17930-02-8Relevant articles and documents
Microwave-assisted preparation of 2-substituted benzothiazoles
Rostamizadeh, Shahnaz,Housaini
, p. 1321 - 1326 (2005)
2-Substituted benzothiazoles (3a-h) were prepared from the condensation reaction of 2-aminothiophenol 1 with aldehydes 2 in the presence of P-Ts-OH and graphite on the surface of solid mineral supports without using any oxidizing agent under microwave irr
Synthesis of amidine and bis amidine percursors
Singhal, Nidhi,Johar, Monika,Lown,Sondhi
, p. 81 - 92 (2001)
The reactions of substituted o-phenylene diamines, o-aminophenol, o-aminothiophenol, 3,4-diaminopyridine with p-cyanobenzaldehyde by refluxing in nitrobenzene gave corresponding benzimidazole, benzoxazole, benzthiazole and imidazopyridine derivatives Ia,b
Fast and high-efficiency synthesis of 2-substituted benzothiazoles via combining enzyme catalysis and photoredox catalysis in one-pot
Yang, Zeng-Jie,Gong, Qing-Tian,Yu, Yuan,Lu, Wei-Fan,Wu, Zhe-Ning,Wang, Na,Yu, Xiao-Qi
supporting information, (2021/01/14)
An efficient and green method, combining enzymatic and visible-light catalysis for synthesis of the widely applicable 2-substituted benzothiazoles, has been developed. This method features a relay catalysis protocol consisting of biocatalytic promiscuity
Ultrasound-assisted efficient and green synthesis of 2-substituted benzothiazoles under solvent-free condition using recyclable sulfated tungstate
Pise, Ashok S.,Ingale, Ajit P.,Dalvi, Navnath R.
supporting information, p. 3629 - 3641 (2021/10/12)
Sulfated tungstate catalyzed an efficient and ecofriendly protocol has been described for the synthesis of 2-substituted benzothiazoles. The corresponding benzothiazoles were obtained using a condensation reaction of 2-aminothiophenol with various aldehydes under ultrasound irradiation at room temperature. Various functional groups on the 2-aminothiophenol as well as on the aldehydes were tolerated to provide 2-substituted benzothiazoles derivatives in excellent yields. The faster reaction rate, solvent-free or mild reaction conditions, wide functional group compatibility, excellent yields, easy work-up procedure, and excellent catalyst recyclability are the advantages of this protocol. These advantages make this process more practicable, cost-effective, and environmentally benign.
An efficient rapid synthesis of benzoxazoles and benzothiazoles using pma.Sio2 at room temperature under heterogeneous conditions
Sudhakar, Chithaluri,Shekhar, Vanam,Shyamsunder, Manchi,Suryakumari, Adurthi,Manojkumar, Vala
, p. 583 - 587 (2021/09/30)
Treatment of 2-aminophenol (or 2-aminothiophenol) with aromatic aldehydes in the presence of phosphomolybdic acid on silica at room temperature affords the corresponding benzoxazoles (or benzothiazoles) in excellent yields (88-96%) under heterogeneous conditions. Benzoxazoles and benzothiazoles are formed in less than 10 min.
Photocatalytic green synthesis of benzazoles from alcohol oxidation/toluene sp3C-H activation over metal-free BCN: effect of crystallinity and N-B pair exposure
Cheng, Hongmei,Gao, Xue,Jiang, Heyan,Sun, Bin,Zang, Cuicui
, p. 7955 - 7962 (2021/12/27)
Porous borocarbonitride (P-BCN), with the characteristics of enhanced crystallinity and improved N-B pair exposure, was prepared with a simple KCl-assisted molten salt strategy. Efficient heterogeneous photocatalytic tandem synthesis of benzazoles from alcohol oxidation/toluene sp3C-H activation was achieved firstly over the metal-free P-BCN using visible light and the green oxidant O2, with only water as a by-product. Variouso-thio/hydroxy/aminoanilines and alcohols or toluenes could be converted to the corresponding 2-substituted benzothiazoles, benzoxazoles and benzimidazoles with good to excellent photocatalytic performance. The improved photocatalytic performance in comparison to bulk BCN should be due to the crystallinity-enhancement-induced improvement in charge separation and transmission. The increased N-B pair exposure promoted superoxide radical generation due to the electron-enriched N atoms, as well as improved oxidation ability due to the valence band constructed by the B 2p orbital. This work presents a green and efficient synthetic strategy towards benzazoles and other fine chemicalsviametal-free heterogeneous photocatalysis.
Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes
Liu, Yao,Li, Ji-Lin,Liu, Xu-Ge,Wu, Jia-Qiang,Huang, Zhi-Shu,Li, Qingjiang,Wang, Honggen
, p. 1891 - 1897 (2021/03/08)
Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.
ZnO-NPs catalyzed condensation of 2-aminothiophenol and aryl/alkyl nitriles: Efficient green synthesis of 2-substituted benzothiazoles
Dhawale, Kiran D.,Ingale, Ajit P.,Shinde, Sandeep V.,Thorat, Nitin M.,Patil, Limbraj R.
, p. 1588 - 1601 (2021/03/18)
The synthesis of 2-substituted benzothiazoles has been described using ZnO-nanoparticles as a catalyst. The condensation of 2-aminothiophenol and aryl/alkyl nitriles resulted in the formation of various 2-substituted benzothiazoles under solvent-free reaction conditions. The library of 2-substituted benzothiazoles has been synthesized in good to excellent yield. The reaction has shown a wide range of functional group compatibility for both varyingly substituted 2-aminothiophenols and nitriles. The protocol has many advantages such as faster reaction rate, mild reaction conditions, various functional group compatibility, excellent yield, solvent-free reaction conditions, easy recovery of materials, and excellent catalyst recyclability, among others. The various advantages of this protocol make it a more feasible, economical, and environmentally benign process.
"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.
Sulfamic acid-catalyzed conversion of o-aminothiophenol and aromatic aldehydes to 2-arylbenzothiazoles
Shi, Chunjie,Song, Renyuan,Wang, Guangrong,Yu, Xiaofeng
, p. 871 - 879 (2020/09/09)
Non-metallic, non-toxic, and cheap sulfamic acid was used as a catalyst for the synthesis of 2-arylbenzothiazole from o-aminothiophenol and aromatic aldehydes bearing electron-donating or electron-withdrawing groups. The sulfamic acid catalyst can be reus
