The present work describes the synthesis, characterization, and solubility studies of some biologically active pyrimidine derivatives. The characterization of these synthesized compounds was done by mass, IR, and H-1 NMR spectral techniques. Further, the solubility of these compounds has been studied in methanol, N,N-dimethylformamide (DMF), and carbon tetrachloride (CCl4) by gravimetrical method from (298.15 to 328.15) K under atmospheric pressure, and the solubility data were correlated against temperature. The solubility is found to increase with temperature and order of solubility is found to be DMF > methanol > CCl4. The modified Apelblat and BuchowskiKsiazczak lambda h equations were used to correlate the experimental solubility data. Further, some thermodynamic parameters such as dissolution enthalpy (Delta H-sol), Gibbs free energy (Delta G(sol)), and entropy (Delta S-sol) of mixing have also been calculated. The positive values of enthalpy and Gibbs energy of solution suggest that the dissolution process to be endothermic and is spontaneous.