A facile and efficient synthesis of 2-amino-3-cyano-4H-chromenes and tetrahydrobenzo[b]pyrans using 2,2,2-trifluoroethanol as a metal-free and reusable medium

A highly efficient one-pot three-component regioselective synthesis of 2-amino-3-cyano-4H-chromene and tetrahydrobenzo[b]pyran derivatives has been developed by annulation of aldehydes, malononitrile, and resorcinol or dimedone under reflux conditions in 2,2,2-trifluoroethanol without the use of a catalyst or any other additive.

Graphical abstract2-Amino-4H-chromene and tetrahydrobenzo[b]pyran derivatives were synthesized in excellent yield in 2,2,2-trifluoroethanol.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► In this study we examine the TFE as a new recyclable medium. ► 2-Amino-4H-chromene and tetrahydrobenzo[b]pyran were synthesized in trifluoroethanol. ► This method has the ability to tolerate a wide variety of substitutions. ► TFE was easily recovered.