The synthesis of pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolines via a one-pot three-component reaction by using benzene-1,2-dicarbaldehyde, trimethylsilylcyanide and various pyridin-2-amines in the presence of a catalytic amount of superparamagnetic nano-Fe3O4@SiO2 anchored sulfuric acid in ethanol in good-to-high yields is described.
![Graphical abstract: One-pot three-component synthesis of pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolines using Fe3O4@SiO2–OSO3H as an efficient heterogeneous nanocatalyst](http://hg.y866.cn/compound/lib/scimg/usr/1/C4RA10856F.jpg)