Surfactant modified bentonite (CTMAB-bentonite) as a solid heterogeneous catalyst for the rapid synthesis of 3,4-dihydropyrano[c]chromene derivatives

•Application of CTMAB-bentonite for the synthesis of dihydropyrano[c]chromenes.•Surfactant modified bentonite presented the highest catalytic activity.•The surfactant modified bentonite was stable in continuous experiments.•The recovered catalyst was reused for five cycles without loss of its activities.•A complete catalytic mechanism is proposed.

CTMAB-bentonite was found to be an efficient catalyst for the synthesis of 3,4-dihydropyrano[c]chromene derivatives by one-pot reaction of 4-hydroxycoumarin, aromatic aldehydes, and malononitrile in aqueous ethanol under mild condition. High yields, short reaction time, easy work-up, eco-friendly, non-toxic and reusable catalyst are the advantages of this procedure.

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