Cyclisation reactions of some pyridazinylimidoylketenes

Alexander P. Gaywood, Lawrence Hill, S. Haider Imam, Hamish McNab, Gabor Neumajer, William J. O'Neill, Péter Mátyus

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Flash vacuum pyrolysis (FVP) of aminopyridazinone derivatives of Meldrum's acid at 600 °C (0.02 Torr) results in generation of an imidoylketene intermediate followed by cyclisation. In the case of the 5-amino derivatives, the products are pyrido[2,3-d]pyridazines, whereas the 4-amino compounds lead to mixtures of pyrido[2,3-d]pyridazines and pyrrolo[3,2-c]pyridazines. The feasibility of the 1,5-sigmatropic shift of a chlorine atom, required for the formation of two of the pyrido[2,3-d]pyridazines, was supported by the corresponding reaction of a corresponding 2,6-dichloroaniline derivative. The feasibility of the decarboxylation mechanism required for the formation of the pyrrolo[3,2-c]pyridazines, was supported by related processes in the FVP reactions of model compounds and by DFT calculations.

Original languageEnglish
Pages (from-to)236-242
Number of pages7
JournalNew Journal of Chemistry
Issue number2
Publication statusPublished - 2010


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Materials Chemistry

Cite this

Gaywood, A. P., Hill, L., Imam, S. H., McNab, H., Neumajer, G., O'Neill, W. J., & Mátyus, P. (2010). Cyclisation reactions of some pyridazinylimidoylketenes. New Journal of Chemistry, 34(2), 236-242.