7466-32-2Relevant academic research and scientific papers
A highly regioselective synthesis of 2-aryl-6-chlorobenzothiazoles employing microwave-promoted Suzuki-Miyaura coupling reaction
Heo, Yeon,Song, Young Seob,Kim, Bum Tae,Heo, Jung-Nyoung
, p. 3091 - 3094 (2006)
Suzuki-Miyaura coupling reactions of 2,6-dichlorobenzothiazole with arylboronic acids, promoted by microwave heating, efficiently produce 2-aryl-6-chlorobenzothiazoles in a highly regioselective manner. This process serves as the foundation for a simple m
Recyclable copper-catalyzed cyclization of o-haloanilides and metal sulfides: An efficient and practical access to substituted benzothiazoles
Cai, Mingzhong,Hao, Wenyan,Huang, Wencheng,Ye, Qian
, (2022/01/19)
An efficient heterogeneous copper-catalyzed cyclization of o-haloanilides and metal sulfides has been achieved via the C–S coupling in DMF at 80 or 140 °C in the existence of an MCM-41-bound NHC-Cu(I) catalyst and then intramolecular condensation, delivering a wide range of substituted benzothiazoles in mostly good to high yields. This new MCM-41-NHC-CuI complex can facilely be obtained by a two-step procedure starting from easily accessible and inexpensive reagents and reused more than seven times without any significant loss of its catalytic efficiency. The present protocol has been successfully applied to the gram-scale synthesis of two antitumor agents 5F203 and PMX 610.
Graphene oxide-catalyzed synthesis of benzothiazoles with amines and elemental sulfur via oxidative coupling strategy of amines to imines
Duan, Dehao,Han, Xiaowei,He, Haiping,Huang, Panpan,Li, Hong,Nie, Liang,Peng, Xiangjun,Tang, Bo,Wang, Hanyu,Wei, Yifei
, (2022/01/13)
The graphene oxide-catalyzed coupling and cyclization reactions of primary amines with elemental sulfur was developed to afford various optically property benzothiazoles. This coupling and cyclization strategies proceeded under the oxidant system graphene oxide/O2 and constructed carbon-heteroatom (N, S) bonds with amines and elemental sulfur. Due to benzothiazoles as common chromophores, these products exhibited intriguing fluorescence properties, including outstanding Stokes shifts (up to 161 nm) and quantum yields (up to 74%). Utilizing the products’ unique fluorescence response in different solvents, β-naphthothiazole 4a showed excellent aggregation-induced emission properties in 1,2-dichloroethane, which was 60 times higher than in tetrahydrofuran.
Photocatalyst- And Transition-Metal-Free Visible-Light-Promoted Intramolecular C(sp2)-S Formation
Wang, Hao,Wu, Qi,Zhang, Jian-Dong,Li, Hai-Yan,Li, Hong-Xi
, p. 2078 - 2083 (2021/04/05)
A photocatalyst- and transition-metal-free visible-light-induced cyclization of ortho-halothiobenzanilides has been developed. Upon irradiation with visible light, substrates undergo dehalogenative cyclization to 2-aryl benzothiazoles with high efficiency and selectivity. This photocyclization exhibits a high tolerance to various functional groups, is applicable for the synthesis of 2-alkyl benzothiazoles, and is easy to set up for gram-scale reaction.
Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
supporting information, p. 4843 - 4848 (2021/06/28)
A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
Method for preparing benzothiazole compound from visible light promoted N-(2-bromophenyl) thioamide
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Paragraph 0040-0042, (2021/06/22)
The invention discloses a method for preparing a benzothiazole compound from N-(2-bromophenyl) thioamide under the promotion of visible light. Specifically, under the protection of inert gas, according to the molar ratio of N-(2-bromophenyl) thioamide to inorganic base being 1: 0.5, reactants are added into a reaction container provided with a stirring device, then dimethyl sulfoxide is added, and stirring reaction is carried out for 2-24 hours at room temperature under the irradiation of visible light to obtain the benzothiazole compound. Under the condition of not adding any photosensitizer or transition metal catalyst, sodium phosphate is used as alkali, and under the irradiation of a 45W household compact fluorescent lamp, a series of intramolecular cross-coupling reactions of N-(2-bromophenyl) thioamide are realized. In addition, the benzothiazole compound can be obtained with high yield. The whole process is green, efficient and easy to operate, and the method is a good method for synthesizing the benzothiazole compound.
Preparation method of 2-substituted benzothiazole
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Paragraph 0046-0051, (2020/11/09)
The invention discloses a preparation method of 2-substituted benzothiazole, and belongs to the field of organic chemical synthesis. The preparation method of the 2-substituted benzothiazole specifically comprises the following steps: by taking an N-aryl thioamide compound as a raw material and taking graphite-phase carbon nitride (g-C3N4) prepared by urea thermal polymerization condensation as aphotocatalyst, carrying out a cyclization reaction under a mild condition to prepare the 2-substituted benzothiazole. The method has the advantages of simple operation, cheap and easily available catalyst, mild reaction conditions, wide substrate application range, no strong oxidant and no metal residue, and provides an economical, practical, green and environment-friendly new method for synthesisof 2-substituted benzothiazole widely applied to the fields of medicines, dyes, pesticides and the like.
Riboflavin as Photoredox Catalyst in the Cyclization of Thiobenzanilides: Synthesis of 2-Substituted Benzothiazoles
Bouchet, Lydia M.,Heredia, Adrián A.,Argüello, Juan E.,Schmidt, Luciana C.
supporting information, p. 610 - 614 (2020/01/31)
Benzothiazoles are synthesized from thiobenzanilides using riboflavin as a photosensitizer and potassium peroxydisulfate as a sacrificial oxidizing agent under visible light irradiation. The methodology accepts a broad range of functional groups and affords the 2-substituted benzothiazoles by transition-metal-free organic photoredox catalysis under very mild conditions.
Copper-Catalyzed Aerobic Oxidation of Amines to Benzothiazoles via Cross Coupling of Amines and Arene Thiolation Sequence
Kim, Jihyeon,Oh, Kyungsoo
supporting information, p. 3576 - 3582 (2020/08/05)
A one-pot three-component synthesis of benzothiazoles has been developed using the copper-catalyzed aerobic cross coupling of amines followed by arene thiolation using elemental sulfur. The dual roles of elemental sulfur and CuCl(OH)-TMEDA in the aerobic amine oxidation and the aniline thiolation enable the facile access to benzothiazole derivatives from readily available starting materials. The operational simplicity of the current promiscuous catalyst system suggests the high synthetic potential in the preparation of heterocyclic compounds. (Figure presented.).
Method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions
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Paragraph 0062; 0177, (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.
