FSG-Hf(NPf2)4 catalyzed, environmentally benign synthesis of 1,8-dioxo-decahydroaridines in water–ethanol

An efficient, eco-friendly and simple work-up procedure for the synthesis of 1,8-dioxo-decahydroacridines has been developed through one-pot condensation reaction of aromatic aldehyde, 5,5-dimethyl-1,3-cyclohexanedion and different aromatic amine or ammonium acetate in the presence of a catalytic amount of FSG supported Hf(NPf2)4 as a stable and recyclable catalyst under water–ethanol (1:1, v/v). This protocol was found to be applicable to obtain a diverse range of 1,8-dioxo-9-aryl-decahydroacridine derivatives in 49–83% isolated yields and the catalyst was recycled for three cycles.