Abstract
A simpler and greener protocol has been developed for the preparation of aryl-14H-dibenzo[a. j] xanthenes: a one-pot condensation of beta-naphthol and aryl aldehydes, in the presence of silica-supported sodium hydrogen sulfate ( NaHSO4 center dot SiO2) or tungstated zirconia ( 5% WO3/ZrO2) as heterogeneous catalysts in a solvent-free media. The present methodology offers several advantages such as excellent yields, simple procedure, short reaction times ( 2-8 h), and milder conditions.