50685-15-9Relevant academic research and scientific papers
α-Keto Acids as Triggers and Partners for the Synthesis of Quinazolinones, Quinoxalinones, Benzooxazinones, and Benzothiazoles in Water
Huang, Jian,Chen, Wei,Liang, Jiazhi,Yang, Qin,Fan, Yan,Chen, Mu-Wang,Peng, Yiyuan
, p. 14866 - 14882 (2021/10/25)
A general and efficient method for the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil. More importantly, these reactions can be conducted on a mass scale, and the products can be easily purified through filtration and washing with ethanol (or crystallized).
"Metal-Free" Nanoassemblies of AIEE-ICT-Active Pyrazine Derivative: Efficient Photoredox System for the Synthesis of Benzimidazoles
Dadwal, Shruti,Kumar, Manoj,Bhalla, Vandana
, p. 13906 - 13919 (2020/11/20)
Supramolecular nanoassemblies of an AIEE-ICT-active pyrazine derivative (TETPY) having strong absorption in the visible region and excellent transportability have been utilized as an efficient photoredox catalytic system for the synthesis of a variety of benzimidazoles having electron-withdrawing/electron-releasing/aliphatic groups under "metal-free"conditions. The reaction protocol involves the successful harvesting of visible light by TETPY assemblies to catalyze the coupling of o-phenylenediamine/substituted diamines and substituted aromatic/heterocyclic/aliphatic aldehydes under aerial conditions using mixed aqueous media as the reaction solvent. TETPY assemblies could activate aerial oxygen to generate superoxide for completing the vital proton abstraction step without the need for any external metal/base/oxidant. Moreover, all the products are purified by recrystallization from organic solvents. The TETPY assemblies also exhibited high efficiency in catalyzing the synthesis of 2-substituted benzothiazoles and quinazolines in excellent yields.
Method for synthesizing benzothiazole by microwave radiation of benzothioamide compound in aqueous phase
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Paragraph 0013; 0027, (2019/02/13)
The invention discloses a method for synthesizing benzothiazole by microwave radiation of a benzothioamide compound in an aqueous phase. The method includes the steps: adding the benzothioamide compound into the aqueous phase under microwave conditions; performing cyclization under alkaline conditions to generate the benzothiazole. The method for preparing the benzothiazole is environmentally friendly, simple and convenient in operation, safe, cheap and efficient. Compared with the prior art, the method is applicable to a lot of functional groups, high in yield, few in by-products, simple in operation, safe, low in cost and environmentally friendly.
Method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions
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Paragraph 0062; 0123, (2019/01/21)
The invention discloses a method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions. According to the method, glacial aceticacid is taken as a catalyst; at solvent-free room temperature conditions, physical grinding is adopted, reaction of 2-substituted arylamines (2-mercapto arylamine, 2-aminophenol, and o-phenylenediamine) and aromatic aldehydes is carried out using physical grinding. The method is friendly to the environment, is simple in operation, is safe, is low in cost, and is high in efficiency. Compared withthe prior art, the advantages are that: the method is suitable for a large amount of functional groups, yield is high, less by-product is generated, operation is simple, the method is safe, cost is low, and the method is friendly to the environment.
Controllable assembly of the benzothiazole framework using a CC triple bond as a one-carbon synthon
Huang, Yubing,Yan, Donghao,Wang, Xu,Zhou, Peiqi,Wu, Wanqing,Jiang, Huanfeng
supporting information, p. 1742 - 1745 (2018/02/21)
A concise and efficient protocol to assemble diverse benzothiazole derivatives in high yields was provided via copper catalyzed tandem cyclization with o-haloanilines, elemental sulfur and terminal alkynes as raw materials. In this protocol, C atoms on the CC triple bond were controllably involved in the construction of the benzothiazole framework and multiple carbon-heteroatom bonds through divergent routes.
Acylperoxycoumarins as ortho-C?H Acylating Agent via a Palladium(II)-Catalyzed Redox-Neutral Process
Ranjan Mohanta, Prakash,Banerjee, Arghya,Kumar Santra, Sourav,Behera, Ahalya,Patel, Bhisma K.
supporting information, p. 2047 - 2052 (2016/07/16)
An unprecedented palladium(II)-catalyzed biomimetic aliphatic acyl (-COR) group transfer was observed from acyl-α-peroxycoumarins to the ortho C?H sites of directing arenes. Here, the C?H activation is associated with a concomitant acyl group transfer via a Pd(II)-catalyzed, redox-neutral process. While methods for ortho aroylation (-COAr) are well documented ortho acylation (-COR) processes are scarce, hence the present redox-neutral method is most ideal for o-acylation of directing substrates. (Figure presented.) .
Catalyst-Free Synthesis of 2-Arylbenzothiazoles in an Air/DMSO Oxidant System
Hu, Renhe,Li, Xiaotong,Tong, Yao,Miao, Dazhuang,Pan, Qiang,Jiang, Zengqiang,Gan, Haifeng,Han, Shiqing
supporting information, p. 1387 - 1390 (2016/05/24)
A straightforward strategy for the synthesis of 2-arylbenzothiazoles from 2-aminothiophenol and aryl aldehydes in air/DMSO oxidant system has been developed. This reaction is operationally simple, proceeds without catalysts, tolerates a wide range of func
KI-catalyzed arylation of benzothiazoles from the coupling of aryl aldehydes with benzothiazoles in neat water
Gao, Yuyu,Song, Qiuling,Cheng, Guolin,Cui, Xiuling
supporting information, p. 1044 - 1047 (2014/02/14)
A KI-catalyzed oxidative coupling of benzothiazoles with aryl aldehydes has been developed using TBHP as an oxidant in neat water under metal free conditions. Various 2-aryl benzothiazoles were prepared in 36-79% yields for 28 examples. The mechanistic studies suggested that this transformation proceeded via a radical process. The Royal Society of Chemistry.
Weinreb amide as an efficient reagent in the one pot synthesis of benzimidazoles and benzothiazoles
Bommegowda, Yadaganahalli K.,Lingaraju, Gejjalagere S.,Thamas, Saji,Vinay Kumar, Koravangala S.,Pradeepa Kumara, Challanayakanahally S.,Rangappa, Kanchugarakoppal S.,Sadashiva, Marilinganadoddi P.
supporting information, p. 2693 - 2695 (2013/06/05)
One pot synthesis of 2-substituted benzimidazoles/benzothiazoles through condensation is followed by cyclization of Weinreb amide with o-diaminoarene or o-aminothiophenol is reported. In the presence of boron trifluoride etherate in 1,4-dioxane solvent, a high yield (75-94%) was achieved within 60 min. Weinreb amide shows high selectivity in the reaction, even in presence of other active functional groups such as carboxyl, halogen, cyano, and methoxy.
Trichloroisocyanuric acid (TCCA) as a mild and efficient catalyst for the synthesis of 2-arylbenzothiazoles
Xiao, Hui-Long,Chen, Jiu-Xi,Liu, Miao-Chang,Zhu, Dong-Jian,Ding, Jin-Chang,Wu, Hua-Yue
supporting information; experimental part, p. 170 - 171 (2010/02/16)
The condensation reaction of 2-aminothiophenol with aldehydes catalyzed by 1 mol % trichloroisocyanuric acid (TCCA) was investigated. As a result, a set of diverse 2-arylbenzothiazoles were obtained in good to excellent yields at room temperature. Copyrig
