Intermolecular Bromine Transfer of 2-Amino-7-bromotropone Derivatives Catalyzed by Strong Acid
作者:Hidetsugu Wakabayashi、Sumio Ishikawa、Harue Okai、Tetsuo Nozoe
DOI:10.1246/bcsj.58.2840
日期:1985.10
acetic acid containg a trace amount of coned sulfuric acid at 120 °C under nitrogen, 2-bromo-7-(2-hydroxyanilino)tropone (1a) gave 6-bromocyclohepta[b][1,4]benzoxazine (2a) as the main product and cyclohepta[b][1,4]benzoxazine, its 6,8-dibromo derivative and trace amounts of other mono-, di-, and tribromo compounds. This reaction became much more complex in the presence of oxygen. A similar bromine transfer
在氮气下在 120 °C 下加热含有痕量浓硫酸的乙酸后,2-溴-7-(2-羟基苯胺基)托酮 (1a) 得到 6-溴环庚 [b][1,4] 苯并恶嗪 (2a)作为主要产品和环庚[b][1,4]苯并恶嗪、其6,8-二溴衍生物和痕量的其他一、二和三溴化合物。在氧气存在的情况下,该反应变得更加复杂。对于 2-溴-7-(二甲氨基)-、7-(2-羟基-5-甲基苯胺基)-和7-(2-甲氧基苯胺基)托酮,观察到类似的溴转移,尽管分子间溴转移的引用取决于底物的结构和反应条件。相比之下,2a 和 2-amino-5-bromotropone 衍生物对强酸完全稳定。讨论了该溴转移反应的可能反应途径。