An Efficient Synthesis of Bis-indolylindane-1,3-diones, Indan-1,3-diones, and Indene-1,3(2H)-denies Using [Hbim]BF₄ Ionic Medium

Scheme 4

Plausible mechanism for the synthesis of 2,2-bis(4-(dimethylamino)phenyl)-1H-indene-1,3(2H)-denies in the presence of [Hbim]BF₄ ionic medium.