4-amino-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol have been prepared by treating isonicotinic acid hydrazide (1NH) successively with alcoholic KOH, CS₂ and hydrazinehydrate. These triazole derivatives were employed in the synthesis of 4-[substituted phenyl methylidene amino]-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol (1a-o) and N-[substituted phenyl]-3-pyridin-4-yl [1,2,4] triazolo [3,4-b] [1,3,4] thiadiazol-6-amine (2a-c). Some of they were found to be potential antimicrobial agents.
Graphical Abstract : A series of 4-[substituted phenyl methylidene amino]-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol and N-[substituted phenyl]-3-pyridin-4-yl[1,2,4] triazolo[3,4-b][1,3,4-]thiadiazol-6-amine derivatives of quinolin-8-ol have been synthesized and evaluated for their antimicrobial activities.