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Triazole derivatives constitute an important group of heterocyclic compounds have have been the subject of extensive study in the recent past. These compounds have shown a wide range of biological and pharmacological activities. In this work, new fused tricyclic 1-(3-nitrophenyl)-5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1,5]-benzodiazepines have been synthesized by the thermal cyclization of N'-(2,3-dihydro-1H-1,5-benzodiazepin-4-yl)-3- nitrobenzohydrazides. After screening ethanol, toluene and 1-butanol as solvents, butanol-1 was found to be the best choice for the cyclization reaction in order to obtain the highest yields of tricyclic derivatives. The chemical structures of the synthesized compounds were elucidated by the analysis of their IR, 1H- and 13C-NMR spectral data. For tentative rationalization of the reaction processes, the global and local reactivity indices of certain compounds, taking part in the reaction pathway, were assessed by means of quantum mechanical calculations using the conceptual density functional theory (DFT) approach. This work could be useful for the synthesis of new heterocyclic compounds bearing a fused triazole ring. [ABSTRACT FROM AUTHOR]

The series of novel N-R-2-[(3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)thio]acetamides with thiazole and thiadiazole fragments in a molecule were obtained by alkylation of potassium salts 1.1-1.4 by N-hetaryl-2-chloro-acetamides and by aminolysis of activated acids 2.1-2.4 with N,N'-carbonyl-diimidazole (CDI). The structures of compounds were determined by IR, 1H NMR, MS, and EI-MS analysis. The results of cytotoxicity evaluated by the bio-luminescence inhibition of bacterium Photobacterium leiognathi, Sh1 showed that the compounds have considerable cytotoxicity. The synthesized compounds were tested for anticancer activity in NCI against 60 cell lines. Among the highly active compounds 3.1, 3.2, and 6.5, 2-[(3-methyl-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)thio]-N-(1,3-thiazol-2-yl)acetamide (3.1) was found to be the most active anticancer agent against the cell lines of colon cancer (GI50 at 0.41-0.69 μM), melanoma (GI50 0.48-13.50 μM), and ovarian cancer (GI50 0.25-5.01 μM). The structure-activity relationship (SAR-analysis) was discussed. [ABSTRACT FROM AUTHOR]

A simple strategy for the synthesis of the hitherto unreported 3-arylazo-4- phenyl- [1,2,4]triazepino[2,3-a]quinazoline-2,7(1H)-diones is described. Spectral data indicated that the studied compounds exist predominantly in the hydrazone tautomeric form. The antimicrobial activity of the newly synthesized compounds was also evaluated. The results indicated that some of these compounds have moderate activity towards bacteria. [ABSTRACT FROM AUTHOR]

Microwave-assisted synthesis of some novel compounds, namely, 3-(2-methyl-1H-indol-3-yl)-6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a,b was accomplished via bromination of 2-methyl-3-[4-(arylideneamino)-5-mercapto-4H-[1,2,4]triazol-3-yl]-1Hindoles 3a,b. Also, new [1,3,4]thiadiazoles 12a,b, [1,2,4]triazoles 15a,b and [1,3,4]oxadiazoles 19a,b, with indole moieties, were prepared by cyclization of 1-[(2-methyl-1H-indole)-3-carbonyl]thiosemicarbazides 8a,b under microwave irradiation using different reaction conditions. Moreover, reaction of acid hydrazide 7 with ethyl 2-(N-phenylhydrazono)-3-oxobutanoate (20) gave the respective phenylhydrazonopyrazole derivative 21 under the reaction conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data (IR, ¹H-NMR, 13C-NMR, MS). The antifungal and antibacterial activities of the new products were also evaluated. [ABSTRACT FROM AUTHOR]

Arylhydrazonomalononitriles 1a,b react with phenylhydrazine to yield amidrazones 2a,b that cyclize to give 2-aryl-5-phenylhydrazono-2,5-dihydro-[1,2,4]-triazine-6-carbonitriles 5a,b upon reaction with dimethylformamide dimethylacetal (DMFDMA). Refluxing 5a,b in glacial acetic acid resulted in the formation of the pyrazolo-1,2,4-triazines 6a,b. Compounds 6a,b were also formed upon treatment of 3-amino-4-phenylhydrazono-1-phenyl-2-pyrazolin-5-ones 7a,b with DMFDMA. Reacting these triazinyl arylhydrazononitriles 5a,b with hydroxylamine hydrochloride in ethanolic sodium acetate afforded amidrazones 8a,b that are readily cyclized in refluxing dimethylformamide into [1,2,4]triazino[1,2,3]triazines 10a,b. [ABSTRACT FROM AUTHOR]