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Preparation method for 4-acetoxyl-2-methyl-2-butenal

A technology of acetoxy and butenal, which is applied in the field of preparation of 4-acetoxy-2-methyl-2-butenal, can solve the problems of low yield, high price and the like, achieves high yield, The effect of high total yield and cheap and easy-to-obtain catalysts

Active Publication Date: 2015-06-17
SHANGYU NHU BIOCHEM IND +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main problem of this method is: the acylation process of a tertiary alcohol by compound 2 to 3, because the hydroxyl group of the tertiary alcohol is hindered greatly, so the yield is low
However, this method requires the use of expensive rhodium catalysts

Method used

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  • Preparation method for 4-acetoxyl-2-methyl-2-butenal
  • Preparation method for 4-acetoxyl-2-methyl-2-butenal
  • Preparation method for 4-acetoxyl-2-methyl-2-butenal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] (1) Preparation of aldols

[0043] At 0°C, dissolve 44g of ethylene oxide in 100ml of toluene to prepare an ethylene oxide toluene solution and store it at low temperature. Add 56g of acrolein in the reaction flask, and dissolve it with an appropriate amount of toluene, add 76g of trimethylphosphine to the reaction flask while stirring, and after 0.5h, add the prepared ethylene oxide toluene solution dropwise to the reaction system, 40± The reaction was terminated after continuous stirring at 5°C for 24 h. The solvent toluene was distilled off under normal pressure, and then 87 g of a colorless liquid product enaldol was distilled out under reduced pressure, with a content of 97.5% and a yield of 85%.

[0044] (2) Preparation of aldol esters

[0045] Add 100g of acetic anhydride to the reaction flask, and add 5g of ion-exchange resin loaded with periodic acid at room temperature (the ion-exchange resin used is Amberlyst15, soaked in 0.1M periodic acid solution for 12 ...

Embodiment 2

[0049] (1) Preparation of aldols

[0050] At 0°C, 44g of ethylene oxide was dissolved in p-xylene to prepare an ethylene oxide toluene solution and stored at low temperature. Add 56g of acrolein in the reaction flask, and dissolve it with an appropriate amount of p-xylene, add 76g of trimethylphosphorus to the reaction flask while stirring, and after 0.5h, add the prepared ethylene oxide toluene solution dropwise to the reaction system, After continuous stirring for 24 h, the reaction was terminated. The solvent toluene was distilled off under normal pressure, and then 82 g of the product enaldol in the form of a colorless liquid was distilled out under reduced pressure, with a content of 97.1% and a yield of 79.8%.

[0051] (2) Preparation of aldol esters

[0052] Add 94g acetic anhydride in reaction flask, add the ion-exchange resin of 4.7g loading periodate at normal temperature (the ion-exchange resin used is Amberlyst15, soak 12 hours with the periodate solution of 0.1M...

Embodiment 3

[0056] (1) Preparation of aldols

[0057] At 0°C, 44g of ethylene oxide was dissolved in toluene to prepare an ethylene oxide toluene solution and stored at low temperature. Add 56g of acrolein into the reaction flask, dissolve it with an appropriate amount of toluene, add 250g of triphenylphosphine to the reaction flask while stirring, and after 0.5h, add the prepared ethylene oxide toluene solution dropwise to the reaction system, and continue stirring After 24 h the reaction was complete. The solvent toluene was evaporated under normal pressure, and then 65 g of the colorless liquid product alkenyl alcohol was evaporated under reduced pressure, with a content of 95% and a yield of 62%.

[0058] (2) Preparation of aldol esters

[0059] Add 75g of acetic anhydride to the reaction flask, and add 4g of ion-exchange resin loaded with periodic acid at room temperature (the ion-exchange resin used is Amberlyst15, soaked in 0.1M periodic acid solution for 12 hours, obtained after...

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Abstract

The invention discloses a preparation method for 4-acetoxyl-2-methyl-2-butenal. The method comprises the following steps that (1) in organic solvent, under the action of phosphine reagents, ethylene oxide and acraldehyde carry out a Morita-Baylis-Hillman reaction, and olefine aldehyde alcohol is obtained; (2) the olefine aldehyde alcohol obtained in the step (1) and an acetylation reagent carry out an acylation reaction, and olefine aldehyde alcohol ester is obtained; (3) under the action of double bond transposition catalysts and hydrogen, the olefine aldehyde alcohol ester obtained in the step (2) carries out a double bond transposition reaction, and the 4-acetoxyl-2-methyl-2-butenal is obtained. According to the preparation method, the ethylene oxide and the acraldehyde serve as raw materials to carry out three steps of reactions to obtain five-carbon aldehyde, the raw materials are common chemical raw materials, low in price, easy to obtain and low in cost, operation is simple, atom economy is extremely high, the three wastes are not produced, and the preparation method is an effective synthetic route.

Description

technical field [0001] The invention belongs to the field of preparation of chemical intermediates, and in particular relates to a preparation method of 4-acetoxy-2-methyl-2-butenal. Background technique [0002] 4-Acetoxy-2-methyl-2-butenal, referred to as five-carbon aldehyde, is a key intermediate for the synthesis of vitamin A. The current synthesis methods mainly include dimethoxy Propyl acetone method, ethylene oxide method, isoprene method and butylene glycol method, etc. [0003] [0004] U.S. Patent No. 5,453,547 discloses a dimethoxyacetone method for preparing pentacarbon aldehyde. Taking dimethoxyacetone 1 as raw material, reacts with acetylene and hydrogen to generate compound 2, then reacts with acetic anhydride to obtain corresponding compound 3, and then Under the action of Cu-based catalyst, the double bond isomerized to obtain compound 4, and finally hydrolyzed to obtain five-carbon aldehyde. The main problem of this method is: the acylation process of...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/145C07C67/293
Inventor 田金金甄剑飞曾县明单国红管敏虾
Owner SHANGYU NHU BIOCHEM IND