نتایج جستجو برای: chalcones
تعداد نتایج: 1021 فیلتر نتایج به سال:
3-Acetyl-4-hydroxycoumarin (2) was reacted with some aldehydes (4-chlorobenzaldehyde, 4-bromobenzaldehyde, 5-methylfurfural) to afford the chalcones (3a-c). Cyclization of these chalcones with malononitrile in the presence of ammonium acetate afforded pyridine carbonitriles (4a-c), while the cyclization reaction of chalcones (3a-c) with ethyl cyanoacetate afforded the oxopyridine carbonitriles ...
Over the past several decades, photopolymerization has become an active research field, and ongoing efforts to develop new photoinitiating systems are supported by different applications in which this polymerization technique is involved—including dentistry, 3D 4D printing, adhesives, laser writing. In search for structures, bis-chalcones that combine two chalcones’ moieties within a unique str...
The synthesis and characterization of some novel Pyrimidine derivatives have been presented. Acylation of resorcinol followed by nuclear prenylation with isoprene gives Chroman. Chroman on treatment with p-substituted benzaldehydes affords substituted chalcones. Pyrimidines have been prepared from chalcones by condensing with Guanidine hydrochloride in alkali medium. The structure of Pyrimidine...
Natural or synthetic chalcones with different substituents have revealed a variety of biological activities that may benefit human health. The underlying mechanisms of action, particularly with respect to the direct cellular targets and the modes of interaction with the targets, have not been rigorously characterized, which imposes challenges to structure-guided rational development of therapeu...
Chalcones, precursors of open chain flavonoids and isoflavonoids present in edible plants, and their derivatives have attracted increasing attention due to numerous potential pharmacological applications. They have displayed a broad spectrum of pharmacological activities. Changes in their structure have offered a high degree of diversity that has proven useful for the development of new medicin...
The first phase-transfer catalyzed cyclopropanation reaction of chalcones using bromomalonates as the nucleophiles in a Michael Initiated Ring Closing reaction (MIRC) was developed. Key to success was the use of a free OH-containing cinchona alkaloid ammonium salt catalyst and carefully optimized liquid/liquid reaction conditions. The reaction performed well for electron neutral and electron de...
BACKGROUND 1,3-Diphenylpropenones (chalcones) are well known for their diverse array of bioactivities. Hydroxyl group substituted chalcones are the main precursor in the synthesis of flavonoids. Till date various methods have been developed for the synthesis of these very interesting molecules. Continuing our efforts for the development of simple, eco-friendly and cost-effective methodologies, ...
A series of 2'-hydroxy-chalcones and their oxidative cyclization products, aurones, have been synthesized and tested for their antioxidant and lipoxygenase inhibitory activity. The natural product aureusidin (31) was synthesized in high yield by a new approach. An extensive structure-relationship study was performed and revealed that several chalcones and aurones possess an appealing pharmacolo...
A series of chalcones, dihydropyrimidinone and dihydropyrimidinethione derivatives were synthesized in good yields by Claisen Schmidt reaction of acetophenones with substituted aldehydes in the presence of sodium hydroxide in water-ethanol mixture followed by the condensation reaction of chalcones with urea and thiourea in ethanol respectively. The structures of the synthesized compounds were e...
Chalcones are still challenge substrates in Michael reactions, and only limited success has been achieved. This work describes a highly enantioselective Michael addition of diethyl malonate with chalcones catalyzed by cinchona alkaloids-derivatived bifunctional tertiary amine-thioureas bearing multiple hydrogen-bonding donors.
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