Synthesis and antimicrobial screening of pyrano[3,2-c]chromene derivatives of 1H-pyrazoles

Abstract

Abstract:© Versita Sp. z o.o. C NMR spectral data. All the synthesized compounds were screened against six bacterial pathogens, namely B. subtilis, C. tetani, S. pneumoniae, S. typhi, V. cholerae, E. coli and for antifungal activity against two fungal pathogens, A. fumigatus and C. albicans using the broth microdilution MIC method. Some of the compounds were found to be equipotent or more potent than commercial drugs against most of employed strains, as evident from the screening data.

Efficient tandem synthesis of a variety of pyran-annulated heterocycles, 3,4-disubstituted isoxazol-5(4H)-ones, and α,β-unsaturated nitriles catalyzed by potassium hydrogen phthalate in water

“…Several synthetic methods have been widely applied for synthesis of pyran-based heterocyclic compounds, using many homogeneous or heterogeneous organic, inorganic, and nanomaterial catalysts, for example hexamethylenetetramine (HMT) [40], heteropolyacid [41], diammonium hydrogen phosphate [42], DBU [43], piperidine [44][45][46][47], tetrabutylammonium bromide (TBAB) [48], ionic liquids [49], morpholine [50], 4-(dimethylamino)pyridine (DMAP) [51], urea [52], 3-hydroxypropanaminium acetate (HPAA) [53], N-propylpiperazine sodium n-propionate (SBPPSP) [54], silica gel [55], sulfonic acid-functionalized silica [ [60], meglumine [61], I 2 /K 2 CO 3 [62], cetyltrimethylammonium bromide (CTABr) [63], nano-sized MgO [64], nano-structured Na 2 CaP 2 O 7 [65], NaHCO 3 [66], Na 2 CO 3 [67], triazine-functionalized ordered mesoporous organosilica [68], potassium phosphate tribasic trihydrate [69], Mg/Al hydrotalcite [70], Amberlyst A21 [71], DABCO [72], CeO 2 /CaO nanocomposite oxide [73], triton B [74], tetrabutylammonium chloride (TBAC) [75], nano-eggshell powder [76], basic alumina [77], [bmim]OH [78,79], LiBr [80], glycine [81], silica nanoparticles [82], ionic liquid choline chlorid...…”

Synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives: assessment of their antimicrobial, antituberculosis and antioxidant activity

“…Thus, in view of the biological significance of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione, a modification on the 1-position of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione by 3-methyl-5-phenoxy-1-phenyl-1H-pyrazole was undertaken to check whether it brings significant changes in the bioactivities of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives. As a part of our current study in developing new antimicrobial agents via combination of two therapeutically active moieties [22][23][24][25], we report herein the C. B. Sangani et al preparation 1H-pyrazolo[1,2-b]phthalazine-5,10-dione 4a-p derivatives by an MCR approach.…”

“…In continuation of our interest on synthesizing biologically potent antimicrobials [22][23][24][25], we report herein a new series of 1H-Pyrazolo[1,2-b]phthalazine-5,10-dione derivatives (4a-p) via one-pot, three-component base-catalyzed cyclo condensation reaction of 3-methyl-5-aryloxy-1-aryl-1H-pyrazole-4-carbaldehyde (1a-d), malononitrile or ethyl cyanoacetate (2a-b) and 2,3-dihydro-1,4-phthalazinedione (3a-b) in ethanol containing eco friendly base NaOH in good to excellent yields (Scheme 1). The required starting material, 1-aryl-5-chloro-3-methyl-1H-pyrazole-4-carbaldehyde was prepared by using the procedure in the literature [26].…”

“…The required starting material, 1-aryl-5-chloro-3-methyl-1H-pyrazole-4-carbaldehyde was prepared by using the procedure in the literature [26]. 1-Aryl-5-chloro-3-methyl-1H-pyrazole-4-carbaldehyde undergoes a nucleophilic substitution reaction with respective phenol at refluxing temperature for 4 h in the presence of a basic catalyst (K2CO3) in DMF which resulted in the required 3-methyl-5-aryloxy-1-aryl-1H-pyrazole-4-carbaldehyde [22,23]. A possible mechanism for the reaction is outlined in Scheme 2.…”

Microwave-assisted synthesis of 3′-indolyl substituted 4H-chromenes catalyzed by DMAP and their antimicrobial activity

“…In the radiance of the aforementioned facts, and as a prolongation of our investigation on the synthesis of biologically active heterocyclic compounds Patel, 2009a, b, 2011a, b, c, d;Makawana et al, 2011a, b;Shah et al, 2001;Sangani 2011;Mungra et al, 2009Mungra et al, , 2011aLadani et al, 2009aLadani et al, , b, 2010Ladani et al, , 2011Nirmal et al, 2009Nirmal et al, , 2010Shah et al, 2009a, b), we were provoked to synthesize new indolebased 4H-chromene derivatives and evaluate them as antimicrobial agents.…”