hromones were prepared from 2-chlorochromone and α-amino ketones (hydrochloride or ketal derivatives) in ethanol/triethylamine. Their treatment with acetic acid/pyrrolidine led to [1]benzopyrano[2,3-b]pyrrol-4(1H)-ones, which were subsequently functionalized in C2 by aromatic electrophilic substitution (acetylation, bromination or nitration).
由2-氯色酮和在乙醇/三乙胺中的α-氨基酮(盐酸盐或缩酮衍生物)制得2-N-(酰基甲基)氨基色酮。他们用乙酸/吡咯烷处理得到[1]苯并吡喃并[2,3 - b ]吡咯-4(1 H)-一,随后在C2中通过芳香亲电取代(乙酰化,溴化或硝化)进行官能化。