Enantioseparation of L-mandelic acid by diastereomeric crystallization with L-phenylalanine

摘要

In order to resolve a chiral isomer from racemic compound, diastereomeric crystallization is one of the most prospective ways in respect of production efficiency and cost effectiveness1. However, the mechanism of the resolving agent forming the diastereomeric compound selectively with a chiral isomer in racemic solution and crystallization of the diastereomeric crystal has been rarely clarified. Since optical resolutions usually depend on many correlated parameters, investigations at the molecular level might be helpful in laboratory and pilot scale optimization and may promote the development of an effective industrial scale process. Finding the best resolving agent and optimal conditions is a challenging task, which is still largely based on trial-and-error. Structural data obtained by the systematic study of diastereomeric salt formations are useful for the rationalisation of optical resolution and help in the experimental design of the most important parameters 2.