3H-indolium salts efficiently prepared from N-substituted anilines and α-branched ketones by an one-pot synthesis

✍ Scribed by Thomas Zimmermann; Ortwin Brede

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2004
• Tongue: English
• Weight: 361 KB
• Volume: 41
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570410117

✦ Synopsis

Abstract

Starting with the N‐substituted anilines 4/12 and the α‐branched ketones 3 the 3__H__‐indolium salts 1 and their fused derivatives 13 are prepared by combining a sodium nitrite nitrosation, a zinc dust reduction, a hydrazone formation and a Fischer indolization to a reaction sequence in which the isolation and purification of intermediates is not necessary. The scope and limitations of this effective one‐pot synthesis are discussed.