Solubility of 4-Chloro-2,5-dimethoxynitrobenzene, 4-Chloro-2,5-dimethoxyaniline, and 2,5-Dimethoxyaniline in Binary and Pure Solvents: Determination and Modeling

Using the dynamic method over the temperature range of (277 to 340) K at atmosphere pressure, solubility of 4-chloro-2,5-dimethoxynitrobenzene (CDMB) and 4-chloro-2,5-dimethoxyaniline (CDMA) in methanol-water and ethanol-water solvent mixtures, where solute-free mass fraction of methanol and ethanol range from 0.2 to 0.8, and solubility of CDMB, CDMA, and 2,5-dimethoxyaniline (DMAn) in 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, and diethylene glycol have been investigated. In all solvents, there exists a direct relationship between solubility and temperature. In mixture solvents, the experimental data are correlated using the Wilson and the NRTL models. The solubility of CDMB and CDMA increases with the added amount of methanol or ethanol. In pure organic solvents, significant differences are discerned for the solubility of CDMB, CDMA, and DMAn, and data are correlated with the Wilson, the NRTL, the modified Apelblat, and the lambda h models. The solubility of DMAn is strongly dependent on temperature, whereas CDMB is weakly dependent. On the basis of the solubility data and the solubility differences among CDMB, CDMA, and DMAn, ethanol-water solution is preferred to be the solvent for the reduction of CDMB, and diethylene glycol is suggested to be the recrystallization solvent used to separate DMAn from the system.