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

2'-Aminochalcones of pharmaceutical and commercial interest have been obtained in high yields and selectivities through a 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 times, 2'-aminochalcones with higher yields and selectivities than those obtained by conventional multistep methods.