Synthesis, characterization, and evaluation of pyrimidinone-linked thiazoles: DFT analysis, molecular docking, corrosion inhibition, and bioactivity studies

Abstract

The paper describes the construction of a new series of pyrimidinone-linked thiazole derivatives through bromination of the initial Biginelli reaction product followed by the Hantzsch thiazole synthesis route. Various analytical techniques, including FT-IR, 1H NMR, 13C NMR, and LCMS analysis, were employed to confirm the formation of the products. The synthesized compounds were primarily evaluated for their antibacterial activity, with a specific focus on their IC50 values. Compound 4c demonstrated the most potent efficacy, displaying MIC and MBC values that varied from 0.23 to 0.71 mg/mL and 0.46–0.95 mg/mL, respectively. The anti-inflammatory potential was also observed in analogs 4a and 4c with marked activity in the 33.2–82.9 μM concentration range. Moreover, compounds 4a, and 4c demonstrated strong antioxidant effects, as reflected by their excellent IC50 values of 38.6–43.5 μM respectively. DFT investigation showed that B. cereus was more susceptible, and E. coli was more resistant, with chloro-substituted compounds exhibiting potential reactivity. Some molecules with chloro-substituents showed promising results in density functional theory when compared to other substituents. In addition, the molecules underwent a corrosion study and demonstrated a high level of inhibition efficiency (4c) in comparison to other molecules. Further in silico studies of the synthesized thiazoles confirmed the good interactions with the target.

Keywords

• Pyrimidinone
• Biginelli reaction
• Thiazole
• Antibacterial
• Corrosion inhibition
• Hantzsch synthesis