Method for synthesizing 2-(4-cyclopropoxycarbonylphenyl)-2-methylpropanoic acid

A technology of cyclopropoxycarbonylphenyl and methylpropionic acid, which is applied in the field of synthesizing 2--2-methylpropionic acid, can solve the problems of many steps, low yield and high cost, and achieve simple preparation process , few reaction steps, low production cost

Inactive Publication Date: 2009-11-25
NINGBO INST OF TECH ZHEJIANG UNIV ZHEJIANG
View PDF2 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The method steps in the above two application patent documents are many, the resolution efficiency is low, and the yield is not very high (the product yield in US2002007068 (A1) is about 28%, and the product yield in the Indian patent is about 40%)
[0004] U.S. Patent No. 6,242,606 (B1) discloses that 2-(4-(1-oxo-1-cyclopropyl))-phenyl-2-methylpropanol or 2-(4-(1-oxo-1 - A process for the oxidation of cyclopropyl))-phenyl-2-methylpropanol acetate to prepare 2-(4-cyclopropoxycarbonylphenyl)-2-methylpropionic acid, which not only requires minimal preparation of starting materials Five-step reaction, the cost is high, and the oxidation method that uses precious metal compound ruthenium trichloride as catalyst in the oxidation method will greatly increase the product preparation cost, and the oxidation method that uses acidic potassium permanganate or acidic sodium nitrite as oxidant will bring relatively high Large environmental pollution, low yield of oxidation method using fuming nitric acid as oxidant

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] In a 250 ml three-necked flask, add 16.00 g (0.40 mol) sodium hydroxide and 150 ml anhydrous methanol and stir evenly, then add 15.50 g (0.05 mol) N-methyl-N-methoxy-2- [4-(4-Chlorobutyryl)phenyl]-2-methylpropionamide was dissolved in 50 ml of anhydrous methanol to form a uniformly stirred solution and added dropwise to the three-necked flask. After the addition, the reaction was stirred at 30°C. 18 hours. After the reaction was completed, the anhydrous methanol was evaporated under reduced pressure, 100 ml of water and 100 ml of dichloromethane were added to the residue to separate the layers, and the aqueous layer was extracted twice with 100 ml of dichloromethane respectively. The extracts containing the dichloromethane layer were combined, dried with anhydrous sodium sulfate, filtered, and dichloromethane was evaporated under reduced pressure to obtain the product N-methyl-N-methoxy-2-(4-cyclopropoxycarbonylbenzene Yl)-2-methylpropionamide 13.00 g (0.047 mol), the yield...

Embodiment 2

[0028] Add 20.50g (82%, 0.30mol) of potassium hydroxide and 150ml of anhydrous methanol to a 250ml three-necked flask and stir evenly, then add 15.50g (0.05mol) of N-methyl-N-methoxy while stirring -2-[4-(4-Chlorobutyryl)phenyl]-2-methylpropionamide is dissolved in 50 ml of anhydrous methanol to form a uniformly stirred solution and added dropwise to the three-necked flask. After the addition is complete, at 20 The reaction was stirred at °C for 30 hours. After the reaction was completed, the anhydrous methanol was evaporated under reduced pressure, 100 ml of water and 100 ml of dichloromethane were added to the residue to separate the layers, and the aqueous layer was extracted twice with 100 ml of dichloromethane respectively. The extracts containing the dichloromethane layer were combined, dried with anhydrous sodium sulfate, filtered, and dichloromethane was evaporated under reduced pressure to obtain the product N-methyl-N-methoxy-2-(4-cyclopropoxycarbonylbenzene Yl)-2-methyl...

Embodiment 3

[0031] Add 20.00g (0.50mol) sodium hydroxide and 150ml absolute ethanol into a 250ml three-necked flask, stir evenly, then add 15.50g (0.05mol) N-methyl-N-methoxy-2 while stirring -[4-(4-Chlorobutyryl)phenyl]-2-methylpropionamide is dissolved in 50 ml of absolute ethanol to form a uniformly stirred solution and added dropwise to the three-necked flask. After the addition is complete, at 50°C The reaction was stirred for 30 hours. After the completion of the reaction, the absolute ethanol was evaporated under reduced pressure, 100 ml of water and 100 ml of dichloromethane were added to the residue to separate the layers, and the aqueous layer was extracted twice with 100 ml of dichloromethane respectively. The extracts containing the dichloromethane layer were combined, dried over anhydrous sodium sulfate, filtered, and dichloromethane was evaporated under reduced pressure to obtain the product N-methyl-N-methoxy-2-(4-cyclopropoxycarbonylphenyl) -2-Methylpropionamide 12.65 g (0.046...

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 synthesizing 2-(4-cyclopropoxycarbonylphenyl)-2-methylpropanoic acid, comprising the steps of adding an alkali metal hydroxide in an alcohol solvent, dripping the alcohol solvent of N-methyl-N-methoxyl-2-[4-(4-chlorobutyryl)phenyl]-2-methacrylamide in the alcohol solvent, agitating and reacting for 10-30h at 20-50 DEG C, extracting, drying and filtering to obtain N-methyl-N-methoxyl-2-(4-cyclopropoxycarbonylphenyl)-2-methacrylamide; adding the N-methyl-N-methoxyl-2-(4-cyclopropoxycarbonylphenyl)-2-methacrylamide in the alcohol solvent of the alkali metal hydroxide, refluxing and reacting for 20-40h, and adjusting the pH of the reaction mixture to be 3 by hydrochloric acid, extracting, drying, filtering and removing methylene dichloride to obtain 2-(4-cyclopropoxycarbonylphenyl)-2-methylpropanoic acid. The synthetic method of the invention has the advantages of a few reaction steps, simple preparation technology, high yield, little pollution and lowproduction cost.

Description

Technical field [0001] The invention relates to a method for synthesizing 2-(4-cyclopropoxycarbonylphenyl)-2-methylpropionic acid. Background technique [0002] Allergic diseases are common human diseases, such as allergic rhinitis, chronic sudden rubella, hay fever and so on. Fexofenadine hydrochloride is a new generation of anti-allergic drugs, which is similar to the similar products of astemizole (asimidazole, which was withdrawn from the US market in 1999 due to easy cardiotoxicity), cetirizine, loratadine, etc. In comparison, fexofenadine hydrochloride has the advantages of fast action, high curative effect, and less side effects. 2-(4-Cyclopropoxycarbonylphenyl)-2-methylpropionic acid is an important intermediate for the synthesis of fexofenadine hydrochloride. [0003] There are also many reports on the synthesis method of 2-(4-cyclopropoxycarbonylphenyl)-2-methylpropionic acid, such as the patent application document with publication number US2002007068(A1) and the India...

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): C07C59/86C07C51/06
Inventor 骆成才张华星杨志杰郑志利柴胜利
Owner NINGBO INST OF TECH ZHEJIANG UNIV ZHEJIANG
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