Synthesis, characterization and antimicrobial activity of some new isoxazole derivatives

A series of isoxazole derivatives, 3-aryl-5-[5-(4-nitrophenyl)-2-furyl]-2,3-dihydroisoxazoles (5a-j) were synthesized by cyclocondensation reaction between 1-aryl-3-[5-(4-nitrophenyl)-2-furyl]prop-2-en-1-ones (4a-j) and hydroxylamine hydrochloride in presence of sodium acetate in glacial acetic acid at reflux temperature. Formerly, compounds (4a-j) were synthesized by the condensation of 5-(4-nitrophenyl) furan-2-carbaldehyde (3) with various aromatic ketones by using alkali as catalyst. The structures of the synthesized various isoxazole have been characterized by using elemental analysis, Infrared,1H-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity towards Aspergillus niger at a concentration of 40 µg/ml. It was exposed that the compounds 5a, 5c, 5e, 5f, and 5i showed inspiring antibacterial and antifungal activity compared to the used reference standard.