M. Minabe et al., SYNTHESIS AND PROPERTIES OF 9-(TROPYLIDENEHYDRAZONO)FLUORENE AND RELATED-COMPOUNDS, Bulletin of the Chemical Society of Japan, 71(3), 1998, pp. 693-697
9-(Tropylidenehydrazono)fluorene (1) was obtained by a reaction betwee
n 9-fluorenone hydrazone and tropylium tetrafluoroborate, accompanied
by 9-fluorenone azine, 9-(benzylidenehydrazono)fluorene, and 9,9-ditro
pylfluorene. The amination of 1 occurred at the 2-position of the trop
ylidene moiety. The addition of tosyl isocyanate to 1,gave the [8+2] c
ycloadduct at the 2,4,6-cycloheptatrien-1-imine structure.