Solubility of imidazoles, benzimidazoles, and phenylimidazoles in dichloromethane, 1-chlorobutane, toluene, and 2-nitrotoluene

Solubilities of seven imidazoles (1H-imidazole, 2-methyl-1H-imidazole, benzimidazole, 2-methylbenzimidazole, 2-phenylimidazole, 4,5-diphenylimidazole, and 2,4,5-triphenylimidazole) in organic solvents (dichloromethane, 1-chlorobutane, toluene, and 2-nitrotoluene) have been measured using a synthetic method and liquid chromatography. The interactions of the imidazoles, benzimidazoles, or phenylimidazoles with different solvents are discussed. The solubilities of these imidazoles in chloroalkanes were very low. In all solvents studied, the solubility of phenylmidazoles was significantly lower than the solubility of 1H-imidazole or benzimidazoles. Experimental results of solubility were correlated by means of the Wilson, UNIQUAC, and NRTL equations utilizing parameters derived from solid-liquid equilibria results. The existence of a solid-solid first-order phase transition in the solute has been taken into consideration in the solubility calculation. The best correlation of the solubility data was obtained by the Wilson equation with the average root-mean-square deviation sigma(T) equal to 3.2 K.