Method for preparing 4-hexen-3-one by dehydration of 4-hydroxyl-3-hexanone

A technology of hexanone and hydroxyl, applied in the field of dehydration of 4-hydroxy-3-hexanone to prepare 4-hexen-3-one, which can solve the problems of low space velocity, poor catalyst activity and high reaction temperature

Active Publication Date: 2014-10-15
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is the problems of high reaction temperature, low space velocity and poor catalyst activity in the prior art

Method used

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  • Method for preparing 4-hexen-3-one by dehydration of 4-hydroxyl-3-hexanone
  • Method for preparing 4-hexen-3-one by dehydration of 4-hydroxyl-3-hexanone
  • Method for preparing 4-hexen-3-one by dehydration of 4-hydroxyl-3-hexanone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] By 1SiO 2 : 0.01Al 2 o 3 : 0.41TEAOH: 0.31 acetylacetone: 31.76H 2 O Weigh each material, dissolve sodium aluminate in distilled water, add tetraethylammonium hydroxide dropwise, stir for 1 hour, then add ethyl orthosilicate dropwise, stir for 1 hour, then add acetylacetone, stir for 1 hour , adjusted to pH = 13.0 with 0.1N sodium hydroxide solution, and continued to stir for 5 hours. The obtained mixture was crystallized under hydrothermal conditions at 170°C for 4 days, washed, filtered and dried. The obtained product had the characteristic diffraction peak of ZSM-5 and preferentially grew in the (010) direction (b axis). XRD spectrum see figure 2 In curve 1, the relative intensity of (020), (040), (060) and (080) peaks in the diffraction spectrum is significantly increased, which is obviously due to the preferred orientation of the ZSM-5 single crystal on the powder diffraction sample plate, and its (0h0) The surface, that is, the cylindrical surface of the sin...

Embodiment 2

[0023] By 1SiO 2 : 0.01Al 2 o 3 : 0.25TPAOH : 0.05 sodium oxalate : 32.0H 2 O Weigh each material, dissolve sodium aluminate in distilled water, add tetrapropylammonium hydroxide dropwise, stir for 1 hour, then add silica sol dropwise, stir for 1 hour, then add sodium oxalate, stir for 1 hour, use 0.1 N sodium hydroxide solution was used to adjust the pH to 12.0, and stirring was continued for another 5 hours. The resulting mixture was crystallized under hydrothermal conditions at 200°C for 3 days, washed, filtered and dried. XRD spectrum see figure 2 Middle curve 2. The synthesized raw ZSM-5 zeolite powder was treated with 0.8 mol / L acetic acid at 70°C for 5 hours for 4 consecutive times, wherein the weight ratio of the acid solution to the ZSM-5 zeolite was 9 to obtain HZSM-5, namely the catalyst.

[0024] The performance of catalyst is evaluated by each step of [Example 1]. Reaction conditions and reaction results are shown in Table 1.

Embodiment 3

[0026] By 1SiO 2: 0.02Al 2 o 3 : 0.23TEAOH: 0.278-hydroxyquinoline: 44.64H 2 O Weigh each material, dissolve aluminum triethoxide in distilled water, add tetraethylammonium hydroxide dropwise, stir for 1 hour, then add silica sol dropwise, stir for 1 hour, then add 8-hydroxyquinoline, stir for 1 hour , adjust pH=11.0 with 0.1N sodium hydroxide solution, and continue stirring for 5 hours. The resulting mixture was crystallized under hydrothermal conditions at 150°C for 6 days, washed, filtered and dried. XRD spectrum see figure 2 Middle curve 3. The synthesized ZSM-5 zeolite raw powder was treated with 0.8 mol / L acetic acid at 80°C for 5 hours for 3 consecutive times, wherein the weight ratio of the acid solution to the ZSM-5 zeolite was 8 to obtain HZSM-5, namely the catalyst.

[0027] The performance of catalyst is evaluated by each step of [Example 1]. Reaction conditions and reaction results are shown in Table 1.

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Abstract

The invention relates to a method for preparing 4-hexene-3-ketone by carrying out dehydration on 4-hydroxy-3-hexanone, mainly aiming at solving the problems of low catalyst activity, high reaction temperature and slow space velocity in the prior art. The catalyst used by the method is prepared by the following steps of: mixing a silicon source, an aluminium source, template agent R1, template agent R2 and water, and adjusting the pH of the reaction mixture to be 8-14 with inorganic base; in the reaction mixture, controlling the molar ratio between Al2O3 and SiO2 to be 0.003-0.05, controlling the molar ratio of R1 to SiO2 to be 0.1-2, controlling the molar ratio of H2O to SiO2 to be 10-100 and controlling the molar ratio of R2 to SiO2 to be 0.05-2; and carrying out hydrothermal crystallization on the mixture for 1-10 days at the temperature of 100-250 DEG C to obtain the catalyst, wherein R1 comprises at least one selected from tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropyl ammonium hydroxide or tetrabutyl ammonium hydroxide, and R2 comprises at least one selected from beta-diketone, beta-diketone salt, oxalic acid, oxalate, catechol or 8-hydroxyquinoline. The technical scheme better solves the problems, and can be used in the industrial production of the 4-hexene-3-ketone prepared by the 4-hydroxy-3-hexanone.

Description

technical field [0001] The invention relates to a method for preparing 4-hexen-3-one by dehydrating 4-hydroxyl-3-hexanone. Background technique [0002] 4-Hexen-3-one (CAS: 2497-21-4) is a unique spice (China GB 2760-2007), which is mainly used to prepare food flavors such as Laomu, butter, and horseradish, and has a wide range of uses. [0003] The dehydration reaction of hydroxyl compounds is a reaction in which the hydroxyl and hydrogen atoms on two adjacent atoms in the reactant molecule are removed in the form of water in the presence of a catalyst. Since the oxygen atom of the hydroxyl group contains a lone pair of electrons, it can interact with the proton (H + ) to form oxonium ions, which become strong electron-withdrawing groups due to the positive charges on the oxygen atoms, making the C-O bond easy to dissociate. The whole dehydration reaction includes: generating protonated oxonium salt (R-OH 2 + ), the oxonium salt slowly dissociates into a carbanion, and ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C49/203C07C45/66B01J29/40
Inventor 金照生李亚男黄祖娟
Owner CHINA PETROLEUM & CHEM CORP
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