Preparation of New Nitrogen-Bridged Heterocycles. 29. Reinvestigation on the Dehydrogenation Reaction of 5,5a-Dihydropyrido[2,1-<i>c</i>]thieno[3,2-<i>e</i>][1,4]thiazine Derivatives
作者:Akikazu Kakehi、Suketaka Ito、Jun-ichi Hakui、Hiroaki Fukazawa
DOI:10.1246/bcsj.65.1244
日期:1992.5
rearranged thieno[2,3-b]indolizines, as described previously by us, but were ordinary dehydrogenated compounds, pyrido[2,1-c]thieno[3,2-e][1,4]thiazines. In contrast with pyrido[2,1-c]thieno[3,2-e][1,4]thiazine derivatives which have no substituent or only one methyl group on the pyridine ring, their 6,8-dimethyl compounds could be smoothly converted by keeping them at room temperature or heating their
重新研究了标题化合物与 2,3-二氯-4,5-二氰基-对苯醌的反应;发现相应的产物不是我们之前描述的环缩和重排的噻吩并[2,3-b]吲哚嗪,而是普通的脱氢化合物,吡啶并[2,1-c]噻吩并[3,2] -e][1,4] 噻嗪。与吡啶环上没有取代基或只有一个甲基的吡啶并[2,1-c]噻吩并[3,2-e][1,4]噻嗪衍生物相比,它们的6,8-二甲基化合物可以顺利合成通过将它们保持在室温下或将其乙醇溶液加热转化为相应的脱硫或重排的 6,8-二甲基噻吩并 [2,3-b] 吲哚嗪衍生物,产率中等至良好。这些吡啶并[2,1-c]噻吩并[3,2-e][1,4]噻嗪和噻吩并[2, 3-b]indolizines 主要基于元素分析和光谱检查;两种化合物的 X 射线分析最终证实了前一种结构,即吡啶并 [2,1-c] 噻吩并 [3,2-e][1,4] 噻嗪。