Organic letters

Fischer indole synthesis in low melting mixtures

S Gore, S Baskaran, B König

Index: Gore, Sangram; Baskaran, Sundarababu; Koenig, Burkhard Organic Letters, 2012 , vol. 14, # 17 p. 4568 - 4571

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Citation Number: 66

Abstract

Functionalized indoles are synthezised under mild conditions in a tartaric acid–dimethylurea melt. The melt serves as the solvent and as the catalyst. Under these reaction conditions, sensitive functional groups such as N-Boc, N-Cbz, or azides are stable, and indolenines are obtained regioselectively in excellent yields. The practical use of the method is demonstrated in the synthesis of the hormone melatonin.