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Report | Regular issue | Vol 6, No. 8, 1977, pp.1181-1182
Published online, 1st January, 1970
DOI: 10.3987/R-1977-08-1181
A Novel, Mild Preparation of thew 2H-1-Benzopyran-2-one (Coumarin) Ring System

Seppo I. Pennanen*

*Laboratory of Organic Chemistry, Helsinki University of Technology, P.O. Box 6100,FIN-02015 HUT, Espoo, Finland


A facile synthesis of coumarins from o-hydroxycarbonyl compounds and 1-diethylaminopropyne is described. The reaction takes place under very mild conditions, giving coumarins in 38-47% yield. The unwanted sideproducts, the (E)-isomers, produced more coumarins after treatment the reaction mixture with acid, thus bringing the overall yields to 68-84%.