Synthesis of some 5-chloro-6-substituted-3-methyl-2-oxo-3h-benzoxazole derivatives studies on their antibacterial and antifungal activities

In this study, nine new compounds containing urea and thiourea groups at position 6 of the 5-chloro-3-methyl-2-oxo-3H-benzoxazole ring were synthesized and their structures were confirmed by 1H-NMR, Mass and elemental analysis. After that, their antimicrobial activities were evaluated various Gram-positive and Gram-negative strains of bacteria, fungi and M. Tuberculosis H37Rv.The urea derivatives which were obtained by the reaction of 6-amino-5-chloro-3-methyl-2-oxo-3H-benzoxazole with the appropriate isocyanates were generally found more active against E. coli ATCC 35218, E. faecalis and fungi, but the thiourea derivatives which were obtained by the reaction of 6-amino-5-chloro-3-methyl-2-oxo-3H-benzoxazole with the appropriate isothiocyanates were generally found more active against E. coli ATCC 35218 and fungi.Among the synthesized compounds; 1, 2, 4, 6 and 9 showed the best inhibitory activity against E. coli ATCC 35218 with 32 µg/ml MIC value. Moreover, compounds 1 and 3 were the most active against E. faecalis with 16 µg/ml MIC value.