Catalyst for preparing citral through dehydrolinalool rearrangement reaction, preparation method of catalyst and method for preparing citral

A technology for dehydrolinalool and rearrangement reactions, applied in metal/metal oxide/metal hydroxide catalysts, organic compound/hydride/coordination complex catalysts, chemical instruments and methods, etc., can solve the constraints Application, high post-treatment requirements, poor stability of citral, etc.

Active Publication Date: 2020-02-28
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process has mild reaction conditions, short reaction time, and easy operation, but the product citral has poor stability in this system and requires high post-treatment requirements, which largely limits the industrial application of this catalyst
[0009] In summary, it can be seen that the Meyer-Schuster rearrangement reaction is used to synthesize citral, and the vanadium-based catalysts, molybdenum-based catalysts, or titanium-based catalysts all have their own significant shortcomings, which restricts their industrial application.

Method used

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  • Catalyst for preparing citral through dehydrolinalool rearrangement reaction, preparation method of catalyst and method for preparing citral
  • Catalyst for preparing citral through dehydrolinalool rearrangement reaction, preparation method of catalyst and method for preparing citral
  • Catalyst for preparing citral through dehydrolinalool rearrangement reaction, preparation method of catalyst and method for preparing citral

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1~20 and comparative example 1-2

[0097] The spherical carrier is prepared by a method well known to those skilled in the art, and the specific process is as follows: after the carrier (for example, silicon dioxide, aluminum oxide and titanium dioxide) is ground into powder, it is added to water, stirred evenly to form a carrier slurry, and then shaped Granulation to produce spherical supports (for example, spherical silica, spherical alumina, and spherical titania). Roast at 500-1100°C for 4-6 hours before use to obtain a particle size range of 3-5mm and a BET specific surface area range of 50-150m 2 / g spherical carrier.

[0098] Adopt impregnation method to prepare solid acid catalyst, specific process is as follows: heteropolyacid (for example, silicotungstic acid, phosphomolybdic acid or phosphotungstic acid) and optional auxiliary agent (for example, gold trichloride, rhenium trichloride, Indium trichloride or lanthanum trichloride heptahydrate) was dissolved in water to form an impregnating liquid, and...

Embodiment 23~ Embodiment 50 and comparative example 3-4

[0105] Select 24 solid acid catalysts prepared in Examples 1-22 and Comparative Examples 1-2 to screen, the method is: investigate the catalyst reaction performance with a fixed-bed reactor from top to bottom, and the fixed-bed reactor has an internal diameter of 20 mm and a length of 800mm stainless steel pipe. The catalyst loading was 5g and diluted to 20ml with glass beads. The catalysts prepared in Examples 1-22 and Comparative Examples 1-2 were loaded into a fixed-bed reactor, and activated under nitrogen protection for 2 hours at 400°C. Then cool to below 40°C and stop nitrogen purging. After mixing dehydrolinalool and solvent according to a certain mass ratio, the liquid phase passes through the catalyst bed, and under the condition of continuously feeding nitrogen, the fixed bed reactor is adjusted to the temperature required for the reaction, and the nitrogen pressure is adjusted to maintain a suitable Reaction conditions, rearrangement of dehydrolinalool to prepare...

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Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a catalyst for preparing citral through dehydrolinalool rearrangement reaction, a preparation method of the catalyst and a method for preparing the citral. The catalyst is a solid acid catalyst and comprises an active component, a carrier and an optional assistant; wherein the active component is selected from one or more of silicotungstic acid, phosphomolybdic acid and phosphotungstic acid, and the assistant is selected from one or more of gold trichloride, rhenium trichloride, indium trichloride and lanthanum trichloride. The method for preparing the citral comprises the following step of: in the presence of a solvent and the solid acid catalyst, carrying out Meyer-Schuster rearrangement reaction by taking dehydrolinalool as a raw material to prepare the citral. The solid acid catalyst is simple to prepare, low in cost and long in service life; when the catalyst is used in the process of preparing citral, the reaction yield and the conversion rate are improved, and the selectivity is good; in addition, the catalyst is long in service life, and continuous large-scale operation can be realized.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a catalyst for preparing citral by dehydrolinalool rearrangement reaction, a preparation method thereof, and a method for preparing citral. Background technique [0002] Citral is a very important open-chain monoterpene spice with a strong lemon flavor. As one of the edible flavors stipulated in my country, it can be directly added to soft drinks, chewing gum, ice cream, candy and baked goods. It can also be used It is indispensable in the preparation of various fruit flavors, especially in citrus flavors. In addition, citral is also a very important intermediate in organic synthesis, which can be used to synthesize high-grade spices such as ionone and irone, as well as vitamin A, vitamin E, phytol, β-carotene, and isophytol. [0003] The natural citral can be extracted from the oil of Arboria chinensis through vacuum distillation, steam distillation, molecu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J31/18B01J31/16B01J23/30B01J27/135B01J27/19C07C45/51C07C47/21
CPCB01J27/188B01J23/30B01J27/135B01J27/19C07C45/512C07C47/21Y02P20/584
Inventor 沈稳黄文学于斌成谢硕张永振黎源
Owner WANHUA CHEM GRP CO LTD
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