Functionalization Strategies for Electropolishing Process of Carbon Steel Using Novel Quinazoline-4-one Derivatives: Synthesis, Spectroscopic Characterization, and DFT Studies

A novel class of organic electropolishing (EP) inhibitors, entitled quinazoline-4-one derivatives (benzylidene oxoquinazolineyl acetohydrazide (BOA)), has laid a solid foundation for the creation of a new efficient inhibitor platform for the dissolution of carbon steel (C-steel) in 8 M H3PO4. Fourier-transform infrared (FTIR), 1H NMR, and elemental analyses have all been employed to identify BOA's functional groups, components, and active centers. The inhibition strength of BOA derivatives (m-NBOA, p-HBOA, and p-BBOA) on C-steel was assured by galvanostatic polarization measurements. Within the range of concentrations (0.33-3.43 × 10-3 mol/L) and temperatures (298-313 K) evaluated, the tested derivatives exhibit extraordinarily high gloss and low roughness, and improved the corrosion resistance of the electropolished surface with the lowest negative environmental impact. The dissolution rate (IL) decreases with increasing BOA concentration, supporting a mass transport-controlled technique and demonstrating that BOA is appropriate for anodic inhibitors. Activation energy indicates physical adsorption. Thermodynamic parameters were calculated for further investigation of the heat involved and the mechanism of the EP process. Adsorption isotherm and adsorption thermodynamics parameters were discussed using three models: Langmuir, Flory-Huggins, and kinetic adsorption isotherms, to study the inhibition of EP of the steel surface. The free energy of adsorption was calculated to assert the physisorption process. A scanning electron microscope (SEM) was utilized to inspect the morphology of the metal surface before and after the inclusion of BOA under different conditions. In contrast, the surface roughness was identified using an atomic force microscope (AFM) and reflectance. Eventually, practical results have been proved through computational calculations using the LYP correlation functional by the density functional theory (DFT) method.

Regioselective Synthesis and Molecular Docking Studies of 1,5-Disubstituted 1,2,3-Triazole Derivatives of Pyrimidine Nucleobases

1,2,3-triazoles are versatile building blocks with growing interest in medicinal chemistry. For this reason, organic chemistry focuses on the development of new synthetic pathways to obtain 1,2,3-triazole derivatives, especially with pyridine moieties. In this work, a novel series of 1,5-disubstituted-1,2,3-triazoles functionalized with pyrimidine nucleobases were prepared via 1,3-dipolar cycloaddition reaction in a regioselective manner for the first time. The N1-propargyl nucleobases, used as an alkyne intermediate, were obtained in high yields (87-92%) with a new two-step procedure that selectively led to the monoalkylated compounds. Then, FeCl₃ was employed as an efficient Lewis acid catalyst for 1,3-dipolar cycloaddition between different aryl and benzyl azides and the N1-propargyl nucleobases previously synthesized. This new protocol allows the synthesis of a series of new 1,2,3-triazole derivatives with good to excellent yields (82-92%). The ADME (Absorption, Distribution, Metabolism, and Excretion) analysis showed good pharmacokinetic properties and no violations of Lipinsky's rules, suggesting an appropriate drug likeness for these new compounds. Molecular docking simulations, conducted on different targets, revealed that two of these new hybrids could be potential ligands for viral and bacterial protein receptors such as human norovirus capsid protein, SARS-CoV-2 NSP13 helicase, and metallo-β-lactamase.

Design, Synthesis, and the Biological Evaluation of a New Series of Acyclic 1,2,3-Triazole Nucleosides

A new strategy for the synthesis of N3 -benzoylated- and N3 -benzylated N1 -propargylquinazoline-2,4-diones 30a-d and 31a-d from isatoic anhydride 41 is reported. The alkynes 30a-d and 31a-d were applied in the 1,3-dipolar cycloadditions with azides 27 and 28 to synthesize acyclic 1,2,3-triazole nucleosides. The obtained alkynes and 1,2,3-triazole were evaluated for antiviral activity against a broad range of DNA and RNA viruses. The alkyne 30d showed activity against adenovirus-2 (EC50  = 8.3 μM), while compounds 37a and 37d were also active toward herpes simplex virus-1 wild-type and thymidine kinase deficient (HSV-1 TK- ) strains (EC50 values in the range of 4.6-13.8 μM). In addition, compounds 30a, 30b, 37b, and 37c exhibited activity toward varicella-zoster virus (VZV) TK+ and TK- strains (EC50  = 2.1-9.5 μM). The compound 30b proved to be the most selective against VZV and displayed marginal activity against human cytomegalovirus (HCMV). Although the compound 30a had improved anti-HCMV activity, the increase in anti-HCMV activity was accompanied by significant toxicity. Compounds 37a and 37d showed inhibitory effects toward the human T lymphocyte (CEM) cell line (IC50  = 21 ± 7 and 22 ± 1 μM, respectively), while compound 35 exhibited cytostatic activity toward HMEC-1 cells (IC50  = 28 ± 2 μM).

CuSO4/KI As Catalyst for the Synthesis of 1,4-Disubstituted-1,2,3-Triazolo-Nucleosides

A simple and inexpensive procedure has been developed for the selective formation of 1,4-disubstituted-1,2,3-triazolo-nucleosides starting from organic azides and terminal alkynes, mediated by in situ generated copper(I) catalyst from readily available CuSO4 and KI.

Synthesis of new 1,2,3-triazol-4-yl-quinazoline nucleoside and acyclonucleoside analogues

In this study, we describe the synthesis of 1,4-disustituted-1,2,3-triazolo-quinazoline ribonucleosides or acyclonucleosides by means of 1,3-dipolar cycloaddition between various O or N-alkylated propargyl-quinazoline and 1'-azido-2',3',5'-tri-O-benzoylribose or activated alkylating agents under microwave conditions. None of the compounds selected showed significant anti-HCV activity in vitro.