Coupling Chromatography and Crystallization for Efficient Separations of Isomers

Gedicke, K.; Beckmann, Wolfgang; Brandt, Andreas; Sapoundjiev, D.; Lorenz, Heike; Budde, U.; Seidel‐Morgenstern, A.

doi:10.1007/s10450-005-5990-8

Cited by 12 publications

(5 citation statements)

References 11 publications

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“…Multiobjective optimization of productivity and evaporation cost in terms of essential operating parameters (column length and SMB feed concentration) shows for this coupled process an optimum SMB purity value as a trade-off between increased SMB performance and recycle of the mother liquor. Further examples devoted to study quantitatively combinations of chromatography and crystallization were reported in [306][307][308] . All the results summarized here clearly indicate that the combined process can achieve better performance than the SMB process alone.…”

Section: Coupling Of Chromatography and Crystallizationmentioning

confidence: 99%

Processes To Separate Enantiomers

2014

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The provision of pure enantiomers is of increasing importance not only for the pharmaceutical industry but also for agrochemistry and biotechnology. In general, there are two rival approaches to provide pure enantiomers. The "chiral" approach is based on developing an asymmetric synthesis of just one of the enantiomers, while the "racemic" approach is based on separating mixtures of the two enantiomers. In the last few years remarkable progress has been achieved in the latter area. This Review focuses in particular on enantioselective crystallization processes and preparative chromatography, including hybrid processes and the incorporation of racemization steps. Several examples from our research are used for illustration purposes.

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Section: Coupling Of Chromatography and Crystallizationmentioning

confidence: 99%

Processes To Separate Enantiomers

2014

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“…The SMB technology was a breakthrough in increasing the productivity of chromatographic separations; however, a significative decrease in productivity can still be observed as the level of purification increases. For this reason, some authors have been pursuing the use of hybrid processes, combining SMB chromatography and crystallization in order to obtain an increase in productivity (Lim et al, 1995;Lorenz et al, 2001;Bléhaut et al, 2001;Gedicke, 2005;Lorenz et al, 2006). The general concept of the hybrid process is based on using chromatography as a prepurification stage, followed by a crystallization step to achieve the final purification.…”

Section: Enantioseparation Via Chromatography and Crystallizationmentioning

confidence: 99%

Ternary phase diagram of ketamine ((R,S)-2-(2-chlorophenyl)-2methylaminocyclohexanone) in ethanol and preliminary studies aiming at Enantioselective Crystallization of S-ketamine

Barros

Tamagawa

Santana

et al. 2009

Braz. J. Chem. Eng.

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-Crystallization is an important industrial-scale process for the purification of enantiomers that depends on a phase diagram. In this work, the ternary phase diagram of R-and S-ketamine in ethanol was determined. The eutectic point indicated that crystallization of pure enantiomers from solutions containing more than 75% of the desired enantiomer is feasible. Solubility studies showed the feasibility of using temperature control to conduct the process. Batch crystallization of ketamine (S/R:80/20) solutions at 25°C provided the isolation of S-ketamine (purity of 100%) with a yield from 65 to 70% and a productivity of 6.5 g/(l h).

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“…The present paper is part of a project to establish the feasibility and limitations of such a hybrid chromatography-crystallization process [12].…”

Section: Introductionmentioning

confidence: 99%

Partial Miscibility of Organic Compounds in the Solid State – The Case of Two Epimers of a Diastereoisomer

Beckmann¹,

Lorenz

2006

Chem Eng & Technol

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The purification that can be attained via crystallization is on the one hand governed by kinetic factors, such as the growth rate, and can on the other hand be limited by thermodynamic factors, such as the formation of a solid solution of the impurity with the product. For organic substances, these solid solubilities are difficult to establish, especially for low partial solubilities in the solid state. For the case of the crystallization of two epimers of a diastereoisomer, the formation of partial solid solutions with a respective solubility limited to approximately 5 % and 3 % has been shown using both DSC and XRPD measurements. The enthalpies of fusion of the solids are a strong function of the content of the opposite epimer. This can be interpreted with a disruption of bonds in the lattice, a disruption index of ∼ 8 is found. First determinations of the crystal structure of one of the epimers suggest the formation of a solid solution, which occurs via the replacement of dimers of molecules that are bound by two hydrogen bonds involving the epimeric hydroxyl group and a vicinal phenoxy group. By replacing dimers, the lattice distortion might be limited.

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Coupling Chromatography and Crystallization for Efficient Separations of Isomers

Cited by 12 publications

References 11 publications

Processes To Separate Enantiomers

Processes To Separate Enantiomers

Ternary phase diagram of ketamine ((R,S)-2-(2-chlorophenyl)-2methylaminocyclohexanone) in ethanol and preliminary studies aiming at Enantioselective Crystallization of S-ketamine

Partial Miscibility of Organic Compounds in the Solid State – The Case of Two Epimers of a Diastereoisomer

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