characterization and application of so3h-functionalized phthalimide (sfp) as an efficient and recyclable catalyst for the solvent-free synthesis of 2-amino-4h-chromenes

in this research, so3h-functionalizedphthalimide (sfp) has been prepared through simple reaction of phthalimide with chlorosulfonic acid, and characterized using ft-ir, 1h nmr, 13c nmr, sem (scanning electron microscopy), mass and tg (thermal gravimetric) spectra. afterward, the solid acid has been utilized as an efficient, green, heterogeneous and recyclable catalyst for the solvent-free synthesis of 2-amino-4h-chromenes by the one-pot multi-component reaction of aromatic aldehydes with malononitrile and 1-naphthol under thermal (70 °c) and microwave (540 w) conditions.