Thiosemicarbazides undergo different cyclization reactions to give five membered heterocycles. The product of cyclization depends on the reagent used. This cyclization leads to the formation of 1, 3, 4-oxadiazole, 1, 3, 4-thiadiazole and 1, 2, 4-triazole derivatives. The reaction of thioglycolyl hydrazide derivatives of the 1, 2, 4-triazole compounds was discussed. The activity against hepatitis B virus (HBV) has been tested.
![ethyl [4-phenyl-5-(N-phenylamino)methyl-1,2,4-triazol-3-yl]thioglycolate结构式](https://image.chemsrc.com/caspic/039/680594-23-4.png)
![2-{[5-(Anilinomethyl)-4-phenyl-4H-1,2,4-triazol-3-yl]thio}acetohydrazide结构式](https://image.chemsrc.com/caspic/463/680594-25-6.png)
