Synthesis of Annulated Carbazoles from Indol-2,3-dione
Reaction of ethyl chloroformate with 3-aroylmethylindol-2(3H)-ones 5 affords the ethyl 3--2-(ethoxycarbonyloxy)indole-1-carboxylates 6 from which the corresponding annulated carbazoles 10 are obtained via 6?-electro