N-bromobutanimide → 3-methyl-5H-dibenzo[a,d]cyclohepten-5-one

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Reaction Steps

The ketone from Step B (30.25 g) and N-bromosuccinimide (29.1 g) were refluxed in carbon tetrachloride (300 ml) for 5 hrs. The solution was cooled, filtered and evaporated and the residue dissolved in dimethylformamide (100 ml) and 1,5-diazabicyclo[4.3.0]non-5-ene (22 g) added. The solution was heated to 80° for 20 mins, then poured into water (300 ml) and extracted with ether (3×300 ml). The extract was washed with dilute aqueous hydrochloric acid and water, then dried and evaporated. Crystallisation from acetone/hexane gave pure 3-methyl-5H-dibenzo[a,d]cyclohepten-5-one (22.2 g). m.p. 81°-83° C.

Provenance & Evidence