In this work, synthesis of pyranopyrazole derivatives by the one-pot tandem four component condensation reaction of aryl aldehydes with ethyl acetoacetate, malononitrile, and hydrazine hydrate in the presence of Ph3CCl at 60 C under neutral, mild, and solvent-free conditions has been reported. Mechanistically, it is interesting that trityl chloride by in situ generation of trityl carbocation (Ph3C?) promotes the reaction.
