X-ray mapping in heterocyclic design: III. Diffractometric study of the crystal structure of 1-methyl-2-oxo-2,3-dihydroimidazo[1,2-a]pyridinium bromide

The crystal structure of 1-methyl-2-oxo-2,3-dihydroimidazo[1,2-a]pyridinium bromide C8H9BrN2O is determined by X-ray diffraction. The structure is solved by the direct method and refined by the least-squares procedure to R = 0.0599. The geometry of the pyridinium fragment observed in the molecule corresponds to the limited number of centers at which the positive charge can be delocalized. Apparently, this delocalization predominantly occurs in the NCN fragment of the imidazole ring and only slightly affects the pyridine moiety of the molecule