A series of 1‐(2,4‐dichlorobenzoyl)thiosemicarbazides, s‐triazoles and their methyl derivatives have been synthesised by condensation of 2,4‐dichlorobenzoyl hydrazine with aryl isothiocyanates. Subsequent ring closure of the substituted thiosemicarbazides yielded the s‐triazoles, and reaction with methyl iodide resulted methyl derivatives. All the compounds were subjected to in vitro testing against two gram‐positive and two gram‐negative bacteria. Antibacterial activity was found to be moderate to good in most of the compounds.

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.

Sixteen new 3‐arylaminomethyl‐5‐(2,4‐dichlorophenyl)‐1,3,4‐oxadiazole‐2‐thione and six 3‐alkyl aryl alkyl‐5‐(2,4‐dichlorophenyl)‐1,3,4‐oxadiazole‐2‐thiones were synthesised and characterised by their sharp melting points, elemental analysis, ir, 1H nmr and mass spectra. These substituted oxadiazolethiones were screened for their fungitoxic properties. Most of the compounds showed toxicity against two test organisms, Curvularia verruciformis and Alternaria tenuis. The degree of inhibition ranged from 38‐‐100% for a few compounds.