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DOI: 10.1039/A901332F (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 1, 1999, 1853-1858

Synthesis of (Z[hair space])-N-(2-amino-1,2-dicyanovinyl)formamide O-alkyloximes and a study of their cyclization in the presence of base

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Brian L. Booth, Flora A. T. Costa, Zahid Mahmood, Robin G. Pritchard and M. Fernanda Proença

Abstract

The title compounds (3) have been prepared in high yield by reaction of (Z[hair space])-N-(2-amino-1,2-dicyanovinyl)formimidate with an alkoxyamine NH2OR (R = CH2Ph, Me). These compounds cyclize to the corresponding 5-amino-4-cyanoimidazoles 4 by reaction with ethanolic NaOH solution. In ethyl acetate and using DBU as a base, amidoximes 3 follow an unexpected cyclization pathway leading to a pyrimidine structure 5. Single-crystal X-ray structures have been obtained for both the amidoxime 3a and the pyrimidine 5a (R = CH2Ph). A strong intramolecular H-bond in the amidoxime structure, which was identified both in the solid state and in solution, may be responsible for the unusual cyclization pattern observed in these compounds.

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