Pyrimidine derivatives have biological and pharmacological properties. Therefore, in this study we focused on the synthesis various Pyrimidine derivatives to make noteworthy contributions this class of heterocyclic compounds. In the present study, the new compounds (4-6) were obtained by the reactions of 1-amino-5-benzoyl-4-phenylpyrimidin-2(1H)-one (1), 1-amino-5-(4-methylbenzoyl)-4-(4-methylphenyl)pyrimidin-2(1H)-one (2) and 1-amino-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (3) with dimethyl acetylenedicarboxylate. The structures of these compounds were proved by elemental analysis, FT-IR, H-1 and C-13-NMR spectra. In addition to, quantum chemical calculations were made to find molecular properties of the pyrimidin-1(2H)-ylaminofumarate derivatives (4-6) by using DFT/B3LYP method with 6-311++G(2d,2p) basis set. Quantum chemical features such as E-Homo, E-LUMO, energy gap, ionization potential, chemical hardness, chemical softness, electronegativity etc. values for gas and solvent phase of neutral molecules were calculated and discussed.