Preparative enantiomer separation of dichlorprop with a cinchona-derived chiral selector employing centrifugal partition chromatography and high-performance liquid chromatography:: A comparative study
Preparative enantiomer separation of dichlorprop with a cinchona-derived chiral selector employing centrifugal partition chromatography and high-performance liquid chromatography:: A comparative study
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DOI：
10.1021/ac040102y
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发表时间：
2004-10-01
影响因子：
7.4
通讯作者：
Lindner, W
中科院分区：
文献类型：
--
作者：
Gavioli, E;Maier, NM;Lindner, W
利用一种由双-1,4-（二氢喹啉基）酞嗪衍生的高对映选择性手性固定相添加剂（CSPA），建立了一种逆流色谱分离除草剂2-（2,4-二氯苯氧基）丙酸（二氯丙）的无载体制备对映体分离方法。在液液萃取实验的指导下，确定了10 mM甲基叔丁基醚CSPA和100 mM磷酸钠缓冲液（pH 8.0）组成的溶剂体系为合适的固定/流动相组合。宜必思溶剂体系在固定相保留、对映体选择性和平衡的分析物分布行为之间提供了理想的折衷。使用商用离心分配色谱仪，可以实现高达366 mg外消旋二氯丙的完全对映体分离，对应于相当于所使用CSPA摩尔量的样品负载。CPC方案的制备性能特征与使用二氧化硅负载的双-1,4-（二氢喹啉基）酞嗪手性固定相CSP的高效液相色谱分离的制备性能进行了比较，结果表明两种技术的负载能力相当，但CPC的溶剂消耗明显更低。在生产率方面，HPLC被发现是优越的，主要是由于CPC仪器固有的流量限制。鉴于专用的高对映体选择性cspa的仪器设计和工程可以取得进一步的进展，CPC可能为基于csp的HPLC分离制备规模对映体提供可行的替代方案。
A countercurrent chromatography protocol for support-free preparative enantiomer separation of the herbicidal agent 2-(2,4-dichlorphenoxy)propionic acid (dichlorprop) was developed utilizing a purposefully designed, highly enantioselective chiral stationary-phase additive (CSPA) derived from bis-1,4-(dihydroquinidinyl)phthalazine. Guided by liquid-liquid extraction experiments, a solvent system consisting of 10 mM CSPA in methyl tert-butyl ether and 100 mM sodium phosphate buffer (pH 8.0) was identified as a suitable stationary/mobile-phase combination. Ibis solvent system provided an ideal compromise among stationary-phase retention, enantioselectivity, and well-balanced analyte distribution behavior. Using a commercial centrifugal partition chromatography instrument, complete enantiomer separations of up to 366 mg of racemic dichlorprop could be achieved, corresponding to a sample load being equivalent to the molar amount of CSPA employed. Comparison of the preparative performance characteristics of the CPC protocol with that of a HPLC separation using a silica-supported bis-1,4-(dihydroquinidinyl)phthalazine chiral stationary phase CSP revealed comparable loading capacities for both techniques but a significantly lower solvent consumption for CPC. With respect to productivity, HPLC was found to be superior, mainly due to inherent flow rate restrictions of the CPC instrument. Given that further progress in instrumental design and engineering of dedicated, highly enantioselective CSPAs can be achieved, CPC may offer a viable alternative to CSP-based HPLC for preparative-scale enantiomer separation.