ChemInform Abstract: Facile ZrCl₄ Promoted Four‐Component Coupling One‐Pot Synthesis of Polyhydroquinoline Derivatives Through Unsymmetric Hantzsch Reaction.

Abstract

The catalyst can be recovered by filtration and reused efficiently. -(REDDY*, C. S.; RAGHU, M.; Indian J.

A clean procedure for the synthesis of 1,4-dihydropyridines via Hantzsch reaction in water

“…[10] Additionally, this method has difficulty in the synthesis of different substituted biologically active Hantzsch esters derivatives. Then, some improved synthetic methods for preparing these 1,4-DHPs compounds have been reported by condensation of aldehydes, ammonium salts, and b-keto esters in the presence of Lewis acid, [11,12] Bronsted acid,[13Á15] solid acid, [16] base, [17,18] biocatalysts, [19,20] organocatalysts [21], and ionic liquids [22,23] as catalysts. Recently, the progress of modified Hantzsch reactions in aqueous medium, solvent-, and/or catalyst-free synthesis has attracted the attention of chemists because they are environmentally benign processes.…”