Synthesis and high‐resolution ¹H NMR spectra of four dimethylaminated dipyridyl ketones

Abstract

Four new dimethylaminated pyridoylpyridine intermediates, bis(3-dimethylamino-2-pyridyl) ketone (l), 6-dimethylamino-3-pyridyl epyridyl ketone (2), 6-dmethylamino-3-pyridyl 3-pyridyl ketone (3) and 6-dimethylamino-3-pyridyl 2-pyridyl ketone (4), have been synthesized and their lOOMHz 'H NMR spectra analysed iteratively as ABC, ABCX and ABXY spin systems. In 2-4 the H-5 shift ortho to the dimethylamino substituent is unaffected by the orientation of the pyridyl substituent, but H-4 and H-2 are increasingly deshielded in the sequence 2-4. In 3, when benzene-d6 replaces chloroform-d, as solvent, H-5' and H-4' in the umubstituted pyridyl ring suffer appreciable upfield shifts.