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.
报道了由有机碱1,8-二氮杂双环十一烯(DBU)促进的二氧化碳与
羟基和乙酰氨基苯乙酮的羧化环化反应。该反应利用二氧化碳作为羧化试剂,方便地合成了生物学上重要的化合物4-羟基-2H-香豆素和4-羟基-2(1H)-喹啉酮,产率中等到良好。在
乙酰氨基苯乙酮的反应中观察到从氮到碳的酰基迁移。