Unlock instant, AI-driven research and patent intelligence for your innovation.

Purification method for D, L-naproxen

A refining method and crude product technology, applied in the field of refining D, can solve the problems of low refining yield, environmental pollution, and difficult recovery of bottom materials, and achieve the effects of high refining yield and easy recovery.

Active Publication Date: 2012-01-18
ZHEJIANG CHARIOTEER PHARMA
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a kind of D, the refining method of L-naproxen, especially a kind of refining D based on pKa value, the method of L-naproxen, to overcome refining D, produce side effects when L-naproxen Product, low yield of refining, difficult recovery of bottom material, major defects of environmental pollution

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Purification method for D, L-naproxen

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] In a flask with stirring and reflux, use 160g of water as a solvent, add 20.0g of D,L-naproxen crude product and 5.0g of sodium hydroxide, heat until completely dissolved, add hydrochloric acid (concentration 10-15%) dropwise to adjust the pH value to 5.8. Heated to 80°C, suction filtered, and dried to obtain 18.7 g of pure D, L-naproxen. By analyzing the content of the crude product as 96.5%, and the purity of the pure product as 99.0%, the refined yield is calculated to be 95.9%.

[0020] Theoretical mass: 19.3g

[0021] Actual Yield: 95.9%

Embodiment 2

[0023] In a flask with stirring and reflux, use 180g of water as a solvent, add 18.0g of D,L-naproxen crude product and 4.5g of sodium hydroxide, heat until completely dissolved, add hydrochloric acid (concentration 10-15%) dropwise to adjust the pH value to 5.5. Heated to 83°C, suction filtered, and dried to obtain 16.9 g of pure D, L-naproxen. Through the analysis of 96.7% of the crude product and 99.2% of the pure product, the refined yield is calculated to be 96.3%.

[0024] Theoretical mass: 17.4g

[0025] Actual yield: 96.3%

Embodiment 3

[0027] In a flask with stirring and reflux, use 180g of water as a solvent, add 20.0g of D,L-naproxen crude product and 5.0g of sodium hydroxide, heat until completely dissolved, add hydrochloric acid (concentration 10-15%) dropwise to adjust the pH value to 5.7. Heated to 85°C, suction filtered, and dried to obtain 18.1 g of pure D, L-naproxen. By analyzing the purity of 93.5% of the crude product and 99.0% of the pure product, the refined yield is calculated to be 95.8%.

[0028] Theoretical mass: 18.7g

[0029] Actual yield: 95.8%

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for refining D, L-naproxen. The preparation method is as follows: adding a D,L-naproxen crude product and an alkali compound into a reaction vessel, taking water as a solvent, and heating and dissolving the D,L-naproxen crude product and the alkali compound; using acid to regulate the PH value to acidity; and carrying out filtration on dissolved substances at a temperature controlled between 20 and 100 DEG C, and drying filter residue to obtain the purified product of the D, L-naproxen. As the refining method takes the water as the solvent, the method has the advantages of environmental protection, easily reclaimed bed charge, and higher refining yield.

Description

(1) Technical field [0001] The invention relates to a method for refining carboxylic acid, in particular to a method for refining D, L-naproxen. (2) Background technology [0002] D, L-naproxen is the key intermediate for preparing naproxen, and its structural formula is as follows: [0003] [0004] D, L-naproxen refining methods mainly include: methanol recrystallization method, methanol and water mixed recrystallization method. Such as Chinese patent CN92102703.6, Zhai Weixu and Zhao Peiqing propose to use methanol recrystallization method and methanol and water mixed recrystallization method. For these two kinds of refining methods, one, during solid-liquid separation, the solvent loss is large, causing waste of resources and polluting the environment; two, adopting alcohol solvents such as methanol to refine carboxylic acid is easy to produce ester impurities, affecting product quality; three, Increase the solvent recovery process and consume energy. (3) Contents...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07C59/64C07C51/42
Inventor 蒲通韩乾范一陈恬杨益富王乃星李东兴
Owner ZHEJIANG CHARIOTEER PHARMA
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com