N-bromobutanimide → 2-(alpha-bromoethyl)-5H-dibenzo[a,d]cyclohepten-5-one

Participants

Reaction Steps

39.7 Gm. of 2-methyl-5H-dibenzo[a,d]cyclohepten-5-one is refluxed in 1200 ml. of carbon tetrachloride with 35.2 gm. of N-bromosuccinimide for 14 hours, irradiating with a 100 watt incandescent lamp. The solution is cooled, filtered and evaporated. The residue is recrystallized from methylene chloride/hexane to afford 27.3 gm., 51%, of 2-bromomethyl-5H-dibenzo[a,d]cyclohepten-5-one, m.p. 128°-132° C. Use of 2-ethyl-5H-dibenzo[a,d]cyclohepten-5-one gives 80% of 2-(α-bromoethyl)-5H-dibenzo[a,d]cyclohepten-5-one, m.p. 93°-95° C.

Provenance & Evidence