Synthesis of nitrogen-containing heterocycles.<b>8</b>. Preparation and ring-opening of spiro[cycloalkane-[1′,2′,4′]triazolo[1′,5′-<i>c</i>]pyrimidine] derivatives
作者:Yoshiko Miyamoto、Chiji Yamazaki
DOI:10.1002/jhet.5570340326
日期:1997.5
Diaminomethylene- and aminomethylthiomethylenehydrazones [2] of cyclic ketones 1–8 readily reacted with ethoxymethylenemalononitrile to give spiro[cycloalkane-1,2′-[1,2′,4′]triazolo[1,5′-c]pyrimidine-8′-carbonitrile] derivatives 12–19 through the electrocyclic reaction of the initially formed condensation products 26 in moderate to high yields. The spiro[cyclopentanetriazolopyrimidine] derivatives
环状酮1-8的二氨基亚甲基和氨基甲基硫代甲基hydr [2]容易与乙氧基亚甲基丙二腈反应生成螺[环烷-1,2'-[1,2',4']三唑并[1,5' - c ]嘧啶-8' -碳腈]衍生物12-19通过最初形成的缩合产物26的电环反应以中等至高收率形成。螺[环戊烷三唑并嘧啶]衍生物在溶液中加热后在环烷烃部分开环,得到2-烷基-5-取代-[1,2,4]三唑并[1,5 - c ]嘧啶-8'-腈20 –23。当将烷基取代基引入到环戊烷环中时,螺环化合物的裂解优先发生在螺环碳和更支化的碳环之间的环戊烷部分。与此相反,环己烷环的特别螺5-氨基三唑并嘧啶,17和18强烈抵制到在类似条件下开环,但那些5- methylthiotriazolopyrimidines 14在热乙醇中长时间加热后放弃了裂解的17%。2-叔丁基-5-甲硫基-2,3-二氢[1,2,4]三唑[1,5 - c ]嘧啶-8-腈25 [R 3