1629-07-8Relevant articles and documents
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).
Method for preparing benzothiazole compound from visible light promoted N-(2-bromophenyl) thioamide
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Paragraph 0088-0090, (2021/06/22)
The invention discloses a method for preparing a benzothiazole compound from N-(2-bromophenyl) thioamide under the promotion of visible light. Specifically, under the protection of inert gas, according to the molar ratio of N-(2-bromophenyl) thioamide to inorganic base being 1: 0.5, reactants are added into a reaction container provided with a stirring device, then dimethyl sulfoxide is added, and stirring reaction is carried out for 2-24 hours at room temperature under the irradiation of visible light to obtain the benzothiazole compound. Under the condition of not adding any photosensitizer or transition metal catalyst, sodium phosphate is used as alkali, and under the irradiation of a 45W household compact fluorescent lamp, a series of intramolecular cross-coupling reactions of N-(2-bromophenyl) thioamide are realized. In addition, the benzothiazole compound can be obtained with high yield. The whole process is green, efficient and easy to operate, and the method is a good method for synthesizing the benzothiazole compound.
Preparation method of 2-substituted benzothiazole
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Paragraph 0100-0105, (2020/11/09)
The invention discloses a preparation method of 2-substituted benzothiazole, and belongs to the field of organic chemical synthesis. The preparation method of the 2-substituted benzothiazole specifically comprises the following steps: by taking an N-aryl thioamide compound as a raw material and taking graphite-phase carbon nitride (g-C3N4) prepared by urea thermal polymerization condensation as aphotocatalyst, carrying out a cyclization reaction under a mild condition to prepare the 2-substituted benzothiazole. The method has the advantages of simple operation, cheap and easily available catalyst, mild reaction conditions, wide substrate application range, no strong oxidant and no metal residue, and provides an economical, practical, green and environment-friendly new method for synthesisof 2-substituted benzothiazole widely applied to the fields of medicines, dyes, pesticides and the like.