A convenient total synthesis of indolo[2,3‐b]carbazole‐6,12‐dione

Abstract Indolo[2,3‐b]carbazole‐6,12‐dione is exceptionally attractive due to its efficient antitumor activity. Synthesis of biologically potent symmetric indolo[2,3‐b]carbazole‐6,12‐dione and its N‐ alkylated derivatives has been achieved by exploring the keto group of easily accessible 2,3,4,9‐tetrahydro‐1 H ‐carbazol‐1‐one with remarkable yields just in five steps, utilizing the two classical reactions—Japp‐Klingemann procedure followed by Fischer Indole Cyclisation as key steps. The required formylation of N ‐alkylated 2,3,4,9‐tetrahydro‐1 H ‐carbazol‐1‐one has been effectively accomplished through Cross Claisen Condensation.