Syntheses and evaluation of pyridazine and pyrimidine Containing bioisosteres of (±)-Pyrido[3.4-b]homotropane and Pyrido-[3.4-b]tropane as novel nAChR ligands
作者:Daniela Gündisch、Thomas Kämpchen、Simone Schwarz、Gunther Seitz、Johanna Siegl、Thomas Wegge
DOI:10.1016/s0968-0896(01)00258-9
日期:2002.1
(+)-anatoxin-a (1), replacement of the pyridine by the bioisosteric pyridazine resulted in 30-fold lower affinity at the (alpha4)2(beta2)3 subtype. The annulated diazinotropanes 6-8, ligands with ferruginine-like structures more or less retained the affinity of (-)-norferruginine (3) except of compound 7. Remarkably, all of the novel ligands are devoid of affinity at the alpha7* subtype.
用哒嗪和嘧啶核生物置换(+/-)-吡啶并[3.4-b]高托烷(PHT)和吡啶[3.4-b]托烷中的吡啶药效成分导致迄今未知的nAChR配体,如5-8。逆型Diels-Alder反应构成了通往哒嗪或嘧啶环化的生物等位基因新路线的关键步骤。来自“手性库”的对映体纯(+)-2-托宁酮(11)被转化为扩环的甲硅烷基烯醇醚12和烯胺15。两者均被证明是逆型[4 + 2与1,2,4,5-四嗪13和16a,b或与1,3,5-三嗪19的环加成反应以提供对映纯的目标化合物5-7。以相同的方式从3-对pan酮21获得外消旋嘧啶环化的物质8。测试了新的配体在体外对(alpha4)2(beta2)3和alpha7 * nAChR亚型的亲和力。与众所周知对大鼠脑中激动剂结合位点表现出亲和力的PHT(约)(+)-毒素(a)相比,生物等位哒嗪取代吡啶导致的亲和力降低30倍。 (alpha4)2(beta2)3亚型。除了