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Preparation method of 3, 4, 5-trimethylhydroquinone dialkanoate

A technology of trimethylhydroquinone dialkanoate and diketone, which is applied in the field of preparation of 3,4,5-trimethylhydroquinone dialkanoate and can solve the problems of poor selectivity and low product yield, etc.

Active Publication Date: 2020-07-10
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In summary, it can be seen that the current method for preparing 3,4,5-trimethylhydroquinone dialkanoate has the problems of low product yield and poor selectivity , therefore need to seek a kind of preparation method of new 3,4,5-trimethylhydroquinone dialkanoate to solve the above-mentioned technical problems

Method used

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  • Preparation method of 3, 4, 5-trimethylhydroquinone dialkanoate
  • Preparation method of 3, 4, 5-trimethylhydroquinone dialkanoate
  • Preparation method of 3, 4, 5-trimethylhydroquinone dialkanoate

Examples

Experimental program
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Effect test

Embodiment 1

[0033] 40.0g acetic anhydride, 1.0g BF 3 ·OEt 2 Catalyst, 0.0700g 5-hydroxy-6-methylnicotinic acid was placed in a 250mL three-necked flask, mechanical stirring was started, and 20.0g 2,6,6-trimethylcyclohex-2-ene-1,4-di Ketone (99.5% purity, the same below) was slowly dropped into the three-necked flask. The mixture was reacted at a constant temperature of 60°C for 10 hours. After the reaction was completed, the reaction solution was taken for gas chromatography analysis. The conversion rate of the raw material 2,6,6-trimethylcyclohex-2-ene-1,4-dione was 99.3%. The selectivity of the product 3,4,5-trimethylhydroquinone diacetate is 81.4%.

[0034] Cool the reaction solution to -5°C, separate the solid and the solution in the system, add 100.0 g of petroleum ether (90-120) to the obtained solid at 75°C, dissolve it fully, let it stand and cool naturally to 20°C to crystallize, and Keep it standing at 20°C for 8h. The precipitated crystals were filtered, and the filter cake...

Embodiment 2

[0036] Put 38.85g of acetyl chloride, 397.0g of ethanol, 1.7g of phosphoric acid catalyst, and 0.05g of nicotinic acid furfurate into a 1000mL three-necked flask, turn on mechanical stirring, and mix 25.0g of 2,6,6-trimethylcyclohexyl-2- En-1,4-dione was slowly dropped into the three-necked flask. The mixture was reacted at a constant temperature of 80°C for 5 hours. After the reaction was completed, the reaction solution was taken for gas chromatography analysis. The conversion rate of the raw material 2,6,6-trimethylcyclohex-2-ene-1,4-dione was 98.1%. The selectivity of the product 3,4,5-trimethylhydroquinone diacetate is 85.9%.

[0037]Cool the reaction solution to -20°C, separate the solid and solution in the system, add 30.0 g of chlorobenzene and 100 g of ethyl acetate to the obtained solid at 75°C, dissolve it fully, let it stand and cool to 20°C to crystallize naturally, and Keep it standing at 20°C for 8h. The precipitated crystals were filtered, and the filter cake...

Embodiment 3

[0039] 61.1g propionyl chloride, 472.0g cyclohexane, 2.0g FeCl 3 Catalyst, 0.05g 5-hydroxy-6-methylnicotinic acid ethyl ester was placed in a 1000mL three-necked flask, mechanical stirring was started, and 25.0g 2,6,6-trimethylcyclohex-2-ene-1,4 - Slowly drop the diketone into the three-neck flask. The mixture was reacted at a constant temperature of 50°C for 8 hours. After the reaction was completed, the reaction solution was taken for gas chromatography analysis. The conversion rate of the raw material 2,6,6-trimethylcyclohex-2-ene-1,4-dione was 94.9%. The selectivity of the product 3,4,5-trimethylhydroquinone dipropionate is 87.3%.

[0040] Cool the reaction solution to -20°C, separate the solid and the solution in the system, add 20.0 g of ethyl acetate and 120 g of cyclohexane to the obtained solid at 75°C, dissolve it fully, let it stand and cool to 20°C for crystallization, And keep it standing at 20°C for 8h. The precipitated crystals were filtered, and the filter c...

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Abstract

The invention provides a preparation method of 3, 4, 5-trimethylhydroquinone dialkanoate. The preparation method comprises the following steps: reacting in the presence of a catalyst and a cocatalystand carrying out esterification and rearrangement reaction on 2, 6, 6-trimethylcyclohexyl-2-ene-1, 4-diketone and an acylating agent to obtain the product, wherein the catalyst is selected from sulfuric acid, hydrochloric acid, phosphoric acid, fluoroboric acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, chloroacetic acid, BF3, BF3.OEt2, AlCl3, FeCl3, ZnCl2, TiCl4, SnCl2 and the like, and the cocatalyst is selected from nicotinic acid, 3-pyridylaldehyde, phenyl nicotinate, furoate nicotinate, 5-hydroxy-6-methyl nicotinic acid and 5-hydroxy-6-methyl ethyl nicotinate. The process has the advantages of easiness in industrialization, good selectivity, high product yield and the like.

Description

technical field [0001] The invention relates to a preparation method of 3,4,5-trimethylhydroquinone dialkanoate. Background technique [0002] 3,4,5-trimethylhydroquinone dialkanoate and its hydrolyzed product 3,4,5-trimethylcatechol can be used as antioxidants for higher alcohols, higher fatty acids, and resins, and can also be used for It can be used to make spices and medicines, so its industrial application has broad prospects. [0003] US Pat. No. 3,624,134 discloses that α-isophorone reacts with an acylating agent in the presence of an acidic catalyst to obtain 3,5,6-trimethylcatechol diester with a yield of 20%. However, this method also produces a large number of by-products, whereby the yield of the target compound is very low. In addition, this compound cannot be isolated and purified in a simple manner. As for 3,4,5-trimethylhydroquinone dialkanoate, the document is silent. [0004] U.S. Patent No. 5,955,628A discloses that in the presence of an acid catalyst,...

Claims

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Application Information

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IPC IPC(8): C07C67/12C07C67/14C07C69/16C07C69/28
CPCC07C67/12C07C67/14C07C69/16C07C69/28Y02P20/584
Inventor 郭劲资黄真真张涛刘英瑞程晓波宋军伟张弈宇王嘉辉黎源
Owner WANHUA CHEM GRP CO LTD
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