Mechanics Of Separation Of Mandelic Acid With Calsium And Process Optimization

Objective: To study mechanism of chiral separation of mandelic acid withd-pseudoephadrine in calcium ion participated. Optimize the technique with which d-PEseparated mandelic acid involved in calcium ion. Explore the impact of the coexistenceions with calcium on the separating efficiency. Preliminary study the feasibility ofd-pseudoephedrine separate mandelic acid analogues and d-mandelic acid separatepseudoephadrine analogues involved in calcium ions. Methods: using optically pure ofmore than98%of d-pseudoephedrine and optically pure of more than98%of d-mandelicacid salified in absolute alcohol, add calcium precipitant and gain pure d.d-Ca salt for thestudy of mechanismuse.Use optically pure d-PE and d-MA salified in absolute alcohol addcalcium, magnesium and kalium ions precipitant and gain d.d-Ca salt, investigate theeffect of Mg2+and K+to the Role of calcium ion involved in the separation.Orthogonaldesign investigated time,temperature to the synthesis of diastereoisomer.use d-PE separateo-chloromandelic acid and use d-MA separate clorprenaline, Examine the feasibility ofsaparate analogs, and certify the mechanism. Results: Powder X-ray diffraction confirmedthat in the participation of calcium ions d-pseudoephedrine produce the formation ofhigh-purity crystalline compound with d-mandelic acid, Single crystal cultured clusterscrystalline. Mg2+, K+ions have a synergistic effect on Ca2+, After the optimization of theseparation (Compared with the previous), separation efficiency of d-MA was38.64%（previous was34.65%）optical purity before recrystallisation was93.86%（previous was87.36%）separation efficiency of l-MA was38.43%(previous was32.99%)optical puritybefore recrystallisation was85.46%(previous was67.04%). Separation of Analoguesinvolved in calcium ions has not been successed. Conclusion: d.d-Ca salt was a sandwichring structure of highly three-dimensional region-specific and electrical requirements. saturated salt water With Calcium coordinated by Mg2+and K+can improve separationefficiency and the optical purity of mandelic acid which separated by d-pseudoephedrineinvolved in calcium ions. on account of calcium of d.d-Ca salt have a highly specificity ofthree-dimensional regional and intermolecular forces, the separation of mandelic acidanalogues and pseudoephedrine analogues involved in the calcium ions did not achieve asatisfactory result.