Efficient Synthesis of (3E)-3-[Amino(aryl)methylidene]chromane-2,4-diones (=(3E)-3-[Amino(aryl)methylene]-2H-1-benzopyran-2,4(3H)-diones) via a Three-Component Reaction
β‐nitrostyrene (=(2‐nitroethenyl)benzene) 2 in the presence of AcONH4 leads to substituted (3E)‐3‐[amino(aryl)methylidene]chroman‐2,4‐diones (=(3E)‐3‐[amino(aryl)methylene]‐2H‐1‐benzopyran‐2,4(3H)‐diones) 4 (Table 1). High yields, short reaction time, and easy workup are advantages of this novel one‐pot three‐component reaction.