Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation method for etodolac

A technology of etodolac and methyl acetate, applied in directions such as organic chemistry, can solve the problems of unsuitability for industrial production and high cost, and achieve the effects of easy control, low production cost and high purity

Inactive Publication Date: 2007-12-12
SHANDONG XINHUA PHARMA CO LTD
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because the hydrolysis process uses a large amount of potassium hydroxide, the acidification and crystallization process requires a large am

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
  • Preparation method for etodolac

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Step A: Add 89 g of methyl etodolac, 30 ml of methanol and 150 ml of water into a 1000 ml four-necked reaction flask equipped with a stirrer and a thermometer, add 16 g of sodium hydroxide under stirring, and react at reflux with stirring for 30 minutes. After the reaction was completed, 300 ml of water was added to the reaction solution, dilute hydrochloric acid was added dropwise to pH 3-4 at room temperature, filtered and washed to obtain 84 g (yield 98.86%) of crude etodolac.

[0020] Step B: Add 84 g of crude etodolac in a 1000 ml four-necked reaction flask equipped with a stirrer and a thermometer, add aqueous sodium hydroxide solution (250 ml of water and 13 g of sodium hydroxide) while stirring, filter and wash after dissolving. The filtrate was added with 125ml ethanol, acidified with dilute hydrochloric acid to PH=3~4, filtered, washed, and dried to obtain 83g (yield 98.81%) etodolac.

Embodiment 2

[0022] Step A: Add 89 g of methyl etodolac, 30 ml of methanol and 150 ml of water into a 1000 ml four-necked reaction flask equipped with a stirrer and a thermometer, add 25 g of sodium hydroxide while stirring, and react at reflux with stirring for 30 minutes. After the reaction was completed, 300 ml of water was added to the reaction solution, dilute hydrochloric acid was added dropwise to pH 2-3 at room temperature, filtered and washed to obtain 84.5 g (yield 99.45%) of crude etodolac.

[0023] Step B: Same as Step B of Example 1.

Embodiment 3

[0025] Step A: Add 89 g of methyl etodolac, 30 ml of methanol and 210 ml of water into a 1000 ml four-necked reaction flask equipped with a stirrer and a thermometer, add 16 g of sodium hydroxide while stirring, and react at reflux with stirring for 60 minutes. After the reaction was completed, 420 ml of water was added to the reaction solution, dilute hydrochloric acid was added dropwise to pH 2-3 at room temperature, filtered and washed to obtain 84.2 g (yield 99.09%) of crude etodolac.

[0026] Step B: Same as Step B of Example 1.

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 provides a new process of preparing indoles steroidal antiphlogistic analgesic drug 1, 8- diethyl- 1, 3, 4, 9- tetrahydropyran [3, 4- b] indole- 1- acetate compound. It comprises following steps: A. hydrolyzing and crystallizing 1, 8- diethyl- 1, 3, 4, 9- tetrahydropyran [3, 4- b] indole- 1- acetate methyl ester in alcoholic solution and caustic solution, filtering and getting coarse edetic acid; B. dissloving got coarse product in caustic solution, filtering, ading alcohol, crystallizing, filtering, washing, drying and getting refined edetic acid. The invention is characterized by low acid consumption, little three waste, simple operation, stable process, high productivity, good quality, low production cost and suitability for industrial production.

Description

Technical field [0001] The invention relates to a preparation of indole non-steroidal anti-inflammatory from 1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetate New preparation process of analgesic etodolac compound. Background technique [0002] Etodolic acid, whose chemical name is 1,8-Diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indol-1-aceticacid(1,8-diethyl-1,3,4, 9-Tetrahydropyrano[3,4-b]indole-1-acetic acid), used to treat rheumatoid arthritis, rheumatoid arthritis, osteoarthritis and postoperative pain, with strong analgesic effect. [0003] US Patent No. 6,006,741 discloses an existing preparation process, the steps of which are hydrolysis reaction of methyl etodolac in a solution composed of water and isopropanol in the presence of a large amount of potassium hydroxide. Since the hydrolysis process uses a large amount of potassium hydroxide, the acidification crystallization process requires a large amount of hydrochloric acid for neutralization, which generates a lar...

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
IPC IPC(8): C07D491/04
Inventor 朱连博王冲皇甫传青
Owner SHANDONG XINHUA PHARMA CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com