Introducing a high throughput nanocatalytic method toward the synthesis of some pyrazolo phthalazine derivatives under green conditions utilizing imidazoliume based ionic liquid supported on the silica-coated nanosized perlite as a novel, reusable and eco-friendly nanocatalyst

A high throughput ionic liquid-based catalytic system as a new efficient and reusable heterogeneous nanocatalyst was developed for the one-pot synthesis of some 1H-pyrazolo [1,2-b] phthalazine-5,10-diones in ethanol at 78 degrees C. The designed nanocatalyst was synthesized and then characterized for their functionality, composition, size, morphology, surface properties, and crystalline size by Fourier-transform infrared spectroscopy (FTIR), Energy dispersive X-ray, Transmission electron microscopes, Field emission scanning electron microscopy, Brunauer-Emmett-Teller, and X-Ray diffraction techniques. The target products were obtained in high to excellent yields (80-96%) in this protocol. The structure of all synthesized products was determined via hydrogen nuclear magnetic resonance (H-1 NMR) and FT-IR spectra. This eco-friendly method has advantages such as a clean reaction profile, low amount of the catalyst, mild reaction conditions, environmentally benign solvent, short reaction times and high to excellent yield of products. Moreover, there is no remarkable loss in the catalytic activity of perlite NPs/SiO2/IL after six cycles of reuse. Also, the results of hot filtration studies show that leaching is not occur in catalyst surfaces and prove the complete heterogeneous behavior of perlite NPs/SiO2/IL under optimized reaction conditions.