Racemic Structure and Optical Resolution by Preferential Crystallization of DL-Cysteine Salts of Substituted Benzenesulfonic Acids
作者:Tadashi Shiraiwa、Hirohide Tazoh、Michio Sunami、Yujin Sado、Hidemoto Kurokawa
DOI:10.1246/bcsj.60.3985
日期:1987.11
Infrared absorption spectrum, solubility, and thermodynamic analysis indicated that DL-cysteine salts of benzenesulfonic acid (DL-BA salt) and 4-ethylbenzenesulfonic acid (DL-4-EB salt) are conglomerates at room temperature, but DL-BA salt forms a racemic compound at the melting point. These DL-salts were optically resolved by the preferential crystallization. As for DL-4-EB salt, suitable conditions were
红外吸收光谱、溶解度和热力学分析表明,苯磺酸的 DL-半胱氨酸盐(DL-BA 盐)和 4-乙基苯磺酸(DL-4-EB 盐)在室温下是聚集体,但 DL-BA 盐形成了熔点时的外消旋化合物。这些DL-盐通过优先结晶被光学拆分。对于 DL-4-EB 盐,通过过饱和溶液中临界成核的自由能来估计合适的条件。发现在 20 °C 的乙醇中连续优先结晶得到 D-和 L-4-EB 盐,光学纯度为 97-100%,分辨率为 83-90%。纯化并随后用三乙胺处理得到光学纯的 D-Cys 和 L-Cys。