348-45-8Relevant academic research and scientific papers
Switchable and Scalable Heteroarylation of Primary Amines with 2-Chlorobenzothiazoles under Transition-Metal-Free and Solvent-Free Conditions
Cheng, Hua,Zhu, Yan-Qiu,Liu, Peng-Fei,Yang, Kai-Qiang,Yan, Jin,Sang, Wei,Tang, Xiao-Sheng,Zhang, Rui,Chen, Cheng
, p. 10288 - 10302 (2021/08/16)
2-Aminobenzothiazoles comprise a valuable structural motif, which prevails in versatile natural products and biologically active compounds. Herein, a switchable and scalable C-N coupling protocol was developed for the synthesis of these compounds from 2-chlorobenzothiazoles and primary amines. Gratifyingly, this protocol was achieved under transition-metal-free and solvent-free conditions. Moreover, introducing an appropriate amount of NaH completely switched the selectivity from mono- toward di-heteroarylation, and further investigations provided a rationale for this new finding. Furthermore, gram-scale synthesis of representative products 3a and 4a was realized by applying operationally simple and glovebox-free procedures, which revealed the practical usefulness of this work. Finally, evaluation of the quantitative green metrics provided evidence that our protocol was superior over the literature ones in terms of green chemistry and sustainability.
Environment-friendly and efficient synthesis of 2-aminobenzo-xazoles and 2-aminobenzothiazoles catalyzed by: Vitreoscilla hemoglobin incorporating a cobalt porphyrin cofactor
Li, Fengxi,Li, Zhengqiang,Su, Jiali,Wang, Chunyu,Wang, Ciduo,Wang, Lei,Xu, Yaning,Zhao, Nan
, p. 8047 - 8052 (2021/11/01)
In this study, an environment-friendly and efficient artificial Vitreoscilla hemoglobin (VHb) for the synthesis of 2-aminobenzoxazoles and 2-aminobenzothiazoles has been reported. We demonstrate an expression-based porphyrin substitution strategy to produce VHb containing cobalt porphyrin instead of native hemin, which can catalyze the oxidative cyclization of corresponding 2-aminobenzoxazoles and 2-aminobenthiazoles with up to 97% yield and 4850 catalytic turnovers in water under aerobic conditions. Hence, we provide a green and mild method for the synthesis of 2-aminobenzoxazoles and 2-aminobenzothiazoles. In addition, we indicate the value of porphyrin ligand substitution as a strategy to tune and enhance the catalytic properties of hemoproteins in non-natural reactions.
A practical synthesis of 2-aminobenzothiazoles via copper(I)-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates in ionic liquids
Chen, Ling,Huang, Bin,Nie, Quan,Cai, Mingzhong
, p. 446 - 450 (2016/05/19)
A copper(I)-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates was achieved in hydrophobic [bmim][PF6] ionic liquid under mild conditions, generating a variety of 2-aminobenzothiazoles in good to excellent yields. The tandem reaction that was carried out in [bmim][PF6] has some obvious advantages such as accelerated reaction rate and increased yield as compared with the reaction run in volatile solvents such as toluene. Furthermore, the CuI/1,10-phenanthroline catalytic system can be reused up to eight times without loss of activity and efficiency.
A Synthesis of Benzothiazoles and Indoles by Direct C(sp2)-I Activation Catalyzed by Copper(II) on Silica-Coated Magnetite Nanoparticles
Moghadam, Faeze Kiani,Jarrah, Najmeh,Mashayekh-Salehi, Ali,Ghanbaripour, Rashid
, p. 1665 - 1668 (2016/07/06)
N-Substituted 2-amino-1,3-benzothiazoles and 2,3-disubstituted indoles were prepared by C-S and C-C cross-coupling reactions of 2-iodoanilines with isothiocyanates or 1,3-dicarbonyl compounds, respectively, in the presence of magnetic nanoparticles functionalized with a copper(II)-Schiff base complex as an efficient and reusable catalyst.
Oxidative coupling of formamides with β-dicarbonyl compounds and the synthesis of 2-aminobenzothiazole using Cu(II)-functionalized Fe3O4 nanoparticles This article is dedicated to memory of Mostafa Chamran.
Azizi, Kobra,Karimi, Meghdad,Heydari, Akbar
, p. 812 - 816 (2015/02/19)
The Fe3O4@EDTA-Cu(II) nanoparticles catalyzed oxidative coupling of formamides with β-dicarbonyl compounds is developed using tert-butyl hydroperoxide as an oxidant. In general, the enol carbamates are synthesized in excellent yields (up to 92%) under the optimized reaction conditions. Fe3O4@EDTA-Cu(II) has the advantage of being magnetically recoverable. Also, we have established a highly efficient Fe3O4@EDTA-Cu(II)-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates for the synthesis of 2-aminobenzothiazoles.
Straightforward synthesis of 2-anilinobenzoxazoles and -benzothiazoles via mechanochemical ball-milling-promoted one-pot reactions
Zhang, Ze,Wang, Fang-Jian,Wu, Hao-Hao,Tan, Ya-Jun
supporting information, p. 440 - 441 (2015/05/27)
Under mechanochemical ball-milling and solvent-free conditions, a series of 2-anilinobenzoxazoles and -thiazoles were synthesized directly from the one-pot reaction of anilines, CS2, and 2-aminophenol and -thiophenol. This protocol exhibits the
Dithiocarbamate promoted practical synthesis of N-Aryl-2-aminobenzazoles: Synthesis of novel Aurora-A kinase inhibitor
Katari, Naresh Kumar,Venkatanarayana,Srinivas, Kummari
, p. 447 - 453 (2015/05/20)
Various N-aryl-2-aminobenzoxazoles and N-aryl-2-aminobenzothiazoles were synthesized from o-aminophenol and o-aminothiophenol, respectively, mediated by dithiocarbamate in one step. The salient features of this method include mild reaction condition, high
Ligand- and solvent-free synthesis of 2-aminobenzothiazoles by copper-catalyzed tandem reaction of 2-haloanilines with isothiocyanates
Yao, Ruiya,Liu, Haiyi,Wu, Yichao,Cai, Mingzhong
, p. 109 - 113 (2013/03/13)
We report an environmentally friendly, efficient and practical method for the synthesis of 2-aminobenzothiazoles by a copper(II)-catalyzed tandem reaction of 2-haloanilines with isothiocyanates under ligand- and solvent-free conditions in air. The developed methodology conforms to the principles of 'green chemistry' and addresses the shortage of such methods for the synthesis of 2-aminobenzothiazoles. The reaction is quite general and generates a variety of 2-aminobenzothiazoles in good to excellent yields. Copyright
A new and efficient synthesis of 2-aminobenzothiazoles derivatives from o-nitroaniline
Mirza, Behrooz,Mirzazadeh, Roghieh,Zeeb, Mohsen
, p. 778 - 779 (2014/01/23)
A novel sy nthesis of 2-aminobenzothia zoles from a transition-met al-free reaction between aryl isothioc yanates and o-nitroaniline in the presence of K2CO3 is reported. The newly developed method is an efficient and cost-effective approach to synthesise 2-aminobenzothiazoles.
An "on-water" exploration of CuO nanoparticle catalysed synthesis of 2-aminobenzothiazoles
Rout, Saroj Kumar,Guin, Srimanta,Nath, Jayashree,Patel, Bhisma K.
, p. 2491 - 2498 (2013/02/21)
An "on-water" one-pot process has been engineered for the preparation of 2-aminobenzothiazole from ortho-halo (-F, -Cl, -Br and -I) substituted unsymmetrical thioureas. For ortho -I and -Br substrates the reactions afford 2-aminobenzothiazoles under metal free condition promoted by base. However, the relatively inert ortho -Cl and -F substrates undergo intramolecular arylthiolation only in the presence of CuO nanoparticles yielding 2-aminobenzothiazoles. This methodology provides easy access to aminobenzothiazoles utilising even the ortho -Cl and -F substrates. The catalyst is recyclable several times without loss of substantial activity. Other remarkable features include the wide range of functional group tolerance, absence of chromatographic purification (for ortho -I and -Br substrates) and providing moderate to excellent yield of the products under mild conditions, thus rendering the methodology as a highly eco-friendly alternative to the existing methods.
