LARGE-SCALE ENANTIOMERIC ENRICHMENT VIA SOLID-STATE EXTRACTION USING BETA-CYCLODEXTRIN CRYSTALLINE AND ANHYDROUS ACETONITRILE AS SOLID AND LIQUID-PHASES

The process-scale enantiomeric enrichment of several adrenergic beta-b lockers, atropine, and ruelene was accomplished through solid state ex traction using anhydrous acetonitrile and beta-cyclodextrin crystallin e as liquid and solid phases, respectively. This non-chromatographic m ethod has the advantages of easy, low cost operation, simplicity, and a high percentage of enrichment for some of the beta-blockers examined in a single batch. The percentage of enrichment in anhydrous acetonit rile was the best for all the racemates studied; however, it dropped d ramatically when the extraction was carried out in a liquid phase of l ow polarity such as petroleum ether. No enantiomeric enrichment was ob served in liquid phases that are polar and capable of participating in hydrogen bonding (e.g., methanol). Introducing additives (e.g., aceti c acid, triethylamine) to the liquid phase also decreased the percenta ge of enrichment. Finally, lowering the operating temperature (0 degre es C) appeared to retard the enantiomeric extraction process, which co uld be restored to normal level by elevating liquid phase temperature to 28 degrees C.