Efficient electrochemical synthesis, antimicrobial and antiinflammatory activity of 2-amino-5-substituted-1,3,4-oxadiazole derivatives

S Kumar,Dp Srivastava

doi:10.4103/0250-474x.73917

Abstract

An efficient electrochemical method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (4a-k) at platinum anode through the electrooxidation of semicarbazone (3a-k) at controlled potential electrolysis has been reported in the present study. The electrolysis was carried out in the acetic acid solvent and lithium perchlorate was used as supporting electrolyte. The products were characterized by IR,1H-NMR,13C-NMR, mass spectra and elemental analysis. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria viz., Klebsilla penumoniae, Escherichia coli, Bassilus subtilis and Streptococcus aureus and antifungal activity against Aspergillus niger and Crysosporium pannical and results have been compared with the standard antibacterial streptomycin and antifungal griseofulvin. Compounds exhibits significant antibacterial activity and antifungal activity. Compounds 4a and g exhibited equal while 4c, d, i and j slightly less antibacterial activity than standard streptomycin. Compounds 4a and g exhibited equal while 4b, c, d, f and i displayed slightly less antifungal activity than standard griseofulvins.

Highlights

An efficient electrochemical method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (4a-k) at platinum anode through the electrooxidation of semicarbazone (3a-k) at controlled potential electrolysis has been reported in the present study
Organic synthesis involving multi-component reactions under reagent-free conditions is a basic protocol because multistep conventional synthesis produces considerable amounts of environmentally unfavorable wastes, mainly due to a series of complex isolation procedures often involving expensive, toxic and hazardous solvents and reagents after each step
The purity of the synthesized compounds were ascertained by TLC on precoated silica gel plates in various solvent systems using iodine vapors and UV light as detecting agent

Summary

Introduction

An efficient electrochemical method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (4a-k) at platinum anode through the electrooxidation of semicarbazone (3a-k) at controlled potential electrolysis has been reported in the present study. H); 13C NMR (DMSO-d , δ ppm): 158.9 (C), 147.7 6 (C), 140.6 (C), 132.9 (CH), 131.9 (CH), 125.1 (C), 115.4 (C), 106.4 (CH); MS m/z: 240 (M+), 241 (M+ + 1, 100%) for C8H6N3OBr. 2-amino-5-(p-bromophenyl)-1,3,4-oxadiazole (4c): Brownish crystals; mp: 69-70o; IR (KBr, cm-1): 3360 (NH), 3045 (C-H aromatic), 1615 (C=N-N=C), 1475 (C=C aromatic), 1275, 1075 (C-O-C), 985, 890, 755, 597 (substituted benzene); 1H NMR (DMSO-d , δ ppm): 7.75 (s, 2H, NH ), 7.71 (d, 2H, aromatic H), 2

Results

Conclusion