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

Preparation method for 5,5-dimethylbarbituric acid as impurity of butalbital

A technology of dimethyl barbituric acid and butalbital, which is applied in the field of drug synthesis to achieve the effects of simple post-processing, easy availability of raw materials, and high purity

Inactive Publication Date: 2017-07-18
SHANDONG XINHUA PHARMA CO LTD
View PDF4 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are no published patents or literature reports on the preparation of 5,5-dimethylbarbituric acid

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 5,5-dimethylbarbituric acid as impurity of butalbital
  • Preparation method for 5,5-dimethylbarbituric acid as impurity of butalbital
  • Preparation method for 5,5-dimethylbarbituric acid as impurity of butalbital

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] (1) Preparation of 2,2-dimethylmalonate diethyl ester

[0026] Add sodium ethoxide (101.9g, 1.5mol) into absolute ethanol (750mL), stir until completely dissolved, add diethyl methylmalonate (174.19g, 1mol) dropwise at 20°C, and drop it within 1h After that, keep stirring at 20°C for 0.5h. Then continue to add iodomethane (156.1 g, 1.1 mol) dropwise at 20°C, and control the dropwise completion within 1 h. After that, the temperature was raised to 80 degrees, and the temperature was kept at reflux for 10 hours. Heating was stopped, all the ethanol was distilled off under reduced pressure, and then 800 ml of distilled water was added to the residue to dissolve it. After dissolving, it was extracted twice with 2*800ml ethyl acetate, the ethyl acetate layers were combined, dried with anhydrous sodium sulfate, filtered with suction, and the ethyl acetate was concentrated to obtain 127.6g of light yellow oil. The purity of the crude product is 92.8%, and the yield is 62.89...

Embodiment 2

[0033] (1) Preparation of 2,2-dimethylmalonate diethyl ester

[0034] Add sodium ethoxide (122.3g, 1.5mol) to absolute ethanol (850mL), stir until completely dissolved, add diethyl methylmalonate (174.19g, 1mol) dropwise at 30°C, and drop it within 1h Complete, then continue to insulate and react at 30 degrees for 1h. Then methyl iodide (170.3 g, 1.2 mol) was added dropwise at 30°C, and the drop was completed within 1 h. After that, the temperature was raised to 80 degrees, and the temperature was kept at reflux for 15 hours. Heating was stopped, all the ethanol was distilled off under reduced pressure, and then 800 ml of distilled water was added to the residue to dissolve it. After dissolving, it was extracted twice with 2*800ml ethyl acetate, the ethyl acetate layers were combined, dried with anhydrous sodium sulfate, filtered with suction, and the ethyl acetate was concentrated to obtain 143.36g of light yellow oil. The purity of the crude product is 98.8%, and the yiel...

Embodiment 3

[0040] (1) Preparation of 2,2-dimethylmalonate diethyl ester

[0041] Add sodium ethoxide (163.1g, 2mol) into absolute ethanol (950mL), stir until completely dissolved, add diethyl methylmalonate (174.19g, 1mol) dropwise at 40°C, and control the dropwise completion within 1h , and then continue to insulate the reaction at 40 degrees for 2h. Then iodomethane (184.5 g, 1.3 mol) was added dropwise at 40°C, and the drop was completed within 1 h. Afterwards, the temperature was raised to 80 degrees, and the temperature was kept at reflux for 20 hours. Heating was stopped, all the ethanol was distilled off under reduced pressure, and then 800 ml of distilled water was added to the residue to dissolve it. After dissolving, extract twice with 2*800ml of ethyl acetate, combine the ethyl acetate layers, dry with anhydrous sodium sulfate, filter with suction, concentrate the ethyl acetate to obtain 145.68g of light yellow oil. The purity of the crude product is 98.9%, and the yield is...

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 belongs to the technical field of pharmaceutical synthesis, and particularly relates to a preparation method for 5,5-dimethylbarbituric acid as an impurity of butalbital. In a sodium ethoxide / ethanol system, diethyl methylmalonate is dripped, and stirring is carried out; iodomethane is then dripped, and after reaction, crude 2,2-diethyl dimethylmalonate is obtained; the obtained crude 2,2-diethyl dimethylmalonate reacts with urea in a sodium ethoxide / ethanol system, and after reaction is completed, 5,5-dimethylbarbituric acid is obtained by post-processing. The raw materials of the invention are easy to obtain, the preparation method is easy to operate, the safety of reaction is high, post-processing is simple, the purity of prepared 5,5-dimethylbarbituric acid as an impurity of butalbital is high, reaching 99.40 percent or more, and the preparation method has an important guiding significance for the research of butalbital preparations.

Description

technical field [0001] The invention belongs to the technical field of medicine synthesis, and in particular relates to a preparation method of butalbital impurity 5,5-dimethylbarbituric acid. Background technique [0002] During the preparation of butalbital, due to the problem of residual raw materials, there will be a trace amount of 5,5-dimethylbarbituric acid in the finished product. The research on residues of 5,5-dimethylbarbituric acid has important guiding significance for the research of butalbital preparations. At present, there are no published patents or literature reports on the preparation of 5,5-dimethylbarbituric acid. Contents of the invention [0003] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing butalbital impurity 5,5-dimethylbarbituric acid, which has easy-to-obtain raw materials, simple operation, high reaction safety, and simple post-treatment , the prepared 5,5-dimethylbarbi...

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): C07D239/62
CPCC07D239/62
Inventor 张富强常森
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