A green route for the synthesis of 2-substituted benzoxazole derivatives catalyzed by Al3+-exchanged K10 clay

A new, simple, and efficient protocol is developed for the synthesis of 2-substituted benzoxazole derivatives through N-C-O bond formation using Al3+-exchanged K10 clay (Al3+-K10) as catalyst. A wide range of benzoxazole derivatives are synthesized in high yields without affecting many functional groups. Hot filtration experiments showed the absence of metal leaching and catalyst can be reused for five times with only a slight decrease in yield.