Eco-friendly strategy: design and synthesis of biologically potent benzimidazole–amine hybrids via visible-light generated oxidative C–H arylamylation of analenic amidines.

An operationally simple visible light mediated intramolecular cyclization of benzimidazole to 2-amino benzimidazole hybrid. The disclosed procedure is rapid and the convenient synthesis of benzimidazole–amine hybrids from easily available substituted cyclic, acyclic amines, and benzimidazole under neat conditions in the presence of catalyst tris(2,2-bipyridine)ruthenium(II) chloride. Indubitably this methodology gives a facile and straightforward pathway to construct benzimidazole–amine hybrid derivatives in an eco-friendly fashion. The reaction proved to be economical interims of product yield, low loading of catalyst under solvent free condition. The solvent free method has supreme importance in industrial research. The scope and efficiency of this new green method is significantly better than the existing methods. [ABSTRACT FROM AUTHOR]