Ulva fasciata-mediated preparation of zinc oxide nanocrystalline for one-pot multicomponent synthesis of 6-amino-3-methyl-4-phenyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile

Abstract

ZnO has been successfully prepared by a simple co-precipitation method using sodium hydroxide, zinc acetate as precursor and Ulva fasciata polysaccharides as capping agent. Characterization using FTIR, XRD and SEM-EDS indicated the successful formation of ZnO nanocrystalline with crystallite size of 27.01 nm. In order to promote ZnO as a green catalyst, its application for one-pot multicomponent pyranopyrazole synthesis has been performed. Several reaction conditions have been investigated, and the highest yield (98%) was observed in the use of 10% mole of ZnO at room temperature for 90 min reaction time in aqueous medium to produce 6-amino-3-methyl-4-phenyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile.