White-light-emitting diode (LED)-promoted one-pot synthesis of 1,2-dihydropyrimido[1,2-a]benzimidazoles in the presence of a new spiky magnetic nanocatalyst and their anthelmintic studies

Abstract

Spiky Ni-nanoparticles were successfully synthesized and characterized using different analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), field electron scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), powder XRD, vibrating-sample magnetometry (VSM), and energy-dispersive X-ray spectroscopy (EDS). These nanoparticles, which exhibited a large surface area and magnetic properties, were meticulously used for the synthesis of 1,2-dihydropyrimido[1,2-a]benzimidazole and its derivatives from an aromatic aldehyde, active methylene compounds, and 2-aminobenzimidazole at room temperature under white LED irradiation. This method capitalizes on mild and environmentally friendly reaction conditions, high selectivity, and excellent yield of products, as well as the recyclability and reusability of the catalyst. In addition, the prepared benzimidazole derivatives 6d, 6k, and 8e exhibited positive anthelmintic activity against S. obvelata, a model gastrointestinal nematode.