Design of molecularly imprinted resin material with sulfonic acid functionalization for enantioseparation of (±)‐cathine

Abstract

AbstractIn the current work, an enantioselective imprinting technique was used to develop a very selective adsorbent for the (+)‐cathine ((+)‐Cat) enantiomer. The phenolic sulfonamide produced from 2,4‐dihydroxybenzenesulfonic acid (HBS) and (+)‐Cat ((+)‐Cat‐HBS) was initially synthesized by triphenylphosphene activation and subsequently involved in condensation polymerization with resorcinol in the presence of formaldehyde under acidic conditions. Alkaline sulfonamide bond‐breaking was subsequently employed to separate the (+)‐Cat template from the polymer, and the resulting imprinted resin ((+)‐CIP) displayed high selectivity for the (+)‐Cat, with a capacity of 225 ± 2 mg/g. Studies of selectivity also showed that the (+)‐Cat enantiomer was preferred over its counterpart because of the development of configurationally matching receptors. In addition, the produced resin was used for the enantioresolution of (±)‐Cat racemate by column method, yielding a loading supernatant solution with an enantiomeric excess of (+)‐Cat 50% and a recovery eluant solution with an excess of (−)‐Cat 85%.