Study on the Solubilities of Mononitro-Substituted Products of Nitration of m-Toluic Acid in Several Solvents at Temperatures between 297.65 and 351.75 K

Mononitro-substituted products derived from the nitration of m-toluic acid are 3-methyl-4-nitrobenzoic acid, 3-methyl-2-nitrobenzoic acid, and 5-methyl-2-nitrobenzoic acid, which are all crucial intermediates of pesticides and medicines. The solubilities of 3-methyl-4-nitrobenzoic acid, 3-methyl-2-nitrobenzoic acid, and 5-methyl-2-nitrobenzoic acid in water, methanol, ethanol, n-propanol, formic acid, acetic acid, and propanoic acid were measured at different temperatures (297.65–351.75 K) and under atmospheric pressure. As expected, the same solute has different solubilities in different solvents, and the dissolved amounts of these three solutes are also diverse in the same solvent. Subsequently the experimental solubility data of three mononitro-substituted products of m-toluic acid nitration in several solvents were correlated with the modified Apelblat equation and the NRTL activity coefficient model, and the calculated values are in excellent agreement with known experimental data in the temperature range studied.