Synthesis of Dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraone using p-Toluenesulfonic Acid as Catalyst

Abstract

This methodology involves synthesis of dibenzo xanthene tetraone by one pot multicomponent reaction of 2-hydroxy-1,4-naphthoquinone and pyrazole aldehyde in presence of p-toluenesulfonic acid (PTSA) as catalyst in ethylene glycol at 75-95 ºC. This protocol provides excellent yields (80-90%) involving simple workup procedures and purification techniques. By using several spectroscopic techniques the compounds were characterized.