The azide/tetrazole equilibrium: an investigation in the series of furo- and thieno[2,3-e]tetrazolo[3,2-d]pyrimidine derivatives
作者:Samvel N. Sirakanyan、Domenico Spinelli、Athina Geronikaki、Viktor G. Kartsev、Henrik A. Panosyan、Armen G. Ayvazyan、Rafael A. Tamazyan、Vincenzo Frenna、Anush A. Hovakimyan
DOI:10.1016/j.tet.2016.02.048
日期:2016.4
excellent yields, which in solution exist in equilibrium with 7(8)-azidofuro(thieno)[3,2-d]pyrimidines 3A and 4A. Compounds 3T/3A and 4T/4A represent useful substrates for investigating the azide/tetrazole equilibrium: it has been examined as a function of solvent, temperature, and their structure. We have observed that, in solution, in both 3 and 4 the equilibrium was strongly affected by the solvent used
从7(8)-氯呋喃(噻吩并)[3,2- d ]嘧啶1开始,通过与肼反应获得相应的7(8)-肼基呋喃(噻吩并)[3,2- d ]嘧啶2。通过用亚硝酸处理,化合物2以优异的产率得到了熔融的呋喃-和噻吩并[2,3- e ]四唑[1,5- c ]嘧啶3 T和4 T,它们在溶液中与7(8)平衡存在。 -azidofuro(噻吩并)[3,2- d ]嘧啶3甲和4甲。化合物3 T / 3 A和4 T / 4 A代表用于研究叠氮化物/四唑平衡的有用底物:已根据溶剂,温度及其结构进行了检查。我们已经观察到,在溶液中,在3和4中,平衡都受到所用溶剂的强烈影响。相比之下,X射线分析表明噻吩并[2,3- e ] tetrazolo [1,5- c ]嘧啶和呋喃[2,3- e ] tetrazolo [1,5- c固态的嘧啶仅以四唑互变异构形式存在。因此,已经在不同溶剂中计算出了平衡常数和相关的热力学参数:最终观察到一系列(七个)ΔG