Magdy Ahmed Ibrahim

Synthesis, C-3 functionalization, and chemical transformations of 6-alkyl-4-hydroxy-3-substituted-pyrano[3,2- c ]quinoline-2,5(6 H )-diones, with their biological, optical, electronic, photovoltaic, and corrosion applications.

The reaction of 3-(6,8-dimethylchromonyl)acrylonitrile ( 1 ) with cyanoacetamide ( 2 ) under basic conditions afforded a novel heterocyclic system: 5-cyanomethylchromeno[4,3- b ]pyridine-3-carbonitrile ( CCPC , 3 ). The transformation proceeds via a cascade mechanism involving initial Michael addition, retro - Michael -induced γ-pyrone ring opening and subsequent double recyclization steps. The structure of compound 3 was confirmed by analytical and spectral data. Its optimized molecular geometry and electronic properties were investigated using density functional theory (DFT/B3LYP) with the 6-311 + + G(d,p) basis set. Key global reactivity descriptors including electronegativity (χ), chemical potential (µ), electrophilicity index (ω), softness (S), and hardness (η) were calculated. Molecular electrostatic potential (MEP) maps provided insight into reactive sites. The experimental IR and NMR spectra exhibited strong agreement with theoretical predictions, validating the computational model. Swiss ADME analysis confirmed that all evaluated physicochemical parameters conform to Lipinski’s and Veber’s rules, indicating favorable drug-likeness. Additionally, non-linear optical (NLO) properties and quantum chemical descriptors were examined. Natural bond orbital (NBO) analysis revealed intramolecular charge transfer characteristics. Thermo kinetic behavior of CCPC was evaluated using the KiSThelP package across the temperature range 250–400 K in the gas phase and in various solvents (water, ethanol, acetone, dioxane, and DMSO). Rate constants (k _uni ) were estimated via transition state theory (TST) and unimolecular Eckart tunneling corrections. UV–Vis spectra were simulated using TDDFT-CAM-B3LYP/6-311 + + G(d,p), revealing solvent-dependent shifts in absorption maxima (λ _max ) and transition intensities. The nature of the electronic excitations was analyzed based on molecular orbital contributions.

Ring opening and recyclization reactions with 4-hydroxy-6-methyl-3-nitro-2 H -pyrano[3,2- c ]quinoline-2,5(6 H )-dione (1) was examined towards some carbon nucleophilic reagents.

A new Schiff base ligand, HNMPC, was prepared and reacted with some metal ions, including Cu(II), Ni(II), Co(II), Mn(II), and VO(IV). The infrared, electronic, mass, electron spin resonance, nuclear magnetic resonance, thermal and elemental analysis, molar conductance, and magnetic susceptibility measurements were used to characterize the metal complexes. The HNMPC ligand acts as a monoanionic tridentate ONO donor in all complexes, and the coordinating sites are C=O_pyridone, C=N, and the phenolate anion. All metal complexes exhibit octahedral configurations, and the results showed that the metal ion:ligand ratio was 1:2. The molecular structural parameters of the ligand and its metal complexes were determined based on the DFT level implemented in the Gaussian 09 program B3LYP/GENECP method at the 6‐311G(d,p) basis set for C, H, N, and O atoms and the SDD (Stuttgart/Dresden) basis set for the metal atoms. The theoretical data were correlated with the experimental results. Gram‐positive bacteria, Gram‐negative bacteria, yeast, and fungi were used to test the current compounds' antimicrobial activity. Investigating the antitumor activity of the ligand and its complexes against the HepG2 cell lines showed encouraging IC₅₀ values that were on par with those of cisplatin. In order to determine the affinity and binding pattern for the synthesized compounds toward the VEGFR‐2 active site, molecular docking studies were conducted, and the results were correlated with antitumor data. Based on the obtained results, future work aimed to synthesize a new category of Schiff bases and their metal complexes derived from the current aminopyridine derivative with diverse aldehydes and ketones.

2-Chloropyridine-3-carbonitrile derivative 1 was utilized as a key precursor to build a series of linear and angular annulated pyridines linked to a 6-hydroxy-4,7-dimethoxybenzofuran moiety. Reaction of substrate 1 with various hydrazines afforded pyrazolo[3,4-b]pyridines. Treatment of substrate 1 with 1,3-N,N-binucleophiles including 3-amino-1,2,4-triazole, 5-amino-1H-tetrazole, 3-amino-6-methyl-1,2,4-triazin-5(4H)-one and 2-aminobenzimidazole produced the novel angular pyrido[3,2-e][1,2,4]triazolo[4,3-a]pyrimidine, pyrido[3,2-e][1,2,4]tetrazolo[1,5-a]pyrimidine, pyrido[3′,2′:5,6] pyrimido[2,1-c][1,2,4]triazine and benzo[4,5]imidazo[1,2-a]pyrido[3,2-e]pyrimidine, respectively. Reaction of substrate 1 with 1,3-C,N-binucleophiles including cyanoacetamides and 1H-benzimidazol-2-ylacetonitrile furnished 1,8-naphthyridines and benzoimidazonaphthyridine. Moreover, reacting substrate 1 with 5-aminopyrazoles gave pyrazolo[3,4-b][1,8]naphthyridines. Finally, reaction of compound 1 with 6-aminouracils as cyclic enamines yielded pyrimido[4,5-b][1,8]naphthyridines. Some of the synthesized products showed noteworthy antimicrobial efficiency against all types of microbial strains. Structures of the produced compounds were established using analytical and spectroscopic tools.