A Recoverable PANI/α-Fe2O3 Nanocatalyst for Ultrasound-Assisted Knovenagel Condensation

Abstract

In this research work, a new PANI/α-Fe2O3 (PANI = polyaniline) nanocatalyst was prepared and applied to ultrasound-assisted Knoevenagel condensation reaction using ultrasound waves at ambient temperature. The ultrasound-assisted synthesis is a quick, green and efficient C–C bond formation reaction method. Many parameters of the condensation reaction were optimized, such as irradiation time, types of solvent, screening of catalyst and its amount. The results showed that the yields from the ultrasound-assisted reactions were higher than from non-irradiated responses as well as other conventional routes of synthesis. The prepared catalyst was characterized via SEM-EDS, FTIR, DLS and XRD studies. The stability and catalytic performance of the PANI/α-Fe2O3 were good and it could be reused six times without loss in catalytic activity. The dinitrile molecules were synthesized by Knoevenagel condensation and characterized by FTIR and NMR techniques. Compared to the reported work, the present protocol has numerous benefits such as economical, simplistic workup, high yields and, an environmentally gentle method with a shorter reaction time.