SILICA SUPPORTED PERCHLORIC ACID: AN EFFICIENT AND RECYCLABLE CATALYST FOR SYNTHESIS OF BENZIMIDAZOLO[2,3-b]QUINAZOLINONES

Synthesis of benzimidazolo[2,3- b ]quinazolinone derivatives has been reported in excellent yields by using silica-supported perchloric acid (HClO 4 -SiO 2 ) as a mild and reusable heterogeneous catalyst. The procedure is simple, environmentally benign and has the advantage of high atom economy. Furthermore, the catalyst can be recovered and reused several times efficiently without substantial loss of catalytic activity.