Synthesis of 9-Arylhexahydroacridine-1,8-diones Using Phosphate Fertilizers as Heterogeneous Catalysts

A new strategy has been proposed for the synthesis of 9-arylhexahydroacridine-1,8-diones by three-component condensation of aromatic aldehydes with 5,5-dimethylcyclohexane-1,3-dione and ammonium acetate in ethanol, using nontoxic, available, and inexpensive phosphate fertilizers [monoammonium phosphate (MAP), diammonium phosphate (DAP), and triple super phosphate (TSP)] as heterogeneous catalysts. Notable advantages of the proposed method include operational simplicity, low cost of the reactants, favorable environmental profile, good yield, short reaction time, recovery and reuse of the catalyst, and valorization of Moroccan natural phosphate.