Efficient synthesis of novel bis(dihydropyrano[2,3c]pyrazoles), bis(4H-chromenes) and bis(dihydropyrano[3,2-c]chromenes) with amide functionality

A synthesis of novel bis(1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles), bis(4H-chromene-3-carbonitriles) and bis(dihydropyrano[3,2-c]chromenes), which are linked to aliphatic spacers via amide linkages was achieved via multicomponent reactions (MCR) of the appropriate bis-aldehyde with two equivalents of both of malononitrile and 3-methylpyrazol-5-one, dimedone or 4-hydroxycoumarin in a basic solution