Synthesis, Spectral Characterization and Biological Activity of S-Substituted Derivatives of 5-(4-Nitrophenyl)-1,3,4-oxadiazole-2-thiol

Asian Journal of Pharmaceutical and Health Sciences,2012,2,3,370-376.
Published:August 2012
Type:Research Article
Author(s) affiliations:

Aziz-ur-Rehman1*, Khadija Nafeesa1, Muhammad Athar Abbasi1, Hira Khalid1, Khalid Mohammed Khan2, Muhammad Ashraf3, Irshad Ahmad4, Syeda Abida Ejaz4

1Department of Chemistry, Government College University, Lahore-54000, Pakistan.

2HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.

3Department of Biochemistry and Biotechnology; 4Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur-63100, Pakistan.


A series of S-substituted derivatives of 5-(4-nitrophenyl)-1,3,4- oxadiazole-2-thiol (6a-l) were synthesized in various steps. Organic acid 4-nitrobenzoic acid (1) was successfully converted into ester and consequently into its hydrazide in the presence of hydrazine hydrate and methanol as a solvent. Further, 4- nitrobenzoic acid hydrazide (3) yielded 5-(4-nitrophenyl)-1,3,4- oxadiazole-2-thiol, on treatment with carbon disulfide in the presence of base (KOH) and ethanol. Finally the target compounds (6a-l) were obtained by stirring 5-(4-nitrophenyl)- 1,3,4-oxadiazole-2-thiol with different electrophiles (5a-l) in the presence of sodium hydride (NaH) and dimethyl formamide (DMF). All these derivatives along with their parent compounds were characterized by IR, EI-MS and 1H-NMR spectra. These compounds were assayed for their antioxidant activities and other biological activities via screening them against acetylcholinesterase, butyrylcholinesterase and lipoxygenase enzymes, however, these showed prominent activity against acetylcholinesterase and butyrylcholinesterase enzymes.

Outline for the synthesis of S-substituted derivatives