One-pot and efficient synthesis of triazolo[1,2-a]indazole-triones catalyzed by poly(ethylene glycol) based magnetic dicationic ionic liquid

An atom-efficient, eco-friendly, solvent-free, high yielding, multicomponent green strategy to synthesize triazolo[1,2-a]indazole-triones derivatives by the one-pot condensation of aldehyde, dimedone, and phenyl urazole is presented. A series of different substituted aromatic aldehydes including either electron-withdrawing or electron-donating groups used in this reaction participated well and gave the corresponding products in good to excellent yield. Poly (ethylene glycol) based magnetic room temperature dicationic ionic liquid, PEG-MRTDIL, was prepared by mixing PEG-DIL with anhydrous FeBr3 under neat conditions. The catalyst was studied by UV and IR spectroscopy. This method provides several advantages such as environment benign, high yield, simple work up procedure and reusable catalyst.