- Synthesis method of cinnamyl aldehyde compound
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The invention discloses a synthesis method of a cinnamyl aldehyde compound. The cinnamyl aldehyde compound is synthesized through the crossed dehydrogenation coupling reaction with fatty aldehyde andsbstituted sromatic hydrocarbon as the initial raw materials and palladium chloride and amino acid as the catalysts. Compared with a traditional cinnamyl aldehyde compound synthesis method, the methodis simple in operation, mild in reaction condition, low in applied reagent price, high in efficiency and high in atom utilization rate.
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Paragraph 0014; 0015
(2019/06/07)
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- A synthetic route to 4-alkyl-α-methylhydrocinnamylaldehydes
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The 4-Alkyl-α-methylhydrocinnamylaldehydes (alkyl-isopropyl, isobutyl, methyl) are frequently used fragrances with desired floral (lilac, cyclamen, lily-of-the-valley) scent. These substances are valued for their good stability in basic solution and, therefore, are frequently used in soaps, detergents, or shampoos. These substances are synthesized by a two-step synthesis involving base catalyzed aldol condensation of 4-alkylbenzaldehyde with propanal followed by selective hydrogenation of the C=C bond. In aldol condensation, selectivity is decreased by formation of undesired products of propanal autocondensation 2-methylpent-2-enal. In this work the reaction conditions for homogenous catalyzed aldol condensation of 4-isobutylbenzadehyde with propanal were tested (catalyst type and amount, molar ratio of reactants, solvent type). Reaction conditions giving the best results (92% conversion, 79% selectivity) were adapted to other 4-alkyl-α-methylcinnamylaldehydes preparation with similar results. In the second step—hydrogenation of aldol product different types of catalyst (nickel, cobalt, palladium or Adkins catalyst), and also different solvents, were tested. Hydrogenation conditions leading to the highest yield (72% selectivity at 95% conversion) were adapted to other 4-alkylhydrocinnamyladehydes with similar results.
- Vrbková, Eva,Vysko?ilová, Eli?ka,Rott, Martin,Zapletal, Martin,?erveny, Libor
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p. 2603 - 2613
(2017/03/22)
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- Cyclamen aldehyde synthesis: Aldol condensation followed by hydrogenation over ruthenium catalyst
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Cyclamen aldehyde is a fragrant substance with the scent of cyclamen or lily-of-the-valley. In this work, the desired cyclamen aldehyde was prepared by twostep synthesis. At the first step, aldol condensation of 4-isopropylbenzaldehyde and propanal was carried out. The influence of used catalyst (potassium hydroxide and sodium methoxide) and propanal amount were tested. Propanal was used in excess and it was added to the reaction mixture dropwise (to prevent its self-condensation to 2-methylpent-2-enal). Resulting mixture of 4-isopropylbenzaldehyde and forcyclamen aldehyde was hydrogenated using different Ru/C catalysts. The products detected in hydrogenation reaction mixture were: desired cyclamen aldehyde, cyclamen alcohol and forcyclamen alcohol. The influence of catalyst type and amount, reaction temperature and hydrogen pressure on the reaction course was tested. The highest yield (19.4 %) was obtained using pressure 10 MPa, temperature 110 °C and 2 wt% of catalyst Ru/C.
- Vrbkov, Eva,Skpala, Tom,Vyskoilov, Elika,erven, Libor
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p. 9195 - 9205
(2015/03/04)
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- Microwave-assisted organocatalytic cross-aldol condensation of aldehydes
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An environmentally benign organocatalytic cross-aldol condensation of aldehydes under microwave irradiation in the absence of solvent is described. Using pyrrolidine as a catalyst, an efficient and sustainable atom economic method was developed for the cross-aldol condensation of various aldehydes with excellent results. Among the products, jasmine aldehyde, α-hexyl cinnamaldehyde and cyclamen aldehyde, three compounds of great industrial demand, were synthesised.
- Limnios, Dimitris,Kokotos, Christoforos G.
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p. 4496 - 4499
(2013/05/09)
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