Feng Enguang, Huang He, Zhou Yu, Ye Deju, Jiang Hualiang, Liu Hong
The Center for Drug Discovery and Design, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, PR China.
J Comb Chem. 2010 Jul 12;12(4):422-9. doi: 10.1021/cc9001839.
An efficient, economical, and convenient method was developed for the preparation of 2-substituted (N, O, C) benzothiazoles from N'-substituted-N-(2-halophenyl)thioureas, O'-substituted-N-(2-halophenyl) carbamothioates, or N-(2-halophenyl) thioamides via a base-promoted cyclization in dioxane without any transition metal. A one-pot variant combining the synthesis of the thiourea and the cyclization was also demonstrated. High yields were obtained, and a variety of functional groups were tolerated under these conditions. Transition-metal-free, mild reactive conditions, wide application scope, and shorter reaction times make this method superior to the reported methods for the synthesis of 2-substituted benzothiazoles and suitable for combinatorial format.
开发了一种高效、经济且便捷的方法，用于从N'-取代-N-(2-卤代苯基)硫脲、O'-取代-N-(2-卤代苯基)氨基硫代甲酸酯或N-(2-卤代苯基)硫代酰胺，通过在二氧六环中碱促进的环化反应制备2-取代（N、O、C）苯并噻唑，无需任何过渡金属。还展示了一种将硫脲合成与环化反应相结合的一锅法变体。该方法产率高，在这些条件下能耐受多种官能团。无过渡金属、温和的反应条件、广泛的应用范围以及较短的反应时间，使得该方法优于已报道的合成2-取代苯并噻唑的方法，适用于组合形式。
