Microwave-assisted synthesis and transformations of sterically hindered 3-(5-tetrazolyl)pyridines
作者:Sergey M. Lukyanov、Igor V. Bliznets、Sergey V. Shorshnev、Grigory G. Aleksandrov、Aleksandr E. Stepanov、Andrei A. Vasil'ev
DOI:10.1016/j.tet.2005.11.039
日期:2006.2
Sterically hindered 2,4-disubstituted 3-(5-tetrazolyl)pyridines were synthesized from corresponding nicotinonitriles using microwave technology. 2-Methylnicotinonitriles were converted into the 2-azidomethyl-3-cyanopyridines via 2-hydroxymethyl and 2-chloromethyl derivatives. Intramolecular [3+2] cycloaddition of an heteroaromatic cyano group to side azido group was carried out to form a novel heterocyclic
使用微波技术由相应的烟腈合成了位阻2,4-二取代的3-(5-四唑基)吡啶。通过2-羟甲基和2-氯甲基衍生物将2-甲基烟腈转化为2-叠氮基甲基-3-氰基吡啶。进行杂芳族氰基至侧叠氮基的分子内[3 + 2]环加成反应,以形成含有(四唑)氮杂异吲哚单元的新型杂环系统。2-甲基烟腈和醛的缩合产生相应的2-乙烯基衍生物,然后将其转化为新型杂环系统(5,6-dihydrotetrazolo [5,1- f] -1,6-萘啶)通过四唑环与烯烃片段的分子内N-烷基化反应。将获得的3-(5-四唑基)吡啶烷基化,得到各种N-和C-苄基衍生物,并进行酰化,以高收率得到3-(1,3,4-恶二唑-2-基)吡啶。上述大多数反应是在微波辐射下进行的。