Experimental Determination and Thermodynamic Models for Solid-Liquid Equilibrium of 4-(4-Aminophenoxy)- N-methylpyridine-2-carboxamide in Pure and Binary Solvent Mixtures for T = (278.15-328.15) K

In this study, the solubility of 4-(4-aminophenoxy)-N-methylpyridine-2-carboxamide (APMC) in pure tetrahydrofuran, ethyl acetate, acetonitrile, n-butanol, n-propanol, ethanol, methanol, and three binary solvent mixtures (ethyl acetate + methanol, ethyl acetate + ethanol, and ethyl acetate + n-butanol) was first experimentally determined within the temperature range from (278.15 to 328.15) K under atmosphere pressure by the gravimetric method. The results reveal that the solubility of APMC increases with an increase in temperature in all of the solvents selected. The modified Apelblat equation and the Buchowski-Ksiazaczak λh equation were used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R-K model, and the Jouyban-Acree model were applied to correlate the solubility in binary solvent mixtures. All of the models could be well applied, and the modified Apelblat equation stood out to be more suitable with a higher accuracy compared to that of the other three models.