Three-component coupling reactions in ionic liquids: an improved protocol for the synthesis of 1,4-dihydropyridines

Abstract

Three-component condensation of aldehyde, b-ketoester and methyl 3-aminocrotonate proceeds smoothly in 1-n-butyl-3-methylimidazolium tetrafluoroborate [bmim]BF 4 or 1-n-butyl-3-methylimidazolium hexafluorophosphate [bmim]PF 6 ionic liquids at room temperature under mild conditions to afford the corresponding 1,4-dihydropyridine derivatives in high yields. The recovered activated ionic liquids are recycled for four to five runs with no loss in activity.

Six‐Membered Heterocycles: Pyridines

“…Remarkable improvement of the reaction conditions has been reported, including the promotion by microwave [115], TMSCl, ionic liquid [116], Bu 4 NHSO 4 [117] and supported reagents [118].…”

The Phosphorus Aspects of Green Chemistry: the Use of Quaternary Phosphonium Salts and 1,3-Dialkylimidazolium Hexafluorophosphates in Organic Synthesis

“…A variety of catalysts, such as alkali hydroxide [135], a bis(amine) salt [136] and hydrotalcyte [137] was tested (Scheme 76). Finally, a tricomponent condensation involving an aldehyde, a -ketoester and methyl 3-aminocrotonate gave rise to 1,4-dihydropyridines (Scheme 77) [135].…”

Functionalized calix[4]arene-based receptor for saccharide recognition

“…Many synthetic methods for the Electronic supplementary material The online version of this article (doi:10.1007/s10847-015-0540-9) contains supplementary material, which is available to authorized users. synthesis of 1,4-dihydropyridines [28][29][30][31][32][33][34] and pyrimidine [35][36][37][38] derivatives have been reported but into the best of our knowledge there is no report for the synthesis of functionalized-calix [4]arene derivatives with 1,4-dihydropyridine or pyrimidine compound.…”