Pyrrolo[1,2-A]Quinoxalines From Chalcones: An Alternate Route

The synthesis of 2,4-disubstituted pyrrolo[1,2-a]quinoxalines from chalcones is reported. The key steps used are polyphosphoric acid (PPA) assisted acyl rearrangement of the pyrrole ring and Fe catalyzed reduction-cyclization leading to 2,4-disubstituted pyrrolo[1,2-a]quinoxalines. Despite the utilization of comparatively unreactive aromatic ketones, modest to good yields were obtained. (C) 2021 Elsevier Ltd. All rights reserved.