Co-Crystallization Induced Spontaneous Deracemization: A General Innovative Thermodynamic Approach to Deracemization.

Processes leading to enantiopure compounds are of utmost importance, in particular for the pharmaceutical industry. Starting from a racemic mixture, Crystallization Induced Diastereomeric Transformation allows for a theoretical 100% transformation of the desired enantiomer. However, this method has the inherent limiting requirement for the organic compound to form a salt. In this contribution, this limitation is lifted by introducing cocrystallization in the context of thermodynamic deracemization, with the process applied to a model chiral fungicide. We here report a new general single thermodynamic deracemization process based on co-crystallization for the deracemization of (R,S)-4,4-dimethyl1-(4-fluorophenyl)-2-(1H-1,2,4-triazol-1-yl)-Pentan-3-one. This work presents the feasibility of this novel approach and paves the way to further development of such processes.