Syntheses and biological activity of 2-(4′-diethylsulfonamide phenyl)-4-substituted aminomethyl-1,3,4-oxadiazolin-5-thiones

4-(Chlorosulfonyl) benzoic acid was condensed with diethyl amine to afford 4(diethylsulfamoyl) benzoic acid I which was esterified to obtain methyl ester 2. The condensation of compound 2 with hydrazine hydrate gave hydrazino derivative 3. This intermediate undergoes cyclization with carbon disulphide and potassium hydroxide to yield substituted 1,3,4-oxadiazolin-5-thione 4. Aminomethylation of 4 using different amines furnished 4-substituted aminomethyl-2-(4'-diethylsulphonamide phenyl)-1,3,4-oxadiazolin-5-thiones 5a-e. The structure of the newly synthesized compounds have been established by analytical and spectral data. These compounds have also been screened for their biological activity.