In-water facile synthesis of poly-substituted 6-arylamino pyridines and 2-pyrrolidone derivatives using tetragonal nano-ZrO2 as reusable catalyst†
Abstract
Here, we report a facile synthetic protocol to access a series of ethyl 5-cyano-2-methyl-4-aryl-6-(arylamino)nicotinates and ethyl 4-hydroxy-2-(4-nitroaryl)-5-oxo-1-aryl-2,5-dihydro-1H-pyrrole-3-carboxylates using tetragonal nano-ZrO2 as reusable catalyst. It was observed that the ZrO2 nanoparticles were stable during reaction and apparently no leaching of Zr-content occurred when the catalyst was recycled eight times.