under controlled temperature, and remove the activated carbon by hot filtration; After decolorization, a salt-forming agent is added to the probenecid solution in proportion, the temperature is controlled for reaction, the temperature is lowered for crystallization, and the solution is centrifuged and dried to obtain probenecid sodium.

2. The purification and salt-forming process of the crude probenecid product according to claim 1, wherein The organic solvent A in step (1) is one or more of aliphatic hydrocarbons, aromatic hydrocarbons, ethers, and C4-C6 polyols that are immiscible with water.

3. The purification and salt-forming process of the crude probenecid product according to claim 1, characterized in that The alkaline solution in step (1) is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, and sodium isooctanoate; the alkaline solution is added dropwise at a temperature of 40-80° C. and the standing time for stratification is greater than 30 min.

4. The process for purifying and salting crude probenecid according to claim 1, wherein The weight ratio of the crude probenecid, solvent A and purified water in the step (1) is 1:1-5:1-5.

5. The process for purifying and salting crude probenecid according to claim 1, wherein In the step (2), the amount of organic solvent A is 0.5-2 times that of the crude probenecid, and the standing and stratification time is greater than 30 minutes.

6. The process for purifying and salting crude probenecid according to claim 1, wherein The organic solvent B in the step (3) is a weakly polar solvent that is immiscible with water and is one of methyl tert-butyl ether, n-butanol, 1-pentanol, and n-hexane. The amount of solvent B used is 3-10 times that of the crude probenecid.

7. The process for purifying and salting crude probenecid according to claim 1, wherein The acidic solution in step (3) is one of hydrochloric acid, acetic acid, and formic acid, the dropping temperature is 40-70° C., and the standing time for stratification is greater than 30 minutes.

8. The process for purifying and salting crude probenecid according to claim 1, wherein The amount of purified water used in step (4) is 1-3 times that of the crude probenecid, and the standing stratification time is greater than 30 minutes; the decolorization temperature in step (5) is 50-80° C.; and the decolorization time is 20-40 minutes.

9. The process for purifying and salting crude probenecid according to claim 1, wherein The salt-forming agent in step (6) is one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, and sodium isooctanoate, the molar ratio of the salt-forming agent to the crude probenecid is 1.0-1.2, the crystallization temperature is 10-20° C., and the crystallization time is ≥1 h.

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