2080-59-3Relevant articles and documents
Reinvestigation of o-phenylenediamine thermal cyclocondensation with thiosemicarbazide
Bakavoli,Rezaei Seresht,Rahimizadeh
, p. 273 - 274 (2006)
Thermal cyclocondensation of o-phenylenediamine with thiosemicarbazide at elevated temperature gave the 1,3-dihydro-2H-1,3-benzimidazole-2-thione not the 1,4-dihydro- 1,2,4-benzotriazine-3(2H)thione claimed by an earlier worker. Analytical and spectral data are given in support of this reinvestigtation.
Synthesis and crystal structures of benzimidazole-2-thione derivatives by alkylation reactions
El Ashry, El Sayed H.,Kilany, Yeldez El,Nahas, Nariman M.,Barakat, Assem,Al-Qurashi, Nadia,Ghabbour, Hazem A.,Fun, Hoong-Kun
, (2016)
Alkylated, benzylated and bromoalkylated benzimidazole-thione that intramolecularly heterocyclized to 3,4-dihydro-2H-[1,3]thiazino[3,2-a]benzimidazole were synthesized. The chemical structure of the synthesized product was characterized by Infra Red, 1H-NMR, 13C-NMR, and Mass spectroscopy. Furthermore, the molecular structures of 8 and 9 were confirmed by X-ray single crystallography in different space groups, Pbca and P21/c, respectively.
Slow, spontaneous degradation of lansoprazole, omeprazole and pantoprazole tablets: Isolation and structural characterization of the toxic antioxidants 3H-benzimidazole-2-thiones
Rajab,Touma,Rudler,Afonso,Seuleiman
, p. 749 - 754 (2013)
The spontaneous degradation of lansoprazole, omeprazole and pantoprazole tablets upon long-term and forced storage conditions was determined by high performance liquid chromatography (HPLC). The more abundant products could be isolated by liquid chromatography and their molecular weights determined by Mass Spectrometry (MS). Their structures, established according to their spectroscopic data, were compared to those of either the literature or of authentic samples. Thus lansoprazole led mainly to a mixture of 3H-benzimidazole-2-thione (2a) and 3H-benzimidazole-2-one (2c), omeprazole mainly to a mixture of 5-methoxy-3H-benzimidazole-2-thione (1a) and 2-hydroxymethyl-3, 5-dimethyl- 4-methoxypyridine (1b), and pantoprazole, to 5-difluoromethoxy-3H-benzimidazole-2-thione (3a) and 2-hydroxymethyl-3, 4-dimethoxypyridine (3b). Although some of the degradation products had already been observed under different conditions, the detection of benzimidazole-2- thiones is unprecedented and their involvement as possible physiological, yet toxic antioxidants must be emphasized. Plausible, unified mechanisms for the formation of the different degradation products observed herein and in previous papers from the literature are suggested.
A new strategy for the synthesis of 2-mercaptobenzazole derivatives by green chemistry metrics
Vessally, Esmail,Monfared, Aazam,Eskandari, Zahra,Abdoli, Morteza,Hosseinian, Akram
supporting information, p. 1 - 5 (2020/08/25)
A green and efficient method has been developed for the synthesis of 2-mercaptobenzazole derivatives via the reaction of commercially available aniline derivatives with low-cost and nontoxic potassium thiocyanate in water. The reactions proceeded smoothly under catalyst- and ligand-free conditions to give the corresponding products in good to excellent yields. The versatility, low cost, and environmental friendliness, in combination with high yields and easy work-up makes the procedure noteworthy.
A Highly Efficient Synthesis of 2-Benzimidazolthiones and Their Congeners under Mild Conditions
Li, Wei-wei,Zheng, Hui
, p. 175 - 181 (2019/04/17)
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Synthesis Of di- and tri-substituted thiourea derivatives in water using choline chloride–urea catalyst
Tavakol, Hossein,Mahmoudi, Amir,Ranjbari, Mohammad-Amin
, p. 113 - 123 (2018/10/24)
In this work, di- and tri-substituted thiourea derivatives have been synthesized via a one-pot, three-component reaction from carbon disulfide and aliphatic or aromatic amines using choline chloride-urea deep eutectic solvent as a catalyst in water. Both cyclic and acyclic thiourea derivatives with two or three substituents were synthesized successfully. The reactions were done at 25–100°C, using 5–20 mol% catalyst, in 3–5 h and the GC-Mass yields were between 60% and 95%. All products were characterized using FT-IR, 1H-NMR, 13C-NMR, GC-MS and melting point analyses. The results showed that both water and the DES have important effects on the yield and the rate of this reaction and both of them are necessary to obtain higher yields in less time. The extra experiment, which was designed to study the mechanism of the reaction, showed that an isothiocyanate intermediate was formed in the reaction. Finally, the results showed that by the increase of the amine's nucleophilicity, the reaction occurs faster and gives higher yield.
