title: Thermal solvent-free synthesis of novel pyrazolyl chalcones and pyrazolines as potential antimicrobial agents.
abstract: A novel approach was adopted for the synthesis of series of new pyrazolyl chalcones (3a-c) by the reaction of 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde (1) with different 5-acetylbarbituric acid derivatives (2a-c) under thermal solvent-free condition. The chalcones were then converted to the corresponding pyrazolines (4a-c) under the same condition in excellent yields. All the synthesized compounds were characterized using elemental analysis and spectral data (IR, (1)H NMR, and mass spectrometry). The synthesized compounds were tested for their antimicrobial activity by disk diffusion assay with slight modifications against Gram-positive, Gram-negative strains of bacteria as well as fungal strains. The investigation of antimicrobial screening revealed that compounds (3a-4c) showed good antibacterial and antifungal activities, respectively. Among the screened compounds, 3b showed more potent inhibitory activity (MIC=12.5 μg/ml) nearly to that of standard antibiotics ciprofloxacin, griseofulvin and fluconazole.
authors.affiliation: Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, India. siddiqui_zeba@yahoo.co.in
authors.forename: Zeba N
authors.initials: ZN
authors.lastname: Siddiqui
authors.forename: T N Mohammed
authors.initials: TN
authors.lastname: Musthafa
authors.forename: Anis
authors.initials: A
authors.lastname: Ahmad
authors.forename: Asad U
authors.initials: AU
authors.lastname: Khan
mesh_terms: D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D047188:Chalcones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D012997:Solvents / Q000737:chemistry; D013696:Temperature
chemical_list: D000890:Anti-Infective Agents; D047188:Chalcones; D011720:Pyrazoles; D012997:Solvents