رسائل ماجيستير
English
2022
Synthesis, Characterization, Coordination Compounds, Molecular Orbital Study, and Biological Activity of 1,2,4-triazolo[1,5-c]pyrimidine-5(6H)-ones
سالي علي أحمد الأسمر, محمد أبو الحاج
جامعة القدس · فلسطين
The condensation of a 1,2,4-triazole ring with a pyrimidine ring produces 1,2,4-triazolopyrimidines, which are bicyclic heterocycles. Because the relative orientation of each ring can take four different forms, four separate isomeric families of compounds can be established. The 1,2,4-triazolo[1,5-a]pyrimidine derivatives are the most investigated because they are thermodynamically more stable, and the same goes for 1,2,4-triazolo[1,5-c]pyrimidine, but there is not enough research on it. There have also been revisions on the synthesis, reactivity, spectroscopic characterization, and crystallographic studies of 1,2,4-triazolo[1,5-c]pyrimidines, 1,2,4-triazolo[4,3-a]pyrimidines, and 1,2,4-triazolo[4,3-c]pyrimidines. However, it's worth noting that combining the two rings into a single molecule may boost biological activity.
Our thesis focuses on researching and investigating triazolopyrimidine coordination chemistry. We synthesized and characterized 1,2,4-triazolo[1,5-c]pyrimidine-5(6H)-ones. In this thesis, we adopted the optimal approach through synthesis and modification to reach the highest yield. The substance was identified using standard procedures, with positive results. The Spartan program was also used to investigate the computational chemistry of this molecule; two models were utilized: semi-empirical and Hartree-Fock. Using heat of formation, the most stable tautomer has been discovered. Aside from that, Molecular Orbital Calculation and Electrostatic Atomic Charge were determined. The results showed that the possibility of binding the ligand with metal will be as follows: N3 > N4 > O1. This theoretical study was corroborated by X-ray analysis of the complex and showed that bonding occurred through the nitrogen atom in position 3 of the pyrimidine ring and the nitrogen atom in position 4 of the triazole ring as well.
The coordination chemistry of 1,2,4-triazolo[1,5-c]pyrimidines has never been studied before. Metal complexes of the first and second row transition metals: Silver(I), Copper(II), Nickel(II), Cobalt(II), Fe(II), Platinum(II), Palladium(II), and Ruthenium(III) were synthesized and used to manufacture and study the capacity to build coordination compounds from the ligand. Some of these coordination compounds were isolated in single crystal form, while others require more examination; X-ray crystallography was used to characterize the coordination compounds.
The biological activity of 1,2,4-triazolo[1,5-c]pyrimidine and its coordination compounds as antibacterial and antimalarial agents was investigated; it was found to have good antibacterial activity and minor effects as antimalarials, except for the platinum(II) coordination compound, which showed high efficacy as an antimalarial compared to the chloroquine drug. Its antimalarial effect has been maintained even at low concentrations. This could be a good sign to introduce it as an alternative treatment. Other biological functions of these chemicals are possible. However, it is recommended to investigate these coordination compounds for anticancer activity, especially the platinum(II) coordination compound.
