Yield:471-32-9 80%

Reaction Conditions:

with hydrazine hydrate monohydrate in ethanol at 0 - 5; for 1 h;

Steps:

4-Amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (1).

Carbon disulfide, 76 mL (1 mol), was added to a solution of 100 mL (2 mol) of 85% hydrazine hydrate in 300 mL of ethanol, and the mixture was stirred for 1 h at 0-5 °C. The white solid was filtered off and washed with ethanol and diethyl ether to yield 86.5 g (80%) of hydrazinecarbodithioic acid, mp 122-124 °C. The product, 21.6 g (0.2 mol) was dissolved in distilled water (200 mL) containing excess hydrazine hydrate, and the mixture was refluxed for 45 min. The progress of the reaction was monitored by TLC (n-hexane-EtOAc, 4 : 1). After completion of the reaction, the mixture was cooled, and the white solid was filtered off and recrystallized from 96% ethanol to isolate hydrazinecarbothiohydrazide in excellent yield with high purity. The product, 10.6 g (0.1 mol) was added to a mixture of 100 mL of glacial acetic acid and 100 mL of water, and the mixture was refluxed for 4 h. After completion of the reaction, the mixture was cooled, and the resulting dough-like material was filtered off and recrystallized from H₂O to obtain 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (1) as transparent crystals with mp 210-220 °C; yield 75%.

References:

Kazeminejad;Pourshamsian;Hatamjafari;Shiroudi;Oliaey [Russian Journal of Organic Chemistry,2019,vol. 55,# 10,p. 1609 - 1615][Zh. Org. Khim.,2019]