Thiosemicarbazides and Selenosemicarbazides

Synthesis.—The principal synthetic method in the field of thiosemicarbazide chemistry is the reaction of isothiocyanates with hydrazines, and new thiosemi- 

Anthoni, B. Mynster Dahl, H. Eggert, C. Larsen, and P. H. Nielsen, Acta Chem. Scand. B), 1976, 30, 71. 

Synthesis.—The traditional route to thiosemicarbazides is based on the reaction between isothiocyanates and hydrazines, and, obviously, a great number of recent, relevant papers have reported on the application of this reaction in the synthesis of new compounds of this class. Of 

NN-disubstituted hydrazones. Heterocyclic compounds containing the l,2,4-triazoline-3-thione structure were formed in reactions between ethoxy-carbonyl isothiocyanate and hydrochlorides of amidrazones, phenyl isothiocyanate and anhydro-l-phenylimino-2,4,5-triphenyl-l,2,3-triazoline hydroxide, phenylhydrazones and thiocyanic acid, aroylhydrazines and 

A new route to isothiocyanatoimines (352) has been found in the reaction of triethylammonium 3-alkylidenedithiocarbazate with thiophosgene at 0°C. The products (352) were, however, rather unstable, and reacted instantly with any methylamine present to produce the thiosemicarbazones (353). Dahl and his co-workers recently described the synthesis of PP-disubstituted thiophosphinoylthioformhydrazides (354) by the reaction 

A series of papers dealing with the preparation and properties of metal complexes of l-coumariloyl-4-arylthiosemicarbazides, N-phenylthiocar-bamoyl-N -guanylhydrazine, 4-aryl-3-thiourazoles, S-methyl-dithizone, and arylazothioformamides may be of interest to workers in that field. 

Reactions.— Recent studies of the nucleophilic reactivity of the thiocarbonyl sulphur atom of thiosemicarbazides have dealt largely with heterocycles containing the thiosemicarbazide or the thiosemicarbazone moiety, and comprise methylation reactions of 3-methyl-l,2,4-triazole-5-thiones and 

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