THREE-COMPONENT SYNTHESIS OF NEW SUBSTITUTED BIS[2-IMINO-3-(SUBSTITUTED)-4-PHENYL-3H-THIAZOLE] DERIVATIVES AND EVALUATION OF THEIR ANTIBACTERIAL ACTIVITY (original) (raw)
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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 .
Synthesis and Antimicrobial Profile of Some Newer Heterocycles Bearing Thiazole Moiety
SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY, 2012
Various substituted acetophenones on treatment. with iodine and thiourea yielded 2-amino-4-( substituted-phenyl)-thiazole, which on further treatment with acetic anhydride generated N-(4-(substituted phenyl)thiazol-2-ylacetamide(1-5). All the synthesized compounds were characterized by their respective FTIR, 1H NMR, and mass data. Synthesized compounds (l, 2, 3, 4, 5) when subjected to investigation for their antimicrobial activities i.e. antibacterial and antifungal studies against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Aspergillus flavus, and Aspergillus fumigatus by disk diffusion method, revealed that compound 2 deemed to be most potent with the largest zone of inhibition.
Facile Regioselective Synthesis of Novelbis-Thiazole Derivatives and Their Antimicrobial Activity
Archiv der Pharmazie, 2013
The design and synthesis of several new bis-thiazoles 4a-h serving as bis-drugs in comparison with monoheterocyclic analogs are described. These bis-drugs present superior medicinal and pharmacological activities against both gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive (Micrococcus luteus and Bacillus subtilis) bacteria, which are in general more sensitive to compounds with higher hydrophobicity. Compounds with higher hydrophobicity (4d and 4h) exhibited some activity against the gram-negative bacteria.
European Journal of Medicinal Chemistry, 2012
Some new 5-(4-(4-X-phenylsulfonyl)phenyl)-4-(R)-2H-1,2,4-triazol-3(4H)-thiones 4a,b; 5a,b and 5-(4-(4-X-phenylsulfonyl)phenyl)-N-(R)-1,3,4-thiadiazol-2-amines 6a,b; 7a,b were obtained by cyclization of new N 1 -[4-(4-X-phenylsulfonyl)benzoyl]-N 4 -(R)-thiosemicarbazides 2a,b; 3a,b (X ¼ H, Br). The 1,2,4triazoles were synthesized by intramolecular cyclization of acylthiosemicarbazides, in basic media. On the other hand, 1,3,4-thiadiazoles were obtained from same acylthiosemicarbazides, in acidic media. These new intermediates from thiosemicarbazide class were afforded by the reaction of 4-(4-X-phenylsulfonyl)benzoic acids hydrazides (X ¼ H, Br) 1a,b with 4-trifluoromethoxyphenyl or 3,4,5trimethoxyphenyl isothiocyanate. The newly synthesized compounds were characterized by IR, 1 H NMR, 13 C NMR, MS and elemental analysis. All the new compounds were screened for their antimicrobial activity against some bacteria (Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 13061, Escherichia coli ATCC 25922, Enterobacter cloacae ATCC 49141, Acinetobacter baumannii ATCC 19606 and Pseudomonas aeruginosa ATCC 27853) and yeasts (Candida albicans ATCC 90028 and Candida parapsilosis ATCC 22019).
2010
In the search for new benzimidazole derivatives with high antibacterial activity and for which bacterial resistance is low, novel ethyl 2-(alkoxyimino)-2-[1-(4-morpholinocarbonylmethyl)-1H-benzimidazol-2-yl]acetates have been synthesized by multi-step reactions and characterized by 1 H NMR, IR, and ESI-MS analysis. The compounds were evaluated for in-vitro antibacterial activity against Escherichia coli and Staphylococcus aureus. The results revealed that four of the compounds had excellent bioactivity against S. aureus, with IC 50 values of 12.72-26.58 lg/mL, even better than that of the control agent (levofloxacin hydrochloride).
Design, Synthesis, and Pharmacological Evaluation of Some Novel Bis-Thiazole Derivatives
Asian Journal of Pharmaceutical and Clinical Research
Objective: A series of substituted 5,2-bis-thiazoles derivatives were synthesized by Hantzsch reaction and evaluated in vitro for antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. Methods: 2-(4-(benzyloxy)phenyl)-4-methylthiazole-5-carbothioamide were synthesized and allowed to react with various α-haloketones to give 5,2-bis-thiazoles, i.e., 2-(4-(benzyloxy)phenyl)-4-methyl-5-(4-substituted thiazol-2-yl)thiazole derivatives in excellent yield. The synthesized compounds were characterized by spectroscopic methods as well as elemental analyses. They were screened for their antimicrobial activity using the agar diffusion method.Result: Literature survey reveals that the synthesis of 2-(4-(benzyloxy)phenyl)-4-methyl-5-(4-substituted thiazol-2-yl)thiazole, i.e., (5,2-Bis-thiazoles) derivatives (10a-e) was not reported. The entire compound exhibited mild to moderate antimicrobial activity.Conclusion: The antimicrobial ...
Some novel 1,3,4-thiadiazole [5-8] and 1,2,4-triazole [9-12] derivatives carrying amino acid moiety were synthesized starting from L-methionine. 1,3,4-Thiadiazole and 1,2,4-triazole scaffolds were prepared by cyclocondensation of the corresponding thiosemicarbazide and finally converted to their thiourea derivatives. Structures of the synthesized compounds [4-12] were confirmed by IR, 1 H-NMR and 13 C-NMR spectral data and elemental analysis. Synthesized compounds were evaluated for their antiviral and antibacterial activity. Of the screened compounds, N-{3-(methylsulfanyl)-1-[5-(phenylamino)-1,3,4-thiadiazole-2-yl]propyl}benzamide [5] was identified as the most potent inhibitor of Influenza A H3N2 virus with an EC 50 value of 31.4 μM, which serves as a lead compound for prospective development. The antituberculosis activity screen of the synthesized compounds revealed 1-[4-(4-chloro-(3-trifluoromethyl)phenyl]-3-[3-(methylsulfanyl)-1-(4-phenyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazole-3-yl)propyl]thiourea [12] as the most active compound against M. tuberculosis H37Rv strain (MIC : 30.88 µM) but the compound proved not selective.
2013
We have synthesized a series of α bromoketones& thiadiazole with various benzimidazoles. The compounds were confirmed by physical parameters (solubility, melting point), chromatographic methods (TLC) and at last spectroscopic methods (IR, NMR). Since our titled compounds are known to possess antimicrobial activity, the compounds were screened for their antibacterial and antifungal activity by cup-plate method. All the benzimidazole substituted thiadiazole derivatives (B1,B2,B and B4) showed significant activities compared to the standards ciprofloxacin for significant activity against E.coli,andS.aureusat 50, 100,300 and 500 mcg/ml and Miconazole significant activity againstCandida albicansat 50, 100, 300,500 mcg/ml. The benzimidazole showed mild antibacterial activities and significant antifungal activities.
Synthesis, Characterization and Antimicrobial Activities of Some Thiazole Derivatives
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