Ultrasound mediated green synthesis of pyrano[2,3-c]pyrazoles by using Mn doped ZrO2

Suresh Maddila, Sridevi Gorle, Sebenzile Shabalala, Oluwaseun Oyetade, Surya Narayana Maddila, Palakondu Lavanya, Sreekantha B. Jonnalagadda
2016 Arabian Journal of Chemistry  
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 the
more » ... ompounds were identified and confirmed by 1 H NMR, 15 N NMR, 13 C NMR, FT-IR and HR-MS spectral data. The prepared catalyst Mn/ZrO 2 was synthesized and fully characterized by various techniques including P-XRD, BET, SEM and TEM analysis. The main benefits of this process are short reaction times, easy work-up, reusability of the catalyst and no chromatographic purifications.
doi:10.1016/j.arabjc.2016.04.016 fatcat:biycbtvm5nbgzfhxmg2sr23yjy