Reaction of 2-Methoxy-3<i>H</i>-azepine with NBS: Efficient Synthesis of 2-Substituted 2<i>H</i>-Azepines
作者:Christopher E. J. Cordonier、Kyosuke Satake、Mikihiko Atarashi、Yousuke Kawamoto、Hideki Okamoto、Masaru Kimura
DOI:10.1021/jo0500232
日期:2005.4.1
2H-azepine derivatives were formed via base-promoted hydrogen bromide elimination, generally in moderate to quantitative yield. Competitive formation of 4-bromo-2-methoxy-3H-azepine by electrophilic substitutuion or 3H-azepin-2-yl 2H-azepin-2-yl ether by transetherification was minimized at lower reaction temperatures. Quantitative substitution of 2-(2‘,4‘,6‘-trichlorophenoxy)-2H-azepine derivatives, formed
在存在或不存在亲核试剂的情况下,2-甲氧基-3 H-氮杂环庚烷与N-溴琥珀酰亚胺(NBS)的反应产生区域选择性的1,4-加合物,通过碱-形成相应的2 H-氮杂环庚烷衍生物促进了溴化氢的消除,通常产率中等至定量。在较低的反应温度下,通过亲电子取代或3 H-氮杂-2--2-基2 H-氮杂-2-基醚通过醚交换形成的竞争性形成的4-溴-2-甲氧基-3 H-氮杂竞争性最小。从相应的3 H以中等收率形成2-(2',4',6'-三氯苯氧基)-2 H - ze庚因衍生物的定量取代在2,4,6-三氯苯酚(TCP)存在下,通过各种亲核试剂将α-氮杂和NBS得到相应的2-取代的2 H-氮杂。这些亲核试剂中有在3 H-氮杂环庚烷和NBS反应中不耐受的烷硫醇和烷基胺。