Molecules (Apr 2023)

A Two-Step Synthesis of Unprotected 3-Aminoindoles via Post Functionalization with Nitrostyrene

  • Nicolai A. Aksenov,
  • Nikolai A. Arutiunov,
  • Igor A. Kurenkov,
  • Vladimir V. Malyuga,
  • Dmitrii A. Aksenov,
  • Daria S. Momotova,
  • Anna M. Zatsepilina,
  • Elizaveta A. Chukanova,
  • Alexander V. Leontiev,
  • Alexander V. Aksenov

DOI
https://doi.org/10.3390/molecules28093657
Journal volume & issue
Vol. 28, no. 9
p. 3657

Abstract

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A novel, low-cost method for the preparation of not easily accessible free 3-aminoindoles has been developed. This approach is based on a well-established reaction between indoles and nitrostyrene in the presence of phosphorous acid, which results in the formation of 4′-phenyl-4′H-spiro[indole-3,5′-isoxazoles]. The latter could be transformed to corresponding aminated indoles by reaction with hydrazine hydrate in good or excellent yields upon microwave-assisted heating.

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