An efficient synthesis of symmetrical 2,2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one is achieved via a reaction of acenaphthe-nequinone and indoles catalyzed by solid superacid SO_4~(2-)/TiO_2 under solvent-free conditions at room temperature by grinding, which provides an efficient route to the synthesis of symmetrical 2,2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one.This procedure offers several advantages including solvent-free conditions,excellent yields of products,simple work-up as well as reuse of catalysts which makes it a useful and attractive protocol for the synthesis of these compounds. An efficient synthesis of symmetrical 2,2-bis (1H-indol-3-yl) -2H-acenaphthen-1-one was achieved via a reaction of acenaphthe-nequinone and indoles catalyzed by solid superacid SO 4 2- under solvent-free conditions at room temperature by grinding, which provides an efficient route to the synthesis of symmetrical 2,2-bis (1H-indol-3-yl) -2H-acenaphthen-1-one. solvent-free conditions, excellent yields of products, simple work-up as well as reuse of catalysts which makes it a useful and attractive protocol for the synthesis of these compounds.