Journal of Chemical and Engineering Data, Vol.64, No.12, 5578-5583, 2019
Solubility Determination of 2-Chloronicotinic Acid and Analysis of Solvent Effect
The objective of this work is to study the effect of solvent properties on solubility. In this work, the solubility of 2-chloronicotinic acid in methanol, ethanol, n-propanol, isopropanol, N,N-dimethylformamide (DMF), 1,4-dioxane, N-methyl pyrrolidone (NMP), ethyl acetate, acetone, water, acetonitrile, and cyclohexane at temperatures ranging from 273.15 to 313.15 K was determined by the isothermal saturation method under P = 101.3 kPa. The maximum solubility value was obtained in pure NMP, followed by in DMF > ethyl acetate > acetone > 1,4-dioxane > n-propanol > isopropanol > ethanol > methanol > acetonitrile > cyclohexane > water. The obtained solubility data of 2-chloronicotinic acid in twelve pure solvents were correlated with the modified Apelblat equation and lambda h equation. The maximum values of relative average deviations and root-mean-square deviation are no larger than 2.72 X 10(-2) and 35.56 x 10(-4), respectively, which indicates that the experimental data are well-consistent with the calculated ones. Furthermore, the properties of the solvent including hydrogen bond acidity (alpha), hydrogen bond basicity (beta), dipolarity/polarizability (pi*), and the Hildebrand solubility parameter (delta(2)(H)) were discussed. Compared with the polarity of the solvent, the hydrogen bond formed between the solvent and solute molecule is the main influencing factor. Understanding some physical properties of 2-chloronicotinic acid in commonly used organic solvents is important in drug crystallization.