Approaches to the construction of substituted 4-amino-1H-pyrrol-2(5H)-ones.

Fully substituted 4-aminopyrrolones are easily accessed via simple routes starting from imines, ketones, or α-bromophenyl acetonitriles. Imines were reacted with KCN/NH(4)Cl in aqueous ethanol to produce α-arylamino benzyl cyanides. On the other hand, ketones were transformed to the desired α-amino nitriles using a modified Strecker reaction. Then, α-amino nitrile precursors were allowed to react with a suitable acyl halide to produce the corresponding amides. Further treatment of these amides with ethanolic KOH converted them to highly substituted 4-amino-1H-pyrrol-2(5H)-one derivatives in moderate to excellent yields.