SYNTHESIS AND MICROBIOLOGICAL ACTIVITY OF SOME NOVEL N-(2-HYDROXYL-5-SUBSTITUTEDPHENYL)BENZACETAMIDES, PHENOXYACETAMIDES AND THIOPHENOXYACETAMIDES AS THE POSSIBLE METABOLITES OF ANTIMICROBIAL ACTIVE BENZOXAZOLES

Synthesis of some novel N-(2-hydroxyl-5-substitutedphenyl)benzacetamid es, phenoxyacetamides and thiophenoxyacetamides (5a-k) were described in order to determine their in vitro antimicrobial activity against 3 Gram-positive, 3 Gram-negative bacteria and the fungus Candida albican s comparing with several control drugs. The derivative 5e was found ac tive at a MIC value of 25 mu g/ml against the whole tested Gram-positi ve bacteria strains and the Gram-negative microorganism Klebsiella pne umoniae. Moreover, the synthesized compounds 5a-k exhibited significan t antibacterial activity against the enterobacter Pseudomonas auregino sae when compared to the control drugs. For the antifungal activity ag ainst C. albicans, the compound 5k was found more active than the othe r synthesized derivatives. On the other hand, the antimicrobial activi ty of some of these acetamide derivatives (5c, 5d, 5e, 5j and 5k) whic h are the possible metabolites of benzoxazoles, were also compared wit h their cyclic analogues 6-10. However, most of the MIC values of the benzoxazole derivatives provided better activity than the compared ace tamides, while some others of the acetamide derivatives possessed eith er one fold improved (5d, 5e and 5j) or the same potency (5c, 5d, 5e, 5j and 5k) against the tested microorganisms.