Intramolecular addition of acyldiazenecarboxylates onto double bonds in the synthesis of heterocycles

José V. Prata, Dina Telma V. Clemente, Alberto Sundaresan Prabhakar, Ana Maria Félix Trindade Lobo, Isabel Mourato, Paula Cristina de Sério Branco

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

Appropriate aryl-substituted unsymmetrical azodicarbonyl compounds, generated from bishydrazides by oxidation, undergo intramolecular cyclisations to furnish a variety of useful heterocycles such as N-substituted oxindoles, carbostyrils, benzazepinones, benzazocinones, benzimidazolones, benzoxazinones and pyrazolones in varying degrees of efficiency. Methods are described to remove the N-acyl groups from the heteroaromatic compounds. Under mildly acidic conditions where equal opportunities are available for an ipso or a normal cyclisation it is the former process that occurs preferentially. Evidence is presented in favour of a C-to-C migration in the ipso product for the formation of a methoxy-substituted carbostyril derivative. One of the spiro substances is shown to participate in dienone-phenol rearrangement to provide the corresponding quinolone-phenol in high yield.
Original languageEnglish
Pages (from-to)513-528
Number of pages16
JournalJournal Of The Chemical Society-Perkin Transactions 1
VolumeNA
Issue number4
DOIs
Publication statusPublished - 1 Jan 2002

Keywords

  • Substitution reactions
  • Synthesis (chemical)
  • Addition reactions
  • Chemical bonds
  • Derivatives
  • Oxidation

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