Green Chemistry: Synthesis of Multisubstituted 4HChromenes in Water

The chromenes are an important class of heterocycles present in numerous bioactive scaffolds
displaying remarkable effects as pharmaceuticals including anticancer, antifungal, antianaphylactin
spasmolytic activity. Several synthetic protocols have been developed for the synthesis of chromene
frameworks, however, most of them suffer from limitations such as, harsh reaction conditions, lack of
generality, tedious work-up and use of toxic solvents. Thus, herein reporting, an expeditious and
environmental friendly, general protocol for the synthesis of 2-Amino-3-Cyano-4H-chromenes via
cascade Knoevenagel-Michael-intramolecular cyclization reaction. The products were obtained in high
(80-95%) yields under catalyst-free reaction in water at room temperature. Pure solid products were
obtained by simple filtration techniques.