A Green Protocol for Simple One-Pot Synthesis of New Pyrimidine Derivatives Both Microwave Irradiation and Conventional Heating: Reactions, Characterization, and Theoretical Calculations

Abstract

In this research, 5-benzoyl-6-phenyl-4-(4-trifluoromethylphenyl)-2-{oxo and thioxo}-3,4-dihydro-1H-pyrimidines (1, 2) were synthesized by using multicomponent cyclocondensation reaction under microwave irradiation and classical heating. Compounds 3, 4, 6, 7, and 8 obtained reactions of 5-benzoyl-6-phenyl-4-(4-trifluoromethylphenyl)-2-thioxo-3,4-dihydro-1H-pyrimidine (1) and acetic anhydride, diethyl 2-bromomalonate, bromoacetic acid, 3-bromopropionic acid, methyl iodide, respectively. Compound 4 was both acetylated and hydrolyzed in acetic acid to give compound 5. The structures of all compounds were determined by using spectroscopic techniques like FT-IR, H-1/C-13 NMR, and elemental analyses, and the structures of compounds 1 and 3 were analyzed by X-ray crystal analysis. In addition, the quantum chemical parameters and full geometry optimizations for all compounds were computed using density functional theory based on B3LYP and the 6-31G (d, p) basis set.