Results 131 to 140 of about 9,597,280 (150)

A facile and efficient synthesis of tetrahydrobenzo[b]pyrans using lactose as a green catalyst

Research on Chemical Intermediates, 2014
Lactose has been used as a mild, efficient, green, and inexpensive catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives via a one-pot, three-component condensation between aryl aldehydes, malononitrile, and dimedone in H2O:EtOH at 60 °C.
Fatemeh Noori Sadeh, Malek Taher Maghsoodlou, Nourallah Hazeri, Mehrnoosh Kangani   +3 more
openaire   +1 more source

Preparation and characterization of magnetite-dihydrogen phosphate as a novel catalyst in the synthesis of tetrahydrobenzo[b]pyrans

Materials Chemistry and Physics, 2017
Abstract A novel inexpensive, efficient, environmentally-benign, and magnetically recoverable nanomaterial consisting of dihydrogen phosphate ions supported on silica-coated magnetite nanoparticle was prepared. The synthesized nanomaterial was characterized with FT-IR, XRD, FE-SEM, TEM, ICP and VSM.
Hamid Reza Saadati-Moshtaghin, Farrokhzad Mohammadi Zonoz   +1 more
openaire   +1 more source

Application of mesoporous silicate-magnetic compounds in the synthesis of tetrahydrobenzo[b]pyran

Chemistry and Nanochemistry,4(4 ...
Karami, Masoomeh, Sanaeishoar, Haleh
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source