Synthesis and Evaluation of Some New 5-Substituted-1,3,4- Oxadiazol-2Yl-4-(MORPHOLIN-4YL SULFONYL)Benzyl Sulfides As Antibacterial Agent
Purpose: To synthesise a new series of 5-substituted-1,3,4-Oxadiazol-2yl-4-(morpholin-4yl sulfonyl)benzyl sulfide and evaluate their antibacterial activity.
Methods: Different organic acids were converted consecutively into corresponding esters, hydrazides and 5-substituted-1,3,4-Oxadiazol-2-thiols (4a-e). The targets, 6a-e were synthesized by stirring 4a-e with 4-(4-(bromomethyl)phenylsulfonyl) morpholine (5) in the presence of N,N-dimethylformamide (DMF) and sodium hydride (NaH). All the structures were elucidated by modern spectroscopic techniques and screened against bacteria using standard procedure and ciprofloxacin drug as positive control.
Results: The yield of the synthesized compounds (4a-e and 6a-e) were moderate (65 - 90 %). Compounds 6a-e had antibacterial activity against Pseudomonas aeruginosa, Bacillis subtilis and Staphylococcus aureus while some had activity against the other bacteria used. One of the compounds, 6b, exhibited significant activity against all the bacterial strains, i.e., S. typhi (-), E. coli (-), K. pneumoniae (-), P. aeruginosa (-), B. subtilis (+) and S. aureus (+) with MIC (μM) values of 11.01 ± 0.31, 15.37 ± 3.33, 16.11 ± 1.14, 9.70 ± 1.96, 10.01 ± 2.70 and 9.15 ± 0.29, respectively. However, none of the compounds had any inhibitory activity against any bacteria as high as that of ciprofloxacin.
Conclusion: Five new compounds with antibacterial activities have been synthesized. Their potential as therapeutic agents is, however, yet to be evaluated.