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 ...