Halogenation Using <i>N</i>-Halogenocompounds. I. Effect of Amines on <i>ortho</i>-Bromination of Phenols with NBS

Abstract

Abstract Primary and secondary amines, especially diisopropylamine and dibutylamine, catalyzed ortho-dibromination of phenol and ortho-monobromination of 2-substituted phenols with NBS in dichloromethane to give selectively 2,6-dibromophenol and 2-bromo-6-substituted phenols, respectively. The effective intermediates are inferred to be N-bromoamines. The scope and limitations of the bromination are also presented.