Results 91 to 100 of about 200 (108)

Basic ionic liquid-catalyzed multicomponent synthesis of tetrahydrobenzo[b]pyrans and pyrano[c]chromenes

Mendeleev Communications, 2011
Triethylenetetraammonium trifluoroacetate-catalyzed condensation of benzaldehydes, malononitrile and cyclic 1,3-dioxo compounds in aqueous medium affords the corresponding fused 2-amino-4-aryl-3-cyanopyrans.
Jia Zheng, Yiqun Li
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ChemInform Abstract: Facile and Efficient Access to Tetrahydrobenzo[b]pyrans Catalyzed by N,N‐Dimethylbenzylamine.

ChemInform, 2016
AbstractTitle compounds are efficiently synthesized through a one‐pot, three‐component Knoevenagel—Michael—Thorpe—Ziegler cyclization sequence catalyzed by N,N‐dimethylbenzylamine.
Hamzeh Kiyani, Mozhgan Sadat Jalali
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ChemInform Abstract: A Revisit to the Hantzsch Reaction: Unexpected Formation of Tetrahydrobenzo[b]pyrans Beyond Polyhydroquinolines.

ChemInform, 2011
AbstractThe reaction of dimedone (Ia) with aldehydes (V) and malononitrile in the presence of equimolar amount of NH4OAc yields unexpected tetrahydrobenzopyrans instead of quinolines.
Kedar A. Undale, YoonKook Park, Kyungmoon Park, Dilip H. Dagade, Dattaprasad M. Pore   +4 more
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Facile pathway for synthesis of two efficient catalysts for preparation of 2-aminothiophenes and tetrahydrobenzo[b]pyrans

Research on Chemical Intermediates, 2017
We report here a new magnetically recyclable catalyst consisting of iron-substituted Keggin-type heteropolyacid (HPA) grafted on modified Fe3O4 nanoparticles. The synthesized hybrid nanomaterial exhibited the excellent catalytic efficiency in condensation reaction for the preparation of tetrahydrobenzo[b]pyrans under solvent-free conditions as well as ...
Hamid Reza Saadati-Moshtaghin, Farrokhzad Mohammadi Zonoz   +1 more
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Polyaniline/SiO2 Catalyzed One-pot Synthesis of Tetrahydrobenzo[b]pyran Derivatives

2010
Polyaniline/SiO2 is an efficient catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives from a one-pot, three component, condensation of aldehydes, malononitrile and dimedone at room temperature. This protocol has several advantages such as high yield, a simple work up procedure, low toxicity and easy recovery and reusability of the ...
Yelwande, Ajeet A., Arbad, Balasaheb R., Lande, Machhindra K.   +2 more
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Synthesis of tetrahydrobenzo[b]pyran and 3,4-dihydropyrimidinone derivatives using glutamic acid as an efficient catalyst

Inorganic and Nano-Metal Chemistry, 2016
ABSTRACTThe efforts to use green catalysts for organic synthesis are undeniable. Natural catalysts are biodegradable and easy to access. Herein, glutamic acid was applied as a natural and green catalyst for the synthesis of tetrahydrobenzo[b]pyran and 3,4-dihydropyrimidinone derivatives under solvent-free and thermal conditions.
Khatereh Khandan-Barani, Mehrnoosh Kangani, Maryam Mirbaluchzehi, Zahra Siroos   +3 more
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Potassium Phosphate Catalyzed a Rapid Three-Component Synthesis of Tetrahydrobenzo[b]pyran at Ambient Temperature

Catalysis Letters, 2009
An efficient, rapid, one-pot synthesis of tetrahydrobenzo[b]pyran is achieved via a three-component reaction of aldehydes, 1,3-diketone, malononitrile in 20% ethanol using anhydrous potassium phosphate as a catalyst at room temperature. The key advantages are the short reaction time, high yields, simple work-up, inexpensive catalyst and purification of
D. M. Pore, K. A. Undale, B. B. Dongare, U. V. Desai   +3 more
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β-Cyclodextrin as an efficient catalyst for the one-pot synthesis of tetrahydrobenzo[b]pyran derivatives in water

Research on Chemical Intermediates, 2015
Various 4H-benzo[b]pyran derivatives were synthesized via a one-pot three-component condensation of arylaldehyde, malononitrile and dimedone in water using β-cyclodextrin (β-CD) as an efficient catalyst. This method provides several advantages, including mild reaction conditions, operational simplicity, high yields and minimal pollution of the ...
Jun Lu, Xue-wen Fu, Ge Zhang, Chun Wang
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Three-Component Synthesis of Tetrahydrobenzo[b]pyrans Catalyzed by Sodium Cyclamate

HETEROCYCLES, 2022
Hamzeh Kiyani, Fatemeh Baghaie
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Electrochemical synthesis of tetrahydrobenzo[b]pyran derivatives in deep eutectic solvents

Journal of Electroanalytical Chemistry, 2022
Eman O. Osman, Amr M. Mahmoud, Sally S. El-Mosallamy, Hala B. El-Nassan   +3 more
openaire   +1 more source