78831-18-2Relevant academic research and scientific papers
Simple and ecofriendly synthesis of dihydropyrimidinones (thiones), dihydropyridines, and pyridines using 3-formylchromones as substrates assisted by a recyclable Preyssler heteropolyacid
Sanchez, Laura M.,Pasquale, Gustavo,Sathicq, ángel,Ruiz, Diego,Jios, Jorge,Ferreira de Souza, Andrea L.,Romanelli, Gustavo P.
, p. 295 - 305 (2016/10/11)
Several dihydropyrimidinones/thiones, 1,4-dihydropyridines, and pyridine derivatives were prepared in very good yields and purity values. The corresponding reactions were carried out by employing a bulk Preyssler heteropolyacid H14[NaP5/s
Solvent-free synthesis of functionalized pyridine derivatives using Wells-Dawson heteropolyacid as catalyst
Sanchez, Laura M.,Sathicq, Angel G.,Jios, Jorge L.,Baronetti, Graciela T.,Thomas, Horacio J.,Romanelli, Gustavo P.
, p. 4412 - 4416 (2011/09/19)
Wells-Dawson heteropolyacids (H6P2W 18O62·24H2O) were used as catalysts in the Hantzsch-like multicomponent condensation reaction with 3-formylchromones as aldehyde component, a β-ketoester and ammonium acetate, under solvent-free conditions at 80 °C. Although the desired products were obtained, functionalized pyridines were the main reaction product and became the alternative route to dihydropyridine ring formation. Based on the proposed mechanisms for the formation of each of the obtained products, the multicomponent reaction was modified to afford only the functionalized pyridines (60-99%). Our procedure represents a clean alternative for the synthesis of several highly functionalized pyridines.
The Synthesis of Pyridine Derivatives from 3-Formylchromone
Hass, Georges,Stanton, James L.,Sprecher, Andreas von,Wenk, Paul
, p. 607 - 612 (2007/10/02)
3-Formylchromone (1) reacts with active methylene derivatives to yield condensation products 2a-d, 10, 11 and 12.Treatment of 2a-d with ammonia or methylamine gives pyridines 3-6.Alternatively, reaction of 1 with enamine derivatives yields pyrido compounds 15,17,19,21,23 and 28 in one step.Factors determining the formation and regiospecifity of the pyridine ring forming reactions are also discussed.
