MICROWAVE ASSISTED SOLVENT FREE SYNTHESIS AND EVALUATION OF ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES OF SOME NOVEL 3, 4-BIS (SUBSTITUTED PHENYL)-7-(6-METHYL PYRIDIN-2-YL)-3, 3A, 3B, 4-TETRAHYDRO7H-PYRROLO [2, 3-C : 5,4-C']DIISOXAZOLE

Abstract

Novel heterocyclic compounds were synthesized, characterized and screened for antimicrobial activity and antioxidant activity. This series of novel bis-isoxazole derivatives were synthesized via reaction of bis chalcone of succinimide treated with hydroxyl amine hydrochloride in presence of neutral alumina by microwave assisted solvent free method in good yield. It was observed that microwave assisted method produced a greater yield of products in shorter reaction times. The structures of synthesized compounds were characterized by their spectral analyses (elemental analysis, FTIR, 1H NMR) and the purity of synthesized compounds were confirmed by TLC. All the synthesized compounds were evaluated for antimicrobial activity against gram positive bacteria Staphylococcus aureus (NCIM 2079) and gram negative bacteria Escherichia coli (NCIM 2109) using DMSO solvent and antifungal activity against fungal strain Aspergillus Niger (NCIM 545). Most of the synthesized compounds exhibited a moderate grade of anti-microbial activity. The study concluded that the compound 4c exhibited potent anti-bacterial activity when compared to Chloramphenicol as standard drug while compound 4b, 4c, 5b, 5c, 5e exhibited significant anti-fungal activity when compared to Amphotericin B as standard drug. All the synthesized compounds were screened for their antioxidant activities. Among them, compounds 4a, 4e, 5a, 5b, 5c and 5e showed moderate to good antioxidant activity when compared to ascorbic acid as standard drug.