New Synthetic Approach for Imidazole N3-Oxide

H. CERECETTO; A. GERPE; M. GONZÁLEZ; Y. FERNÁNDEZ SAINZ; O. E. PIRO; E. E. CASTELLANO

SYNTHESIS

Verlag

Año: 2004 vol. 16 p. 2678 - 2684

1414-915X

A new synthetic procedure of 1-alkyl(aryl)-1H-4-methylimidazole N3-oxide derivatives by cyclocondensation of a-amineoximes and orthoesters was studied. Low yield in cyclization process were the result of predominant Z-stereo form, around the oxime moiety, of a-amineoxime reactants. Different attempts to improve the yields were assayed, being mild conditions that produce the best results. Also, the special acidity of hydrogen-2 of imidazole N3-oxide system was studied in solution by NMR spectroscopy. This property provides a convenient intermediate to access to 2-substituted analogues.