Rearrangement of Quinoxalin-2-ones When Exposed to Enamines Generated in Situ from Ketones and Ammonium Acetate: Method for the Synthesis of 1‑(Pyrrolyl)benzimidazolones

The reaction of 3-benzoylquinoxalin-2­(1H)-ones with enamines (generated in situ from ammonium acetate and the corresponding methylaryl­(hetaryl)­ketones) proceeds smoothly to give the corresponding substituted 1-(pyrrolyl)­benzimidazolone derivatives in moderate yields through the novel rearrangement of 3-benzoylquinoxalin-2­(1H)-ones involving a dual cleavage of the C3N4 and C2-C3 bonds under mild conditions.