Process Intensification with Bifunctional Heterogeneous Catalysts: Selective One-Pot Synthesis of 2'-Aminochalcones

Abstract

2¿-aminochalcones of pharmaceutical and commercial interest have been obtained in high yields and selectivities through one pot process using a bifunctional heterogeneous catalyst bearing base and metal active sites. This is a physical mixture material formed by a high surface area MgO and Pt on TiO2. The process involves as the first step the Claisen-Schmidt condensation between o-nitroacetophenone and benzaldehyde derivatives on the basic catalytic function. This is followed by a chemoselective hydrogenation of the nitro group in the presence of the carbonyl and double bond carbon-carbon groups within the molecule. Using the bifunctional catalyst and the reaction system proposed here it is possible to produce, under mild reaction conditions and short reaction time, 2 -aminochalcones with higher yields and selectivities than those obtained by conventional multistep methods.