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

A kind of synthetic method of 3,6-dihydro-2h-pyran-4-boronic acid pinacol ester

A technology of pinacol esters and synthesis methods, applied in the fields of compounds containing elements of group 3/13 of the periodic table, chemical instruments and methods, organic chemistry, etc., can solve flammable and explosive, high production costs, hidden safety hazards, etc. problem, achieve the effect of reducing production cost, simple synthesis method and simple process

Active Publication Date: 2016-04-06
CHEN STONE GUANGZHOU CO LTD
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This makes the production cost extremely high
And this method usually requires the use of ultra-low temperature and is not suitable for scale-up production
[0008] The second method uses dangerous butyllithium, which is flammable and explosive, and brings great safety hazards in production. It is not suitable for production scale-up, and butyllithium needs to use ultra-low temperature conditions, which greatly increases production costs.
[0009] Although these methods can all produce α-alkenylboronic acid pinacol esters, there are inevitable safety hazards in the scale-up production, or the production cost is too high

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
  • A kind of synthetic method of 3,6-dihydro-2h-pyran-4-boronic acid pinacol ester

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0029] A kind of synthetic method of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester, comprising steps:

[0030] 1) Tetrahydropyrone reacts with hydrazine hydrate in a solvent to form a monoketone hydrazone;

[0031] 2) Monoketone hydrazone and copper bromide react in a solvent in the presence of triethylamine to obtain a dibromo intermediate;

[0032] 3) The dibromo intermediate reacts with the base in a solvent to obtain an alkenyl bromide compound;

[0033] 4) In the presence of palladium complexes, alkenyl bromide compounds and biboronic acid pinacol esters undergo a Suzuki-Miyaura reaction in a solvent to obtain the product.

[0034] In step 1), the molar ratio of tetrahydropyrone to hydrazine hydrate is 1: (1-20); preferably, it is 1: (2-5).

[0035] In step 1), the solvent is dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, diphenyl ether, diethyl ether, methyl tert-butyl ether, ethylene glycol dimethyl ether, ethyl ether, One of glycol diethyl ...

Embodiment 1

[0047] Synthesis of tetrahydropyrone hydrazone

[0048] Under stirring, 5.0L of dichloromethane, 2.5kg of 80% hydrazine hydrate and 1.0kg of tetrahydropyrone were added dropwise to the reaction kettle at 20-30°C. After the dropwise addition was complete, stirring was continued at this temperature for 2 hours. 2.0 L of saturated brine was added, the layers were allowed to stand, and the organic phase was concentrated to obtain 830 g of tetrahydropyrone hydrazone, with a yield of 73%.

Embodiment 2

[0050] Synthesis of 4,4-Dibromotetrahydropyran

[0051] Under the protection of nitrogen and at room temperature, 5.0 L of methanol, 12.0 kg of copper bromide and 7.5 L of triethylamine were added to the reaction kettle. After the addition was complete, the stirring was continued at room temperature for half an hour. A methanol solution containing 1.0 kg of tetrahydropyrone hydrazone (the volume of the solution is 2 L) was added dropwise into the reaction kettle, and stirring was continued for half an hour at room temperature. Add 15L of ammonia water and 10L of ethyl acetate, let stand to separate layers, and concentrate the organic phase to obtain a crude product, which is decolorized by activated carbon to obtain 1.7kg of 4,4-dibromotetrahydropyran (purity greater than 95%), with a yield of 80%.

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 synthesis method of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester, comprising steps: 1) reacting tetrahydropyrone and hydrazine hydrate in a solvent to form monoketone hydrazone ; 2) The monoketone hydrazone and copper bromide react in a solvent in the presence of triethylamine to obtain a dibromo intermediate; 3) The dibromo intermediate reacts with a base in a solvent to obtain an alkenyl bromide compound; 4 ) In the presence of palladium complexes, Suzuki-Miyaura reaction between alkenyl bromide compound and biboronic acid pinacol ester in a solvent can give the product. The synthesis method of the invention is simple, low in cost, does not use dangerous raw materials, and can be safely scaled up for production.

Description

technical field [0001] The invention relates to a synthesis method of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester. Background technique [0002] In the prior art, there is no bibliographic report on the synthesis of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester. In general, the methods for synthesizing other types of α-alkenylboronic acid pinacol esters are as follows. [0003] Method 1 uses a ketone as a raw material to react with a trifluoromethanesulfonic acid compound to obtain an intermediate, and then reacts with biboronic acid pinacol ester to obtain the target product. [0004] [0005] The second method uses ketone as a raw material to react with p-toluenesulfonyl hydrazide to obtain an intermediate, and then reacts with butyl lithium and isopropyl borate pinacol ester to obtain the target product. [0006] . [0007] Method one involves the use of trifluoromethanesulfonic acid compounds, which are expensive. Four moles of trifluoromethanesulfonic...

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 Patents(China)
IPC IPC(8): C07F5/04
Inventor 郎丰睿戴洪果龙翔天陆永章王娟
Owner CHEN STONE GUANGZHOU 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