Hydrazinecarbothioamide group in the synthesis of heterocycles

Abstract

The review summarizes recent literatures dealing with hydrazinecarbothioamide group in thiocarbohydrazides and other derivatives including their physical and chemical properties along with their applications in the synthesis of heterocycles.

Reaction of N,N-disubstituted hydrazinecarbothioamides with 2-bromo-2-substituted acetophenones

“…18,19 Previously, we utilized by N,N'-disubstituted-hydrazinecarbothioamides in heterocyclic synthesis, such as 1,3-thiazin-2-ylidene-substituted hydrazides and 1,2,4-triazolo [3,4-b]-1,3-thiazine-5-carboxylates 20 . Continuation of our research program included the synthesis of various thiazoles, [21][22][23][24][25][26] we herein report the results of our investigation on the reactions of symmetrical hydrazinecarbothioamides 1a-d with 2-bromoacetophenones 2a,b.…”

Rapid and Facile Synthesis of Spiro[Indole-3,3′-[1,2,4]Triazol]-2(1H)-Ones

“…Melting points are uncorrected values. 1 H NMR and 13 C NMR spectra (Bruker AM 400, 1 H: 400.13 MHz, 13 C: 100.6 MHz) were obtained from CDCl 3 solutions; the chemical shifts (δ) are given relative to internal standard TMS, and coupling constants (J) are in Hz. For preparative thin layer chromatography (PLC), glass plates (20 × 48 cm) were covered with a slurry of silica gel Merck PF 254 and air dried using the solvents listed for development.…”

“…The 1 H NMR spectrum of 4a showed the fused phenyl protons at d H = 7.90 (t, 2 H, J = 7.0 Hz) and 7.85 (d, 2 H, J = 7.8 Hz), whilst two NH-protons were observed as broad singlets at d H = 6.5 and 8.0. The observed 13…”

“…The structure assignment of compounds 4a-e is well established using traditional spectroscopic tools such as IR, NMR ( 1 H, 13 C) and mass spectra, in addition to elemental analyses. Compounds 4a-e showed IR absorption peaks for NH groups at n max = 3350-3330 cm -1 along with broad bands at n max = 1680-1695 cm -1 corresponding to the carbonyl groups.…”

Formation of thiadiazole, thiadiazine, thiadiazepine and pyrazole derivatives in the reaction of 2,4-disubstituted thiosemicarbazides with tetracyanoethylene

“…They are also ideal candidates and valuable building blocks for the synthesis of different families of heterocyclic compounds. [14][15][16][17] Many diseases such as cancer may be treated by using thiosemicarbazides and thus their development is still in progress. 18,19 It has been reported that 4-substituted thiosemicarbazides 1a-c (Scheme 1) reacted with tetracyanoethylene (TCNE, 2) in ethyl acetate with admission of air to give thiadiazepine and pyrazolothiadiazole derivatives as well as 3-amino-4,5-dicyanopyrazole.…”