疏水性相转移手性溶剂萃取分离叔丁喘宁对映体

Chiral Solvent Extraction of Terbutaline Enantiomers by Lipophilic Phase Transfer

以四苯硼钠 (NaBPh4)为疏水性相转移试剂 ,研究了叔丁喘宁对映体分别在含 13种不同烷基链的L 酒石酸酯手性选择体水 有机溶剂两相系统中的萃取分配行为 ,考察pH和有机溶剂对分配系数 (K)和分离因子 (α)的影响。实验表明 :BPh-4与叔丁喘宁对映体阳离子形成疏水性复合盐 ,促进叔丁喘宁对映体在有机溶剂中的溶解 ,提高了分配系数 ;L 酒石酸酯与叔丁喘宁对映体Ⅱ形成非对映体复合物的稳定性比与对映体Ⅰ形成的非对映体大 ;随着L 酒石酸酯烷基链的增长 ,分配系数和立体选择性增强 ;3类溶剂的萃取性能为醇>1,2 二氯乙烷 >烷烃 ,并随着醇碳原子数的增加 ,两对映体的分配系数和分离因子增大 ;pH值的影响很大。

Distribution behavior of terbutaline enantiomers was examined in the aqueous and organic solvent of a two-phase system containing one of 13 L-tartaric acid esters and lipophilic phase transfer reagent of sodium-tetraphenylborate(NaBPh 4). The influence of pH value and organic solvents on the partition coefficients and enantioselectivity of terbutaline enantiomers was investigated. BPh- 4 lipopilic anion and terbutaline enantiomers formed two lipophilic salt complexes ,which facilitated the solubility of the enantiomers in the organic phase. The L-tartaric acid esters studied in all form are more stable complexes with enantiomerⅡthan with enantiomerⅠ.The extraction performance for the three kinds of organic solvents is different, for example, alcohols>1,2-dichloroethane>heptane, and the partition coefficients and enantioselectivity increase with addition of length of alkyl chain of L-tartrates. pH value also influence them obviously.