PEG–SO3H catalyzed, environmentally benign synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes under solvent-free conditions

Abstract

A highly efficient, eco-friendly and high yielding procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes has been developed through one-pot condensation reaction of β-naphthol with various aromatic aldehydes in the presence of a catalytic amount of sulfonated polyethylene glycol 6000 (PEG–SO₃H) as a stable, recyclable and bio-degradable polymeric catalyst under solvent-free conditions. This protocol was found to be applicable to obtain a diverse range of dibenzoxanthene derivatives in 82–98% isolated yields and the catalyst was recycled for four cycles.