One-Pot Synthesis of<i>N</i>-(Imidazo[1,2-<i>a</i>]pyridin-3-yl)- and<i>N</i>-(Imidazo[2,1-<i>b</i>][1,3]thiazol-5-yl)sulfonamides
作者:Igor B. Rozentsveig、Valery Y. Serykh、Gulnur N. Chernysheva、Kirill A. Chernyshev、Evgeniy V. Kondrashov、Evgeny V. Tretyakov、Galina V. Romanenko
DOI:10.1002/ejoc.201201006
日期:2013.1
2-dichloro-2-phenyl-1-(heterylamino)ethyl]sulfonamides, in good yields. The latter are easily cyclized to (imidazo[1,2-a]pyridin-3-yl)sulfonamides and (imidazo[2,1-b]thiazol-5-yl)sulfonamides in the presence of alkali, whereas the expected isomeric (imidazo[1,2-a]pyridin-2-yl)sulfonamides and (imidazo[2,1-b]thiazol-6-yl)sulfonamides are not formed. A one-pot two-stage method for the synthesis of target heterocyclic
2-氨基吡啶或2-氨基噻唑与N-(2,2-二氯-2-苯基亚乙基)芳磺酰胺反应得到相应的偶氮甲碱基团亲核加成产物,N-[2,2-二氯-2-苯基- 1-(杂氨基)乙基]磺酰胺,收率良好。后者在碱存在下很容易环化为(咪唑并[1,2-a]吡啶-3-基)磺酰胺和(咪唑并[2,1-b]噻唑-5-基)磺酰胺,而预期的异构体(不形成咪唑并[1,2-a]吡啶-2-基)磺酰胺和(咪唑并[2,1-b]噻唑-6-基)磺酰胺。开发了一种无需分离中间体即可合成目标杂环化合物的一锅两步法。已经提出了形成环状杂环衍生物的初步机制。