Fungitoxicity of Newly Synthesized Organophosphorus Derivatives Containing Schiff Bases of 5-Hydrazino-1,2,4-Triazoles

Ten novel organophosphorus derivatives have been prepared by the reaction of O,O-diethylchlorophosphate with Schiff bases derived from 3-(phenyl/2-chlorophenyl/2-methylphenyl/4-chlorophenyl/4-nitrophenyl)-4-amino5-hydrazino-1,2,4-triazoles with salicylaldehyde and 2-hydroxy acetophenone. The derivatives have been characterized on the basis of element analysis and spectral (IR, ¹H and ¹³C NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum and Curvularia pallescence have been evaluated. The screening results have been correlated with the structural features of the tested compounds. The greater potency has been observed in organophosphorus derivatives with Schiff bases derived from 2hydroxy acetophenone (IId) and with substituents Cl⁻attached to the aromatic ring compared to other substituents.