کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
59168 1419451 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ionic-liquid-catalyzed green synthesis of coumarin derivatives under solvent-free conditions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Ionic-liquid-catalyzed green synthesis of coumarin derivatives under solvent-free conditions
چکیده انگلیسی

Brönsted acidic ionic liquids, namely 2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium dihydrogen phosphate, (4-sulfobutyl)tris(4-sulfophenyl)phosphonium hydrogen sulfate, and triphenyl(propyl-3-sulfonyl)phosphonium toluenesulfonate, catalyzed efficient Pechmann condensation of phloroglucinol with β-keto ethyl/methyl esters. 5,7-Dihydroxy-4-methylcoumarin and 5,7-dihydroxy-4-phenylcoumarin were prepared in good to excellent yields under mild, ambient, and solvent-free conditions. Pyrano[2,3-h]coumarins were then prepared by one-pot three-component reactions of 5,7-dihydroxy-4-subsituted coumarin, malononitrile, and aldehydes in the presence of catalytic amounts of Brönsted basic ionic liquids, namely 2-hydroxyethylammonium formate, 3-hydroxypropanaminium acetate, 1-butyl-3-methylimidazolium hydroxide, pyrrolidinium formate, and pyrrolidinium acetate, under thermal solvent-free conditions. The catalysts are environmentally benign and can be easily prepared, stored, and recovered without significant loss of activity.

Graphical AbstractBrünsted acidic ionic liquids catalyzed efficient Pechmann condensations. The reaction of the Pechmann products, malononitrile, and aldehydes in the presence of Brünsted basic ionic liquids for synthesis of pyrano[2,3-h]coumarins was performed.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chinese Journal of Catalysis - Volume 34, Issue 9, September 2013, Pages 1690–1696
نویسندگان
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