Azo-Hydrazone Tautomerism and Antimicrobial activity of New substituted Imidazolines and Perimidines

Two new series of 2-{1-[(substitutedphenyl)-hydrazono]-2-oxo-2-phenyl-ethyl}-5,5-diphenyl-3,5-dihydro-imidazol-4-one  and  (1H-Perimidin-2-yl)-[(substitutedphenyl)-hydrazono]-acetic acid ethyl ester were prepared by coupling the diazonium salt of aniline and its derivatives with 2-(2-oxo-2-phenyl-ethylidene)-5,5-diphenyl-imidazolidin-4-one or ethyl 3-dimethylamino-2-(1H-perimidin-2-yl)-propenoate in ethanolic sodium hydroxide solution. The structures of all the newly synthesized compounds were confirmed by spectral (IR, 1H NMR, mass) spectra , and X-ray crystallographic and elemental analyses. Also, the azo-hydrazone tautomerism of these compounds was discussed. In addition, all the newly synthesized compounds were screened for their antibacterial and antifungal activity and the results obtained indicated that some of these compounds exhibited excellent activity

Exocyclic enaminones as building blocks for synthesis of bioactive polyheterocyclic compounds

The reaction of exocyclic enaminones namely, 2-(dimethylaminomethylene)-3,4-dihydro-2H-naphthalen-1-one,  3-(dimethylaminomethylene)-thiochroman-4-one and 2-(dimethyl-aminomethylene)-indane-1,3-dione, each with heterocyclic diazonium salts afforded the respective hydrazones which undergo either in situ dehydrative cyclization or cyclized by heating with acetic acid to give polycyclic compounds. The structure of all the newly synthesized products were confirmed by elemental and spectral (IR, IH NMR, Mass) data. Also, the biological activity of some of the prepared compounds was tested against some microorganisms and promising results were obtained

Site-selectivite Synthesis and Tautomerism of Arylazo Derivatives of Pyrazolo[3,4-d]pyrimido-[1,6-b][1,2,4]triazine

A simple synthetic strategy is described for synthesis of the hitherto unreported 5-arylazo-1,3-diphenyl-6-substituted-1H-pyrazolo[3,4-d]pyrimido[1,6-b][1,2,4]triazines 5a-n. The spectral data indicated that the studied compounds exist predominantly in the hydrazone tautomeric form 5A. The site-selectivity and mechanism of the studied reactions are discussed

Ethyl (1,3-diphenyl-1H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)acetate

Novel ethyl (1,3-diphenyl-1H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)acetate (5), was prepared via heating of 5-amino-1,3-diphenyl-4,5-dihydro-4-imino-1H-pyrazolo[3,4-d] pyrimidine (1) and diethyl malonate (2) under reflux. The structure of the synthesized compound was assigned on the basis of its elemental analysis, IR, 1H-NMR and mass spectral data

(E)-Ethyl 3-(Dimethylamino)-2-(7,9-diphenyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-2-yl)acrylate

Novel (E)-ethyl 3-(dimethylamino)-2-(7,9-diphenyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-2-yl)acrylate (3A), was prepared via condensation of ethyl (1,3-diphenyl-1H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)acetate (1) and dimethylformamide-dimethylacetal under reflux. The structure of the synthesized compound was assigned on the basis of elemental analysis, IR, 1H NMR and mass spectral data

Ethyl (1,3-diphenyl-1H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)acetate

Novel ethyl (1,3-diphenyl-1H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)acetate (5), was prepared via heating of 5-amino-1,3-diphenyl-4,5-dihydro-4-imino-1H-pyrazolo[3,4-d] pyrimidine (1) and diethyl malonate (2) under reflux. The structure of the synthesized compound was assigned on the basis of its elemental analysis, IR, 1H-NMR and mass spectral data

Ethyl 3-{2-[(3-Methyl-1H-indol-2-yl)carbonyl]­hydrazinylidene}­butanoate

The title compound, ethyl 3-{2-[(3-methyl-1H-indol-2-yl)carbonyl]hydrazinylidene} butanoate (3), was prepared via reaction of 3-methyl-1H-indole-2-carbohydrazide (1) and ethyl 3-oxo­butanoate (2) under reflux. The structure of the synthesized compound was assigned on the basis of elemental analysis, IR, 1H-NMR, mass spectral and X-ray data

Synthesis and Evaluation of the Anti-Microbial Activity of New Heterocycles Containing the 1,3,4-Thiadiazole Moiety

A new series of thiadiazole-enaminones 4 were synthesized via reactions of 5-acetyl-1,3,4-thiadiazoles 3 with dimethylformamide-dimethylacetal (DMF-DMA). The simple phenyl substituted thiadiazole-enaminone 4f was used as a synthetic precursor for the preparation of a wide variety of new heterocyclic compounds, including the 5-substituted-1,3,4-thiadiazole derivatives 5, 6, 11, 12 and 13, which were obtained via reactions of 4f with nitrogen nucleophiles. Also, reactions of enaminone 4f with carbon nucleophiles afforded the respective 1,3,4-thiadiazoles 8a–d. In addition, the results of the antimicrobial activities of thiadiazole-enaminones 4 and their precursors 2 and 3 indicate that some members of this series display promising activities against all tested microorganisms

New Series of Thiazole Derivatives: Synthesis, Structural Elucidation, Antimicrobial Activity, Molecular Modeling and MOE Docking

Based on the extensive biological activities of thiazole derivatives against different types of diseases, we are interested in the effective part of many natural compounds, so we synthesized a new series of compounds containing di-, tri- and tetrathiazole moieties. The formation of such derivatives proceeded via reaction of 2-bromo-1-(4-methyl-2-(methylamino)thiazol-5-yl)ethan-1-one with heterocyclic amines, o-aminothiophenol and thiosemicarbazone derivatives. The structure and mechanistic pathways for all products were discussed and proved based on spectral results, in addition to conformational studies. Our aim after the synthesis is to investigate their antimicrobial activity against various types of bacteria and fungi species. Preceeding such an investigation, a molecular docking study was carried out with selected conformers, as representative examples, against three pathogen-proteins. This preliminary stage could support the biological application. The potency of these compounds as antimicrobial agents has been evaluated. The results showed that derivatives which have di- and trithiazole rings displayed high activity that exceeds the used standard antibiotic

Synthesis and Antimicrobial Activity of Some New 1,3,4-Thiadiazole Derivatives

New series of 1,3,4-thiadiazoles have been prepared via reaction of 1,3,4-thiadiazolenaminones 1 with N-phenyl 2-oxopropanehydrazonoyl chloride (2) in dioxane in the presence of triethylamine. Also, some new heterocycles incorporating 1,3,4-thiadiazole ring were obtained by reaction of 1,3,4-thiadiazolenaminones 1 with nitrogen-nucleophiles like hydrazine hydrate, 3-amino-1,2,4-triazole and 2-aminobenzimidazole. The structure of the new products was established based on elemental and spectral analysis. The relation between the structure of the products and their activity towards some microorganisms was studied and promising results were obtained