Solubility Measurement and Modeling of Methyl 2-Aminopyridine-4-carboxylate in Four Binary Blends and Eight Monosolvents from 278.15 to 323.15 K

Experimental mole fraction solubility of methyl 2-aminopyridine-4-carboxylate in methanol/ethanol/isopropanol/n-propanol/acetonitrile/toluene/water/N,N-dimethylformamide (DMF) and ethanol/n-propanol/acetonitrile/DMF + water was determined by the isothermal saturation method between 278.15 and 323.15 K at 101.2 kPa. For methyl 2-aminopyridine-4-carboxylate + monosolvents, the increase of temperature was synchronized with the increase of solubility, and the maximum solubility (0.0377 and 323.15 K) was obtained in methyl 2-aminopyridine-4-carboxylate + toluene. For methyl 2-aminopyridine-4-carboxylate + mixed solvents, in addition to temperature, the proportion of cosolvents was also the main influencing factor, and the maximum solubility of methyl 2-aminopyridine-4-carboxylate (0.02845 and 323.15 K) was obtained in DMF + water at wDMF = 0.9. The Jouyban–Acree model (J-A), van't Hoff–Jouyban–Acree model (V-J-A), and modified Apelblat–Jouyban–Acree model (A-J-A) were utilized to correlate the solubility of methyl 2-aminopyridine-4-carboxylate in four binary solvent mixtures, and Apelblat model, van't Hoff model, and λh model were used to correlate the methyl 2-aminopyridine-4-carboxylate solubility in eight monosolvents. This study presented insights into modulating a methyl 2-aminopyridine-4-carboxylate crystallization process and understanding equilibrium behaviors in different solvents.