Ultrasound-assisted high-yield multicomponent synthesis of triazolo[1,2-a]indazole-triones using silica-coated ZnO nanoparticles as a heterogeneous catalyst

A schematic of silica-coated ZnO nanoparticles as a heterogeneous catalyst and ultrasound-assisted multicomponent synthesis of high-yield triazolo[1,2-a]indazole-triones and their characterization.