Measurement and Correlation of the Solubility, Dissolution Enthalpy, and Entropy of R-2[4-(6-Chloro-2-benzoxazolyloxy)phenoxy]propanoic Acid in Different Pure Solvents

The solubility of R-2[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propanoic acid (abbreviated as Fenoxaprop-P) in acetone, methyl ethyl ketone (MEK), 1,4-butyrolactone, acetonitrile, DMF, isopropyl alcohol (IPA), n-butyl alcohol and THF were measured at temperatures ranging from 273.15 to 323.15 K at atmospheric pressure using a laser detecting system. First, the solubility data were correlated by the Buchowski–Ksiazczak λh equation and modified Apelblat equation. Compared with the Apelblat equation, the Buchowski–Ksiazczak λh equation can fit the solubility data well. Then, the dissolution enthalpy, entropy and Gibbs free energy of Fenoxaprop-P were predicted by the van’t Hoff and Gibbs equation.