Knowledge Bank

The series: 9-methyl, 9-isopropyl, 9-cyclohexyl, 9,9-dimethyl, 9,9-diethyl, and the unsubstituted parent 2,7-bis (acetamido) fluorene were synthesized from the corresponding 9-substituted fluorenes. The two routes employed consisted of either (1) dinitration, reduction to the diamine, and diacetylation, or (2) Friedel-Crafts diacylation, then rearrangement via the Schmidt reaction. This provides a series of compounds of use in comparing relative carcinogenicity with changes in chemical reactivity as a function of increased steric hindrance due to altered molecular "thickness."