Results 41 to 50 of about 3,954 (184)

Microwave Enhanced Knoevenagel Condensation of Barbituric Acid with Aromatic Aldehydes on Basic Alumina [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 2001
Efficient Knoevenagel condensation of barbituric acid with different aromatic aldehydes on basic alumina was performed in a conventional microwave over in the absence of solvent.
Ali Khalafi Nezhad, Aboulghasem Hashemi
doaj  

Styrene and Azo-Styrene Based Colorimetric Sensors for Highly Selective Detection of Cyanide

Indonesian Journal of Chemistry, 2017
A novel styrene (1) and azo-styrene (2) based chemosensor from vanillin has been successfully synthesized. Sensor 1 was obtained by one step Knoevenagel condensation of Ultrasound method and sensor 2 by coupling diazo and Knoevenagel condensation ...
Agustina Eka Prestiani, Bambang Purwono
doaj   +1 more source

Quick synthesis of isatin-derived knoevenagel adducts using only eco-friendly solvent

Results in Chemistry, 2021
A variety of knoevenagel compounds from isatin were synthesized using an eco-friendly methodology. It was used only the binary solvent ethanol: water (3:7 v/v) without the presence of metal catalyst what enabled the reaction between different isatins ...
João Marcos Gomes de Oliveira Ferreira, Girlyanderson Araújo da Silva, Maísa Cavalcanti Coelho, Claudio Gabriel Lima Junior, Juliana Alves Vale   +4 more
doaj   +1 more source

A new finding in the old Knoevenagel condensation reaction

Results in Chemistry, 2022
Reaction of benzaldehyde (5a) with defined quantities of ethyl cyanoacetate (6) in presence of piperidine was studied. In a neat condition, hexasubstituted cyclohexeneamine (7a) with three ester substituents was formed along with ethyl acrylate (9a ...
Attimogee Shivamurthy Harisha, Kuppuswamy Nagarajan, S.Saravanan, Venkat Manohar, Sajesh P. Thomas, Tayur Narasingarow Guru Row   +5 more
doaj   +1 more source

A Chiral Saddle‐Shaped Nanographene With Two Heptagon‐Embedded [4]Helicenes

Angewandte Chemie International Edition, EarlyView.
We present a novel synthetic strategy toward a chiral saddle‐shaped nanographene (cSNG) via a two‐step oxidation of a prochiral anthracene precursor. The Scholl‐type oxidation first yields a key intermediate with sp3‐defect heptagons, and subsequent oxidative dehydrogenation affords fully conjugated cSNG.
Felix Trautner, Boris Borrisov, Philipp Royla, Hongqing Zhao, Hartmut Komber, Li Wan, Evgenia Dmitrieva, Ji Ma, Jan J. Weigand, Qun Yang, Xinliang Feng, Wenhui Niu   +11 more
wiley   +1 more source

Hydroxyapatite supported caesium carbonate as a new recyclable solid base catalyst for the Knoevenagel condensation in water

Beilstein Journal of Organic Chemistry, 2009
The Knoevenagel condensation between aromatic aldehydes and malononitrile, ethyl cyanoacetate or malonic acid with hydroxyapatite supported caesium carbonate in water is described.
Monika Gupta, Rajive Gupta, Medha Anand
doaj   +1 more source

Synthesis of biscoumarin derivatives by the reaction of aldehydes and 4-hydroxycoumarin using ruthenium (III) chloride hydrate as a versatile homogeneous catalyst [PDF]

Journal of the Serbian Chemical Society, 2012
The one-pot domino Knoevenagel-type condensation/Michael reaction of aromatic, heteroaromatic and aliphatic aldehydes with 4-hydroxycoumarin in aqueous media in the presence of ruthenium salt as homogeneous catalyst was investigated. It was found that
Tabatabaeian Khalil, Heidari Hannaneh, Khorshidi Alireza, Mamaghani Manouchehr, Mahmoodi Nosrat O.   +4 more
doaj   +1 more source

Polyvinyl amine as a modified and grafted shell for Fe3O4 nanoparticles: As a strong solid base catalyst for the synthesis of various dihydropyrano[2,3-c]pyrazole derivatives and the Knoevenagel condensation

Journal of Saudi Chemical Society, 2019
In this work, we reported one-step deposition of polyacrylamide on nano-magnetite surface via a simple and in situ polymerization of acryl amide to form n-Fe3O4/PAM nanocomposite. The amide (–CONH2) groups could be converted easily to amine (–NH2) groups
Maryam Arghan, Nadiya Koukabi, Eskandar Kolvari   +2 more
doaj   +1 more source

Synthesis of Vanillic Acid—Meldrum’s Acid Conjugate

Molbank
A vanillic acid—Meldrum’s acid conjugate with a 1,2,3-triazole linker is synthesized. The reaction sequence foresees the Huisgen reaction and the Knoevenagel condensation as the key-steps.
Laima Bērziņa, Inese Mieriņa
doaj   +1 more source

Organocatalytic Formal (3+2+1)‐Cycloaddition of Allenoates, Michael Acceptors, and Carbaldehydes

Chemistry – A European Journal, EarlyView.
The use of secondary amine Lewis base organocatalysts allows for the unprecedented activation of allenoates for formal (3+2+1)‐cycloadditions with Michael acceptors and aromatic carbaldehydes. ABSTRACT Employing secondary amines as covalently interacting Lewis basic organocatalysts allows for the activation of electron‐deficient allenes (allenoates ...
David Naderer, Alexander Pötscher, Katharina Eder, Uwe Monkowius, Markus Himmelsbach, Mario Waser   +5 more
wiley   +1 more source