- Α, β - production of unsaturated aldehydes
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The present invention aims to provide a method for preparing an aldehyde, which can prepare a target aldehyde with high selectivity and can also suppress the production of by-products. The present invention relates to a method for preparing an α,β-unsaturated aldehyde. The method includes a step of reacting a compound of formula (I) with a compound of formula (II) to provide an α,β-unsaturated aldehyde of formula (III). An alkali metal hydroxide and an alkanol having 1 to 4 carbon atoms are used in the step. The amount of the alkali metal hydroxide is 8 mol% or more and 12 mol% or less with respect to the compound of formula (I). The total amount of water contained in materials that are used in the reaction is 10 mol% or more and 50 mol% or less with respect to the compound of formula (I).
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Paragraph 0083-0102
(2019/03/30)
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- Bifunctional organocatalysts for the synthesis of jasminaldehyde and their derivatives
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L-Proline in the presence of benzoic acid is found to be an effective catalytic system for the cross-aldol condensation of benzaldehyde with 1-heptanal under solvent free condition amongst the several amino acids screened for this reaction. Under the optimized reaction conditions, the desired product (e.g. jasminaldehyde) is formed up to 96% selectivity in one hour using the desired arylaldehyde: 1-alkanaldehyde ratio as low as 2:1 under controlled addition of 1-alkanaldehyde.
- Ganga, Venkata Subba Rao,Abdi, Sayed H.R.,Kureshy, Rukhsana I.,Khan, Noor-Ul H.,Bajaj, Hari C.
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p. 950 - 955
(2017/08/04)
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- P-Toluene sulfonic acid (PTSA)-MCM-41 as a green, efficient and reusable heterogeneous catalyst for the synthesis of jasminaldehyde under solvent-free condition
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This paper reports the synthesis of p-Toluene sulfonic acid (PTSA)-MCM-41 by impregnation method and its characterization XRD, FT-IR, TGA, N2 adsorption-desorption isotherms, SEM, and TEM. The impregnated catalysts were used to catalyse cross-aldol condensation of active methylene bearing aliphatic aldehydes with aromatic aldehydes under solvent and metal-free condition particularly in the synthesis perfumery chemical-jasminaldehyde and related compounds. The as synthesized catalyst PTSA-MCM-41 has displayed high efficiency (selectivity up to 91%) in catalyzing cross-aldol condensation reaction and was reusable (5 cycles) with no apparent loss in activity. The catalytic performance of PTSA-MCM-41 was compared with other catalysts viz., ZnO, proline, proline-LDH, PTSA, PTSA-zirconia and PTSA-zeolite where PTSA-MCM-41 showed better performance particularly in synthesis of jasminaldehyde.
- Ganga, Venkata Subba Rao,Abdi, Sayed H.R.,Kureshy, Rukhsana I.,Khan, Noor-Ul H.,Bajaj, Hari C.
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p. 264 - 271
(2016/05/19)
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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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