“…31 Zirconium pyrophosphate nanoparticles are neutral, mild, and environmentally benign catalysts, and their remarkable performance in terms of the selectivity, reactivity, and high temperature stability have encouraged scientists to explore them for the synthesis of 1,4-dihydropyridines. 32,33 A three-component mixture of ethyl acetoacetate, aldehyde, NH 4 OAc, and ZrP 2 O 7 nanoparticles was reuxed in EtOH to afford 1,4dihydropyridines (Table 1; entry 8). The detailed investigation studies revealed that the best results were obtained using 10% mmol nanoparticles.…”