Basanagoudar, L D; Mahajanshetti, C S; Hendi, S B, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1991, vol. 30, # 11, p. 1014 - 1017
Fischer indolisation of 2,6-dialkyl and 2,4,6-trialkylphenylhydrazones of diketones and ketoesters
摘要:
Unlike the migration of a methyl group observed in the ZnCl2 or acetic acid-catalysed indolisation of phenylhydrazones, dry ethanolic HCl catalysed indolisation of 2,6-dimethyl- and 2,4,6-trimethylphenylhydrazones of various substituted butane-2,3-diones and ethyl pyruvates yields 7-methyl- and 5,7-dimethyl-3-substituted indoles indicating elimination of an ortho-methyl group during indolisation. (C) 2003 Elsevier Ltd. All rights reserved.
Novel method for synthesis of aryl hydrazones from α-diazo esters: scope and limitations of nucleophiles
作者:Eiko Yasui、Masao Wada、Norio Takamura
DOI:10.1016/j.tet.2008.11.028
日期:2009.1
Aryl hydrazones, the precursor of Fischer indole synthesis, were easily obtained by nucleophilic addition of aryllithium reagents to diazo esters. The aryl hydrazones were converted into indoles in good yields by heating with thionyl chloride in alcohol. Grignard reagent was also a good nucleophile, whereas organozinc reagent did not react with diazo esters. Aryllithium reagents were prepared by reacting