Sonication and aluminum amalgam in the leimgruber-batcho reaction. An improved preparation of 6-aminoindole

FD Toste, IWJ Still

Index: Toste, F. Dean; Still, I. W. J. Organic Preparations and Procedures International, 1995 , vol. 27, # 5 p. 576 - 579

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Citation Number: 10

Abstract

Since its introduction some 20 years ago, the Leimgruber-Batcho indole synthesis has enjoyed great success in the preparation of ring A substituted indoles.'. 2 In general, the reaction involves condensation of the appropriate o-nitrotoluene 1 with dimethylformamide dimethyl acetal (DMFDMA) to afford the anticipated P-dimethylamino-2-nitrostyrene 2. Conversion of the intermediate nitroenamine into the indole 3 requires selective reduction ...