Synthesis and crystal structure of a bench-stable pyridinium ketene hemiaminal: 1-(1-ethoxyethenyl)-2-[methyl(phenyl)amino]pyridin-1-ium trifluoromethanesulfonate

The novel bench-stable N-quaternized ketene N,O-acetal, C16H19N2O+ · CF3O3S − , was synthesized and its structure determined. The title compound is a rare example of a pyridinium ketene hemiaminal for which a crystal structure has been determined, joining the 2-chloro-1-(1-ethyoxyethenyl)pyridin-1-ium trifluoromethanesulfonate salt from which it was synthesized. The cationic species of the title compound can be defined by three individually planar fragments assembling into a non-coplanar cation. The phenyl substituent extending from the amino nitrogen atom and the ethyoxyvinyl substituent extending from the pyridine N atom are oriented on the same side of the molecule and maintain the closest coplanar relationship of the three fragments. Supramolecular interactions are dominated by C — H...O interactions from the cation to the SO3 side of the trifluoromethanesulfonate anion, forming a two-dimensional substructure.
Source: Acta Crystallographica Section E - Category: Chemistry Authors: Tags: crystal structure ketene hemiaminal N-quaternized ketene N,O-acetal research communications Source Type: research