Efficient synthesis of 9H-pyrrolo[1,2-a]indol-9-one derivatives based on active manganese dioxide promoted intramolecular cyclization

A series of 9H-pyrrolo[1,2-a]indol-9-ones have been prepared via in-situ sequential oxidation of [2-(1H-pyrrol-1-yl)phenyl]methanols promoted by active manganese dioxide. The procedure led to title compounds in good yields under mild conditions, without the need to isolate the intermediate aldehydes. (C) 2009 Elsevier Ltd. All rights reserved.