In the present study, various N-alkyl substituted derivatives of benzene-sulfonamide were synthesized. In the first step, benzene sulfonyl chloride was treated with 2-amino-2-methyl-1-propanol afforded N-(2-hydroxy-1,1-dimethylethyl)-benzenesulfonamide and in next step this parent compound was reacted with alphatic halides to produced different N-alkylation substituted derivatives. Oxadiazole are very important compounds that are strongly biologically active. In this study the parent compound 5-benzyl-1,3,4 oxadiazole-2-thiole was synthesized by hydrazinolysis of ethyl phenylacetate followed by reaction with carbon disulfide. Further the parent compound oxadiazole was treated with different aliphatic alkyl groups to produce eight different S-substituted derivatives of oxadiazole. All these synthesized derivatives of sulfonamides and oxadiazoles were characterized by melting point, IR, EI-MS, 1H-NMR and X-ray crystallographic techniques. These compounds were screened.to evaluate their biological activity and only sulfonamides showed inhibition potentials against butyrylcholinesterase.