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.