Nanoporous AlSBA-15 catalysed Claisen–Schmidt condensation for the synthesis of novel and biologically active chalcones

Abstract

Mesoporous AlSBA-15 catalysts (nSi/nAl ratios of 41, 129 and 210) were synthesized by sol–gel method. These materials were characterized by XRD, N2 sorption, FTIR, TPD-NH3, FESEM, EDX, and TEM analysis. XRD analysis of AlSBA-15 catalysts confirmed the existence of well-ordered crystalline structure having p6mm symmetry. N2 sorption isotherm of AlSBA-15 catalysts showed a type IV adsorption isotherm with H1 hysteresis loops. SEM analysis of AlSBA-15 (41) indicated worm-like particle morphology with a size range of 3 μm with co-occurrence of smaller particles of size ca. 1 μm. TEM analysis of AlSBA-15 (41) showed existence of uniform array of tubular nano-channels. The catalytic application of AlSBA-15 catalysts was tested on industrially important chalcones synthesis via Claisen–Schmidt condensation reaction in environment friendly approach. The reaction parameters such as time, temperature, nSi/nAl ratio, catalyst amount, and catalyst stability were investigated. AlSBA-15 (41) catalyst showed an excellent catalytic performance with 98% 1-tetralone conversion with 100% selectivity of compound 1c (91% yield) within 120 min AlSBA-15 (129) and AlSBA-15 (210) catalysts. The anti-oxidant activity of the synthesised chalcones were investigated by various in-vitro procedures, including radical scavenging potentials-1, 1-diphenyl-2-picryl-hydrazil, hydrogen peroxide scavenging, and ferric reducing potential assay. The new chalcone derivatives synthesised in this work showed a very good antioxidant activity and some were found to be more active than the parent chalcones, (E)-3-(4-hydroxy-3-methoxyphenyl)-1-phenylprop-2-en-1-one (compound 8c), and standard antioxidant (curcumin).