Synthesis, Characterization and Antimicrobial Screening of Some Novel 5-(BENZOFURAN-2-YL)-N'-(2- SUBSTITUTED-4-OXOTHIAZOLIDIN-3-YL)-1-PHENYL-1HPYRAZOLE-3-CARBOXAMIDE Derivatives (original) (raw)
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2021
Ethyl 2-(1H-pyrazol-1-yl)acetate (1) was synthesized by the reaction of ethylchloroacetate with 1H-pyrazole, Then compound (1) refluxed with hydrazine hydrate to get 2-(1H-pyrazol-1-yl) acetohydrazide (2). Compound (2) was reaction with appropriate aryl aldehyde to get schiff bases N'-arylidine-2-(1H-pyrazol-1-yl)acetohydrazide derivatives (3a-3f). schiff’s base (3a-3e) were cyclized by reflux with acetic anhydride to get new 1-(5-((1H-pyrazol-1-yl)methyl)-2-aryl-1,3,4-oxadiazol-3(2H)-yl)ethanone derivatives (4a-4e). The structures of the synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR, mass spectra, and elemental analysis data. Synthesized compounds (4a-4e) were evaluated as antibacterial agents against some common pathogenic bacteria Gram-positive (Staphylococcus aureus, Streptococcus pyogenes) and Gram-negative bacteria (Escherichia coli, Psuedomonas aeruginosa). The result of antibacterial activity was compared with standard drugs (Ciprofloxacin and Tetracycl...
International Journal of Pharmacy and Pharmaceutical Sciences, 2015
Objective: Synthesis, characterization and antimicrobial evaluation of some new 1,3-benzothiazolyl pyrazole derivatives. Methods: Aseries of novel2-[3-(substituted phenyl)-4-formylpyrazol-1-yl]-6-chloro benzothiazole derivatives (5a-g) have been synthesized by cyclization through Vilsmeier-Haack reaction on hydrazones (4a-g)of substituted aromatic ketones with 6-chloro benzothiazol-2-yl hydrazine under microwave irradiation in fairly good yields. All the newly synthesized compounds were characterized by IR, 1 Results: The results revealed that all 1,3-benzothiazole pyrazole derivatives(5a-g) were synthesized in satisfactory yields and pharmacologically evaluated for their in vitro antimicrobial activity. All the synthesized compounds were in good agreement with elemental and spectral data. Some of the tested compounds showed good to moderate antimicrobial activity against all tested pathogenic bacterial and fungal strains. HNMR, Mass spectral studies and elemental analysis and were screened for their in vitro antibacterial and antifungal activities also. Conclusion: For the present investigation we have prepared benzothiazole derivatives that are incorporated with pyrazolyl moiety with the hope of potentiating the activity of two such units in the same compound. Compounds 5b, 5c, and 5a showed excellent antibacterial and antifungal activities as compared to reference drugs norfloxacin and ketoconazole.
Synthesis-and-evaluation-of-antimicrobial-activity-of-some-new-heterocyclic-compounds 2
Utility of succinic acid dihydrazide for the synthesis of some new heterocyclic compounds, containing bis-1,3,4-oxadiazole, bis-4-thiazolidinone, bis-5-amino-3-pyrazolone and bis-1,3-dioxo-isoindole. The chemical structures of the prepared compounds have been confirmed by their elemental analysis, FT-IR, 1H NMR and Mass spectra. Investigation of the antimicrobial activity of the compounds was done by the paper disc technique. Some of the tested compounds showed the most favorable antimicrobial activity.
2015
Novel biologically active 2-oxo-3-cyano-4-thiomethyl-10-methoxy-14-oxo-14H-pyrazolo (5,6-d) pyrimido (6,7-c) pyrimido [2,3-b] benzothiazole has been synthesized (III) has been synthesized by the reactions of 3-amino-8-methxy-2H-pyrazolo pyrazolo [3',4'; 4,5] pyrimido [2,1-b] benzothiazole (I) and bismethyl thioacrylate (II) in presence of dimethyl formamide and catalytic amount of anhydrous potassium carbonate. Various derivatives of pyrazolo (5,6-d) pyrimido (6,7-c) pyrimido [2,3-b] benzothiazole (IIIa-f) are prepared by refluxing phenol, o-methyl phenol, p-methyl phenol, aniline, o-methyl aniline, p-methyl aniline. Synthesized compounds are characterized by IR, H 1-NMR spectra. The product (III) has been tested for their antimicrobial activities against gram + ve and gram-ve bacteria
Fourteen(Z)-2-(2-oxo-1-((arylamino)methyl)indolin-3-ylidene)-N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2 yl)hydrazine-1-carboxamides 4a-4n were prepared by treating (Z)-N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)-2-(2- oxoindolin-3-ylidene)hydrazine-1-carboxamide 3 with the aryl amines and formaldehyde. The chemical structures of these compounds were elucidated by their physical constants, spectral data and elemental analysis. These compounds were investigated for their antimicrobial activity against five Gram-positive bacteria, namely, S. aureus, E. faecalis, S. epidermidis, B. subtilis and B. cereus; five Gram-negative bacteria, namely, E. coli, P. aeruginosa, K. pneumoniae, B. bronchiseptica and P. vulgaris; and five fungi, namely, C. albicans, A. niger, A. flavus, M. purpureous and P. citrinum by serial plate dilution method using standard drugs, ofloxacin and ketoconazole, respectively, and their minimum inhibitory concentrations (MICs) were also determined. These compounds showed mild to moderate antibacterial activity against Gram positive as well as Gram negative bacteria. However, they exhibited better antifungal activity. The compound 4j (Ar = 1,2,4-Triazol-4-yl) has been identified as the most promising antifungal agent of this series. There is a possibility that the replacement of triazole ring by other azole ring .e.g. imidazole and 1,2,3-triazole; and / or the presence of halogen substituted coumarin ring may produce promising potent antimicrobial agents that are effective against Gram positive bacteria, Gram negative bacteria and fungi. Keywords: Antibacterial activity, antifungal activity, coumarin, isatin, thiazole.
Chemistry Central Journal, 2018
Background: There is a dire need for the discovery and development of new antimicrobial agents after several experiments for a better resistance of microorganisms towards antimicrobial agents become a serious health problem for a few years in the past. As benzimidazole possess various types of biological activities, it has been synthesized, in the present study, a new series of (5-(3-(1H-benzo[d]imidazol-2-yl)-4-hydroxybenzyl)benzofuran-2-yl)(phenyl)methanone analogs by using the condensation and screened for its in vitro antimicrobial activity and cytotoxicity. Results: The synthesized (5-(3-(1H-benzo[d]imidazol-2-yl)-4-hydroxybenzyl) benzofuran-2-yl)(phenyl)methanone analogs were confirmed by IR, 1 H and 13 C-NMR, MS spectra and HRMS spectral data. The synthesized compounds were evaluated for their in vitro antimicrobial potential against Gram-positive (Bacillus subtilis, Bacillus megaterium, Staph aureus and Streptococcus pyogenes), Gram-negative (Escherichia coli, Proteus vulgaris, Proteus mirabilis and Enterobacter aerogenes) bacterial and fungal (Aspergillus niger, Candida albicans, Fusarium oxysporum, Fusarium solani) strains by disc diffusion method and the minimum inhibitory concentration (MIC) in which it has been recorded in microgram per milliliter in comparison to the reference drugs, ciprofloxacin (antibacterial) and nystatin (antifungal). Further, the cytotoxicity (IC 50 value) has also been assessed on human cervical (HeLa), Supt1 cancer cell lines by using MTT assay. Conclusions: The following screened compounds (4d), (4f), (4g), (4k), (4l), (4o) and (4u) were found to be the best active against all the tested bacterial and fungal strains among all the demonstrated compounds of biological study. The MIC determination was also carried out against bacteria and fungi, the compounds (4f) and (4u) are found to be exhibited excellent potent against bacteria and fungi respectively. The compounds (4f) and (4u) were shown non-toxic in nature after screened for cytotoxicity against the cancer cell lines of human cervical (HeLa) and Supt1. Additionally, structure and antibacterial activity relationship were also further supported by in silico molecular docking studies of the active compounds against DNA topoisomerase.
Arkivoc, 2008
A series of 1-[2-(1H-benzimidazol-1-yl)acetyl]-2,6-diarylpiperidin-4-ones (21-30) has been synthesized under mild conditions in good yield. Structural assignments and conformational analysis of the compounds were established through one-(1 H and 13 C) and two-dimensional (NOESY and HSQC) NMR studies. A significant upfield shift of proton and carbon at position 'g' of the benzimidazole moiety and phenyl ortho protons of the piperidone system is considered to originate from the anisotropic influence of the suitably positioned π bond containing amide carbonyl group. Dynamic NMR studies proved the existence of restricted rotation and coplanarity of the amide N-C=O carbonyl group and was further confirmed by X-ray crystallographic study of 20. Besides, the rotomers resulting from restricted rotation undergo fastest interconversion on NMR time scale at ambient temperature while at low temperatures, slow exchange occurs leading to a set of signals corresponding to cis and trans rotomers with perfectly equal intensity. The possible factors for the non-broadening of the benzimidazole signals even at very low temperature is explained through dynamic NMR studies. Mass spectral studies indicate a common mode of cleavage among the symmetrically and unsymmetrically substituted analogues. Measurement of antimicrobial activity showed that compounds 23, 24 and 25 exhibited a better activity profile towards the tested microbial strains.
CHEMICAL & PHARMACEUTICAL BULLETIN, 2009
A new series of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2-(aryl)-3,3a,5,6-tetrahydro-2Hpyrazolo[3,4-d][1,3]thiazol-5-yl]phenyl]methanes 6a-r was synthesized by the reaction of arylidine derivative of methylene-bis-thiazolidinones 5a-c with aryl/alkyl hydrazines. Chemical structures of all the new compounds were established by IR, 1 H-NMR, 13 C-NMR, MS and elemental data. The compounds 6a-r were evaluated for their nematicidal activity against Ditylenchus myceliophagus and Caenorhabdites elegans by aqueous in vitro screening technique. Amongst them compounds containing N-benzylpyrazole moiety (6d, 6j, 6p), and Nmethylpyrazole moiety (6f, 6l, 6r) showed significant nematicidal activity against both the test nematodes with LD 50 160-210 ppm, almost equal to the oxamyl standard. Further, these compounds 6a-r were screened for their antibacterial (MZI, MIC and MBC) activity against three representative Gram-positive bacteria viz. Bacillus subtilis (MTCC 441), Bacillus sphaericus (MTCC 11), Staphylococcus aureus (MTCC 96) and three Gramnegative bacteria viz. Pseudomonas aeruginosa (MTCC 741), Klebsiella aerogenes (MTCC 39), Chromobacterium violaceum (MTCC 2656) and also screened for their antifungal (MZI, MIC and MFC) activity against four fungal organisms viz. Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185) and Trichophyton mentagrophytes (IFO 40996). Most of these new compounds showed appreciable activity against test bacteria and fungi, and emerged as potential molecules for further development.
Archiv der Pharmazie, 2002
In the present study, a new series of Schiff's bases derived from (4-Benzoxazol-2-yl-phenyl)isopropylidine-amine (2a-j) have been synthesized by reacting the amino group of the 4-Benzoxazol-2-yl-phenylamine (1) with different aromatic/ hetero aromatic aldehydes in presence of glacial acetic acid. The starting material 4-Benzoxazol-2-yl-phenylamine was synthesized by condensation of o-aminophenol and p-amino benzoic acid, catalyzed by polyphosphoric acid. The structural assessment of the compounds (2a-j) was made on the basis of spectral data. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria and fungi viz., Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, Aspergillus niger, Rhizopus oryzae, Candida albicans and Penicillium chrysogenum were compared with standard agents such as Ciprofloxacin (10µg/ml) and Fluconazole (10µg/ml) using agar diffusion technique. Compounds 2b, 2c, and 2d exhibit highest antibacterial activity and compounds 2b, 2c, 2d and 2h showed good antifungal activity.