酒石酸和氰基二苯基二氢吡唑的高效液相色谱手性分离

Resolution of Enantiomers of Racemic 5-Cyano-4,5-dihydro-1,3-diphenylpyrazole and Tartaric Acid by High-Performance Liquid Chromatography

以不同配比的甲醇和水作洗脱液,对手性物质酒石酸和5-氰基-1,3-二苯基-4,5-二氢吡唑进行了手性色谱柱高效液相色谱分离。对于亲水性的酒石酸,以纯水作为洗脱液,手性异构体不能得到分离;洗脱液中甲醇的含量增加到50%,D-和L-异构体得到分离,但是内消旋异构体和D-异构体仍然混在一个峰中;以100%甲醇作洗脱液,酒石酸的内消旋及D-和L-三个异构体的色谱峰全部分开。对于憎水性的5-氰基-1,3-二苯基-4,5-二氢吡唑,以100%甲醇作为洗脱液;当洗脱液中水的含量增加到30%时,R-和S-手性异构体的色谱峰开始分离,但是两个峰大小不相等,分离效果不理想;当洗脱液中水的含量增加到35%时,R-和S-手性异构体的色谱峰分离为两个大致相等的色谱峰,但是两个色谱峰仍有部分交叠。保留时间加长,有利于对映异构体的分离,保留时间长的色谱峰变宽。

Enantiomer resolutions of tartaric acid and racemic 5-cyano-4,5-dihydro-1,3-diphenylpyrazole were investigated by high-performance liquid chiral chromatography using methanol and water as mobile phase. The enantiomers could not be resolved by pure water as elution solvent for tartaric acid. The resolusion of the enantiomers increased as the quantity of methanol increased in the elution solvent. The D-and L-isomers of tartaric acid were separated as the content of methanol in the elution solvent increased to 50% by volume. But the D- and meso-isomers were still merged together in one peak. The D-, L- and meso-isomers of tartaric acid were separated when pure methanol was used as elution solvent. For hydrophobic 5-cyano-4,5-dihydro-1,3-diphenylpyrazole, the enantiomers could not be resolved by pure methanol. As the quantity of water increased in the elution solvent, the enantiomer resolution and the retention time increased. The R- and S-isomers of 5-cyano-4,5-dihydro-1,3-diphenylpyrazole were separated when the quantity of water in the elution increased to 30% by volume. But the two peaks were not equal in height, showing that the separation was not perfect. The peaks of R- and S-isomers were of equal height but still overlapped to some extent as the quantity of water in the elution increased to 35% by volume. The resolution became better and the peak became broadened as the retention time became longer.