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Paper | Regular issue | Vol 45, No. 11, 1997, pp.2131-2136
Published online, 1st January, 1970
DOI: 10.3987/COM-97-7885
Synthesis of 2H-1-Benzopyran-2,4(3H)-dione-3-carboxamide and 2H,3H-[1]Benzopyrano[4,3-b]pyrano-2-hydroxy-3-carboxamide-4,5-dione Derivatives via Carbon Suboxide

Leonardo Bonsignore* and Giuseppe Loy

*Dipartimento Farmaco Chimico Tecnologico, Universita di Cagliari, Via Ospedale 72, I-09124 Cagliari, Italy


The reaction of substituted 2-hydroxybenzmides with carbon suboxide is described. By varying the weight ratio of the reagent, this reaction leads to the coumarin and/or pyranocoumarin derivatives in one step and with satisfactory yields.