Synthesis of 4-substituted 3-(indol-3-yl)maleimides and azepines with annelated indole and maleimide nuclei

A series of 4-substituted 3-(indole-3-yl)maleimides has been synthesized. Upon the action of CH3SO3H in TFA, the 3-(indole-3-yl)-4-(arylalkylamino)-maleimides undergo cyclization to give 12b,13-dihydro-4bH-indolo[3,2-d]pyrrolo[3,4-b][1]benzazepine-5,7(6H,8H)-dione derivatives.