Synthesis of Coumarin Substituted Triazolothiadiazine Derivatives<i>via</i>Ring Transformation Reaction
作者:Venkata Sreenivasa Rao Chunduru、Vedula Rajeswar Rao
DOI:10.1002/jhet.958
日期:2013.1
the synthesis of 3‐(3‐aryl‐7H‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazin‐6‐yl)‐2H‐chromen‐2‐ones has been described. Reaction of 3‐(2‐bromoacetyl)coumarins (1) with 5‐aryl‐1,3,4‐oxadiazole‐2‐thiol (2) gave ketones (4a–h). The in situ formed ketones (4a–h) were reacted with hydrazine hydrate to give 3‐(3‐aryl‐7H‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazin‐6‐yl)‐2H‐chromen‐2‐ones (3a–h) and not 5 or 6. The
为3-合成了一种新的环变换反应(3-芳基- 7H - [1,2,4]三唑并[3,4- b ] [1,3,4]噻二嗪-6-基)-2 ħ - chromen-2-one已被描述。3-(2-溴乙酰基)香豆素(1)与5-芳基-1,3,4-恶二唑-2-硫醇(2)的反应生成酮(4a–h)。将原位形成的酮(4a–h)与水合肼反应,生成3‐(3‐芳基‐7H‐ [1,2,4]三唑并[3,4‐ b ] [1,3,4]噻二嗪‐ 6‐yl)‐2 H ‐chromen‐2‐1(3a–h),而不是5或6。化合物(3a–h)也可通过使3-(2-溴乙酰基)香豆素(1)与5-芳基-1,3,4-恶二唑-2-硫醇(2)在无水乙醇中反应制得相应的3-(2- (5-芳基-1,3,4-恶二唑-2-基硫基)乙酰基)-2 H-铬-2-基(4a–h)。这些与水合肼在乙酸中反应时得到相应的3-(3-芳基-7H- [1,2,4]三唑[3,4-