Chromone-2-carboxylic acids decarboxylation

Chromone-5-carboxylic acid, 7-hydroxy-2-methyl-decarboxylation, 3, 711 Chromonecarboxylic acids decarboxylation, 3, 710 Chromone-2-carboxylic acids esters... 

The acid chlorides of several chromone-2-carboxylic acids have been used in the Freidel-Crafts reaction to prepare 2-aroyl-chromones which were pharmacologically active.Decarboxylation of a heterocyclic acid is often a facile reaction but removal of an aldehyde group is unusual. Chromone-3-carboxaldehyde (156) has been decarbonylated by heating with piperidine to give the acrylophenone (157), which cyclized again, with loss of piperidine and one carbon atom. ... 

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