Solubility and Data Correlation of 2-Bromo-5-hydroxypyrazine in Four Cosolvent Mixtures and Ten Mono-Solvents from 278.15 to 323.15 K

The experimental solubility of 2-bromo-5-hydroxypyrazine dissolved in 10 mono-solvents (methanol, ethanol, isopropanol, N,N-dimethylformamide (DMF), n-propanol, acetonitrile, acetone, ethylene glycol (EG), propylene glycol (PG), water) and cosolvent mixtures of methanol + water, ethanol + water, isopropanol + water, and DMF + water was determined by the isothermal saturation method between 278.15 and 323.15 K at 101.2 kPa. The largest solubility was observed in DMF + 2-bromo-5-hydroxypyrazine for mono-solvent systems and in DMF + water for mixed solvent systems. The Jouyban–Acree model (J–A), van’t Hoff–Jouyban–Acree model (V–J–A), and Apelblat–Jouyban–Acree model (A–J–A) were utilized to correlate the 2-bromo-5-hydroxypyrazine solubility in mixtures, and the Apelblat model, van’t Hoff model, λh model, and Jouyban model were used to correlate the 2-bromo-5-hydroxypyrazine solubility in 10 mono-solvents. The preferential solvation of 2-bromo-5-hydroxypyrazine in mixed solvents was researched by calculation of δx1,3. This study presents insights into modulating the 2-bromo-5-hydroxypyrazine crystallization process and in understanding equilibrium behaviors in different solvents.