1.2.4- Triazolidine-3,5-dithione, 4-amino

The structure of these products though has been called into question. Recently (277, 204 it has been shown by means of independent synthesis, chemical behaviour and spectral analysis that the product of the reaction of thiocarbohydrazide with carbon disulfide is 4-amino-l, 2,4-triazolidine-3,5-dithione (LIV). 

Tliiocarbohydrazide with two equivalents of carbon disulfide in boiling pyridine gives some 40% yield of 4-amino-l,2,4-triazolidine-3,5-dithione (LIV). Simultaneously some 40% of 2,3.5,d-tetrah5 dro-l,2,4-triazolo[3,4-b]-l,3,4-thiadiazole-3,6-dithione (LV) is obtained. This product is formed through cyclization (of the type mentioned in Section 1.7) of the intermediate N-(2-thioxo-z]4-1,3,4-thiadiazolin-5-yl)-dithiocarbazate. 

As was mentioned in Section 1.8, thiocarbohydrazide reacts with carbon disulfide to give 4-amino-1,2,4-triazolidine-3,5-dithione (LIV) with liberation of hydrogen sulfide. Phenylthiocarbohydrazide, however, forms an exception to this rule and gives S-phenylhydrazino-J -... 

An early claim of the synthesis of l,3,4-thiadiazolidine-2,5-dione by the action of boiling hydrochloric acid on the substituted bithiourea PhNHNHC(S)-NHNHC(S)NHPh has been disproved, and the product identified as 4-(p-amino-phenyl)-l,2,4-triazolidine-3,5-dithione. ... 

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