Building libraries of skeletally diverse scaffolds from novel heterocyclic active methylene compound through multi-component reactions

Libraries of skeletally diverse potential bioactive polycyclic/spirocyclic heterocyclic compounds: 2-amino-7, 9-dimethyl-5-oxo-4-aryl-4,5,6,7-tetrahydropyrano[2,3-d]pyrazolo[3,4-b]pyridine-3-carbonitrile, 2'-amino-7',9'-dimethyl-2,5'-dioxo-6',7'-dihydro-5'H-spirorindoline-3,4'-pyrano[2,3-d]pyrazolo[3,4-blpyridine]-3'-carbonitrile, and 5,5'-(arylmethylene)bis(4-hydroxy-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridin-6(7H)-one) have been synthesized through a multi-component reaction using novel heterocyclic active methylene compound 4-hydroxy-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridine-6(7H)-one as one of the building blocks. This protocol can be considered to be an efficient and eco-friendly strategy for diversity oriented synthesis. (C) 2012 Elsevier Ltd. All rights reserved.