Reaction of α-Oxoketene-<i>N,S</i>-arylaminoacetals with Vilsmeier Reagents: An Efficient Route to Highly Functionalized Quinolines and Their Benzo/Hetero-Fused Analogues
作者:P. K. Mahata、C. Venkatesh、U. K. Syam Kumar、H. Ila、H. Junjappa
DOI:10.1021/jo034053l
日期:2003.5.1
efficient, and regioselective synthesis of functionalized quinolines through Vilsmeier cyclization of a variety of alpha-oxoketene-N,S-anilinoacetals has been reported. The cyclization is found to be facile with N,S-acetals bearing strongly activating groups on aniline, whereas yields of quinolines are moderate in other cases. The reaction could also be extended for the synthesis of substituted tricyclic
据报道,通过多种α-氧代草酮-N,S-苯胺基缩醛的Vilsmeier环化,可以简单,高效且区域选择性地合成官能化的喹啉。发现在苯胺上带有强活化基团的N,S-乙缩醛易于环化,而在其他情况下,喹啉的产率适中。通过进行Vilsmeier反应,该反应还可扩展用于合成取代的三环苯并[h]喹啉,吡啶并[2,3-h]喹啉,4,7-二苯基菲咯啉和四环喹[8,7-h]喹啉分别衍生自1-萘胺,间苯二胺,邻苯二胺和1,5-二氨基萘的N,S-缩醛。对一些新合成的喹啉进行进一步转化,得到2-un取代的(Raney-Ni /乙醇),quinoline-5,通过连续的m-CPBA氧化成相应的(2-甲基磺酰基)喹啉,将8-醌(NBS / H(2)SO(4))或2-烷基/芳基氨基喹啉,然后用适当的胺取代。同样,在微波辐射下用水合肼环化一些2-甲硫基-3-苯甲酰基喹啉,可得到相应的取代和稠合的吡唑并[3,4-b]喹啉,收率很高,而TBTH