A concise and efficient synthesis of seco-duocarmycin SA

A short and efficient synthesis of seco-duocarmycin SA (3), a highly potent cytostatic agent and direct precursor of the natural product duocarmycin SA (1), has been achieved. Starting from commercially available 2-methoxy-4-nitroaniline (4) the synthetic protocol contains a Fischer indole synthesis to introduce the heterocyclic scaffold and a radical 5-exo-trig cyclization to furnish the (chloromethyl)indoline ring system as key reactions. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).