Composite catalyst, preparation method thereof and application thereof in citral synthesis

A composite catalyst, citral technology, applied in the preparation of carbon-based compounds, chemical instruments and methods, organic compounds/hydrides/coordination complex catalysts, etc. The problem of high reaction temperature can reduce the formation of high boiling point substances, improve the space effect, and simplify the preparation process.

Pending Publication Date: 2020-12-11
SHANDONG NHU PHARMA
View PDF17 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its disadvantages are: the catalyst is an acid with a low boiling point, the amount of use is not easy to control, it is difficult to recycle and apply mechanically, the requirements for production equipment are high, and there is a hidden danger of environmental pollution
When the reaction substrate is prenol and prenal, the conversion rate of prenal is greater than 97%, and its disadvantage is that the amount of nitric acid is difficult to control
[0007] U.S. Patent No. 5,177,265A discloses prenyl aldehyde and prenol as raw materials, phosphoric acid as a catalyst for condensation reaction, adding toluene as a solvent, wherein toluene can form an azeotrope with water, the reaction temperature is 60-90 ° C, the pressure It is 8000-14000Pa (absolute pressure), the conversion rate of prenaldehyde is 83%, and the yield of acetal is 75.6%, and its shortcoming is: unnecessary acid needs to pass through potassium acetate, sodium acetate, carbonic acid Neutralization with salt or hydroxide, etc., increases the "three wastes", the post-treatment process is complicated, and it is difficult to realize industrialized large-scale production
The disadvantages of this patent are: 1. 3-methyl-2-butene-1-aldehyde di-isopentenyl acetal is used in a large amount; 2. The amount of phosphoric acid is small, the control is difficult, and it is difficult to carry out continuous production
Its disadvantages are: the lithium chloride used is highly corrosive and the reaction is carried out under negative pressure conditions, which is not convenient for continuous production and energy saving
The disadvantages are: under high temperature conditions, protonic acids such as phosphoric acid are used as catalysts, which is

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Composite catalyst, preparation method thereof and application thereof in citral synthesis
  • Composite catalyst, preparation method thereof and application thereof in citral synthesis
  • Composite catalyst, preparation method thereof and application thereof in citral synthesis

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0071] Example 1

[0072] At room temperature, place 50 g of dried HMAS-5 molecular sieves in a three-necked flask, add 300 mL of toluene to swell for 12 hours, add 80 mL of thionyl chloride, react at 70°C for 10 hours, filter, wash, and vacuum dry at room temperature to constant temperature. Heavy. The swollen carrier was dispersed in 300 mL of toluene, 1250 g of PEG 400 was added, and after refluxing for 8 hours, suction filtration, washing, air drying, and vacuum drying at room temperature to constant weight. The above carrier was then dispersed in 300 mL of toluene, 95.39 g of ethanolamine (25:1) was added, the reaction was refluxed for 6 hours, filtered with suction, washed, and dried under vacuum at room temperature to constant weight. Swell with 300mL toluene and ethanol mixed solvent (volume ratio 1:1) for 10 hours, add 10.14g ferric chloride, 132.0g (MW.263.89) dodecyl trimethyl ammonium chloride, reflux for 24 hours, suction filtration , washed, air-dried, and vacu...

Example Embodiment

[0079] Example 21-80 Catalyst performance test example

[0080] The catalyst performance test is carried out as follows:

[0081]Mix prenaldehyde and prenol in a liquid storage tank according to a certain molar ratio (1:2.0), and when the temperature of the catalyst bed in the reactor reaches 70-120 °C, the reaction is carried out continuously to the fixed bed through an orifice flowmeter. The feed rate is 1.67-16.7mL / min, the residence time is 0.1-1.0 hours, the reaction occurs in the catalyst bed, and the unreacted prenol takes water out of the fixed bed, and is separated by an oil-water separator. , the unreacted prenol enters the liquid storage tank, and the water produced by the reaction is discharged as waste water; the product is discharged from the bottom of the reactor, and after the produced liquid is analyzed by gas chromatography, 3-methyl-2-butene-1- The content of the aldehyde diprenyl acetal is more than 98%, and it enters the cracking tower for cracking reacti...

Example Embodiment

[0097] Embodiment 81 Catalyst is applied mechanically

[0098] The above-mentioned No. 1 catalyst was selected to carry out the experiment of applying the catalyst mechanically. The catalysts used in Example 21, Example 41, and Example 61 were soaked for 10 hours under stirring conditions of 80°C, 100°C, and 120°C using toluene-ethanol mixed solvent (volume ratio 1:1), suction filtered, washed , air-dried, and vacuum-dried to constant weight at room temperature. The specific operation is the same as that in the catalyst performance test. The specific experimental data are shown in Table 5.

[0099] Table 5.1 Data applied to catalyst No. 1 in the aldol condensation reaction

[0100]

[0101]

[0102] Note: the aldol condensation reaction conditions are the same as those in Example 21; the conversion rate, selectivity and yield in the table are the same as the definitions for conversion rate, selectivity and yield in Example 21.

[0103] Table 5.2 Data applied to catal...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
The inside diameter ofaaaaaaaaaa
Lengthaaaaaaaaaa
Particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention discloses a composite catalyst, a preparation method thereof and an application of the composite catalyst in citral synthesis, the catalyst comprises a loading component and a carrier, and the loading component comprises an active component and other components; the active component is metal salt; the other components comprise a connecting arm R, a ligand L and a component B; in thepresence of the composite catalyst, isopentenal and isopentenol are subjected to alcohol-aldehyde condensation, thermal cracking and rearrangement reaction to synthesize citral with high activity andhigh selectivity, and the catalyst does not need to be replaced in the reaction process. The catalyst provided by the invention improves the selectivity of the product, can obtain higher yield, avoidsthe problem of equipment corrosion, prolongs the service life of the equipment, has obvious environmental protection benefits, is environment-friendly, and is beneficial to industrial mass production.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a method for synthesizing citral with a new catalyst, in particular to a method for synthesizing citral with prenyl alcohol and prenyl aldehyde as raw materials. Background technique [0002] Citral (also known as 3,7-dimethyl-2,6-octadiene-1-al), present in plant essential oils such as lemongrass oil and eucalyptus oil, has a strong lemon aroma. It is widely used in spices, medicine, daily chemical and food industries, and its acquisition is mainly through chemical synthesis. At present, the mainstream synthesis route in the industry is the C5+C5=C10 route, that is, two C5 raw materials, a total of three steps: the first step: prenol and prenyl aldehyde undergo aldol condensation to generate 3-methyl-2 -butene-1-aldehyde di-prenyl acetal; second step: 3-methyl-2-butene-1-aldehyde di-prenyl acetal pyrolysis to generate prenyl-3- Methyl-2-butenyl ether (citral precursor); the th...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B01J31/22B01J35/02C07C45/51C07C47/21
CPCB01J31/1805B01J35/026C07C45/513C07C41/18C07C41/01B01J2531/842C07C47/21C07C43/15Y02P20/584
Inventor 马啸马慧娟黄珊珊籍晓飞于明黄冬范玉雪张磊
Owner SHANDONG NHU PHARMA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap