86601-29-8Relevant academic research and scientific papers
Potassium Periodate Mediated Oxidative Cyclodesulfurization toward Benzofused Nitrogen Heterocycles
Duangkamol, Chuthamat,Pattarawarapan, Mookda,Phakhodee, Wong
, p. 1981 - 1990 (2020/07/03)
A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho -substituted anilines bearing N, N -, N, O -, and N, S -bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole series were rapidly accessible in good to excellent yields. The protocol can accommodate various substituents on both substrates while allowing more efficient, greener, and operational simpler process relative to other oxidative coupling reactions. Tetracyclic quinazolinone derivatives were also afforded in high yields in a single preparative step and chromatography-free.
Copper-promoted one-pot approach: Synthesis of benzimidazoles
Adil, Syed Farooq,Alduhaish, Osamah,Assal, Mohamed E.,Bollikolla, Hari Babu,Gollapudi, Ravi Kumar,Murthy Boddapati, S. N.,Nurbasha, Sharmila,Siddiqui, Mohammed Rafiq H.,Tamminana, Ramana
, (2020/04/24)
A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C-N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/nucleophilic substitution and a subsequent domino intra and intermolecular C-N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products.
Copper-Catalyzed C NH2Arylation of 2-Aminobenzimidazoles and Related C-Amino-NH-azoles
Rao, Desaboini Nageswar,Rasheed, Sk.,Kumar, Karampoori Anil,Reddy, Annem Siva,Das, Parthasarathi
supporting information, p. 2126 - 2133 (2016/07/16)
A copper(II)-catalyzed selective C NH2arylation of 2-aminobenzimidazoles and related C-amino-NH-azoles was achieved in presence of 2,2′-bipyridine and cesium carbonate at 60 °C under open air conditions and this is first method for the copper-catalyzed selective C NH2arylation in the presence of other reactive nucleophilic sites. Previously unexplored heteroaromatics possessing multiple nucleophilic sites that are selectively arylated at the C NH2position are obtained, providing an exceptional tool for rapid delivery of a diverse array of medicinally important C NH(aryl) derivatives of aminoazoles without any protection/deprotection of ring N H bonds. It is first example for the selective C NH2arylation of 5-aminoindazole, 4-aminopyrazole, 5-aminopyrazole, 9H-purine-6-amine, and 1H-pyrazolo[3,4-d]pyrimidin-4-amine derivatives. (Figure presented.) .
PROCESS FOR PREPARING 2-ARYLAMINO OR HETEROARYLAMINO SUBSTITUTED BENZIMIDAZOLE COMPOUNDS
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Page/Page column 10, (2011/02/24)
The present invention is related to a process for preparing 2-arylamino or heteroarylamino substituted benzimidazole compounds.
Phosphonium-mediated cyclization of N-(2-aminophenyl)thioureas: Efficient synthesis of 2-aminobenzimidazoles
Wan, Zhao-Kui,Ousman, Erena Farah,Papaioannou, Nikolaos,Saiah, Eddine
supporting information; experimental part, p. 4149 - 4152 (2011/09/19)
BOP efficiently promoted the phosphonium-mediated cyclization of thioureas, leading to a convenient synthesis of 2-aminobenzimidazoles. Compared to conventional methods, the reactions were complete at room temperature with times ranging from a few minutes
One-pot synthesis of five and six membered N, O, S-heterocycles using a ditribromide reagent
Yella, Ramesh,Patel, Bhisma K.
scheme or table, p. 754 - 763 (2010/11/03)
In a one-pot procedure, bromine less brominating reagent 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been utilized as an efficient desulfurizing agent for the construction of a library of heterocycles containing N, O, and S starting from aryl/alkyl isothiocyanates. In this approach, aryl/alkyl isothiocyanate reacts with o-phenylenediamine (o-PD), o-aminophenol, and o-aminothiophenol to form their monothiourea which on desulfurization with EDPBT led to the formation of corresponding 2-aminobenzimidazoles, 2-aminobenzoxazoles, and 2-aminobenzothiazoles, respectively. An interesting regioselectivity was observed for unsymmetrical thiourea having a naphthyl moiety on the one side and an ortho amino or an ortho hydroxy phenyl group on the other side giving a completely different product which is mainly dependent on the nature of the nucleophiles (-OH or -NH 2). Further, the bis-thioureas resulted from the aliphatic 1,2-diamine with 2 equiv of aryl isothiocyanates on treatment with EDPBT gave imidazolidenecarbothioamides, whereas bis-thioureas resulted from aromatic 1,2-diamine yielded benzimidazoles with concurrent expulsion of an isothiocyanate unit. This method is simple and applied to various substrates which are amenable to bromination that reveals the desulfurizing ability of EDPBT predominating over its brominating ability. Finally, the spent reagent EDPDB can be recovered, regenerated, and reused without any loss of activity.
Novel synthesis of 2-aminobenzimidazoles from isoselenocyanates
Xie, Yuanyuan,Zhang, Fan,Li, Jianjun,Shi, Xiangjun
supporting information; experimental part, p. 901 - 904 (2010/07/06)
An efficient one-pot procedure for the synthesis of 2-aminobenzimidazoles from isoselenocyanates and various substituted diamines is described. Precipitation of elemental selenium from the reaction mixture greatly simplifies the purification procedure and also allows it to be re-used for preparation of isoseleno?cyanates. A possible mechanism for the formation of 2-aminobenzimidazoles is proposed. Georg Thieme Verlag Stuttgart - New York.
Desulfurization mediated by hypervalent iodine(III): A novel strategy for the construction of heterocycles
Ghosh, Harisadhan,Yella, Ramesh,Nath, Jayashree,Patel, Bhisma K.
scheme or table, p. 6189 - 6196 (2009/05/27)
The desulfurization ability of diacetoxyiodobenzene (DIB) has been explored in the preparation of isothiocyanates from the corresponding dithiocarbamate salts. The in situ generated isothiocyanates reacted with o-phenylenediamine and o-aminophenol to form monothioureas, which, on treatment with a further equivalent of DIB in one pot, gave benzimidazoles and aminobenzoxazoles, respectively. Aliphatic 1,2-diamines on reaction with 2 equiv. of isothiocyanate followed by treatment with DIB gave imidazolidenecarbothioamides, whereas the treatment of aromatic 1,2-diaminebis(thioureas) yielded benzimidazoles with the concurrent formation of isothiocyanate. The driving force for the formation of the latter is the aromatization of the product. The use of DIB makes these methods simpler and more efficient, giving high yields of the desired products in one pot. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
A one-pot method for the synthesis of 2-aminobenzimidazoles and related heterocycles
Cee, Victor J.,Downing, Nicholas S.
, p. 3747 - 3750 (2007/10/03)
A rapid and efficient one-pot method for the synthesis of 2-aminobenzimidazoles and related heterocycles is described. The reaction is mediated by a polymer-supported carbodiimide, which simplifies product isolation. The scope and limitations of this method are described.
