Benzofuranyl-pyran-2-ones, -pyridazines, and -pyridones from naturally occurring furochromones (visnagin and khellin)
作者:Eman M. Keshk
DOI:10.1002/hc.10219
日期:——
The novel and versatile enaminones 2a,b were synthesized by treatment of visnaginone methyl ether 1a or khellinone methyl ether 1b with N,N-dimethylformamide dimethylacetal. They were reacted with hippuric acid or N-acetylglycine to yield benzofuran-5-yl-2H-pyran-2-ones 3a–d. The reaction of 2a,b with cyanoacetamide and malononitrile dimer in sodium ethoxide gave benzofuran-5-yl-pyridones 4a,b and
通过用 N,N-二甲基甲酰胺二甲基乙缩醛处理 visnaginone 甲醚 1a 或 khellinone 甲醚 1b 合成了新型多功能烯胺酮 2a、b。它们与马尿酸或 N-乙酰甘氨酸反应生成苯并呋喃-5-基-2H-吡喃-2-酮 3a-d。2a,b 与氰基乙酰胺和丙二腈二聚体在乙醇钠中的反应分别得到苯并呋喃-5-基-吡啶酮 4a,b 和 [苯并呋喃-5-基-1H-吡啶-2-亚基]丙二腈 5a。用水合肼或羟胺回流 2a,b,分别得到苯并呋喃-5-基-1H-吡唑 6a,b 和苯并呋喃-5-基-异恶唑 7a,b。此外,2a,b 在氢氧化钠存在下与芳基重氮盐偶联,生成 3-(benzofuran-5-yl)-2-aryl-hydrazono-3-oxo-propanals 8a,b,它们是合成 3-(benzofuran-5-yl)-2-aryl-hydrazono-3-oxo-propanals