By the condensation of 3-(4'-pyridyl)-4-amino-5-mercapto-1,2,4-triazole with substituted benzoic acids in the presence of POCl3, nineteen novel 3-(4'-pyridyl)-6-aryl-s-triazolo[3,4-b]-1,3,4-thiadiazoles I (R = Me, MeO, NO2, Br, Cl, F, iodo) were obtained. Their structural proofs were based on elemental and spectral analyses. The above products whose concns. were approx. 0.01% were preliminary screened for antibacterial activity against Bacillus subtilis, Escherichia coli, Proteus vulgaris and Staphylococcus aureus.

Key words: BENZENECARBOXYLIC ACID, SUBSTITUTION REACTION, AMINO GROUP, MERCAPTO GROUP, ARYL GROUP, THIADIAZOLE P, PYRRODIAZOLE P, PYRRODIAZOLE P, FUSED RING COMPOUNDS, ANTIBIOTIC PROPERTY