Preferential crystallization is a resolution without use of a resolving agent. The compound to be resolved must be a conglomerate, which means it crystallizes as enantiomeric crystals.
Major pharmaceutical companies have recently emphasized the necessity to be able to determine rapidly and accurately the crystal type of a racemate, ie conglomerate, racemic compound or solid solution, and to construct and analyze the phase diagrams to obtain optimal resolutions. Syncom can do this.
From careful study of the ternary phase diagram prepared by Syncom protocols for conglomerates can be developed based on selective seeding that allow isolation of both enantiomers in high enantiomeric purity and near the theoretical yield of 50%. Syncom has extensive experience with multi-kilo production of conglomerates using the entrainment process.
For the case of organics that crystallize as racemic compounds (the majority of organic compounds) careful analysis of the phase diagram also allows on occasion discovery of metastable conglomerates than can be subjected to entrainment. Very recently in cooperation with DSM and the University of Nijmegen Syncom has participated in the development of a new method for total resolution (100% yield and 100% ee) based on Ostwald ripening induced by grinding of solids under conditions that racemization can take place in a liquid phase.
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