Nano Fe2O3@SiO2–SO3H: efficient catalyst for the multi-component preparation of indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidine-2,4,6(3H)-trione derivatives

A highly efficient multi-component reaction of structurally diverse aryl aldehydes, 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione and 1H-indene-1,3(2H)-dione using nano Fe2O3@SiO2–SO3H as a catalyst is described. The products are a variety of indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidine-2,4,6(3H)-trione derivatives. The effect of the solvent on the product selectivity was investigated. The morphology, particle size distribution, and some properties of Fe2O3@SiO2–SO3H nanopowders have been characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD), N2 adsorption–desorption isotherms and thermogravimetric analysis (TGA) techniques.