24255-48-9Relevant academic research and scientific papers
A Mild Synthesis of 2-Substituted Benzothiazoles via Nickel-Catalyzed Intramolecular Oxidative C-H Functionalization
Gao, Ming-Yuan,Li, Jing-Hang,Zhang, Shi-Bo,Chen, Li-Jun,Li, Yue-Sheng,Dong, Zhi-Bing
, p. 493 - 500 (2020)
A highly efficient synthetic method for the preparation of 2-aminobenzothiazoles starting from arylthioureas has been reported. By using a nickel catalyst, arylthioureas undergo intramolecular oxidative C-H bond functionalization, giving the desired 2-aminobenzothiazoles in good to excellent yields. This protocol features an inexpensive catalyst, low catalyst loading, mild reaction conditions, a short reaction time, and good to excellent yields, and it can be scaled up easily to a gram scale with almost no yields decreasing.
Palladium-catalyzed tandem synthesis of 2-aminobenzothiazoles starting from unreactive 2-chloroanilines
Xu, Wan,Zeng, Meng-Tian,Liu, Min,Liu, Xing,Chang, Cai-Zhu,Zhu, Hui,Li, Yue-Sheng,Dong, Zhi-Bing
, p. 641 - 643 (2017)
A simple and efficient protocol for the synthesis of 2-aminobenzothiazole derivatives is described. 2-Chloroanilines were treated with thiocarbamoyl chloride in the presence of Pd(dba)2 and t-BuOK to afford the corresponding 2-amino-benzothiazoles in good to excellent yield via a tandem manner.
Palladium-Catalyzed Synthesis of 2-Aminobenzothiazoles through Tandem Reaction
Xu, Wan,Zeng, Meng-Tian,Liu, Min,Liu, Sha-Sha,Li, Yue-Sheng,Dong, Zhi-Bing
, p. 3084 - 3090 (2017)
A variety of 2-aminobenzothiazoles were synthesized by using 2-chloroanilines and dithiocarbamates through a tandem approach in the presence of Pd(PPh 3) 4 and t -BuOK. The facile and efficient protocol enabled the reaction to proceed at a good rate with excellent yields.
Ionic Reactivity of 2-Isocyanoaryl Thioethers: Access to 2-Halo and 2-Aminobenzothia/Selenazoles
Dong, Jinhuan,Hu, Junlin,Liu, Xiaoli,Sun, Shaoguang,Bao, Lan,Jia, Mengying,Xu, Xianxiu
, p. 2845 - 2852 (2022/02/23)
An ionic cascade insertion/cyclization reaction of thia-/selena-functionalized arylisocyanides has been successfully developed for the efficient and practical synthesis of 2-halobenzothiazole/benzoselenazole derivatives. This synthetic protocol, incorporating a halogen atom when forming the five-membered ring of benzothia/selenazoles, is different from the existing ones, where halogenation of the preformed benzothia/selenazole precursors happens. Additionally, a facile access to 2-aminobenzothiazoles is also achieved by the one-pot cascade reaction of 2-isocyanoaryl thioethers, iodine, and amines.
Copper(ii) ions supported on functionalized graphene oxide: an organometallic nanocatalyst for oxidative amination of azolesviaC-H/C-N bond activation
Behzadi, Masoumeh,Mahmoodi Hashemi, Mohammad,Roknizadeh, Mostafa,Nasiri, Shahrokh,Ramazani Saadatabadi, Ahmad
supporting information, p. 3242 - 3251 (2021/02/26)
Graphene oxide (GO) was chemically modified withpara-aminobenzoic acid (PABA) to immobilize copper(ii) ions on its surface and used as a nanocatalyst for the oxidative C(sp2)-H bond amination reaction. A practical method to prepare Cu2+supported onpara-aminobenzoic acid grafted on GO was reported. The prepared Cu2+@GO/PABA was characterized by FT-IR, XRD, SEM, AFM, TEM, UV-Vis, and ICP techniques. The results showed that the morphology, distribution, and loading of copper ions could be well-adjusted by grafting of PABA on GO. Moreover, just 2 mol% of Cu2+@GO-PABA could catalyze the C-H activation reaction of benzoxazole and benzothiazole with secondary amines in >94% yields. Also, the catalyst showed very good recyclability and much less leaching of the Cu into the reaction solution. The high activity of Cu2+@GO-PABA can be ascribed to the good synergistic effects of Cu2+andpara-aminobenzoic acid grafted on graphene oxide.
Room-Temperature Amination of Chloroheteroarenes in Water by a Recyclable Copper(II)-Phosphaadamantanium Sulfonate System
Dandela, Rambabu,Desai, Aman A.,Kapdi, Anant R.,Kori, Santosh,Maity, Dilip K.,Parmar, Udaysinh,Somvanshi, Dipesh
, p. 8900 - 8925 (2021/07/20)
Buchwald-Hartwig amination of chloroheteroarenes has been a challenging synthetic process, with very few protocols promoting this important transformation at ambient temperature. The current report discusses about an efficient copper-based catalytic system (Cu/PTABS) for the amination of chloroheteroarenes at ambient temperature in water as the sole reaction solvent, a combination that is first to be reported. A wide variety of chloroheteroarenes could be coupled efficiently with primary and secondary amines as well as selected amino acid esters under mild reaction conditions. Catalytic efficiency of the developed protocol also promotes late-stage functionalization of active pharmaceutical ingredients (APIs) such as antibiotics (floxacins) and anticancer drugs. The catalytic system also performs efficiently at a very low concentration of 0.0001 mol % (TON = 980,000) and can be recycled 12 times without any appreciable loss in activity. Theoretical calculations reveal that the π-acceptor ability of the ligand PTABS is the main reason for the appreciably high reactivity of the catalytic system. Preliminary characterization of the catalytic species in the reaction was carried out using UV-VIS and ESR spectroscopy, providing evidence for the Cu(II) oxidation state.
Method for catalytically synthesizing 2-aminobenzothiazole derivative by N, N-dimethylthio carbamoyl chloride under microwave radiation
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Paragraph 0029, (2018/04/28)
The invention discloses a method for catalytically synthesizing a 2-aminobenzothiazole derivative under microwave radiation. A catalytic amount of copper iodide serving as a catalyst, 8-hydroxyquinoline serving as a ligand, potassium hydroxide serving as an auxiliary catalyst, 2-halogenated aniline, a derivative of 2-halogenated aniline, powdered sulfur, an N, N-dimethylthio carbamoyl chloride derivative and pyridine are added into a reaction vessel, the reaction vessel is placed into a microwave reactor, reaction is performed at a certain temperature and under a certain power, vacuum concentration is performed after a certain time, and a product is purified by column chromatography. According to the method, raw materials are novel, operation is simple and convenient, and the 2-aminobenzothiazole derivative is efficiently prepared. Compared with the prior art, the method has the advantages that reaction speed is obviously increased as compared with conventional heating, reaction conditions are mild, and the method is simple in operation, high in yield, safe, low in cost and environmentally friendly.
Solid Supported Nano Structured Cu-Catalyst for Solvent/Ligand Free C2 Amination of Azoles
Dutta, Pratip Kumar,Sen, Subhabrata,Saha, Debasree,Dhar, Basabbijayi
supporting information, p. 657 - 665 (2018/02/14)
Ligand- and solvent-free catalytic conditions that harness a nanostructured–CuI catalyst encapsulated in TiO2 has been reported for C2-amination of azoles (benzothiazole, benzoxazole and thiazole). The reaction is highly regioselective. The catalyst is robust, inexpensive and can be recycled up to four times. This strategy was further used for the synthesis of a small molecule with anti-HIV and anti-tumor properties.
Copper(II)-Promoted Cascade Synthesis of 2-Aminobenzothiazoles Starting from 2-Iodoanilines and Sodium Dithiocarbamates
Zhu, Hui,Zhang, Shi-Bo,Liu, Xing,Cheng, Yu,Peng, Han-Ying,Dong, Zhi-Bing
supporting information, p. 5711 - 5716 (2018/10/31)
A facile and efficient formation of 2-aminobenzothiazoles by a copper(II)-promoted one-pot cascade process was developed. The desired 2-aminobenzothiazoles were synthesized in good to excellent yields (up to 97 %) in the presence of Cu(OAc)2 an
Copper catalyzed synthesis of benzoxazoles and benzothiazoles via tandem manner
Xu, Wan,Zeng, Meng-Tian,Liu, Sha-Sha,Li, Yue-Sheng,Dong, Zhi-Bing
supporting information, p. 4289 - 4292 (2017/10/12)
A useful protocol for the preparation of substituted 2-aminobenzoxazoles and 2-aminobenzothiazoles was presented. Under the catalysis of copper, 2-aminophenols or 2-aminothiophenols reacted with thiocarbamoyl chlorides via a tandem manner, furnishing a series of 17 benzoheterocycles smoothly with good to excellent yields (70–91%). The broad substrate scope, short reaction time, mild react conditions, easy performance and nice yields make this approach attractive, showing its practical synthetic value for the preparation of some biologically or pharmaceutically active compounds.
