Silica-Grafted Ionic Liquids as Recyclable Catalysts for the Synthesis of 3,4-Dihydropyrano[c]chromenes and Pyra-no[2,3-c]pyrazoles

• 作者: Abolhassan Piran Khodabakhsh Niknam
• 来源期刊: 绿色与可持续化学(英文)
• 学科: 化学
• 关键词: Silica-Grafted N-Propyl-Imidazolium Hydrogen Sulfate Aldehydes Pyrano[2 3-c]-Pyrazoles 3 4-Dihydropyrano[c]-Chromenes Solvent-Free Heterogeneous Ionic Liquid Catalysts
• 年，卷（期）: 2013,（2）
• 页码范围: 1-8
• 页数: 8页
• 分类号: O6

摘要

Silica-grafted N-propyl-imidazolium hydrogen sulfate ([Sipim]HSO4) is employed as a recyclable heterogeneous ionic liquid catalyst for the synthesis of 3,4-dihydropyrano[c]-chromenes by the reaction of aromatic aldehydes, malononitrile and 4-hydroxycoumarin at 100°C under solvent-free conditions. Also, heterogeneous ionic liquid catalyst was used for the synthesis of pyrano[2,3-c]-pyrazoles by the reaction of aromatic aldehydes, malononitrile and 3-methyl-l-phenyl-5-pyrazolone at 110°C under solvent-free conditions. The heterogeneous ionic liquid showed much the same efficiency when used in consecutive reaction runs.