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Method for catalyzing Claisen rearrangement at lower temperature

A rearrangement and catalyst technology, applied in the field of catalysis, can solve problems such as high pressure, high energy consumption, and low product quality, and achieve the effects of reducing rearrangement reaction temperature, reducing production energy consumption, and low equipment requirements

Pending Publication Date: 2022-03-01
SHANXI WEIQIDA PHARMA IND +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The reaction equipment requires high requirements and consumes a lot of energy, and the yield reported in the patent is about 90%, indicating that about 10% of high-polymer waste is generated; the content of isomers is not disclosed in the patent
[0009] In view of the problems of high temperature, high pressure, and low product quality in the Claisen rearrangement method in the prior art, it is urgent to find a method for catalytic Claisen rearrangement with low temperature and high product quality.

Method used

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  • Method for catalyzing Claisen rearrangement at lower temperature
  • Method for catalyzing Claisen rearrangement at lower temperature
  • Method for catalyzing Claisen rearrangement at lower temperature

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] With cis / trans-isopentenyl-3-methylbutadiene ether 152.24g (1.0mol) and the catalyst shown in the following formula:

[0031]

[0032] That is, 2-ethoxy-1,3-dimethyl-2,3-dihydro-1H-benzo[d][1,3,2]diazaphosphole105.1mg (0.5mmol) (relative to raw material cis / trans-isopentenyl -3-Methylbutadiene ether (0.05mol%) was added into the tank reactor, and then the reactor was replaced with nitrogen three times. After the replacement, the stirring was started and the temperature was raised to about 80°C. , the remaining raw materials are detected by GC <3%; open three sets of decompression pumps, and slowly increase the temperature to 110°C, at this time, the pressure in the kettle is about 400Pa, keep the temperature in the kettle at 110-120°C and distill under reduced pressure until no liquid drops flow out . Collect the distillate to get 3,3-dimethyl-2-isopropenyl-4-pentene-1-aldehyde (isomer) and 3,7-dimethyl-2,6-octadienal (lemon Aldehyde) mixture 139.9 g, yield 90%, GC...

Embodiment 2

[0036] With 1522.4g toluene, cis / trans-isopentenyl-3-methylbutadiene ether 152.24g (1.0mol), the catalyst shown in the following formula:

[0037]

[0038] That is, 2,5,6-trimethoxy-1,3-dimethyl-2,3-dihydro-1H-benzo[d][1,3,2]diazaphosphole1281.25mg (5mmol) (relative to raw material cis / trans-iso Pentenyl-3-methylbutadiene ether (0.5mol%) was added into the tank reactor, and then the reactor was replaced with nitrogen three times. After the replacement, the stirring was started and the temperature was raised to about 120°C. After reacting for 60 minutes, no residual raw materials were detected by GC; first, a group of decompression pumps were turned on, and the pressure in the kettle was reduced to 1500pa to distill out the low boiling point solvent p-xylene, and the temperature was kept at 50-80°C; the pressure was reduced until there was no liquid drop After flowing out, turn on three sets of decompression pumps, and slowly raise the temperature to 110°C at the same time. ...

Embodiment 3

[0042] With 1091g xylene, 8-(1-(allyloxy)vinyl)spiro[4.5]dec-7-ene 218.34g (1mol), the catalyst shown in the following formula:

[0043]

[0044]That is, 2,5,6-triethoxy-1,3-dimethyl-2,3-dihydro-1H-benzo[d][1,3,2]diazaphosphole298.32mg (1mmol), was added to the tank reactor followed by The reaction kettle was replaced with nitrogen three times. After the replacement, the stirring was started, and the temperature was raised to about 70°C. After 5 hours of reaction, no residue of raw materials was detected by GC. First turn on a group of decompression pumps, reduce the pressure in the kettle to 1500pa to distill out the low boiling point solvent xylene, and depressurize until no liquid drops flow out; turn on three sets of decompression pumps, and slowly increase the temperature to 130°C at the same time. The pressure in the kettle is about 300Pa, and the temperature in the kettle is kept at 130°C for vacuum distillation until no liquid drops flow out. The distillate was col...

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Abstract

The invention provides a method for catalyzing Claisen rearrangement at a relatively low temperature, and relates to the field of catalysis, and the method uses a catalyst DAPs to catalyze allyl ether of enol to obtain a Claisen rearrangement product through rearrangement. According to the reaction, the production energy consumption can be reduced, the operation can be simplified, and meanwhile the requirement for equipment is low.

Description

technical field [0001] The invention relates to the field of catalysis, in particular to a method for catalyzing Claisen rearrangement at a relatively low temperature. Background technique [0002] When the allyl ether of enol is heated to 200°C, intramolecular rearrangement occurs, and the allyl group moves from the oxygen atom to the carbon atom, also known as Claisen rearrangement. The Claisen rearrangement was originally discovered in aromatic compounds, and later found that the reaction can be extended to non-aromatic compounds. The rearrangement of non-aromatic allyl vinyl ethers, because there is no enolization driving force, stays at The carbonyl stage, known as an aliphatic Claisen rearrangement. Therefore, providing synthetically useful intermediates has become an important synthetic method for industrial products, medicine and pesticides, etc. Therefore, most of the current Claisen rearrangement reactions require the presence of high boiling point solvents such ...

Claims

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Application Information

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IPC IPC(8): C07C45/51C07C45/67C07C47/21C07C49/557
CPCC07C45/513C07C45/67C07C2602/50C07C47/21C07C49/557
Inventor 田虎管文成张建强幸华龙王世珍田湘寅刘国杰王鹏
Owner SHANXI WEIQIDA PHARMA IND
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