A novel multi-component reaction of indole, formaldehyde, and tertiary aromatic amines

A novel multi-component reaction of indoles, formaldehydes, and tertiary aromatic amines is described for the synthesis of dialkylaminoarylated indoles using silica-supported perchloric acid (HClO4-SiO2) as an inexpensive and highly efficient catalyst. The key features of this multi-component reactions are operational simplicity, mild reaction conditions, regioselectivity, and recycling of catalyst.