MgO/ZrO2 Promoted with SrO and CsO as a Reusable Nano Catalysts for One Pot Synthesis of 2-Amino-2-Chromene

MgO-ZrO₂ powder (MZ30) containing 30 wt% MgO was prepared by simple precipitation method. Two other catalysts were obtained by loading MZ30 powder with 5 wt% SrO and CsO using incipient wetness impregnation method. The catalytic performance of these catalysts was evaluated for synthesis of 2-amino-2-chromene via one pot three components condensation of benzaldhyde with malononitrile and α-naphthol. Different techniques such as N₂ physisorption, TGA-DTA, XRD, TEM, Hammet indicator method and CO₂-TPD have been used to characterize the investigated catalysts. Reaction parameters such as reaction temperature, synthesis time and catalyst amount were studied to optimize the reaction conditions. The observed activity of these catalysts were correlated to their basicity and other surface parameters. Synthesis of 2-amino-2-chromene may involve moderate and strong basic sites of PKBH+ in the range ≥ 9.8 and ≤ 15.0. Base sites of PKBH+ are too weak to contribute in the synthesis processes.