Efficient CAN catalyzed synthesis of 1H-indazolo[1,2-b] phthalazine-1,6,11-triones: An eco-friendly protocol

A convenient, economical and green approach to the synthesis of 1 H -indazolo[1,2- b ]phthalazine-1,6,11-trione derivatives has been achieved via a one-pot protocol using phthalhydrazide, a cyclic-β-diketone and an aldehyde in the presence of a ceric ammonium nitrate catalyst in polyethylene glycol. The simple work up, mild conditions, excellent yields, inexpensive and non-toxic catalyst and simple solvent recyclability render this protocol both attractive and economically viable.