An alternative route to access the pyrano[3,2-c]quinoline or benzo[7,8]-6-azacoumarin core form readily available quinoline N-oxides is presented. The key reaction involves an unusual rearrangement of tetrahydroquinoline-2-ylacetic acids in the presence of triethylamine and acetic anhydride.

中文翻译：

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2-氧吡喃的替代方法[3,2-

提供了获得吡喃并[3,2- c ]喹啉或苯并[7,8]-6-氮杂香豆素核形式的容易获得的喹啉N-氧化物的替代途径。关键反应涉及在三乙胺和乙酸酐存在下四氢喹啉-2-基乙酸的不寻常重排。