Abstract
Abstract A novel silica tungstic acid (STA) as a highly efficient catalyst has been synthesized and employed for the cyclocondensation of 1,2-phenylenediamines with orthoesters under solvent-free conditions. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding benzimidazoles at 80 °C. To make the catalyst, sodium tungstate reacted with silica chloride under refluxing n-hexane. The STA as a novel solid acid was characterized by X-ray fluorescence, X-ray diffraction, and Fourier transform infrared spectroscopy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have