Preparation, characterization and the use of sulfonic acid-functionalized phthalimide (SFP) as a highly efficient and green catalyst for the condensation of arylaldehydes with 2-naphthol

Phthalimide was reacted with chlorosulfonic acid to give sulfonic acidfunctionalized phthalimide (SFP), which characterized by 1H NMR, 13C NMR, FTIR, XRD (Xray diffraction), SEM (scanning electron microscopy), EDX (energydispersive Xray), mass and DTG (derivative thermal gravimetry) spectra. Afterward, its catalytic activity was examined for the condensation of arylaldehydes with 2naphthol under solventfree conditions to afford 14aryl14Hdibenzo[a,j]xanthenes. The results showed that SFP was highly efficient catalyst to promote the reaction.