Synthesis and Characterization of New Heterocyclic Compounds Derived from 2-Aminopyridine (original) (raw)
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Medicinal Chemistry Research, 2012
The basic nucleus 4-amino-5-[4-(methylsulfonyl)benzyl]-2,4-dihydro-3H-[1,2,4]-triazole-3-thione was prepared by cyclisation of potassium dithiocarbazinate with hydrazine hydrate using ethanol as solvent under reflux condition. The compound which has been synthesized successfully was subjected to addition reaction with different aldehydes to synthesize Schiff bases. The compounds were confirmed by spectroscopic methods (IR, NMR, and Mass). In order to ascertain the pharmaceutical application, the selective pharmacological screening of the derivatives was carried out according to the standard procedures. The compounds were screened for their cytotoxic activity and antimicrobial activity.
Synthesis of Some New Schiff Bases Derived From Symmetrical 4- Amino-1,2,4-Triazole
In this paper the synthesis of some Schiff bases, namely 4-(substituted benzylidene amino)-4H-1,2,4-triazoles (3a-g) derivatives by the reaction of symmetrical substituted 4-amino-1,2,4-triazole (2) and appropriate substituted ketons in presence of acetic acid. The synthesized compounds were characterized on the bases of their physical properties and spectroscopic data. Some of these compounds were tested for biological activities as antibacterial and antifungal agents and showed a significance to moderate activity.
PubMed, 2011
The basic nucleus 4-(amino)-5-phenyl-l-4H-1,2,4-triazole-3-thiol was prepared by cyclisation of potassium dithiocarbazinate with hydrazine hydrate using water as solvent under reflux condition for 3-4 h. The compound which has been synthesized successfully was subjected to addition reaction with different aldehydes to synthesize Schiff bases. The compounds were confirmed by physical parameters (solubility, melting point), chromatographic methods (TLC) and at last spectroscopic methods (IR, NMR, and Mass). In order to ascertain the pharmaceutical application, the selective pharmacological screening of the derivatives was carried out according to the standard procedures. The compounds were screened for their antianxietic activity by elevated plus maze method, antidepressant activity by forced swim test. Among the synthesized compounds, the Schiff bases of benzaldehyde (5e), furfuraldehyde (5d) and 2,4-dichloro benzaldehyde (5a) showed extremely significant activities. Results indicate that these compounds may be potential candidates for managing CNS disorders. However further studies are required to substantiate the same which are underway in our lab.
Structure investigations of Schiff bases derived from 3-amino-1H-1,2,4-triazole
Journal of Molecular Structure, 2019
In the present paper, twelve Schiff bases derived from 3-amino-1H-1,2,4-triazole (ATz) and various benzaldehydes, and salicylaldehydes were synthesized. The 1 H, 13 C, and 15 N NMR data are discussed in relation to the structure of ATz and its imine products. In addition, X-ray, ATR-FTIR, and UV-Vis analytical techniques are used for structure elucidation of ATz-based Schiff bases. It was found that the starting material, 3-amino-1H-1,2,4-triazole, exists as tautomeric mixture of three forms (Graphical Abstract) in solution, whereas in the solid state (13 C and 15 N CPMAS data) potentially tautomeric proton is located on nitrogen atom traditionally marked as N-2 (Graphical Abstract, 2N-H structure). All investigated Schiff bases derived from salicylaldehydes exist in both phases as tautomeric equilibrium mixtures, where enol-imine forms are dominated structures. The positions of those equilibria only very slightly depend on substituents in phenol ring. Generally, the contributions of keto-amine forms in the solid state are higher comparing with DMSO solutions.
Advances in Biological Chemistry, 2016
Four new Schiff bases with promising anticancer activity have been synthesized from 4-amino-3,5-dimethyl-1,2,4-triazole and di-pyridyl-aldehydes. Structures have been established by various spectroscopic methods. The compounds were tested in vitro to study their cytotoxicity and anti-oxidative activity in human lung carcinoma (A549), breast carcinoma (BT549), prostate adenocarcinoma (PC3) and mouse preadipocytes (3T3-L1) cells. Compound 1 was found to increase Glutathione (GSH) level slightly in all four cell lines. Compound 4 showed better selectivity and cytotoxicity against both BT549 and A549 cells compared to the anticancer drug tamoxifen. With the exception of compound 4 which reduced GSH levels in A549 and BT549, all other compounds maintained GSH levels in comparison to their respective controls.
A series of new Schiff bases, namely 4-(substituted benzylidene amino)-4H-1,2,4-triazoles (5a-j) derivatives were synthesized by the reaction of symmetrical substituted 4-amino-1,2,4-triazole (4) and appropriate substituted aromatic aldehydes in presence of acetic acid. The synthesized imines were characterized on the bases of their physical properties and spectroscopic data. Some of these compounds were tested for biological activities as antibacterial and antifungal agents and showed a significance to moderate activity.
This research involves synthesis some of new tetrazole, imidazolinone, thiazolidinone, and oxazepine derivatives. The first step includes formation Schiff bases (1-5) from condensation N-[(4-aminophenyl) carbamothioyl] benzamide with different aromatic aldehydein the presence of glacial acetic acid in DMF as a solvent. Four route with different reagents used for the cyclization of the prepared Schiff bases by reagent (sodium azide, 2-amino acetic acid, 2-mercapto acetic acid and phthalic anhydride) to form tetrazole (6-10), imidazolinone (11-15), Thiazolidinone (16-20), oxazepine(21-25) derivatives respectively. The structure of newly synthesized compounds were identified by spectral methods their [FTIR, and some of them by 1HNMR, 13C-NMR] and measurements some of its physical properties and some specific reactions. The chemical structures of synthesized compounds were well characterized by 1HNMR, 13CNMR, FT-IR and TLC. Also, the effects of prepared compounds in some of strains of bacteria were studied.
Acta Pharmaceutica, 2015
Triphenylimidazol-2-yl-thio)butyric acid hydrazide (3) was obtained via alkylation of 1,4,5-triphenylimidazol-2thiol (1) with ethylbromobutyrate, followed by addition of hydrazine hydrate. Treatment of acid hydrazide 3 with carbon disulfi de in an ethanolic potassium hydroxide solution gave the intermediate potassium dithiocarbazinate salt, which was cyclized to 4-amino-5-[(1,4,5-triphenylimidazol-2-yl)thiopropyl]-2H-1,2,4-triazole-3-thione (4) in the presence of hydrazine hydrate. Condensation of compound 3 with alkyl/arylisothiocyanate aff orded the corresponding 1-[4-(1,4,5-triphenylimidazol-2-ylthio)butanoyl]-4-alkyl/arylthiosemicarbazides (5-7), which upon refl uxing with sodium hydroxide, yielded the corresponding 1,2,4-triazole-3-thiols 8-10. Under acidic conditions, compounds 4-6 were converted to aminothiadiazoles 11-13. Moreover, the series of Schiff bases 14-18 were synthesized from the condensation of compound 3 with diff erent aromatic aldehydes. The newly synthesized compounds were characterized by IR, 1 H NMR, 13 C NMR and mass spectral analyses. They were also preliminarily screened for their antimicrobial activity.
Synthesis And Biological Evaluation of Some New Schiff base 1,2,4-Triazole Derivatives
International Journal of Pharmaceutical Chemistry, 2017
A series of substituted 1,2,4-Triazole derivatives were synthesized, and their anticonvulsant activity and antimicrobial activity were evaluated which include the MES model and by Cup-plate method. However, further studies need to be carried out to ascertain the precise mechanism of action of anticonvulsant activity of these molecules. The compounds 4-[1-(2-Bromo-phenyl)-ethylideneamino]-5-pyridin-3-yl-2,4-dihydro[1, 2, 4] triazole-3-thione (SB-1) and 4-[1-(4-Fluoro-phenyl)-ethylideneamino]-5-pyridin-3-yl-2,4-dihydro[1, 2, 4] triazole-3-thione (SB-2) showed significant anticonvulsant activity and antibacterial activity against Escherichia coli.
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2014
Schiff Bases of 5-(2-phenoxypyridin-3-yl)-1, 3, 4-thiadiazol-2-aminederivatives 6(a-h) have been synthesized with different aromatic aldehyde and tested for in vitro anticancer activity; the 1, 3, 4-thiadiazole derivatives were prepared by the reaction ofthiosemicarbazide, phosphorousoxychloride and aromatic acids. The synthesized final Schiff base compounds were purified by column-chromatography and the structures of the titled Schiff bases were elucidated by IR, 1 H NMR and LCMS spectral measurements. Three different cell lines namely Hela, Hep-G2 and MCF7 are used for the present study. The compounds tested were, in most of cases shows cytotoxic effect but, only one compound showed good activity on breast carcinoma cell line having IC50 = 2.28 μg/ mL.