OICC Press Iranian Journal of Catalysis 2345-4865 5 3 2024 02 03 Brønsted acidic ionic liquid as the efficient and reusable catalyst for synthesis of coumarins via Pechmann condensation under solvent-free conditions EN Abdol Reza Hajipour Pharmaceutical Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156, Islamic Republic of Iran Nafisehsadat Sheikhan Department of Chemistry, Faculty of Sciences, Najafabad Branch, Islamic Azad University, Najafabad, Esfahan, P.O. Box 517, Iran. Mohammad Ali Alaei Pharmaceutical Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156, Islamic Republic of Iran Amin Zarei Department of Science, Fasa Branch, Islamic Azad University, PO Box No. 364, Fasa 7461713591, Fars, Iran. Journal Article 2024 02 03 A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to produce the corresponding substituted coumarins in high to excellent yields and short reaction times. Moreover, [TEBSA][HSO4] has been used as an effective green catalyst for the synthesis of coumarin derivatives under solvent-free conditions. Using the relatively non-toxic (halogen-free) and reusable Brønsted acidic ionic liquid, high catalytic efficiency, high yields, short reaction times and straightforward work-up are advantages of this protocol.