Design and Synthesis of Some New 1,2,4- Triazolo[4,3-a]Quinoxaline Derivatives as Potential Antimicrobial Agents

As a part of an ongoing research program to achieve new chemical entities suitable for development as new class of antimicrobial agents, the present work describes the design and synthesis of a new series of substituted-1-methyl- 1,2,4-triazolo[4,3-a]quinoxalines, The newly synthesized compounds were screened for their in vitro antimicrobial activity. The results revealed that the compounds demonstrated significant activity against Gram negative bacteria. Compounds 3 and 11b exhibited twice the activity of ampicillin against Pseudomonas aeruginosa, while compounds 4, 5b, 7, 9a, 10d, 11a, 11c and 12 were equipotent to ampicillin. On the other hand, the tested compounds demonstrated mild antifungal activity. Compound 11d exhibited nearly one-half the activity of clotrimazole against Candida albicans. The structures of the synthesized compounds have been confirmed by elemental analyses, IR, MS, 1H-NMR and 13 C-NMR spectral data.