A kind of synthetic method of 3-methyl-2-butene-1-aldehyde diisopentenyl acetal

An aldehyde diprenyl acetal, synthesis method technology, applied in chemical instruments and methods, preparation of organic compounds, organic compounds/hydrides/coordination complex catalysts, etc., can solve the complex and difficult post-processing process. The problems of industrialized large-scale production and difficult control of usage amount can improve the activity and product selectivity, which is beneficial to industrialized large-scale production and has significant environmental protection benefits.

Active Publication Date: 2022-04-12
SHANDONG NHU PHARMA
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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
[0008] Patent US5177265A discloses that prenyl aldehyde and prenol are used as raw materials, phosphoric acid is used as a catalyst for condensation reaction, and toluene is added as a solvent to form an azeotrope with water. The reaction temperature is 60-90°C and the pressure is 8000-14000Pa (absolute pressure), the conversion rate of prenaldehyde is 83%, and the yield of acetal is 75.6%. Neutralize wastes, etc., increasing the "three wastes", the post-treatment process is complicated, and it is difficult to realize industrialized mass 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
Its disadvantages are: using isopentonic acid as a catalyst, prone to side reactions, difficult to recycle and apply mechanically, and unfavorable for industrial production
The three-step reaction is completed in the same reactor, resulting in low conversion rate of raw materials, complex products and difficult separation
[0013] In summary, using inorganic acid or organic acid as a catalyst to catalyze the aldol condensation reaction of prenaldehyde and prenol to prepare 3-methyl-2-butene-1-aldehyde diprenyl acetal, Side reactions are prone to occur, catalysts are not easy to recycle and apply, and are corrosive to equipment, which not only increases production costs, but is also unfriendly to the environment

Method used

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  • A kind of synthetic method of 3-methyl-2-butene-1-aldehyde diisopentenyl acetal
  • A kind of synthetic method of 3-methyl-2-butene-1-aldehyde diisopentenyl acetal
  • A kind of synthetic method of 3-methyl-2-butene-1-aldehyde diisopentenyl acetal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Place a certain amount of HZIF-8 material in a vacuum oven at 80°C and dry for 10 hours to remove all the moisture in the carrier until the carrier is completely dry. Accurately weigh 10 g of the dried carrier, add it into 50 g of toluene, disperse evenly, heat to 80°C, keep warm for 12 hours, filter, wash, and vacuum dry at 70°C until constant weight. At 70°C, evenly disperse the pretreated carrier into 100g PEG400, stir at a constant speed, and after 2 hours of heat preservation, add 0.9g (R)-CPA (the two groups R are both 4-F 3 CC 6 h 4 ), raise the temperature to 80°C, keep warm for 4 hours, cool to room temperature, filter, and dry to constant weight at 80°C to obtain the catalyst, marked as 9.0 wt.% 4-F 3 CC 6 h 4 -(R)-CPA / HZIF-8 (the loading here is the loading relative to the dry carrier mass).

[0049] Using the same method as above, change the configuration of chiral phosphoric acid and the type of R group, the type and ratio of carrier and surface modifi...

Embodiment 27

[0061] Example 27 Catalyst application

[0062] For catalyst 9.0 wt.% 4-F 3 CC 6 h 4 -(R)-CPA / HZIF-8 Carried out the experiment of catalyst application to investigate the stability of the catalyst. 9.0 wt.% 4-F in Example 14 3 CC 6 h 4 -The catalyst of (R)-CPA / HZIF-8 is used to catalyze the synthesis of 3-methyl-2-butene-1-aldehyde diisopentenyl acetal according to the method of the above-mentioned catalyst performance test, after 3000 hours of continuous use , when the catalyst activity is lower than 70%, regenerate and activate the catalyst, and then continue to apply it. The specific operation is the same as that in the catalyst performance test. The specific experimental data are shown in Table 3.

[0063] The regeneration and activation method of the catalyst is as follows: uniformly disperse the catalyst in a mixed solvent of toluene and ethanol, stir at 80°C for 5 hours, filter, and vacuum-dry at 80°C until constant weight.

[0064] Table 3 Application data

[...

Embodiment 28

[0068] Example 28 using 9.0 wt.% 4-F 3 CC 6 h 4 -(R)-CPA / HZIF-8 as a catalyst for the reaction

[0069] In a glass beaker, mix prenaldehyde and prenol at a molar ratio of 1:2, add 9.0 wt.% 4-F 3 CC 6 h 4 -(R)-CPA / HZIF-8 3.0wt.% (accounting for the total amount of prenol and prenal) as a catalyst, after mixing evenly, set aside.

[0070] Add the mixed liquid into a 500ml stainless steel reaction kettle, replace with nitrogen 3 times, start stirring and heating, the stirring speed is 400 rpm, the temperature is set at 80°C, and the reaction is kept at normal pressure for 2 hours. The reaction solution was detected by gas chromatography, and the conversion and selectivity were calculated. The results are: the conversion rate of prenaldehyde is 98.75%, the selectivity of 3-methyl-2-butene-1-aldehyde diprenyl acetal is 99.26%, and the selectivity of 3-methyl-2-butene- The crude product yield of 1-aldehyde di-isopentenyl acetal is 98.02%.

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Abstract

The invention provides a synthesis method of 3-methyl-2-butene-1-aldehyde diprenyl acetal, in the presence of a supported catalyst, prenyl aldehyde and prenol undergo aldol condensation Synthesis of 3-methyl-2-butene-1-aldehyde di-isopentenyl acetal with high reaction activity and high selectivity. The catalyst of the present invention improves the activity of reactants and the selectivity of products, can obtain higher yields, avoids the problem of equipment corrosion, prolongs the service life of equipment, has remarkable environmental protection benefits, is environmentally friendly, and is beneficial to large-scale industrial production .

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a synthesis method of 3-methyl-2-butene-1-aldehyde di-isopentenyl acetal. Background technique [0002] 3-methyl-2-butene-1-aldiprenyl acetal, an intermediate in the production process of citral, is obtained by condensation of prenyl aldehyde and prenyl alcohol, and then cracked to obtain citral precursor, and then rearranged to give citral. [0003] Citral (also known as 3,7-dimethyl-2,6-octadiene-1-al), present in 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 are subjected to three steps of condensation, thermal cracking and rearrangement to obtain citral. Prenyl alcohol and prenyl al...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C41/56C07C43/303B01J31/06B01J31/02
CPCC07C41/56B01J31/0258B01J31/068B01J31/0269C07C43/303
Inventor 马慧娟马啸籍晓飞黄珊珊于明宦关生姜晓阳范玉雪
Owner SHANDONG NHU PHARMA
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