Some new mono- and bis(spiro-2-amino-4H-pyrans) are synthesized by the multicomponent condensation reaction of 4-hydroxycoumarin and malononitrile with isatins, ninhydrin, 9,10-phenanthrenequinone, or acenaphthenequinone. Alum was found to be a suitable and efficient catalyst for this condensation.
4-hydroxycoumarin and malononitrile with isatins, ninhydrin, 9,10-phenanthrenequinone, or acenaphthenequinone 的多组分缩合反应合成了一些新的单-和双-(螺-2-
氨基-
4H-吡喃)。研究发现,
明矾是这种缩合反应的一种合适而有效的催化剂。