Synthesis of quinoxalines in the presence of kaoline based magnetic nanocatalyst

Quinoxaline and its derivatives are an important class of heterocycles displaying a broad spectrum of biological activities which have made them privileged structures in combinatorial drug discovery libraries [1]. Quinoxalines play an importantrole as a basic skeleton for the design of a number of antibioticssuch as echinomycin, actinomycin, and leromycin [2]. Quinoxalines synthesis has been done by using of catalysts CuSO4.5H2O, Ga(OTf)3 [1,2]. Kaolin is very cheap and abundant raw material and has a variety of industrial uses. It is a layered silicate comprised of platelets that are interacting by means of strong hydrogen bonding between them [3]. The SEM of kaoline shows that the particle size is nanometer scale. Nano- kaoline BF3/ Fe3O4as an efficient supported Lewis acid catalyst, was synthesized via reaction of nanokaoline BF3 with nano-Fe3O4 indichloromethane underultrasonic condition. Nano-kaoline BF3/ Fe3O4 catalyzed reactions of 1,2-phenylen diamines and 1,2-diketones to produce quinoxalines in excellent to quantitative yields. The reactions proceed under solvent free and room temperature conditions. In conclusion, this procedure has many advantages such as mild reactions, easy work- up and good to excellent yields.