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Mn doped zirconia is utilized as an environmental-friendly and efficient catalyst for an ultrasound mediated four-component coupling reaction, containing dimethylacetylenedicarboxy late/ethyl acetoacetate, hydrazine hydrate, malononitrile, and aromatic aldehyde. These reactions were performed under green solvent conditions, to yield pyrano[2,3-c]pyrazole-3-carboxylate/pyr ano[2,3-c]pyrazole-5-carbonitrile derivatives (5a-g and 7a-g) with good to excellent yields (88-98%). The structures of thedoi:10.1016/j.arabjc.2016.04.016 fatcat:biycbtvm5nbgzfhxmg2sr23yjy