Resolution of Racemic Mixtures by Phase Transition of PEGylated Resolving Agents

• Published in: ACS omega Vol. 2; no. 12; pp. 8717 - 8722
• Main Authors: Mokhtari, Javad, Azarnoosh, Sahar, Karimian, Khashayar
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 31-12-2017
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.7b01070

A novel, efficient, and simple method for the resolution of racemic mixtures is presented in which PEGylated resolving agents are subjected to diastereomeric complex formation in alcohols. The resulting complexes then undergo temperature-assisted phase transition, affording a precipitate that is enriched in one enantiomer and separable by filtration. In an aqueous solution, phase transition can be caused by the methods used in the precipitation of poly­(ethylene glycol) (e.g., addition of ammonium sulfate). A number of racemic amines have been successfully resolved using this method. The first cycle of resolution affords the amines with an optical purity of 72–85% from their corresponding racemic mixture in good yields (78–90%). An additional cycle improved the optical purity to 87–95%. The PEGylated resolving agents can be recovered and reutilized without the loss of resolution efficiency.