o-Styrylnitrene route to 2-substituted indoles. Pyrolysis of o-azidostyrenes

RJ Sundberg, HF Russell, WV Ligon Jr…

Index: Sundberg,R.J. et al. Journal of Organic Chemistry, 1972 , vol. 37, p. 719 - 724

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Citation Number: 39

Abstract

The utility of o-azidostyrene derivatives as indole precursors via o-styrylnitrenes has been examined. The cyclization proceeds efficiently for@-alkyl-and@-aryl-o-azidostyrenes and is also satisfactory for p-acyl-o-azidostyrenes. A synthesis of 2-acylindoles involving two steps, base-catalyzed condensation of a methyl ketone with o-azidobenzaldehyde and pyrolysis to the indole, was carried out successfully in five cases with yields from 21 to 7301,. These ...