A nanocatalyst-assisted protocol to the synthesis of bis(pyrazolyl) methane derivatives bearing aroyl groups by the use of arylglyoxals in the presence of ZnO nanowires as a highly efficient, recyclable, and green catalyst

Abstract

An efficient, promoted three-component (2+1) catalytic reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one and arylglyoxal derivatives is described by the use of zinc oxide nanowires (ZnO NWs) as a green catalyst. By this achievement, some newly prepared bis(pyrazolyl)methane derivatives containing an aroyl group have been obtained. Starting materials were successfully condensed to obtain target products via three C–C bond formation in the presence of ZnO NWs as an efficient, cost-effective, environmentally friendly, and recyclable nanocatalyst. All synthesized products were obtained with good to excellent yields, and their structures were deduced by FTIR, 1H NMR, and 13C NMR spectroscopies and CHNS elemental analyses. It was shown that ZnO NWs can be separated, recovered after each run, and reused in further cycles (up to six runs) without significant loss of activity.