| Autor: |
Di Silvestro, Giuseppe, Palmisano, Giovanni, Pellegata, Renato |
| Zdroj: |
Journal of Pharmaceutical Sciences; July 1993, Vol. 82 Issue: 7 p758-760, 3p |
| Abstrakt: |
The phase diagram of (R)- and (S)-4-hydroxy-2-pyrro(idone presents a conglomerate in the racemic mixture. The enthalpy of melting extrapolated by the Schröder-van Laar-Le Chatelier equation [change in enthalpy (ΔH) = 28410 J/mol; melting temperature (TA) = 429.9 K; solidus temperature (Ts) = 395.4 K] and the value determined by differential scanning calorimetry (ΔH= 28494 J/mol; TA= 429.6 K; Ts= 394.6 K) are in excellent agreement. The experimental entropy of the mixing of enantiomers is 5.69 J/mol ⋅ K. The conglomerate nature of the racemic mixture was confirmed by X-ray and IR spectroscopy. The presence of solvates was also observed. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Plný text