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

Preparation method of 3, 4, 5-trifluoro bromobenzene

A technology of trifluorobromobenzene and trifluoroaniline is applied in the preparation of pesticide intermediates and in the field of medicine, and can solve the problems of side reactions, many impurities in the product, poor regioselectivity, etc., so as to improve yield, reduce by-products, reduce The effect of production costs

Active Publication Date: 2014-02-26
ZHEJIANG LINJIANG CHEM
View PDF8 Cites 21 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This preparation method requires strict control of anhydrous and oxygen-free, and the regioselectivity of the reaction is not good, there are side reactions, and there are many impurities in the product

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 3, 4, 5-trifluoro bromobenzene
  • Preparation method of 3, 4, 5-trifluoro bromobenzene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] In a 500ml three-neck flask, add 14.7g (0.1mol) of 2,3,4-trifluoroaniline, 100ml of water, control the temperature below 10°C, add 19.2g (1.2mol) of bromine dropwise, after the dropwise addition is complete, keep the temperature for 1h. After static separation, an organic oil layer and a water layer were obtained. The organic oil layer was crude 2,3,4-trifluoro-6-bromoaniline, which was used in the next step of reaction; the water layer was collected and recycled.

[0036] Add the crude product of 2,3,4-trifluoro-6-bromoaniline obtained from the above reaction into a 500ml three-necked flask, and add 40ml of 98% concentrated sulfuric acid dropwise under stirring. Add 28ml of sodium nitrite solution with a fraction of 30%. After the dropwise addition, keep it warm for 1 hour and set aside.

[0037] Add 100ml of hypophosphorous acid solution and 0.1g of CuCl into a 500ml three-neck flask, stir, heat up to 40-45°C, add the reacted diazonium solution dropwise, after the dro...

Embodiment 2

[0041] In a 500ml three-necked flask, add 14.7g (0.1mol) of 2,3,4-trifluoroaniline, 100ml of the aqueous phase collected in Example 1, and control the temperature below 10°C, add dropwise 19.2g (1.2mol) of bromine, After the dropwise addition is completed, keep warm for 1 hour, let stand and separate layers to obtain an organic oil layer and a water layer. The organic oil layer is the crude product of 2,3,4-trifluoro-6-bromoaniline, which will enter the next step of reaction; the water layer will be recycled after being collected. .

[0042] Add the crude product of 2,3,4-trifluoro-6-bromoaniline obtained from the above reaction into a 500ml three-necked flask, and add 40ml of 98% concentrated sulfuric acid dropwise under stirring. Add 28ml of sodium nitrite solution with a fraction of 30%. After the dropwise addition, keep it warm for 1 hour and set aside.

[0043] Add 100ml of hypophosphorous acid solution and 0.1g of CuCl into a 500ml three-neck flask, stir, raise the temp...

Embodiment 3

[0046] In a 500ml three-neck flask, add 14.7g (0.1mol) of 2,3,4-trifluoroaniline and 100ml of dichloromethane, and control the temperature below 10°C, add 19.2g (0.12mol) of bromine dropwise, after the dropwise addition is complete, keep the temperature 1h, then add sodium sulfite aqueous solution to neutralize excess bromine and hydrogen bromide, extract twice with dichloromethane, evaporate dichloromethane to dryness to get 2,3,4-trifluoro-6-bromoaniline crude product, set aside .

[0047]Add the crude product of 2,3,4-trifluoro-6-bromoaniline obtained from the above reaction into a 500ml three-necked flask, and add 40ml of 98% concentrated sulfuric acid dropwise under stirring. Add 28ml of sodium nitrite solution with a fraction of 30%. After the dropwise addition, keep it warm for 1 hour and set aside.

[0048] Add 100ml of hypophosphorous acid solution and 0.1g of CuCl into a 500ml three-neck flask, stir, heat up to 40-45°C, add the reacted diazonium solution dropwise, a...

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 3, 4, 5-trifluoro bromobenzene. The method comprises the following steps: (1) dispersing 2, 3, 4-trifluoro aniline in a solvent, dropwise adding bromine to carry out a bromination reaction, thus obtaining 2, 3, 4-trifluoro-6-bromaniline through aftertreatment after the reaction is completed; (2) dissolving sodium nitrite in sulfuric acid, dropwise adding the 2, 3, 4-trifluoro-6-bromaniline obtained in the step (1) while stirring to carry out a diazotization reaction, thus obtaining a diazonium salt intermediate; and (3) under the action of hypophosphorous acid and a copper catalyst, carrying out a desamination reaction on the diazonium salt intermediate obtained in the step (2), thus obtaining the 3, 4, 5-trifluoro bromobenzene through aftertreatment after the reaction is completed. The preparation method has the advantages that the 2, 3, 4-trifluoro aniline is adopted as a starting material; the bromination reaction is realized with high selectivity; by-products are reduced; the purity and the yield of the brominated product are increased; the final yield and purity of the 3, 4, 5-trifluoro bromobenzene are high.

Description

technical field [0001] The invention belongs to the field of preparation of medicine and pesticide intermediates, in particular to a preparation method of 3,4,5-trifluorobromobenzene. Background technique [0002] 3,4,5-Trifluorobromobenzene, CAS number: 138526-69-9, the structure shown in formula (I), is an important chemical intermediate, widely used in the field of pesticides and medicine, 3, The carbon-bromine bonds contained in 4,5-trifluorobromobenzene can be prepared into Grignard reagents to achieve various functionalizations, and further used to synthesize various polyfluorinated active compounds. [0003] [0004] WO2013041497A1 discloses a method of using 3,4,5-trifluorobromobenzene as a raw material to synthesize a cathepsin C inhibitor. In this method, 3,4,5-trifluorobromobenzene is first converted into a boron reagent, and then combined with The halogenated aromatic substrate undergoes a coupling reaction to obtain a coupled product. [0005] Dhayalan, peo...

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): C07C25/13C07C17/35
Inventor 尹新易苗
Owner ZHEJIANG LINJIANG CHEM
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