[Potential cardiotonics. 16. Molecular and crystal structures of three polymorphic forms and a hydrochloride monohydrate of 3-cyano-2-morpholino-5-(pyridin-4-yl)pyridine (AWD 122-14)].

The results of an X-ray structure analysis of the alpha-modification were the starting point for the prediction and establishment of further polymorphic and pseudopolymorphic, respectively, forms of AWD 122-14. A complete structure determination of the gamma- and delta-modifikation as well as of a hydrochloride monohydrate could be carried out. Molecular parameters, conformational flexibility, and intermolecular interactions are discussed in this paper.