The key intermediate 4-amino-3-mercapto-1, 2, 4-triazoles (1) is prepared by reacting with methyl paraben carbohydrazide and CS2 to yield potassium dithiocarbazinate salt. The salt upon reaction with hydrazine hydrate will yield the compound(1).The title compounds 4-(6-phenyl-[1,2,4] triazole [3,4-b] [1,3,4] thiadiazole-3-yl)-phenol derivatives were prepared by reacting 4-amino-3-mercapto-1,2,4-triazole(1) with aromatic acids in the presence of phosphorous oxychloride medium. All the new compounds were evaluated for in-vitro antioxidant and antifungal activities. The new compounds were assigned on the basis of IR, NMR and mass spectral data.