Experimental Assessment and Modeling of the Solubility of Malonic Acid in Different Solvents

Malonic acid is widely applied in the pharmaceutical industry as a drug intermediate and for acidity control in drug production. Its solubility in five pure solvents and one binary solvent mixture was measured. The results reveal that, in the solvents studied, the solubility increases with increasing temperature. Different thermodynamic models were applied to correlate the solubility data in the pure and binary solvents and were found to match well with the experimental data. Computational investigations performed using molecular dynamics simulations showed that, in the pure alcohol solvents, both the solute-solvent interaction and the solvent-solvent interaction affect the solubility behavior, while in the case of the pure solvents acetone and acetonitrile, the solute-solvent interaction is the key factor.