Enantiomeric 3-chloromandelic acid system: Binary melting point phase diagram, ternary solubility phase diagrams and polymorphism

✍ Scribed by Tam Le Minh; Jan von Langermann; Heike Lorenz; Andreas Seidel-Morgenstern

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 762 KB
• Volume: 99
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.22234

✦ Synopsis

A systematic study of binary melting point and ternary solubility phase diagrams of the enantiomeric 3-chloromandelic acid (3-ClMA) system was performed under consideration of polymorphism. The melting point phase diagram was measured by means of thermal analysis, that is, using heat-flux differential scanning calorimetry (DSC). The results reveal that 3-ClMA belongs to the racemic compound-forming systems. Polymorphism was found for both the enantiomer and the racemate as confirmed by X-ray powder diffraction analysis. The ternary solubility phase diagram of 3-ClMA in water was determined between 5 and 50 degrees C by the classical isothermal technique. The solubilities of the pure enantiomers are extremely temperature-dependent. The solid-liquid equilibria of racemic 3-ClMA are not trivial due to the existence of polymorphism. The eutectic composition in the chiral system changes as a function of temperature. Further, solubility data in the alternative solvent toluene are also presented.