New Synthetic Approach for the Preparation of Imidazole N3-Oxide

Hugo Cerecetto; Alejandra Gerpe; Mercedes González; Yolanda Fernández Sainz; Oscar E. Piro; Eduardo E. Castellano

doi:10.1055/s-2004-831212

PAPER

New Synthetic Approach for the Preparation of Imidazole N ³-Oxide

Hugo Cerecetto*^a, Alejandra Gerpe^a, Mercedes González*^a, Yolanda Fernández Sainz^b, Oscar E. Piro^c, Eduardo E. Castellano^d
^a Department of Organic Chemistry, Faculty of Chemistry/Faculty of Sciences, University of the Republic, 11400 Montevideo, Uruguay
Fax: +598(2)5250749; e-Mail: hcerecet@fq.edu.uy; e-Mail: megonzal@fq.edu.uy;
^b Facultad de Ciencias, Pz/Misael Bañuelos s/n, Universidad de Burgos, Burgos, Spain
^c Department of Physic, University National of La Plata, 1900 La Plata, Argentina
^d Institute of Physics, University of São Paulo, 13560 São Carlos, Brazil

Abstract

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Abstract

A new synthetic procedure of 1-alkyl(aryl)-1H-4-methylimidazole N ³-oxide derivatives by cyclocondensation of α-amineoximes and orthoesters was studied. Low yields in the cyclization process were the result of predominant Z-stereoisomer around the oxime moiety of α-amineoxime reactants. Different attempts to improve these yields were assayed, mild conditions being those that produce the best results. Also, the special acidity of hydrogen-2 in the imidazole N ³-oxide system was studied in solution by NMR spectroscopy. This property provides a convenient intermediate to access 2-substituted analogues.

Keywords

imidazole N-oxide - cyclization - H-2 acidity

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References

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New Synthetic Approach for the Preparation of Imidazole N 3-Oxide

New Synthetic Approach for the Preparation of Imidazole N ³-Oxide