Synthesis and antibacterial activity of some 5-(2,4-dichlorophenyl)-1,3,4- oxadiazol-2-yl substituted benzothioates

A series of 5-(2, 4-dichlorophenyl)-1, 3, 4-oxadiazol-2-yl substituted benzothioateswas synthesized and studied for their antibacterial activity. These compounds were prepared from 2, 4-dichloro benzoic acid hydrazide. 2, 4- dichloro benzoic acid hydrazide 1 on refluxing with carbon disulfide and methanolic potassium hydroxide and then on subsequent acidification with hydrochloric acid furnished 5-(2, 4-dichlorophenyl)-1, 3, 4-oxadiazole-2-thiones 2. Aroyl chlorides reacted with 2 in Schotten-Baumann reaction conditions yielded the title compounds 3. These compounds were characterized by modern spectroscopic techniques. All the compounds were evaluated for their in vitro antibacterial activity against two Gram negative strains (Escherichia coli and Pseudomonas aeruginosa) and two Gram positive strains (Bacillus subtilis and Staphylococcus aureus) and their minimum inhibitory concentration (MIC) were determined.