103986-39-6Relevant articles and documents
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John,Israelstam
, p. 240 (1961)
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Introduction of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid acid catalyst for one-pot synthesis of substituted coumarins under ultrasonic irradiation
Khaligh, Nader Ghaffari,Shirini, Farhad
, p. 26 - 31,6 (2013)
Poly(4-vinylpyridinium) perchlorate, is a supported, recyclable, eco-benign catalyst for synthesis of substituted coumarins via Pechmann reaction using ultrasound irradiation at room temperature and neat condition in high yields with short reaction times. The catalyst was studied by FT-IR, X-ray diffraction, scanning electron microscope, thermo-gravimetric and energy dispersion X-ray analyses. All the products were extensively characterized by 1H NMR, FT-IR, MS and melting point analyses. This methodology offers momentous improvements over various options for the synthesis of coumarins with regard to yield of products, simplicity in operation and green aspects by avoiding toxic catalysts and solvents. Further, the catalyst can be reused and recovered for several times without loss of activity.
A solvent-free synthesis of coumarins using a Wells-Dawson heteropolyacid as catalyst
Romanelli,Bennardi,Ruiz,Baronetti,Thomas,Autino
, p. 8935 - 8939 (2004)
Seventeen examples are resolved, most of them in good to excellent yields, using the cheap WD catalyst. Substituted coumarins are synthesized from phenols and β-ketoesters by the Pechmann reaction, using a Wells-Dawson heteropolyacid (H6P2W18O62? 24H2O) as catalyst by a solvent-free procedure. This one requires low reaction times, 130°C temperature and as little as 1 mol % of Wells-Dawson acid, obtaining good to excellent yields of coumarins. The catalyst showed to be reusable with no differences in the yields. The results are compared with those of the reactions performed in toluene solution. The presented synthetic procedure is a convenient, clean and fast alternative for synthesizing 4-substituted coumarins (17 examples).
Synthesis of coumarins catalyzed by eco-friendly W/ZrO2 solid acid catalyst
Reddy,Reddy,Giridhar
, p. 3603 - 3607 (2001)
Synthesis of substituted coumarins via reactions of resorcinol and substituted resorcinol with ethyl acetoacetate and ethyl α-methylacetoacetate (Pechmann reaction) are reported, in which the production of environmentally harmful waste streams is minimized by the use of a novel solid acid catalyst.
