4-Amino-3,6-dichloropyridazine Solubility Measurement and Correlation in Seven Pure Organic Solvents from (278.15 to 333.15) K

Abstract

The solid−liquid equilibria of 4-amino-3,6-dichloropyridazine (ADCP) in seven pure organic solvents including methanol, acetone, ethanol, dichloromethane, ethyl acetate, 1,4-dioxane, and tetrahydrofuran were determined with the synthetic method from (278.15 to 333.15) K at atmospheric pressure using a laser monitoring observation technique. The measured solubility data increased with the rise of temperature. These solubility data were correlated with two models: the modified Apelblat and λh (Buchowski) equation. The relative deviation of the modified Apelblat equation was no more than 2.1 %, while that of λh equation was less than 4.5 %. Better correlation results were obtained in most solvents with modified Apelblat equation. Furthermore, using van't Hoff plot, the calculation was performed to obtain the apparent dissolution enthalpy and entropy of the solution of ADCP in these solvents, based on which the apparent dissolution Gibbs free energy change was deduced.

Solubility Measurement and Correlation of (+)-Biotin Intermediate Lactone in Different Organic Solvents from 287.15 to 323.75 K

“…The formula is given as follows: where x i is the mole fraction solubility of (+)-biotin intermediate lactone in different solvents, T is the absolute temperature in Kelvin, and a and b are model parameters (shown in Table ), which are obtained from regression of the experimental data. Here, for a real solution, it is rational to utilize this equation in consideration of the nonideality caused by the solvent effect …”

“…Here, for a real solution, it is rational to utilize this equation in consideration of the nonideality caused by the solvent effect. 12 Modified Apelblat Equation.…”

“…Here, for a real solution, it is rational to utilize this equation in consideration of the nonideality caused by the solvent effect. 12 Modified Apelblat Equation. The relationship of temperature and solubility was described by the modified Apelblat equation, 13,14 which is frequently used in correlation of solid− liquid equilibrium.…”