A new method for bromination of carbazoles, β-carbolines and iminodibenzyls by use of N-bromosuccinimide and silica gel

Article abstract of DOI:10.1016/S0040-4020(01)90362-X

Carbazole, N-ethylcarbazole, iminodibenzyl (10,11-dihydro-5H-dibenz[b,f]azepine), N-ethyliminodibenzyl and imipramine are readily mono-, di- or polybrominated in high yields at ambient temperature in dichloromethane by use of the appropriate quantity of N-bromosuccinimide in the presence of silica gel. By contrast, the brominations of the β-carbolines, harmane and norharman, are less selective and give mixtures of products, some of which have unusual substitution patterns.