نتایج جستجو برای: pot condensation

تعداد نتایج: 46127  

Journal: :journal of sciences, islamic republic of iran 2014
b. pouramiri e. tavakolinejad kermany h. khajesamani h. khabazzadeh

an improved, simple, and facile synthesis of 3,4-dihydropyrimidin-2(1h)-ones by employing three-component, one-pot condensation reaction of β-keto ester, aromatic aldehydes, and urea or n-methylurea using lacl3/clch2cooh as an inexpensive and green chemistry catalyst system under solvent-free conditions described. compared with the classicalbiginelli reaction conditions, this method has the adv...

2012
Aleksandra Pałasz

ABSTRACT Knoevenagel condensation of barbituric acids with aromatic aldehydes containing one or two formyl groups was carried out. 5-Arylidenebarbituric acids underwent smooth hetero-Diels-Alder (HDA) reactions with enol ethers to afford cis and trans diastereoisomers of pyrano[2,3-d]pyrimidine-2,4-diones and 5,5'-(1,4-phenylene)bis[2H-pyrano[2,3-d]pyrimidine-2,4(3H)-dione] derivatives in excel...

Journal: :شیمی کاربردی 0
سید محمد وحدت مریم خاورپور فرج اله محمدزاده

nano tin dioxide was employed as a catalyst for efficient and facile preparation of pyran derivatives via the one-pot three component condensation reaction of various aldehydes with malononitrile and dimedone. chromene derivatives via the one-pot three component condensation reaction of various aldehyde with malononitrile and 4-hydroxycoumarin were also synthesized by this novel catalyst. the d...

Journal: :iranian journal of catalysis 2015
amit waghmare shivaji pandit

(diacetoxyiodo)benzene has been used as an efficient catalyst for an improved and rapid one-pot synthesis of biscoumarin derivatives in excellent yield under reflux condition using water as a environmentally benign reaction medium. this aqua mediated knoevenagel condensation of various aromatic and hetero-aromatic aldehydes with 4-hydroxycoumarin using catalytic amount of (diacetoxyiodo)benzene...

Journal: :iranian journal of catalysis 2011
farhad shirini seyyed vahid atghia meysam alipour khoshdel

an efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline tio2 under solvent free conditions. the reported method is mild, rapid and has the advantages su...

Journal: :Organic & biomolecular chemistry 2017
Harekrushna Behera Venkatachalam Ramkumar Nandita Madhavan

Correction for 'Triamide macrocyclic chloride receptors via a one-pot tandem reduction-condensation-cyclization reaction' by Harekrushna Behera, et al., Org. Biomol. Chem., 2017, DOI: .

Journal: :Organic letters 2013
Li-Jin Dong Tian-Tian Fan Chao Wang Jian Sun

The self-condensation of alkynals was for the first time implemented under mild organocatalytic conditions and was successfully linked with a domino organocatalytic inverse-electron-demand oxa-Diels-Alder reaction, which led to the development of a facile one-pot method to produce a wide variety of polysubstituted chiral 3,4-dihydropyrans with good to high yields and diastereoselectivities and ...

(Diacetoxyiodo)benzene has been used as an efficient catalyst for an improved and rapid one-pot synthesis of biscoumarin derivatives in excellent yield under reflux condition using water as a environmentally benign reaction medium. This aqua mediated Knoevenagel condensation of various aromatic and hetero-aromatic aldehydes with 4-hydroxycoumarin using catalytic amount of (diacetoxyiodo)benzene...

Journal: :iranian journal of catalysis 2014
hossein naeimi zahra sadat nazifi

efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by knoevenagel condensation, michael addition and cyclodehydration of dimedone. this reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific brønsted acidic ionic liquid under solvent free conditions. the catalyst could be recycled five times without si...

Journal: :journal of the iranian chemical research 0
gholam hossein mahdavinia chemistry department, islamic azad university, marvdasht branch, marvdasht, iran

an efficient one-pot condensation for the synthesis of 1,8-dioxo-octahydroxanthene is  achieved through a condensation of aryl aldehydes and 5,5-dimethyl-1,3-cyclohexandione in the presence of  nbs. this method enjoys several advantages such as low cost, simple work up procedure and safe reaction condition. in addition, water was chosen as a green solvent.

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