Sulfonic acid-functionalized MIL-101(Cr) as a highly efficient heterogeneous catalyst for one-pot synthesis of 2-amino-4H-chromenes in aqueous medium

Abstract

Sulfonic acid-functionalized MIL-101(Cr) was established to be an active heterogeneous catalyst for the one-pot synthesis of 2-amino-4H-chromenes via a three-component condensation reaction between resorcinol, malononitrile and a diverse range of aromatic aldehydes in aqueous medium. Here, sulfonation of the parent MIL-101(Cr) has been carried out through a post synthetic modification (PSM) technique. The resulting MIL-101(Cr)–SO₃H has been characterized by employing powder X-ray diffraction, N₂ sorption, FESEM, EDS, FT-IR and TGA studies. Furthermore, the catalyst can easily be recovered and recycled without much change in catalytic activity.