Reaction of 2-amino-1-azaazulene with diphenylcyclopropenone gave 2,3,
10b-tetrahydro-4,10b-diazabenz[a]azulen-3-one, which rearranged to N-(
1-azaazulen-2-yl)-alpha-cis-stylbenecarboxamide and (1-azaazulen-2-yl)
-alpha-trans-stylbenecarboxamide by heating. Some structures of these
products were determined by the X-ray structure analyses. The reaction
mechanism is discussed.