Silica-zinc chloride (SiO2-ZnCl2) catalyzed Michael addition reaction of active methylene compounds to β-nitrostyrenes: Synthesis of functionalized pyrazole derivatives

Abstract

Under solvent-free conditions, a simple and efficient procedure has been developed for the Michael addition reaction of active methylene compounds to β-nitrostyrenes. The resulting Michael adducts are efficiently converted into functionalized pyrazole derivatives with hydrazine hydrate in excellent yields. All the compounds were well characterized by spectroscopic techniques.