Microwave-assisted synthesis of some new tetrazolo[1,5-a]quinoline-based benzimidazoles catalyzed by p-TsOH and investigation of their antimicrobial activity

Abstract

Keeping the objective to build up a new structural class of potent antimicrobials, a series of some new 4-Benzimidazol-2-yl tetrazolo[1,5-a]quinoline derivatives has been synthesized by reaction of tetrazolo[1,5-a]quinoline-4-carbaldehyde and o-phenylenediamine in the presence of an organocatalyst p-TsOH under the influence of microwave irradiation. The identity of all the compounds has been established by 1 H NMR, 13 C NMR, FTIR, and elemental analysis. The synthesized compounds were subjected to in vitro antimicrobial screening against a representative panel of pathogenic strains including three Gram-positive bacteria (Bacillus subtilis, Clostridium tetani, and Streptococcus pneumoniae) and three Gramnegative bacteria (Escherichia coli, Salmonella typhi, and Vibrio cholerae) as well as two fungal organisms (Aspergillus fumigatus and Candida albicans) by employing broth microdilution method. Of the compounds studied, compound 5e demonstrated significant activity against a Grampositive bacteria Bacillus subtilis.

Synthesis, characterization and biological activity of some new carbostyril bearing 1H-pyrazole moiety

“…As part of our ongoing research in discovery of new active antimicrobial compounds (Makawana et al, 2011;Ladani et al, 2009aLadani et al, , b, 2010Mungra et al, 2009Mungra et al, , 2011Nirmal et al, 2009Nirmal et al, , 2010Shah et al, 2009a, b;Shah and Patel, 2011;Thakor et al, 2008;Patel, 2009a, b, 2011), in this article, we try to study the influence of carbostyril moiety and pyrazole scaffold combination on the antimicrobial effect. So we report herein the synthesis of some new derivatives of 4-pyrazolyl-N-arylquinoline-2,5-dione 4a-p through MCR approach.…”

Synthesis, characterization, and antimicrobial evaluation of carbostyril derivatives of 1H-pyrazole

“…In view of these particulars and by taking into account a modification on the quinolone nucleus can bring significant changes in pharmacological activities and can afford new classes of therapeutically active compounds for biomedical screening containing therapeutically active moieties pyrazole and quinolin-2-one and as part of our current studies in developing new antimicrobial agents containing quinoline (Ladani et al, 2009a(Ladani et al, ,b, 2010Mungra et al, 2009Mungra et al, , 2010Nirmal et al, 2009;Shah et al, 2009;Thakor et al, 2008) and 1H-pyrazole-4-carbaldehyde Patel, 2009a, 2011;Shah et al, 2009) derivatives, we report herein the synthesis of some new derivatives of 4-pyrazolyl-N-arylquinoline-2,5-dione (4a-l) via multicomponent reaction approach. The constitution of all the products was characterized using elemental analysis, FT-IR, 1 H NMR, 13 C NMR and mass spectrometry.…”

Synthesis of heterocyclic monoazo dyes derived from 1H-benzo[g]pyrazolo[3,4-b]quinoline-3-ylamine: their antimicrobial activity and their dyeing performance on various fibers

“…Hence, in continuation of our research work on developing quinoline and benzoquinoline-containing heterocyclic azo compounds, because of their significant biological and dyeing applications, it seemed expedient to synthesize a series of heterocyclic monoazo compounds as possible antimicrobial and dyeing agents. Quinoline and benzoquinoline rings combined with five or six member rings in a linear arrangement are known to have good pharmacological activity and are also used as intermediates in the dyestuffs industry [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Therefore, it was thought of interest to synthesize a series of a heterocyclic monoazo dyes derived from 1H-benzo [g]pyrazolo [3,4-b]quinoline-3-ylamine which not only have good dyeing properties but also have pharmacological (antibacterial and antifungal) activity.…”