Theoretical Study of Some Imidazo[1,2-a]Pyrimidines: Structural Optimization, Mechanism and Spectroscopy

Subject Areas :

maryam  khashi ¹ (Department of Chemistry, Faculty of Science, Mashhad Branch, Islamic Azad University, Mashhad, Iran.)
ali  beyramabadi ² (Department of Chemistry, Faculty of science, Islamic azad University, mashhad branch, mashhad, iran)
abolghasem  davoodnia ³ (Department of chemistry, faculty of science, islamic azad university, mashhad branch, mashhad, iran)
niloofar  vafaeenejad ⁴ (Department of Chemistry, Faculty of science, Islamic Azad University, Mashhhad Branch, Mashhad, Iran.)

Received: 2021-07-02 Accepted : 2021-08-19 Published : 2021-02-19

Keywords: Dimroth, density functional theory, 2-a]pyrimidine, Imidazo[1, rearrangement, Nucleophilic Acyl substitution,

Abstract :

In this research, density functional theory calculations were used to optimize the structure of imidazo[1,2-a]pyrimidine derivatives and for comparing the theoretical and experimental data of NMR and FTIR spectra. All structures were optimized using the B3LYP/6-31+G(d,p) computational level. Comparison of energy levels showed that the hydrogen bonds can play an important role in the stability of isomers. Also, the activation energy of the three reactions was calculated by evaluation of the transition state energy. The study of the activation energy showed that isomers with ester functional group were participated faster than isomers with carboxylic acid functional group in the reactions of nucleophilic acyl substitution. Also, comparison of theoretical and experimental data of NMR and FTIR spectra showed good agreement with experimental data.