International Journal of Chemical Studies
Vol. 7, Special Issue 6 (2019)
Synthesis and fungitoxicity evaluation of schiff bases of 4-amino-3-mercapto-5-phenyl-1,2,4-triazole
Author(s): Arnab Roy Chowdhury and RL Gupta
Abstract: Schiff base is a functional group or a chemical compound containing, carbon-nitrogen double bond. It is also called imine or azomethine. Schiff bases of various heterocyclic moieties find their applications as drugs and have also been classified under pesticides. Schiff bases of 4-amino-1,2,4-triazoles have already been reported for their antifungal, antibacterial and PGR activities. Some derivatives of 4-amino -1,2,4-triazoles have recently been reported to exhibit potential fungicidal activity.
In an attempt to discover potential fungicides, a series of twenty Schiff bases (SB1 to SB20), 4-arylidenamino-3-mercapto-5-phenyl-4H-1,2,4-triazoles having different substitution in the aryl ring attached to imino group were synthesized following a five step synthesis scheme starting with benzoic acid. Three of the five steps of this synthesis were accomplished by using microwaves. The microwave synthesis has been found much faster and efficient than conventional method. The yields of the synthesized Schiff bases were obtained in range of 52-92%. The structures of the Schiff bases were characterized by elemental analysis, FT-IR and NMR spectroscopy.
The Schiff bases were evaluated for fungitoxicity against three phytopathogenic fungi viz. Rhizoctonia solani, Fusarium oxysporum and Bipolaris sorokiniana. Among all the compounds in this series, SB-9 having methyl group in meta position of aryl ring (ED50 = 17.34 ppm), SB-4 having chlorine in the para position of aryl ring (ED50=95.55 ppm) and SB-3 having chlorine in the meta position of aryl ring (ED50=181.3 ppm) exhibited the higher activity against R. solani, F. oxysporum and B. sorokiniana respectively. The most active compound in this series was SB-9 exhibited highest activity than the parent triazole against R. solani. Thus, the Schiff bases of traizoles may find its application as potential fungicides in the near future.
Pages: 03-08 | 201 Views 7 Downloads
How to cite this article:
Arnab Roy Chowdhury and RL Gupta. Synthesis and fungitoxicity evaluation of schiff bases of 4-amino-3-mercapto-5-phenyl-1,2,4-triazole. International Journal of Chemical Studies. 2019; 7(6): 03-08.