Simple method for the synthesis of 1H-Indazolo [2,1-b]phthalazine-triones via one pot three component condensation of phthalhydrazide, aldehyde and dimedone catalyzed by orthophosphoric acid in water-phenol system is reported. This synthetic procedure proves with extremely lower reaction timings, high yields, recyclable of catalyst and green solvent system.
1H-Indazolo[2,1-b]phthalazinetrione, Multi component reactions, Orthophosphoric acid, Water-phenol system