Cyclic amidines as precursors for imidazoles

Abstract

The regioselective nucleophilic reactivity of cyclic amidines is considered in the context of their reactions with 2-haloketones to generate imidazoles. Since the tautomer with an endocyclic imine is favoured, reaction with the 2-haloketone electrophile proceeds via initial alkylation at the ring nitrogen. This was confirmed by repeating a suitable literature reaction and submitting the isolated product to single-crystal X-ray analysis.