Method for preparation of carsalam

A kind of compound and reaction technology, applied in the field of preparing Kasalan

Pending Publication Date: 2021-12-14
LONZA GUANGZHOU NANSHA LTD
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] There is a need for a process for the preparation of casalan in high yield and high purity, but with fewer disadvantages than the process disclosed in WO 00 / 46182A1

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
  • Method for preparation of carsalam
  • Method for preparation of carsalam
  • Method for preparation of carsalam

Examples

Experimental program
Comparison scheme
Effect test

example

[0064] abbreviation

[0065] eq. Equivalent, eq, molar equivalent, if not otherwise stated

[0066] Material

[0067] Diethyl carbonate Acros (Thermo Fisher Scientific), 99%

[0068] Salicylamide Macklin Inc., Shanghai, China, 99%

[0069] Analytical method

[0070] HPLC Method for Determining the Purity of Casaram

[0071] Instrument parameters

[0072]

[0073]

[0074] blank : Acetonitrile / water (1 / 1, v / v)

[0075] sample solution

[0076]

[0077] Stability: The solution is stable within 2 days at 4°C

[0078]

example 1

[0080] A 1.5 L reactor was charged with 253 g of diethyl carbonate (2.15 mol, 3.0 eq) and 100 g of salicylamide (0.715 mol, 1.0 eq). The mixture was a suspension and stirred for 15 minutes. Then 309 g of 20 wt% EtONa / EtOH (0.93 mol, 1.3 equiv) were charged into the reactor. The reaction mixture became a clear solution. The reaction mixture was heated to 80°C and stirred at 80°C for 2 hours. A white precipitate was observed. The reaction mixture was cooled to 50 °C. 387 g of water were added and the reaction mixture was stirred for about 15 minutes until it became a clear solution. Then 109 g of 12M HCl (1.07 mol, 1.5 equiv) was added dropwise to the reactor over 1 hour, and a precipitate formed when 12M HCl was added. The reaction mixture was cooled to 0 °C within 2 hours. The suspension was filtered to obtain a filter cake. 231 g of ethanol was added to the reactor and stirred for 15 minutes, and the filter cake was washed with ethanol from the reactor. The filter cak...

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 preparation of Carsalam by a reaction of salicylamide with diethyl carbonate in the presence of an alkali ethoxide.

Description

[0001] The present invention discloses a method for preparing Carsalam by reacting salicylamide with diethyl carbonate in the presence of alkali metal ethoxide. Background technique [0002] Casalan is a pain reliever medicine. [0003] WO 00 / 46182 A1 discloses in Example 1 the preparation of casalan from salicylamide and ethyl chloroformate in pyridine and acetonitrile solvents in a yield of 85%. [0004] Ethyl chloroformate is a highly toxic chemical whose use is regulated (e.g. in China) and thus poses a risk to the environment, especially to workers during production. In addition, it is moisture sensitive and reacts with water, requiring corresponding measures when handling it. [0005] The use of two solvents, pyridine and acetonitrile, adds to the cost of the process, as these solvents have to be discarded in some way or they have to be recycled, both of which again generate costs. [0006] There is a need for a process for the preparation of casalan in high yield and ...

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 Applications(China)
IPC IPC(8): C07D265/22
CPCC07D265/26C07D265/20
Inventor 林幸邦周吉
Owner LONZA GUANGZHOU NANSHA LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap