Efficient synthesis of chromonylpyrano[c]coumarin, chromonylbenzo[b]pyran, and pyrano[d]pyrimidine in aqueous media

A novel series of functionalized heterocyclic compounds containing the chromone skeleton was achieved by a mild K2CO3(20 %)-catalyzed one-pot three-component reaction of 3-formylchromone, malononitrile, and active methylene compounds or pyrones in aqueous media. Good to high yields, easy workup, and also environmentally friendly character are advantages for this approach.