Molecular iodine catalyzed one-pot multicomponent reactions for the synthesis of dihydrochromeno[4,3-b]pyrazolo[4,3-e]pyridin-6(7H)-ones

Abstract

A simple and concise method catalyzed by molecular iodine has been reported for the synthesis of a series of dihydrochromeno[4,3-b]pyrazolo[4,3-e]pyridin-6(7H)-ones (1) using a multicomponent domino reaction of aromatic aldehydes, 4-hydroxycoumarin derivatives and 3-aminopyrazoles. The same catalyst was also found useful for the four component reaction of aromatic aldehydes, 4-hydroxycoumarin, benzoylacetonitrile and hydrazine hydrate. The notable advantages of this method are: good yields, no column chromatography, environmentally friendly catalyst and applicability for diversity oriented synthesis of substituted dihydrochromeno pyrazolo pyridin-6(7H)-one scaffolds using both three and four component reactions.