Synthesis of pyrrolo[3′,4′:2,3]azepino[4,5,6-cd]indole-8,10-diones

3-Amino-4-(3-indolyl)pyrrolin-2,5-diones are condensed with various aldehydes and ketones to the cor responding imines. Under Pictet-Spengler conditions, the latter do not cyclize to pyrrolo-β-carbolines, but readily yield pyrrolo[3′,4′:2,3]azepino[4,5,6-cd]indole-8,10-diones.