92161-46-1Relevant articles and documents
Ionic-Liquid-Catalyzed Synthesis of Imines, Benzimidazoles, Benzothiazoles, Quinoxalines and Quinolines through C?N, C?S, and C?C Bond Formation
Adimurthy, Subbarayappa,Badhani, Gaurav,Joshi, Abhisek
, p. 6705 - 6716 (2021/12/31)
We report the tetramethyl ammonium hydroxide catalyzed oxidative coupling of amines and alcohols for the synthesis of imines under metal-free conditions by utilizing oxygen from air as the terminal oxidant. Under the same conditions, with ortho-phenylene diamines and 2-aminobenzenethiols the corresponding benzimidazoles and benzothiazoles were obtained. Quinoxalines were obtained from ortho-phenylene diamines and 1-phenylethane-1,2-diol, the conditions were then extended to the synthesis of quinoline building blocks by reaction of 2-amino benzyl alcohols either with 1-phenylethan-1-ol or acetophenone derivatives. The formation of C?N, C?S and C?C bonds was achieved under metal-free conditions. A broad range of amines (aromatic, aliphatic, cyclic and heteroaromatic) as well as benzylic alcohols including heteroaryl alcohols reacted smoothly and provided the desired products. The mild reaction conditions, commercially available catalyst, metal-free, good functional-group tolerance, broad range of products (imines, benzimidazoles, benzothiazoles, quinoxalines and quinolines) and applicability at gram scale reactions are the advantages of the present strategy.
Urea nitrate–catalyzed C-N and C-S bond formation: A mechanochemical approach for 5-chloro-2-arylbenzo[d]thiazole derivatives
Sethiya, Ayushi,Sahiba, Nusrat,Soni, Jay,Agarwal, Shikha
, p. 873 - 881 (2021/02/01)
A series of substituted 5-chloro-2-arylbenzo[d]thiazoles were synthesized using 4-chloro-2-aminothiophenol and aromatic aldehydes in the presence of urea nitrate as a catalyst using the mechanochemical grindstone technique. This protocol was effectively carried out under metal-free conditions at room temperature, and the desired products were obtained in high to excellent yields in short reaction time (30–60 s). The structure of all the synthesized derivatives was confirmed by spectral characterization. The designed protocol has several benefits like eco-friendly, solvent-free, high yields, easy workup, and recyclability of catalyst. The catalyst was reusable at least four times without significant loss of activity. The good functional group tolerance with a series of derivatives has been demonstrated.
Synthesis of Benzothiazoles via Photooxidative Decarboxylation of α-Keto Acids
Monga, Aparna,Bagchi, Sourav,Soni, Raj Kumar,Sharma, Anuj
supporting information, p. 2232 - 2237 (2020/03/04)
Herein, synthesis of benzothiazoles via decarboxylative cross-coupling between α-keto acids and 2-aminothiophenols under blue LED irradiation without using any photocatalyst or metal at room temperature is described. The formation of benzothiazole is driven by the EDA (electron donor-acceptor) complex formed between α-keto acid and 2-aminothiophenol. This methodology gives easy access to 2-substituted and -unsubstituted benzothiazoles in moderate to good yields. α-Keto acids and 2-aminothiophenols bearing different functional groups were easily transformed under the given conditions. (Figure presented.).
