Bisulfate-functionalized dicationic ionic liquid grafted with silica-coated nano-Fe3O4 (nano-[Fe3O4@SiO2@BDIL] or NFSBDI) was synthesized as a novel nanomagnetic material, and its structure was confirmed by EDS, FE-SEM, FT-IR, VSM, XRD and TGA. Afterward, it was utilized as an efficient, magnetically recyclable and dual-functional catalyst for the preparation of an important class of uracil-containing heterocycles, namely pyrimido[4,5-b]quinolines. The one-pot multicomponent reaction of dimedone, arylaldehydes and 6-amino-1,3-dimethyluracil in the presence of NFSBDI under solvent-free conditions afforded pyrimido[4,5-b]quinolines in high yields and short times.