The compound discovery stage for many pharmaceuticals, agrochemicals, and materials often requires the synthesis of a large number of compounds in relatively small amounts (milligram to gram scale). Although the synthesis of libraries of organic compounds can be automated, the workup of these reactions is frequently time consuming. Often a liquid-liquid extraction is followed by column chromatography.
A faster technique has been developed by Bo Xu and Gerald Hammond, Rigid Solutions, LLC, Shelbyville, KY, USA, and the University of Louisville, KY, USA. Instead of a conventional workup, a porous honeycomb-like organic polymer (Porelite) is added to the reaction mixture (≈ 3 mL/g of product). Porelite absorbs the product and the organic solvent in which it is dissolved. This high internal phase emulsion polymer contains extremely large cavities interconnected by smaller pores that allow the product in and out. The loaded polymer is then simply filtered and washed before elution of products or loading onto a chromatographic column.
In tests, excellent recovery rates were obtained for hydrocarbons, phenols, heterocycles, acids, and bases. This general technique lends itself to parallel and automated operations.
- Rapid Chemical Reaction Workup Based on a Rigid Solvent Extraction,
Bo Xu, Gerald B. Hammond,
Org. Lett. 2014.