2-Functionalized [1]benzopyrano[4,3-b]pyrrol-4(1H)-ones were obtained by the Fischer-Fink reaction starting from 4-chloro-3-formylcoumarin and different α-amino derivatives (e.g. glycinonitriles, ethyl glycinates and α-amino ketones). In general limitations to the synthetic method arise when α-amino derivatives with very reactive functions were used (e.g. carboxaldehyde groups or their acetal derivatives) leading to Knorr type reactions, or when they contain relatively inactive methylenes (e.g. carboxamide groups) which failed to complete the cyclization process.
从 4-
氯-3-甲酰基
香豆素和不同的 δ-
氨基衍
生物(如甘腈、甘
氨酸
乙酯和 δ-
氨基酮)开始,通过费舍尔-芬克反应获得了 2-官能团化的 [1] 苯并
吡喃并[4,3-b]
吡咯-4(1H)-酮。一般来说,当使用具有高活性功能的δ-
氨基衍
生物(如羧醛基团或其
缩醛衍
生物)导致克诺尔型反应时,或当它们含有相对不活泼的亚甲基(如羧酰胺基团)导致无法完成环化过程时,合成方法就会受到限制。