New strategy to 1,8-dioxo-decahydroacridine derivatives using SnO2 nanoparticles via one-pot Knoevenagel condensation and Michael addition mechanisms

A versatile, convenient one-pot and three-component strategy has been promoted to prepare 1,8-dioxo-decahydroacridines in an environmentally benign solvent in using of catalytic amountsof SnO2nanoparticles. This technique is particularly appropriate for the convenient and rapidparallel synthesis of 1,8-dioxo-decahydroacridines. This technique has been compared with that ofBrφnsted acidic imidazolium salts, perfluoroalkyl tails, DBSA, and Cu-doped ZnO nanocrystallinepowder, which showed that the SnO2nanoparticles gave an improved reaction rate and yield.It also has some advantages, for example, the application of a green solvent, ease of operation,and effortlessness of purification by washing crude products with ethanol. Furthermore, thisnanoparticle catalyst was separated by a centrifuge and reused up to five times with only aninsignificant loss of catalytic efficiency.