Purification of Partially Resolved Enantiomeric Mixtures with the Guidance of Ternary Phase Diagram

The rationale and strategy for purification of partially resolved enantiomeric mixtures based on ternary phase diagrams are discussed. From the ternary phase diagram, one can deduce if a feasible process can be developed to upgrade the enantiomeric excess (ee) of a partially resolved enantiomeric mixture. When such a process is determined to be feasible, the optimal conditions can then be defined based on the ternary phase diagram to upgrade ee to a desirable value with maximum yield. Three ee upgrade examples of pharmaceutical processes are presented to demonstrate the importance and success of application of ternary phase diagrams in designing an optimal process.