96631-91-3Relevant academic research and scientific papers
Microwave assisted Leimgruber-Batcho reaction for the preparation of indoles, azaindoles and pyrroylquinolines
Siu, Jason,Baxendale, Ian R.,Ley, Steven V.
, p. 160 - 167 (2007/10/03)
The development of enhanced conditions for Lewis acid catalysed Leimgruber-Batcho indole synthesis using microwave acceleration is described. This approach has permitted the preparation of a variety of heteroaromatic enamine intermediates in good yield and high purities. Subsequent catalytic hydrogenation reactions, under various conditions including the use of a solid-phase encapsulated catalyst, furnish the corresponding indole derivatives in good yields.
SYNTHESIS OF 4-SUBSTITUTED INDOLES FROM o-NITROTOLUENES
Kruse, Lawrence I.
, p. 1119 - 1124 (2007/10/02)
A facile two- or three-step transformation of o-nitrotoluenes into 4-substituted indoles is described.Treatment of o-nitrotoluenes 1 with DMF acetal, or sometimes more advantageously with tris(N,N-dimethylamino)methane, affords β-(N,N-dimethylamino)styrenes 2 which are readily converted too-nitrophenylacetaldehyde semicarbazones 3 without isolation.Reduction of either 2 or 3 affords 4-substituted indoles 4.Use of the very insoluble semicarbazones results in vastly superior yields of 4 by minimizing completing bimolecular condensation reactions during reduction.This new procedure has been applied to efficiently and conveniently prepare a series of 4-substituted indoles 4.
