Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Knowledge of solubility for ethyl 5-amino-4-cyano-3-(2-ethoxy-2-oxoethyl)-2-thiophenecarboxylate (ACET) in different solvents is essential for its purification and further theoretical studies. In this paper, the solubility of ACET in selected pure solvents, including methanol, ethanol, 1-butanol, n-propanol, isopropanol, toluene, ethyl acetate, acetonitrile and acetone were acquired by a high-performance liquid chromatography (HPLC) at T = (273.15, 278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K under pressure of 0.1 MPa. Generally, they obeyed the following order from high to low in different solvents: acetone greater than ethyl acetate greater than acetonitrile greater than methanol greater than ethanol greater than isopropanol greater than n-propanol greater than 1-butanol greater than toluene. The obtained solubility data of ACET in selected solvents were correlated by the van t Hoff equation, modified Apelblat equation, kh equation, Wilson model and NRTL model. The correlated values of the five equations agreed well with the experimental values and the Wilson model gives better correlation results than other models. Furthermore, the standard dissolution enthalpy and excess enthalpy for dissolution process of ACET were calculated from the experimental solubility by using the van t Hoff equation. The solubility values of ACET in different solvents and thermodynamic relations would be invoked as fundamental data and models regarding the crystallization process of ACET.