Synthesis and antibacterial activity of a new series of 3-[3-(substituted phenyl)-1-phenyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives.

A series of 3-[3-(substituted phenyl)-1-phenyl-1H-pyrazol-5-yl]-2H-chromen-2-one (4a-k) were synthesized by reaction of 3-[2,3-dibromo-3-(substituted phenyl)propanoyl]-2H-chromen-2-one (3 a-k) with phenyl hydrazine in presence of triethylamine in absolute ethanol, characterized by spectral data and screened for their in vitro antibacterial activity against gram-positive and gram-negative bacteria. Among the series, compounds 4d, 4h and 4i displayed an encouraging antibacterial activity profile as compared to reference standard drug ciprofloxacin against tested bacterial strains.

Synthesis and antibacterial activity of a novel series of 2,3-diaryl-substituted-imidazo(2,1-b)-benzothiazole derivatives.

Benzothiazole and imidazole compounds are extensively studied heterocyclics due to their wide spectrum of bioactivities. Among them, the imidazo(2,1-b)-benzothiazole derivatives are pharmacologically important because of their immunostimulant, anti-inflammatory, antifungal, antimicrobial, antitumor, and other activities. In the present research work, a novel series of 2,3-diaryl-substituted imidazo(2,1-b)-benzothiazoles 13a-o have been synthesized by reaction of substituted 2-aminobenzothiazoles 1-8 and an appropriately substituted alpha-bromo-1-(4''-substituted)-phenyl-2-(4'-substituted)-phenyl-1-ethanones 9-12 in the presence of anhydrous acetonitrile. They were characterized by physicochemical, elemental, and spectral (IR, (1)H-NMR, and Mass) data. All the synthesized compounds were screened for their in-vitro antibacterial activity against Gram-positive, Gram-negative bacteria. The investigation of antibacterial screening data revealed that most of the compounds tested have demonstrated congruent activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa as compared with the standard ampicillin. Among the series, compounds 13d, 13h, and 13m exhibited excellent an antibacterial activity profile as compared with the standard. In summary, preliminary results indicate that some of the newly synthesized title compounds exhibited promising antibacterial activities and they warrant more consideration as prospective antimicrobials.

Synthesis and antimicrobial activity of 7-(2-substituted phenylthiazolidinyl)-benzopyran-2-one derivatives.

A series of 7-(2-substituted phenylthiazolidinyl)-benzopyran-2-one derivatives have been synthesized by reaction of 7-amino-4-methyl-benzopyran-2-one (1) with an appropriate substituted aldehydes to obtain various Schiff bases (3a-k) which on treatment with thioglycolic acid afforded the title compounds (4a-k). Purity of the compounds has been confirmed by TLC. Structure of these compounds were established on the bases IR, 1H NMR, 13C NMR and Mass spectral data. Schiff bases and title compounds were evaluated for antibacterial and antifungal activities against various bacterial and fungal strains. The results showed that compounds 3d, 3f, 4d, 4f and 4i (100 microg/ml) exhibited good antibacterial and antifungal activity as that of standard antibiotics Ciprofloxacin and Griseofulvin.

Synthesis and antimycobacterial activity of a novel series of isonicotinylhydrazide derivatives.

A novel series of 14 new isonicotinyl hydrazide derivatives 2a-g, 3a-g containing a 4-thiazolidinone / 2-azetidinone nucleus were synthesized by reacting N'-substituted arylidene / heteroarylidene isonicotinyl hydrazide 1a-g with thioglycollic acid in the presence of dry benzene and with chloroacetyl chloride in the presence of triethylamine, respectively. Structures of all newly synthesized compounds were characterized on the basis of elemental analyses and spectral data (IR and (1)H-NMR). All the title compounds were tested for their in-vitro antimycobacterial activity against Mycobacterium tuberculosis H(37)Rv using Alamar-Blue susceptibility test, and the activity is expressed as the minimum inhibitory concentration (MIC) in microg/mL. Among the series, compounds 2b, 2g, 3b, and 3g displayed an encouraging antimycobacterial activity profile as compared to that of the reference drugs isoniazid / rifampicin.

Synthesis and antibacterial activity of a new series of 3-[3-(substituted phenyl)-1-isonicotinoyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives.

A novel series of 3-[3-(substituted phenyl)-1-isonicotinoyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives 4a-k have been synthesized by the reaction of 3-[2,3-dibromo-3-(substituted phenyl) propanoyl]-2H-chromen-2-one 3a-k and isonicotinic acid hydrazide in the presence of triethylamine in absolute ethanol, characterized by spectral data and screened for their in-vitro antibacterial activity against Gram-positive and Gram-negative bacteria. Among the series, compounds 4e, 4i, and 4k displayed an encouraging antibacterial activity profile as compared to the reference drug ampicillin against tested bacterial strains.

Synthesis and pharmacological evaluation of a novel series of 5-(substituted)aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazolines as novel anti-inflammatory and analgesic agents.

A novel series of 5-(substituted)aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazolines (3a-l) were synthesized by reacting various substituted 3-aryl-1-(3-coumarinyl)propan-1-ones (2a-l) with phenylhydrazine in the presence of hot pyridine. Structures of all new synthesized compounds were characterized on the basis of elemental analysis and spectral data (IR, (1)H NMR and (13)C NMR). The title compounds were screened for in vivo anti-inflammatory and analgesic activities at a dose of 200 mg/kg b.w. Among the 12 prepared compounds, Compounds 3d, e, i and j exhibited significant anti-inflammatory activity in model of acute inflammation such as carrageenan-induced rat edema paw while compounds 3d and e showed considerable activity in model of chronic inflammation such as adjuvant-induced arthritis and were compared with diclofenac (13.5 mg/kg b.w.) as a standard drug. These compounds were also found to have significant analgesic activity in the acetic acid induced writhing model and antipyretic activity in yeast-induced pyrexia model along with minimum ulcerogenic index.

Synthesis and evaluation of antiinflammatory and analgesic activities of a novel series of coumarin Mannich bases.

A novel series of coumarinyl Mannich bases (3a-1) have been synthesized by reacting 3-acetyl coumarin (1) with various substituted secondary amines (2a-1) in presence of paraformaldehyde. The structures of the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and HRMS (high resolution mass spectral) data. Title compounds were screened for in vivo acute anti-inflammatory activity using the carrageenan-induced rat paw edema assay model. Among the compounds tested, 3-[3-(diethylamino)propanoyl]-2H-chromen-2-one (3a)and 3-[3-(piperidine-1-yl) propanoyl]-2H-chromen-2-one (3c) showed 63.1 and 66.7% inhibition, respectively, as compared to the standard drug diclofenac (CAS 15307-86-5, 68.8%). These potent compounds showed encouraging analgesic andantipyretic activities.

Synthesis of novel substituted 7-(benzylideneamino)-4-methyl-2H-chromen-2-one derivatives as anti-inflammatory and analgesic agents.

A series of novel Schiff' base-containing a 7-amino-4-methylcoumarin moiety have been synthesized III a-l, characterized by spectroscopic data and studied for their anti-inflammatory and analgesic activity. The results of the anti-inflammatory and analgesic activity evaluation of 7-(substituted benzylideneamino)-4-methyl-2H-chromen-2-one derivatives III a-l proved to be comparable or more potent with respect to the reference drugs. In particular, compounds 7-(4-chlorobenzylideneamino)-4-methyl-2H-chromen-2-one III f, 7-(2,4-dichlorobenzylideneamino)-4-methyl-2H-chromen-2-one III g and 7-(4-bromobenzylideneamino)-4-methyl-2H-chromen-2-one III h exhibited potent anti-inflammatory and analgesic activity.

Synthesis and evaluation of anti-inflammatory and analgesic activities of a novel series of substituted-N-(4-methyl-2-oxo-2H-chromen-7-yl) benzamides.

A novel series of coumarinyl amides (IVa-l) have been synthesized by reacting 7-amino-4-methylcoumarin (III) with various substituted aromatic acid chlorides. IR, 1H NMR, 13C NMR and HRMS spectral data characterized the structure of the synthesized compounds. The title compounds were screened for in vivo acute anti-inflammatory activity using the carrageenan-induced rat paw edema assay model. Among the compounds tested, 2-chloro-N-(4-methyl-2-oxo-2H-chromen-7-yl)benzamide (IVb) and 4-chloro-N-(4-methyl-2-oxo-2H-chromen-7-yl)benzamide (IVc) showed 60.5 and 62.3% edema protection, respectively, as compared to the standard drug diclofenac (CAS 15307-86-5) (63.5%) after third hour. Compounds N-(4-methyl-2-oxo-2H-chromen-7-yl)-4-nitrobenzamide (IVf) and N-(4-methyl-2-oxo-2H-chromen-7-yl)cinnamamide (IVg) showed moderate activity. The new compounds have been also tested for in vivo analgesic activity. Quantitative structure-activity relationship studies indicated that the chloro substitution at the aromatic ring enhanced the anti-inflammatory activity (IVb and IVc). These compounds were also found to provide significant protection in acetic acid induced writhing animal model, showing remarkable analgesic activity. Compounds IVb and IVc showed 55.1% and 56.3% protection, respectively, as compared to acetylsalicylic acid (CAS 50-78-2) (57.7%).