Reactions of 2-Diazo-1,2-Diphenylethanone and Diphenyldiazomethane with Ketohydrazones

Article abstract of DOI:10.1246/bcsj.57.1667

The reactions of 2-diazo-1,2-diphenylethanone (1) with ketohydrazones (3a-c) in equimolecular ratio yield (diphenylacetyl)hydrazones (4a-c) of the corresponding benzophenones which on further treatment with 1 in equimolecular ratio leads to 1-diphenylacetylazo-1,1,3,3-tetraaryl-2-propanones (5a-c).The product 5a is also obtained in the reaction of 1 with benzophenone hydrazone (3a) in 2:1 molecular ratio.The bis(acetylacetonato)copper(II)-catalyzed reaction of 1 and also of diphenyldiazomethane (2) with ketohydrazones (3) affords ketazines (6).The mechanistic route for the formation of products is discussed.