Fused Heterocycles : Synthesis of Some New Imidazothiazoles (original) (raw)
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Antibiotics
Fifteen 4-methyl-1,2,3-thiadiazole-based hydrazone derivatives 3a–d and sulfonyl hydrazones 5a–k were synthesized. They were characterized by 1H-NMR, 13C NMR, and HRMS. Mycobacterium tuberculosis strain H37Rv was used to assess their antimycobacterial activity. All compounds demonstrated significant minimum inhibitory concentrations (MIC) from 0.07 to 0.32 µM, comparable to those of isoniazid. The cytotoxicity was evaluated using the standard MTT-dye reduction test against human embryonic kidney cells HEK-293T and mouse fibroblast cell line CCL-1. 4-Hydroxy-3-methoxyphenyl substituted 1,2,3-thiadiazole-based hydrazone derivative 3d demonstrated the highest antimycobacterial activity (MIC = 0.0730 µM) and minimal associated cytotoxicity against two normal cell lines (selectivity index SI = 3516, HEK-293, and SI = 2979, CCL-1). The next in order were sulfonyl hydrazones 5g and 5k with MIC 0.0763 and 0.0716 µM, respectively, which demonstrated comparable minimal cytotoxicity. All compo...
ACTA Pharmaceutica Sciencia, 2017
Indoles, especially 1H-indole-2,3-dione (isatin) are the most prevalent heterocyclic scaffolds which have a broad spectra of medical applications such as anti-HIV, antiviral, anti-tumor, antifungal, antiangiogenic, anti-convulsant, and antiparkinsonian activity 6-8. In particular, antituberculotic activity of various indole derivatives 9-14 and isatin derivatives 15-22 have attracted attention. The syn-ABSTRACT A series of 3-[(4-aryl-2-thiazolyl)hydrazone]-1H-indol-2,3-dione derivatives (2af) were designed and synthesized using isatin as starting material. The obtained thiazole compounds were screened to investigate their antituberculosis activity against Mycobacterum tuberculosis H37RV (ATCC 27294). Among them, two compounds 2c and 2d were displayed antitubercular potential twofold greater than standard drugs.
2015
Abstract: In this study, some novel N2-arylidene/cycloalkylidene-(6-(4-nitrophenyl)imidazo[2,1-b]thiazol-3-yl)acetic acid hydrazides (2a-d) were synthesized from (6-(4-nitrophenyl)imidazo[2,1-b]thiazol-3-yl)acetic acid hydrazide (1). The newly synthesized compounds were characterized by IR, 1H NMR, mass and elemental analysis. Their antibacterial and antifungal activities were evaluated against S. aureus ATCC 29213, P. aeruginosa ATCC 27853, E. coli ATCC 25922, C. albicans ATCC 10231, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, T. mentagrophytes var. erinacei NCPF 375, M. gypseum NCPF 580 and T. tonsurans NCPF 245. N2-Cyclohexylidene-(6-(4-nitrophenyl)imidazo[2,1-b]thiazol-3-yl)acetic acid hydrazide (2c) and N2-(3-methylcyclohexylidene)-(6-(4-nitrophenyl)imidazo[2,1-b]thiazol-3-yl)acetic acid hydrazide (2d) showed the highest antibacterial activity. Particularly 2c showed the highest antifungal activity against tested fungi. Key words: Imidazo[2,1-b]thiazole, arylidene/cycloalk...
Synthesis and antimycobacterial activity of new imidazo[2,1-b]thiazole derivatives
European Journal of Medicinal Chemistry, 1994
In the present investigation 4-hydroxy-3-methylacetophenone on condensation with various aromatic aldehydes in methanolic KOH solution yielded the corresponding chalcones (C I -C XI ). These chalcones were further reacted with hydrazine hydrate in ethanol which led to the formation of pyrazoline derivatives (H I -H XI ). The newly synthesized heterocyles were characterized on the basis of their chemical properties and spectroscopic data. All newly synthesized compounds were evaluated for their antimycobacterial activities against Mycobacterium tuberculosis H37 Rv .
Journal of Heterocyclic Chemistry, 2016
Novel 6-(1,2,3-triazol-4-yl)-5-[(2-(thiazol-2-yl)hydrazono)methyl]imidazo[2,1-b]thiazoles 7, 9a-d, and 11 were prepared by reaction of thiosemicarbazone 5a,b with either hydrazonoyl chloride 6, phenacylbromides 8 or 2-bromo-1-(5-methyl-1-p-tolyl-1H-1,2,3-triazol-4-yl)ethanone 10 respectively. The new products were tested for their antimicrobial activities using 96-well micro-plate assay, and compound 7 showed excellent antibacterial activities compared with Vancomycine (reference drugs), while compounds 5b and 9c exhibited good results against yeast. The minimum inhibitory concentration (MIC) was determined, and compound 7 showed the lowest MIC against Gram positive bacteria while compound 5b showed the lowest MIC against yeast.
Medicinal Chemistry Research, 2017
The increase in antibiotic resistance due to multiple factors has warranted the need for search of new compounds which are active against multidrug resistant pathogens. In this context a small focused library of thiosemicarbazide derivatives of 2-arylthiazole-4-carbaldehyde, 4-methyl-2-arylthiazole-5-carbaldehyde and 1-(4-methyl-2arylthiazol-5-yl) ethanone, (5a-l) has been synthesized. The title compounds were screened for inhibitory activity against Mycobacterium tuberculosis H37Ra (ATCC 25177) and Mycobacterium bovis Bacille Calmette Guerin (ATCC 35743) strains. The synthesized compounds, 5a-l were further assayed for their cytotoxic activity against the two human cancer cell lines, HeLa and human colon carcinoma 116 cell lines and showed no significant cytotoxic activity against these two cell lines at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antibacterial activity against Gramnegative bacteria, Escherichia coli, Pseudomonas flurescence and Gram-positive bacteria, Staphylococcus aureus, Bacillus subtilis. Most of the synthesized compounds showed moderate activity against fungal strain Candida albicans. This study provides valuable directions to our ongoing endeavor of rationally designing more potent antimycobacterial agent.
Journal of Heterocyclic Chemistry, 2010
3-(4-methyl-2-phenylthiazol-5-yl)-2-phenylazo-1H-pyrido[2,3-b]pyrazine derivatives were synthesized via reaction of 2-(4-methyl-2-phenyl-1,3-thiazol-5-yl)-2-oxo-N-arylethanehydrazonoyl bromide with each of 2-aminopyrimidine, 2-aminopyridine, 3-aminopyrazoles, 2-amino-4-phenylthiazole, o-phenylenediamine, o-aminothiophenol, o-aminophenol, or 2, 3-diaminopyridine, respectively. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible. The entire newly synthesized compounds are tested toward different microorganisms.
Synthesis and Antituberculosis Activity of New Hydrazide Derivatives
Archiv Der Pharmazie, 2008
The increasing clinical importance of drug-resistant mycobacterial pathogens, especially Mycobacterium tuberculosis, has lent additional urgency to microbiological research and new antimycobacterial compound development. For this purpose, new hydrazide derivatives of imidazo[1,2-a]pyridine were synthesized and evaluated for antituberculosis activity. The reaction of 2-[(2-carboxyimidazo[1,2-a]pyridine-3-yl)sulfanyl]acetic acid hydrazide with various benzaldehydes gave N-(arylidene)-2-[(2-carboxyimidazo[1,2-a]pyridine-3-yl)sulfanyl]acetic acid hydrazide derivatives. The chemical structures of the compounds were elucidated by IR, 1H-NMR, FAB-MS spectral data and elemental analysis. Antituberculosis activities of the synthesized compounds were determined by broth microdilution assay, the Microplate Alamar Blue Assay in BACTEC 12B medium. The results were screened in vitro, using the BACTEC 460 Radiometric System against Mycobacterium tuberculosis H37Rv (ATCC 27294) at 6.25 μg/mL; the tested compounds showed significant inhibition.
Heterocyclic Communications, 2015
Synthesis, characterization, and investigation of antimicrobial activities of nine novel imidazolylthiazoles are presented. Their structures were determined using 1 H NMR, 13 C NMR, and elemental analysis. Compounds 3e and 3i show very strong or strong bacteriostatic or bactericidal activity [minimal bactericidal concentration/ minimal inhibitory concentration (MIC) = 2-64] against Staphylococcus spp. (MIC = 7.81-15.62 μg/mL), Micrococcus luteus ATCC 10240 (MIC = 1.95-3.91 μg/mL), and Bacillus spp. (MIC = 3.91-15.62 μg/mL). Compounds 3e and 3i also show the highest fungicidal effect (minimal fungicidal concentration/MIC = 2-4) against reference strains of fungi belonging to Candida spp. with MIC ranging from 3.91 to 31.25 μg/mL.