OICC Press Iranian Journal of Catalysis 2345-4865 8 4 2024 02 03 Employing a hydrophobic-bentonite as a highly efficient and versatile catalyst for a green one-pot and rapid synthesis of 4H-benzo-[b]-pyran derivatives EN Mohammad Ebrahim Sedaghat Department of Chemistry, Lamerd Branch, Islamic Azad University, Lamerd, Iran. Faranak Farhadi Department of Chemistry, Lamerd Branch, Islamic Azad University, Lamerd, Iran. Mohammad Reza Nazarifar Department of Chemistry, Lamerd Branch, Islamic Azad University, Lamerd, Iran. Rezvan Sheikhi Kamareji Department of Chemistry, Lamerd Branch, Islamic Azad University, Lamerd, Iran. Journal Article 2024 02 03 A hydrophobic-bentonite catalyst (cetyltrimethyl ammonium bromide-bentonite) has been used as a very mild, neutral, eco-friendly, reusable, non-toxic, low-cost and easily available catalyst. It was prepared by replacing the exchangeable Na+ cations of a homoionic Na–bentonite with cetyltrimethyl ammonium bromide (CTMAB) cations. The catalyst was characterized by XRD, BET and SEM. The BET data and XRD patterns showed that the surfactant ions enter the interlayer space of catalyst. In order to study the catalytic properties, we carried out a one-pot practical, efficient and green multicomponent synthesis of 4H-benzo-[b]-pyran derivatives in terms of high yield, simple experimental procedure, low reaction time and simple work-up.