22868-31-1Relevant academic research and scientific papers
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
Synthesis, characterization, crystal structures, and anticancer activity of some new 2,3-dihydro-1,5-benzoxazepines
Odame, Felix,Schoeman, Recardia,Krause, Jason,Hosten, Eric C.,Tshentu, Zenixole R.,Frost, Carminita
supporting information, p. 987 - 1004 (2021/02/16)
Various benzoxazepine derivatives have been synthesized and characterized using IR, NMR, GC–MS, and microanalysis. The single-crystal X-ray structures of 2,2-dimethyl-4-[(E)-2-(4-methylphenyl)ethenyl]-2,3-dihydro-1,5-benzoxazepine (RS01), 4-[(E)-2-(2-chlo
α-Keto Acids as Triggers and Partners for the Synthesis of Quinazolinones, Quinoxalinones, Benzooxazinones, and Benzothiazoles in Water
Huang, Jian,Chen, Wei,Liang, Jiazhi,Yang, Qin,Fan, Yan,Chen, Mu-Wang,Peng, Yiyuan
, p. 14866 - 14882 (2021/10/25)
A general and efficient method for the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil. More importantly, these reactions can be conducted on a mass scale, and the products can be easily purified through filtration and washing with ethanol (or crystallized).
KOtBu-Promoted Halogen-Bond-Assisted Intramolecular C-S Cross-Coupling of o-Iodothioanilides for the Synthesis of 2-Substituted Benzothiazoles
Nandy, Anuradha,Sekar, Govindasamy
, p. 15825 - 15834 (2021/11/01)
An efficacious and mild KOtBu-promoted intramolecular C-S cross-coupling of ortho-iodothioanilides in conjunction with a catalytic quantity of phenanthroline as an additive has been described for the convenient synthesis of 2-substituted benzothiazoles. The methodology is suitable for attaining a wide variety of 2-alkyl- and 2-aryl-substituted benzothiazoles. Single-crystal XRD, DFT calculations, NMR, and UV studies suggest that halogen bonds between the units of ortho-iodothioanilides may assist in the electron transfer process.
Sulfur-Promoted Redox Cyclization of 2,2′-Dinitrodiphenyl Disulfides and Benzylamines
Teramoto, Masahiro,Imoto, Mitsutaka,Takeda, Motonori,Mizuno, Takumi,Nomoto, Akihiro,Ogawa, Akiya
, p. 2485 - 2493 (2021/04/15)
This study aims to develop green and sustainable advanced synthetic methods based on redox cyclization. Elemental sulfur is shown to promote the efficient synthesis of 2-substituted benzothiazoles from 2,2′-dinitrodiphenyl disulfides and benzylamines via redox cyclization in the absence of transition-metal catalysts and solvents. The 2-substituted benzothiazoles are obtained in good to excellent yields. This synthetic methodology is highly atom-economical and does not require any external oxidizing and/or reducing agents.
Improved, gram-scale synthesis of sildenafil in water using arylacetic acid as the acyl source in the pyrazolo[4,3-d]pyrimidin-7-one ring formation
Laha, Joydev K.,Gulati, Upma,Saima,Gupta, Anjali,Indurthi, Harish Kumar
supporting information, p. 2643 - 2648 (2021/02/16)
An improved, gram-scale synthesis of the blockbuster drug sildenafil, used for the treatment of male erectile dysfunction, has been developed. Unlike the previous literature, the current method demonstrates the use of arylacetic acid as an acyl source, a cheap oxidant K2S2O8, and water as the reaction medium in the key step of pyrrazolo[4,3-d]pyrimidin-7-one ring formation. As well as being a green and benign approach, the current method reduces the cost by half compared to our previous strategy. In addition, the general relevance of the method has been demonstrated in the synthesis of a variety of quinazolinone and benzothiazole derivatives with excellent functional group tolerance.
Oxidant/Solvent-Controlled I2-Catalyzed Domino Annulation for Selective Synthesis of 2-Aroylbenzothiazoles and 2-Arylbenzothiazoles under Metal-Free Conditions
Ma, Renchao,Ding, Yuxin,Chen, Rener,Wang, Zhiming,Wang, Lei,Ma, Yongmin
, p. 310 - 321 (2021/01/09)
A simple and practical domino protocol for the selective synthesis of 2-aroylbenzothiazoles and 2-aryl benzothiazoles catalyzed by I2 is developed under metal-free conditions. The reaction outcomes are exclusively controlled by the reaction oxidant/medium. With DMSO employed as both the solvent and the oxidant, an oxidation of aromatic methyl ketones takes precedence over the condensation with 2-aminobenzenethiols. On the other hand, when the reaction was carried out in PhNO2 or in 1,4-dioxane containing PhNO2, the condensation of aromatic methyl ketones with 2-aminobenzenethiols has priority to form imines which is followed by an oxidation of the methyl group from ketones to afford 2-arylbenzothiazoles as a sole product. The PhNO2/I2 co-catalytic system is proposed first time.
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.
Photoinduced Heterogeneous C?H Arylation by a Reusable Hybrid Copper Catalyst
Choi, Isaac,Müller, Valentin,Lole, Gaurav,K?hler, Robert,Karius, Volker,Vi?l, Wolfgang,Jooss, Christian,Ackermann, Lutz
supporting information, p. 3509 - 3514 (2020/03/03)
Heterogeneous copper catalysis enabled photoinduced C?H arylations under exceedingly mild conditions at room temperature. The versatile hybrid copper catalyst provided step-economical access to arylated heteroarenes, terpenes and alkaloid natural products with various aryl halides. The hybrid copper catalyst could be reused without significant loss of catalytic efficacy. Detailed studies in terms of TEM, HRTEM and XPS analysis of the hybrid copper catalyst, among others, supported its outstanding stability and reusability.
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
