- One-pot multistep synthetic strategies for the production of fenpropimorph using an ionic liquid solvent
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The one-pot synthesis of the fungicide fenpropimorph has been achieved using two different synthetic strategies in an ionic liquid. The first pathway consists of a Heck coupling followed by reductive animation; the second pathway consists of an aldol condensation followed by hydrogenation/reductive animation. Homogeneous and heterogeneous palladium catalysts have been utilised in the ionic liquid to provide a catalyst/solvent system that is suitable for recycling and process optimisation.
- Forsyth, Stewart A.,Gunaratne, H. Q. Nimal,Hardacre, Christopher,McKeown, Angela,Rooney, David W.
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- A methylphenylacrolein intermediates of the synthesis process (by machine translation)
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The invention discloses a method for preventing and method for synthesizing intermediate. The current in the synthetic method, some large erosion to the equipment, some three waste is high, some need to waste a great deal of alkali, the synthesis efficiency is low, unfavorable to industrialization. The invention relates to a para-tertiary-butyl-benzene formaldehyde and propionaldehyde as raw materials, polyol as a solvent, the metal hydroxide as condensing agent Aldol condensation reaction carried out, preventing and intermediate. This invention adopts the polyol (OH)- M x catalytic condensation system not only greatly improves the methylphenylacrolein synthesis of intermediates yield, and the condensation of the catalytic system can be recycled many times. These useful effect not only reduces the cost but also reduce the environmental pollution. (by machine translation)
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Paragraph 0021-0024; 0025-0030; 0031; 0032; 0033-0035
(2018/09/08)
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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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- Pd/Al2O3-catalysed redox isomerisation of allyl alcohol: Application in aldol condensation and oxidative heterocyclization reactions
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The application of the Pd/Al2O3 catalyst in allyl alcohol isomerization and subsequent aldol condensation and heterocyclization reactions is described. The activity of Pd/Al2O3 in these transformations is suggested to be due to the participation of the Lewis acidic sites of the support in the activation of the alcohol towards oxidative dehydrogenation by the metal and subsequent hydride transfer. The resulting enol(ate)/aldehyde could undergo further reactions promoted by the acid-base properties of the support. In the aldol condensation reactions of the isomerization product, electron poor aromatic aldehydes and heteroaromatic aldehydes showed the highest activity, while aromatic aldehydes bearing electron donating substituents reacted after transformation to the corresponding N-tosyl imines. 1,2-Disubstituted aromatics gave heterocyclic products in one-pot multistep reaction sequences.
- Zsolnai, Dániel,Mayer, Péter,Szori, Kornél,London, Gábor
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p. 3814 - 3820
(2016/06/13)
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- CONTINUOUS METHOD FOR PRODUCTION OF CINNAMALDEHYDE AND DIHYDROCINNAMALDEHYDE DERIVATIVES
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The present invention relates to a continuous process for the preparation of cinnamaldehyde or cinnamaldehyde derivatives by continuous reaction of benzaldehyde derivatives with alkanals in the presence of bases and optionally subsequent continuous hydrogenation in a circulation reactor in the presence of a suspension catalyst and hydrogen to give dihydrocinnamaldehyde derivatives.
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Page/Page column 7-8
(2008/06/13)
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- Process for the preparation of dihydrocinnamaldehyde derivatives
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There is disclosed a novel process for preparing a number of cinnamaldehyde derivatives. These cinnamaldehyde derivatives can be reduced to dihydrocinnamaldehyde derivatives, a number of which are commercially important in the preparation of fragrances. The invention is also directed to a number of novel intermediates and their preparation.
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