Phase diagrams of diastereomeric pairs in inclusion resolution

In the development and understanding of the resolution of diastereomeric salts, phase diagrams are of great importance. This study constitutes the first example of phase diagrams of diastereomeric complexes formed from simple chiral compounds, as used in inclusion resolutions. Simple melting diagrams and DSC thermograms could not be used, because of the decomposition of the complex caused by the escape of the guest from the inclusion complex upon heating. A ternary solution phase diagram was constructed from the diastereomeric inclusion complexes of phenethylamine with a taddol. Solid solution behavior was found and confirmed by powder diffraction and X-ray studies. The limited scope of inclusion resolutions, as already indicated by our earlier studies, was confirmed by these results.