Fungitoxicity of newly synthesized organophosphorus derivatives containing schiff bases of 2-hydrazino-1, 3, 4-thiadiazoles

Twelve novel organophosphorus derivatives have been prepared by the reaction of O, O-diethylchlorophosphate with Schiff bases derived from 2-hydrazino-5- (phenyl/substituted phenyl)-1, 3, 4-thiadiazoles. The derivatives have been characterized on the basis of analysis and spectral (IR, ¹H 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. Organophosphorus derivatives with Schiff bases derived from 2-hydrazino-5-phenyl-(4-chlorophenyl/2-chlorophenyl)-1, 3, 4-thiadiazoles and 4-hydroxy acetophenone proved to be more active than some prevalent commercial synthetic fungicides.