فهرست مطالب jabbar khalafy

Antimicrobials are one of the extremely important categories of drugs for the treatment, control, and prevention of microbial diseases, but the development of drug resistance against clinically used antibacterial agents has increased the demand for the design and synthesis of new drugs. We have previously synthesized new series of 10-substituted-5H-naphtho[1,2-e][1,2,4]triazolo[3,4-b] [1,3,4]thiadiazin derivatives (4a-4f). In this study, we evaluated the antimicrobial activity of these derivatives against some pathogenic microorganisms.

The reaction of 2-bromo-1,4-naphthoquinone with 4-amino-5-aryl-4H-1,2,4-triazole-3- thiols in ethanol at 50 ̊C gave the corresponding 2-[(4-amino-5-aryl-4H-1,2,4-triazol-3 yl)thio] naphthalene-1,4- diones. Moreover, their treatment with EtOH/HCl under reflux conditions produced 10-substituted-5H-naphtho[1,2-e][1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-5- ones through intramolecular cyclization. The well agar diffusion and agar dilution methods were used during the preliminary evaluation of antimicrobial activity for the determination of inhibition zone (IZ) and minimum inhibitory concentration (MIC).

Seven tetracyclic heterocyclic ring systems were produced under reflux conditions. The structures of all the products were identified by their FT-IR, 1H, and 13C NMR spectral data and by elemental analysis. The results revealed that the antibacterial activity of compounds 4a, 4b, 4c, and 4d are higher than that of the others, and compounds 4d, 4a, 4e, and 4f exerted the greatest effect on fungal samples.

All synthesized compounds exhibited promising antibacterial and antifungal activity. In this study, compounds 4a-4g exhibited highly potent antimicrobial activity and acceptable selectivity index against Staphylococcal and Candida infections.

A regioselective method for synthesis of pyrido[3,4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3,4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC. A regioselective method for synthesis of pyrido[3,4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3,4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC. A regioselective method for synthesis of pyrido[3,4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3,4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC. A regioselective method for synthesis of pyrido[3,4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3,4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC.

Carbon nanotubes (CNTs) have been extensively explored for adsorption applications due to their well-defined cylindrical hollow structure, large surface area, high aspect ratios, hydrophobic wall, and easily modified surfaces. In the present work, a poly Schiff-base was synthesized with capability to remove the dye pollutant from aqueous solutions. For this propose, firstly, multi-walled carbon nanotube (MWCNT) was modified with melamine, then the melamine-modified MWCNT was further reacted with 3-pyridinecarboxaldehyde to synthesize the final poly Schiff-base. The prepared adsorbent was employed to assess the removal of the dye pollutants from aqueous solutions and Congo red (CR) was selected as typical dye. Different adsorption parameters such as pH, adsorbent amount, initial concentration of the dye, and contact time were investigated and optimized. By adjusting these parameters, the adsorption percentage reached to the value of 92%. Moreover, the adsorption isotherms were studied and fitted with the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. The kinetic studies were carried out by using the Lagergren pseudo-first-order and the Ho pseudo-second-order equations. The adsorbent was also characterized by FT-IR, TGA, and SEM techniques.

In this research study, one-pot, four-component reaction of 3-aryl-3-oxopropanenitriles, 1-aryl-3-methyl-1H-pyrazol-5 (4H) one, arylglyoxals and ammonium acetate using green solvent systems and different catalysts under the reflux conditions afforded a series of the corresponding 4-aroyl-3-methyl-1,6-diaryl-1H-pyrazolo [3,4-b] pyridine-5-carbonitrile derivatives. The best yields (70-85%) were obtained using the metal oxide silica based-matal bifunctional LDH (layered double hydroxide) as a magnet nanocatalyst in EtOH/H2O (1:1) under the reflux conditions. This protocol provided mild reaction conditions, good yields, simple workup procedure, easy preparation of nanocatalyst and, products to structurally diverse bicyclic pyrazolo [3,4-b] pyridines, demonstrating biological and pharmacological activities.

Antimicrobial resistance is a serious threat to global public health. The overuse and misuse of antibiotics are the most important contributing factors to development of antibiotic resistance. Thus, there is an urgent need to identify and discover new compounds against drug-resistant microorganisms. We have previously synthesized new series of 3-substituted 5H-(1,2,4)triazolo(3',4':2,3) (1,3,4)thiadiazino(5,6-b)quinoxaline derivatives (4a-4f). Here, we evaluate the antimicrobial activity of these derivatives against methicillin-resistant Staphylococcus aureus, S. aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Candida tropicalis and Candida krusei.      

The agar well diffusion and agar dilution methods were used for determining inhibition zone diameter and minimum inhibitory concentration during preliminary evaluation of antimicrobial activity.       

All synthesized compounds exhibited antibacterial and antifungal activity against the tested microorganisms.       

Our findings indicate the antimicrobial potential of the six novel synthetic triazolo thiadiazin quinoxaline compounds.

Multicomponent condensation of 1-naphthol, malononitrile, and arylglyoxals in the presence of Mg-Al hydrotalcite under solvent-free MicroWave (MW) conditions gave a new series of 2-amino-4-aroyl-4H-benzo[h]chromene-3-carbonitriles in high yields (70-89%). The structure of all products was elucidated by their FT-IR, 1H-NMR, 13C-NMR spectral data and microanalysis.

This review provides an overview of the recent literature on application of arylglyoxals the synthesis of pyrrolo[2,3-d]pyrimidines via multicomponent reactions in the period of 2008–2018. 1,2-Dicarbonyl compounds are attractive precursors for synthesis of various heterocyclic compounds, and arylglyoxals are frequently applied in synthesis of various organic compounds, and in particular of pyrrolo[2,3-d]pyrimidines derivatives, which are important due to their biological and pharmaceutical activities.

A green approach to synthesis of the polyfunctionalized pyrazole [4′,3′:5,6]pyrido[2,3-d] pyrimidines derivatives was successfully achieved via one-pot, four component reactions of β-aminocrotonitrile, phenyhydrazine, arylglyoxals, barbituric acid derivatives in the presence of TEA (Triethylamine) as a catalyst in water under the reflux conditions. This protocol provided mild reaction conditions, short reaction times, high yields, low cost, easy isolation of products and possible biological, and pharmaceutical activities.

A new and improved protocol for the synthesis, in good to excellent yields, of acridine-1,8(2H,5H)-diones is described, involving a one-pot, three component reaction of dimedone, arylglyoxals, and ammonium acetate in water under microwave irradiation.

The NMR spectra of azo dyes, 5-arylazobarbituric (5a-g), 5-arylazo-1,3-dimethylbarbituric (6a-g) and 5-arylazothiobarbituric acids (7a-g) were studied in DMSO-d6 in different concentrations. An intramolecular hydrogen bond was observed and indicating that the hydrazone forms is mostly predominant. The peak of the hydrazone proton was severely broadened and its chemical shift appeared at down field due to intramolecular hydrogen bond. Existence of nitro group at ortho-position on phenyl ring caused the chemical shift value of the proton of hydrazone form in 5a-7a to be more deshielded than other hydrazone protons in 5bg− 7b-g due to bifurcated intramolecular hydrogen bond and anisotropic ring-current effect. Dyes 6 shows two tautomers in NMR time scale at low concentration in DMSO-d6.

Several 10-substituted anthralins were readily prepared. Their oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone gave the corresponding novel heteroatomic systems. All derivatives were fully characterized by IR, Mass and 1HNMR Spectroscopy.