Solvent-free synthesis of aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes using silica sulfuric acid as catalyst

A simple and efficient method for the synthesis of aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes using silica sulfuric acid as a reusable eco-friendly catalyst under solvent-free conditions is described.