Optimization of the cooling profile to improve the filterability of crystals isolated during an optical resolution by diastereomeric salt formation
✍ Scribed by L. Lerond; H. Muhr; E. Plasari; M. Hassoun; E. Valery; O. Ludemann-Hombourger
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 927 KB
- Volume
- 190
- Category
- Article
- ISSN
- 0032-5910
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✦ Synopsis
The crystallization of a diastereomeric salt during the optical resolution of a synthesized intermediate led to crystals showing poor filterability. With a view to decrease the duration of the filtration step, linear cooling profiles, including a preliminary stabilization step, and non-linear cooling profiles (quoted as controlled type) are tested. This latter type of profile enables a significant increase of mother liquors flowrate during filtration (from 50% to 300% according to crystallization duration). Scanning Electron Microscopy observations of crystals confirmed the trends deducted from the comparison of mean mother liquors flowrates: the promotion of crystal growth over nucleation leads to wider (and fewer small) crystals exhibiting an improved filterability.