1,2,3,9-Tetrahydro-4<i>H</i>-carbazol-4-one and 8,9-dihydropyrido-[1,2-<i>a</i>]indol-6(7<i>H</i>)-one from 1<i>H</i>-indole-2-butanoic acid
作者:Richard A. Bunce、Baskar Nammalwar
DOI:10.1002/jhet.22
日期:2009.3
title ring systems have been developed from 1H-indole-2-butanoic acid, which was easily prepared from 2-fluoro-1-nitrobenzene in four steps. Heating 1H-indole-2-butanoic acid in toluene containing p-toluenesulfonic acid at 110°C furnished 1,2,3,9-tetrahydro-4H-carbazol-4-one in 88% yield. Heating this same acid in toluene with no added acid gave 8,9-dihydropyrido[1,2-a]indol-6(7H)-one in 90% yield. The
由1 H-吲哚-2-丁酸开发了标题环系统的有效合成方法,该方法很容易从2-氟-1-硝基苯分四个步骤。在含甲苯的溶液中加热1 H-吲哚-2-丁酸对甲苯磺酸在110℃下以88%的产率提供了1,2,3,9-四氢-4 H-咔唑-4-酮。将该相同的酸在甲苯中加热,不添加酸,以90%的产率得到8,9-二氢吡啶并[1,2 - a ]吲哚-6(7H)-一。这还可以直接以92%的收率制备四氢4 H-咔唑-4-酮通过在110°C的浓盐酸中与铁进行串联还原-环芳构化-酰化反应,合成6-(2-硝基苯基)-5-氧代己酸甲酯。这种方法在五元和七元环的闭合中的应用也很成功。J.杂环化学,(2009)。