In screening sponsored by the Sational Service Center of the National Cancer Institute, activity against an animal tumor was discovered with a compound presumed (and first reported in 1919) to be 9-o-chlorobenzylidenefluorene. Upon examination, the compound has been found to be 9-o-chlorocinnamylidenefluorene which was produced in small yield as the only recognizable product in an attempted sodium ethoxide-ethanol condensation ...