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

Preparation method of nitrobenzyl bromide

A technology of o-nitrobenzyl bromide and o-nitrotoluene, which is applied in the field of preparation of o-nitrobenzyl bromide, can solve the problems of slow reaction rate and unsuitability for industrial production, and achieve the advantages of simple operation, high yield and low content Effect

Active Publication Date: 2018-05-25
SOUTHEAST UNIV
View PDF4 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[CN103641722A] such as Liu Fang [CN103641722A] adopt hydrogen bromide / hydrogen peroxide solution as bromination reagent, azobisisobutyronitrile is catalyst, polyethylene glycol PEG600 is phase transfer catalyst, and reaction yield is 79%, and this technique does not use Organic solvents, catalysts can be biodegradable, but the reaction rate is slow, not suitable for industrial production

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 nitrobenzyl bromide
  • Preparation method of nitrobenzyl bromide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Weigh 6.85 grams of o-nitrotoluene and dissolve in 130 grams of dichloromethane, add 13.16 grams of 40% hydrogen bromide solution, 0.82 grams of azobisisobutyronitrile, and 0.81 grams of anhydrous ferric chloride to the system, and stir Heat to reflux, add 7.37 g of 30% hydrogen peroxide solution dropwise at 1 drop / min, stir and reflux for 2 hours, cool to room temperature, and separate the organic phase, which is o-nitrobenzyl bromide. As detected by HPLC, the yield was 86.31%, and the purity was 89.11%.

Embodiment 2

[0021] Weigh 6.85 grams of o-nitrotoluene and dissolve in 130 grams of dichloromethane, add 15.19 grams of 40% hydrogen bromide solution, 0.82 grams of azobisisobutyronitrile to the system, add 0.89 grams of cobalt acetate, stir and heat to Reflux, and dropwise add 8.50 g of 30% hydrogen peroxide solution at 2 drops / min, stir and reflux for 2 hours, cool to room temperature, and separate the organic phase, which is o-nitrobenzyl bromide. As detected by HPLC, the yield was 82.77%, and the purity was 91.11%.

Embodiment 3

[0023] Weigh 6.85 grams of o-nitrotoluene and dissolve in 130 grams of dichloromethane, add 17.21 grams of 40% hydrogen bromide solution, 0.82 grams of azobisisobutyronitrile to the system, add 0.68 grams of zinc chloride, stir and heat to reflux, and dropwise added 9.63 g of 30% hydrogen peroxide solution at 2 drops / min, stirred and refluxed for 2 hours, cooled to room temperature, and separated the organic phase, which was o-nitrobenzyl bromide. As detected by HPLC, the yield was 81.72%, and the purity was 93.83%.

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 preparation method of nitrobenzyl bromide. The preparation method comprises the following steps of: step 1, dissolving ortho-nitrotoluene in halohydrocarbon, sequentially adding a hydrogen bromide solution, an initiator and lewis acid, continuing stirring and heating for backflow reaction, and step 2, dropwise adding a hydrogen peroxide solution into a reaction system instep 1 at a speed of 1-2 drops per min, after the backflow reaction for 1-3h, performing natural cooling, stopping stirring, and performing separation to form an organic phase, namely nitrobenzyl bromide. The method takes ortho-nitrotoluene as a raw material and hydrogen bromide as a bromine source; the hydrogen peroxide solution is added as an oxidant; the initiator and lewis acid are added for ortho-nitrotoluene bromination reaction to generate nitrobenzyl bromide; the preparation method is easy and simple to operate and high in yield; and a content of a byproduct, namely o-nitrocyclite is low.

Description

technical field [0001] The invention relates to the field of preparation of o-nitrobenzyl bromide, in particular to a preparation method of o-nitrobenzyl bromide. Background technique [0002] O-nitrobenzyl bromide, also known as 2-nitrobenzyl bromide, English name: 2-Nitrobenzyl bromide, is an important intermediate for the synthesis of a new broad-spectrum fungicide - pyraclostrobin, and its structural formula is as follows: [0003] [0004] O-nitrobenzyl bromide is an organic fine chemical intermediate, which is widely used in organic synthesis of medicine, pesticides, dyes, etc. In the field of medicine, o-nitrobenzyl bromide is an important intermediate in the synthesis of cardiovascular disease drugs such as nifedipine, nisoldipine, and encaramide, and can be used to synthesize o-nitrostyrenes and o-nitrocinnamic acids. . In the field of pesticides, o-nitrobenzyl bromide is a key intermediate in the synthesis of pyraclostrobin and other pesticides, and it is also...

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): C07C201/12C07C205/11
CPCC07C201/12C07C205/11
Inventor 王明亮王慧敏彭景杨闪光刘晶晶
Owner SOUTHEAST UNIV
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