Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Physicochemical Properties and the Crystallization Thermodynamics of the Pure Enantiomer and the Racemate for N-Methylephedrine

Wang, X. J.[Xiu Juan], Wiehler, H.[Harald], Ching, C. B.[Chi Bun]
J. Chem. Eng. Data 2003, 48, 5, 1092-1098
ABSTRACT
The binary melting point phase diagram of (+)- and (-)-N-methylephedrine was determined. It was shown that (1)-N-methylephedrine is a racemic conglomerate. The enthalpies of fusion of (+)-N-methylephedrine and of (1)-N-methylephedrine and the entropy of mixing of (+)- and (-)-N-methylephedrine were calculated using the thermal data. The nature of the (1)-N-methylephedrine crystalline racemate was also confirmed by means of comparison of solid-state infrared spectra and powder X-ray diffraction patterns of the racemic mixture with those of one of the enantiomers. The solubility and supersolubility diagrams of (1)-N-methylephedrine in a mixed solvent of 2-propanol and water were determined over the temperature range (7 to 30) C. The ternary phase diagram of (+)- and (-)-N-methylephedrine with the mixed solvent was constructed at (15, 20, 25, and 30) C.
Compounds
# Formula Name
1 C11H17NO (+)-N-methylephedrine
2 C11H17NO (-)-N-methylephedrine
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DSC
  • 1
  • POMD
  • 1
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 2
  • 1
  • Eutectic temperature, K ; Crystal - 2
  • Crystal - 2
  • Crystal - 1
  • Liquid
  • Air at 1 atmosphere
  • DIROBS
  • 1
  • POMD
  • 2
  • 1
  • Solid-liquid equilibrium temperature, K ; Liquid
  • Mole fraction - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • DTA:UFactor:4
  • 12