Straightforward Access to (Imidazol-2-yl)acetates by Reaction of 2-Unsubstituted Imidazole 3-Oxides with Dimethyl Acetylenedicarboxylate

A new method for the preparation of 1,4,5-trisubstituted (imidazol-2-yl) acetates, based on the reaction of the corresponding imidazole 3-oxides with dimethyl acetylenedicar-boxylate (DMAD) is described. Formation of the products is rationalized by a formal 1,3-dipolar cycloaddition and subsequent oxaloyl cleavage.