Preparation method of 5-bromobenzofuran

A furan and bromobenzene technology, applied in the field of organic synthesis, can solve the problems of expensive reagents, high cost, and limited substrates, and achieve the effects of easy industrial scale-up, reduced production costs, and avoiding pollution

Active Publication Date: 2014-04-16
SHANDONG YOUBANG BIOCHEM TECH
View PDF1 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Traditional methods have played an important role in the synthesis of biologically active benzofurans, but there are generally problems such as long routes, harsh substrate and reaction conditions, and limited expansion of substituted functional groups.
Using palladium and other precious metals as catalysts to synthesize benzofuran can overcome the shortcomings of traditional synthesis methods, and the yield has been further improved, but the cost is higher
In recent years, the cheap transition metal copper has gradually become a new hotspot of people's research. The research on using copper as a catalyst to synthesize benzofuran has achieved relatively gratifying results, but there are still limitations in substrates and expensive reagents, etc. shortcoming
Although these achievements are very successful, their industrial production has encountered great challenges, and the heavy metal catalysts used will cause pollution to the environment

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 of 5-bromobenzofuran

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019]

[0020] Add 1,4-dioxane (800 mL) into a 2000 mL three-necked round bottom flask, then add p-bromophenol (210 g, 1.213 mol), potassium carbonate (750 g, 5.426 mol) and 2- Bromoacetaldehyde dimethyl acetal (300 g, 1.775 mol). Stirring was started and heated to reflux for 24 hours. TLC and GC followed the reaction. After the reaction was complete, most of the 1,4-dioxane was distilled off. Add 600 mL each of water and ethyl acetate to the residue, stir the mixture for 30 minutes, and separate the organic phase. The aqueous phase was extracted with 200 mL of ethyl acetate, and the combined organic phases were dried overnight with sodium sulfate. The obtained crude product (340 g) was directly used in the next reaction.

[0021] Add chlorobenzene (1200 mL) to a 5000 mL three-necked round-bottomed flask, then add the above crude product 1-bromo-4'-(2,2-dimethoxyethyl)benzene (340 g), phosphoric acid (850g). Stirring was started and heated to reflux for 24 hours. TL...

Embodiment 2

[0023] Add N,N-dimethylformamide (800 mL) into a 2000 mL three-necked round bottom flask, then add p-bromophenol (210 g, 1.213 mol), potassium carbonate (750 g, 5.426 mol) and 2 -Bromoacetaldehyde dimethyl acetal (300 g, 1.775 mol). Stirring was started and heated to reflux for 20 hours. TLC and GC followed the reaction. After the reaction was completed, most of the N,N-dimethylformamide was distilled off. Add 800 mL each of water and ethyl acetate to the residue, stir the mixture for 60 minutes, and separate the organic phase. The aqueous phase was extracted twice with 300 mL of ethyl acetate. After combining the organic phases, the organic phase was washed with water (300 mL) twice and dried overnight with sodium sulfate. The obtained crude product (350 g) was directly used in the next reaction.

[0024] Add chlorobenzene (1200 mL) to a 5000 mL three-necked round-bottomed flask, then add the above crude product 1-bromo-4'-(2,2-dimethoxyethyl)benzene (350 g), phosphoric a...

Embodiment 3

[0026] Add N,N-dimethylformamide (800 mL) into a 2000 mL three-necked round bottom flask, then add p-bromophenol (210 g, 1.213 mol), potassium carbonate (750 g, 5.426 mol) and 2 - Chloroacetaldehyde dimethyl acetal (222 g, 1.78 mol). Stirring was started and heated to reflux for 28 hours. TLC and GC followed the reaction. After the reaction was completed, most of the N,N-dimethylformamide was distilled off. Add 800 mL each of water and ethyl acetate to the residue, stir the mixture for 45 minutes, and separate the organic phase. The aqueous phase was extracted twice with 300 mL of ethyl acetate. After combining the organic phases, the organic phase was washed with water (300 mL) twice and dried overnight with sodium sulfate. The obtained crude product (290 g) was directly used in the next reaction.

[0027] Add chlorobenzene (1000 mL) in a 5000 mL three-necked round-bottomed flask, then add the above crude product 1-chloro-4'-(2,2-dimethoxyethyl)benzene (290 g), phosphoric...

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 field of organic synthesis, and particularly relates to a preparation method of 5-bromobenzofuran. The preparation method of 5-bromobenzofuran comprises the following steps: p-bromophenol and 2-bromoacetaldehyde dimethyl acetal or 2-chloroacetaldehyde dimethyl acetal react for several hours at a proper temperature in the presence of proper solvent and alkali to generate 1-bromo-4'-(2,2-dimethoxyethyl) benzene; the 1-bromo-4'-(2,2-dimethoxyethyl) benzene is heated in the corresponding solvent in the presence of acid, and experiences a cyclization reaction; the product is purified to obtain 5-bromobenzofuran. The method provided by the invention has the beneficial effects that 5-bromobenzofuran is prepared by a two-step process in the reaction, the operation is simple and convenient, the production cost is reduced, and industrial large-scale production is easy to realize; meanwhile, environmental pollution caused by a heavy metal catalyst is avoided.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a preparation method of 5-bromobenzofuran. Background technique [0002] Benzofuran and its derivatives are very important organic compounds, which have high biological activity and widely exist in the framework of many natural products. Therefore, the synthesis of benzofuran and its derivatives has received extensive attention. There are many literatures reporting the synthesis of benzofuran ring. The classic synthesis of benzofuran is obtained by O-alkylation of salicylaldehyde with chloroacetic acid followed by dehydration. In recent years, it is also obtained by O-alkylation of phenol and its derivatives with chloroacetaldehyde or bromoacetaldehyde, and then dehydration under the action of acid. [0003] Benzofuran compounds have various biological activities such as antihistamine, antitumor and antiarrhythmia, and many of these active compounds are expected to become drugs ...

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): C07D307/79
CPCC07D307/79
Inventor 韩猛曹惊涛来新胜
Owner SHANDONG YOUBANG BIOCHEM TECH
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