N-bromobutanimide → 2-Bromofluorenone

Participants

Reaction Steps

Fluorenone (41 grams (g); 0.228 mol) was dissolved in 225 milliliters (ml) of methanesulfonic acid and treated portion wise at room temperature with solid N-bromosuccinimide (NBS) (38.55 g; 0.217 mol). The mixture became dark and warm, and the temperature was maintained below 60° C. by controlling the rate of NBS addition. Upon completion of the NBS addition, the mixture was allowed to cool to room temperature and was poured into 1 liter of ice water. The yellow solid that separated was collected by filtration, washed with copious quantities of water, air dried, and then recrystallized from about 1.5 liters of ethanol. The yield was 40 g (71%) and the product contained 5-10% of 2,7-dibromofluorenone as indicated by LC analysis. A small sample was purified by column chromatography, but in general the contaminated material was carried on in subsequent steps.

Provenance & Evidence