Symmetric and asymmetric separations of propranolol (PN) enantiomers were performed by fractional extraction with boric acid (BA) and dicyclohexyl d-tartrate (DT) as the selector. A phase equilibrium model was constructed on the basis of an interfacial reaction mechanism and verified to be dependable by experiment. On the basis of the phase equilibrium model and mass conservation, a multistage model was developed to optimize the process parameters. Optimal situations for symmetric separation were obtained, involving C_PN = 0.0078 mol/L, C_DT = C_BA = 0.05 mol/L, F/W = 0.4, and O/W = 0.9435 with feeding at the center stage at pH 6.00. Under the optimal conditions, the ee_eq and Y_eq reached 0.98 and 0.99, respectively, by symmetric separation using 25 centrifugal contactor separators. Because (S)-propranolol (S-PN) is the desired enantiomer, the ee_raffinate for S-PN can be up to 0.98 with 10 stages by asymmetric separation under the situations containing C_PN = 0.0078 mol/L, C_DT = C_BA = 0.1 mol/L, F/W = 0.15, and O/W = 0.3534 with feeding at stage 3 at pH 6.00. The study shows that the required number of extraction stages is greatly decreased for high ee of S-PN by asymmetric separation.

中文翻译：

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通过分步萃取法连续分离普萘洛尔：对称分离和不对称分离

普萘洛尔（PN）对映异构体的对称和不对称分离通过硼酸（BA）和d-酒石酸二环己基酯（DT）作为选择剂的分步萃取进行。在界面反应机理的基础上建立了相平衡模型，并通过实验证明其是可靠的。在相平衡模型和质量守恒的基础上，开发了一个多阶段模型来优化工艺参数。获得了对称分离的最佳情况，包括C _PN = 0.0078 mol / L，C _DT = C _BA = 0.05 mol / L，F / W = 0.4和O / W＝ 0.9435，在中心阶段在pH 6.00下进料。在最佳条件下，通过使用25个离心接触器分离器进行对称分离，ee _eq和Y _eq分别达到0.98和0.99。因为（S）-普萘洛尔（S-PN）是所需的对映异构体，所以在C _PN = 0.0078 mol / L，C _DT = C的情况下，通过不对称分离，S-PN的ee提_余液可以通过10个阶段进行分离，最高可达0.98。_BA = 0.1 mol / L，F / W = 0.15，O / W＝ 0.3534，在第3阶段在pH 6.00下进料。研究表明，通过不对称分离，对于高ee的S-PN，萃取阶段所需的数量大大减少了。