One‐Step Synthesis of 2‐Amino‐3‐cyano‐4‐ aryl‐1,4,5,6‐tetrahydropyrano[3,2‐c]quinolin‐5‐one Derivatives Using KF–Al2O3 as Catalyst

Abstract A series of 2‐amino‐3‐cyano‐4‐aryl‐1,4,5,6‐tetrahydropyrano[3,2‐c] quinolin‐5‐one derivatives were synthesized by the reaction of arylaldehyde, malononitrile, and 4‐hydroxyquinolin‐2‐one in ethyl alcohol at 80°C catalyzed by KF–Al2O3. The structure of the product was confirmed by x‐ray analysis.