A facile approach for the synthesis of novel xanthene derivatives with Vilsmeier–Haack reagent
作者:Oleg K. Farat、Ivan V. Ananyev、Svetlana A. Varenichenko、Ekaterina V. Zaliznaya、Victor I. Markov
DOI:10.1007/s10593-019-02416-6
日期:2019.1
A series of new derivatives of formylxanthenes have been synthesized via the reaction of substituted 1,3-benzoxazines with Vilsmeier–Haack reagent. It has been shown that 1,3-benzoxazines unsubstituted in the aromatic part and 6-bromo-1,3-benzoxazines are rearranged into xanthene derivatives under heating at 80°C for 1.5 h. Substitution at the C-8 position of 1,3-benzoxazines, especially with electronegative
通过取代的1,3-苯并恶嗪与Vilsmeier-Haack试剂的反应,合成了一系列新的甲氧杂蒽衍生物。已经表明,在80℃加热1.5小时,芳族部分中未取代的1,3-苯并恶嗪和6-溴-1,3-苯并恶嗪被重排为into吨衍生物。1,3-苯并恶嗪的C-8位取代,尤其是带负电基团,可显着抑制反应。因此,在C-6和C-8位置存在碘原子会导致反应时间最多增加8小时,而在C-8位置存在溴原子则需要加热到100°C持续11 h。