types of pyrido-fused tris-heterocycles (1a,b and 2a,b) have been prepared from 3-aminopyridine in five/six steps. A synthetic strategy for the preparation of the novel pyrido[3,4-b]thieno[2,3- and 3,2-d]pyrroles (1a,b) and pyrido[4,3-e]thieno[2,3- and 3,2-c]pyridazines (2a,b) has been studied. The Suzuki cross coupling of the appropriate 2- and 3-thienoboronic acids (3,4) and 4-bromo-3-pyridylpivaloylamide
                                    由三
氨基吡啶经五,六个步骤制备了两种新型的
吡啶基稠合的三杂环(1a,b和2a,b)。一种合成新型
吡啶并[3,4- b ]
噻吩并[2,3-和3,2- d ]
吡咯(1a,b)和
吡啶并[4,3- e ]
噻吩并[2,3]的合成策略-和3,2- c ]
哒嗪(2a,b)已被研究。合适的2-和3- thienoboronic酸(的铃木交叉偶联3,4)和4-
溴-3- pyridylpivaloylamide(9),得到二芳基偶联产物(10,11)以高产率(85%)。
水解的(2-
噻吩基)-偶联产物(12)重氮化和
叠氮化物取代,得到3-
叠氮基-4-(2-
噻吩基)
吡啶中间体(72%,14)。通过交换先前的反应顺序来制备3-
叠氮基-4-(3-
噻吩基)
吡啶(15)。所需的β咔啉
噻吩类似物(1A,b)通过
叠氮基前体(热分解经由氮烯得到的14,15)。通过优化分子内重氮偶联的条件,可以得到相应的
哒嗪产物(72–83%,2a,b)。