2(1H)-Pyrazinones bearing an X-(o-C6H4)-CC-R moiety (X = O or NH; R = H, Ph or TMS) at position 3 were subjected to intramolecular Diels-Alder reaction. For the ether compounds (X = O) cycloaddition-elimination occurred readily to produce either benzofuro[2,3-c]pyridin-1(2-H)-ones or benzofuro[2,3-b]pyridines. For the aniline derivatives (X = NH, R = H or TMS) thermolysis in acetic anhydride resulted
在位置3上带有X-(o -C 6 H 4)-CCR部分(X = O或NH; R = H,Ph或TMS)的2(1 H)-
吡嗪酮进行分子内Diels-Alder反应。对于
醚类化合物(X = O),很容易发生环加成消除反应,从而生成
苯并呋喃[2,3- c ]
吡啶-1(2- H)-ones或
苯并呋喃[2,3- b]
吡啶。对于
苯胺衍
生物(X = NH,R = H或TMS),在
乙酸酐中进行热分解可产生类似的β-咔啉酮和α-咔啉产物分布,但是与先前在回流四氢
萘中获得的产物分布不同。该结果由
苯胺NH-乙酰化的前体进行的环加成反应解释。然而,具有Ph作为炔属端基(X = NH,R = Ph)的
苯胺衍
生物通过发散途径反应产生N-(2-氧代
吡嗪-3-基)-2-Ph-取代的
吲哚。