Step-economic, efficient, ZnS nanoparticle-catalyzed synthesis of spirooxindole derivatives in aqueous medium via Knoevenagel condensation followed by Michael addition
Abstract An efficient and novel green catalytic protocol for the synthesis of biologically important spirooxindole derivatives is developed in a one-pot, three-componentapproach involving substituted isatin, activated methylene reagent, and 3-methyl-1-phenyl-2-pyrazolin-5-one in water under sonication. This report describes the use of sodium chloride as a nonacidic and green catalyst for a variety