In this paper, a novel and green methodology for the synthesis of 3,4-dihydroquinolizin-2-one derivatives via the tandem reactions of penta-3,4-dien-2-ones with pyridine, quinoline, or isoquinoline at rt in aqueous ethanol was developed. Notably, the reactions involved a convenient work-up of simple precipitation and filtration, and the solvent could be easily recycled. In addition, when the reactions were carried out at higher temperature over a prolonged reaction period, the in situ formed 3,4-dihydroquinolizin-2-ones could be dehydrogenated by molecular oxygen from air to afford quinolizin-2-ones with good efficiency.
本文中开发了一种新型绿色合成方法,通过在常温下用
水乙醇将
三烯-2-
酮与
吡啶、
喹啉或
异喹啉进行
串联反应合成3,4-二
氢喹嗪-2-
酮衍
生物。值得注意的是,这些反应涉及简单的沉淀和过滤操作,且溶剂可以轻易回收。此外,当反应在更高温度下进行较长时间时,原位生成的3,4-二
氢喹嗪-2-
酮可以通过空气中的分子
氧进行
脱氢,生成有效率较高的喹嗪-2-
酮。