A facile synthesis and application of ethyl 6-(bromomethyl)-[1,3]dioxolo[4,5-g]quinoline-7-carboxylate
作者:Yang Li
DOI:10.1007/s11164-014-1581-1
日期:2015.7
Visible-light-induced radical bromination of ethyl 6-methyl-[1,3]dioxolo[4,5-g]quinoline-7-carboxylate (1) was effectively conducted with N-bromosuccinimide using a 150-W tungsten bulb as an initiator, leading to the desired monobromo product ethyl 6-(bromomethyl)-[1,3]dioxolo[4,5-g]quinoline-7-carboxylate (2) in good yield of 76 %. Using the present procedure, a 46 % improvement in yield of 2 was achieved when compared with the previous method used by us. In addition, the trace amount of byproduct was isolated and identified as ethyl 9-bromo-6-methyl-[1,3]dioxolo[4,5-g]quinoline-7-carboxylate (3) based on 1H nuclear magnetic resonance (NMR) spectral analysis. As an extended application of 2, a new synthesis of symmetrical 2-quinolylmethoxyphenyl-containing diethers 11a–c was achieved via Williamson reaction with some dihydroxy arenes (10a–c).
使用 150 瓦钨灯泡作为引发剂,用 N-溴代琥珀酰亚胺有效地对 6-甲基-[1,3]二恶茂并[4,5-g]喹啉-7-羧酸乙酯(1)进行了可见光引发的自由基溴化反应,得到了所需的单溴产物 6-(溴甲基)-[1,3]二恶茂并[4,5-g]喹啉-7-羧酸乙酯(2),收率高达 76 %。与我们以前使用的方法相比,使用本方法 2 的收率提高了 46 %。此外,根据 1H 核磁共振 (NMR) 光谱分析,分离并鉴定出痕量副产品为 9-溴-6-甲基-[1,3]二恶茂并[4,5-g]喹啉-7-羧酸乙酯 (3)。作为 2 的扩展应用,通过 Williamson 与一些二羟基烯(10a-c)的反应,新合成了对称的 2-喹啉基甲氧基苯基二醚 11a-c。