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A kind of refining method of pentoxifylline recovered product

A technology of pentoxifylline and refining method, which is applied in the field of refining pentoxifylline recovered products, can solve problems such as unreachable single impurity, failure to meet finished product standards, poor impurity removal effect, etc., and achieve good results

Active Publication Date: 2021-05-14
CSPC INNOVATION PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] It can be seen from the above-mentioned patents that the refining of xanthine products mainly adopts dissolution in an alkaline environment, adding carbon and decolorizing with a reducing agent, and then acidifying and crystallizing to obtain the finished product. The inventor used the above two methods to refine the recovered product of pentoxifylline. Unable to reach below 0.1%
[0009] The above-mentioned refining method is not effective in removing impurities, and it still cannot reach the finished product standard in the Pharmacopoeia after several times of refining

Method used

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  • A kind of refining method of pentoxifylline recovered product
  • A kind of refining method of pentoxifylline recovered product
  • A kind of refining method of pentoxifylline recovered product

Examples

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Effect test

Embodiment 1

[0030] 20g of pentoxifylline recovered product (maximum single impurity 4.02%, total impurity 8.25%) was dissolved in water, added 30% liquid caustic soda to adjust pH value to 12, added reducing agent sodium triacetoxyborohydride 1.0g, kept at 80°C for 1h, After filtration, the temperature is lowered to below 20 °C to obtain an alkaline solution. The alkaline solution was mixed with chloroform, left to stand for layers, and the organic phase was evaporated to obtain a viscous liquid. Then add methanol to dissolve the viscous liquid, add charcoal and keep it at reflux temperature for 1 hour, then filter the charcoal by hot filtration. When the temperature drops to room temperature, a large amount of pentoxifylline is precipitated. After cold filtration and drying, the finished product is obtained. The yield is 81.2%, the maximum single impurity is 0.06%, and the total impurity is 0.40%.

Embodiment 2

[0032] 20g of pentoxifylline recovered product (maximum single impurity 3.81%, total impurity 7.63%) was dissolved in water, 30% potassium hydroxide solution was added to adjust the pH value to 14, 0.50 g of reducing agent sodium triacetoxyborohydride was added, and the temperature was kept at 80°C 1h, after filtration, the temperature was lowered to below 20 °C to obtain an alkaline solution. The alkaline solution was mixed with dichloromethane, left to stand for layers, and the organic phase was evaporated to obtain a viscous liquid. Then add methanol to dissolve the viscous liquid, add charcoal and keep it at reflux temperature for 1 hour, then filter the charcoal by hot filtration. When the temperature drops to room temperature, a large amount of pentoxifylline is precipitated. After cold filtration and drying, the finished product is obtained. The yield is 80.9%, the maximum single impurity is 0.07%, and the total impurity is 0.44%.

Embodiment 3

[0034] 20g of pentoxifylline recovered product (maximum single impurity 4.63%, total impurity 8.37%) was dissolved in water, 50% sodium carbonate solution was added to adjust the pH value to 10, 0.75g sodium triacetoxyborohydride was added as a reducing agent, and the temperature was kept at 80°C for 1h , filtered and cooled to below 20 °C to obtain an alkaline solution. The alkaline solution was mixed with toluene, left to stand for layers, and the organic phase was evaporated to obtain a viscous liquid. Then add chloroform to dissolve the viscous liquid, add charcoal and keep it at reflux temperature for 1h, hot filter to remove the charcoal, drop to room temperature and a large amount of pentoxifylline is precipitated, and the finished product is obtained after cold filtration and drying. The yield is 83.6%, the maximum single impurity is 0.09%, and the total impurity is 0.41%.

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Abstract

The invention discloses a method for purifying a recovered pentoxifylline product, which can reduce the impurity content in the recovered pentoxifylline product, so that the maximum single impurity of the recovered product after being refined is reduced to less than 0.1%, and the total impurity is less than 0.5%, which satisfies The standard of finished pentoxifylline can improve the overall yield and reduce the reaction cost. The refining method comprises the following steps: (1) adding the pentoxifylline recovered product into water under heating conditions, dissolving, adding an alkaline liquid to adjust the pH value to 10-14, adding a reducing agent, keeping the temperature, and then cooling and filtering to obtain an alkaline solution; Wherein, in the pentoxifylline recovered product, mono-impurities < 5%, total impurities < 10%; (2) fully mixing the alkaline solution obtained in step (1) with organic solvent A, leaving it to stand for stratification, and steaming off the organic phase Then obtain a viscous liquid; (3) add organic solvent B to dissolve the above-mentioned viscous liquid, add activated carbon, filter the activated carbon after heat preservation, filter the material after the filtrate is reduced to below 20 DEG C, and dry to obtain pentoxifylline.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a method for purifying a pentoxifylline recovered product. Background technique [0002] Pentoxifylline (Pentoxifylline) is a cerebral circulation and peripheral vascular circulation disorder improving agent, which has the effect of dilating cerebral blood vessels and peripheral blood vessels, and improving the blood circulation of the brain and limbs. In addition, it can improve the oxidative capacity of hypoxic tissues. It is mainly used for the improvement of cerebral circulation after ischemic stroke, and can also be used for the treatment of peripheral vascular diseases, such as chronic vasculitis obliterans accompanied by intermittent claudication, and also for the treatment of duodenal ulcer and viral hepatitis. , venous lower extremity ulcers and other diseases, widely used in clinical medicine. [0003] Pentoxifylline is obtained by the condensation of theobromine and ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D473/10
CPCC07D473/10
Inventor 冯志军谢丽莎赵旭祁文敏解聪聪
Owner CSPC INNOVATION PHARMA
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