16763-01-2Relevant academic research and scientific papers
BENZOTHIAZOLE COMPOUNDS AND USES THEREOF
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Page/Page column 72-73, (2021/12/29)
The present invention features compounds useful in the treatment of neurological disorders. The compounds of the invention, alone or in combination with other pharmaceutically active agents, can be used for treating or preventing neurological disorders.
Synthetic method for N-alkyl(benzo)thiazole
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Paragraph 0020, (2019/10/01)
The invention provides a synthetic method for N-alkyl(benzo)thiazole. The synthetic method comprises the following steps: putting 0.4-0.8 mmol of a carbonyl compound, 0.4-0.8 mmol of p-toluenesulfonylhydrazide and 4-10 mL of a solvent in a flask and carrying out a reaction at 30 DEG C to 80 DEG C for 1 to 3 h; adding 0.4 mmol of 2-aminothiazole, 0.4-0.8 mmol of metal copper salt and 0.4-1.2 mmolof an alkali substance into the above reaction system, carrying out heating to 100 DEG C to 150 DEG C, and continuing the reaction for 2 h to 5 h; terminating the reaction to obtain a reaction productA; and subjecting the product A to purification and impurity separation so as to obtain pure N-alkyl(benzo)thiazole. According to the invention, the intermediate sulfonyl hydrazone is prepared from the carbonyl compound and sulfonyl hydrazide, and reacts with a 2-aminothiazole substance in the presence of a catalyst and under alkali conditions to obtain N-alkyl(benzo)thiazole. The synthetic method of the invention has the advantages of simple operation, low cost, high product yield and wide application range of a substrate. At the same time, the established method can also realize the synthesis of the anti-inflammatory drug fanetizole, and thus has high practical value.
Copper-catalyzed one-pot coupling reactions of aldehydes (ketones), tosylhydrazide and 2-amino(benzo)thiazoles: An efficient strategy for the synthesis of N-alkylated (benzo)thiazoles
Xie, Zengyang,Chen, Ruijiao,Ma, Mingfang,Kong, Lingdong,Liu, Jun,Wang, Cunde
, (2019/08/16)
An efficient and practical C–N bond formation methodology for the synthesis of N-alkylated (benzo)thiazoles was developed, via the copper-catalyzed one-pot two-step reactions of 2-amino(benzo)thiazoles and aldehydes (ketones) with tosylhydrazide. This cross-coupling reaction proceeded smoothly and tolerated a broad range of functional groups (46 examples). A variety of functionalized N-alkylated (benzo)thiazoles were obtained in moderate to high yields. Notably, gram-scale synthesis of fanetizole (anti-inflammatory drug) was also realized through this protocol.
Phosphine-Free Well-Defined Mn(I) Complex-Catalyzed Synthesis of Amine, Imine, and 2,3-Dihydro-1 H-perimidine via Hydrogen Autotransfer or Acceptorless Dehydrogenative Coupling of Amine and Alcohol
Das, Kalicharan,Mondal, Avijit,Pal, Debjyoti,Srivastava, Hemant Kumar,Srimani, Dipankar
supporting information, p. 1815 - 1825 (2019/04/30)
The application of nontoxic, earth-abundant transition metals in place of costly noble metals is a paramount goal in catalysis and is especially interesting if the air- and moisture-stable ligand scaffold is used. Herein, we report the synthesis of amines/imines directly from alcohol and amines via hydrogen autotransfer or acceptorless dehydrogenation catalyzed by well-defined phosphine-free Mn complexes. Both imines and amines can be obtained from the same set of alcohols and amines using the same catalyst, only by tuning the reaction conditions. The amount and nature of the base are found to be a highly important aspect for the observed selectivity. Both the primary and secondary amines have been employed as substrates for the N-alkylation reaction. As a highlight, we showed the chemoselective synthesis of resveratrol derivatives. Furthermore, the Mn-catalyzed dehydrogenative synthesis of structurally important 2,3-dihydro-1H-perimidines has also been demonstrated. Density functional theory calculations were also carried out to model the reaction path and to calculate the reaction profile.
Metal-Free Synthesis of 2-Aminobenzothiazoles via Iodine-Catalyzed and Oxygen-Promoted Cascade Reactions of Isothiocyanatobenzenes with Amines
Xu, Yuanshuang,Li, Bin,Zhang, Xinying,Fan, Xuesen
, p. 9637 - 9646 (2017/09/23)
In this paper, a highly efficient and sustainable synthesis of 2-aminobenzothiazoles through the cascade reactions of isothiocyanatobenzenes with primary or secondary amines by using iodine as a catalyst and oxygen as an oxidant is presented. Mechanistically, the formation of the title compounds involves the in situ formation of the required benzothiourea intermediate followed by its intramolecular cross dehydrogenative coupling of a C(sp2)-H bond and a S-H bond. To our knowledge, this should be the first example in which 2-aminobenzothiazoles are efficiently prepared from simple and cheap isothiocyanates and amines under metal-free conditions by using iodine as a catalyst and molecular oxygen as an oxidant with water as the byproduct. Compared with literature protocols, this method eliminates the use of ortho-halo-substituted precursors, expensive transition-metal catalysts, and hazardous oxidants.
Synthesis method of 2-aminobenzothiazole compounds
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Paragraph 0085; 0086; 0087, (2017/11/16)
The invention discloses a preparation method of 2-aminobenzothiazole compounds. The 2-aminobenzothiazole compounds is prepared from the following steps of dissolving phenyl/naphthalene isothiocyanateand primary amine into a solvent, adding a catalyst iodine and an oxidant, carrying out one-pot multi-step tandem reaction to prepare the 2-aminobenzothiazole compounds under the temperature of 80 to 150 DEG C. The synthesis method has the advantages that raw materials are cheap and easily available, the reaction condition is mild, the substrate application range is broad, atom economy is high, requirements of green chemical are met, and a novel method which is economical and practical and green and environmentally friendly is provided for synthesis of the 2-aminobenzothiazole compounds.
Structure-dependent tautomerization induced catalyst-free autocatalyzed N-alkylation of heteroaryl amines with alcohols
Li, Shuangyan,Li, Xiaohui,Li, Qiang,Yuan, Qiaochao,Shi, Xinkang,Xu, Qing
supporting information, p. 3260 - 3265 (2015/06/25)
Catalyst-free autocatalyzed dehydrative N-alkylation reactions of 2-aminobenzothiazoles, 2-aminopyrimidines, and 2-aminopyrazine with primary and secondary alcohols have been achieved for efficient, practical, and green synthesis of the versatile heteroaryl amine derivatives. These reactions were interestingly induced by structure-dependent tautomeric equilibria of the heteroaryl amines via MPV-O transfer hydrogenation of the imino tautomers by alcohols to give aldehydes as the key initiating step.
Regioselective N-alkylation of 2-aminobenzothiazoles with benzylic alcohols
Li, Feng,Shan, Haixia,Kang, Qikai,Chen, Lin
supporting information; experimental part, p. 5058 - 5060 (2011/06/09)
The preparation of 2-(N-alkylamino)benzothiazoles via regioselecive N-alkylation of 2-aminobenzothiazoles has been accomplished by using benzylic alcohols as alkylating agents.
Use of molecular oxygen as a reoxidant in the synthesis of 2-substituted benzothiazoles via palladium-catalyzed C-H functionalization/intramolecular C-S bond formation
Inamoto, Kiyofumi,Hasegawa, Chisa,Kawasaki, Junpei,Hiroya, Kou,Doi, Takayuki
experimental part, p. 2643 - 2655 (2010/12/25)
Molecular oxygen (O2) was successfully employed as a reoxidant in cyclizations of thiobenzanilides 1a-s through a palladium-catalyzed C-H functionalization/intramolecular C-S bond formation process, leading to an efficient, green method for the synthesis of 2-arylbenzothiazoles 2a-s. Addition of cesium fluoride (CsF) greatly enhanced the reactions, which produced variously substituted 2-arylbenzothiazoles with good functional group tolerance. Thioureas 4a-j were also found to be suitable substrates for the cyclization process using a palladium/O2 catalyst system, thus generating 2-aminobenzothiazoles 5a-j. One-pot syntheses of 2-aminobenzothiazoles 5a-j from aryl isothiocyanates 6 and amines 7 were also successful.
