Infrared spectroscopy studies of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine (MDOP) in 12 pure organic solvents were undertaken to investigate the solvent-solute interactions. The frequencies of the carbonyl (C=O) of MDOP were correlated with solvent properties such as solvent acceptor number (AN) and the linear solvation energy relationships (LSER). These frequencies showed a good correlation with the solvent acceptor number (AN) and the LSER.