Title:Bentonite Catalyzed an Efficient and Green Synthesis of Arylidene Meldrum's Acid Derivatives in Aqueous Media
Volume: 18
Issue: 7
Author(s): Mahdieh Yahyazadehfar, Sayed Ali Ahmadi*, Enayatollah Sheikhhosseini and Dadkhoda Ghazanfari
Affiliation:
- Department of Chemistry, Kerman Branch, Islamic Azad University, Kerman,Iran
Keywords:
Arylidene Meldrum's acid, Bentonite (Al2O3.4SiO.H2), Knoevenagel condensation, aqueous media, natural
catalyst, electron-donating.
Abstract: In the present paper, a simple, highly efficient, and environmentally friendly protocol
was proposed for the Knoevenagel condensation reaction of aromatic aldehydes using Meldrum’s acid
(2,2-dimethyl-4,6-dioxo-1,3-dioxane) with bentonite as an available non-toxic mineral catalyst exposed
to aqueous media under green conditions. Together with the substitution protocol of electron-donating
or -withdrawing groups, all reactions were finalized from 5 to 120 min in water at 90°C. With regard to
such reactions, the purification of columns on products was not a requirement. Considering the environmental
aspect, use of water as a green solvent, utilization of a reusable catalyst, simple work-up
process and steps, as well as rapid reaction times were taken into account as some characteristics of
these chemical reactions.