Studies on biologically active heterocycles. Part I. Synthesis and antifungal activity of some new aroyl hydrazones and 2,5‐disubstituted‐1,3,4‐oxadiazoles

A series of new 1‐(2,4‐dichlorobenzoyl) hydrazones and 2‐aryl/aralkyl‐5‐(2,4‐dichlorophenyl)‐1,3,4‐oxadiazoles have been synthesized from 2,4‐dichlorobenzoylhydrazine and different aldehydes. Subsequent ring closure of the substituted aroyl hydrazones yielded the 1,3,4‐oxadiazoles. All the compounds were characterized by their sharp melting point, microanalysis, ir, 1H nmr and mass spectra and screened for their fungitoxic properties against Alternaria tenuis and Curvularia verruciformis. A few of the compounds showed good activity.