作者:Andrey A. Berezin、Christos P. Constantinides、Styliana I. Mirallai、Maria Manoli、Levy L. Cao、Jeremy M. Rawson、Panayiotis A. Koutentis
DOI:10.1039/c3ob41169a
日期:——
1,3-Diphenylbenzo[e][1,2,4]triazin-7(1H)-one, the oxidation product of 1,3-diphenyl-1,4-dihydro-1,2,4-benzotriazin-4-yl (Blatter's radical), reacts with N′-arylbenzamidines in PhMe at ca. 100 °C in the presence of N,N-diisopropylethylamine (Hünig's base) (1 equiv.) to give N′-aryl-N-(1,7-dihydro-7-oxo-1,3-diphenylbenzo[e][1,2,4]triazin-6-yl)benzimidamides in 49–95% yield. In neat AcOH heated at ca. 120 °C, N′–aryl-N-(1,7-dihydro-7-oxo-1,3-diphenylbenzo[e][1,2,4]triazin-6-yl)benzimidamides cyclodehydrate to give the novel 8-substituted 1,3,7-triphenyl-4,8-dihydro-1H-imidazo[4,5-g][1,2,4]benzotriazin-4-yls in 13–81% yield. During the optimization of this cyclodehydration an additional oxazole fused benzotriazinyl radical 1,3,7-triphenyl-1,4-dihydro[1,3]oxazolo[4,5-g][1,2,4]benzotriazin-4-yl was isolated as a side product and characterized. The CV and EPR data of the imidazolo- and oxazolo-fused radicals are presented as well as single crystal X-ray structures of 1,3,7-triphenyl-1,4-dihydro-[1,3]oxazolo[4,5-g][1,2,4]benzotriazin-4-yl and 1,3,7,8-tetraphenyl-4,8-dihydro-1H-imidazo[4,5-g][1,2,4]benzotriazin-4-yl.
1,3-二苯基苯并[e][1,2,4]三嗪-7(1H)-酮,即1,3-二苯基-1,4-二氢-1,2,4-苯并三嗪-4-基(Blatter自由基)的氧化产物,在N,N-二异丙基乙胺(Hünig碱)(1当量)存在下,于约100°C的甲苯中与N'-芳基苯甲脒反应,以49-95%的产率生成N'-芳基-N-(1,7-二氢-7-氧代-1,3-二苯基苯并[e][1,2,4]三嗪-6-基)苯并咪唑胺。在纯乙酸中加热至约120°C时,N'–芳基-N-(1,7-二氢-7-氧代-1,3-二苯基苯并[e][1,2,4]三嗪-6-基)苯并咪唑胺环化脱水,以13-81%的产率生成新型8-取代的1,3,7-三苯基-4,8-二氢-1H-咪唑并[4,5-g][1,2,4]苯并三嗪-4-基。在优化这一环化脱水过程中,还分离出了一种副产物——噁唑并苯并三嗪自由基1,3,7-三苯基-1,4-二氢[1,3]噁唑并[4,5-g][1,2,4]苯并三嗪-4-基,并对其进行了表征。同时提供了咪唑并和噁唑并自由基的CV和EPR数据,以及1,3,7-三苯基-1,4-二氢-[1,3]噁唑并[4,5-g][1,2,4]苯并三嗪-4-基和1,3,7,8-四苯基-4,8-二氢-1H-咪唑并[4,5-g][1,2,4]苯并三嗪-4-基的单晶X射线结构。