基于3-(苯并咪唑-2-基)喹喔啉-2(1 H)-与1,2-的环收缩,已开发出一种高效且通用的具有两个苯并咪唑片段的喹喔啉衍生物的合成方法。二氨基苯及其各种类型的取代和稠合衍生物。由于分子间和分子内过程,涉及桥联和相邻碳原子的大多数双-苯并咪唑基喹喔啉信号的几种形式之间的自缔合,质子交换,构象和/或互变异构交换,且NMR光谱中的苯并咪唑片段变宽。苯并咪唑片段与分子的喹喔啉核心之间的共轭作用比喹喔啉衍生物(10c)与其噻二唑[ f ]-(17)和吡咯并[ a ]-(19)环化了衍生物,导致整个分子的平面度更大。
The cyclocondensations of benzofuroxan 1a with carbonylcompounds were smoothly and efficiently carried out by the adsorption of the components on the surface of silica gel or a molecular sieve to form a 2,3-disubstituted quinoxaline 1,4-dioxide. When the reactions using a molecular sieve 3A (powder) were carried out at 90°, the actual reaction times were reduced to 0.5-2 hours. Although Duerckheimer