Phosphosulfonic acid, an efficient solid acid catalyst for the one-pot preparation of 14-aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes under solvent-free conditions

摘要

An expeditious procedure for the synthesis of 14- aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes through one-pot pseudo three component condensation of β-naphthol or dimedone with various aryl aldehydes is described. This greener protocol is catalyzed by phosphosulfonic acid, and proceeds efficiently in the absence of any organic solvent under optimized, mild, green and environmentally benign reaction conditions in high yields within 20-55 minutes.