Studies on organosulfur compounds. XI. Selective cyclization to benzothiazole by the reaction between quinaldine and meta-substituted anilines (or nitro compounds) under the modified Willgerodt-Kindler reaction.
摘要:
为了更详细地阐明硫代苯胺在改良的 Willgerodt-Kindler 反应条件下生成苯并噻唑的环化机理,在硫存在的情况下,将喹哪啶(I)与元取代苯胺(II)或元取代硝基苯(III)一起加热。此外,为了通过这些过程研究溶剂的影响,还使用了二甲基甲酰胺(DMF)。虽然这些反应的产率不同,但都得到了类似的硫代苯胺和两种可能的苯并噻唑中的一种。通过独立合成,证明后者具有 5-取代的 2-(2-喹啉基)苯并噻唑(V)的结构。另一方面,通过改进的雅各布森反应,硫代苯胺(IV)氧化环化得到了预期的两种异构体苯并噻唑(V 和 VI)。此外,还发现由 I 或 2-甲基吡啶得到的硫代苯胺与相应的 II 在 DMF 中于 160-170° 硫存在下发生反应,分别得到选择性环化产物。
Functionalization of Primary C–H Bonds in Picolines toward Pyridylthioamides
作者:Tuan H Ho、Ha H K Le、Tuong A To、Tung T Nguyen、Nam T S Phan
DOI:10.1246/bcsj.20200004
日期:2020.6.15
We report a method for coupling of nitroarenes, 2- or 4-methylazaarenes, and elemental sulfur to afford (2-pyridyl)aryl thioamides. Good tolerance of functionalities was observed, including primary...
Oxidative Cyclization of Thiobenzanilides to Benzothiazoles Using <i>N</i>-Benzyl-DABCO Tribromide under Mild Conditions
作者:Firouz Matloubi Moghaddam、Hassan Zali Boeini
DOI:10.1055/s-2005-869841
日期:——
N-benzyl-DABCO tribromide, a stable, crystalline organic ammonium tribromide (OATB), have been used as an alternative electrophilic bromine source for the efficient oxidative cyclization of thiobenzanilides to the corresponding benzothiazoles under mild conditions.