Acetanilides are converted into 2-chloroquinoline-3-carbaldehydes in good yield by the action of Vilsmeier's reagent in phosphoryl chloride solution. The reaction is shown to involve successive conversion of the acetanilide in to an imidoyl chloride and then an N-(α-chlorovinyl)aniline. The latter enamine is diformylated at its β-position and subsequently cyclised to the chloroquinolinecarbaldehyde
在Vylsmeier试剂在
磷酰
氯溶液中的作用下,
乙酰苯胺以高收率转化为
2-氯喹啉-3-
甲醛。已表明该反应涉及将
乙酰苯胺依次转化为亚
氨酰
氯,然后转化为N-(α-
氯乙烯基)
苯胺。后者的烯胺在其β-位被二甲酰化,随后环化成
氯喹啉甲醛。可以在几种情况下分离二甲酰化的中间体,并分别用多
磷酸环化。