Silica supported sodium hydrogen sulfate (NaHSO4/SiO2): A mild and efficient reusable catalyst for the synthesis of aryl-14-H-dibenzo [a,j]xanthenes under solvent-free conditions

A simple and efficient procedure for the preparation of aryl-14-H-dibenzo [a,j]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate (NaHSO4/SiO2) as a catalyst and in the absence of solvent has been developed. The present method offers several advantages such as excellent yields, short reaction time (10–30 min), mild condition, simple work-up, and the use of a cheap and environmentally friendly catalyst with remarkable reusability.