DBU-promoted carboxylative cyclization of o-hydroxy- and o-acetamidoacetophenone (Beilstein Journal of Organic Chemistry)

Abstract The carboxylative cyclization of o-hydroxy- and o-acetamidoacetophenone with carbon dioxide promoted by the organic base 1,8-diazabicycloundec-7-ene (DBU) is reported. This reaction provides convenient access to the biologically important compounds 4-hydroxy-2H-chromen-2-one and 4-hydroxy-2(1H)-quinolinone in moderate to good yields using carbon dioxide as the carboxylation reagent. An acyl migration from nitrogen to carbon is observed in the reaction of o-acetamidoacetophenone. Beilstein J. Org. Chem. 2015, 11, 906–912. doi:10.3762/bjoc.11.102