Micellar Liquid Chromatographic Green-Enantioseparation of Racemic Amino Alcohols and Determination of Elution Order.

A micellar liquid chromatographic method is proposed for the green enantioseparation of racemic amino alcohols in which aqueous solution of the mixed surfactants is used as the alternative of organic solvents. In this work, the derivatives of the amino alcohols were synthesized using highly reactive chiral esters of (S)-levofloxacin under microwave conditions, and the aqueous solution of surfactant (Brij-35 and SDS) was used enantioseparation of synthesized diastereomeric derivatives of amino alcohols on RP-HPLC. The activated ester of (S)-levofloxacin was synthesized by reacting with N-hydroxybenzotriazole, and characterized by UV, IR, 1 HNMR, HRMS, and elemental analysis. The diastereomeric derivatives of racemic amino alcohols were separated on C18 column by micellar liquid chromatography. Chromatographic conditions were optimized by varying concentration of surfactant in aqueous solution, and by varying concentration and pH of the buffer. The green assessment score was calculated for developed method (82 score, an excellent green method). In addition, the density functional theory calculations were performed in order to develop lowest energy optimized structures of diastereomeric derivatives. The method was validated according to ICH guidelines and the retention factor (k), selectivity factor (α), resolution factor (RS ), and limit of detection (0.198 ng mL-1 or 0.291 pM mL-1 ) and limit of quantification (0.594 ng mL-1 or 0.873 pM mL-1 ) were calculated.