Mechanism of the solvent-mediated transformation of taltirelin polymorphs promoted by methanol
| Autor: | Hiroshi Ooshima, Shoji Maruyama |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Stereochemistry
General Chemical Engineering Nucleation General Chemistry Nuclear Overhauser effect Crystal structure Medicinal chemistry Industrial and Manufacturing Engineering law.invention Solvent Taltirelin chemistry.chemical_compound chemistry law Environmental Chemistry Methanol Crystallization Dissolution |
| Zdroj: | Chemical Engineering Journal. 81:1-7 |
| ISSN: | 1385-8947 |
| Popis: | Taltirelin, a central nervous system activating agent, has two crystal forms (α- and β-forms). Previously it has been reported that methanol (MeOH) as a co-solvent promoted the solvent-mediated phase transformation from α-form to β-form. In the present study, the mechanism of the promotion was investigated. Of the three processes in the solvent-mediated transformation, namely dissolution of the metastable form, nucleation of the stable form, crystal growth of the stable form, MeOH promoted the latter two processes. In particular, the nucleation was strongly promoted. The nOe (nuclear Overhauser effect) data suggested that MeOH promotes the conformational change from the α-form to the β-form. The solute–MeOH interaction resulted in the formation of pseudo-polymorphs of the β-form (2H2O·MeOH or H2O·2MeOH solvate), although these pseudo-polymorphs were exchangeable to the β-form (4H2O solvate) under a humid atmosphere. Based on these findings, a possible mechanism of the transformation of taltirelin polymorphs in the presence of MeOH was discussed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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