- The reactions of hydroiodide of 2-amino-1-substituted guanidine derivatives with aromatic isothiocyanates
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In the reaction of hydroiodide of methyl ester of S-methylthio-semicarbazide with primary amines hydroiodides of 2-amino-1-substitutedguanidine were obtained (1). These compounds were then converted to respective 3-arylamino-4-substituted Δ2-1,2,4-triazoline-5-thione and 3- benzylamino-4-substituted Δ2-1,2,4 -triazoline-5-thione (2) in the reactions with isothiocyanates.
- Dobosz, Maria,Wujec, Monika
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p. 1135 - 1141
(2007/10/03)
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- Reaction of 4-Alkyl/arylthiosemicarbazides with Cyanamide
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The condensation of cyanamide with 4-alkyl/arylthiosemicarbazide hydrochlorides (I.HCl) results in the formation of 2-alkyl/arylamino-5-amino-1,3,4,-thiadiazoles (III) and 3-amino-4-alkyl/aryl-5-mercapto-1,2,4-triazoles (IV).
- Koshy, Lissamma,Joshua, C. P.
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p. 530 - 531
(2007/10/02)
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- Oxidation and Eliminative Cyclisation of S-Alkylisodithiobiureas
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Isothiocyanates condense with S-alkylisothiosemicarbazides to yield S-alkylisodithiobiureas.These undergo cyclisation to give 3-amino-5-mercapto-4-substituted-1,2,4-triazoles with the elimination of alkyl mercaptan on heating under neutral conditions, whereas under acidic conditions, by elimination of ammonia 5-alkylmercapto-2-substituted amino-1,3,4-thiadiazoles are formed.Condensation of isothiocyanates with thiosemicarbazides in the presence of alkali affords 1-substituted dithiobiureas.Alkylation of these dithiobiureas with alkyl halides results in the formation of 5-alkylmercapto-2-substituted-amino-1,3,4-thiadiazoles, any intermediateproduct not being isolable.On the other hand, oxidation of 1-substituted dithiobiureas with either hydrogen peroxide or iodine furnishes 2-amino-5-substituted-amino-1,3,4-thiadiazoles.
- Indukumari, P. V.,Joshua, C. P.,Rajan, V. P.
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p. 384 - 387
(2007/10/02)
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