A Convenient Synthesis of 5-Aryltropolones via Novel Benzidine Type Rearrangement of 2-(2-Arylhydrazino)tropones

Article abstract of DOI:10.1246/cl.1986.1577

Treatment of a wide variety of 2-(2-arylhydrazino)tropones with ethanolic acid at 50-80 deg C readily gave the benzidine type rearrangement products, i.e. 2-amino-5-(4-aminoaryl)tropones, which in turn were conveniently led to the corresponding 5-aryltropolones that can be utilized for synthesizing B-ring-open analogues of colchicine.