Catalytic application of green-synthesized ZnO nanoparticles in the synthesis of 1H-pyrazolo[1,2-a]pyridazine-5,8-diones and evaluation of their anti-cancer properties

In this study, Zinc Oxide Nanoparticles (ZnO NPs) produced utilizing Dill (Anethum graveolens) leaf extract and as a very efficient nanocatalyst, have been used for the green preparation of 1H-pyrazolo[1,2-a]pyridazine-5,8-diones under solvent-free conditions and 70 °C through a one-pot three-component condensation reaction of benzaldehyde derivatives, malononitrile, and maleic hydrazide. The formation of ZnO nanoparticles from Dill (Anethum graveolens) leaf extract is an easy, one-pot, inexpensive, and green process. Various characterization techniques have been utilized to inspect the structure, size, morphology, chemical composition, and optical properties of the ZnO NPs. Dill (Anethum graveolens) leaf extract is a suitable environment for producing nanosize ∼27 nm, spherical, monodisperse, wide band gap ∼3.56 eV, highly crystalline, and 1 : 1 Zn to O ratio ZnO NPs. Also, the presented protocols in this investigation have revealed several advantages such as a simple work-up procedure, good to excellent yields, short reaction times, use of a small amount of catalyst, and easy recovery of the reusable catalyst. Some products were produced and reported for the first time (entries 9–14). All products, including the newly reported ones in the present research work, were analyzed for their anti-cancer properties and the results were very promising.